Prediction of Physiological Response from Mathematical Models 

Yoram Epstein, Yuval Heled, Daniel Moran, Yair Shapiro

Institute of Military Medicine, Medical Corps, Israel Defense Forces and Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer

The ability to predict the physiological responses of workers exposed to extreme environmental conditions, has been a challenge to environmental physiologists for more than 3 decades. Therefore, mathematical models have been developed to predict metabolic rate under various levels of work intensity and dynamic changes in body temperature and heart rate.

Based on the effect of exercise on the cardiovascular system, a model was developed to predict mean arterial blood pressure as a function of heart rate. Physiological strain could also be estimated on the basis of thermoregulatory and cardiovascular strains.

This paper summarizes knowledge accumulated during 25 years of studies in the field of mathematical modeling of physiological parameters. Besides analyzing the logic underlying each model, it explains the scientific approach in developing a model from its early concept to the model's application in the field.

Pre-Induction Sport Activity in Prevention of Stress Fractures 

Aharon S. Finestone, Arieh Eldad, Charles Milgrom

Medical Corps, Israel Defense Forces, and Dept. of Orthopedics, Rabin Medical Center, Beilinson Campus, Petah Tikva and Hadassah University Hospital, Ein Kerem, Jerusalem

Pre-induction sports participation of 392 elite infantry recruits was evaluated for correlation with incidence of stress fractures (SF) during 14 weeks of basic training. 23.7% developed lower extremity stress fractures. 72% of the recruits had participated in sports on a regular basis during the 2 years prior to induction. Their fitness as examined by the Bar-Or induction fitness test, was significantly better than that of those who had not trained. 14.9% of the soldiers who had previously participated in ball games (primarily basketball) as an only sport suffered stress fractures, compared to 31.0% of those whose only sport was running (p<0.005).

Training for only 6 months prior to induction had no effect on the incidence of SF. The reason for the difference between ball games and running is probably related to the higher strains and strain rates developed during ball games and to their multidirectional nature, as compared to running.

These findings suggest that participation in a pre-induction program that includes activities that create strains, such as basketball, can reduce incidence of SF in infantry recruits. The training period has to last at least 2 years.

Man in a Hot Climate - Early Studies of the Institute of Military Physiology 

Ezra Sohar, Yair Shapiro, Yoram Epstein

Institute of Military Medicine, Medical Corps, Israel Defense Forces and Heller Institute of Medical Research, Sheba Medical Center, Tel Hashomer

In the 1950's many IDF soldiers were hospitalized for heat stroke - about 25% of whom died. Analyzing these cases revealed that commanders misinterpreted human ability to perform in the heat and ignored basic concepts of fluid and electrolyte balance and heat load.

In the early 1960's a series of studies was conducted with regard to soldiers' performance in the heat. The first study (1959), which later became a classic, was conducted during a 21-day march from Eilat to Metula, crossing all climatic zones of Israel. The study was followed by other investigations which approached the issues of voluntary dehydration, fluid consumption vs sweat loss, salt additives, and the effect of heat load on performance.

Based on these early studies, proper regulations were issued to field officers. Over the years, the lessons learned from these studies saved many lives. The number of cases of heat stroke and of other climate-related injuries was dramatically reduced, and performance was enhanced.

Military Psychiatry in Israel: a 50-Year Perspective 

Avi Bleich

Tel Aviv-Souraski Medical Center and Sackler Faculty of Medicine, Tel Aviv University

The history of military psychiatry in Israel may be divided into 2 main periods. The first extended from the War of Independence in 1948, through the Sinai, Six Day and Yom Kippur Wars. Its outstanding feature was avoidance of the issue of combat stress reaction (CSR). The Yom Kippur War made the recognition of CSR inescapable, assisted in breaking up denial, and served as a stimulus for development of the next phase of the system.

This second phase was characterized by impressive progress in all areas of military psychiatry. The rich experience accumulated during the wars, together with the assimilation of a research culture which began blooming, especially in the wake of the Lebanon War, aided the development and crystallization of concepts related to combat and non-combat military psychiatry alike. The build-up of the mental health organization overlapped field deployment of the Medical Corps.

New Psychopharmacological Approaches in Mental Health as Applied by the Israel Defense Forces

Moshe Zvi Abramowitz, M. Shmushkevich, Avraham Weizman, Mordechai Mark

Mental Health Department, Medical Corps, Israel Defense Forces; Sackler Faculty of Medicine, Tel Aviv University; Jerusalem Mental Health Center; and Geha Psychiatric Hospital

In the past decade there have been far-reaching developments in psychopharmacology. Previously, only a few classes of medication were at the disposal of psychiatrists, as many had serious side effects that limited their use. Now our psychopharmacological armamentarium has grown considerably, allowing for greater choice of treatment in the military.

We review these developments, and discuss the special considerations to be taken into account when treating soldiers with psychiatric medication. We discuss suitable medication for ongoing outpatient treatment, as well as the standard list of medication currently used by units deployed in the field.

Advances in psychopharmacologic treatment should enable more soldiers to serve safely in the military with fewer restrictions on their duties.

Burn Injuries During the Six Day War 

Uriel Y. Dreyfuss

Dept. of Orthopedics, Bnai Zion Medical Center, Haifa

About 2500 soldiers were injured during the Six Day War (June 1967) of whom 115 suffered from burns. In 34 of them 15% or more of their body surface was involved and 11 died. Typical features of these burn cases were supplementary injuries, a high rate of infection, and long periods of hospitalization. Prophylactic antibiotics were not useful. The general condition of many deteriorated during the first week after injury, indicating the importance of treating severe burns in specialized facilities.

Medical Support During The Sinai War Of Attrition (1968-1970): A 30-Year Perspective 

Z. Gimmon, J. Adler

Dept. of General Surgery, Hadassah-Hebrew University Medical Center, Ein Kerem, Jerusalem and Medical Section, Israteam, Lod

The War of Attrition between Israel and Egypt along the Suez Canal line lasted 23 months (9/1968-8/1970), during which the Israel Defense Forces (IDF) were mostly in fixed fortifications. A few of the important principles of field medical support, which became cornerstones of IDF procedure, were established during that war. These included use of armored vehicles for evacuation under artillery fire, as well as emergency treatment, physiological stabilization, and maintenance of the wounded until evacuation.

The latter objectives were achieved by stationing medical officers and paramedics within the fortifications, where they remained with the troops. A field surgical hospital was established in Refidim which had a trained surgical staff and a well-equipped emergency department. It included an operating theater and post-op recovery facilities for proper surgical care until evacuation to hospitals in the rear.

Tables showing the number of casualties throughout 1 year of the War of Attrition are presented. Better personal shielding by helmets and body shields decreased the number and severity of head and thoraco-abdominal injuries. The relative large number of those who died-of-wounds was due to the proximity of medical facilities, so that treatment could be administered within the fortifications. Otherwise, many more would have been included among the killed-in-action.

Israel Naval Medical Institute: 20 Years of Applied Research, and Future Goals 

Ran Arieli, Avi Shupak

Israel Naval Medical Institute, Medical Corps, Israel Defense Forces

The Israel Naval Medical Institute (INMI) is unique as a research center located in a naval base and having close inter-relations with naval underwater units. It is ideal for applied research, and for mutual exchange of needs and of ideas and instructions.

Factors making this institute so suitable for applied research include: direct personal communication with combat divers, professional naval divers, submariners, civilian recreational divers and professional civilian divers, as well as naval vessel crews prone to seasickness; hyperbaric oxygen therapy is administered in cooperation with a large neighboring hospital.

Close spatial and personal relations with an academic institution (the Technion, with its Faculties of Medicine, Biology and Biophysics) provide a basis for cooperative research which expands research capabilities, and allows access to extensive expertise, instrumentation and equipment. Close ties with physicians who served at the INMI in the past also bring them into this research community.

During their specialization, physicians may spend up to 6 months working with us on a research project. Undergraduate, graduate and post-graduate students may complete their research at our institute with the agreement of their parent academic institutions.

Much of the research can be released to the international community. However, some is classified, serves only internal needs or is not of public interest. The number of published papers has stabilized since 1991 at about 16 a year.

Studies of gas exchange and oxygen toxicity originate mainly in the Hyperbaric Research Unit, research on motion sickness in the Motion Sickness and Human Performance Laboratory, and work on hyperbaric and diving medicine in the Clinical Section of the INMI.
 

Decompression Sickness in Divers Treated at the Israel Naval Medical Institute 

A. Gil, A. Shupak, H. Lavon, Y. Adir

Israel Naval Medical Institute, Israel Defense Forces, Haifa

Clinical characteristics of 125 divers treated for decompression sickness (DCS) in the hyperbaric multiplace chambers of this Institute during 1992-1997 were analyzed retrospectively. In 62 (51%) the diagnosis was DCS Type I (joint pain or skin involvement) and in 60 (49%) DCS Type II (neurological, inner ear or pulmonary disease). Risk factors for the evolution of DCS were depth and duration of the dives involving accidents, violation of recommendations of the decompression tables, and repeated dives.

Results were available for 112 of the 125 patients. 54 of them (48%) recovered completely, and another 54 recovered partially; 4 did not respond to treatment. Inner ear DCS was less responsive to hyperbaric oxygen treatment (p=0.0001). There was significant improvement of neurological function in those with severe neurological injury (p=0.0001). Rapid diagnosis and transportation of divers with DCS to a hyperbaric chamber is of crucial importance.

Trends in Epidemiology of Hepatitis in the Israel Defense Forces 

Michael Gdalevich, David Gillis, Daniel Mimouni, Itamar Grotto, Ofer Shpilberg

Institute of Military Medicine, Medical Corps, Israel Defense Forces

During the 50's and 60's there were large scale epidemics of hepatitis A every 3-4 years in the Israel Defense Forces. During these epidemics the annual incidence exceeded 10/1000 soldiers at risk. There has been a highly significant decrease in rates during the past 30 years. The average annual incidence of clinically identified viral hepatitis A decreased from an average of 6/1000 during the 60's to 2.5/1000 during the 70's. The decrease coincided with the introduction in the 1970's of wide-scale post-exposure prophylaxis with immune serum globulin (ISG). The incidence was further significantly reduced to 0.5-1.0/1000 with the introduction of pre-exposure prophylaxis with ISG, starting in 1978 (p<0.001).

Other factors probably played a role in accelerating the decline in morbidity, such as improvement in personal hygiene and sanitation facilities, and in waste disposal and other aspects of military environmental health.

These improvements were probably more pronounced in the civilian sector, leading to decreased exposure of children to the virus and consequently a higher proportion of seronegatives at induction. Increase in the proportion of recruits without natural immunity to the virus poses greater risk, both in terms of personal morbidity as well as military operational ability. This risk, combined with problems of ISG use and availability, has propelled hepatitis A prevention policy towards the use of the new inactivated vaccines.

Development of Molecular Tests for Rapid Detection of Enteropathogens 

Miri Yavzori, Nir Uriel, Nurith Porat, Ron Dagan, Ruhama Ambar, Ofer Shpilberg, Dani Cohen

Army Health Branch Research Unit, Medical Corps, Israel Defense Forces; Pediatric Infectious Disease Unit, Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba; and Sackler Faculty of Medicine, Tel Aviv University

Amplification of specific DNA sequences by polymerase chain reaction (PCR), enables rapid, sensitive and direct, specific identification of pathogens at very low concentrations in clinical samples. Studies in recent years have reported identification of several enteropathogens directly from stool samples by PCR. The amplification process includes the use of primers complementary to the DNA sequences specific to the pathogen, thus relying on the pathogen's genotype, rather than its phenotype on which identification by the methods of classical microbiology were based.

We have developed PCR protocols for the differential identification of enteropathogens resembling the normal flora (enterotoxigenic E. coli (ETEC), E. coli O-157), Shigella spp, and the detection of enteropathogens that can not be grown on classic growth media (Norwalk virus). The amplification process is inhibited by several substrates present in fecal material (phenol, hemoglobin), limiting DNA extraction by phenol. The protocols we have developed for direct detection of Shigella spp and ETEC in stools circumvent inhibition of PCR by the use of a 4-hour pre-enrichment step in brain-heart infusion broth.

Rapid and accurate identification of enteropathogens is important for prompt and focused intervention to stop the chain of transmission in outbreaks of gastroenteritis in military and civilian populations.

Jet Lag Causing or Exacerbating Psychiatric Disorders

Gregory Katz, Rimona Durst, Josef Zislin, Hilla Knobler, Haim Y. Knobler

Kfar Shaul Mental Health Center, Jerusalem (Affiliated with the Hebrew University-Hadassah Medical School, Jerusalem)

Desynchronization of circadian rhythmicity resulting from rapid travel through at least 4 time zones leads to symptoms of jet lag syndrome. The most commonly experienced symptoms in normal individuals are sleep disorders, difficulties with concentrating, irritability, mild depression, fatigue, and gastrointestinal disturbances.

There is strong evidence relating affective disorders to circadian rhythm abnormalities, such as occur in jet lag. Less convincing suggestions relate jet lag to psychosis. We presume, relying on the literature and our accumulated experience, that in predisposed individuals jet lag may play a role in triggering exacerbation of, or de novo affective disorders, as well as, though less convincing, schizophreniform psychosis or even schizophrenia. An illustrative case vignette exemplifies the possible relationship between jet lag following eastbound flight and psychotic manifestations.

Color Doppler Imaging of Central Retinal Artery in Retinopathy of Prematurity

Alon Harris, Hanna J. Garzozi, Mira Harris-Izhak, Nir Shoham, Daniel R. Holland

Depts. of Ophthalmology, Indiana University School of Medicine, Indianapolis and of HaEmek Medical Center, Afula; and Eye Health Northwest, Portland, Oregon

Color Doppler imaging (CDI) is a noninvasive technique, combining 2-dimensional brightness-modulated (B-mode) ultrasound evaluation of eye and orbital structures, with simultaneous color-coded Doppler imaging of orbital blood flow. It has been used to characterize various ophthalmic disorders in adults. Currently there is no data describing orbital blood flow parameters in either normal children or in those with ophthalmic disease, such as the retinopathy of prematurity (ROP).

We evaluated blood flow in the central retinal artery of preterm infants undergoing examination for ROP. We also investigated whether useful readings could be obtained on a consistent basis, and the reproducibility of differences in central retinal artery blood flow between subjects with and without ROP (including the influence of "plus" disease).

We obtained hemodynamic readings in 43 of 46 eyes of preterm infants. 13 eyes had no signs of ROP; 18 had ROP (at least stage 1) without "plus" disease, and 12 had ROP with "plus" disease. There were no statistically significant differences in systolic blood flow velocity within the 3 groups. However the average velocity was slower in the "plus" disease group, correlating with the clinical finding of dilated and tortuous blood vessels which characterize the posterior retina of ROP eyes with "plus" disease.

Use of Civilian Emergency Departments by Israel Defense Force Soldiers 

A.D. Cohen, A. Porath, R. Bessorai, A. Shulman, Y. Snir

Medical Corps, Israel Defense Forces; Depts. of Medicine F and Orthopedics and Emergency Dept., Soroka University Medical Center and Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheba

Many physicians, civilian as well as in military, feel that some referrals of soldiers to civilian emergency departments are inappropriate and that soldiers should receive medical attention within their military units. We therefore evaluated referrals of soldiers to our emergency department.

707 referral letters from military physicians and the corresponding emergency room discharge letters were evaluated. Most soldiers were referred for mild trauma (45.0%) or miscellaneous diseases (52.9%); 22 (3.1%) were hospitalized.

It appears that some military physicians use the civilian hospital emergency department as a surrogate for an out-patient specialty clinic and for x-ray and laboratory services. This is in contrast to the designated functions of the emergency department which are to provide emergency and trauma services and to evaluate the need for hospitalization of referred patients.

Tacrolimus does not Accentuate Hepatic Damage due to Hypoperfusion 

Ron Ben Abraham, Ivgeni Isartal, Richard Nakache, Vallery Rudick, Daniel Ogorek, Gideon Paret, Avi Weinbroum

Dept. of Anesthesiology and Critical Care Medicine, Organ Transplantation and Postoperative Care Units, Tel Aviv-Sourasky Medical Center; and Pediatric Intensive Care Units, Sheba Medical Center, Tel Hashomer; and Sackler Faculty of Medicine, Tel Aviv University

Deterioration of hepatic function following liver transplantation is a known complication, sometimes attributed to the use of cyclosporin A. Reaction to tacrolimus (Prograf), a relatively new and effective immunosuppressant drug, is thought to result in a much lower grade of organ dysfunction, especially in the transplanted liver.

Using the ex-vivo rat model of isolated perfused liver, we evaluated hepatocellular damage and oxygen extraction when tacrolimus was administered following liver hypoperfusion. Tacrolimus did not worsen hepatic dysfunction caused by the hypoperfusion. Therefore using tacrolimus in the perioperative period might be safer than cyclosporin A, which tends to worsen hepatic damage in the presence of hypoperfusion.

Mitral Valve Repair in Ischemic Cardiomyopathy with Severeleft Ventricular Dysfunction

Dani Bitran, Ofer Merin, Jeffrey Fisher, Nadiv Shapira, Marc W. Klutstein, Shuli Silberman

Depts. of Cardiothoracic Surgery, Anesthesiology and Cardiology, Shaare Zedek Medical Center, Jerusalem

Patients with ischemic mitral insufficiency and poor left ventricular function are high operative risks. We present 101 patients who had mitral valve repair in our department: 21 had severely reduced left ventricular function, 19 were in NYHA functional Class IV, and 2 in Class III. All had concomitant coronary artery bypass.

There was no early operative mortality, but there were 2 late deaths (9.6%). At follow-up (3-36 months) all valves were functioning normally, 9 patients (43%) were in NYHA functional Class I, and 4 (19%) in Class II.

Our experience shows that repair of ischemic mitral insufficiency in the presence of severe left ventricular dysfunction can be performed with good results, and is preferable to mitral valve replacement. Late follow-up showed significant symptomatic improvement.

Breast Cancer after Mantle Field Irradiation for Hodgkin's Disease 

A. Katz, B. Brenner, A. Sulkes, H. Luria, G. Marshak, E. Fenig

Oncology Institute, Rabin Medical Center, Beilinson Campus, Petah Tikva and Sackler Faculty of Medicine, Tel Aviv University

Effective use of modern therapeutic modalities results in the cure of 75%-80% of Hodgkin's disease patients, regardless of stage. The major threat to continued survival is, therefore, not recurrent disease but development of second malignancies. Recent reports have firmly established the increased risk of breast cancer developing in women treated with mantle field irradiation.

We describe 3 women who developed breast carcinoma following mantle field irradiation for Hodgkin's disease. Their clinical course was consistent with that reported in larger series. They were relatively young when irradiated and there was a long interval between radiation therapy and the diagnosis of breast cancer.

Review of the literature shows that there may be a role for prophylactic mastectomy after irradiation for Hodkgin's disease.

Concomitant Coronary Artery Bypass Surgery and Pulmonary Lobectomy 

Amit Korach, Uzzi Izhar, Ehud Rudis, Amir Elami

Dept. of Cardiothoracic Surgery, Hadassah University Hospital, Jerusalem

Coronary artery disease amenable to percutaneous interventions or coronary artery bypass grafting, and resectable lung cancer are major causes of morbidity and mortality. We present our experience in the treatment of 3 patients (men aged 64 and 66 and a woman of 77) who each had significant coronary artery disease and a resectable lung tumor. They underwent combined coronary artery bypass grafting and pulmonary lobectomy.

We conclude from our experience and review of the literature that concomitant surgery in such cases is safe and effective, decreases suffering, and decreases the cost of 2 separate invasive procedures.

Israel Hospital Pharmaceutical Services: A National Survey 

S. Livny, A. Hammerman, S. Shani, J. Shemer

Hiliel Yaffe Medical Center, Hadera; Israel Center for Technology Assessment in Health Care; Gertner Institute, Tel HaShomer; Dept. of Internal Medicine, Sheba Medical Center, Tel HaShomer; and Sackler School of Medicine, Tel Aviv University

Results of a 1996 survey of hospital pharmaceutical services in Israel are presented. A questionnaire was mailed to 46 pharmacy directors in Israel hospitals of which a total of 33 were returned (72%).

The main services provided at hospital pharmacies are production of pharmaceuticals and inventory management. The pharmacy directors estimated that more then half of their pharmacists' time was spent on technical work that did not need their academic, professional knowledge. In Israel general hospitals there are on the average 1.23 full time pharmacist positions per 100 hospital beds and 1.09 positions for other pharmacy employees.

A similar survey carried out in the United States showed an average of 7.4 pharmacists per 100 hospital beds. Pharmacists there have broad clinical roles which, in general Israeli pharmacists do not have.

Computer systems are used in our pharmacies mainly for inventory management. About half of the directors did not think that the location, structure and furnishings of their pharmacy were appropriate for its role.

Under current conditions, Israel hospital pharmacies are not organized to provide pharmaceutical services beyond inventory management and pharmaceutical production. Appropriate budgets and personnel are required to develop clinical pharmacy services at Israel hospitals. This would lead to improved quality of drug treatment and cost-containment and would allow pharmacists to exploit their knowledge, skills and training that under the current system, are only partially utilized.

Thallium Scan and Pulmonary Carcinoma 

Adam Mor, Amit Segev, Rami Herskoviz, Yoseph A. Mekori

Dept. of Medicine B, Meir General Hospital, Kfar Saba Affiliated with Sackler Faculty of Medicine, Tel Aviv

A 70-year-old man was admitted for exacerbation of congestive heart failure. In his assessment thallium scan of the heart was performed. An incidental finding was a focus of absorption in the right lung. The lesion was later diagnosed as adenocarcinoma based on the cytological findings.

Prader-Willi Syndrome: Medical, Emotional and Cognitive Facets

Varda Gross-Tsur, Yael E. Landau

Neuropediatric Unit, Shaare Zedek Medical Center, Jerusalem

Prader-Willi syndrome, first described in 1956, is characterized by marked hypotonia, hyperphagia, severe obesity, short stature, hypogonadism, orthopedic problems, breathing- related sleep disorders, mild to moderate mental retardation and behavioral abnormalities. The incidence of this syndrome, an expression of a genetic imprinting error in chromosome 15, is 1:10,000-1:25,000.

We describe the medical, emotional and cognitive parameters of 34 patients in our multidisciplinary clinic for Prader-Willi syndrome. Their ages range from 5 months to 40 years and 20 are males. Excessive weight gain started at the age of 6 years, increasing to 170-370% of that predicted by height and age and short stature started after the age of 12. All males have hypogonadism; 6 patients have scoliosis. Breathing-related sleep disorders have occurred in 15.

Children above the age of 8 years underwent neuropsychological assessment: half (9/18) have borderline intelligence while a quarter have low-normal intelligence and the remainder mild to moderate mental retardation. Behavioral and social problems are common, and become more prominent during adolescence. ADHD was diagnosed in 10/18.

Whole Bowel Irrigation in Infants for Acute Iron Poisoning 

Nir Sokolover, Avinoam Rachmel

Pediatric Dept. A, Schneider Children's Medical Center; Rabin Medical Center, Petah Tikva; and Tel Aviv University Medical School

Acute iron poisoning is a major cause of death due to poisoning in children, so knowledge of its presentation and appropriate management are necessary. Whole bowel irrigation, used routinely in preparation for elective surgery and colonoscopy, are safe and effective procedures. In recent years whole bowel irrigation has been used several times in various toxic situations, including acute iron poisoning.

We report our successful experience treating acute iron poisoning in a 1-year-old girl using whole bowel irrigation and deferoxamine. The safety and theoretical effectiveness of the procedure, although not proven in controlled clinical studies, suggests the use of whole bowel irrigation as treatment for acute iron poisoning.

Scaphoid Fractures in Children  

Shalom Stahl

Hand Surgery Unit, Rambam Medical Center and Rappaport Faculty of Medicine, Israel Institute of Technology, Haifa

The scaphoid is the most common carpal bone fractured in adults. In children the fracture is distinctly uncommon. We present our experience with 23 children treated between 1987-1998, 19 of them with fractures in the distal third of the wrist; there were 11 avulsions, 4 waist fractures, and 12 were undisplaced. The mechanism of injury was a direct blow or a fall onto the outstretched hand. Immobilization in a plaster cast led to union in all except 1 case.

Based on our experience and study of the literature, it is evident that scaphoid fractures, although uncommon, do occur. Thorough clinical and radiological examination of children with a forearm or wrist injury is important in detecting such fractures.