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Biomedical subjects

L Patterson

Publications and source records attributed to L Patterson.

At least 37 records · Page 2Linked to original sources
PubMed1993

Magnetic resonance spectroscopy in social phobia: preliminary findings.

Proton localized magnetic resonance spectroscopy was studied in 20 social phobics and 20 age- and sex-matched controls. Stimulated Echo Acquisition Mode volume element localization was used with chemical shift imaging. Choline and creatine signal-to-noise ratios (SNRs) were significantly lower in social phobia than in controls in subcortical, thalamic, and caudate areas. In the social phobic group, N-acetylaspartate (NAA) SNR was significantly lower in cortical and subcortical regions, and ratios of NAA to other metabolites were lower in social phobia. Choline, creatine, and NAA SNRs were inversely correlated to total social phobia and fear symptoms, as measured by the Brief Social Phobia Scale, in the thalamic and noncortical gray areas. In a small number of patients who received clonazepam, posttreatment SNRs generally increased relative to baseline. Our results suggest a promising place for magnetic resonance spectroscopy in social phobia and also indicate potential pharmacodynamic uses of this technique.

Adult↗
PubMed1992

A randomized double-blind study of neuroelectric therapy in opiate and cocaine detoxification.

Prior research on the use of transcranial neuroelectric stimulation suggested that the application of low-amperage, low-frequency alternating current via surface electrodes placed in the mastoid region could relieve the physiological signs and subjective symptoms of withdrawal and craving during opiate detoxification. These effects were reported without gradual tapering of the opiate or the addition of other medications. To test the efficacy of one particular form of neuroelectric therapy (NET), a double-blind, randomized, placebo-controlled study was conducted comparing active NET and placebo NET in the treatment of withdrawal and stabilization of 18 opiate-dependent and 25 cocaine-dependent subjects. Scores on scales for measuring substance withdrawal and craving for each abused substance, as well as the multiple dimensions of mood, were compared for degree of difference across the 10 days of treatment. There was an overall completion rate of 88%, with both cocaine and opiate groups reporting a comfortable detoxification and substantial improvement over the course of a 12-day hospitalization. There was no significant difference between the active or placebo groups, suggesting that placebo was as effective as active NET in reducing drug withdrawal or craving during cocaine and opiate detoxification. However, all placebo patients received 0.2 mA of current, which may have provided a degree of active current. Suggestions are offered for future research.

Adult↗
PubMed1992

Effects of dietary fat on cholesterol movement between tissues in CBA/J and C57BR/cdJ mice.

Differences in dietary fats cause differences in cholesterol metabolism in mice. CBA/J mice are resistant to diet-induced hypercholesterolemia and atherosclerosis; they adjust hepatic hydroxymethyl-glutaryl-CoA reductase activity (HMGR) to maintain homeostasis; C57BR/cdJ mice are susceptible, but young animals are thought to maintain homeostasis by changing fecal excretion of sterols. Compartmental modelling of movement of [4-14C]cholesterol was used to analyze movement of cholesterol between serum and liver, heart, and carcass in mice fed 40 en% fat, polyunsaturated to saturated fatty acid ratio (P/S) = 0.24 (US74) or 30 en% fat, P/S = 1 (MOD). Dietary effects were quite pronounced, while strain effects were more subdued. The C57/cdJ animals appear to regulate the overall cholesterol balance by reducing synthesis, as do the CBA/J animals, even though synthesis is not reduced to the same degree as in the CBA/J animals. Both diet and strain influence the whole-animal turnover rate, with slower turnover occurring for C57BR/cdJ animals and animals fed the US74 diet.

Animals↗
PubMed1991

The influence of maternal undernutrition in ovine twin pregnancy on fetal growth and Doppler flow-velocity waveforms.

The effects on placental blood flow velocity of maternal undernutrition during mid pregnancy were investigated in 38 twin bearing pregnant sheep by Doppler analysis of umbilical and uteroplacental arterial waveforms. Mid pregnancy undernutrition resulted in fetal growth restriction manifest at term gestation by reduced mean birth weight. Arterial waveform systolic/diastolic ratios from the umbilical and uteroplacental arterial circulations were not influenced by maternal nutrition either during the dietary deprivation or during a subsequent period of dietary supplementation. An effect of heart rate on systolic/diastolic ratios could not be demonstrated. The results indicate that the fetus responds to mid pregnancy maternal undernutrition with restricted growth but without alterations in systolic/diastolic ratios in umbilical or uteroplacental arterial waveforms.

Animals↗
PubMed1990

Effects of maternal cigarette smoking on ultrasonic measurements of fetal growth and on Doppler flow velocity waveforms.

Serial ultrasound biometry and Doppler flow velocity waveform analysis were used to measure the effects of maternal smoking in a prospective study of 535 pregnancies. Smoking was associated with significant reductions in maternal weight gain, birthweights and placental weights. Decreased fetal biparietal diameter measurements were observed in pregnancies of smoking women; this effect was maximal at 24 weeks' gestation, was restricted to male fetuses and was not associated with altered head circumferences after birth. Umbilical artery and uteroplacental systolic/diastolic ratios were similar in pregnancies of smoking and non-smoking women, indicating that the effects of smoking on placental vascular resistance are periodic rather than continuous. The findings of this study confirm the need for studies of fetal growth to include prenatal measurements obtained by high resolution ultrasound imaging, rather than relying on findings obtainable by examination of the infant after birth.

Adult↗
PubMed1990

The effect of heart rate on Doppler flow velocity systolic-diastolic ratios in umbilical and uteroplacental arterial waveforms.

In an analysis of the influence of heart rate on Doppler flow velocity waveform-systolic/diastolic ratios from 1555 umbilical artery waveform studies and from 1497 uteroplacental waveform studies, a negative correlation was observed between the ratio and the corresponding heart rate. This relationship was not influenced by gestational age and was similar in pregnancies with normal outcomes when compared with all pregnancies. The magnitude of this inverse relationship is such that the effect of heart rate on systolic/diastolic ratios must be considered when Doppler flow velocity waveform analyses are used as experimental tools to assess placental vascular resistance but it does not appear to be an important factor in general clinical practice when measurements are made during fetal inactivity and when heart rates are within normal ranges.

Blood Pressure↗
PubMed1990

Transrectal ultrasonography in the evaluation of the infertile man: a report of 3 cases.

The traditional evaluation of the infertile man with azoospermia or low ejaculate volume includes determination of serum testosterone and follicle-stimulating hormone levels, a seminal fructose test, post-ejaculate urinalysis and, sometimes, vasography. Transrectal ultrasonography, a technique currently familiar to most urologists, recently has been added to our diagnostic armamentarium. This office-based imaging procedure provides an accurate assessment of the prostate, ejaculatory ducts and seminal vesicles, which can be helpful in the evaluation of certain infertile patients. We describe 3 patients who presented with either azoospermia or decreased ejaculate volume in whom transrectal ultrasonography had a critical role in the fertility evaluation. The clinical indications for and interpretation of transrectal ultrasonography in the infertile population are described. Transrectal ultrasonography currently is the most accurate, inexpensive and readily available noninvasive imaging technique used to diagnose obstruction of the ejaculatory ducts in the infertile patient with either azoospermia or low ejaculate volume.

Adult↗
PubMed1987

The sensitivity of radionuclide and thermodilution techniques to detect cardiac dysfunction in the baboon model during prolonged anaesthesia.

This study was undertaken to evaluate the fluctuations of cardiac parameters in a baboon model during pentobarbitone anaesthesia which will serve as a baseline control for shock studies. Thermodilution and radionuclide methods were used to determine cardiac parameters. Radionuclide studies were repeated without any cardiac catheters to assess the effect of these on cardiac performance. The results represent baseline fluctuations in cardiac parameters against which cardiac dysfunction can be diagnosed in shock studies. The results also indicate that cardiac catheterisation does not affect cardiac performance significantly.

Anesthesia, Intravenous↗
PubMed1984

Management of pain in sickle cell disease using biofeedback therapy: a preliminary study.

Fifteen patients with a history of painful episodes of sickle cell disease were given training in progressive relaxation, thermal biofeedback, cognitive strategies, and self-hypnosis to help them develop self-management skills to relieve pain. Results show a 38.5% reduction in the number of emergency room visits, a 31% reduction in the number of hospitalizations, and a 50% reduction in the inpatient stay during the 6 months since the beginning of therapy compared to 6 months prior to therapy. Analgesic intake was reduced by 29% for those who were using it regularly. This is a preliminary study, and the results are considered only as suggestive of the potential use of biofeedback therapy and behavioral management in alleviating painful episodes in sickle cell disease.

Adult↗
PubMed1982

Arcus senilis: an important forensic physical finding.

Arcus senilis is a deposition of lipid at the corneal periphery. It is dependent on vascularity for formation and is not a degenerative change. The prevalence of arcus increases with age, and it appears more in blacks and males. It appears to be related to cardiovascular disease but has not been shown to be a reliable predictor of the disease. We studied the incidence of arcus width with age and found no definite correlation.

Adolescent↗
PubMed1980

The effectiveness of group psychotherapy during the first three weeks of hospitalization. A controlled study.

Insight-oriented group psychotherapy is a common modality of treatment on inpatient psychiatric wards, yet is effectiveness for acutely hospitalized patients has not been adequately studied. A comparison was made of the effects of three experimental conditions (insight-oriented group psychotherapy, activity-oriented task group, and unstructured control condition) on 86 acutely hospitalized psychiatric patients at a United States Air Force teaching hospital. The group psychotherapy and task group patients did not show greater improvement after 20 days of hospitalization than control patients. In fact, significantly more psychotic patients scored worse in the group psychotherapy condition. It is suggested that insight-oriented group psychotherapy may not be an effective treatment modality during the first 3 weeks of psychiatric hospitalization, especially for psychotic patients.

Adolescent↗
PubMed1977

The pH of brain extracellular fluid in the cat.

1. The blood supply to the medulla was determined by the injection of indian ink via the vertebral arteries. Virtually the whole medulla was supplied by penetrating vessels from the ventral surface. The highest density of small arterioles and venules was found close to the roots of XII and on the ventrolateral surface.2. The pH of extracellular fluid (pH(e.c.f.)) was measured with pH microelectrodes of tip size 1-3 mum in cortex and medulla in seventeen cats, anaesthetized with pentobarbitone or a chloralose-urethane mixture. Parallel measurements were made of the pH of c.s.f. and plasma, the DC potential between plasma and brain and ventilation or phrenic nerve discharge.3. In the majority of tests under steady conditions, the pH of e.c.f. was found to be lower than that of c.s.f. by between 0.03 and 0.08 units. No systematic pH gradients could be found to a depth of 5 mm beneath the surface of either medulla or cortex.4. When plasma P(CO2) was altered, pH(e.c.f.) changed with a latent period and speed of response related to the density of blood vessels. In vascular areas of the medulla and in the cortex, the latent period of 4 sec and the change of pH(e.c.f.) coincided with changes in ventilation. Changes in pH(c.s.f.) over the same areas were invariably slower.5. CO(2) buffering capacities were in the order plasma > e.c.f. > c.s.f. Typical values were respectively, -2.2, -2.1 and -1.6.6. The pH of e.c.f. was unaffected by the intravenous injection of H+ and only slowly by the injection of HCO(3)-. Only up to a depth of 1 mm beneath the surface was pH(e.c.f.) affected by superfusion of mock c.s.f. in the range 6.8-8.0 units. This response had a latent period of 2-3 min and was complete in 15 min.7. The pH of e.c.f. fell with hypoxia after a latent period of > 1 min and if all vasosensory nerves had been cut, pH(e.c.f.) was markedly affected by changes of blood pressure.8. These results indicate that even under steady conditions, the pH of e.c.f. and c.s.f. is not identical, that pH(e.c.f.) is more obviously affected by changes in P(a, CO2) than pH(c.s.f.) and that putative H+ sensors which drive respiratory neurones are likely to be similarly affected.

Animals↗
PubMedDate not supplied

Infantile hypertrophic pyloric stenosis after pertussis prophylaxis with erythromcyin: a case review and cohort study.

BACKGROUND: In February, 1999, a local US health department identified a cluster of pertussis cases among neonates born at a community hospital and recommended oral erythromycin for post-exposure prophylaxis for about 200 neonates born at that hospital between Feb 1 and Feb 24, 1999. We investigated a cluster of seven cases of infantile hypertrophic pyloric stenosis (IHPS) that occurred the following month among the neonates who had received erythromycin. METHODS: We obtained a masked, independent review of the IHPS ultrasonography diagnoses, calculated the monthly IHPS incidence, and compared index and historical (1998-99) IHPS cases with respect to several characteristics including erythromycin exposure. We used a retrospective cohort of infants born in January and February, 1999, to investigate further erythromycin exposure and development of IHPS. FINDINGS: An independent review confirmed the ultrasonographic diagnoses of all seven index IHPS cases. All index cases versus none of the historical IHPS cases had been given erythromycin for pertussis prophylaxis. The IHPS rate for infants born in the hospital in February, 1999, was 32.3 per 1000 liveborn infants, representing nearly a seven-fold increase over 1997-98 (relative risk 6.8 [95% CI 3.0-15.7]). Among infants born in January and February, 1999, erythromycin was associated with IHPS (absolute risk 4.5%, relative risk infinity [1.7-infinity]). INTERPRETATION: Neonates receiving oral erythromycin may have an increased risk of IHPS. The risks and benefits of erythromycin for neonatal pertussis prophylaxis should be re-evaluated, and caution should be used in defining risk groups for prophylaxis.

Administration, Oral↗