A new polymorphic restriction site in the human 11 beta-hydroxysteroid dehydrogenase type 2 gene

The 11 beta-hydroxysteroid dehydrogenase type II enzyme (11 beta HSD2) inactivates glucocorticoids in the kidney and thus prevents glucocorticoids from occupying the non-selective mineralocorticoid receptor in epithelial tissues. Mutations in the HSD11B2 gene have been found to cause the syndrome of apparent mineralocorticoid excess, a rare autosomal recessive disease characterized by severe hypertension. Thus, this locus could also be an ideal candidate involved in the etiology of primary hypertension. We identified a polymorphism in exon 3 characterized by a GAG to GAA transition at codon 178, with the loss of an Alu I restriction site and analysed it in an association study using end-stage renal disease patients, diabetic or essential hypertensive patients and control subjects. Two-hundred and eighty nine subjects and patients were analysed; the genotype was determined by amplification of genomic DNA and subsequent digestion with Alu I restriction enzyme. The prevalence of the Alu I allele was 8.6% in healthy control subjects (n = 116). This prevalence was lower (chi 2 P = 0.035 vs. controls) than the 18.0% in a group of renal transplant patients (n = 61). The corresponding values for patients with diabetes mellitus (n = 25), hypertension (n = 41) and patients on dialysis (n = 46) were 4.0%, 4.8% and 4.3%, respectively. There was no correlation between blood pressure and the marker in non-ESRD subjects. These data indicate the presence of a polymorphic marker in exon 3 of the HSD11B2 gene; this marker is associated with end-stage renal disease but not with essential hypertension in humans.     

Thermodynamic properties of regular interstitial solutions

The thermodynamics of interstitial solutions are conceptually different from the thermodynamics of substitutional solutions because the state corresponding to pure solute is experimentally inaccessible for the interstitial solution. The thermodynamic functions for the ideal and regular interstitial solutions are given and expressions for the critical point, spinodal curve, solvus, two solid-phase equilibrium, and specific heat are derived for the regular interstitial solution.     

Thin needle cholangiography: experience with 50 patients

Thin needle cholangiography (TNC) was performed in 50 patients with obstructive jaundice or jaundice of obscure origin. The purpose of this study was to assess the diagnostic accuracy and safety of this procedure. TNC was performed by the technique described by Redeker et al. using the Chiba needle (JAMA 231:386, 1975). Obstructed ducts were successfully demonstrated in 100% of cases (29/29). Non-obstructed ducts were opacified in 12/21 (57%). Overall success was 82% (41/50). Two septic complications occurred. It is concluded that 1) TNC is a highly reliable, easy to perform and safe procedure in the evaluation of the jaundiced patient; 2) Accurate demonstration of the biliary anatomy by TNC provided important information which often in (10/50 = 20%) led to a change in diagnosis, avoidance of unnecessary procedures, and shortening of hospitalization; 3) Failure to visualize patients with non-dilated biliary ducts occurred with advanced chronic liver disease or fatty liver.     

Behavioral change and public attitudes toward public health

One hundred patients suffering from recurrent acute tonsillitis were studied. One hundred tonsils were cultured. Surface bacteria were compared to deep bacteria. In 48 per cent of the cases a different pathogen was cultured from the interior of the tonsil as compared to the surface culture. This fact may explain recurrence of tonsillitis and makes the reliability of the conventional tonsillar culture questionable. Surgical extirpation of the tonsils seems to be the only treatment since deep bacteria remain unidentified and resist the antibiotic therapy that may affect only the surface microflora.     

Reduction of central nervous system reperfusion injury in rabbits using doxycycline treatment

BACKGROUND AND PURPOSE: Activated leukocytes appear to potentiate central nervous system reperfusion injury, and agents that block leukocyte adhesion have shown neuroprotective efficacy in experimental models. Doxycycline, a tetracycline antibiotic, inhibits leukocyte function in vitro, presumably through divalent cation binding. We used a model of focal central nervous system reperfusion injury to determine the efficacy of doxycycline treatment in preserving neurological function. METHODS: Rabbits randomly received 10 mg/kg i.v. doxycycline 30 minutes before ischemia (pretreatment group) or 45 minutes after ischemia (posttreatment group) or received phosphate-buffered saline vehicle (control group) followed by 10 mg/kg q 8 hours times two. The average length of reversible spinal cord ischemia required to produce paraplegia (P50) at 18 hours was calculated for each group. RESULTS: For the control group (n = 13), the P50 was 22.8 +/- 2.2 minutes; for the pretreatment group (n = 14), 35.5 +/- 2.4 minutes (P < .01; t = 3.8); and for the posttreatment group (n = 13), 31.4 +/- 4.2 minutes (not significant; t = 1.6). Doxycycline also attenuated postischemic decreases in vivo leukocyte counts and inhibited in vitro leukocyte adhesion. Therapeutic doxycycline levels at 24 hours were confirmed in the plasma and spinal cord. CONCLUSIONS: This significant protective effect suggests that doxycycline, a safe and readily available agent, may play a role in reducing clinical central nervous system reperfusion injury.     

A fully plastic microcracking model for transgranular stress-corrosion cracking in planar-slip materials

It has been confirmed that transgranular stress-corrosion cracking (T-SCC) can be discontinuous under slow strain-rate testing, at least for materials which deform by planar slip(i.e., those which have low stacking-fault energy). Interpretation of the load and current transients shows that the crack velocity is on the order of 100 μm/s, depending on the environment — too slow to be explained by a running brittle crack and too fast to be explained by Faradaic dissolution. Support of such an interpretation is given by the agreement between predictions of crack area by mechanical analysis of the load transients (taking into account the elastic displacement of the load train and of the specimen because of both the changing load and the crack advance) and the predictions from analysis of the current transients, as well as the agreement of such predictions with the resulting crack-advance distance determined from fractography. Such agreement follows if the assumption is made that cracking is fully plastic, that is, if deformation accompanies cracking such that the nominal stress on the uncracked cross section is maintained at the flow stress. The significance of this finding with respect to a corrosion-assisted microcleavage model is discussed.