Israel Medical Association Journal

Background: Multiple factors are involved in the pathogenesis of hypertension in the obese individual.

Objective: To evaluate the role of a decrease in sympathetically mediated thermogenesis and the effect of the correlation between the plasma leptin and daily urinary nitric oxide levels on obesity-related hypertension.

Methods: We evaluated three groups: 25 obese hypertensive patients (age 45.7±1.37 years, body mass index 34.2±1.35 kg/m², systolic/diastolic blood pressure 155±2.9/105±1.3, mean arterial pressure 122±1.50 mmHg); 21 obese normotensive patients (age 39.6±1.72, BMI[1] 31.3±0.76, SBP/DBP[2] 124±2.1/85.4±1.8, MAP[3] 98.2±1.80); and 17 lean normotensive subjects (age 38.1±2.16, BMI 22.1±0.28, SBP/DBP 117±1.7/76.8±1.5, MAP 90.1±1.50). We determined basal resting metabolic rates, plasma insulin (radioimmunoassay), norepinephrine (high performance liquid chromatography) in all subjects. Thereafter, 14 obese hypertensives underwent a weight reduction diet. At weeks 6 (n=14) and 14 (n=10) of the diet the above determinations were repeated. Plasma leptin (enzyme-linked immunosorbent assay) and UNOx[4] (spectrophotometry) were assayed in 17 obese hypertensives and 17 obese normotensives, and in 19 obese hypertensives versus 11 obese normotensives, respectively.

Results: Obese hypertensive patients had significantly higher basal RMR[5] and plasma NE[6] levels. Insulin levels were lower in the lean group, with no difference between the hypertensive and normotensive obese groups. At weeks 6 and 14, BMI was significantly lower, as were insulin and NE levels. RMR decreased to values of normotensive subjects. MAP normalized but remained significantly higher than that of obese normotensives. Leptin blood levels and the leptin/UNOx ratio were significantly higher in the obese hypertensive compared to the obese normotensive patients. Both these parameters were strongly correlated to BMI, MAP⁵, RMR, and plasma NE and insulin .Obese hypertensive patients excreted less urinary NO metabolites. A strong correlation was found between MAP and the leptin/UNOx ratio.  

Conclusions: A reduction of sympathetically mediated thermogenesis, as reflected by RMR, results in normalization of obesity-related hypertension. In contrast, insulin does not seem to play a major role in the pathogenesis of hypertension associated with obesity. Increased leptin levels in conjunction with decreased NO production in the presence of enhanced sympathetic activity may contribute to blood pressure elevation in the obese.

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[1] BMI = body mass index

[2] SBP/DBP = systolic blood pressure/diastolic blood pressure

[3] MAP = mean arterial pressure

[4] UNOx = urinary nitric oxide

[5] RMR – resting metabolic rate

[6] NE = norepinephrine

Background: Femoral hip fractures are a common occurrence in the elderly. Of the various fracture patterns, intertrochanteric injuries have the lowest rate of complications. Case reports of ensuing subcapital fracture have all been linked to incorrect placement of fixation devices or to osteomyelitis, while cases of avascular necrosis have only been reported rarely in the literature and are considered to occur at the rare rate of 0.8%.

Objectives: To check the incidence and outcome of AVN[1] in intertrochanteric hip fractures.

Methods and Results: In a retrospective analysis of patients who had surgical treatment for intertrochanteric fractures, 10 patients (0.5%) underwent dynamic hip screw fixation for intertrochanteric fractures and subsequently developed painful AVN as their primary presentation. Three of these patients were also found to have subcapital fractures. On revision of the primary fixation no fault was found with nail placement.

Conclusions: The reported rate of AVN may be understated since many patients have limiting factors that prevent them from consulting a physician when in pain, and one-third of these patients die within 2 years. Therefore, we suggest that hip pain following fixation of an intertrochanteric fracture should prompt the clinician to consider the rare possibility of AVN or subcapital fracture.

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[1] AV = avascular necrosis

The complex genetic nature of many common diseases makes the identification of the genes that predispose to these ailments a difficult task. In this review we discuss the elements that contribute to the complexity of polygenic diseases and describe an experimental strategy for disease-related gene discovery that attempts to overcome these factors. This strategy involves a population-based case-control paradigm and makes use of a highly informative, homogeneous founder population, many of whose members presently reside in Israel. The properties of single nucleotide polymorphisms, which are presently the markers of choice, are discussed, and the technologies that are currently available for SNP[1] genotyping are briefly presented.

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[1] SNP = single nucleotide polymorphism

This review summarizes the clinical, metabolic and genetic characteristics of early-onset type 2 diabetes in Mexico. Early-onset type 2 diabetes is both a clinical challenge and a public health problem. It is calculated that almost 300,000 Mexican diabetics are diagnosed between the ages of 20 and 40. The large Mexican family structure and the high prevalence of the disease provide a unique opportunity to identify the genes and the metabolic abnormalities involved in this form of the disease. In a hospital-based population, our group found that insulin deficiency was the main defect in this form of diabetes. Mutations in the HNF-1α or HNF-4α genes or autoimmunity to the beta cell were found in a small proportion of cases, leaving unexplained the majority of cases. Also discussed are the epidemiologic and therapeutic implications of early-onset type 2 diabetes, and the possible role of genetic testing for prevention.

Background: As air travel increases and the number of commercial and non-commercial flights rises so does the number of aircraft accidents. The improved safety standards of the aviation industry result in a growing number of survivors of aircraft crashes, but there are no management guidelines for the treatment of aircraft crash survivors.

Objectives: To present our experience in treating five survivors of a light aircraft crash that occurred in August 1995 near Jerusalem.

Results: All five survivors sustained vertebral column injuries, which was the only injury in most of the survivors. We discuss the mechanism of injury.

Conclusions: Investigation of injuries’ pattern in survivors of aircraft crash is important for establishing management protocols in trauma centers.
 

Background: Genetic factors have been shown to play a major role in the development of peak bone mass, with hereditability accounting for about 50-85% of the variance in bone mass. Numerous candidate genes were proposed to be involved in osteoporosis, but the precise genes and their relative contribution remain unknown.

Objectives: To gain insight into the genetic basis of idiopathic low bone mineral density in Israeli patients by analyzing the impact of two candidate genes: polymorphism of the vitamin D receptor gene and polymorphism A986s in the calcium-sensing receptor gene.

Methods: We analyzed 86 Jewish Israeli patients with LBMD[1]: 38 premenopausal women and 48 men, and compared the allelic pattern distribution with that of the general population (126 men and 112 women). Genotyping of the VDR[2] gene was performed in three polymorphic sites using restriction enzymes, and allelic analysis of A986s polymorphism in the CaSR[3] gene was performed using the denaturing gradient gel electrophoresis technique.  

Reaults: In LBMD women the distributions of VDR alleres in Apal polymorphism were AA=7/28, Aa=16/28 and aa=5/28; in TaqI polymorphism TT=10/31, Tt=16/31 and tt=5/31; and in BsmI polymorphism BB=7/32, Bb=14/32 and 11/32. In LBMD men the distributions were AA=17/39, Aa=21/39 and aa=1/39; in TaqI polymorphism TT=12/42, Tt=23/42 and tt=7/42; and in BsmI polymorphism BB=12/41 Bb=18/41 and bb=11/41. The distributions of all these polymorphisms in the control groups were not significantly different. Adjusting for the independent age and gender parameters confirmed that these three polymorphisms of the VDR gene did not have a significant effect on bone mineral density. Thirty percent (24/79) of LBMD patients of either sex displayed heterozygosity of the CaSR A986s polymorphism, compared with 40 of 203 controls (19.7%) (P=0.059). Adjusting for age and gender in these patients revealed a significant difference in the femoral neck BMD[4] between homozygotes and heterozygotes (P=0.002). The age at menarche of the LBMD women was found to predict 61% of the variance of femoral neck BMD.

Conclusions: In Israeli Jewish men and premenopausal women VDR gene alleles do not seem to be associated with lower lumbar spine or femoral neck BMD. A trend towards heterozygosity for a CaSR polymorphism missense mutation was noted in the LBMD patients. Age at menarche in the LBMD women was found to be an important predictor of BMD. A significant difference was found between LBMD women and healthy control women towards heterozygosity for a CaSR polymorphism, as well between homozygotes and heterozygotes for a CaSR polymorphism in BMD. The significance of these findings and their applicability to a larger population awaits further studies.

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Background: Open reduction and internal fixation are the current trends of treatment for comminuted calcaneal fractures. Assessing treatment results is often difficult due to discrepancy between objective parameters such as range of movement, and subjective results such as pain.

Objectives: To test the reliability of footprint analysis as an adjuvant method of postoperative assessment of patients who sustained calcaneal fractures.

Methods: Dynamic and static footprint analysis was used as an adjuvant method to objectively assess operative results. This method is simple and is independent of the patient’s initiatives. This modality was used in 22 patients followed-up 9–90 months postoperatively.

Results: We found a good correlation between footprint analysis and objective and subjective parameters of results expressed by the American Orthopedic Foot and Ankle Society hind foot score. In certain cases, this method can be used to distinguish between uncorrelated parameter results, such as malingering, and workmens’ compensation claims.

Conclusion: We recommend the use of this simple, non-invasive objective test as an additional method to assess the results of ankle and foot surgery treatment.