The influence of passive stretch and NF-κB inhibitors on the morphology of dystrophic muscle fibers

The triangularis sterni (TS) is an expiratory muscle that is passively stretched during inspiration. The magnitude of passive stretch depends upon the location of individual fibers within the TS muscle, with fibers located more caudally being stretched ∼ 5% to 10% more than fibers in the cephalad region. In the mdx mouse model for muscular dystrophy, the TS exhibits severe pathological alterations that are ameliorated by treatment with inhibitors of the NF-κB pathway. The purpose of this study was to assess the influence of passive stretch in vivo on fiber morphology in nondystrophic and mdx TS muscles, and the morphological benefits of treating mdx mice with two distinct NF-κB inhibitors, pyrrolidine dithiocarbamate (PDTC), and ursodeoxycholic acid (UDCA). Transmission electron microscopy revealed Z-line streaming, hypercontraction, and disassociation of the plasma membrane from the basal lamina in mdx fibers. In both nondystrophic and mdx TS muscles, fiber density was larger in more caudal regions. In comparison with nondystrophic TS, fibers in the mdx TS exhibited substantial reductions in diameter throughout all regions. In vivo treatment with either PDTC or UDCA tended to increase fiber diameter in the middle and decrease fiber diameter in the caudal TS, while reducing centronucleation in the middle region. These results suggest that passive stretch induces hypercontraction and plasma membrane abnormalities in dystrophic muscle, and that differences in the magnitude of passive stretch may influence fiber morphology and the actions of NF-κB inhibitors on dystrophic morphology.

Determination of Insulin Requirements: Excessive Insulin Dosages Common in Type 1 Diabetes Mellitus

OBJECTIVE

To report our experience of determining insulin requirements for initiating continuous subcutaneous insulin infusion (CSII) pump therapy, using an algorithm for intravenous administration of insulin, in patients with poorly controlled diabetes.

METHODS

We describe assessment of insulin requirements and analyze data from 27 consecutive admissions. All patients had type 1 diabetes mellitus and were being converted to CSII pump therapy. Twenty-four-hour intravenous insulin requirements were used to initiate CSII pump therapy, and further dose adjustments were undertaken, to optimize glycemic control. Basal, bolus, and total daily insulin requirements were calculated before, during, and 3 months after conversion to CSII therapy.

RESULTS

At entry, the mean glycohemoglobin was 11.2% (normal, 5.0 to 8.0%), and the mean daily insulin dose were 45.8 U (0.59 U/kg). Calculated daily insulin requirements using an algorithm for intravenously administered insulin were 37.3 U (0.50 U/kg). At 3 months, mean daily insulin requirements had increased to 39.2 U (0.52 U/kg), and glycohemoglobin improved to 9.4%. Most patients (78%) remained on insulin doses within 10% of the calculated requirements. All patients who were receiving more than 0.6 U/kg daily before assessment required a reduction in insulin dosage to improve glycemic control.

CONCLUSION

Many patients with type 1 diabetes are receiving excessive insulin doses. An algorithm for intravenous administration of insulin may be useful for determining requirements and appropriate insulin doses for CSII pump therapy, especially in patients with poor glycemic control.

The effects of platelet-derived growth factor in cultured microvessel endothelial cells

The effects of platelet-derived growth factor (PDGF) on thymidine incorporation into DNA and glucose and neutral amino acid uptake were studied in endothelial cells cultured from macrovessels (bovine aorta and pulmonary artery) and microvessels (bovine fat and mouse brain). Similar to previous studies, PDGF did not bind to macrovessel cells, nor did it influence their metabolic function. In contrast, PDGF bound specifically to the two types of microvessel cell culture and in these cells also stimulated the uptake of glucose and neutral amino acids as well as the incorporation of thymidine into DNA. Stimulatory effects of PDGF occurred at concentrations of 2 ng/ml, with maximal stimulation up to 5-fold of the control value for amino isobutyric acid and glucose uptake and up to 8- to 10-fold for thymidine incorporation. The maximal effects of PDGF were additive to those of insulin-like growth factor, I, a known stimulator of all three metabolic processes in microvessel endothelial cells. The binding of PDGF to the endothelial cells was, in general, equivalent to PDGF binding to human foreskin fibroblasts, both in the magnitude of tracer binding and in the affinity of binding. Similar effects were found with recombinant and platelet-derived PDGF. We conclude that these two cultured microvessel endothelial cells not only produce PDGF-like material, but are capable of binding and responding to PDGF.

The Type A behaviour pattern and self-evaluation

This paper is concerned with how Type A and B subjects perceive themselves. Subjects first completed a unidimensional A type measure, then rated themselves and their ideal selves on various personality traits. As expected, Type A was associated with negative self-ratings and high actual-ideal self-discrepancy scores. However, it is argued that self-evaluation in negative terms by Type As is not necessarily synonymous with low self-esteem. Negative self-ratings may be an important factor in the aetiology and maintenance of the Type A behaviour pattern.

The attribution of cure

Subjects rated the importance of 24 different contributors towards overcoming four relatively common problems: alcoholism, depression, sexual problems and shyness. Factor analysis revealed seven almost identical clusters for each problem, which were labelled inner control, receiving help, understanding, social consequences, physical basis, avoidance and fate. Items loading on the first three factors were thought to be generally important, and those on the last three relatively unimportant. However, the degree of importance attributed to each factor varied considerably between problems.

Errors in computation of WISC and WISC-R intelligence quotients from raw scores

Twenty-four per cent of 457 sequential IQ assessments contained errors in the calculation of verbal, performance or full scale IQ's from the raw scores; in 2% the errors were large enough to cause a difference in full scale IQ of more than 5 points.

Prophylactic antiarrhythmic therapy of high-risk survivors of myocardial infarction: lower mortality at 1 month but not at 1 year

To determine whether prophylactic antiarrhythmic therapy influences mortality in high-risk patients after acute myocardial infarction, 143 such patients were randomized in a double-blind individually dose-adjusted, placebo-controlled trial an average of 14 +/- 7 days after myocardial infarction and followed for 1 year. Patients were judged to be at high risk on the basis of (1) ejection fraction less than 40% (n = 60), (2) arrhythmias of Lown class 3 or higher (n = 26), or (3) both (n = 57). Aprindine was chosen because of its long half-life, few side effects, and antiarrhythmic efficacy. Baseline characteristics in the treatment arms did not differ. Holter-detected arrhythmias were reduced in aprindine-treated patients at 3 months (p less than .001) and at 1 year (p less than .001). One patient was lost to follow-up; in the remaining patients 1 year mortality was 20% (28/142; 12 aprindine and 16 placebo). There was no significant difference between the two study arms in overall mortality and sudden death. However, among those who died, median duration of survival was longer in aprindine-treated patients (86 vs 21.5 days) (p = .04). Although antiarrhythmic treatment with aprindine of high-risk patients after myocardial infarction does not affect 1 year survival, mortality appears to be delayed; thus there may be a role for short-term treatment before more definitive therapy such as surgery.

Type A behaviour pattern, the recall of positive personality information and self-evaluations

This paper reports on two studies of how Type A and B subjects perceive themselves. Both studies investigated differences in self-ratings of personality by Type As and Bs, and differences in the recall of positive and negative personality information. As predicted, a modest significant positive correlation was found in both studies between Type A scores and number of positive traits remembered, suggesting that Type A behaviours are associated with a tendency to process information about the self in such a way as to bolster self-esteem. Self-ratings of positive and negative personality traits showed that Type As tended to rate themselves much more negatively than Type Bs. This provides support for a self-evaluative model of Type A behaviour. The results are discussed in terms of the paradoxical nature of the Type A behaviour pattern.

A new projective test: the Caine-Marteau-Dympna Test (CMD)

The Caine-Marteau-Dympna (CMD) Test, a new thematic apperception projective test, has acceptable inter-rater reliability. Validity was demonstrated by its ability to differentiate psychiatric in-patients from out-patients and non-patients, and by the relationships found between ratings derived from the test protocols and various questionnaires. These latter provide measures associated with either an inner or outer orientation towards the world. This has implications for many different areas of life, including occupational preference and adjustment, psychiatric symptom formation, psychological treatment expectancies and therapeutic outcome. Thus, the inner oriented individual, who is likely to be responsive to interpretative psychotherapy, tends to produce CMD responses displaying individualistic, abstract themes; a concern with intrapsychic conflict, deficiencies in social interaction and lack of structure; and internal control.

Who goes home? Predictive factors in stroke recovery

One hundred and seventy two stroke patients were assessed two weeks post-stroke by a multi-disciplinary team. The predictive ability of a number of variables, including social, psychological and physical factors, was estimated for four outcome groups. Highly significant factors for good and bad outcome for one year were identified.