Israel Medical Association Journal

Background: Superantigens produced by Staphylococcus aureus and Streptococcus pyogenes are among the most lethal of toxins. Toxins in this family trigger an excessive cellular immune response leading to toxic shock.

Objectives: To design an antagonist that is effective in vivo against a broad spectrum of superantigen toxins.

Methods: Short peptide antagonists were selected for their ability to inhibit superantigen-induced expression of human genes for cytokines that mediate shock. The ability of these peptides to protect mice against lethal toxin challenge was examined.

Results: Antagonist peptide protected mice against lethal challenge with staphylococcal enterotoxin B and toxic shock syndrome toxin-1, superantigens that share only 6% overall amino acid homology. Moreover, it rescued mice undergoing toxic shock. Antagonist peptides show homology to a β-strand/hinge/a-helix domain that is structurally conserved among superantigens, yet remote from known binding sites for the major histocompatibility class II molecule and T cell receptor that function in toxic T cell hyperactivation.

Conclusions: The lethal effect of superantigens can be blocked with a peptide antagonist that inhibits their action at the top of the toxicity cascade, before activation of T cells occurs. Superantigenic toxin antagonists may serve not only as countermeasures to biologic warfare but may be useful in the treatment of staphylococcal and streptococcal toxic shock, as well as in some cases of septic shock.
 

Background: The ear is the most frequent organ affected during an explosion. Recognition of possible damage to its auditory and vestibular components, and particularly the recovery time of the incurred damage, may help in planning the optimal treatment strategies for the otologic manifestations of blast injury and preventing deleterious consequences.   

Objective: To report the results of the oto-vestibular initial evaluation and follow-up of 17 survivors of a suicidal terrorist attack on a municipal bus.

Methods: These 17 patients underwent periodic ear inspections and pure tone audiometry for 6 months. Balance studies, consisting of electronystagmography (ENG) and computerized dynamic posturography (CDP) were performed at the first time possible.

Results: Complaints of earache, aural fullness and tinnitus resolved, whereas dizziness persisted in most of the patients. By the end of the follow-up, 15 (55.6%) of the eardrum perforations had healed spontaneously. Hearing impairment was detected in 33 of the 34 tested ears. Recovery of hearing was complete in 6 ears and partial in another 11. ENG and CDP were performed in 13 patients: 5 had abnormal results on CDP while the ENG was normal in all the patients. The vertigo in seven patients resolved in only one patient who was free of symptoms 1 month after the explosion.

Conclusion:  Exposure to a high powered explosion in a confined space may result in severe auditory and vestibular damage. Awareness of these possible ear injuries may prevent many of the deleterious consequences of such injuries.
 

Background: The bladder tumor antigen stat is a simple and fast one-step immunochromatographic assay for the detection of bladder tumor-associated antigen in urine.

Objectives: To evaluate the BTA[1] stat in non-bladder cancer patients in order to identify the categories contributing to its low specificity.

Methods: A single voided urine sample was collected from 45 patients treated in the urology clinic for conditions not related to bladder cancer. Each urine sample was examined by BTA stat test and cytology.

Results: The overall specificity of the BTA stat test was 44%, which was significantly lower than that of urine cytology, 90%. The false positive rates for BTA stat test vary among the different clinical categories, being highest in cases of urinary tract calculi (90%), and benign prostatic hypertrophy (73%). Exclusion of these categories from data analysis improved BTA stat specificity to 66%.

Conclusions: Clinical categories contributing to low BTA stat specificity can be identified, and their exclusion improves the specificity of this test.

Background: Leiomyoma is the common benign tumor of the female genital tract. The traditional treatment is hysterectomy, myomectomy or medical therapy by hormonal manipulation. Uterine arterial embolization, a recognized treatment for acute pelvic hemorrhage, has recently been applied to the management of non-acute uterine hemorrhage due to leiomyoma.

Objective: To describe our experience with uterine arterial embolization for the management of uterine fibroid.

Methods: Uterine arterial embolization was performed in nine patients with leiomyomas in whom medical therapy failed and who sought to avoid surgery.

Results: Follow-up ultrasound examination after 2 months revealed an average reduction in fibroid volume of 38%. There were no early or long-term complications.

Cunclusions: Uterine arterial embolization appears to be effective and safe in the management of symptomatic leiomyomas. It is a promising alternative to myomectomy or hysterectomy and warrants further investigation in this setting.
 

Background: Following the recent drought in Ethiopia, the Jewish Agency, aided by the Israel Ministry of Foreign Affairs, launched a medical relief mission to a rural district in Ethiopia in May-August 2000.

Objectives: To present the current medical needs and deficiencies in this representative region of Central Africa, to describe the mission’s mode of operation, and to propose alternative operative modes.

Methods: We critically evaluate the current local needs and existing medical system, retrospectively analyze the mission’s work and the patients’ characteristics, and summar­ize a panel discussion of all participants and organizers regarding potential alternative operative modes.

Results: An ongoing medical disaster exists in Ethiopia, resulting from the burden of morbidity, an inadequate health budget, and insufficient medical personnel, facilities and supplies. The mission operated a mobile outreach clinic for 3 months, providing primary care to 2,500 patients at an estimated cost of $48 per patient. Frequent clinical diagnoses included gastrointestinal and respiratory tract infections, skin and ocular diseases (particularly trachoma), sexually trans­mitted diseases, AIDS, tuberculosis, intestinal parasitosis, malnutrition and malaria.

Conclusions: This type of operation is feasible but its overall impact is marginal and temporary. Potential alternative models of providing medical support under such circum­stances are outlined.
 

Background: The neurosteroids dehydroepiandrosterone (DHEA) and its sulfated metabolite (DHEAS) have been reported to possess neuroprotective as well as anti-tumoral activity in vitro and in vivo.

Objectives: To compare the effect of the two neurohor­mones on cell viability in primary whole-brain fetal mouse culture and isolated neuronal culture, as well as in a human neuroblastoma cell line (SK-N-SH).

Methods: Cell viability and cell proliferation were deter­mined with the neutral red and ³H-thymidine uptake methods, Apoptosis in propidium iodide-stained neuroblastoma cells was determined using flow cytometry.

Results: DHEA (1 nM-10 ìM) decreased the viability of selected primary neuronal cells (33-95% after 24 and 72 hours) but not of whole-brain cultured cells (neuron+glia). DHEAS did not significantly modify cell viability in either primary culture. In a human neuroblastoma cell line, DHEA (1 nM- 1 ìM) decreased ³H-thymidine uptake (30-60%) and cell viability (23-52%) after 24 hours. DHEAS did not significantly modify, or only slightly stimulated, cell viability and uptake of  ³H-thymidine (132% of controls). The combination of DHEA and DHEAS neutralized the toxic effect of DHEA in both primary neuronal culture and neuroblastoma cell line. Flow cytometric analysis of DNA fragmentation in neuroblastoma cells treated with 100 nM DHEA/DHEAS for 24 hours showed an increase in apoptotic events (31.9% and 26.3%. respec­tively, vs. control 2.54%).

Conclusions: Our results do not confirm a neuroprotective role for DHEA and suggest that DHEA and DHEAS have a differential role: DHEA possesses a neurotoxic (expressed only in isolated neurons) and anti-proliferative effect DHEAS demonstrates only a slight neuroprotective effect.
 

Background: The method of midline Iaparotomy incision and closure remains a complex surgical problem.

Objective: To compare the mechanical properties at the interface of midline laparotomy incision made by scalpel versus electrocutting current in rats.

Methods: A sharp midline laparotomy incision was made in 60 Wistar female rats using a scalpel or electrocautery to open the fascia. The fascial and skin wounds were closed separately with a continuous nylon. Fascial specimens were analyzed for mechanical properties at the midline incision using a loading machine. The load-extension curve was recorded during tensile loading at a steady extension rate of 15 mm/mm.

Results: There was no statistically significant difference between the two groups in either wound-bursting force (PPEAK) or the strain energy spent until the point of measured PPEAK. Each load-extension curve showed a characteristic pattern in all rats. Tissue stiffness was greater in the scalpel group than in the electrocautery group (P= 0.02). Correlations were found between tissue stiffness and strain energy, between tissue stiffness and bursting force, and between bursting force and strain energy.

Conclusions: While tissue stiffness was greater when a scalpel was used compared to electrocutting to incise the midline abdominal fascia in rats, there was no difference in the bursing force required to disrupt the wound.