Psychiatric assessment of candidates for hand transplantation

An important part of the pretransplant evaluation of candidates for hand transplantation is a psychiatric assessment to formulate psychological benefits and risks of transplantation and determine any appropriate psychosocial interventions to optimize the patient's candidacy for the procedure and prevent psychiatric morbidity. Screening data are presented from 213 individuals who contacted a national referral center for hand surgery regarding hand transplantation, and from the subsequent detailed psychiatric assessments of 9 individuals considering the procedure. Most of the nine patients undergoing intensive psychiatric assessment were assessed as demonstrating an overall favorable profile of psychological benefits and risks. In addition to providing information regarding the psychological experience of patients with amputations and their motivation for hand transplantation, it is hoped this information, as compared with posttransplant outcome data, will help further refine the assessment of candidates for this procedure and possibly other forms of composite tissue allotransplantation.     

Fibronectin in artery subendothelium is important for platelet adhesion

The role of subendothelial fibronectin in platelet interaction with subendothelium was studied. Human umbilical artery subendothelium was exposed to flowing blood containing 111In-labeled platelets in an annular perfusion chamber. Platelet adhesion was determined from the 111In radioactivity on the vessel wall. When perfusions were performed for five minutes at a wall shear rate of 1,800 s-1, platelet adhesion was the same whether normal plasma or fibronectin-free plasma was used. Preincubation of subendothelium with rabbit anti-human fibronectin serum, however, resulted in a marked inhibition of platelet adhesion. Preincubation with normal rabbit serum had no effect. Platelet adhesion was also diminished when the vessel wall was preincubated with anti- fibronectin IgG fraction or F(ab')2 fragment. After the latter preincubations, frozen sections of 4 micron were incubated with fluorescein isothiocyanate-conjugated goat anti-rabbit IgG, F(ab')2 fragment specific. Fluorescence was seen throughout the subendothelium both before and after perfusion. No fluorescence was seen when subendothelium was preincubated with normal rabbit IgG or F(ab')2 or with anti-fibronectin IgG that had been absorbed with purified fibronectin. After absorption of anti-fibronectin IgG with purified fibronectin, the inhibiting effect on platelet adhesion was also no longer present. Preincubation of the vessel wall with anti-fibronectin IgG reduced platelet adhesion significantly at a wall shear rate of 800 s-1. This effect was even greater at 1,800 s-1. At low shear rate (400 s-1), there was no inhibition.     

血管性痴呆发病机制研究进展

血管性痴呆发病率日益增高, 但发病机制不明确, 缺乏有效治疗手段, 因此各方面研究日益受重视, 本文主要对血管性痴呆的危险因素、病理类型、发病机制等方面做一综述.     

Bowel migration in the normal fetus: US detection

Ten fetuses underwent ultrasound scanning at 7-10 weeks gestational (postmenstrual) age. In all cases, an echogenic mass measuring 0.5-1.0 cm was demonstrated within the base of the umbilical cord at its insertion into the fetal abdomen. No area with echogenicity characteristic of the small bowel was identified within the lower part of the fetal abdomen. All fetuses were reexamined 4-12 weeks later, at which time the mass in the umbilical cord was no longer seen, and normal fetal bowel was visualized in the lower abdominal cavity of the fetus. This sequence of findings appears to represent the sonographic demonstration of normal fetal bowel migration early in gestation and should not be confused with defects of the abdominal wall such as omphalocele or gastroschisis.     

Chronically obstructed sinonasal secretions: observations on T1 and T2 shortening

Clinically assessed chronic proteinacious sinonasal secretions usually have long T1 and T2 relaxation times reflecting their high water content. However, in some cases variable combinations of short and long T1 and T2 relaxation times are found. To study the causes of these findings, the magnetic resonance (MR) images of 41 patients with surgically proved, chronically obstructed sinonasal secretions were studied. The relative signal intensities on both T1- and T2-weighted sequences of the sinus specimens were correlated with the gross viscosity of the specimens at surgery. Ten specimens were collected that were not contaminated with either blood or saline. UV spectrophotometric analysis of four of these samples excluded the presence of methemoglobin. Total protein content was determined in five samples, and in vitro T1 and T2 values were measured in one sample. These T1 and T2 relaxation times were accurately predicted with use of a standard pure lysozyme protein solution with the same concentration as the specimen. In addition, the observed T1- and T2-weighted signal intensities on the 41 MR images were predicted from an analysis of pure protein solutions. This study concludes that the primary causes of the variable T1 and T2 relaxation times of chronic sinonasal secretions are the macromolecular protein concentration, the amount of free water, and the specimen viscosity. Furthermore, an orderly and predictable transition of these signal intensities occurs over time.     

Ethical considerations in the early composite tissue allograft experience: a review of the Louisville Ethics Program

This paper reviews the formulation and evolution of the ethical component in one of the earliest clinical composite tissue allograft (CTA) programs, the hand transplantation program in Louisville, Kentucky, USA. The purpose was to derive lessons and define principles to give guidance for future programs and introduction of new CTA. We reviewed the initial ethical considerations, including input from respected ethical scholars, guidelines for innovative procedures transparency in public and professional scrutiny, and compliance with human studies regulations (IRB approval). We found the initial focus on ethics, scholarly input, guidelines for innovative procedures, and human studies protection regulations to be valid. Moreover, we noted the effect of autonomy in subjective, quality-of-life benefits on equipoise and effective risk-benefit analysis in effective informed consent. We found that psychiatric screening and support to be exceptionally valuable in protecting autonomy, suitability for participation, assessing personality organization, and determining compliance ability. We conclude that the program ethical principles were validated. For future CTA programs and procedures, we recommend an ethical emphasis with adherence to high standards and transpire to independence to scrutiny and oversight. We recommend protection of autonomy judgments in equipoise judgment and informed consent. We recommend skilled psychiatric screening and support. We endorse scholarship, scientific accuracy, and data sharing.