Skin necrosis complicating mallet finger splinting and vascularity of the distal interphalangeal joint overlying skin

Two patients are reported with full-thickness skin necrosis over the dorsum of the distal interphalangeal (DIP) joints after dorsal splint immobilization in hyperextension to treat acute mallet finger. An investigation was carried out to study the relationship of hyperextension to the dorsal circulation of the DIP joint. In 66 digits, the average degree of DIP joint hyperextension at which the skin blanches was 50% of the total passive hyperextension. It is recommended, therefore, when the DIP joint is immobilized to treat acute mallet finger, the degree at which the dorsal skin begins to blanch must be determined, and the amount of hyperextension should not exceed that degree. Excessive localized pressure to the dorsal skin should be avoided by adjusting the angle of the dorsal splint.     

Ärztliche Fehleroffenbarung – Strafrechtliche Strategien für postinvasive Arzt-Patientengespräche

Ohne Zusammenfassung     

Control of respiration by the hypothalamus and by feedback from contracting muscles in cats

Central command and feedback from contracting muscles are two mechanisms which are thought to control the respiratory and cardiovascular systems during exercise. In this study, we compared the individual and combined responses to activation of central command and to muscular contraction in anesthetized cats. Continuous electrical stimulation of the subthalamic locomotor region (STLR) was used to simulate central command (Eldridge et al., 1985). Static (tetanic) contraction of hindlimb muscles was produced by stimulating the cut peripheral ends of the L7-S1 ventral roots. Despite similar increases in arterial pressure, STLR stimulation caused larger increases in cardiac frequency and respiration than that evoked by muscular contraction. When performed during muscular contraction, STLR still caused large increases in respiration, arterial pressure and cardiac frequency. In contrast, muscular contraction when induced during STLR stimulation caused only small increases in respiration and modest changes in arterial pressure and cardiac frequency. These results suggest that central command and feedback from contracting muscles exert different respiratory and cardiovascular effects when activated simultaneously than when activated individually. In addition, central command, as activated by STLR stimulation, predominates over the responses caused by muscular contraction.     

Exchange-transfusion with pyridoxalated polymerized hemoglobin: effects on liver PO2

To examine the efficacy of modified stroma-free hemoglobin in maintaining liver PO2, rats were exchange-transfused to hematocrit 10% using pyridoxalated polymerized hemoglobin (plp-polyHb, 10-12 g/dl) prepared from crystalline Hb. Following hemodilution, plasma Hb was 7.4 g/dl, and rats were normotensive. Mean liver PO2 was 3.4 vs 23.3 mm Hg in sham-exchanged controls. Other rats, hemodiluted similarly with 6% albumin or hydroxyethylstarch, were hypotensive and died. At 24 hours plasma Hb was 2.0 g/dl, indicating an intravascular half-life of approximately 16 hours. Hepatic PO2 was 12.4 vs 26.8 mm Hg in nonhemodiluted controls. Data provided by clearance of low-dose indocyanine green suggested reduced plasma volume and depressed liver blood flow. Scattered foci of midzonal hypoxic damage were observed in liver lobules. The basis for hypoxic injury is considered to be due in part to the acute restriction of oxygen supply induced by exchange-transfusion with plp-polyHb. The rate of loss of intravascular hemoglobin and diminished plasma volume could have contributed to oxygen insufficiency as well. Endotoxin present in the plp-polyHb was not a factor.     

Capacity related characteristics of Glyco-Gel affinity chromatographic support

We examined capacity related properties of "Glyco-Gel" (Pierce), a boronate agarose gel for separating and measuring glycated proteins by affinity chromatography. Our data indicate linear capacity to as much as 20 mg as applied hemoglobin or almost 10 mg as bound hemoglobin and 26 mg as applied serum proteins or a minimum of 2.5 mg as bound serum protein for each mL of gel. The capacity and affinity of the support for glycated proteins becomes optimum only after four regeneration cycles. The support matrix appears to have a small concentration of nonspecific binding sites equivalent to 0.09 to 0.18 mg as serum protein for each mL of gel. These sites do not bind hemoglobin. They lead to an overestimation of glycated protein that can cause large errors when the proportion of glycated protein is determined with small column loads. If near capacity loads are applied, the samples must be dialyzed or diluted to avoid decreased analytical recovery resulting from competitive and eluting properties of endogenous sugars.     

Neuron-specific enolase. Assessment by ELISA in patients with small cell carcinoma of the lung

Measurement of tissue-specific enolase isoenzymes may be of assistance in identifying small cell carcinomas of the lung and in distinguishing them from other pulmonary tumors. Enolase (E.C. 4.2.1.11) is a dimeric enzyme composed of various permutations of three immunologically distinct subunits alpha, beta, and gamma. Five isoenzymes alpha alpha, beta beta, gamma gamma, alpha beta, and alpha gamma have been identified. Immunohistochemical studies using antibodies to the gamma subunit have localized alpha gamma and gamma gamma specifically within neuronal and neuroendocrine tissues. Because of this limited distribution, neuron-specific enolase (NSE) can function as a biochemical marker for neuroendocrine tumors. The authors developed an enzyme-linked immunosorbent assay (ELISA) using the double antibody sandwich method. The sandwich is composed of rabbit antirat enolase that cross-reacts to the human gamma monomer, making the test specific for the gamma gamma isoenzyme. The avidin-biotin-peroxidase complex system is used to provide increased assay sensitivity. Serum samples from patients with histologically diagnosed small cell carcinoma have concentration of NSE 20- to 30-fold greater than that found in normal serum. Studies were conducted on patients with a variety of malignant pulmonary lesions and compared with controls to determine the value of NSE as a tumor marker.