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Biomedical subjects

A Gray

Publications and source records attributed to A Gray.

At least 307 records · Page 17Linked to original sources
PubMedDate not supplied

An exercise on the feasibility of carrying out secondary economic analyses.

Purchasers of health services need up to date information on cost-effectiveness of interventions to help in prioritising spending. But economists have not yet developed a formal methodology for reviewing and summing up evidence from individual economic evaluations which may have been conducted at different times and in different places, or indeed for assessing whether such systematic reviews are possible in this context. This paper discusses the problems of reviewing available economic information, using a body of literature on the economics of influenza vaccination to illustrate some relevant issues. First, the paper examines alternative methods for adjusting prices to take into account differences in currency and time periods: Retail Price Indices are compared with health specific inflation indices, and exchange rates are compared with Purchasing Power Parity (PPP) data. For the studies reviewed, the choice of conversion method made little practical difference. Secondly, the paper explores the possibility of summarising the results of a review in terms of quantities of resources used, rather than prices. This method is constrained by the available data, but could be more generally useful as it allows direct comparison of underlying technologies, and calculation of costs by attaching local unit costs to the resources associated with an intervention. These two exercises highlight many of the problems that arise in generalising from economic studies. Both methods need to be developed further if they are to be useful to decision makers.

Cost-Benefit Analysis↗
PubMedDate not supplied

Reproductive issues in HIV-seropositive women: a survey regarding counseling, contraception, safer sex, and pregnancy choices.

Sixty-nine HIV-seropositive women were surveyed with regard to the reproductive counseling they had received, contraception, safer sex practices, pregnancy histories, and pregnancy plans. Of the women surveyed, 84% and 90%, respectively, felt that they had access to the birth control and safer sex methods of their choice. Less than half felt that their physician had adequately counseled them about birth control. Women primarily cited social workers (46.4%) or nurses (34.8%) as the counseling source for birth control and safer sex. When informed about the reduced risk of vertical transmission with zidovudine (AZT), 33 women indicated that information regarding AZT would affect their future pregnancy decisions. Health care professionals need to be aware of this and counsel patients accordingly.

Adolescent↗
PubMedDate not supplied

Hydroxyethylation of hemoglobin by 1-(2-chloroethyl)-1-nitrosoureas.

Following treatment of cancer patients with three 1-(2-chloroethyl)-1-nitrosoureas, hemoglobin was isolated and analyzed by GC-MS for N-(2-hydroxyethyl)-N-terminal valine. This alkylated amino acid was liberated as a (pentafluorophenyl)thiohydantoin from the hemoglobin by a modified Edman degradation procedure. Following intravenous infusion of fotemustine [diethyl[1-[3-(2-chloroethyl)-3-nitrosoureido]ethylphosphonate] (ca. 90 mg/m2) the levels of (hydroxyethyl)valine in two patients increased steadily, reaching a peak of ca. 300 pmol/g after 6 h. In a further five patients receiving fotemustine (100 mg/m2) alkylation levels 24 h after treatment ranged from 132 to 1524 pmol/g of globin. Treatment with TCNU [1-(2-chloroethyl)-3-[2-[(dimethylamino)sulfonyl]ethyl]-1- nitrosourea] or ACNU [1-[(4-amino-2-methylpyrimidin-5-yl)methyl]-3-(2-chloroethyl)-3- nitrosourea] resulted in similar increases in (hydroxyethyl)valine in hemoglobin, although the amounts (as with fotemustine) showed considerable interindividual variation. It appears that the measurement of (hydroxyethyl)valine in hemoglobin may be a suitable monitor of exposure to hydroxyethylating agents during (chloroethyl)nitrosourea chemotherapy.

Alkylation↗
PubMedDate not supplied

Nucleotide sequence of epidermal growth factor cDNA predicts a 128,000-molecular weight protein precursor.

Epidermal growth factor (EGF) has a profound effect on the differentiation of specific cells in vivo, and has been shown to be a potent mitogenic factor for a variety of cultured cells, of both ectodermal and mesodermal origin (see ref. 1 for review). This 53-amino acid polypeptide of known sequence contains six cysteine residues, which are thought to form three intrachain disulphide bonds. Urogastrone, a polypeptide bearing anti-gastric secretory activity isolated from human urine, which is presumably synthesized in submandibular and Brunner's glands, shares extensive sequence homology (70%) with EGF and may represent the human EGF equivalent. Here we present the sequence of a mouse EGF cDNA clone, which suggests that EGF is synthesized as a large protein precursor of 1,168 amino acids. Our data indicate that the discrepancy between EGF levels in male and female mouse submaxillary glands (MSGs) is due to different EGF mRNA levels in these tissues, and suggest that precursor EGF processing may differ from that described previously for other polypeptide hormones.

Amino Acid Sequence↗
PubMedDate not supplied

Human epidermal growth factor receptor cDNA sequence and aberrant expression of the amplified gene in A431 epidermoid carcinoma cells.

The complete 1,210-amino acid sequence of the human epidermal growth factor (EGF) receptor precursor, deduced from cDNA clones derived from placental and A431 carcinoma cells, reveals close similarity between the entire predicted v-erb-B mRNA oncogene product and the receptor transmembrane and cytoplasmic domains. A single transmembrane region of 23 amino acids separates the extracellular EGF binding and cytoplasmic domains. The receptor gene is amplified and apparently rearranged in A431 cells, generating a truncated 2.8-kilobase mRNA which encodes only the extracellular EGF binding domain.

Amino Acid Sequence↗
PubMedDate not supplied

Insulin-like growth factor II precursor gene organization in relation to insulin gene family.

The insulin gene family, comprised of insulin, relaxin, insulin-like growth factors I and II (IGF-I and IGF-II) and possibly the beta-subunit of 7S nerve growth factor, represents a group of structurally related polypeptides whose biological functions have diverged. The IGFs, or somatomedins, constitute a class of polypeptides that have a key role in pre-adolescent mammalian growth (see ref. 4 for review). IGF-I expression is regulated by growth hormone and mediates postnatal growth, while IGF-II appears to be induced by placental lactogen during prenatal development. The primary structures of both human IGFs have been determined and are closely related. A polypeptide highly homologous to human IGF-II is secreted by the rat liver cell line, BRL-3A. As this polypeptide, termed multiplication stimulating activity (MSA), differs from human IGF-II by only five amino acid residues, MSA probably represents the rat IGF-II protein. Using molecular cloning techniques, we have isolated cDNA and chromosomal genes coding for the MSA and human IGF-II precursors, respectively. Our data, presented here, indicate that both MSA and human IGF-II are synthesized initially as larger precursor molecules. The deduced preprohormones both have molecular weights (MWs) of 20,100 and contain C-terminal propeptides of 89 amino acid residues, which we have named E-peptides. The organization of the IGF-II precursor gene is discussed in relation to that of other insulin gene family members.

Amino Acid Sequence↗
PubMedDate not supplied

Human insulin receptor and its relationship to the tyrosine kinase family of oncogenes.

We have deduced the entire 1,370-amino-acid sequence of the human insulin receptor precursor from a single complementary DNA clone. The precursor starts with a 27-amino-acid signal sequence, followed by the receptor alpha-subunit, a precursor processing enzyme cleavage site, then the beta-subunit containing a single 23-amino-acid transmembrane sequence. There are sequence homologies to human epidermal growth factor receptor and the members of the src family of oncogene products.

Amino Acid Sequence↗
PubMedDate not supplied

The excess cost of acute exacerbations of chronic bronchitis in patients aged 45 and older in England and Wales.

INTRODUCTION: Chronic Bronchitis is a serious and costly health problem. Prevalence is estimated at 45 per 10,000 persons in the United Kingdom. Approximately 120,000 Pounds would be saved for every 100 hospital admissions avoided. A reduction in acute exacerbations of chronic bronchitis (AECB), treatment failures, and subsequent hospital admission could have a significant impact on the burden of AECB borne by secondary care facilities in the UK National Health Service (NHS). OBJECTIVE: The aim of this study is to provide an economic assessment of the direct cost to the health care system associated with the management of chronic bronchitis and its acute exacerbations. DESIGN: A prevalence-based, excess-cost-of-illness analysis is undertaken from the perspective of the UK NHS. Disease prevalence data, primary health care resource utilization, hospital inpatient and outpatient resource utilization, and costs of health care were taken from a variety of data sources, including a large UK national survey of general practice (GP) consultations, the General Practice Research Database, a survey from a single NHS hospital trust, and the national health-care resource and cost statistics. RESULTS: From 1994 to 1995, approximately 233,000 cases of chronic bronchitis were detected in the persons aged 45 and older in the United Kingdom. Prevalence peaked at 204 per 10,000 in the group of subjects aged 75 to 84 years. During that same period, the total excess cost of primary care associated with AECB was calculated at 35.7 million Pounds. The largest component of primary care costs was the excess cost of all prescription medicines, which totaled 27.8 million Pounds. The excess cost attributed to antibacterial and respiratory prescription medications alone was estimated at 9 million Pounds. Excess costs attributed to GP consultations and hospital emergency room visits were 6.5 million Pounds and 1.3 million Pounds, respectively. The excess costs arising from inpatient hospital episodes included 8.3 million Pounds for hospital admissions, 660,000 Pounds for outpatient costs, and 225,000 Pounds for day care. CONCLUSIONS: These results suggest that improving the management of AECB with the objective of reducing the number of AECB treatment failures and the associated hospital admissions could significantly reduce expenditures by the UK NHS.

Aged↗
PubMedDate not supplied

Cryopreserved red blood cells for pediatric transfusion. Frozen storage of small aliquots in polyvinyl chloride (PVC) plastic bags.

Human nonrejuvenated and rejuvenated red bood cells were prepared for cryopreservation and subsequent pediatric transfusion. Glycerol was added to the red blood cells in the primary polyvinyl chloride plastic collection bag to achieve a concentration of 40 per cent W/V. The red blood cells were concentrated by centrifugation, and the supernatant glycerol was discarded. Each glycerolized unit was divided into four equal aliquots in the individual 600-ml bags of a dry quadruple polyvinyl chloride plastic system, and each aliquot was frozen and stored at -80 C. After thawing, sodium chloride solutions were used to wash the aliquots in the IBM Blood Processor 2991-1 or 2991-2 or the Haemonetics Blood Processor 115, and the washed aliquots were stored in a sodium chloride-glucose-phosphate solution at 4 C for 24 hours. Freeze-thaw recovery of the red blood cells was about 97 per cent, and freeze-thaw-wash recovery was about 84 per cent. Twenty-four-hour posttransfusion survival values were about 92 per cent for both nonrejuvenated and indated-rejuvenated red blood cells. Nonrejuvenated red blood cells, those frozen within three to five days of collection without biochemical modification, had normal oxygen transport function at the time of transfusion; rejuvenated red blood cells, those biochemically treated with PIGPA Solution A after three to five days of storage at 4 C, had improved oxygen transport function at the time of transfusion.

Adenosine Triphosphate↗
PubMedDate not supplied

A comparison of methods of determining the 100 percent survival of preserved red cells.

Studies were done to compare three methods to determine the 100 percent survival value from which to estimate the 24-hour posttransfusion survival of preserved red cells. The following methods using small aliquots of 51Cr-labeled autologous preserved red cells were evaluated: First, the 125I-albumin method, which is an indirect measurement of the recipient's red cell volume derived from the plasma volume measured using 125I-labeled albumin and the total body hematocrit. Second, the body surface area method (BSA) in which the recipient's red cell volume is derived from a body surface area nomogram. Third, an extrapolation method, which extrapolates to zero time the radioactivity associated with the red cells in the recipient's circulation from 10 to 20 or 15 to 30 minutes after transfusion. The three methods gave similar results in all studies in which less than 20 percent of the transfused red cells were nonviable (24-hour posttransfusion survival values of between 80-100%), but not when more than 20 percent of the red cells were nonviable. When 21 to 35 percent of the transfused red cells were nonviable (24-hour posttransfusion survivals of 65 to 79%), values with the 125I-albumin method and the body surface area method were about 5 percent lower (p less than 0.001) than values with the extrapolation method. When greater than 35 percent of the red cells were nonviable (24-hour posttransfusion survival values of less than 65%), values with the 125I-albumin method and the body surface area method were about 10 percent lower (p less than 0.001) than those obtained by the extrapolation method.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

The relation between dominance, anger, and hormones in normally aging men: results from the Massachusetts Male Aging Study.

This paper examines the relation of two personality characteristics (dominance and anger) to hormones in normally aging men. The relation of the Jackson Personality Research Form E Dominance subscale and the Spielberger Anger Expression scale to serum levels of 17 endocrine variables, including testosterone (T) and dihydrotestosterone (DHT), cortisol, and prolactin, was examined in 1709 men aged 39 to 70 years randomly sampled from the Boston Metropolitan Statistical Area. Canonical correlation analysis resulted in the identification of a personality profile characterized as dominant with some aggressive behavior that tends to correlate with a hormonal pattern labeled the "availability of androgens." These results partially support previous findings in animals, adolescents, and criminal populations that "aggressive dominance" is related to testosterone.

Adult↗