Broadband TDMA over the indoor radio channel

Prior work has focused on the negative aspects of time-dispersive channels and associated intersymbol interference. The authors show that the inherent diversity introduced by such dispersion is advantageous in reducing the performance-limiting effects of flat fading. This is demonstrated for an indoor QPSK radio link employing a decision-feedback equaliser     

Psychopharmacotherapy for addictive and comorbid disorders: current studies

Proper diagnosis of comorbid disorders is crucial in treatment planning for the dually diagnosed. Since psychoactive substance use can obfuscate the diagnosis, special care must be taken to exclude organically based syndromes. Adequate periods of abstinence should first be achieved and subsequently the patient re-examined for residual symptoms compatible with a nonaddictive, nonsubstance-induced psychiatric disorder. The integration of concurrent treatment of both the mental and the addictive disorders appears to be the best approach for treatment of comorbid psychiatric and addictive disorders. An abstinence-based model that typically utilizes a 12-step group therapy is often employed for the addictive illnesses. Other forms of psychosocial therapies such as case managers are being used as well. Presently, physicians' prescribing practices for comorbid addicted patients are based on traditional approaches to use of medications in psychiatric patients, and their attitudes towards addictive disorders may play a significant role in determining the overall success of treatment.     

The amylose and lipid contents,dimensions, and gelatinisation characteristics of some wheat starches and their A- and B-granule fractions

Starches isolated from 23 bread wheats (Triticum aestivum) and 26 durum wheats (T. durum) contained 26.3-30.6% (mean 29.1%) total amylose, 19.3–25.1% (mean 22.9%) apparent amylose and 783–1144mg 100g^?1 (mean 977 mg 100g^?1) lysophos-pholipids. Gelatinisation temperatures were 57.3–64.9°C (mean 61.8°C) and enthalpies 6.4–11.8 Jg^?1 (mean 9.7Jg^?1) in excess water, measured by differential scanning calorimetry. There were no correlations between any of these parameters. Starch granule size distributions were determined with a Coulter Counter and 100–channel analyser. A-granule mean volumes were 1235–2585μm³ (av. 1778), modal volumes 863–1804μm³ (av. 1264), mean diameters 13.9–16.0μm (av. 13.99), and specific surface areas 0.236–0.302m²g^?1. B-granule mean volumes were 35.4–100.4μm³ (av. 55.9), modal volumes 16.5–54.5μm³ (av. 27.7), mean diameters 3.66–5.07μm (av. 4.09), and specific surface areas 0.684–0.920m²g^?1. The B-granule contents of the starches were 12.8–34.6% (av. 27.3) by weight (sedimentation method) and 13.0–37.3% (av. 24.0) by volume (Coulter method), the latter being the more accurate method.     

Pharmacokinetic and pharmacodynamic effects of vaginal rings releasing levonorgestrel at a rate of 27 micrograms/24 hours: a pilot study

The pharmacokinetic and pharmacodynamic effects of vaginal rings releasing levonorgestrel (L-NOG) at an initial rate of 27 micrograms/24 h were studied in a group of 12 normally menstruating women during 90 days of continuous use (i.e., during three 30-day treatment segments). Blood samples were drawn immediately before insertion, 15 and 30 min, as well as 1, 2, 4, 8, 12 and 24 h after insertion of the rings, and thereafter three times weekly throughout the study for the analysis of L-NOG, estradiol, progesterone and sex hormone-binding globulin (SHBG). Endometrial biopsies were obtained for a morphometric analysis in a pre-treatment (control) cycle and in the 6th and 10th weeks of treatment. The peak of average L-NOG levels was reached within two hours after the insertion of rings. Until 24 h after insertion, the levels did not change significantly. Thereafter, a decrease at a rate of 0.2% per day was initiated. The L-NOG and SHBG levels were highly correlated. This was seen for both the pre-treatment SHBG vs L-NOG (r = 0.96) and the treatment SHBG vs L-NOG levels (r = 0.92). There was a significant (p < 0.001) decrease of SHBG levels due to treatment. During the total of 36 treatment segments, a normal ovarian function was seen in 47% of the segments. The women were anovulatory and had an inadequate lutal function in 28% and 25% of segments, respectively. No correlation between the L-NOG levels and ovarian reaction to treatment was found. The use of L-NOG induced significant changes in the endometrium; the number of glands/mm2 decreased after 6 (p < 0.02) and 10 weeks of use (p < 0.01). Also, the diameter of glands and the occurrence of vacuolated cells decreased significantly (p < 0.02 and p < 0.005, respectively). None of the endometrial parameters or dating was correlated with the ovarian reaction to treatment, indicating independent endometrial effects of L-NOG.     

Insulin-like growth factor I activates the invasion suppressor function of E-cadherin in MCF-7 human mammary carcinoma cells in vitro

The calcium-dependent cell-cell adhesion molecule E-cadherin has been shown to counteract invasion of epithelial neoplastic cells. Using three monoclonal antibodies, we have demonstrated the presence of E-cadherin at the surface of human MCF-7/6 mammary carcinoma cells by indirect immunofluorescence coupled to flow cytometry and by immunocytochemistry. Nevertheless, MCF-7/6 cells failed to aggregate in a medium containing 1.25 mM CaCl2, and they were invasive after confrontation with embryonic chick heart fragments in organ culture. Treatment of MCF-7/6 cells with 0.5 microgram ml-1 insulin-like growth factor I (IGF-I) led to homotypic aggregation within 5 to 10 min and inhibited invasion in vitro during at least 8 days. The effect of IGF-I on cellular aggregation was insensitive to cycloheximide. However, monoclonal antibodies that interfered with the function of either the IGF-I receptor (alpha IR3) or E-cadherin (HECD-1, MB2) blocked the effect of IGF-I on aggregation. The effects of IGF-I on aggregation and on invasion could be mimicked by 1 microgram ml-1 insulin, but not by 0.5 microgram ml-1 IGF-II. The insulin effects were presumably not mediated by the IGF-I receptor, since they could not be blocked by an antibody against this receptor (alpha IR3). Our results indicate that IGF-I activates the invasion suppressor role of E-cadherin in MCF-7/6 cells.     

Hindshaker, a novel myelin mutant showing hypomyelination preferentially affecting the spinal cord

Animals with spontaneous mutations affecting myelin formation have provided useful information about the genetic and cellular mechanisms regulating normal and abnormal myelination. In this paper we describe a novel murine mutation termed hindshaker (hsh), which is inherited in an autosomal recessive manner. Affected mice are characterised by a variable tremor of the hind end which commences at about 2 weeks of age and largely disappears in animals older than 6 weeks. There is hypomyelination affecting predominantly the spinal cord, although the optic nerves and brain are involved to a much lesser degree. The defect of thinly myelinated and naked axons is maximal at 20 days of age and largely resolves with time so that in the adult most axons are myelinated. The myelin structure appears normal and immunostains for the major proteins. Although the distribution of oligodendrocytes in the spinal cord is similar to normal during the period of hypomyelination, there are fewer mature cells. The hsh mutation appears to delay the maturation of oligodendrocytes, particularly in the spinal cord. Additionally, there is a considerable variation in phenotypic expression and in penetrance when the mutation is expressed on different genetic backgrounds, suggesting the hsh locus is subject to the influence of modifying gene(s). Identification of the hsh gene should identify a factor important in the development of oligodendrocytes, particularly those in the spinal cord.     

Electronic thermography for the assessment of acute temporomandibular joint pain

Electronic thermography (ET) has the potential to be a nonionizing, noninvasive, low-cost diagnostic alternative for evaluating temporomandibular joint (TMJ) disorders. This study was designed to evaluate the use of ET as a diagnostic aid in the assessment of patients with acute TMJ pain. Computer measurements made using facial thermography were able to distinguish normal patient populations from symptomatic patients with acute TMJ pain. Additional studies are needed before thermographic diagnosis of TMJ disorders will be clinically accepted.     

Keratin 17 gene expression during the murine hair cycle

Treatment of rats with phenytoin (DPH), an anti-epileptic drug, results in lower tissue thyroid hormone (TH) levels and interferes with the metabolic pathway of TH. To test the hypothesis that DPH affects the enterohepatic cycle of TH and, thus, the kinetics of TH turnover, we performed a kinetic experiment (three-compartment analysis) and a steady-state, double-isotope equilibrium experiment in rats treated for 3 weeks with DPH (50 mg/kg body weight per day) and in untreated controls. This included measurements of TH and TH metabolite levels, as well as the activities of enzymes involved in the TH metabolic pathway. DPH treatment resulted in a decrease in the production of thyroxine (T4) (by 25%) and tri-iodothyronine (T3) (by 37%), a decrease in the T3 concentration in all three pools, and a redistribution of T4 from the fast to the slow pool. The amount of T4 increased in intestinal contents and feces by 66% and 71% respectively. Expressed as a fraction of daily TH disposal, fecal loss of T4 was enhanced from 10 to 23% and that of T3 from 16 to 21%. An increase in T4 and T3 UDP-glucuronyltransferase activities was observed, suggesting that the increased fecal loss of T4 and T3 is secondary to an increased biliary output of their glucuronides. The reduced secretion of TH and increased fecal clearance during DPH treatment can lead in the long run to depletion of TH stores.     

Effect of ETA receptor antagonists on cardiovascular responses induced by centrally administered sarafotoxin 6b: role of sympathetic nervous system

The present study was carried out to investigate the cardiovascular effects of centrally administered SRT6b in saline, BQ123 and BMS182874 pretreated male Sprague-Dawley rats, using a radioactive microsphere technique. SRT6b (100 ng, ICV) produced a transient increase (40%) in blood pressure at 5 min followed by a sustained decrease (-42%) at 30 and 60 min in control rats. Total peripheral resistance and heart rate were not significantly altered. Cardiac output increased (16%) at 5 min and decreased 30 and 60 min following SRT6b administration. Central venous pressure was not affected by SRT6b. Regional blood flow and vascular resistance did not change at 5 min following administration of SRT6b. However, a significant decrease in blood flow to the brain, heart, kidneys, liver, spleen, gastrointestinal tract and mesentery and pancreas was observed 30 and 60 min following administration of SRT6b in control (saline treated) rats. Pretreatment with ETA selective receptor antagonists, BQ123 (10 micrograms, ICV) or BMS182874 (50 micrograms, ICV) significantly attenuated the pressor and depressor effects of centrally administered SRT6b. SRT6b induced decrease in blood flow was completely blocked by pretreatment with BQ123 or BMS182874. ET-1 (100 ng, ICV) produced an increase followed by a decrease similar to SRT6b. Reserpine (5 mg/kg, IP) pretreatment attenuated the cardiovascular effects of ET-1. Role of sympathetic nervous system was determined by measuring splanchnic nerve activity. SRT6b when administered in the lateral cerebral ventricle did not produce any significant effect at 5 min, however, a significant decrease in sympathetic nerve activity was observed 30 min after its administration. It is concluded that centrally administered SRT6b produces significant changes in systematic and regional blood circulation which can be completely blocked by ETA receptor antagonist. The cardiovascular effects of centrally administered SRT6b appear to be mediated through the sympathetic nervous system.