Postoperative radial nerve paralysis caused by fracture callus.

This is a case of late-onset (6 weeks) radial nerve paralysis following open reduction and internal fixation of a comminuted distal humerus fracture. A transected radial nerve within the callus was found at reoperation. The mechanism of transection was thought to be repetitive motion of the nerve across an edge of new bone. The nerve was repaired and tendon transfers done subsequently with less than full functional recovery at 16 months. No such case has been previously reported.     

CLINICAL ASSESSMENT OF AN ENZYME IMMUNOASSAY (EMIT) FOR MEASUREMENT OF SERUM SALICYLATE

Salicylic acid concentrations in serum were compared using a homogenous enzyme immunoassay (EMIT) and an automated colorimetric analysis (ACA) technique. Analysis of samples showed similar within-day and day-to-day coefficients of variation (CV): 1.3% and 4.6% by EMIT and 1.0% and 2.6% by ACA, respectively. Quantification of serum containing added salicylate and serum from patients receiving salicylate therapy showed a slight positive bias towards the ACA method over the range of 0-600 mg/l. No significant difference in reliability was found between the two methods. The EMIT assay showed no interference from other antiflammatory drugs being taken by patients who were not taking salicylates. If decisions to alter salicylate dosage are made with due regard to the drug's saturation kinetics, measurements using either EMIT or ACA should allow the clinician to titrate patients' serum concentrations accurately within the narrow therapeutic range.     

Sinusoidal lining cell damage: the critical injury in cold preservation of liver allografts in the rat

We have previously defined viability limits in a rat transplantation model. All liver allografts stored in a simple preservation solution (NaCl 0.9%, CaCl2 2 mM) at 4 degrees C for 4 hr or at 37 degrees C for 1 hr were viable upon transplantation, but all those stored at 4 degrees C for 8 hr or at 37 degrees C for 2 hr were nonviable. Only cold-preserved, nonviable livers showed increased vascular resistance, platelet trapping and an initially low, but then high, rise in aspartate transaminase (AST) upon reperfusion, all suggesting injury to the microcirculation, with secondary injury to the hepatocyte. In the present study, we investigated the morphological changes that occur in livers stored for the defined critical times, using light and electron microscopy after perfusion-fixation. Accurate and reproducible identification of specimens as belonging to viable or nonviable and warm- or cold-preserved could be made in this way. Preservation in the cold first resulted in reversible changes consisting of cellular swelling, alterations of intracellular organelles, and partial denudation of the sinusoidal lining (cold-preserved viable group). Later, under conditions of nonviable cold preservation, detachment of cell bodies of sinusoidal lining cells with nuclear changes and almost complete denudation of the sinusoidal lining was observed. Endothelial cells of larger vessels were only injured mildly. In contrast, under conditions of warm preservation, changes involving mitochondria and later nuclei were found in hepatocytes, and blebbing was more extensive. Endothelial cells were spared relatively. We also examined livers stored in isotonic citrate solution at 4 degrees C for 8 hr and 16 hr, the critical times determined for this solution in another model of rat liver transplantation. The findings were very similar to storage in saline with respect to the changes in the sinusoidal lining cells after cold preservation for the two critical times. The results provide convincing evidence of a qualitative difference between warm and cold preservation injury, with relatively selective damage to hepatocytes or sinusoidal lining cells, respectively. Endothelial damage represents the primary event, resulting in the loss of organ viability following hypothermic storage. Thus morphology may serve as a useful viability marker after preservation.     

Presynaptic serotonin mechanisms in rats subjected to inescapable shock.

After exposure to uncontrollable shock training, two distinct groups of rats can be defined in terms of their performance in learning to escape from a controllable stress. Learned helpless rats do not learn to terminate the controllable stress, whereas non-learned helpless rats learn this response as readily as naive control rats do. The present studies were designed to examine the correlations between the behavioral differences and the changes of presynaptic serotonergic activity, seen in these groups of rats. The major findings concerned presynaptic serotonergic effects in the hippocampus and hypothalamus of learned helpless rats. In the hippocampus, these included a statistically significant increase in three presynaptic 5-hydroxytryptamine (5-HT) mechanisms: K(+)-induced release of [3H]serotonin, high affinity uptake of [3H]serotonin and maximum density of binding sites for uptake of 5-HT, measured with [3H]paroxetine. In the hypothalamus, there was a differential modulation of all three presynaptic 5-HT mechanisms. A significant decrease in: K(+)-induced release of [3H]serotonin, in high affinity uptake of [3H]serotonin and the maximum binding site density of [3H]paroxetine binding was observed. No changes in uptake site binding was seen in other regions of the brain examined. These results implicate presynaptic serotonin mechanisms in the behavioral deficit caused by uncontrollable shock. In addition, a limbic-hypothalamic pathway may serve as a control center for the behavioral response to stress.     

Prognostic implications of the proliferative potential of low-grade astrocytomas

The proliferative potential of low-grade astrocytomas was estimated in 47 patients. Each patient received an intravenous infusion of bromodeoxyuridine (BUdR), 150 to 200 mg/sq m, at the time of craniotomy to label cells in deoxyribonucleic acid (DNA) synthesis; the percentage of S-phase cells, or BUdR labeling index (LI), of each tumor was determined immunohistochemically. In 29 patients (60%), the tumors had BUdR LI's of less than 1%, indicating a slow growth rate; only three (10%) of these patients died of recurrent tumor during a follow-up period of up to 3 1/2 years. In contrast, of the 18 patients (40%) whose tumors had BUdR LI's of 1% or more, 12 (67%) had a recurrence and nine died during the same follow-up period. These results show that the proliferative potential, as reflected by the BUdR LI, is an important prognostic factor that separates low-grade astrocytomas into two groups and provides a more scientific rationale for selecting treatment for individual patients.     

Antigenic structure of bovine growth hormone: location of a growth enhancing region.

Site-directed antisera generated by peptide immunization have been used to study the antigenicity of bovine growth hormone (bGH). Prediction of sequential antigenic sites has been performed using secondary structure information derived from the 'Protean' prediction routine. The structures predicted by this programme agree closely with the corresponding structure of GH recently derived from crystallographic studies. We have previously shown that the binding of monoclonal antibodies of particular epitope specificity to human or bovine GH results in significant enhancement of hormonal activity in vivo; however, the sites recognized by these antibodies were not known. Here we identify a sequence region, corresponding to a loop structure joining helices 3 and 4, which, is associated with the growth enhancement phenomenon. Antisera raised to either of two overlapping peptides (residues 120-140 and 134-154) significantly increase the biological activity of GH in vivo. Antisera directed to other regions on the GH molecule failed to demonstrate this property. Coincidentally, the sites recognized by the growth-enhancing anti-peptide antisera overlap with the site on GH which is highly susceptible to proteolytic cleavage; such cleavage has been shown in some cases to result in hormone enhancement.     

Expression profiling of metalloproteinases and inhibitors in cartilage

Objective   To profile the expression of all known members of the matrix metalloproteinase ( MMP ), a disintegrin and metalloproteinase with thrombospondin motifs ( ADAMTS ), and tissue inhibitor of metalloproteinases ( TIMP s) gene families in normal cartilage and that from patients with osteoarthritis (OA).
Methods   Human cartilage was obtained from femoral heads at joint replacement for either osteoarthritis or following fracture to the neck of femur. Total RNA was purified and expression of genes assayed using quantitative real-time PCR.
Results   Several members of the above gene families were regulated in OA. Genes increasing in expression in OA were: at P  < 0.001, MMP-13 , MMP-28 , ADAMTS-16 ; at P  < 0.01, MMP-9 , MMP-16 , ADAMTS-2 , ADAMTS-14 and at P  < 0.05, MMP-2 , TIMP-3 , ADAMTS-12 . Genes decreasing in expression in OA were: at P  < 0.001, MMP-1 , MMP-3 , ADAMTS-1 ; at P  < 0.01, MMP-10 , TIMP-1 , ADAMTS-9 and at P  < 0.05, TIMP-4 , ADAMTS-5 , ADAMTS-15 . Correlation analysis revealed that groups of genes across the gene families are co-expressed in cartilage.
Conclusion   This is the first comprehensive expression profile of all known MMP , ADAMTS and TIMP genes in cartilage. Patterns of expression provide a foundation on which to understand mechanisms of gene regulation in OA and potentially for refining the specificity of anti-proteolytic therapies.     

High-risk endometrial cancer in young indigent women

OBJECTIVE: The aim of this study was to evaluate a different prevalence and clinical pattern of high-risk endometrial cancer in an indigent population of young women. METHODS: Charts of 71 consecutive patients, treated for endometrial adenocarcinoma during a 6-year period, were reviewed. The patients were divided into two groups contingent upon age--(i) those who were below 40 years and (ii) those who were over 40. Based on histological type, grade, and stage, both groups were subdivided into a low, intermediate, or high-risk cancer category. RESULTS: Of the 13 (18.3%) patients in the younger age group, five patients (38.4%) had high-risk endometrial cancer, compared to only eight patients (13.8%) in the older age group. CONCLUSION: In contradiction to previous reports, our results show that a higher proportion of young indigent women diagnosed with endometrial cancer have a high-risk cancer. Delay in diagnosis can explain only some of the discrepancies in the special clinical pattern of endometrial cancer among this population. Other possible explanations include nutritional differences, genetic susceptibility, immunological status, and high-risk behavior. More epidemiological studies are needed for complete understanding of the unfavorable outcome of endometrial cancer in these young women.