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Biomedical subjects

S Rogers

Publications and source records attributed to S Rogers.

At least 145 records · Page 8Linked to original sources
PubMed1994

Immunoglobulin G antibody responses to polyvalent pneumococcal vaccine in children in the highlands of Papua New Guinea.

The immunoglobulin G (IgG) antibody responses to a pneumococcal polysaccharide vaccine were examined for 480 children aged 3 months to 5 years and living in Tari, Southern Highlands Province, Papua New Guinea. Antipneumococcal IgG to the seven serotypes most frequently causing invasive disease (types 2, 5, 6B, 7F, 14, 19F, and 23F) was measured by an enzyme-linked immunosorbent assay in serum collected before vaccination and 1 and 6 months after vaccination. Prevaccination antibody levels fell rapidly after 3 months of age and remained low throughout the first 2 years of life. One month after vaccination, geometric mean titers of antipneumococcal IgG to serotypes 2, 7F, 23F, and 5 were at least twice those of antibodies in nonvaccinated children of the same age from the ages of 5, 6, 9, and 12 months onwards, respectively; postvaccination antibody responses to serotypes 6B, 14, and 19F rose gradually during the second year of life. Elevated antibody titers to serotypes 2 and 7F were maintained 6 months after vaccination. Thus, young Papua New Guinean children are capable of mounting a good immune response to some pneumococcal capsular polysaccharides from a young age, and the antibody responses to capsular polysaccharides are consistent with studies in developed countries. However, in Papua New Guinea, the serogroup distribution of invasive disease matches the immunogenic components of the pneumococcal polysaccharide vaccine more closely than in developed countries, a fact which helps to explain the results of controlled trials in Papua New Guinea, in which this vaccine prevented death and severe morbidity from pneumonia in young children.

Age Factors↗
PubMed1994

Immunohistochemical markers for arthritis in psoriasis.

OBJECTIVES: To examine the immunohistological features in the involved skin of patients with psoriatic arthritis (PA) (n = 15), compared with those in involved skin from patients with psoriasis but no arthritis (n = 5), and with a group with normal skin (n = 4), to identify markers for arthritis in psoriasis. METHODS: Skin was obtained from patients by 6 mm punch biopsy and normal skin was provided by the department of plastic surgery. Samples were stained with monoclonal antibodies against T cells (CD3, CD8, CD4, CD45Ro), B cells (CD20), macrophages (mac387), vascular endothelium (FVIII-related antigen) and a Langerhan's cell marker (p155). The number of cells/vessels staining with each monoclonal antibody was calculated and serial sections of skin were examined to estimate the presence of DR+ keratinocytes. RESULTS: There were significantly more CD45Ro T-cells and blood vessels in patients with psoriatic arthritis compared with both psoriasis alone, and with normal controls (p < 0.02). While B-cells were not seen in psoriasis without arthritis or in normal skin, a small but significant number were observed in PA (p < 0.02). Furthermore, while DR+ keratinocytes were present in both psoriatic arthritis and psoriasis skin, there were significantly more DR+ cells in the psoriatic arthritis epidermis compared with psoriasis alone (p < 0.02). CONCLUSIONS: This study suggests that increased numbers of CD45Ro T-cells, greater vascularity, the presence of B-cells, and increased numbers of DR+ epidermal cells are markers for arthritis in patients with psoriasis.

Adult↗
PubMed1994

Electrical potential measurements in human breast cancer and benign lesions.

Electrical potentials were measured on the breast and at other sites in 110 women with palpable breast masses. The tumor site was significantly electropositive compared with control sites only when the tumor was a cancer, as determined by a subsequent biopsy; the electrical potentials were not influenced by age or menstrual cycle. The results indicate that, on average, altered electrical potentials detected by a noninvasive measurement on the skin reflect the presence of transformed cells in patients with breast cancer. Previous in vitro studies of breast tissue and breast epithelial cells suggest that the observed effect was due to a change in interstitial K+ concentration that arose from alterations in the activity of K+ channels. Electrical potentials may be suitable for diagnosis of individual patients if refinements are made in the measurement technique.

Adolescent↗
PubMed1994

Development and testing of computer software for nursing assessment and care planning at a spinal cord injury center.

This paper describes a pilot project using a Macintosh personal computer and customized software to computerize nursing admission assessment and care planning data. The project setting is a 47-bed Spinal Cord Injury Center with two inpatient units and an outpatient department serving approximately 1,000 patients with spinal cord injury at a Department of Veterans Affairs Medical Center in northern California. The computer software development, implementation, and evaluation are described. This software (MacNursing) was found to be a low cost, customized approach to computerizing spinal cord injury admission assessment data and care planning which reduces repetitive writing and facilitates continuity of care. Personal computers and this software have provided the mechanism for establishing a spinal cord injury patient database.

Humans↗
PubMed1994

[Occurrence of free receptor for interleukin 2 in serum and quantitative determinations of CD25+ in patients infected with HIV].

Serum soluble interleukin 2 receptor (sIL-2R) concentration and the percentage of lymphocytes presenting this receptor (CD25+) were investigated in 28 asymptomatic HIV carriers or patients with lymphadenopathy only and in 15 AIDS patients. The levels of sIL-2R were found to be higher in AIDS patients (mean 1060 U/ml) than in persons during the initial stages of infection (mean 750 U/ml) or controls (mean 470 U/ml). No significant differences in the quantity of CD25+ lymphocytes between these groups were observed, with the means of 1.0; 1.3 and 1.1, respectively. However, a decrease in percentage of these cells were found in patients with advanced HIV infection. Since sIL-2R is regarded as a marker of immune system activation its detection could be helpful in the assessment of the immune status impairment in HIV infected patients.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Release of platelet-derived growth factor activity from pig venous arterial grafts.

Intimal smooth muscle cell proliferation and superimposed atheroma are the main causes of late failure of saphenous vein bypass grafts. It has been suggested that these reactions are caused by the production of growth factors from the cells of the vessel wall. To test this hypothesis, we cultured segments of pig venous arterial grafts, removed 1 and 4 weeks after implantation, in serum-free medium for 24 hours. Tissue viability as assessed by adenosine triphosphate concentration was maintained throughout the 24-hour culture period (239 +/- 21 nmol/gm wet weight [standard error of the mean], n = 26, 0 hours; 240 +/- 24 nmol/gm wet weight, n = 17, 24 hours). Cell proliferation occurred and autoradiography showed proliferating cells to be located in the neointimal and medial layers. These cells were identified as smooth muscle cells by means of a monoclonal antibody to alpha-actin. Graft-conditioned media were tested for mitogenic activity by means of a fibroblast proliferation assay. Media conditioned for 24 hours produced significant stimulation of cell growth (284% +/- 30%, n = 17) above that obtained in culture medium alone (100%). This mitogenic activity was inhibited by 61% +/- 9%, n = 8, with a polyclonal-neutralizing antibody to platelet-derived growth factor. Reverse-transcription polymerase chain reaction analysis and Northern blots demonstrated platelet-derived growth factor B messenger ribonucleic acid (mRNA) in vein grafts but not in ungrafted vein. Analysis of graft tissue sections by in situ hybridization demonstrated an abundance of platelet-derived growth factor B mRNA positive cells in the endothelial and neointimal layers, as well as in the endothelial cells of the adventitial vessels. These data constitute direct evidence for active growth factor production within the cells of the vein graft. They also suggest that endogenously produced platelet-derived growth factor may play a role in regulating smooth muscle cell proliferation in this model.

Animals↗
PubMed1994

Some sensory neurons express neuropeptide Y receptors: potential paracrine inhibition of primary afferent nociceptors following peripheral nerve injury.

Neuropeptide Y (NPY) has been suggested to exert antinociceptive actions by inhibiting the release of neurotransmitters from trigeminal and dorsal root ganglia (DRG) neurons, but the site of direct NPY action in vivo and the NPY receptor subtype mediating these effects are unknown. 125I-peptide YY (PYY) was used to localize and characterize NPY receptor binding sites in trigeminal ganglia, DRG, and spinal cord of the rat, rabbit, and monkey. In the rat, rabbit, and monkey, 5-20% of trigeminal ganglia and DRG neurons express NPY binding sites. Unilateral cuff-induced neuropathy or transection of the rat sciatic nerve did not significantly alter the density or number of DRG neurons expressing NPY receptors. A unimodal size distribution for L4 and L5 DRG neurons expressing NPY binding sites in the rat was determined, with a mean cross-sectional area of 947 microns 2. In the spinal cord the highest concentration of NPY receptors is found in laminae I, II, V, X, and Onuf's nucleus. Pharmacological experiments using selective Y1 and Y2 receptor antagonists suggest that Y2 is the prominent NPY receptor subtype expressed in trigeminal ganglia neurons, DRG neurons, and spinal cord. Previous studies have demonstrated that a population of large-diameter, presumably myelinated primary afferents express NPY after peripheral nerve injury. NPY released from these injured large-diameter DRG neurons may act in a paracrine fashion to block the transmission of nociceptive information from the small- and medium-diameter DRG neurons that constitutively express NPY receptors. NPY receptors are therefore uniquely positioned to inhibit primary afferent nociceptors directly, especially after peripheral nerve injury.

Animals↗
PubMed1993

Thromboxane receptor blockade with BM 13,177 following toxic airway damage by smoke inhalation in sheep.

Thromboxane may play an important role in the pathogenesis of smoked mediated injury. We studied this possibility in 13 chronically instrumented sheep, which had the left lung exposed to smoke. BM 13,177, a thromboxane receptor antagonist, was given intravenously to six animals prior to smoke inhalation and during the experimental period. Seven animals received the vehicle. All animals were studied for 24 h under ventilatory support, then killed prior to harvesting lung tissue. Airway peak and plateau pressures in the vehicle-treated animals were elevated by 27% and 25% from baseline at 24 h post smoke inhalation. Concomitantly, the left pulmonary vascular resistance index rose continuously throughout the study period (baseline = 822 +/- 58; 24 h = 1819 +/- 84 dyn.s.cm-5.m2).BM 13,177 treatment completely prevented the rise in airway pressure, while the left pulmonary vascular resistance index was significantly attenuated (baseline = 726 +/- 79; 24 h = 1470 +/- 158 dyn.s.cm-5.m2) resulting in a significantly higher percentage of cardiac output being delivered to the smoked lung, compared to vehicle-treated animals. Thromboxane receptor blockade did not prevent smoke induced pulmonary edema formation. There was likewise no effect of BM 13,177 on the systemic hemodynamic changes seen following smoke inhalation. There was a decrease in cardiac index and an increase in systemic vascular resistance index in both groups. We conclude that smoke induced changes in airway and pulmonary vascular resistances may be mediated by thromboxanes. However, thromboxanes appear to play no role in the development of pulmonary edema and elevation of systemic vascular resistance following smoke inhalation injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1993

Reduced synovial membrane macrophage numbers, ELAM-1 expression, and lining layer hyperplasia in psoriatic arthritis as compared with rheumatoid arthritis.

OBJECTIVE: To define the immunohistologic features of the synovial membrane (SM) of patients with psoriatic arthritis (PA) and to compare them with those of an age- and disease-duration-matched population of patients with rheumatoid arthritis (RA). METHODS: Synovial membrane needle biopsy was performed on 15 PA patients with knee involvement (8 had asymmetric oligoarthritis and 7 had symmetric polyarthritis) and on 15 RA controls. Specimens were stained with monoclonal antibodies against T cells (CD3, CD8, CD4, CD45RO), B cells (CD20), macrophages (Mac387, CD14), and cells bearing class II antigens (DAKO-DR). Vascular endothelium was examined using a polyclonal antibody to Factor VIII-related antigen, and adhesion molecule expression was examined using antibodies 1.3B6, 6.5B5, and 1.4C3, which identify endothelial leukocyte adhesion molecule 1 (ELAM-1), intercellular adhesion molecule 1 (ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1), respectively. RESULTS: There was significantly less lining layer hyperplasia, fewer macrophages, and a greater number of blood vessels in PA SM than in RA SM: ELAM-1 expression was less intense in PA than in RA SM, while there was no difference in expression of ICAM-1 and VCAM-1. Numbers of B cells, T cells, and T cell subsets (predominantly CD4, CD45RO T cells) were similar in both groups of patients. CONCLUSION: Our findings demonstrate important differences in the immunohistologic features of PA and RA SM: The PA SM is more vascular, ELAM-1 expression is less intense, and fewer macrophages invade the stroma and migrate to the lining layer than in RA SM: However, the lymphocytic infiltrate in the SM of both groups is similar.

Adult↗
PubMed1993

Trabecular bone does not have a fractal structure on light microscopic examination.

The fractal dimension of the boundary of trabecular bone in 62 biopsies was measured on histological sections using a box-counting method implemented on a microcomputer image analysis system. The calculated fractal dimension had a mean value of 0.99 with a normal distribution. Since this value is not greater than the topological dimension, trabecular bone, when examined by light microscopy, does not have a fractal structure. Conventional Euclidean dimensions will continue to be the most useful measurements in bone histomorphometry.

Adult↗
PubMed1993

Comparison of response to injury in organ culture of human saphenous vein and internal mammary artery.

Autologous saphenous vein grafts, unlike internal mammary artery grafts, suffer many late occlusions as a result of excessive proliferation of vascular smooth muscle cells and the superimposition of atheroma on the resulting thickened intima. We investigated the possible basis of this difference using organ cultures. Internal mammary artery segments and freshly isolated and surgically prepared saphenous vein segments were obtained from patients undergoing coronary artery bypass grafting. Internal mammary artery and freshly isolated vein segments showed a high degree of endothelial coverage and medial cell viability that were maintained during culture. Surgically prepared veins showed partial endothelial denudation and medial cell injury, both of which tended to be reversed during culture. Neointimal thickening was greater in surgically prepared vein (72 +/- 13 microns; n = 11) than in freshly isolated vein (44 +/- 8 microns; n = 10) or internal mammary artery (34 +/- 4 microns; n = 13) segments. The occurrence of proliferating cells in the medial layer was also significantly greater in surgically prepared vein (2.8 +/- 1.0/mm; n = 11) than in freshly isolated vein (0.8 +/- 0.3/mm; n = 9) or internal mammary artery (0.6 +/- 0.3/mm; n = 10) segments. The data show that although the smooth muscle proliferation was similar in undamaged saphenous vein and internal mammary artery, it was significantly greater in damaged vein. This implies that the greater intimal proliferation seen in saphenous vein grafts may arise not from intrinsic differences in arterial and venous smooth muscle cells but from a greater susceptibility to injury.

Cell Division↗
PubMed1993

Expression of cathepsin D and estrogen receptor in male breast carcinoma.

Male breast cancer is probably hormone dependent, but studies are few due to the rarity of this tumor. We have studied 21 cases of male breast cancer immunohistologically for estrogen receptor (ER) and cathepsin D (CD) expression. In carcinoma of the female breast ER expression is associated with longer patient survival and responsiveness to hormonal manipulation. Cathepsin D is an estrogen-regulated lysosomal protease with proteolytic and mitogenic properties whose presence denotes a functioning ER. In our series of male breast carcinomas 86% were ER positive and 62% were CD positive; this compares with typical figures of 50% and 66%, respectively, for female breast cancer. We observed no trends between expression of ER and CD and patient survival; immunostaining for ER and CD is unlikely to be clinically useful in carcinoma of the male breast. The high rate of ER positivity in males suggests that male and female breast carcinomas are biologically different tumors.

Aged↗
PubMed1993

Ventrolateral striatal dopamine depletions impair feeding and food handling in rats.

The present study was conducted to characterize the changes in feeding behavior produced by localized depletion of dopamine (DA) in the nucleus accumbens and subregions of the neostriatum in the rat. Food-deprived rats were given at least 2 weeks of training, which consisted of being placed in a Plexiglas box and being given 15-18 g of food for a 30-min session. After the training period, rats received bilateral injections of the neurotoxic agent 6-hydroxydopamine (6-OHDA) into the nucleus accumbens, ventromedial striatum, or ventrolateral striatum. Observations were made in 30-min tests on days 3 and 7 after surgery, and measures were obtained for total food intake, time spent feeding, rate of feeding, and forepaw usage during feeding. The ventrolateral striatum was the only site at which dopamine depletion altered aspects of food intake. Rats with ventrolateral striatal DA depletion had reductions in food intake, decreases in the rate of feeding, and impaired forepaw usage during feeding. Time spent feeding was not significantly affected by DA depletion. Water consumption was significantly reduced by DA depletions in the ventrolateral striatum but not by depletions at other sites. These results indicate that ventrolateral striatal DA depletions decrease food intake by impairment of motor functions necessary for the performance of feeding behavior.

Animals↗
PubMed1993

Uridine diphosphoglucose content of human erythrocytes: assessment by conversion to uridine diphosphoglucuronate.

To settle the ongoing controversy regarding differential uridine diphosphoglucose (UDPG) and uridine diphosphogalactose (UDPGal) content of erythrocytes, which may be important in evaluating the metabolic abnormality in patients with galactosemia, we derived a combined enzymatic-high-performance liquid chromatography (HPLC) assay. Uridine diphosphoglucuronate (UDPGA), the unique product of UDPG dehydrogenase activity, was separated and quantified by HPLC in extracts of human erythrocytes. The quantity of UDPGA produced in cell filtrates incubated with the enzyme corresponds to the amount of UDPG directly determined by HPLC. The amount of UDPGA produced was independent of the enzyme purity or activity used. On the other hand, the amounts of UDPG estimated by fluorometric measurement of the production of reduced nicotinamide adenine dinucleotide varied with the enzyme purity and activity. The combined enzymatic-HPLC method confirms the direct determinations of UDPG content of normal erythrocytes. The results indicate that, under appropriate conditions, the fluorometric-based assay will give accurate estimates of UDPG, but the direct HPLC method yields consistent and correct UDPG and UDPGal determinations.

Chromatography, High Pressure Liquid↗