Expression analysis of the mixed function oxidase system in rat brain by the polymerase chain reaction

Metabolism of therapeutic drugs in the body by the mixed function oxidase system is an important consideration in the analysis of a drug's effectiveness. P450-dependent metabolism within the brain of a neuro-specific drug may affect the drug's course of action. To determine whether cytochrome P450 was expressed in brain, RNA was isolated from the whole brains of rats treated with a variety of known hepatic P450 inducers, including amitriptyline, imipramine, isosafrole, phenobarbital, and -naphthoflavone. The RNA was analyzed for the presence of P450 isozymes by the PCR technique. Differential expression of P450IA1, P450IIB1, P450IIB2, P450IID, and P450IIE1 was detected in the brain samples, depending on the treatment. Cytochrome P450 reductase expression was also detected in the brain samples, giving strong evidence that the brain contains a competent mixed function oxidase system under all conditions studied. (Mol Cell Biochem120: 171–179, 1993)Thesis student of the Graduate School of Biomedical Sciences, the University of Texas Health Science Center at Houston     

The mATPase histochemical profile of rat type IIX fibres: correlation with myosin heavy chain immunolabelling

Summary In the present study we report a novel histochemical method which, by sequential pre-incubations in alkaline and acidic media, selectively differentiates muscle fibres expressing myosin heavy chain IIX, on the basis of a specific profile for myofibrillar actomyosin ATPase (mATPase) activity. The enzyme reactions were tested for specificity by means of anti-myosin heavy chain monoclonal antibodies, which were characterized on Western blots of muscle homogenates. Enzyme histochemical reactions with the traditional pH buffers were compared to those of the new method and, in conjunction with the immunoreactions, used to confirm the relationship between MyHC expression and the distinct profiles for mATPase. Imrnunohistochemical reactions demonstrated that the new method only differentiates those fibres expressing myosin heavy chain IIX. The method revealed a continuum in which the intermediate staining intensities corresponded to hybrid fibres expressing myosin heavy chain IIX in combination with either the IIA or IIB forms. Quantitative histochemistry and immunohistochemistry (by image analysis), used to examine the relationship between staining intensities for mATPase and amounts of myosin heavy chain IIX expression, revealed that the new method discriminates well between hybrid fibres expressing variable amounts of the IIX isoform (r² = 0.93).     

Randomised controlled trial of graded exercise in patients with the chronic fatigue syndrome.

OBJECTIVE: To test the efficacy of a graded aerobic exercise programme in the chronic fatigue syndrome. DESIGN: Randomised controlled trial with control treatment crossover after the first follow up examination. SETTING: Chronic fatigue clinic in a general hospital department of psychiatry. SUBJECTS: 66 patients with the chronic fatigue syndrome who had neither a psychiatric disorder nor appreciable sleep disturbance. INTERVENTIONS: Random allocation to 12 weeks of either graded aerobic exercise or flexibility exercises and relaxation therapy. Patients who completed the flexibility programme were invited to cross over to the exercise programme afterwards. MAIN OUTCOME MEASURE: The self rated clinical global impression change score, "very much better" or "much better" being considered as clinically important. RESULTS: Four patients receiving exercise and three receiving flexibility treatment dropped out before completion. 15 of 29 patients rated themselves as better after completing exercise treatment compared with eight of 30 patients who completed flexibility treatment. Analysis by intention to treat gave similar results (17/33 v 9/33 patients better). Fatigue, functional capacity, and fitness were significantly better after exercise than after flexibility treatment. 12 of 22 patients who crossed over to exercise after flexibility treatment rated themselves as better after completing exercise treatment 32 of 47 patients rated themselves as better three months after completing supervised exercise treatment 35 of 47 patients rated themselves as better one year after completing supervised exercise treatment. CONCLUSION: These findings support the use of appropriately prescribed graded aerobic exercise in the management of patients with the chronic fatigue syndrome.     

Post-thawing survival of motile ram sperm after isolation by layering on protein columns

Post-thawing survival of ram sperm was examined after semen which had been layered on top of isolation columns containing solutions of bovine serum albumin (BSA) in Tris diluent was processed for freezing by the pellet method. Sperm isolated from the bottom of the BSA column had better post-thawing survival than sperm from the top of the column. The efficiency of sperm isolation was affected by the concentration of BSA in the column, the holding time of semen on the column and the concentration of sperm in the layered semen. The best post-thawing survival of sperm occurred when semen diluted to a concentration of 200 x 10(6) sperm/ml was layered on a column of 6% BSA in Tris diluent and the bottom layer of the column was isolated for freezing after two hours' holding time.     

The effect of alpha, alpha'-bis[3-(N,N-diethylcarbamoyl)piperidino]-p-xylene on human blood platelet structural physiology

alpha, alpha'-Bis[3-(N,N-diethylcarbamoyl)piperidino]-p-xylene enhances human blood platelet membrane integrity by exerting a stabilizing action at the level of the dense tubular system in surface membrane complexes known to sequester platelet calcium.     

Production of an insulin-like growth factor by osteosarcoma

To test the possibility that osteosarcoma cells produce their own growth factors, we measured levels of insulin and somatomedin C (SMC), an insulin-like growth factor, in culture media of two cell lines derived from patients with that disease. SMC but not insulin levels increased three- to ten-fold over a period of 7 days paralleling the increases in cell number. Production of SMC was inhibited by cycloheximide.     

An analysis of repeated sequence heterogeneity

High-resolution thermal denaturation was used to measure the heterogeneity within repeated DNA sequences. An analysis of combined denaturation/redenaturation experiments on mouse satellite DNA suggests the existence of two minor components, one of which does not appear in the prepared EcoRII monomer. The resolving power of the denaturation/redenaturation experiment is estimated and contrasted with that of the reassociation experiment, often used to estimate repeated sequence heterogeneity. A mathematical model of the redenaturation experiment was developed and applied to mouse satellite data; the results suggest that only one-fourth of the mismatched base pairs are energetically significant in the reduction of heteroduplex stability.