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Biomedical subjects

G Smith

Publications and source records attributed to G Smith.

At least 289 records · Page 16Linked to original sources

Suspected ehrlichial infection in five cats from a household.

Ehrlichiosis is a poorly recognized condition of cats that may be associated with anemia, leukopenia, thrombocytopenia, or dysproteinemia. Affected cats may have indirect fluorescent antibody titers to Ehrlichia canis and E risticii. We reviewed the clinical evaluation and response to treatment of 5 cats in a household where ehrlichial disease was suspected as the cause of recurrent leukopenias and thrombocytopenias. All of the cats had E risticii indirect fluorescent antibody titers and western blot confirmation of antibodies to 4 of the 9 major antigens of E risticii. Response to doxycycline was monitored serologically and hematologically in each cat, and indicated that administration of doxycycline at a dosage of 10 mg/kg of body weight, PO, every 12 hours, for a minimum of 21 days is necessary for treatment of this condition.

Animals↗

Ligation of the T cell co-stimulatory receptor CD28 activates the serine-threonine protein kinase protein kinase B.

The intracellular signaling pathways activated upon ligation of the co-stimulatory receptor CD28 remain relatively ill-defined, although CD28 ligation does result in the strong association with, and activation of, phosphatidylinositol (PI) 3-kinase. The downstream effector targets of the CD28-activated PI 3-kinase-dependent signaling pathway remain poorly defined, but recent evidence from other systems has shown that Akt/protein kinase B (PKB) is a major target of PI 3-kinase and have indicated that a major function of PKB is the regulation of cell survival events. Given the strong coupling of CD28 to PI 3-kinase and the known protective effects of both CD28 and PI 3-kinase against apoptosis in different cell models, we investigated the effects of CD28 on PKB activation. We demonstrate that ligation of CD28 by either anti-CD28 monoclonal antibodies or the natural ligand B7.1, results in the marked activation of PKB in both the leukemic T cell line Jurkat and freshly isolated human peripheral blood-derived normal T lymphocytes. Our data suggest therefore, that PKB may be an important intracellular signal involved in CD28 signal transduction and demonstrate CD28 coupling to downstream elements of a signaling cascade known to promote cell survival.

Androstadienes↗

Legal and societal issues facing survivors of childhood cancer.

The Boy Scouts have a good motto: Be prepared! Childhood cancer survivors and their families--and, if that is their preference, spouses and significant others--must learn to become their own best advocates. Life after cancer should be attacked with the same determination and perseverance that is allocated to life during cancer. Know your resources and how to use them. Learn networking skills and establish your own helping network. This article should give you a good start. Do not let yourself become a victim. Take charge of your future. Childhood cancer survivors are a hardy breed and should be a productive and successful force in society.

Child↗

Risk factors for bacterial gill disease in young rainbow trout (Oncorhynchus mykiss) in North America.

A retrospective whole-population survey was used to investigate putative risk factors for bacterial gill disease (BGD) in young hatchery-reared rainbow trout in North America. Three sets of analyses were done. The first analysis included as cases all of the hatcheries in which there was at least one outbreak of BGD during the 2-year study interval, regardless of location of the outbreak in the hatchery. The case group for the second analysis was limited to hatcheries for which the BGD outbreak occurred inside the hatch house. The case group for the third analysis was limited to hatcheries for which the BGD outbreak occurred outside of the hatch house. For the logistic regression that combined all cases of BGD (regardless of location of the outbreak), there was a significant association between mortality from bacterial gill disease and previous experience with BGD outbreaks (odds ratio (OR) = 10.1; 95% confidence interval (CI) = 5.6, 18.2), being a commercial trout hatchery (OR = 5.2; 95% CI = 2.6, 10.4), and being a hatchery with an annual salmonid fish production of > 250,000 fish (OR = 2.9; 95% CI = 1.5, 5.7). For BGD outbreaks that occurred in the hatch house, the presence of fish in the hatch house water supply significantly increased the odds of an outbreak (OR = 5.3; 95% CI = 2.2, 12.6), as did the use of ultraviolet radiation to disinfect the hatch house water (OR = 7.5; 95% CI = 2.2, 25.8), previous experience with bacterial gill disease (OR = 19.3; 95% CI = 7.9, 46.8), and being a commercial hatchery (OR = 7.7; 95% CI = 3.2, 18.6). The odds of a BGD outbreak outside of the hatch house was significantly associated with previous experience with BGD (OR = 4.3; 95% CI = 2.2, 8.6) and with being a hatchery with an annual salmonid fish production > 50,000 pounds (OR = 2.5; 95% CI = 1.2, 5.1).

Animals↗

The economics of parasite control: obstacles to creating reliable models.

Models of the population biology and transmission of helminth parasites of domestic ruminants do not generally include any explicit reference to production because that would require the identification of a systematic relationship between parasitism and production loss. This is difficult because (1) the relationship between parasitism and production loss (in so far as we can identify one) is non-linear, (2) it is by no means clear which index of parasitism we should use in defining the nature of the relationship and (3) time delays in the system and the multicausal nature of production losses make it difficult to tease out those components of the loss that are attributable to parasitism.

Animals↗

Microembolization during endovascular and conventional aneurysm repair.

PURPOSE: Endovascular aneurysm repair has been advocated as a "minimally invasive" alternative to conventional aneurysm surgery. However, because of manipulation within the aneurysm sac, endovascular techniques may result in massive microembolization. METHODS: In this study lower limb microemboli were quantified in 29 patients undergoing conventional (11 straight and 7 bifurcated grafts) and endovascular aneurysm repair (8 aortoiliac, 1 straight, and 2 bifurcated grafts) by insonation of the superficial femoral artery with a 2 MHz Doppler probe. Emboli were detected as high-intensity, short-duration signals on the background Doppler trace. Differentiation of gaseous emboli from particulate emboli was achieved by calculation of the sample volume length (emboli velocity x duration = sample volume length) for each embolus (N = 4927). Previous experiments had determined that a sample volume length < 1.4 cm represented particulate embolization. RESULTS: The number of gaseous, particulate, and total emboli were significantly greater in the endovascular group compared with the conventional group (p < 0.05). CONCLUSIONS: These data demonstrate that peripheral microembolization is significantly higher during endovascular aneurysm repair than during conventional surgery. Methods to reduce embolization must be developed before endovascular aortic surgery is widely adopted.

Aged↗

Effects of diacerhein in an accelerated canine model of osteoarthritis.

OBJECT: To determine whether diacerhein has a disease-modifying effect in an accelerated canine model of osteoarthritis. DESIGN: Fourteen adult mongrel dogs underwent unilateral L4-S1 dorsal root ganglionectomy (DRG), followed 3 weeks later by ipsilateral anterior cruciate ligament transection. Seven dogs received diacerhein (15-20 mg/kg) daily throughout the interval between DRG and sacrifice, eight weeks after ligament transection. The other seven dogs served as OA controls. RESULTS: The mean volume of synovial fluid obtained from the OA knee of the diacerhein-treated dogs was approximately 40% less than that from the OA knee of the controls. In addition, diacerhein appeared to reduce the severity of fibrillation (femoral condyle) and full-thickness ulceration (trochlear ridge) of the articular cartilage and the level of collagenase activity in extracts of the OA cartilage, and to increase net PG synthesis in the OA cartilage, although none of the above changes were statistically significant. CONCLUSION: The differences between the diacerhein group and untreated OA controls, even though not statistically significant, suggest that diacerhein was active in this rapidly progressive model of OA. Because changes associated with initiation of OA may be different than those associated with progression, whether diacerhein has a disease-modifying effect should be examined in a less rapidly progressive model.

Animals↗

Anger regulation deficits in combat-related posttraumatic stress disorder.

We describe a typology of regulatory deficits associated with anger in combat-related posttraumatic stress disorder (PTSD). Cognitive, arousal, and behavioral domain deficits in anger regulation were observed clinically in PTSD patients with high levels of anger who were participating in a multi-year trial of a structured anger treatment. We also describe a category of patients whose anger type we have termed "ball of rage." These patients exhibit regulatory deficits in all three domains of anger regulation. We offer a conceptual framework to advance the understanding of anger associated with PTSD and to guide its effective treatment.

Adaptation, Psychological↗

Incorporation of iododeoxyuridine in multicellular glioma spheroids: implications for DNA-targeted radiotherapy using Auger electron emitters.

A promising new treatment for glioma involves Auger electron emitters such as 125I or 123I conjugated to deoxyuridine (IUdR). However, the presence in tumour deposits of non-proliferating cells with clonogenic potential poses a major limitation to this cycle-specific therapy. We have used multicellular tumour spheroids derived from the human glioma cell line UVW to study [125I]IUdR-targeted radiotherapy in aggregates containing cells in different proliferative states. Autoradiographic identification of labelled cells indicated that nuclear incorporation of [125I]IUdR decreased markedly with increasing size of spheroid. IUdR incorporation was maximal in the surface layer of cells and decreased with depth within spheroids. Radiopharmaceutical uptake corresponded closely to the regions of cell cycling as indicated by staining for the nuclear antigen Ki67. The uptake of drug was enhanced by increasing the duration of incubation from 52 h to 104 h. These observations suggest that significant sparing of non-cycling malignant cells would result from treatment delivered as a single injection of radiolabelled IUdR. To achieve maximal therapeutic effect. IUdR should be administered by multiple injections, by slow release from biodegradable implants or by slow-pump delivery.

Antigens, Neoplasm↗

Plant-derived immunocontraceptive vaccines.

The use of transgenic or virus-infected plants to produce vitally needed vaccines for developing nations has been made possible by rapid advances in plant molecular biology and biotechnology during the last decade. Plant-based vaccines would be a welcome development for many impoverished countries that lack the capital-intensive infrastructure required to produce much-needed vaccines. The approach would also be ideally suited to the delivery of oral immunocontraceptive vaccines to a wide range of herbivore species. This review looks at the progress made to date in the use of plants for vaccine production, how this technology may be used in the future to deliver immunocontraceptive vaccines to free-ranging wildlife species, and the many problems that will have to be overcome if this promising approach is to ever 'bear fruit'.

Animals↗

Serum N-terminal pro-atrial natriuretic factor 1-98 before and during thyroxine replacement therapy in severe hypothyroidism.

Decreased plasma concentrations of atrial natriuretic factor (ANF) and of its N-terminal prohormones have been demonstrated in severely hypothyroid patients compared with control subjects, and shown to normalize with thyroxine (T4) replacement therapy. Whether this depends on thyroid hormone deficiency exclusively or is secondary to hemodynamic changes that result from it remains a matter of debate. In a recent investigation dose-related increases in both ANF and N-terminal prohormones of ANF by T4 replacement therapy in incremental doses increased at 4-week intervals were demonstrated. It was suggested that thyroid hormones may enhance synthesis rather than release of atrial peptide hormones. The aim of the present study was to confirm this assumption in hypothyroid patients with normal cardiac performance. Serum N-terminal amino acids 1-98 (ie, pro-ANF 1-98) of pro-ANF was determined in 11 severely hypothyroid patients without pericardial effusion and with normal cardiac left ventricular function. Mean pro-ANF 1-98 concentration before T4 replacement therapy remained unchanged after 10 days on T4 (p = .12). After 2 months of therapy, mean pro-ANF 1-98 was significantly increased compared with pretreatment values (p < .003). A significant correlation to the increase in free T4 (r = 0.48, p < .01) but not to the decrease in thyrotropin (TSH) (r = -0.32, p = .09) was found. The present results indicate that thyroid hormones directly increase pro-ANF 1-98 independently of cardiac hemodynamics in the hypothyroid state.

Adult↗

Intraperitoneal lignocaine for pain relief after total abdominal hysterectomy.

In this preliminary randomized study, we have measured pain scores at rest and on movement, 24 and 48 h after operation in 19 control patients, who received 50 ml of saline i.p., and in 20 test patients, in whom 50 ml of saline solution containing lignocaine 200 mg and adrenaline 1:500,000 were instilled into the peritoneal cavity after total abdominal hysterectomy. We found that there was no difference in linear analogue scores for nausea, pain on movement or morphine consumption after operation between the two groups, but pain scores at rest were significantly lower in the lignocaine group at 24 and 48 h compared with the saline group. In the lignocaine group, blood sampling over a 3-h period revealed a mean maximum serum concentration of 0.4 microgram ml-1 at 3 h and a highest concentration in any patient of 0.87 microgram ml-1.

Adult↗

The value and use of the Qualified Medicare Beneficiary Program: early evidence from Tennessee.

The Qualified Medicare Beneficiary (QMB) Program eliminated the out-of-pocket costs of obtaining health care services under the Medicare program for some low-income beneficiaries who were previously ineligible for Medicaid. The program is underused, and little is known about its effects. The article describes the QMB Program and compares program beneficiaries with others whose out-of-pocket payments are covered by Medicaid. Using Medicare claims data covering QMBs in Tennessee, we found that the program financed a relatively high rate of use of Medicare services and saved low-income Medicare beneficiaries hundreds of dollars per month in out-of-pocket costs. Social workers can promote the program and increase the use of its covered services appropriately, thereby by maximizing its potential benefits to low-income people.

Cost-Benefit Analysis↗

Proteosomes, emulsomes, and cholera toxin B improve nasal immunogenicity of human immunodeficiency virus gp160 in mice: induction of serum, intestinal, vaginal, and lung IgA and IgG.

Intranasal immunization of mice with human immunodeficiency virus (HIV) rgp160 complexed to proteosomes improved anti-gp160 serum IgA and IgG titers, increased the number of gp160 peptides recognized, and stimulated anti-gp160 intestinal IgA compared with immunization with uncomplexed rgp160 in saline. These enhanced responses were especially evident when either a bioadhesive nanoemulsion (emulsomes) or cholera toxin B subunit (CTB) was added to the proteosome-rgp160 vaccine. Furthermore, anti-gp160 IgG and IgA in vaginal secretions and fecal extracts were induced after intranasal immunization with proteosome-rgp160 delivered either in saline or with emulsomes. Formulation of uncomplexed rgp160 with emulsomes or CTB also enhanced serum and selected mucosal IgA responses. Induction of serum, vaginal, bronchial, intestinal, and fecal IgA and IgG by intranasal proteosome-rgp160 vaccines delivered in saline or with emulsomes or CTB is encouraging for mucosal vaccine development to help control the spread of HIV transmission and AIDS.

Administration, Intranasal↗