Shoulder Position During Magnetic Resonance Arthrogram Significantly Affects Capsular Measurements

PurposeTo determine whether change in shoulder position between internal rotation (IR) and external rotation (ER) during magnetic resonance arthrography (MRA) affects previously defined capsular measurements and to determine the utility of rotation in the diagnosis of instability.MethodsA retrospective study was conducted of patients who received a shoulder MRA with humeral IR and ER views. Patients with an arthroscopically confirmed diagnosis of instability and those with clinically stable shoulders, no history of instability, and no MRA findings of instability were identified and compared. Humeral rotation, glenoid retroversion, humeral head subluxation, capsular length, and capsular area using axial sequences of IR and ER views were recorded. Analysis compared IR, ER, and Δ capsular measurements between groups using independent t tests and univariate and multivariate regression.ResultsThirty-one subjects who were diagnosed with instability were included, along with 28 control subjects. Capsular length, capsular area, and humeral subluxations were significantly greater with ER compared with IR views (P < .001, P < .001, P < .001). Patients with instability displayed greater ER capsular length (P = .0006) and ER capsular area (P = .005) relative to controls. Multivariate logistic regression identified age, weight, sex, ER capsular length, and retroversion to be significant predictors of instability. ER capsular length independently predicts instability with 86% sensitivity and 84% specificity. Interobserver reliability using the intraclass correlation coefficient was rated good or excellent on all measurements.ConclusionVariance in humeral rotation during shoulder MRA significantly affects capsular measurements. Rotational views increase the utility of capsular measurements when assessing for instability, particularly capsular length and capsular area. The implementation of ER positioning enhances the ability to examine capsular changes of the shoulder joint and can assist in the diagnosis of instability.Level of EvidenceIII, retrospective comparative study     

Increased plasma levels of LDL cholesterol in rabbits after adenoviral overexpression of human scavenger receptor class B type I

Scavenger receptor class B type I (SR-BI), a CD36 family member, plays a key role in high-density lipoprotein (HDL) metabolism, reverse cholesterol transport, and whole body cholesterol homeostasis, and is shown to be involved in the development of atherosclerosis in mice. In this report, we describe the effects of the adenoviral overexpression of human SR-BI (hSR-BI) in New Zealand White (NZW) rabbits, a wild-type animal model that expresses cholesteryl ester transfer protein (CETP) in plasma, displays a manlike lipoprotein profile, and is susceptible to atherosclerosis. A total of 1×10¹² adenoviral particles containing either hSR-BI or lacZ complementary deoxyribonucleic acid (control) were infused into the ear vein of NZW rabbits. Transgene expression was ascertained by TaqMan Real Time polymerase chain reaction measurements. Rabbits infected with Ad/hSR-BI (adenoviral plasmids containing hSR-BI) showed a faster clearance of administered [³H]HDL cholesterol and significantly decreased apolipoprotein (apo) A-I levels when compared to control rabbits, respectively. Interestingly, we found markedly increased levels of low-density lipoprotein (LDL) cholesterol exclusively in SR-BI-overexpressing rabbits. These changes were not accompanied by alterations in LDL receptor expression but by increased levels of CE transfer in these animals. By lowering HDL cholesterol and increasing plasma apoB-containing lipoprotein levels, the overexpression of SR-BI leads to a lipoprotein pattern, which is believed to enhance the development of atherosclerosis. The role of SR-BI in lipoprotein metabolism and atherogenesis in rabbits—a CETP-expressing animal model displaying a manlike lipoprotein profile—may therefore be different from the one found in rodents.     

The Relative Importance of Mutagens and Carcinogens in the Diet

Known mutagens and carcinogens in the diet were compiled and the risk of cancer was estimated on the basis of average exposure levels in Switzerland and carcinogenic potencies from rodent bioassays. The analysis showed that, except for alcohol, the sum of all known dietary carcinogens could only explain a few percent of the cancer deaths attributed by epidemiologists to dietary factors. The discrepancy was explained by a “carcinogenicity” of excess macronutrients. This hypothesis was based on an evaluation of dietary restriction experiments in rats and mice, where a dramatic reducing effect on spontaneous tumour formation was seen. From these experiments, a "carcinogenic potency" was deduced for food in excess (TD₅₀ approximately 16 g/kg per day). Overnutrition in Switzerland was converted into excess food intake and the cancer risk estimated on the basis of the TD₅₀ value. The resulting risk of 60,000 cases per one million lives would allow to explain by overnutrition almost all "diet-related" cancer deaths in humans.     

Poisoning in children

Drug-induced poisoning of children represents a serious medical as well as a social problem linked both to the fields of prevention and therapy. This paper analyses the occurrence and the causative agents of poisoning cases of children under the age of 15, hospitalized in a children's hospital over a two-year period (1985–1986). 33 Poisoning cases represented 1.7% of all hospitalizations, and 49% thereof were induced by drugs.     

Effects of carbonyl cyanide p-trichloromethoxyphenylhydrazone (CCCP) and of ruthenium red (RR) on capsaicin-evoked neuropeptide release from peripheral terminals of primary afferent neurones

Summary In the superfused isolated rat urinary bladder, capsaicin as well as electrical field stimulation evoked the release of calcitonin gene-related peptide-like immunoreactivity (CGRP-IR). Carbonyl cyanide p-trichloromethoxyphenylhydrazone (CCCP, threshold 2 M) reduced both, the capsaicin- and the electrical field stimulation-evoked release of CGRP-IR while a low concentration of Ruthenium Red (RR, 0.6 M and 2 M) selectively attenuated the capsaicin-evoked release of CGRP-IR but did not influence the effect of electrical field stimulation. 20 M RR nearly abolished the capsaicin-evoked release, but also attenuated the effect of electrical field stimulation.In the isolated guinea-pig bronchus, electrical field stimulation and capsaicin induced non-cholinergic contractions which are known to be caused by tachykinin release from afferent nerve terminals. CCCP (0.6 M) only reduced the response to field stimulation; a ten-fold higher concentration of CCCP attenuated field stimulation as well as capsaicin-induced contractions. This is in contrast to the reported selective inhibition of capsaic-ininduced contractions by RR.The present data demonstrate that CCCP generally inhibits evoked neuropeptide release, regardless of the kind of stimulation used while low concentrations of RR preferentially inhibit capsaicin-evoked neuropeptide release.Send offprint requests to: R. Amann at the above address     

A molecular scheme for the reaction between γ-aminobutyric acid and the most abundant chloride channel on crayfish deep extensor abdominal muscle

Single-channel measurements were performed with the aim of constructing a detailed molecular scheme for the reaction between -aminobutyric acid (GABA) and a chloride channel of crayfish deep extensor abdominal muscle (DEAM). GABA was applied in pulses to outside-out patches of muscle membrane, and, based on the dose-response of the peak currents and of their rise times, a linear model with five binding steps has been proposed. Evaluation of the single-channel kinetics indicated at least three open states. Two of them originate most probably from the fully liganded receptor state and are grouped in mixed bursts due to their different life times. The third one appears independently, outside the bursts, and originates from a lower liganded receptor state. Simulations of the dose-responses and the open time distributions with this model led to a set of rate constants which generated relatively optimal fits.     

Postocclusive cutaneous vasodilatation mediated by substance P

1. The cutaneous vasodilatation following arterial occlusion ("reactive hyperemia") was studied in the rat hind paw. A peak increase in venous outflow of 200-250% was observed within 1 min after a 3 min occlusion period. 2. Chronic denervation as well as capsaicin pretreatment reduced the postocclusive cutaneous vasodilatation by more than 60% (P less than 0.01). This demonstrates that the reactive vasodilatation is of neurogenic origin and mediated by small diameter afferent fibres. 3. Reduction of the postocclusive cutaneous vasodilatation after histamine depletion by compound 48/80 indicates the involvement of histamine. 4. Among all neuropeptides known to occur in primary sensory neurones only substance P and vasoactive intestinal polypeptide cause vasodilatation when infused i.a. into the rat paw. In contrast to antidromic sensory nerve stimulation or i.a. substance P infusion, vasoactive intestinal polypeptide does not cause plasma extravasation. The vasodilator potency of vasoactive intestinal polypeptide is about 1/500 of substance P in the rat paw. Therefore only substance P is able to mimic the reactive vasodilatation. 5. It is concluded that the postocclusive cutaneous vasodilatation is caused mainly by the release of substance P from peripheral endings of small diameter nerve fibres. The "axon reflex", also involving neurogenic vasodilatation, is assumed to be exerted by the same mechanism.     

The pathophysiology of enterocutaneous fistulas

The patient with an enterocutaneous fistula represents a high-risk situation with overall mortality rates of up to 20%, depending on the series. Treatment of these patients to a successful outcome requires attention to detail and, if necessary, meticulous operative technique. For convenience, care of these patients is divided into 5 phases:

1. Stabilization. Resuscitation with crystalloid colloid and/or blood. Drainage of only obvious abscesses. Beginning of local wound care. Initiation of nutritional support.
2. Investigation. Radiographic investigation of local fistula area, principally by sinography and, if necessary, other contrast studies. Purpose of these studies is to determine likelihood of spontaneous closure with nutritional support.
3. Decision. Is operation indicated and, if so, when? A decision must be made as to the necessity for operative closure in situations in which the fistula appears anatomically favorable but shows no signs of closure.
4. Definitive therapy—either spontaneous closure or operation. If the latter, careful preparation is required. Resection and end-to-end anastomosis gives the best results.
5. Healing phase. Nutritional support should not be discontinued too soon for fear of breakdown of newly laiddown protein.

With experience and proper management, relatively high success rates can be achieved.