Thoracoscopic T2-sympathetic block by clipping--a better and reversible operation for treatment of hyperhidrosis palmaris: experience with 326 cases

Although thoracoscopic sympathectomy or sympathicotomy is the best treatment for hyperhidrosis palmaris, a new approach of clipping only without transection of T2-sympathetic trunk is just as effective. Aside from the guaranteed cure of hyperhidrosis, this new method has fewer complications and has the advantage of recovery of the sympathetic tone in the hands if the procedure is reversed by the removal of the clips. Between March 18 and September 30 of 1996, 326 patients (190 female and 136 male with a mean age of 20.5 years) underwent thoracoscopic T2-sympathetic block by clipping to treat hyperhidrosis. Good results and few complications were noted during follow up six months to one year postoperatively. Five of the 326 patients, all female, had the operation reversed because of intolerable compensatory sweating. Three recovered from the compensatory sweating within two months and had less palmar sweating than before their sympathetic block; the fourth achieved relief of compensatory sweating after nine months, and the fifth reported no improvement.     

Predictors of mortality and the provision of dialysis in patients with acute tubular necrosis. The Auriculin Anaritide Acute Renal Failure Study Group

BACKGROUND: Improvement of angina pectoris symptoms after cholesterol lowering has raised questions as to the underlying mechanisms. METHODS: Rabbit experiment: We compared arterial blood samples from New Zealand White cholesterol-supplemented rabbits (n = 6) with nonsupplemented rabbit samples (n = 4) in a closed-loop circulation diffusion system. The pH and partial pressures of oxygen (pO2) and carbon dioxide (pCO2) were measured continuously. The samples were first oxygen (O2) saturated (pO2, 160 mm Hg; pCO2, 4 mm Hg) and then desaturated in 100% nitrogen. Cholesterol levels were determined in whole blood, plasma (P Chol), red blood cells (RBCs), and RBC membranes. Human experiment: We exposed quadruple desaturated venous blood samples (n = 4) with P Chol levels of 87 to 400 mg/dL in a gas exchanger to capillary gas conditions (pO2, 23 mm Hg; pCO2, 46 mm Hg). After 15 minutes we performed blood gas analyses and compared our results to baseline values. RESULTS: In the rabbit experiment the cholesterol-supplemented group as compared to the control group showed higher plasma pO2 levels during the saturation phase and lower plasma pO2 levels during the desaturation phase. It also had a markedly increased RBC membrane cholesterol content: 121 +/- 3 (standard error of the mean [SEM]) mg/dL versus 22 +/- 1.7 mg/dL in the control group (P < .05). This barrier to RBC membrane O2 diffusion caused delayed O2 entry into the RBCs during saturation, with a higher plasma pO2, and delayed O2 release from the RBCs during desaturation, with a lower plasma pO2. In the human experiment the P Chol level was inversely correlated with the percentage change of O2 content in milliliters of O2 per deciliter of blood (P < .05). CONCLUSIONS: Increased RBC membrane cholesterol in hypercholesterolemia appears to decrease the transmembrane O2 diffusion rate.     

Can routinely combined analysis of glucose and lactate in vitreous humour be useful in current forensic practice?

An ongoing goal of aesthetic surgery is a reduction in complications and an improvement in reproducibility and speed. Balloon dissector devices have been used in other areas of surgery to achieve these goals. This report presents early clinical experience using a balloon dissector to elevate the skin flap in facialplasty. The first step in the technique is the creation of a tunnel from a small preauricular incision toward the oral commissure using scissors dissection. The balloon device is inserted into this tunnel and inflated. Unrolling the device elevates the skin flap in the cheek and neck area. Retroauricular dissection and final adjustment of flap size and shape is completed sharply. Subsequent superficial musculoaponeurotic system flap development, skin redraping, and closure is performed in a conventional fashion after customary facialplasty incisions are made. Comparison of complications, postoperative drainage, and time required for dissection and for hemostasis was made between a balloon-dissected side and a conventionally dissected side in 10 patients undergoing facialplasty. Ten additional patients were treated with balloon dissection bilaterally. Patients ranged in age from 45 to 73 years. Mean balloon dissection time was 1.4 minutes (range, 0.75-4 minutes). This produced an even flap thickness in the correct plane with few if any bleeding points. Mean total dissection time on the balloon side was significantly shorter-13.6 minutes-compared with 27.8 minutes (p < 0.003) on the conventional side. Mean difference in time to hemostasis between conventional and balloon sides was 3.8 minutes (p < 0.001). Mean total postoperative drainage (all drains removed at 24 hours) was 13.8 cc on the balloon side and 18.8 cc on the conventional side (not significant, p=0.08). Less ecchymosis and swelling was observed on the balloon side compared with the scissors-dissected side. There were no skin losses, hematomas, infections, or nerve injuries on either side. Appearance of skin redraping was comparable on each side in all patients. Balloon dissection represents a promising alternative means of creating rapid, reproducible skin flap elevation in facialplasty, and is associated with a minimum of bleeding, ecchymosis, and swelling.     

Source of respiratory drive during periodic breathing in lambs

In order to investigate the mechanisms underlying periodic breathing (PB), we studied the initiation of breathing after passive hyperventilation in 14 anaesthetised 10-20 day old lambs. Eight of the lambs exhibited PB following post-hyperventilation apnea (PHA), with an epoch duration of 82.4 +/- 14.2 sec (mean +/- SEM), a cycle duration of 9.7 +/- 0.7 sec and a ratio of ventilatory duration to apnea duration (V-A ratio) of 1.24 +/- 0.32. The remaining lambs showed stable breathing patterns following PHA. The ventilatory response to isocapnic hypoxia was significantly greater in the group that had PB (-7.2 +/- 1.0 ml min-1% Sao2-1 kg-1) than in the animals that did not (-2.5 +/- 1.0 ml min-1%Sao2-1 kg-1). Using experimentally determined ventilatory response curves to O2 and CO2 we calculated that the swings in Sao2 and Paco2 during PB generated chemical drive that accounted for only 16.2% of the ventilatory oscillations observed during PB. Much of the remaining drive appeared to originate in the 'switch-on' characteristics of the respiratory controller, in lambs that exhibited periodic breathing, when breathing began after PHA ventilation jumped abruptly from zero to 55.1% of the eupneic ventilation. The magnitude of this jump in ventilation accounted for 51.9% of the amplitude of ventilatory oscillations that occur during PB. We speculate that this previously unrecognised feature of the respiratory controller, together with an elevated sensitivity to hypoxaemia, play crucial roles in generating PB in the infant.     

A low rate of reinfection following effective therapy against Helicobacter pylori in a developing nation (China)

Ascorbate peroxidase (APX) is a hydrogen peroxide-scavenging peroxidase which uses ascorbate (AsA) as the specific electron donor. APX has not been isolated in mammals. Ocular tissue contains AsA at high concentrations, and we detected APX activity in bovine retinal pigment epithelium (RPE) and choroid. We purified APX from bovine RPE and choroid by four chromatographic steps. The purified APX was a monomeric hemoprotein with a molecular mass of 43 kDa. The amino acid sequence of the amino-terminal region of the purified APX showed a high degree of homology to that of plants. The primary product of the APX reaction was identified as the monodehydroascorbate radical. The APX showed high specificity for AsA as an electron donor. This is the first isolation and characterization of APX from mammals, and its role in the protection against active species of oxygen in ocular tissue is discussed.     

External and internal calibration of the MHC class I-specific receptor Ly49A on murine natural killer cells

Expression of the H-2Dd-specific inhibitory receptor Ly49A on murine NK cells is subject to MHC class I-dependent modulation in vivo. As a result, NK cells in H-2Dd-transgenic mice express low cell surface levels of Ly49A, whereas NK cells from nontransgenic C57BL/6 (B6) mice express high levels. The purpose of this study was to assess the role of MHC class I molecules on the NK cell itself vs those on surrounding cells in this calibration and to test whether the Ly49A levels are subject to regulation in mature NK cells also. Analysis of transgenic mice with mosaic expression of an H-2Dd/Ld transgene showed that MHC class I molecules on surrounding cells (external ligands) and on the NK cell itself (internal ligands) played distinct roles in the determination of Ly49A levels. External ligands were involved in down-regulation of Ly49A levels in vivo, whereas internal ligands kept the down-regulated levels of Ly49A low upon NK cell activation in vitro. Furthermore, in an experimental system based on adoptive transfer of spleen cells, receptor down-regulation of Ly49A occurred as a rapid adaptation process in mature NK cells after interaction with the H-2Dd ligand in vivo. This suggests that Ly49 levels are not fixed but can be changed in mature NK cells when they are exposed to a changed MHC class I environment.     

The number of self-incompatibility alleles in a finite, subdivided population

The actual and effective number of gametophytic self-incompatibility alleles maintained at mutation-drift-selection equilibrium in a finite population subdivided as in the island model is investigated by stochastic simulations. The existing theory founded by Wright predicts that for a given population size the number of alleles maintained increases monotonically with decreasing migration as is the case for neutral alleles. The simulation results here show that this is not true. At migration rates above Nm = 0.01-0.1, the actual and effective number of alleles is lower than for an undivided population with the same number of individuals, and, contrary to Wright's theoretical expectation, the number of alleles is not much higher than for an undivided population unless Nm < 0.001. The same pattern is observed in a model where the alleles display symmetrical overdominant selection. This broadens the applicability of the results to include proposed models for the major histocompatibility (MHC) loci. For a subdivided population over a large range of migration rates, it appears that the number of self-incompatibility alleles (or MHC-alleles) observed can provide a rough estimate of the total number of individuals in the population but it underestimates the neutral effective size of the subdivided population.