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Biomedical subjects

B L Black

Publications and source records attributed to B L Black.

At least 19 recordsLinked to original sources

Isolation of Nocardia asteroides from respiratory specimens by using selective buffered charcoal-yeast extract agar.

Nocardiosis is difficult to diagnose clinically and by laboratory methods. A patient presented with disease compatible with pulmonary malignancy, but Nocardia asteroides was isolated on buffered charcoal-yeast extract agar. Investigation revealed that this medium may be a suitable selective primary isolation medium for Nocardia species from respiratory specimens.

Animals

Vesicular stomatitis virus matrix protein inhibits host cell-directed transcription of target genes in vivo.

Infection by vesicular stomatitis virus (VSV) results in a rapid inhibition of host cell transcription and translation. To determine whether the viral matrix (M) protein was involved in this inhibition of host cell gene expression, an M protein expression vector was cotransfected with a target gene vector, encoding the target gene, encoding chloramphenicol acetyltransferase (CAT). Expression of M protein caused a decrease in CAT activity in a gene dosage-dependent manner, and inhibition was apparent by 12 h posttransfection. The inhibitory effect of M protein was quite potent. The level of M protein required for a 10-fold inhibition of CAT activity was less than 1% of the level of M protein produced during the sixth hour of VSV infection. Northern (RNA) analysis of cotransfected cells showed that expression of M protein caused a reduction in the steady-state level of the vector-encoded mRNAs. Expression of both CAT and M mRNAs was reduced in cells cotransfected with a plasmid encoding M protein, indicating that expression of small amounts of M protein from plasmid DNA inhibits further expression of both M and CAT mRNAs. Nuclear runoff transcription analysis demonstrated that expression of M protein inhibited transcription of the target genes. This is the first report of a viral gene product which is capable of inhibiting transcription in vivo in the absence of any other viral component.

Animals

Development of Ca2+ homeostasis in epithelial cells from embryonic and neonatal intestine.

The fluorescent probe fura-2 was used to assay Ca2+ levels in epithelial cell suspensions from embryonic and neonatal chick duodenum. Cell preparations maintained high viability, completely hydrolyzed fura-2/AM to fura-2, retained 92% of cellular fura-2 within the cytoplasmic compartment, and gave low autofluorescence values during assay. Fura-2 leakage from loaded cells occurred at all ages, but could be corrected for in subsequent calculations of cellular Ca2+. Cytoplasmic Ca2+ concentration was 76-80 nM in cells from 14- to 16-day embryonic intestine, rose significantly to 92-98 nM at 17-20 days, and reached 209 nM at 1-day post-hatch when assayed in buffers containing 1.3 mM Ca2+. The developmental rise in cytoplasmic Ca2+ was accompanied by an enhanced ability of cells to maintain a constant Ca2+ concentration at increased levels of extracellular Ca2+ and by a highly correlated rise in alkaline phosphatase (ALP) activity. Epithelial Ca2+ subsequently decreased to the "adult" value of 133-142 nM and was constant along the crypt-villus axis of neonatal intestine. These results verify that fura-2 can be used to compare baseline cytoplasmic Ca2+ values of epithelial cells from developing intestine, reveal that significant changes in Ca2+ homeostasis occur during ontogeny, and suggest that epithelial Ca2+ may modulate ALP activity during the differentiation of embryonic enterocytes.

Alkaline Phosphatase

Patient perceptions.

The cancer patient's perceptions about treatment, prognosis, and long-term care have emerged in the context of interaction with the changing healthcare system. A brief overview of cancer patients' perceptions regarding their disease and subsequent care is provided. The economic, organizational, and technological environment in which this care is provided and the patient's perceptions of that environment are discussed. In addition to economic pressures, the ever-increasing number of cancer patients, prolonged survival, and patients' perceptions have created changes in the healthcare system. These changes are mediated by important socioeconomic, cultural, and demographic characteristics of the cancer patient. Recommendations to address these changes are discussed.

Attitude to Health

Needs and recommendations for behavior research in the prevention and early detection of cancer.

Because life-style patterns affect many cancer risks, research on health-risk behavior and behavior change is critical to cancer prevention. This report recommends priorities for the next decade of psychosocial research on cancer prevention and detection. The leading priority for future research is to fill gaps in basic knowledge left by the rush to intervention and outcome studies. Such research must be theoretically driven and should aim to develop broad principles applicable to diverse health behaviors. Studies that include relevant process data on various stages of behavior change are considered more desirable than simple outcome studies. Epidemiologic investigations should be expanded to include measures of relevant behaviors, so that their impact on clinical outcomes might be established. More research is needed on lay perception of health risks and on individual and health-system barriers to effective cancer prevention and detection. Studies that address the needs of minority and underprivileged populations are crucial. Funding agencies' narrow categorical mandates impede interdisciplinary research on multiple risk factors and their interactions; these boundaries must be relaxed to promote such approaches. Funding agencies should also consider basic research as a long-term investment towards the development of effective interventions.

Health Behavior

Medicare and Medicaid fraud and abuse regulations.

Specific business arrangements that are protected under legislation and regulations governing parties doing business with Medicare or Medicaid are discussed. Regulations implementing the Medicare and Medicaid Patient Protection Act of 1987 specify practices and activities that are not subject to criminal penalties under the antikickback provisions of the Social Security Act or to exclusion from Medicare or state health-care programs. As of July 29, 1991, all organized health-care settings that receive payments from either Medicare or state health-care programs must comply with these regulations. The final rule sets forth "safe harbors"--exceptions to prohibitions against (1) kickbacks, bribes, rebates, and other illegal activities involving remunerations for patient referrals and (2) inducements to purchase or lease goods paid for by Medicare or state health-care programs. The safe harbors comprise 11 broad categories--investment interests, space rental, equipment rental, personal services and management contracts, purchase of a medical practice, referral services, warranties, discounts, employees, group purchasing organizations, and waiver of deductibles and coinsurance. Implications for pharmacy are discussed. These regulations will affect the purchase of pharmaceuticals by institutional pharmacies. Each institution should review its current practices to determine whether they are within the safe harbors.

Fraud

Extracellular lipid deposition in atherosclerosis.

Atherosclerotic lipid deposits found in the core region of fibrous plaques are almost entirely extracellular, but it is not known whether they are derived from necrosis of cells containing accumulated lipid or from direct extracellular lipid accumulation. New evidence pertaining to this question has been obtained through the use of recently developed techniques for preserving and staining lipids in electron microscopy, and through a detailed morphologic and chemical examination of human aortic fibrolipid lesions, which are progenitor lesions for fibrous plaques. The evidence favours a substantial role, perhaps a dominant role, for extracellular lipid accumulation in the formation of the fibrous plaque core region.

Aorta

Focal toxicity of oxysterols in vascular smooth muscle cell culture. A model of the atherosclerotic core region.

Cell necrosis and reactive cellular processes in and near the atherosclerotic core region might result from short-range interactions with toxic lipids. To model these interactions in cell culture, focal crystalline deposits of cholestane-3 beta,5 alpha,6 beta-triol, 25-OH cholesterol, and cholesterol were overlaid by a collagen gel, on which canine aortic smooth muscle cells were seeded. Oxysterols, but not cholesterol, caused focally decreased plating efficiency and cell death, leading to the formation of a persistent circular gap in the cell culture. Cholestanetriol was largely removed from the culture dishes over 3 to 4 weeks, whereas cholesterol and 25-OH cholesterol were largely retained. Smooth muscle cells were motile even in proximity to oxysterol crystals, with occasional suicidal migration toward the crystals. Chemoattraction, however, could not be demonstrated. Despite toxicity, cholestanetriol did not appear to alter the fraction of cells exhibiting 3H-thymidine uptake, even in areas close to the crystals. Thus, oxysterols may be toxic to some cells, without causing major impairment of the migration and proliferation of nearby cells. This would allow the simultaneous occurrence of cell death and proliferation evident in atherosclerosis.

Animals

Preparation of microvillus membrane vesicles from the intestine of embryonic and young chicks.

1. A procedure is described for the isolation of microvillus membranes from 19-day old embryonic, newly hatched, and 2-day old chicken intestine. 2. The magnesium concentration of epithelial cell homogenates is shown to be a crucial factor in obtaining membranes of equal purity from the three age groups. 3. Microvillus membranes are purified 20-25 fold over the original homogenate and form vesicles which are tightly sealed based on the Na+-dependent accumulation of glucose to levels four to five times equilibrium values. 4. These membrane preparations should prove useful in future studies concerning the embryonic and neonatal development of microvillus enzymes and nutrient transport systems in the chicken.

Animals

Regulation of goblet cell differentiation by calcium in embryonic chick intestine.

The potential role of calcium as a regulator of goblet cell differentiation was tested by culturing duodenal explants from 14-day chicken embryos in media containing a range of calcium concentrations. Extracellular calcium in vitro approximated the range of plasma calcium concentration that was found to rise by 16% during the third week of embryonic development. As ionic calcium was increased from 0.9 to 2.0 mM in 48-h cultures, the number of goblet cells per 100 ridges increased progressively from 29 +/- 2.2 to 158 +/- 6.9 while attaining a distribution on the previllous ridges similar to that in ovo. The rate of goblet cell differentiation in vitro exceeded that in ovo when extracellular calcium was increased to 1.1 mM and was maximal at 1.6-2.0 mM calcium. Neither the growth of previllous ridges nor gross morphology of the tissue was altered as extracellular calcium was increased. Goblet cell differentiation in 1.3 mM calcium was stimulated by 0.1 microM calcium ionophore and inhibited by the calmodulin antagonist trifluoperazine, indicating an intracellular site for calcium action. These results indicate that calcium plays a primary role in regulating goblet cell differentiation in embryonic intestine and suggest that rising levels of plasma calcium influence the rate of differentiation in ovo.

Animals

Development of glucose active transport in embryonic chick intestine. Influence of thyroxine and hydrocortisone.

1. Glucose active transport is detectable in 12-day-old embryonic chick duodenum and increases at least 11-fold after 4 days of postnatal life. 2. Glucose active transport develops at the in vivo rate in 72-hr cultures of 14-day embryonic duodenum. 3. In the presence of either 1 nM thyroxine or 1 microM hydrocortisone in vitro, glucose active transport reaches levels approximately 200% of control values (equivalent to 18-19 day levels in vivo). 4. Thyroxine and hydrocortisone act by different mechanisms based on their antagonistic interaction and differences in time course of action, requirement for protein synthesis and modulation by extracellular calcium.

Animals

Influence of hormones on glycogen and glucose metabolism in embryonic chick intestine.

Previous studies on the development of embryonic intestine in vitro have revealed a stimulation of epithelial differentiation by the hormones hydrocortisone (HC) and thyroxine (T4). To determine whether these hormones also influence epithelial metabolism, duodena from 14-day-old chicken embryos were cultured for 72 h in the absence of hormones (controls) or in the presence of 1 nM T4 or 1 microM HC. In control cultures, glycogen accumulated within the duodenal epithelium to the level found at 17 days in vivo. T4 reduced glycogen accumulation to 34% of control values, whereas HC increased epithelial glycogen content by 45%. These hormonal effects were due, in part, to modulation of glycogen degradation. In T4 cultures, glucose oxidation activities within the epithelial layer and submucosal tissue were 300 and 140% of control values, respectively, and glucose utilization (removal from the culture medium) was increased. HC significantly decreased both glucose oxidation activity within the submucosal tissue and glucose utilization. These results are consistent with the hypothesis that HC regulates the early phase of epithelial differentiation that is characterized by low metabolic rate and accumulation of energy stores, whereas T4 elicits the prehatching phase of differentiation that is correlated with an increase in metabolic rate and utilization of stored products.

Alkaline Phosphatase

Home health care.

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Home Care Services

Hospital diversification: how to involve the pharmacy.

Participation by hospital pharmacy departments in planning and development of diversified services is described. Diversification requires market planning. Seven basic marketing steps are identification of mission, goals, and objectives; identification of growth strategies (market penetration, market development, product development, and diversification); market analysis of external factors (size, growth, and logistics; reimbursement and financial considerations; competition; regulatory issues; and legal issues); market analysis of internal factors (departmental organization and reporting lines, demographics of the institution, and costs and productivity associated with the new service); program development and design; implementation; and evaluation. Hospitals can diversify by expanding acute-care services through management contracts and mergers; developing new services to include long-term-care, ambulatory-care, occupational-health, and wellness programs; starting other health-care ventures, such as consulting, continuing medical education, and continuing education for nurses; and expanding into non-health-care businesses. Vertical diversification is finding new markets for existing services; horizontal diversification is development of new services for new markets. To diversify, an institution may need to change its corporate structure; it may form a family of corporations that includes a university, nonprofit hospitals, holding companies, for-profit corporations, joint ventures, and service organizations. Through diversification, institutions and pharmacy departments can create alternative sources of funding and offer more comprehensive services to patients.

Hospital Administration