Modified stirrups for dorsal lithotomy positioning

The modified dorsal lithotomy position is excellent for radical pelvic operations. Use of modified Krauss arm supports as stirrups, along with pneumatic devices that intermittently compress the legs, significantly reduces postoperative morbidity in patients who undergo operations in this position.     

Interaction between thiol-modifying agents and P1075, a KATP channel opener, in rat isolated aorta

In vascular smooth muscle, openers of ATP-dependent potassium channels (K _ATP channels), such as P1075 (N-cyano-N’-(1,1-dimethylpropyl)-N’’-3-pyridylguanidine), produce relaxation. In this study we have investigated the effects of thiol-modifying agents on the binding of P1075 and on the ⁸⁶Rb⁺ efflux stimulating and vasorelaxant effects of the opener in rat aortic rings. The increase in ⁸⁶Rb⁺ efflux induced by P1075 was taken as a qualitative measure of K⁺ channel opening. The hydrophilic SH-group-oxidizing substance, thimerosal (1 to 100μM), abolished specific binding of [³H]-P1075 with an IC₅₀ value of 7.6±1.2μM; at 30μM, the half time for inhibition was 38min. Two other thiol-oxidizing agents, PMB (4-hydroxy-mercuribenzoic acid) and DTBNP (2,2’-dithio-bis(5-nitropyridine)), inhibited binding up to 86% and 44%, respectively. The disulphide bond reducing substance, DTT (1,4-dithiothreitol, 0.1 to 1mM), reduced [³H]-P1075 binding by up to 20% and partially reversed the inhibitory effect of thimerosal. In ⁸⁶Rb⁺ efflux experiments, thimerosal (3 to 100μM) concentration-dependently increased basal efflux but inhibited P1075-stimulated tracer efflux with an IC₅₀ value of 7±1μM. The inhibitory effect occurred with a half-time of approximately 8min and was essentially reversed by DTT. In rings precontracted with noradrenaline, thimerosal inhibited the vasorelaxant effect in a noncompetitive manner, shifting the concentration-relaxation curves to the right and reducing maximum relaxation.The data show that oxidation of thiol groups interferes with the binding of the K _ATP channel opener, P1075; concomitantly, the ⁸⁶Rb⁺ efflux stimulating and the vasorelaxant effects are inhibited. Reduction of disulphide bonds by DTT has only minor effects on the action of P1075. Collectively, the results suggest that intact thiol groups are essential for the functioning of the K_ATP channel in rat aorta. The different kinetics governing the inhibition of opener binding and of opener-stimulated ⁸⁶Rb⁺ efflux suggest that the SH-groups involved in the two processes differ in their accessibility to thimerosal and/or in their reactivity. Received: 7 April / Accepted: 9 July 1997     

Glycine transporter I inhibitor, N-methylglycine (sarcosine), added to antipsychotics for the treatment of schizophrenia.

BACKGROUND: Hypofunction of N-methyl-D-aspartate glutamate receptor had been implicated in the pathophysiology of schizophrenia. Treatment with D-serine or glycine, endogenous full agonists of the glycine site of N-methyl-D-aspartate receptor, or D-cycloserine, a partial agonist, improve the symptoms of schizophrenia. N-methylglycine (sarcosine) is an endogenous antagonist of glycine transporter-1, which potentiates glycine's action on N-methyl-D-aspartate glycine site and can have beneficial effects on schizophrenia. METHODS: Thirty-eight schizophrenic patients were enrolled in a 6-week double-blind, placebo-controlled trial of sarcosine (2 g/d), which was added to their stable antipsychotic regimens. Twenty of them received risperidone. Measures of clinical efficacy and side effects were determined every other week. RESULTS: Patient who received sarcosine treatment revealed significant improvements in their positive, negative, cognitive, and general psychiatric symptoms. Similar therapeutic effects were observed when only risperidone-treated patients were analyzed. Sarcosine was well-tolerated, and no significant side effect was noted. CONCLUSIONS: Sarcosine treatment can benefit schizophrenic patients treated by antipsychotics including risperidone. The significant improvement with the sarcosine further supports the hypothesis of N-methyl-D-aspartate receptor hypofunction in schizophrenia. Glycine transporter-1 is a novel target for the pharmacotherapy to enhance N-methyl-D-aspartate function.     

Early and medium-term results after modified Fontan operation in adults.

OBJECTIVE: Single ventricle palliation is rarely performed in adults and the results are less optimal than in children. In this article we analyze our experience with the modified Fontan operation in this age group. METHODS: Data of 15 consecutive patients with single ventricle with a mean age of 26 (range 16-38) years, who underwent Fontan operation between 3/92 and 1/2000 were retrospectively analyzed. Five patients had previously had an aortopulmonary shunt in childhood and two patients had previously received a bi-directional cavopulmonary shunt as adults. Eleven patients were preoperatively in NYHA class III and four in class II. The main factors for the selection of the patients before surgery were well-developed pulmonary arteries with lower lobe index 120+30 mm/m(2), pulmonary artery pressure <18 mmHg, good cardiac function and enddiastolic systemic ventricular pressure <12 mmHg. The lateral tunnel Fontan operation (LTFO) was performed in ten patients and extracardiac Fontan operation (ECFO) in five. A fenestration 4-5 mm in size was constructed in all patients with LTFO and in three of five patients with ECFO. RESULTS: There was one intraoperative and one late death (total mortality 13%). The mean extubation time and hospital stay were 24 h and 21 days, respectively. Severe postoperative complications were observed in three patients (20%). Two LTFO patients out of a total of eight patients (53%) with perioperative arrhythmias received a permanent pacemaker due to bradyarrhythmia. During the median follow-up of 5.0 (range 2.3-10.1) years, four patients developed arrhythmias; one of them had new onset bradyarrhythmia after LTFO and required permanent pacemaker implantation. The median postoperative oxygen saturation was 93% (range 90-98%). NYHA class improved significantly in 12 survivors. Cardiac catheterization (0.5-4 years postoperatively, n=12) showed excellent Fontan hemodynamics in all patients. CONCLUSIONS: The modified Fontan operation can be performed in adults with acceptable early and midterm mortality and morbidity and leads to either complete or marked relief of cyanosis and enhanced exercise tolerance in all survivors. Postoperative arrhythmias are one of the main drawbacks but the incidence of arrhythmias after ECFO seems to be lower. The long-term follow-up has yet to be established.     

Atypical onset of symptoms in Huntington disease: severe cognitive decline preceding chorea or other motor manifestations.

OBJECTIVE: To describe the onset of Huntington disease (HD) in a patient with atypical progression of symptoms. BACKGROUND: The authors report the case of a 39-year-old man with severe cognitive impairment and diffuse cortical atrophy before the onset of motor manifestations or symptoms of an extrapyramidal movement disorder. METHOD: Clinical examinations, neuropsychologic assessments, magnetic resonance imaging, electroencephalogram, and genetic testing were conducted. RESULTS AND CONCLUSIONS: Although HD was eventually confirmed through genetic testing, chorea was not part of the clinical picture until well after the patient had developed a frank dementia, with a decline in global intellectual functioning, memory deficits, slowed information processing speed, and executive dysfunction. This case indicates HD may present with atypical clinical features in the early course of the disease, and warrants diagnostic consideration in patients with early dementia of unknown etiology.     

Quantitative Magnetic Resonance Imaging of Human Brain Development: Ages 4-18

Brain magnetic resonance images (MRI) of 104 healthy childrenand adolescents, aged 4–18, showed significant effectsof age and gender on brain morphometry. Males had larger cerebral(9%) and cerebellar (8%) volumes (P < 0.0001 and P = 0.008.respectively), which remained significant even after correctionfor height and weight After adjusting for cerebral size, theputamen and globus pallidus remained larger in males, whilerelative caudate size was larger in females. Neither cerebralnor cerebellar volume changed significantly across this agerange. Lateral ventricular volume increased significantly inmales (trend for females), with males showing an increase inslope after age 11. In males only, caudate and putamen decreasedwith age (P = 0.007 and 0.05, respectively). The left lateralventricles and putamen were significantly greater than the rightP = 0.01 and 0.0001, respectively). In contrast, the cerebralhemispheres and caudate showed a highly consistent right greater-than-leftasymmetry (P < 0.0001 for both). All volumes demonstrateda high degree of variability. These findings highlight gender-specificmaturational changes of the developing brain and the need forlarge gender-matched samples in pediatric neuropsychiatric studies.