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Biomedical subjects

C C Smith

Publications and source records attributed to C C Smith.

At least 163 records · Page 9Linked to original sources
PubMed1985

Putative amino acid transmitters in lumbar cerebrospinal fluid of patients with histologically verified Alzheimer's dementia.

Concentrations of individual free amino acids were determined in lumbar cerebrospinal fluid (CSF) from patients with various complaints including histologically verified Alzheimer's dementia. Glycine and glutamine in the CSF of Alzheimer's dementia samples were lower than that of control samples. Only the concentration of glutamic acid in Alzheimer's dementia patients correlated with psychological measures. The reduction in glycine concentration was not specific for Alzheimer's dementia.

Adult↗
PubMed1985

Non-enzymatic glycosylation of plasma lipoproteins in vitro.

Human very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoproteins (HDL2 and HDL3) were glycosylated in vitro by incubation with high concentrations of glucose and glucose-6-phosphate. Glycosylated lipoproteins showed enhanced mobility on agarose electrophoresis when compared to control lipoproteins, samples treated with glucose-6-phosphate being more strongly affected. Extent of glycosylation of LDL was determined using thiobarbituric acid, LDL incubated with glucose exhibiting degrees of glycosylation 15-117% in excess of control. LDL incubated with glucose-6-phosphate however, gave values similar to those obtained with control incubations. Amino acid analysis of protein hydrolysates prepared from VLDL and LDL fractions incubated with glucose revealed reductions of up to 53% in the levels of free lysine when compared to control lipoprotein samples. The appearance of 2 novel peaks, probably corresponding to glucosyllysine, was also observed. The effects seen with glucose-6-phosphate however, were not as marked as expected. None of the other amino acids measured were decreased. These data show that plasma lipoproteins can be glycosylated in vitro and that an indication of the degree of glycosylation (by glucose) may be obtainable using thiobarbituric acid. Amino acid analysis revealed that the probable binding site for glucose on the apoproteins are the lysine residues. Although glucose-6-phosphate also binds to lysine residues the effects produced by this agent on plasma lipoproteins may also involve other mechanisms requiring further investigation.

Amino Acids↗
PubMed1984

Nuclear magnetic resonance (NMR) imaging in the diagnosis of spinal osteomyelitis.

Nuclear Magnetic Resonance Imaging (NMR) was performed on two patients whose clinical radiograph and bone scanning suggested spinal osteomyelitis before and after successful antimicrobial therapy. The images obtained suggest that NMR may be more useful in the diagnosis of this condition than other conventional imaging techniques. Hitherto NMR has not been considered particularly useful for the diagnosis of bone disease. This may be true for cortical bone, from which no signal is obtained using the NMR technique, but for medullary bone it appears to be a potentially useful, non-invasive and safe method of diagnosis.

Adult↗
PubMed1984

Alloplastic spermatocele: diffusion across the allograft material and survival of spermatozoa in vitro and in vivo.

Alloplastic spermatoceles have not proved to be a very successful method for acquiring fertile spermatozoa from patients with obstructive azoospermia. Many basic aspects of spermatocele function have apparently not yet been considered; therefore, we performed experiments to determine the motility survival of rat spermatozoa in spermatoceles in vivo and in vitro, and of human spermatozoa in spermatoceles in vitro. Also, net diffusion of Na+, K+, 3H-H2O, 3H-inulin and 3H-polyethyleneglycol from alloplastic spermatoceles was determined in vitro. Spermatoceles were constructed from expanded polytetrafluoroethylene. In general, neither rat nor human spermatozoa motility survived 24 hr. incubation in alloplastic spermatoceles in vitro or in vivo. Na+ and K+ diffused from alloplastic spermatoceles, demonstrating that specific intraluminal electrolyte concentrations cannot be maintained in polytetrafluorethylene spermatoceles. 3H-H2O diffused freely across the spermatocele wall, demonstrating that fluids can enter or exit the spermatocele lumen and potentially effect sperm survival. 3H-inulin (m.w. 5000) and 3H-polyethyleneglycol (m.w. 4000) were largely retained in the spermatocele lumen over the 3-day experimental period. It is recommended that other basic aspects of spermatocele design be worked out experimentally before perhaps premature designs are installed in human patients.

Animals↗
PubMed1984

Opportunistic pasteurella multocida meningitis.

Pasteurella multocida bacteraemia and meningitis followed elective surgery on the sinuses. The organism is thought to have been derived from close contact with dogs, and the infection responded to appropriate antimicrobial drugs, the patient making a complete recovery.

Ampicillin↗
PubMed1984

Prevention of rotavirus-induced diarrhea in neonatal mice born to dams immunized with empty capsids of simian rotavirus SA-11.

Female CF-1 mice were immunized subcutaneously with a rotavirus vaccine consisting of noninfectious, purified empty capsids from simian rotavirus SA-11 and were given a booster dose at 14-17 days of gestation. The vaccinated animals developed high titers of rotavirus-specific IgG in colostrum and milk. Virus-specific IgA titers were significantly (150-fold) lower, and virus-specific IgM was not detected. These results contrast with those obtained in natural and experimental infections of the gastrointestinal tract with epizootic-diarrhea infant-mouse ( EDIM ) virus; in such cases, intestinal and lacteal virus-specific antibody is primarily of the IgA isotype. Suckling mice born to vaccinated dams were challenged with infectious EDIM virus and monitored for the development of diarrheal disease; these neonates acquired maternal antibody and did not develop diarrhea.

Animals↗
PubMed1984

Metronidazole in the treatment of non-specific vaginitis (NSV).

In a large multicentre study of 429 patients with the usual signs and symptoms of non-specific vaginitis (NSV), we studied the effect of different doses of metronidazole. The patients were divided into five treatment groups as follows: group A was given 400 mg metronidazole three times daily for seven days, group B 2000 mg as a single dose, group C 2000 mg on days 1 and 2, group D 2000 mg on days 1 and 3, and group E was given 1200 mg metronidazole once daily for five days. At follow up examination four weeks from the start of treatment, patients in groups D and E showed the best clinical results with cure rates of 94.0% and 93.6% respectively. In addition the rate of reisolation of Gardnerella vaginalis was lowest in group D. We therefore recommend metronidazole 2000 mg on days 1 and 3 as routine treatment for non-specific or vaginitis associated with gardnerella.

Adolescent↗
PubMed1984

Renal excretion of chromium-51 chloride in the dog.

To examine the renal handling of the trace element chromium, clearance studies were performed in pentobarbital sodium-anesthetized mongrel dogs following either gavage or intravenous administration of chromium-51(III) chloride. Ultrafilterable plasma chromium-51 comprised as much as 9-19% of the total plasma chromium-51 when the isotope was given by gavage but only 2-3% when given by intravenous infusion. The mean ratio of the clearance of ultrafilterable plasma chromium-51 to that of endogenous creatinine was approximately unity in all dogs [0.97 +/- 0.11 to 1.14 +/- 0.10 by gavage (n = 5); 0.84 +/- 0.05 to 0.97 +/- 0.05 intravenously (n = 4)]. Regardless of the route of administration, ultrafilterable plasma chromium-51 concentration and glomerular filtration rate appeared to be the primary determinants of renal chromium-51 excretion.

Animals↗
PubMed1984

Can erythema nodosum and reactive arthritis be a sequel to Shigella flexneri gastroenteritis?

Erythema nodosum and seronegative arthritis associated with diarrhoea was previously regarded as implying the presence of inflammatory bowel disease. Recently, however, erythema nodosum has been described as a sequel to diarrhoea caused by infection with Salmonella typhimurium, Yersinia enterocolitica and Campylobacter jejuni. We report two patients in whom erythema nodosum and reactive arthritis followed acute Shigella flexneri gastroenteritis, a rare association.

Adult↗
PubMed1983

The evoked release of endogenous amino acids from tissue prisms of human neocortex.

The K+-evoked release of 13 amino acids has been determined from tissue prisms of neocortex from patients of various ages, and from rats. Prisms were prepared from various regions of human neocortex obtained at neurosurgery. Upon depolarization aspartate, glutamate and gamma-aminobutyrate (GABA) were shown to be preferentially released. The efflux of glutamate was calcium-dependent. Prisms prepared from human neocortex obtained shortly after death also exhibited preferential K+-induced release of putative amino acid transmitters. Absolute concentrations released into the media were similar to those found for neurosurgical samples. Comparison of the release data for rat and human samples revealed that the efflux of aspartate, glutamate and GABA occurred to a greater extent from rat brain preparations. The K+-evoked release of glutamate from human samples showed a significant linear increase from 12 to 68 years of age.

Aged↗
PubMed1983

Amino acid release from biopsy samples of temporal neocortex from patients with Alzheimer's disease.

Tissue prisms prepared from neurosurgical samples of temporal neocortex of Alzheimer and control patients, upon depolarization preferentially released aspartate, glutamate and gamma-aminobutyrate (GABA). The Alzheimer and control samples did not significantly differ in the pattern of amino acid release, although acetylcholine synthesis by the Alzheimer tissue prisms was greatly reduced. There was no correlation between the efflux of any amino and acetylcholine synthesis. These observations suggest that in Alzheimer's disease there are no major changes in the extracellular concentrations of these putative amino acid transmitters.

Acetylcholine↗
PubMed1983

An open study of ceftazidime in the treatment of serious bacterial infection.

Ceftazidime, a new parenteral cephalosporin, was given by intravenous bolus injection to 50 patients admitted to hospital with a variety of serious infections. These included septicaemia, bronchopulmonary, urinary, gastro-intestinal and soft tissue infections. The drug proved to be effective against a wide range of organisms, notably opportunistic Pseudomonas aeruginosa infections. In the 32 patients with positive cultures there was a cure rate of 85%. All Ps. aeruginosa infections were eradicated, but two relapsed post treatment in patients with recurrent urinary infections related to indwelling catheters. The drug was well tolerated and no serious side effects occurred. Two patients with salmonella septicaemia relapsed after an initial clinical response, and one of these died.

Adolescent↗
PubMed1983

Presynaptic cholinergic dysfunction in patients with dementia.

Indices of presynaptic cholinergic nerve endings were assayed in neocortical biopsy samples from patients with presenile dementia. For those patients in whom Alzheimer's disease was histologically confirmed, [14C]acetylcholine synthesis, choline acetyltransferase activity and choline uptake were all found to be markedly reduced (at least 40%) below mean control values. The changes occurred in samples from both the frontal and temporal lobes and for [14C]acetylcholine synthesis the decrease was similar under conditions of high and low neuronal activity (as assessed by incubations in 31 mM and 5 mM K+ respectively). Samples from other demented patients, in whom the histological features of Alzheimer's disease were not detected, produced values for all three biochemical parameters which were similar to controls. For the total group of patients with presenile dementia there were correlations between values for the three markers of presynaptic cholinergic nerve endings suggestive of a loss of functional activity at these sites in Alzheimer's disease.

Acetylcholine↗
PubMed1983

Biochemical evidence of selective nerve cell changes in the normal ageing human and rat brain.

Atrophy with ageing of human whole brain, entire temporal lobe, and caudate nucleus was assessed in autopsy specimens, by biochemical techniques. Only the caudate nucleus showed changes. Markers for several neurotransmitter systems were also examined for changes with age. In neocortex and temporal lobe of human brain, small decreases were detected in markers of cholinergic nerve terminals, whereas a large decrease (79%) occurred in the caudate nucleus. Findings were similar in striatum from 3--33-month-old rats. No change occurred in binding of [3H]quinuclidinyl benzilate by human samples. Markers of serotonergic terminals were also unchanged in human and rat brain. By contrast, binding of [3H]lysergic acid diethylamide and [3H]serotonin was decreased (32-81%) in human neocortex and temporal lobe, but not in caudate nucleus. A 43% loss of a marker of gamma-aminobutyrate terminals occurred in human neocortex, while [3H]muscimol binding increased (179%). No changes were detected in markers of catecholamine synapses in temporal lobe or rat striatum. Hence, with human ageing there appears to be a loss of markers of gamma-aminobutyrate neurones intrinsic to neocortex and acetylcholine cells intrinsic to the caudate nucleus, as well as a change in postsynaptic serotonin receptors in neocortex. These losses are accompanied by relative preservation of markers of ascending projections from basal forebrain and brain stem.

Aged↗
PubMed1983

Biochemical assessment of serotonergic and cholinergic dysfunction and cerebral atrophy in Alzheimer's disease.

Markers of serotonin synapses in entire temporal lobe and frontal and temporal neocortex were examined for changes in Alzheimer's disease by use of both neurosurgical and autopsy samples. Uptake of [3H]serotonin, binding of [3H]imipramine, and content of indolamines were all significantly reduced, indicating that serotonin nerve terminals are affected. Binding of [3H]serotonin was also reduced, whereas that of [3H]quinuclidinyl benzilate, [3H]muscimol, and [3H]dihydroalprenolol were unaltered. When the Alzheimer's samples were subdivided according to age, the reduction in [3H]serotonin binding was a feature of only autopsy samples from younger patients. In contrast, presynaptic cholinergic activity was reduced in all groups of Alzheimer's samples, including neurosurgical specimens. Five markers, thought to reflect cerebral atrophy, cytoplasm, nerve cell membrane, and neuronal perikarya were measured in the entire temporal lobe. In Alzheimer's disease the reductions (mean 25%, range 20-35%) were thought to be too large to be due only to loss of structures associated with the presumed cholinergic perikarya in the basal forebrain and monoamine neurones in the brain stem.

Acetylcholine↗
PubMed1983

Rotavirus-associated traveler's diarrhea: neutralizing antibody in asymptomatic infections.

The sera of patients with traveler's diarrhea were assayed for rotavirus-specific immunoglobulins in enzyme-linked immunosorbent and micro-neutralization assays. The antigenically related simian rotavirus SA-11 was used in both assays. Although similar titers of rotavirus-specific binding immunoglobulin G and A were observed in the sera of both symptomatic and asymptomatic subjects, clinical illness appeared to correlate with the failure to detect increased (greater than or equal to fourfold) titers of neutralizing antibodies in the post- as compared with the pretravel sera.

Antibodies, Viral↗