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PubMed1996

Distinct immuno-localization of mucin and other biliary proteins in human cholesterol gallstones.

BACKGROUND/AIMS: Cholesterol gallstones consist of cholesterol crystals and smaller amounts of pigments and calcium salts, arrayed on a mucin plus protein matrix. The localization of the various biliary proteins in the stones has not been characterized. We aimed to localize several biliary proteins in gallstones in order to determine their possible role in stone formation and growth. METHODS: The distribution of several matrix proteins and their relationships to the minerals were determined using immunostaining and EDAX microanalysis on hemisected cholesterol gallstones. RESULTS: Pigment areas were rich in calcium and contained Cu, P and S. These elements were absent in cholesterol regions. Mucin was identified in a three-dimensional network intercalated between cholesterol crystals and as septa between deposits of pigments and cholesterol; APF/CBP and ApN coated only the pigment deposits. No specific topographical localization was found for albumin or IgA. CONCLUSIONS: This suggests a role for mucin, APF/ CBP and ApN in the formation of cholesterol gallstones. We propose that cholesterol crystals bind directly to mucin, whereas calcium salts and pigments deposit on APF/CBP and ApN bind to the mucin.

Bile↗
PubMedDate not supplied

Comparison of nerve growth factor's effects on development of septum, striatum, and nucleus basalis cholinergic neurons in vitro.

In the central nervous system, nerve growth factor (NGF) affects basal forebrain cholinergic neurons during early development and in the adult mammalian brain. These neurons are located in medial septum, diagonal band of Broca, and nucleus basalis of Meynert. While the effects of NGF on the development of septal cholinergic neurons are well documented, only little is known about the influence of NGF on development of cholinergic neurons in the nucleus basalis. In addition to the basal forebrain cholinergic neurons, there are cholinergic interneurons in the corpus striatum, which form an anatomically and functionally distinct population of cholinergic neurons. These striatal interneurons have been reported to respond to NGF during early development; however, it is not known whether the effects of NGF on their development are similar to those on septal cholinergic neurons. We prepared cultures of dissociated cells from fetal rat septum, striatum, and nucleus basalis and investigated the development of cholinergic neurons localized in these three different areas in the presence or absence of NGF. We now report that, first, cholinergic neurons of striatum and nucleus basalis develop a more extensive fiber network and contain more acetylcholinesterase (AChE) per neuron than do cholinergic neurons of septum. The amount of choline acetyltransferase (ChAT) per cholinergic neuron is approximately the same in all three culture types when grown in the absence of NGF. Second, NGF treatment increases and anti-NGF treatment decreases the number of AChE-positive neurons in cultures of low plating density, suggesting that NGF is able to promote survival of cholinergic neurons of all three areas studied. Third, NGF increases the total length of fibers and the number of branching points of cholinergic neurons in septal cultures but not in cultures of striatum and nucleus basalis. Fourth, NGF treatment increases AChE activity in septal but not in nucleus basalis or striatal cultures, suggesting that AChE activity reflects the extent of the fiber network of cholinergic neurons of all areas. Fifth, NGF treatment produces severalfold elevations in ChAT activity in septal cultures and more modest increases in cultures of nucleus basalis and striatum, suggesting that NGF is able to stimulate ChAT activity also in the absence of a stimulatory effect on survival and fiber growth. Our results demonstrate that, during early development, NGF is able to affect survival and differentiation of all three populations of forebrain cholinergic neurons.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholinesterase↗
PubMed1996

Characteristics and service use of seriously mentally ill persons living in rural areas.

OBJECTIVE: Data from a cross-sectional survey of 210 current or former inpatients at Mississippi State Hospital and 197 informants, usually patients' family members, were used to compare the demographic, clinical, and service use characteristics of patients living in rural areas with those of patients living in nonrural areas. METHODS: All subjects completed structured face-to-face interviews. Information on recent use of community mental health center (CMHC) services was obtained from CMHC records. Characteristics of rural patients (N = 107) and nonrural patients (N = 103) were compared using chi square and t tests. RESULTS: Rural patients were less likely to have completed high school and more likely to be living with family members. Although rural and nonrural subjects were clinically similar, rural subjects were less likely to have received certain community mental health services such as case management and day treatment and were more likely to have used physical health services and to have been involved with the criminal justice system. CONCLUSIONS: Differences between rural and nonrural patients in patterns of service use are most likely a reflection of less availability or accessibility of mental health services in rural areas, resulting in spillover into physical health and criminal justice sectors. Rural community mental health centers need to formally incorporate families, local medical providers, and law enforcement officials into their network of care.

Activities of Daily Living↗
PubMed1997

Immunocytochemical evidence that GLUT4 resides in a specialized translocation post-endosomal VAMP2-positive compartment in rat adipose cells in the absence of insulin.

Insulin stimulates glucose transport in rat adipose cells through the translocation of GLUT4 from a poorly defined intracellular compartment to the cell surface. We employed confocal microscopy to determine the in situ localization of GLUT4 relative to vesicle, Golgi, and endosomal proteins in these physiological insulin target cells. Three-dimensional analyses of GLUT4 immunostaining in basal cells revealed an intracellular punctate, patchy distribution both in the perinuclear region and scattered throughout the cytoplasm. VAMP2 closely associates with GLUT4 in many punctate vesicle-like structures. A small fraction of GLUT4 overlaps with TGN38-mannosidase II, gamma-adaptin, and mannose-6-phosphate receptors in the perinuclear region, presumably corresponding to late endosome and trans-Golgi network structures. GLUT4 does not co-localize with transferrin receptors, clathrin, and Igp-120. After insulin treatment, GLUT4 partially redistributes to the cell surface and decreases in the perinuclear area. However, GLUT4 remains co-localized with TGN38-mannosidase II and gamma-adaptin. Therefore, the basal compartment from which GLUT4 is translocated in response to insulin comprises specialized post-endosomal VAMP2-positive vesicles, distinct from the constitutively recycling endosomes. These results are consistent with a kinetic model in which GLUT4 is sequestered through two or more intracellular pools in series.

Adipocytes↗
PubMed1998

Attracting physicians to underserved communities: the role of health networks.

As health networks battle for additional market share and encourage additional Medicaid HMO subscribers to use their physicians and hospitals, more health executives are analyzing proposals of how to attract qualified doctors to practice in poor rural or inner-city communities. Supplying more physicians to those areas by increasing the number of medical schools, expanding the National Health Service Corps (NHSC) program, and allowing more international medical graduates (IMGs) to pursue residency training in the United States have been relatively unsuccessful strategies to improve America's geographic maldistribution of medical manpower. This article focuses on several approaches that health networks might use to increase market penetration and at the same time deliver enhanced health services to the underserved. Health networks may provide eminent leadership in the overall design and governance of soundly conceived Medicaid HMOs; strengthen existing or develop additional community health/primary care centers; interface more effectively with local schools to foster Medicaid HMOs for children of low-income families; and reimburse at "premium rates" primary care physicians who practice in underserved communities. The reluctance of physicians to practice in these areas and of middle-income and upper-income taxpayers, and therefore elected officials, to support increased spending or redirection of funds continue to be major barriers for health alliances to demonstrate willingness to invest additional resources in poor inner-city and rural environments.

Ambulatory Care↗
PubMed1997

Elastic fiber during development and aging.

Elastin molecules aggregate in the extracellular space where they are crosslinked by stable desmosine bridges. The resulting polymer is structurally organized as branched fibers and lamellae, which, in skin, are wider (a few microns) in the deep dermis and become progressively thinner (fraction of a micron) towards the papillary dermis. Several general and local factors seem to regulate elastin gene expression, deposition and degradation. In skin, the volume density of the elastin network increases from birth up to maturity, when it accounts for about 3-4% of the tissue. However, its amount and distribution depend on dermis areas, which are different among subjects and change with age. Several matrix molecules (glycosaminoglycans, decorin, biglycan, osteopontin) have been found to be associated with elastin into the normal fiber, and several others have been recognized within pathologic elastic fiber (osteonectin, vitronectin, alkaline phosphatase in PXE). With age, and in some pathologic conditions, skin elastin may undergo irreversible structural and compositional changes, which seem to progress from localized deposition of osmiophilic materials to the substitution of the great majority of the amorphous elastin with interwoven filaments negative for elastin specific antibodies.

Adult↗
PubMed1977

Prolactin-like immunoreactivity: localization in nerve terminals of rat hypothalamus.

Antibodies to rat prolactin were used in immunohistochemical studies of the hypothalamus and preoptic area of the rat. Evidence was obtained that a protein immunochemically related to prolactin was stored in networks of nerve terminals of many hypothalamic areas such as the arcuate nucleus, the dorsomedial hypothalamic nucleus, and periventricular regions of the hypothalamus and preoptic area. The neuronal storage of a prolactin-like protein in the hypothalamus was unaffected by hypophysectomy.

Animals↗
PubMed2001

Two-dimensional monitoring of spiking networks in acute brain slices.

To understand spatiotemporally coordinated activity in neural networks and interaction between different areas or layers in brain tissue, simultaneous multisite recording is a prerequisite. For in vitro studies pursuing these goals, substrate integrated, planar microelectrode arrays (MEAs) have been developed to monitor spikes and local field potentials. Here we report for the first time recordings of single-unit spike activity with MEAs in acute slice preparations of the rat cerebellum. We compare these recordings to results of conventional techniques, and discuss the recording conditions in view of the equivalent circuits commonly used. Simultaneous recordings with tungsten microelectrodes and MEAs verified that recording characteristics and signal-to-noise ratios of MEA electrodes were comparable to those of conventional extracellular electrodes. Spike shapes were identical on both electrodes. We found no detectable overlap between spike signals recorded at neighboring MEA electrodes (200 microm spacing). Neuronal spike activity was detected with MEA electrodes at distances of up to 100 microm from the site of spike generation. We conclude that extracellular recording of independent single-unit spike activity with MEAs is indeed suitable to monitor network activity in acute slices, making MEAs an exceptionally useful tool for the assessment of fast network dynamics in acute slices.

Action Potentials↗
PubMedDate not supplied

Differential expression of galactocerebroside, myelin basic protein, and 2',3'-cyclic nucleotide 3'-phosphohydrolase during development of oligodendrocytes in vitro.

This paper describes the differential expression and localization of myelin components within membrane sheets produced by oligodendrocytes in vitro. In double-labeling experiments using antibodies to the myelin antigens 2',3'-cyclic nucleotide 3'-phosphohydrolase (CNP) and galactocerebroside (GC), the two antigens were coexpressed in at least 95% of oligodendrocytes at all ages examined. A small population of relatively undifferentiated cells expressed one antigen before the other. Within the membrane sheets produced by the cultured cells, CNP and GC are distributed differently. CNP is highly concentrated in cell bodies, in a network of processes extending from the cell body into the sheets, and around the perimeter of the sheets. CNP staining cannot be detected in some areas within the body of the sheet. When present, it is of low intensity. Under our labeling conditions, GC staining is found throughout the membrane sheets, except in the network of veins which are CNP+. GC and myelin basic protein (MBP) staining are seen in similar membrane domains even though GC is a surface component while MBP resides on the cytoplasmic face. Both the timing and localization of CNP immunostaining show that CNP is as early a marker for oligodendrocytes as GC, and support the idea that CNP may play a structural role in the myelin membrane. Double-labeling studies with GC and CNP antibodies also show that the true shape of a cell and the extent of its development are not always revealed by a single antigen. The differential distribution of antigens within membrane sheets illustrates that they contain areas of structural specialization that may reflect the situation in intact myelin.

2',3'-Cyclic Nucleotide 3'-Phosphodiesterase↗
PubMed1998

Neurons containing gastrin-releasing peptide and vasoactive intestinal polypeptide are involved in the reception of the photic signal in the suprachiasmatic nucleus of the Syrian hamster: an immunocytochemical ultrastructural study.

In mammals, the suprachiasmatic nuclei are involved in the generation of biological rhythms and are synchronized by light input coming from the retina. The targets of retinal afferents and the involvement of neurons containing gastrin-releasing and vasoactive intestinal peptides in photic reception were investigated in the suprachiasmatic nuclei of the Syrian hamster by using light- and electron-microscopic immunocytochemistry. Cholera toxin was used to trace retinal fibers and Fos immunoreactivity to visualize cellular response to light stimulation. Ultrastructural observations were made in the intermediate third of the nuclei, the area of highest overlap for the immunoreactivities investigated. Gastrin-releasing peptide and vasoactive intestinal peptide cell bodies were localized in the ventral part of the nuclei; their dense immunoreactive fiber network often displayed synaptic contacts. Both neuropeptides were colocalized in elongated cells observed near the optic chiasm. Following a light pulse in the middle of the subjective night, Fos protein was expressed in most gastrin-releasing peptide perikarya and in some vasoactive intestinal peptide cells. Retinal terminals mostly occurred in the midline zone between the suprachiasmatic nuclei. Symmetrical or asymmetrical retinal synapses were observed on gastrin-releasing peptide-immunoreactive dendrites and somata, but never on vasoactive intestinal peptide neurons. These results are discussed in relation to the photic entrainment of the circadian clock.

Animals↗
PubMed1987

The impact of small dams on parasitic diseases in Cameroon.

Economic development in Africa implies the provision of vast, sparsely populated regions with improved road networks and agricultural techniques. Climatic constraints mean that control of water resources is essential in arid areas. But hydrogrophic modifications also have the potential for adverse impact on the health of local populations. The extension of water sources and their all year round supply of water mean that people are attracted towards them, and to the same places where conditions favour the spread of intermediate hosts and vectors of parasitic diseases such as schistosomiasis, onchocerciasis, drocunculiasis and malaria. Doctor, epidemiologists, and the engineers involved in rural earth-works must therefore work together to establish systems that impede the transmission of such diseases. Examples from the Cameroon typify the need for such an approach.

Journal Article↗
PubMed2002

Sensorimotor cortical activity in patients with complete spinal cord injury: a functional magnetic resonance imaging study.

Residual activation of the cortex was investigated in nine patients with complete spinal cord injury between T6 and L1 by functional magnetic resonance imaging (fMRI). Brain activations were recorded under four conditions: (1) a patient attempting to move his toes with flexion-extension, (2) a patient imagining the same movement, (3) passive proprio-somesthesic stimulation of the big toes without visual control, and (4) passive proprio-somesthesic stimulation of the big toes with visual control by the patient. Passive proprio-somesthesic stimulation of the toes generated activation posterior to the central sulcus in the three patients who also showed a somesthesic evoked potential response to somesthesic stimulation. When performed under visual control, activations were observed in two more patients. In all patients, activations were found in the cortical areas involved in motor control (i.e., primary sensorimotor cortex, premotor regions and supplementary motor area [SMA]) during attempts to move or mental imagery of these tasks. It is concluded that even several years after injury with some local cortical reorganization, activation of lower limb cortical networks can be generated either by the attempt to move, the mental evocation of the action, or the visual feedback of a passive proprio-somesthesic stimulation.

Adult↗
PubMed2005

Surgical management of colorectal cancer in south-western Sydney 1997-2001: a prospective series of 1293 unselected cases from six public hospitals.

BACKGROUND: The aim of the present study is to provide local data for the management of colorectal cancers in the south-western Sydney health area from 1997 to 2001. METHODS: The data were collected prospectively. Follow up was conducted in late 2001 and early 2002. Data were cross-validated with hospital and area databases and with data from the New South Wales Registry of Births, Deaths and Marriages. RESULTS: This was an unselected series of 1293 patients from 36 surgeons; 16.5% of patients presented as emergencies. Only 3% presented as a result of bowel cancer screening. Of the 1293 patients, 1270 received an operation. There were 598 elective colonic resections with the mortality rate of 1.2%, reoperation rate of 2.7% and anastomotic leak rate of 0.8%. For the 410 elective rectal resections, the rates were 2.9%, 2.7% and 1.2%, respectively. For the 290 emergency operations, the rates were much worse at 7.7%, 6.6% and 4.8%, respectively. The corrected overall 3-year survival rate was 64%. For Dukes' A, B, C and D, the figures were 94%, 87%, 61% and 7%, respectively. CONCLUSIONS: Colorectal cancer is a major cause of mortality and morbidity in our community. Very few bowel cancers were discovered at the asymptomatic stage. This paper strongly supports community bowel cancer screening and early diagnosis. The local database has provided a rich source of information to benchmark management and outcomes of bowel cancer patients treated in the South Western Sydney Area Health Service. An area-wide computer network with online data input facilities at individual workplaces will improve data integrity and data collection efficiency.

Adult↗
PubMedDate not supplied

The distribution of astrocytes, oligodendroglia and myelin in normal and transplanted rat superior colliculus: an immunohistochemical study.

Immunohistochemical methods have been used to determine the distribution of macroglia and myelin in the normal rat superior colliculus (SC) and in grafts of fetal tectal tissue. The fetal tissue was derived from 15 day-old (E15) rat embryos and was transplanted onto the midbrain of newborn host rats of the same (PVG/c) strain. Antibodies to glial fibrillary acidic protein (GFAP) and carbonic anhydrase II (CAII) were used to visualize astrocytes and oligodendroglia respectively. Myelin was immunostained with antibodies to either proteolipid protein (PLP) or myelin basic protein (MBP). In the normal SC, GFAP positive astrocytes were found scattered throughout the SC, particularly in the superficial layers. They were especially prominent at the pial surface, around major blood vessels and at the midline between the two colliculi. CAII immunoreactive oligodendroglia and associated myelin were also found throughout the SC; by far the lowest density was seen in the stratum griseum superficiale (SGS). Both types of macroglia cell were found in abundance in tectal transplants, indicating that the precursors of these glial types were present in the E15 rat mesencephalon. In mature grafts, large numbers of fibrous astrocytes were found throughout the neuropil and the level of GFAP immunoreactivity was consistently greater than in host SC. Astrocytes seemed to be maintained in a reactive, perhaps immature state within the grafted tissue. Tectal transplants possessed large numbers of fully differentiated CAII-positive oligodendroglia and the grafts contained a dense network of myelinated axons. However the distribution of CAII and PLP immunoreactivity was not homogeneous; there were localized, well-defined regions that contained few oligodendroglia and relatively little myelin. These areas stained intensely for acetylcholinesterase (AChE) and were almost certainly homologous to the SGS of normal SC. The relative lack of oligodendroglia in the AChE stained patches in grafts and in SGS in situ suggests that local factors influencing the proliferation and distribution of oligodendroglia in normal SC may have been operating in a similar manner within the tectal transplant neuropil.

Acetylcholinesterase↗
PubMed2003

[Vertigo and dizziness associated with cerebral hemispheric lesions].

To investigate the clinical significance of vertigo and dizziness in diagnosing cerebral cortical lesion, we analyzed 12 patients with supratentorial lesions whose chief complaint was rotational vertigo or non-rotational dizziness. There were 8 patients with right, and 4 with left hemispheric lesions. The lesion was localized in the vicinity of the central sulcus in 3 patients, temporal and/or parietal regions in 6, and occipital region in 3. Vertigo was seen in three patients, two of them with lesions in the vicinity of the central sulcus, and one in the temporo-parietal junction. The other 9 patients complained dizziness. Supratentorial lesions accompanied by dizziness or vertigo were mostly localized in temporal or central areas that were probably analogous to the vestibular cortex proposed by animal studies. Dizziness caused by occipital lesion might be due to imbalance of the neuronal network between the vestibular cortex and occipital lobe.

Adult↗
PubMed2006

Prescription pattern at primary health care centres in Lagos State.

Health care received in health facilities depends on adequate consultation, correct prescription and dispensing with relevant information given to the patient. These are some of the indicators for rational drug use. The objective of the study was to determine the pattern of prescription among prescribers in twenty Primary Health Care Centers of Lagos State using some of these indicators used in investigating health facilities by the World Health Organisation and International Network for Rational Use of Drugs. The study was carried out using multi-stage random sampling in selecting the Primary Health Care Centers from each of the twenty Local Government Areas of Lagos State. Both prospective and retrospective data were collected and analysed using Epi-Info version 6. The results showed that there was polypharmacy, misuse of antibiotics and injections. There was no statistically significant difference between the retrospective and prospective indicators of mean drugs prescribed per encounter, percentage antibiotics prescribed and percentage of generic prescription. It was concluded that there was irrational prescription pattern in all the selected health facilities as evidenced by poly-pharmacy, misuse of antibiotics and low generic prescriptions. There is need for educational intervention to improve the prescribing habits of health professionals in these health facilities.

Anti-Bacterial Agents↗
PubMed1998

The Western New York Health Resources Project: developing access to local health information.

The Western New York Health Resources Project was created to fill a gap in online access to local health information resources describing the health of a defined geographic area. The project sought to identify and describe information scattered among many institutions, agencies, and individuals, and to create a database that would be widely accessible. The project proceeded in three phases with initial phases supported by grant funding. This paper describes the database development and selection of content, and concludes that a national online network of local health data representing the various geographic regions of the United States would contribute to the quality of health care in general.

Database Management Systems↗
PubMed1999

Registered designation of origin areas of fermented food products defined by microbial phenotypes and artificial neural networks.

Cheese produced from raw ewes' milk and chouriço, a Portuguese dry fermented sausage, are still produced in a traditional way in certain regions of Portugal by relying on colonization by microbial populations associated with the raw materials, equipment, and local environments. For the purpose of describing the product origins and types of these fermented foods, metabolic phenotypes can be used as descriptors of the product as well as to determine the presence of compounds with organoleptic value. The application of artificial neural networks to the metabolic profiles of bacterial isolates was assayed and allowed the separation of products from different regions. This method could then be used for the Registered Designation of Origin certification process of food products. Therefore, besides test panel results for these traditionally produced food products, another tool for validating products for the marketplace is available to the producers. The method can be improved for the detection of counterfeit products.

Animals↗