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Biomedical subjects

C Harper

Publications and source records attributed to C Harper.

At least 73 records · Page 4Linked to original sources
PubMed1990

Nasopharyngeal teratoma ('hairy polyp'), Dandy-Walker malformation, diaphragmatic hernia, and other anomalies in a female infant.

Nasopharyngeal teratomas are rare and are infrequently associated with extra-oral malformations. The case of a premature female infant with multiple congenital anomalies, including nasopharyngeal teratoma, Dandy-Walker malformation, diaphragmatic hernia, and congenital heart defect, is presented. This constellation of malformations does not appear to have been reported previously.

Abnormalities, Multiple↗
PubMed1990

Changes in the basal dendrites of cortical pyramidal cells from alcoholic patients--a quantitative Golgi study.

Although a variety of pathological changes have been described in the brains of chronic alcoholic patients, there have been no studies which have addressed the question of alterations in cortical neuronal dendritic arborisation. Loss of neurons from the superior frontal gyrus and shrinkage of neurons from both the superior frontal gyrus and motor cortex has been documented in chronic alcoholic patients; these areas were chosen for this study. Using a modified rapid Golgi technique the basal dendritic arborisation of layer III pyramidal neurons was compared in 15 male alcoholic patients and 15 age-matched male controls. All parameters measuring basal dendritic arborisation were significantly less in the alcoholic cases for both the superior frontal and motor cortices. Changes in the arbor are in the terminal branches, which is consistent with other models of dendritic plasticity. Such changes may explain both permanent and reversible functional deficits in chronic alcoholic patients.

Alcoholism↗
PubMed1989

Morphometric study on the postnatal growth of the cerebellum of Australian aborigines and Caucasians.

In an autopsy study on 29 male Aborigines and 57 male Caucasians, macroscopic and microscopic parameters of postnatal cerebellar development were determined and described by mathematic growth functions. For the whole cerebellum and its cortical layers volume measurements revealed delayed maturation for Aborigines compared to Caucasians. Despite the slower development in childhood, significantly smaller values for adult Aborigines compared to Caucasians were observed only for the whole cerebellum and the Purkinje cell sheet. Similarly, postnatal changes in Purkinje cell size showed prolonged growth phases in Aborigines compared to Caucasians. Calculations of absolute cell numbers for individual layers demonstrated later half-value times and slower growth rates for cell numbers in the internal granular and molecular layers consistent with the findings for the corresponding layer volumes. For Caucasians, the growth curve for the absolute cell number in the internal granular layer showed a maximum about 21 months postnatally and subsequently decreased towards adulthood by about 18%. No such overshoot could be demonstrated for Aborigines. In relation to absolute cell numbers in adulthood, this could indicate a smaller number of granule cells migrating from the external to the internal granular layer as well as less pronounced granule cell death in Aborigines compared to Caucasians. The external granular layer of Caucasians increased in volume postnatally to reach a maximum at about 4 months and subsequently decreased until its disappearance at approximately 2 years of age. The number Purkinje cells decreased marginally postnatally in both populations. These results were discussed in relation to secular changes of growth parameters of the cerebellum during the last century and the socioeconomic and health status of Aborigines.

Adolescent↗
PubMed1989

Effects of Na saccharin feeding and urine on barrier properties of excised rat urinary bladder.

When male rats of certain strains are fed a diet with 3% or more Na saccharin, their urinary bladders develop epithelial hyperplasia and a greater incidence of tumors. Since the daily dose of saccharin is high, a link between tumor formation and the disruption of urothelial physiologic and biochemical processes has been sought. We fed male and female Sprague-Dawley rats a saccharin-free or 7.5% Na saccharin diet for 1 month. Excised bladders were mounted in flux chambers and exposed to Krebs-Ringer bicarbonate solution (KRB) or urine. Bioelectric properties and 22Na, 36Cl, and [14C]mannitol or [3H]mannitol unidirectional fluxes were measured by conventional techniques. No differences were noted between bladders from male and female animals or between Na saccharin-fed animals and animals fed the saccharin-free diet. When both surfaces of the epithelium were exposed to KRB, transepithelial dc conductance fell over 4 hr to 50% of the initial value. Conductance averaged 1.4 mS/cm2. Transepithelial potential difference (PD) was usually lumen negative and averaged 0.7 mV. Unidirectional permeability coefficients for 36Cl, 22Na, and radiomannitol were symmetric, proportional to conductance, and followed a rank order compatible with unrestricted passive diffusion. Exposure of the bladder lumen to urine from animals fed saccharin-free or Na saccharin diet hyperpolarized the transepithelial PD by more than 5 mV and raised conductance nearly threefold. Permeability coefficients remained symmetric and compatible with passive diffusion. Exposure of the lumen to solutions with the K+, Na+, and Cl concentrations and osmolality of urine simulated the conductance and PD effects of urine. We conclude that Na saccharin feeding or urine with saccharin does not uniquely affect the permeability of the excised preparation. Small hydrophilic solutes appear to cross the bladder epithelium through paracellular channels which increase in aggregate area during exposure of the lumen to urine. The hyperpolarization induced by lumenal urine is the consequence of the transepithelial K+ gradient.

Animals↗
PubMed1989

Morphometric study on the postnatal growth of non-cortical brain regions in Australian aborigines and Caucasians.

In an autopsy study on 29 male and 27 female Aborigines and 57 male and 37 female Caucasians the volumes of a large number of brain regions were determined and fitted to logistic growth functions. For Aboriginal adults significantly smaller values were found for weight and volume of the whole brain, cerebrum, and cerebellum and for the volumes of cerebral white matter, thalamus, amygdaloid body (females only), and globus pallidus (males only). No significant differences were found for caudate nucleus, putamen, amygdaloid body (males only), and globus pallidus (females only). Almost every region studied showed later half-value times, slower growth rates, and prolonged growth phases for Aborigines compared to Caucasians. These results are discussed in relation to secular changes of growth parameters of the human brain during the last century, timing of growth phases for each area, and the socioeconomical and health status of Aborigines.

Adolescent↗
PubMed1989

Patterns of neuronal loss in the cerebral cortex in chronic alcoholic patients.

A loss of neurones from the frontal cortex of chronic alcoholic patients has recently been documented. In addition to this loss of neurones there was found to be a reduction in the mean size of the neuronal soma in both the superior frontal and motor cortices. This could be explained on the basis of a selective loss of larger neurones rather than a general shrinkage of all neurones. This population of large neurones (greater than 90 microns 2) has been recognised as being more vulnerable in both Alzheimer's disease and the normal ageing process. Neurones in 2 size categories (41-90 microns 2 and greater than 90 microns 2) were counted in the superior frontal and motor cortices of age- and sex-matched controls and alcoholics. There was found to be a significant reduction in the number of large neurones in the superior frontal cortex, whilst no change in number was seen in the motor cortex. The possibility that neurones in particular layers of the cortex are more severely affected in alcohol abuse was also considered. The cortex was divided into 3 layers and the number of neurones and glia in each determined. No pattern of regional neuronal loss could be distinguished.

Alcoholism↗
PubMed1989

Clinical aspects of pneumonia in the elderly veteran.

While atypical presentation of pneumonia in elderly patients is thought to be common, its incidence and factors predisposing to it are unknown. This study documents presenting symptoms of pneumonia in 48 patients, aged 65 or older, admitted to the medical service at a Veterans Administration Medical Center. Seventeen subjects (35%) had a classic constellation of symptoms which included both fever and cough. A chief complaint suggestive of pneumonia, defined as cough, fever, or shortness of breath, occurred in 27 subjects (56%). Five subjects (10%) had no symptoms suggestive of pneumonia even with a detailed history. Absence of a classic constellation of pneumonia symptoms correlated with advanced age (P = .0045), cognitive impairment at admission (P = .022), and baseline functional impairment (P = .028). Neither nutritional status as measured by serum albumin nor medical status as measured by number of medical problems and number of medications predicted an atypical presentation of pneumonia. Nineteen subjects (39%) did not have a documented fever, and 15 subjects (31%) did not have a leukocytosis. Absence of fever or leukocytosis did not correlate with age, number of medical problems, number of medications, cognitive status, functional status, or serum albumin. We conclude that a classic constellation of symptoms, signs and laboratory findings is frequently absent but some suggestive symptom is usually present in this population of elderly veterans with community-acquired pneumonia. Patients with advanced age, cognitive impairment at admission, and baseline functional impairment are most likely to have an atypical presentation of pneumonia.

Aged↗
PubMed1989

The prevalence of the Wernicke-Korsakoff syndrome in Sydney, Australia: a prospective necropsy study.

In a prospective necropsy study, the prevalence of the Wernicke-Korsakoff syndrome (WKS) in Sydney, Australia was 2.1% of adults over the age of 15 years. The population studied encompassed a wide spectrum of socio-economic and cultural backgrounds. Abuse of alcohol appeared to be the major predisposing factor to the development of the WKS in cases which were adequately documented. This high prevalence rate is in line with other clinical and pathological Australian studies and provides additional support for the idea of prevention of the WKS by the use of thiamin supplements in the Australian diet in flour, bread and perhaps alcoholic beverages.

Adolescent↗
PubMed1988

Diagnostic clues in an adult case of Leigh's disease.

A previously-well 32-year-old woman presented with episodes of severe headache, neck pain, numbness of the tongue and facial sweating. In the course of her illness she became abulic, blind and quadriparetic and she suffered recurrent episodes of coma during which she became decerebrate and her brain-stem reflexes were absent. She had an adult form of Leigh's disease, which is an extremely-rare degenerative condition of unknown cause. The clinical, neuroradiological and neuropathological features are presented.

Adult↗
PubMed1988

Does a "moderate" alcohol intake damage the brain?

A range of volumetric and neurochemical analyses were carried out on the brains of 14 "moderate" drinkers. These data were compared with previous studies from controls and alcoholics. Volumetric measurements consistently suggest a loss of cerebral tissue although the differences were not statistically significant. Changes in the lipid and water content of the white matter were noted and the significance of these changes in relation to the pathogenesis of reversible brain shrinkage caused by alcohol abuse is discussed.

Alcohol Drinking↗
PubMed1987

Capillary gas chromatographic-electron capture detection of coca-leaf-related impurities in illicit cocaine: 2,4-diphenylcyclobutane-1,3-dicarboxylic acids, 1,4-diphenylcyclobutane-2,3-dicarboxylic acids and their alkaloidal precursors, the truxillines.

A method has been developed that allows for the detection of the eleven stereoisomers of diphenylcyclobutanedicarboxylic acid in illicit cocaine samples, including alpha-, gamma-, and epsilon-truxillic acids and beta- and delta-truxinic acids. These, and other carboxylic acids, were also detected as ester moieties of alkaloidal impurities in illicit cocaine as well as in alkaloids of the South American coca leaf, e.g., alpha- and beta-truxilline. After lithium aluminum hydride reduction of the acidic and basic extracts of a prepared sample, the reduced species were derivatized with heptafluorobutyric anhydride in the presence of pyridine. The heptafluorobutyryl derivatives of the reduced diphenylcyclobutanedicarboxylic compounds were easily detected on-column at low picogram levels using a moderately polar fused-silica capillary column in the splitless mode and interfaced with a 63Ni electron-capture detector.

Alcohols↗
PubMed1987

Are we drinking our neurones away?

A quantitative neuropathological necropsy study of the human cerebral cortex showed that the number of cortical neurones in the superior frontal cortex in chronic alcoholic patients is significantly reduced compared with that in controls matched for age and sex. The number of neurones in the motor cortex did not differ significantly between the controls and alcoholics, but in both cortical regions there was evidence that alcoholic patients had smaller (shrunken) neurones than controls. Further studies are necessary to identify other regions of the cerebral cortex that are selectively damaged in brain damage associated with alcohol.

Adult↗
PubMed1987

Methotrexate-induced changes in rat parotid and submandibular gland function.

Methotrexate (MTX) was injected intraperitoneally at a dose of 15 mg/kg into adult rats daily for three consecutive days. When compared with saline-injected, ad libitum-fed rats or pair-fed saline-injected rats, MTX decreased unstimulated parotid gland weight, RNA content, and amylase content. RNA content was also decreased in submandibular glands. The parotid and submandibular gland outputs of sodium and chloride, but not that of potassium, were decreased following MTX injection. Ductal perfusion demonstrated decreased net efflux of sodium and chloride from the excretory duct of the submandibular gland. The effects of MTX on unstimulated parotid gland weight, RNA content, and amylase content are consistent with its ability to inhibit protein synthesis through depletion of folate co-factors. However, the mechanism by which the alterations in ion transport occurred is not clear at this time.

Animals↗
PubMed1987

The morphology of Australian aboriginal brains--documentation of eight cases.

Cortical morphology of the brains of eight Western Australian Aboriginals was documented. Sulcal patterns permitted classification of the brains into separate groups. Characteristic patterns were found for the shape of the prosencephalon and for the insular, parietooccipital, and frontal cortex in the aboriginal group. The length of the frontal, parietal, and occipital lobes and the width of the temporal lobes was measured. Length, width, and height of the Aboriginal prosencephalons were compared to measurements of eleven Caucasian brains. Postmortem changes, genetic differences, and factors influencing brain development were discussed.

Adult↗
PubMed1987

A quantitative study of Australian aboriginal and Caucasian brains.

The brain volumes of 8 male Australian Aborigines and 11 male Caucasians were determined. Total brain volume was significantly smaller for Aborigines (1199 +/- 84 ml) compared to Caucasians (1386 +/- 98 ml). Significantly smaller volumes were also found for cerebellum, prosencephalon-mesencephalon unit, cerebral cortex, frontal cortex, parieto-occipitotemporal cortex, and hippocampus. Volumes of ponsmedulla oblongata unit (21 +/- 3 ml for Aborigines and 22 +/- 3 ml for Caucasians) and visual cortex (14.9 ml +/- 2.6 ml and 14.6 +/- 2.2 ml, respectively) did not differ significantly. The striate cortex extended further onto the lateral surface of the occipital lobe in Aboriginal brains. The frontal portion of cerebral cortex was larger in Aboriginal than in Caucasian brains. According to the specific growth periods for the areas studied, these differences could be explained by the higher incidence of malnutrition and infectious diseases for Aboriginals during the development of the brain in early childhood, especially after the 6th postnatal month. However, genetic influences cannot be excluded. The results for the visual cortex of Aborigines might represent an adaptation to living conditions in the bush and desert regions of Australia.

Adult↗
PubMed1986

The effect of alpha-interferon, cyclosporine A, and radiation-induced immune suppression on morphine-induced hypothermia and tolerance.

An interconnection between the immune and the central nervous systems has been suggested by investigators studying the actions of several types of immune modifying agents and procedures upon opiate related phenomena. These studies have included the effects of altering immune system function by administration of either alpha-interferon, cyclosporine or radiation exposure upon naloxone-precipitated opiate withdrawal and upon opioid antinociceptive effects. The present study extends these earlier investigations by examining the effect of immune modulation upon opiate induced hypothermia. The results demonstrate that interferon and cyclosporine have no effects on baseline temperature or morphine induced hypothermia, while irradiation exposure elicits hyperthermia without affecting morphine-induced hypothermia. Finally, neither cyclosporine nor irradiation affect the development of tolerance to morphine induced hypothermia, while a single injection of the immune system modifier interferon was able to prevent the development of such tolerance. These observations suggest that yet another opiate-related phenomenon may be regulated at least in part by the immune system. These results together with our previous findings are further evidence of a link between the immune system and the CNS mediated through the opioid system. In addition, these studies further support our earlier hypothesis that "Interferon" is one of the endogenous substances which serves to prevent the development of tolerance and dependence to endogenous opioids.

Animals↗
PubMed1986

Suppression of the induction of delayed hypersensitivity in rats by repetitive morphine treatments.

Previous in vitro experiments suggest that lymphocyte function may be altered in the presence of opiates. The effect of morphine treatment upon specific T lymphocyte function in vivo was investigated in rats. Following morphine treatment, rats were incapable of responding to immunization with the T-dependent antigens of Mycobacterium bovis, strain BCG. The absence of a delayed hypersensitive skin response to tuberculin in chronic morphine-treated rats supports the hypothesis that opiates may interact with the cells of the immune system. A potential communication between the nervous system and cells of the immune system is proposed.

Animals↗