Biomedical subjects

R C Green

Publications and source records attributed to R C Green.

At least 19 recordsLinked to original sources

PubMed1992

Treatment trial of oxiracetam in Alzheimer's disease.

Twenty-four carefully assessed patients with probable Alzheimer's disease were enrolled in a double-blind, placebo-controlled treatment study of oxiracetam, a nootropic agent reported to improve memory performance in patients with dementia. A broad battery of neuropsychological tests failed to reveal any improvement in the treated group or in any treated patient when individual test scores were analyzed. These findings indicate that oxiracetam is ineffective in reducing cognitive impairment due to Alzheimer's disease.

Aged↗

PubMed1992

Dysnomia in Alzheimer's disease: an evaluation of neurobehavioral subtypes.

The relative influence of perceptual and semantic features on naming performance was investigated with reference to the neurobehavioral profiles displayed by patients with Alzheimer's disease (AD). Forty-one patients were classified as manifesting a verbal, visual, or global subtype based upon their pattern of neuropsychological functioning. Perceptual characteristics of to-be-named pictures were varied by manipulating the amount of line detail, whereas semantic qualities were varied by altering word frequency norms. All AD subtypes were less accurate than normal elderly controls in naming low frequency pictures. Patients and controls took longer to name low frequency and high complexity pictures, and this effect was comparable across the AD groups. Patients with predominantly visual deficits were significantly slower in naming than controls, and those with verbal impairments made a higher proportion of semantic naming errors when compared to patients displaying visual or severe global impairments. These results suggest that deficits in semantic processing contribute to naming dysfunction in AD, and they highlight the importance of examining dissociations among neurobehavioral subtypes.

Alzheimer Disease↗

PubMed1992

Telephone fetal heart rate monitoring in South Australia.

A pilot trial was conducted to assess the technical feasibility of long range fetal heart monitoring by telephone in an Australian setting. The indications for such monitoring and patient ability and attitude towards self-monitoring was also assessed. One hundred and fifty seven tracings were received from 57 women using a simple doppler device to transmit fetal heart sounds to the central hospital fetal monitor. Thirty three of the patients were in country hospitals and 24 were at home. Gestation ranged from 26 to 42 weeks' gestation. Eighty six percent of the country hospital tracings and 94% of the home tracings were easily interpretable. The large majority of tracings were normal and appeared to encourage conservative management by the attendants. Two tracings were abnormal and these influenced early delivery in both cases. Nearly all women using the monitor at home found the procedure easy and reassuring. Tracings from country hospitals were initiated usually after an acute antenatal complication, whereas the indications for home-monitoring were prompted by longer-term, medium-risk factors. Home-monitoring may reduce the inconvenience and expense of inpatient or outpatient care and country hospitals without electronic fetal monitors may benefit from such a service. The selection of patients who might benefit from such technology remains controversial and warrants a prospective randomized controlled trial.

Cardiotocography↗

PubMed1990

Routine hospital admission in twin pregnancy between 26 and 30 weeks' gestation.

Of 141 women with twin pregnancies, 72 were randomly assigned to outpatient care and 69 to hospital admission between 26 and 30 weeks' gestation. There were no differences between the groups in the frequencies of major maternal complications in pregnancy and labour but more of those admitted to hospital than of the outpatient group had to be admitted after 30 weeks. There were no differences between the groups in the mean birthweights of the twins by birth order, or in their mean gestation at birth whether analysed by intention to treat or by the treatment given. 22 infants were delivered before 32 weeks' gestation in the inpatient group compared with 10 in the outpatient group. With the exception of small-for-dates infants, any trend towards greater morbidity or mortality was seen in the inpatient group. The policy of routine hospital admission of women with twin pregnancies from 26 weeks' gestation is not beneficial to mother or babies and should be abandoned.

Adult↗

PubMed1989

Alterations of hippocampal acetylcholinesterase in human temporal lobe epilepsy.

Hippocampal sclerosis is the most common pathological finding associated with human temporal lobe epilepsy. Histochemical study with acetylcholinesterase (AChE) staining was used to investigate 7 surgically resected temporal lobes with hippocampal sclerosis from patients with temporal lobe epilepsy. In all 7 specimens, an abnormal but consistent pattern of staining was noted. In the hilum of the dentate gyrus, AChE-rich polymorphic cells were relatively preserved in comparison to the pyramidal neurons. In Ammon's horn, AChE fibers were lost in regions corresponding to the pyramidal cell dropout. AChE fibers were also lost along the inner portion of the molecular layer of the dentate gyrus, yet they were preserved within the outer portions of the molecular layer. These findings provide additional evidence for the relative selectivity of hippocampal pathology in human temporal lobe epilepsy.

Acetylcholinesterase↗

PubMed1989

A non-stereotaxic method for olfactory bulb kindling reveals distinct kindling rates among inbred mouse strains.

A simple method for olfactory bulb kindling in the unrestrained mouse is described. Twisted wire electrodes attached to a dip-socket head assembly were implanted in the olfactory bulb. A ground lead was secured to a single skull screw and implantation was visually guided into the olfactory bulb. In all properly implanted preparations, stimulation produced an afterdischarge with behavioral responses which progressed to fully kindled convulsions. Location within the olfactory bulb did not affect the kindling rate. With this technique, mice from the C57BL/6J, C3H/He and DBA/2 inbred strains were kindled. Within each strain, kindling parameters were closely distributed about the group mean. Kindling rates in C3H and DBA inbred strains were significantly different from each other, but not significantly different from those reported in amygdala kindling.

Animals↗

PubMed1989

Muscle cell potassium, RNA and hydration in pregnancy and pre-eclampsia.

Thirty four pregnant women from 26 to 38 weeks gestation and 24 pregnant women with pre-eclampsia gave samples of muscle (rectus abdominis) at caesarean section. Muscle samples were analysed for H2O, K+, Mg2+ and Na+. Cell extracellular H2O was partitioned by the use of the Cl- space. Also protein, nucleic acids and Zn2+ were determined. From 26 to 38 weeks gestation the concentration of K+ per litre of cell water ([Ki]) slowly declined. The slope was significant. Points for patients with pre-eclampsia fell below the line and analysis of covariance showed that the two populations were different (P less than 0.001). Patients A-J were regarded clinically as severe pre-eclamptics. Points for these patients, in general, fell between 1 and 2 SDs below the normal line. Since other cations per litre of muscle cell water did not change, questions are raised. is the cation gap filled by amino acids or does vascular spasm cause a leakage of K+ from muscle cells? Does hypotonicity eventually develop leading to water intoxication? The low oncotic pressure in pre-eclampsia (shown here), the negative free water clearance could all favour increased cell hydration (some evidence for this is presented here towards term). Assessment of available information concerning creatinine excretion during normal pregnancy and K40, K42 studies together with our own rodent studies leads us to believe that a significant increase in muscle mass occurs, but such may not be the case in pre-eclampsia since the reduction in RNA and Zn2+ concentrations in muscle would suggest excessive protein degradation.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Muscles↗

PubMed1989

Malnutrition in aboriginal children at Yalata, South Australia.

Comparative studies of body weight, height, intracellular water representing cell mass, and age, and plasma concentrations of albumin, vitamins, trace elements and iron stores in Aboriginal children aged 6 to 13.5 years, from two rural Aboriginal settlements and one rural Caucasian school (Hawker) provided evidence of significant deficits in one of the Aboriginal settlements (Yalata). Yalata Aboriginal children had lower body weights and heights for age and lower intracellular water values. Plasma albumin, zinc, iron, alpha-tocopherol, beta-carotene and retinol concentrations were lower relative to the normally grown Aboriginal children at Nepabunna. The latter children did not differ from rural Caucasian children for the parameters studied. The reasons for this poorer growth at Yalata may reside in poor nutrition, or repeated bowel infection in postnatal life leading to malabsorption, or both. Limited observational evidence suggests that Giardiasis has a high prevalence at Yalata, and it has been shown elsewhere that Giardiasis is capable of inducing malabsorption with resulting nutritional deficiencies.

Adolescent↗

PubMed1988

Acetylcholinesterase fiber staining in the human hippocampus and parahippocampal gyrus.

The AChE fiber distribution within the human hippocampus and parahippocampal gyrus was studied in order to provide normative data for the examination of cholinergic fiberarchitecture in human pathology and to clarify the cytoarchitectonic organization of these structures. A modification of the Koelle method was used to stain temporal lobe serial sections from 6 neurologically normal human brains collected at autopsy. The hippocampal formation contains some of the densest staining of any cortical area. Regions with the heaviest concentrations of AChE fibers include a thin band along the inner edge of the molecular layer of the dentate gyrus (ml-DG) and parts of the CA2, CA3, and CA4 sectors of Ammon's horn. Staining is of intermediate intensity in the CA1 region. The subiculum (S) is more lightly stained than the CA fields. Staining in the parahippocampal gyrus is generally less dense than in the hippocampal formation. The most conspicuous feature of the human entorhinal cortex (EC) is the AChE-rich fiber patches seen overlapping the stellate cell islands in layer II. An additional band of relatively dense AChE staining is identified in layers IV-V. Prominent AChE-rich polymorphic neurons are present within the hilum of the dentate gyrus. The CA1/subiculum transition in Nissl preparation is characterized by an oblique interdigitation of CA1 cells. The transition from EC to prorhinal cortex occurs along the medial bank of the rhinal sulcus and is characterized by a band of AChE staining, which slopes obliquely away from layer II until it joins an intermediate pyramidal cell layer. Some comparisons with AChE staining in the monkey were made. The monkey has a similar pattern except in DG, where the intensely AChE staining band along the inner ml-DG is thicker and much more prominent. In comparison to the human, the monkey has more conspicuous AChE staining in the parasubicular region.

Acetylcholinesterase↗

PubMed1988

Epilepsy surgery in children.

Neurosurgical procedures of established value in the treatment of the medically intractable epilepsies include temporal lobectomy, extratemporal cortical excision, hemispherectomy, and corpus callosotomy. The clinical decision to consider surgery in children with epilepsy requires an understanding of the natural history of pediatric seizures, the constraints of the presurgical evaluation, and the relationship between surgical outcome and tissue pathology. This article presents an overview of the indications, risks, and benefits of epilepsy surgery in the pediatric population.

Cerebral Decortication↗

PubMed1987

Clinical comparison of Tourette's disorder and obsessive-compulsive disorder.

The authors report on 16 outpatients with Tourette's disorder, 16 outpatients with obsessive-compulsive disorder, and 16 normal control subjects who underwent structured interviews and psychological testing. Previous findings of a high incidence of obsessive-compulsive disorder in patients with Tourette's disorder were confirmed. There was a significantly greater incidence of tics in the patients with obsessive-compulsive disorder and their relatives. Both patient groups had high rates of unipolar depressive and generalized anxiety disorders. Panic and phobic disorders were frequent in the patients with obsessive-compulsive disorder but not in the patients with Tourette's disorder. The patients with obsessive-compulsive disorder showed less coprolalia, echo phenomena, self-destructive behavior, and childhood attention deficit.

Adult↗

PubMed1986

Serum relaxin in pregnancy.

Serum relaxin immunoactivity was measured by means of a porcine radioimmunoassay in a cross-sectional study of 302 normal singleton pregnancies. Concentrations in the third trimester were lower than in early and mid pregnancy. At term, relaxin levels in patients who went into spontaneous labour within a week of sampling were significantly lower than in those who did not. However, relaxin levels were highest during labour and fell almost to non-pregnant levels by the third postnatal day. Levels in twin pregnancies in the third trimester were higher than those in singleton pregnancies. Serial samples from 4 patients with a history of premature labour showed declining, very low levels in the only patient who subsequently had a preterm delivery. These results are compatible with the proposed roles of relaxin during pregnancy: namely, to maintain myometrial quiescence, facilitate uterine stromal remodelling during uterine growth, and promote cervical ripening at the onset of parturition.

Female↗

PubMed1986

Serum relaxin and pelvic pain of pregnancy.

Serum relaxin immunoreactivity was measured by means of a porcine relaxin radioimmunoassay in 35 patients with severe pelvic pain and pelvic joint instability during late pregnancy. Results were compared with a control group of 368 samples obtained throughout pregnancy from normal singleton pregnancies. Most of the relaxin concentrations in the study group were above the 95% confidence limits of the median for the corresponding gestational age in the control group. The difference in relaxin levels between the study and control groups in the third trimester was highly significant. Relaxin levels in patients with pelvic pain were close to normal non-pregnant levels by the third postnatal day. The highest relaxin levels during pregnancy were found in the patients who were the most incapacitated clinically. The results suggest that there may be an association between high serum relaxin levels and pelvic pain and joint laxity during late pregnancy.

Female↗

PubMed1986

Systematic regional differences in the cholinergic innervation of the primate cerebral cortex: distribution of enzyme activities and some behavioral implications.

Choline acetyltransferase and acetylcholinesterase enzymatic activities were measured in 33 cytoarchitectonic subregions of the cerebral cortex in two rhesus monkeys. As expected, the hippocampus and amygdala were rich in these enzymes. In addition, the paralimbic (mesocortical) regions of the brain (e.g., parahippocampal, insular, caudal orbitofrontal, and temporopolar areas) also contained high levels of both enzymes. In contrast, the concentration of these cholinergic markers was the lowest within all frontal and temporoparietal association areas. As a group, the primary sensory and motor regions contained an intermediate level of choline acetyltransferase activity. Both cholinergic markers also showed a gradual increase from the isocortical toward the more primitive periallocortical subsectors of paralimbic areas. These anatomical patterns have potential implications for the role of cholinergic pathways in the memory process and in the pathogenesis of Alzheimer's disease.

Acetylcholinesterase↗

PubMed1986

Ripening of the human cervix and induction of labor with intracervical purified porcine relaxin.

In a randomized double-blind placebo-controlled trial involving 71 patients, a viscous gel containing distilled water or 1 or 2 mg pure porcine relaxin was instilled in the cervical canal on the evening before the surgical induction of labor. Eleven of 48 patients receiving relaxin labored overnight, whereas only one of 23 patients went into labor. Only the 2-mg dose significantly improved the mean cervical score compared with the placebo treatment; the effect was greatest in primigravid patients with unripe cervixes. Intracervical application appeared to confer no benefit over vaginal application in effecting cervical ripening or inducing labor. Systemic absorption of the porcine relaxin after its intracervical application was confirmed by the measurement of immunoreactive relaxin in a homologous porcine relaxin radioimmunoassay. Thus, the cervical ripening effect of exogenous relaxin may be mediated either systemically or by direct action at the site of local application. This trial confirms the responsiveness of the human term cervix to exogenous relaxin and supports the suggestion that endogenous relaxin may play a similar role at term in facilitating cervical ripening and parturition.

Administration, Intravaginal↗

PubMed1985

Muscle cell growth and the distribution of water and electrolyte in human pregnancy.

Ten normal pregnant women had muscle composition analyses (rectus abdominis) carried out at 39-40 weeks of pregnancy. Water, chloride (Cl), chloride space (ECV), non-chloride space (ICW), potassium (K), sodium (Na), magnesium (Mg) and zinc (Zn) determinations were carried out. Analyses for DNA (cell number), protein: DNA ratio (cell size), RNA and collagen were also performed. Similar analyses were performed on uterine muscle and placentae before and after perfusion with Earle's solution. Data from pregnant patients were compared with similar estimations carried out on rectus abdominis samples from 13 non-pregnant subjects undergoing gynaecological procedures. Muscle tissue and predicted muscle mass (MM) (which constitutes 40% of body weight) demonstrated that the gain in body K was due to the products of conception, that ICW decreased per unit weight in muscle (8%), ECV increased (41%) without a radical change in muscle water content (2%). Overall a 6 l gain in ECV and a 2 l gain in ICW can be accounted for during pregnancy. The results of this study indicate that added hydration excluding the products of conception (placenta, infant, uterus) is mainly extracellular. Intracellular Na concentration decreases (50%) and it is speculated that the cation gap is made up by H+ in the presence of extracellular alkalosis. Muscle cells diminish in size but cell number per gram is constant. Zinc content (Zn/DNA) decreases. Previous experimental work suggests that MM increases by about 10% during pregnancy and this information has been included in considerations but it remains to be shown to what extent total muscle cell numbers increase and as to whether such increased muscle growth remains following pregnancy.

Cell Division↗

PubMed1979

Cervical ripening and induction of labour with intravaginal prostaglandin F2 alpha.

A randomised double-blind trial was done to determine the effect on cervical ripening of 50 mg intravaginal prostaglandin F2 alpha (P.G.F.2 alpha) in a methyl cellulose gel given on the evening before surgical induction of labour. Patients were given either placebo or P.G.F.2 alpha and in both groups cervical stretching and sweeping of the fetal membranes was attempted. Of the 40 control patients, 3 had gone into labour and the mean improvement in the cervical score was 1.6 before surgical induction the next morning. However, 20 of the 40 patients receiving P.G.F.2 alpha went into labour before the proposed induction and the mean change in cervical score (5.1) was significantly greater than that in the placebo group. Of the 40 patients pretreated with P.G.F.2 alpha, 37 had improved cervical scores and significantly fewer required augmentation in labour with intravenous oxytocin than in the control group. No side-effects were experienced and the patients found the treatment acceptable.

Cellulose↗

PubMed1979

Fetal heart rate monitoring during ambulant labour using a modified adult radiotelemetry system.

A commercially available adult radiotelemetry system has been adapted successfully to allow continuous fetal heart rate monitoring during labour in ambulant patients. The modifications necessary to the adult equipment and its routine use in a large maternity unit are described. High quality recordings were obtained from 90% of the patients studied, with minimal inconvenience to the patient. The telemetry system combined the benefits of intrapartum fetal heart rate monitoring with those of ambulation during labour, decreasing the patient anxiety often associated with visible fetal monitoring.

Ambulatory Care↗