Cochlear ablation alters acoustically induced c-fos mRNA expression in the adult rat auditory brainstem

Expression of c-fos mRNA was studied in the adult rat brain following cochlear ablations by using in situ hybridization. In normal animals, expression was produced by acoustic stimulation and was found to be tonotopically distributed in many auditory nuclei. Following unilateral cochlear ablation, acoustically driven expression was eliminated or decreased in areas normally activated by the ablated ear, e.g., the ipsilateral dorsal and ventral cochlear nuclei, dorsal periolivary nuclei, and lateral nucleus of the trapezoid body and the contralateral medial and ventral nuclei of the trapezoid body, lateral lemniscal nuclei, and inferior colliculus. These deficits did not recover, even after long survivals up to 6 months. Results also indicated that neurons in the dorsal cochlear nucleus could be activated by contralateral stimulation in the absence of ipsilateral cochlear input and that the influence of the contralateral ear was tonotopically organized. Results also indicated that c-fos expression rose rapidly and persisted for up to 6 months in neurons in the rostral part of the contralateral medial nucleus of the trapezoid body following a cochlear ablation, even in the absence of acoustic stimulation. This response may reflect a release of constitutive excitatory inputs normally suppressed by missing afferent input or changes in homeostatic gene expression related to sensory deprivation. Instances of transient, surgery-dependent increases in c-fos mRNA expression in the absence of acoustic stimulation were observed in the superficial dorsal cochlear nucleus and the cochlear nerve root on the ablated side.     

The CD4+ T lymphocyte is a site of steroid resistance in asthma

Phytohaemagglutinin (PHA)-induced T-cell proliferation is suppressed completely in steroid-sensitive asthma (SSA) by fluticasone propionate (FP). By contrast, in patients with steroid-resistant asthma (SRA), this proliferative response is only partially attenuated by steroids, which suggests that the T lymphocyte may harbour a key molecular defect in these patients. Both CD4+ and CD8+ T cells may be involved in orchestrating the inflammation underlying asthma. We examined whether CD4+ or CD8+ T cells isolated from SRA and SSA patients are equally susceptible to steroid suppression of PHA-induced proliferation. Complete suppression of CD4+ T-lymphocyte proliferation was seen in both SSA and control subjects at concentrations of 10(-9) M FP. In contrast, proliferation of CD4+ T cells from SRA patients was only partially inhibited, even at 10(-6) M FP. CD8+ responses from SRA, SSA and controls were all similar, with only a partial suppression of proliferation at 10(-6) M FP. Differential suppression by FP of CD4+ T cells has thus been demonstrated between SRA and SSA patients.     

User capacity for synchronous multirate CDMA systems with linear MMSE receivers

The performance of linear minimum mean-square error (MMSE) multiuser receivers in a dual-rate synchronous direct-sequence code-division multiple-access (DS-CDMA) system is investigated using the random spreading sequence analysis. Multicode (MC) systems and different variants of variable spreading length (VSL) systems are studied. User capacity regions are obtained for these systems.     

Tailed. New options in therapy of bronchial asthma

A correct access opening is the key to endodontics. An adequate anatomical access preparation maximizes cleaning, shaping, and obturation. The major objectives of access preparation are straight line access to the apical area, conservation of tooth structure, and unroofing of the pulp chamber. The safe-ended diamond bur technique provides an efficient and rapid means to obtain the objective of access preparation in posterior teeth.     

The effects of perindopril on vascular smooth muscle polyploidy in stroke-prone spontaneously hypertensive rats

OBJECTIVE: To quantify vascular smooth muscle polyploidy and growth kinetics in aortic cells from stroke-prone spontaneously hypertensive rats (SHRSP) and from normotensive Wistar-Kyoto (WKY) rats, and to examine the effects of treatment with the angiotensin converting enzyme (ACE) inhibitor perindopril on these parameters. DESIGN: The following experimental groups were used: young (age < 20 weeks) and old (age > 20 weeks) untreated WKY rats and untreated SHRSP; SHRSP treated with perindopril, and age- and sex-matched control SHRSP; and SHRSP treated with hydralazine and hydrochlorothiazide and age- and sex-matched control SHRSP. The effects of treatment of the SHRSP with perindopril for 30 days on vascular smooth muscle polyploidy and growth kinetics were measured and compared with the effects of equivalent antihypertensive doses of hydralazine and hydrochlorothiazide. METHODS: Vascular smooth muscle polyploidy was measured using flow-cytometry DNA analysis of freshly harvested cells. Growth curves were performed on cultured aortic cells. Plasma renin activity was measured by an antibody-trapping method, plasma angiotensin II (Ang II) by radioimmunoassay and plasma ACE activity by a colorimetric method. Cardiac hypertrophy was evaluated by measuring the heart weight:body weight and left ventricle + septum weight:body weight ratios. RESULTS: The SHRSP had markedly and significantly elevated G2 + M phase of the cell cycle. Treatment with perindopril resulted in a significant reduction in polyploidy in the SHRSP, whereas treatment with hydralazine and hydrochlorothiazide had no effect on the percentage of cells in the G2 + M phase of the cell cycle. The regression of polyploidy after treatment with perindopril was associated with a significant reduction in the concentration of Ang II and ACE activity, and with a significant regression of cardiac hypertrophy. Increased mitogenesis of cultured vascular smooth muscle cells from the SHRSP was not altered by treatment with perindopril. CONCLUSIONS: ACE inhibition reduces vascular smooth muscle polyploidy in large conduit arteries. This type of vascular protection is mediated by the reduced Ang II and possibly by increased kinins level, rather than by the hypotensive effect alone.     

Relationships between gastric emptying, intragastric meal distribution and blood glucose concentrations in diabetes mellitus

The aim of this study was to evaluate the prevalence of disordered intragastric meal distribution and the relationships between gastric emptying, intragastric distribution, glycemic control and gastrointestinal symptoms in diabetes mellitus. METHODS: Eighty-six patients with diabetes mellitus had measurements of gastric emptying and intragastric distribution of a radioisotopically labeled solid/liquid meal (100 g beef and 150 ml 10% dextrose), glycemic control (plasma glucose concentrations), upper gastrointestinal symptoms (questionnaire) and autonomic nerve function (cardiovascular reflexes). Results were compared to those obtained in 20 normal volunteers. RESULTS: Solid and liquid gastric emptying were delayed in the diabetic patients and correlated weakly. Intragastric meal distribution was also often abnormal, with increased retention of both solid and liquid in the proximal stomach and increased retention of solid but not liquid in the distal stomach. In all patients with increased retention of solid in the proximal stomach, emptying from the total stomach was delayed. Gastric emptying of liquid was slower in those subjects who had a mean plasma glucose > 15 mmol/liter during the gastric emptying measurement, when compared to the remainder of the group. CONCLUSION: In patients with diabetes mellitus, there is poor relationship between solid and liquid gastric emptying and intragastric meal distribution is frequently abnormal. Interpretation of the results of gastric emptying measurements should consider meal composition and plasma glucose concentrations.     

ACTH-producing carcinoma of the pituitary with haematogenic metastases

Two laboratories equipped with CAS 200 (Becton Dickinson Image Cytometry Systems, San Jose, CA) instruments participated in this study of variability of DNA analysis of bladder tumor specimens. Formalin fixed paraffin embedded specimens were disaggregated and centrifuged onto microscope slides from ten bladder tumor specimens and two specimens of normal urothelium. Sources of variability considered were Specimen, Slide, Run, Laboratory, and Error. Slides were systematically scanned and 200 cells measured followed by the operator selecting 100 nuclei with abnormal morphology. DNA index (DI) and hyperdiploid fraction (HDF) were calculated from the DNA frequency distributions. For systematic sampling, 92% of the variability was due to Specimen indicating that differences in HDF values between specimens reflect biological differences. With selective sampling, only 67% of the variability in HDF is due to Specimen differences. Other factors, Laboratory, Error, and Laboratory x Specimen interaction each accounted for approximately 10% of the variability. Similarly variability of DI with selective sampling was also higher, and less specimen dependent than systematic sampling. It is important that sampling schemes and selection criteria be carefully documented in order to control variability. Enriched (or selective) sampling for abnormal cells has the potential to increase sensitivity but specimen classification based on these measurements must depend on determination of the frequency of such cells in the total population.     

Value of determining serum cholesterol levels in patients with coronary heart disease]

Cholesterol synthesis (HMG-CoA reductase) inhibitors have proven their value in preventing cardiovascular events, especially in patients with manifest coronary heart disease. Besides cholesterol lowering a number of effects have been described which may contribute to the beneficial influence of these agents on the process of atherosclerosis. Measurement of serum lipids is still necessary for various reasons, namely, to know the degree of elevation in serum cholesterol and specific disturbances in lipid metabolism, the extent to which serum lipids must be lowered and the compliance with cholesterol lowering therapy.