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Biomedical subjects

P Morris

Publications and source records attributed to P Morris.

At least 217 records · Page 12Linked to original sources
PubMed1971

Molecular-sieve chromatography and electrophoresis in polyacrylamide gels.

1. The absolute electrophoretic mobilities of eight proteins have been measured at pH8.76, I 0.05, in polyacrylamide gels of 20 different compositions at 10 degrees C. 2. The partition coefficients of these proteins have been determined chromatographically under the same conditions by using columns of granulated polyacrylamide gel prepared simultaneously. 3. The electrophoretic mobilities are an exponential function of the gel concentrations when the latter are corrected for water uptake. The constants of this function have been determined by curvefitting methods. They have been shown to be related to the free solution mobility and to the mean molecular radius respectively. 4. The reduced mobilities have been shown to be a linear function of the partition coefficients by statistical analyses. 5. The physical significance of the relation between electrophoretic mobility and chromatographic phase distribution in gel media is discussed in the context of these results.

Acrylamides↗
PubMedDate not supplied

Accidents among schizophrenic outpatients.

A preliminary comparison of traffic, home, and work accident incidence was performed among 103 outpatient schizophrenic patients and an age matched sample of 123 controls. The number of motor vehicle drivers among schizophrenic outpatients was far less than among controls (70 of 103 versus 122 of 123; P = .00001). Among those who did drive, schizophrenic patients drove far less than controls (19 of 70 patients driving greater than or equal to 5,000 miles per year versus 81 of 122 controls; P = .0001). Patients also reported more accidents per miles driven than did controls, consistent with previous studies. Older patients reported more home accidents than did younger patients (five of eight for those over 55 years versus four of 95 for those less than 55; P = .0007); no similar effect was observed among controls. Schizophrenic outpatients may be at greater risk of motor vehicle accidents per miles driven than age matched controls; elderly patients may be at higher risk of home accidents as well.

Accident Proneness↗
PubMedDate not supplied

The effect of chronic cocaine exposure during pregnancy on maternal and infant outcomes in the rhesus monkey.

To explore the effects of gestational cocaine exposure in a nonhuman primate model, pregnant rhesus monkeys were treated from about 1 month of gestation until term with either 0 (N = 3), 0.3 (N = 3), 1.0 (N = 3), or escalating doses up to 8.5 (N = 3) mg/kg (IM), three times per day, 5 consecutive days per week. Despite these differences in cocaine exposure, the experimental groups did not differ significantly with respect to maternal outcome, as measured by body weight gain during pregnancy and length of pregnancy. A clear dose-response relationship was observed between the cumulative dose of cocaine administered during gestation and the levels of both cocaine and its major metabolite, benzoylecgonine, in samples of infant hair taken at birth. However, the experimental groups did not differ significantly with respect to infant outcome, as measured at birth by body weight, overall length, crown-to-rump length, rump-to-heel length, biparietal diameter, and crown circumference. Furthermore, the experimental groups did not differ significantly with respect to the integrity of a variety of infant reflexes tested at birth. It was concluded that, in a rhesus monkey model, chronic cocaine exposure during pregnancy had no significant effect on maternal and infant outcomes as assessed in this investigation.

Animals↗
PubMedDate not supplied

The effect of chronic cocaine exposure during pregnancy on the acquisition of operant behaviors by rhesus monkey offspring.

To explore possible long-term effects of gestational cocaine exposure in a nonhuman primate model, pregnant rhesus monkeys were treated from about 1 month of gestation until term with either 0 (N = 3), 0.3 (N = 3), 1.0 (N = 3), or escalating doses up to 8.5 (N = 3) mg/kg (IM), three times per day, 5 consecutive days per week. Despite these differences in cocaine exposure, the experimental groups did not differ significantly with respect to the postnatal growth of offspring over an 18-month period following birth. Beginning at 6 months of age, the behavior of offspring was monitored using an operant test battery that included five food-reinforced tasks designed to model aspects of learning, color and position discrimination, time estimation, short-term memory and attention, and motivation. Although the acquisition of each operant behavior by offspring progressed significantly during training between 6 and 18 months of age, this acquisition was not differentially affected by gestational cocaine exposure. It was concluded that, in a rhesus monkey model, chronic cocaine exposure during pregnancy had no significant effect on the offsprings' acquisition of operant behaviors.

Animals↗
PubMedDate not supplied

Transplacental pharmacokinetics of cocaine and benzoylecgonine in plasma and hair of rhesus monkeys.

There is large variability in the rate and extent of fetal damage from cocaine in humans; however, the sources of such variability are not presently known. In order to study the relationship between maternal cocaine pharmacokinetics at the end of pregnancy and maternal or infant cocaine and benzoylecgonine hair concentrations at birth, ten rhesus monkeys were administered cocaine intramuscularly throughout pregnancy. Cocaine and benzoylecgonine hair concentrations were determined at birth and correlated with maternal pharmacokinetics during pregnancy. There were no correlations between either maternal cocaine Cmax or AUC0-infinity and maternal and infant hair cocaine or benzoylecgonine concentrations. There were no significant correlations between maternal hair benzoylecgonine concentrations and either maternal benzoylecgonine AUC0-120 (r = 0.60; P = 0.07) or benzoylecgonine Cmax (r = 0.60; P = 0.07). No correlations existed between infant hair benzoylecgonine concentrations and either maternal benzoylecgonine AUC0-120 (r = 0.30; P = 0.40) or benzoylecgonine Cmax (r = 0.30; P = 0.40). Also, no correlation was found between maternal cocaine dose and maternal or infant cocaine and benzoylecgonine hair concentrations. In comparison to toxicants such as nicotine and carbon monoxide for which there is a good correlation between maternal systemic exposure and neonatal concentrations, the lack of a similar relationship for cocaine is consistent with the role of the placenta in contributing to the variability in the amounts of cocaine reaching the fetus and hence, potentially to the risk of adverse fetal outcome.

Animals↗
PubMedDate not supplied

The effect of chronic cocaine exposure throughout pregnancy on maternal and infant outcomes in the rhesus monkey.

To explore the effects of gestational cocaine exposure in a nonhuman primate model, pregnant rhesus monkeys were either treated (N = 10) with escalating doses of cocaine up to 7.5 mg/kg (IM), three times per day, 5 consecutive days per week, prior to conception and throughout gestation, or were not treated (N = 10) with cocaine at all. Substantial levels of both cocaine and its major metabolite, benzoylecgonine, were observed in samples of hair taken at birth from mothers and infants of the cocaine-treated group. Despite these differences in cocaine exposure, the experimental groups did not differ significantly with respect to maternal outcome, as measured by body weight again during pregnancy and length of pregnancy. On the other hand, the experimental groups did differ significantly with respect to infant outcome, as measured at birth by body weight, overall length, and crown circumference, all of which were decreased in the cocaine-treated group. A variety of reflexes tested at birth were normal in the cocaine-treated group. It was concluded that, in a rhesus monkey model, chronic cocaine exposure throughout pregnancy had no significant effect on maternal outcome, but did significantly affect infant outcome as assessed in this investigation.

Animals↗
PubMedDate not supplied

The gastric bypass operation reduces the progression and mortality of non-insulin-dependent diabetes mellitus.

Of 232 morbidly obese patients with non-insulin-dependent diabetes mellitus referred to East Carolina University between March 5, 1979, and January 1, 1994, 154 had a Roux-en-Y gastric bypass operation and 78 did not undergo surgery because of personal preference or their insurance company"s refusal to pay for the procedure. The surgical and the nonoperative (control) groups were comparable in terms of age, weight, body mass index, sex, and percentage with hypertension. The two groups were compared retrospectively to determine differences in survival and the need for medical management of their diabetes. Mean length of follow-up was 9 years in the surgical group and 6.2 years in the control group. The mean glucose levels in the surgical group fell from 187 mg/dl preoperatively and remained less than 140 mg/dl for up to 10 years of follow-up. The percentage of control subjects being treated with oral hypoglycemics or insulin increased from 56.4% at initial contact to 87.5% at last contact (P = 0.0003), whereas the percentage of surgical patients requiring medical management fell from 31.8% preoperatively to 8.6% at last contact (P = 0.0001). The mortality rate in the control group was 28% compared to 9% in the surgical group (including perioperative deaths). For every year of follow-up, patients in the control group had a 4.5% chance of dying vs. a 1.0% chance for those in the surgical group. The improvement in the mortality rate in the surgical group was primarily due to a decrease in the number of cardiovascular deaths.

Adult↗
PubMedDate not supplied

Plasma carbamazepine determinations: a simple gas chromatographic method.

1. A simple, rapid and specific gas chromatographic method for the measurement of plasma carbamazepine concentration is presented. 2. The extraction is a single step method, and the drug is measured by derivatization using on column methylation and standard instrumentation. 3. Other anticonvulsant agents do not co-extract. Other drugs do not interfere in the chromatogram. 4. Stability, recovery and reproducibility make this procedure suitable for routine carbamazepine measurements.

Carbamazepine↗
PubMedDate not supplied

Vrx: a verify-record system for radiotherapy.

A system of computer programs has been created to allow the entry of radiotherapy treatment details as defined by the physician, the verification of the machine parameters at every treatment, and the recording of the entire course of treatment. Various utility programs are available to simplify the use and maintenance of the system. The majority of the code is written in FORTRAN-77, the remainder in MACRO-11. The system has been implemented on a PDP 11/60 minicomputer for use with a Mevatron linear accelerator, the implementation required minor hardware changes to the accelerator.

Computers↗