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Biomedical subjects

K Hill

Publications and source records attributed to K Hill.

At least 19 recordsLinked to original sources
PubMed1996

The demography of menopause.

Menopause marks a time of dramatic hormonal and often social change for women. Both risk factors and health needs are likely to change as women pass through menopause. This paper examines the demographic characteristics of the world population of menopausal and post-menopausal women, and also examines the implication of menopause for mortality risks. The numbers of women involved are large. Using age 50 as a proxy for menopause, about 25 million women pass through menopause each year, and we estimate that in 1990 there were 467 million post-menopausal women in the world, with an average age of about 60 years. By 2030, the world population of menopausal and postmenopausal women is projected to increase to 1.2 billion, with 47 million new entrants each year. The mortality implications of menopause are also substantial. Ratios of female to male mortality risks from all causes and from all major cause groups except neoplasms decline to low levels around menopause or shortly thereafter, and then rise again to near unity. This pattern is taken as evidence that the female reproductive period is broadly protective of health, but that this protection disappears after menopause. The main protective effect is through reduced risk of cardiovascular disease mortality, partially offset by increased risks of cancer mortality, particularly of the breast and endometrium.

Adult↗
PubMed1996

Pediatric locum tenens provided by an academic center.

BACKGROUND: Locum tenens, the use of a substitute physician to replace a physician who must be temporarily absent from his practice, is widely accepted in the United States. Locum tenens has not previously been described or studied in pediatric practice. OBJECTIVE: This article describes a locum tenens service for Colorado and Wyoming pediatricians provided by the Division of General Pediatrics and Pediatric Emergency Medicine at the University of Colorado School of Medicine and the Children's Hospital of Denver. An analysis and an evaluation of the program are presented, and implications are discussed. METHODS: All program data were prospectively collected and tabulated and later analyzed for the period from July 1, 1994, through June 30, 1995. A survey of all physicians using the Pediatric Locum Tenens Service was conducted within 2 months of service to evaluate the program and to refine the orientation, credentialing, and evaluation processes. RESULTS: During the year, 35 pediatricians (14% of pediatricians in Colorado and Wyoming) made 97 requests for 398 days of locum tenens coverage. Coverage was used for vacation (85%), medical education (10%), medical leave (3%), and family matters (2%). Solo and rural pediatricians used the service at a higher rate than pediatricians in group or urban practices. Eighty-six percent had never used locum tenens coverage before because of either the expense (67%) or their unwillingness to trust their practices to physicians or services with whom or with which they were unfamiliar (50%). The majority (83%) were willing to pay an amount for locum tenens equal to the net income derived from the locum tenens coverage in the practice. None indicated a willingness to pay more than that. Referrals and admissions to the Children's Hospital from the pediatricians who used the service increased by 22% during the study period compared with the preceding year, whereas referrals and admissions increased by 9% among all other Colorado and Wyoming pediatricians. All pediatricians completed surveys, and satisfaction with the locum tenens pediatricians, charges, and program administration was high. Their suggestions are described. DISCUSSION: The following topics are discussed: (1) the economics of pediatric locum tenens; (2) the use of a locum tenens service as a physician relations program by children's hospitals or academic departments of pediatrics; (3) guidelines for orientation of locum tenens pediatricians; and (4) a proposed evaluation and credentialing process for locum tenens physicians.

Colorado↗
PubMed1995

Structural organization of a Bacillus subtilis operon encoding menaquinone biosynthetic enzymes.

Menaquinone (MK) is a non-protein component of the Bacillus subtilis (Bs) electron transport chain synthesized from chorismate through a series of MK-specific reactions. The genes encoding biosynthesis of the naphthoquinone ring of MK are clustered at 273 degrees on the Bs chromosome. A 3.9-kb region capable of rescuing men mutants blocked in the early stages of MK biosynthesis was sequenced and found to contain three major open reading frames (ORFs). The first ORF (menF) has a predicted size of 51.8 kDa and 34% amino-acid identity with the isochorismate synthases of Escherichia coli (EntC) and Aeromonas hydrophila (AmoA), ORF2 (menD) a predicted size of 60.2 kDa and 21% identity with MenD of E. coli. ORF3 has a predicted size of 21.4 kDa and 29% identity to triacylglycerol lipase of Psychrobacter immobilis. No sequence corresponding to menC was identified. Plasmid integrational studies of the men gene cluster had suggested the presence of promoters secondary to the previously identified p1 men promoter. Sequence analysis revealed a putative promoter region upstream from ORF3.

Bacillus subtilis↗
PubMed1995

Treatment of childhood diarrhea in rural Egypt.

The Egypt National Control of Diarrheal Diseases Project, implemented between 1983 and 1991, is widely regarded as one of the most successful national oral rehydration programs. Data from a longitudinal household survey conducted in 1990-91 in rural Egypt indicate substantial increases in both knowledge and use of oral rehydration salts during the 1980s. However, the same data show that treatment of acute diarrheal episodes is still far from optimal. In particular, the use of oral rehydration during diarrheal episodes is far from universal, the prescription of antibiotics is still too frequent, and antidiarrheal drugs of no therapeutic value are still widely used. Analysis of the factors associated with different treatment patterns shows that children with severe diarrhea, those aged 6-23 months and those from poor households were more likely to be given ORS; boys were somewhat less likely to receive ORS than girls, but mother's education showed no consistent effects. The type of treatment received is strongly influenced by the source of care. Government clinics are more likely than private physicians or pharmacies to prescribe ORS, whereas children taken to the latter two sources of care are more likely to be given antibiotics and antidiarrheals. To improve diarrhea treatment patterns in Egypt, not only must the public service educational campaign be reinstated and strengthened, but training programs must also be targeted at the treatment practices of private physicians.

Child Health Services↗
PubMed1995

Working with traumatic material: effects on Holocaust Memorial Museum staff.

Preparation for the opening of the United States Holocaust Memorial Museum in Washington, D.C., in April 1993, exposed workers to potentially disturbing personal artifacts of Holocaust victims and other reminders of the horrors of the Holocaust. The process of psychological consultation is described, and the resultant approaches to interventions designed to lower distress among museum workers and volunteers are discussed.

Adaptation, Psychological↗
PubMed1995

The use, efficacy and monitoring of artificial nutritional support in a teaching hospital.

The implementation of circulated guidelines has been audited, by assessing the extent to which nutritional goals were set and achieved and recording the levels of morbidity as a result of complications. Adults receiving artificial nutritional support were studied over a six month period. Nutritional assessment was used to determine adequacy of prescription and efficacy of the support. Energy requirements were retrospectively calculated and compared with prescriptions and actual intakes. Complications and interruptions to the regimens which resulted in lost feeding time were recorded, as were patient outcomes. Nutrient prescriptions were inadequate, delivery of prescriptions was incomplete and thus nutrient supply inadequate.

Aged↗
PubMed1994

A flowchart-oriented interview language (FOIL) and its application to a low-back pain interview system.

The flowchart-oriented interview language (FOIL) is a computer programme that converts flowchart information into C programming language code. The programme was written to simplify development and maintenance of the Birmingham Back Pain Interview System. In addition FOIL gives the user of the interview system the flexibility of changing the questionnaires to suit their local needs. FOIL may be used for any flowchart-oriented problem. The flowchart specification and the questions are defined in ASCII character files.

Algorithms↗
PubMed1994

Diarrhoeal disease, oral rehydration, and childhood mortality in rural Egypt.

The Egyptian National Control of Diarrhoeal Diseases Project (NCDDP) is reported to have had great success in improving case management of diarrhoea, and in reducing diarrhoea-related mortality among children, while deaths due to other causes have remained unchanged. Recent reports have claimed that with this dramatic decline in diarrhoea mortality, respiratory infection is now the main cause of child death in Egypt. As a result, the degree of commitment to control of diarrhoeal disease activities has been greatly reduced. We present new data from a large prospective study that confirms much of the success of the NCDDP, but which questions the extent of the claimed project impact on mortality. Child mortality has declined greatly over the past decade. However, deaths from other causes have declined almost as much as those from diarrhoea, and most importantly, diarrhoea remains the main cause of death among children. Our discussion demonstrates the need for appropriate methodology in evaluating the mortality impact of an intervention, and to the very great importance of reinvigorating control of diarrhoeal diseases activities in Egypt.

Child, Preschool↗
PubMed1993

Further analysis of the cognitive effects of tetrahydroaminoacridine (THA) in Alzheimer's disease: assessment of attentional and mnemonic function using CANTAB.

Results of a placebo controlled cross-over trial (N = 89) of the anticholinesterase drug THA as a treatment for dementia of the Alzheimer's type (DAT) are reported, with reference to previous trials of the drug and the cholinergic hypothesis of aging and dementia. Using computerised tests sensitive to specific aspects of memory and attention, evidence is found for improvements in attentional function rather than memory, in patients with mild to moderate DAT. Although these improvements were significant, they were small and restricted to certain tests of attentional function. Nevertheless, they add to the growing body of evidence that the cholinergic system is involved in the control of attentional processes. The results will be relevant to future investigations into the therapeutic effects of enhancement of the cholinergic system in DAT sufferers.

Aged↗
PubMed1993

Neurological manifestations of baclofen withdrawal.

Baclofen is a central nervous system agent that is commonly used for the treatment of muscle spasticity in spinal cord injury patients. Acute withdrawal of this medication can induce the development of neurological symptoms, including seizure disorder, psychosis, hallucinations and visual disturbances. We report 3 cases of acute central nervous system symptoms that developed in spinal cord injury patients. Each patient had been chronically maintained on a baclofen regimen to control muscle spasticity. Symptoms developed shortly after baclofen therapy was interrupted following genitourinary surgery. It is important that urologists become familiar with the symptomatology of baclofen withdrawal, the methods of its prevention and the appropriate therapy should the syndrome develop.

Adult↗
PubMed1992

Yeast KRE2 defines a new gene family encoding probable secretory proteins, and is required for the correct N-glycosylation of proteins.

We have cloned, sequenced and disrupted the KRE2 gene of Saccharomyces cerevisiae, identified by killer-resistant mutants with a defective cell wall receptor for the toxin. The KRE2 gene is close to PHO8 on chromosome 4, and encodes a predicted 49-kD protein, Kre2p, that probably enters the secretory pathway. Haploid cells carrying a disruption of the KRE2 locus grow more slowly than wild-type cells at 30 degrees, and fail to grow at 37 degrees. At 30 degrees, kre2 mutants showed altered N-linked glycosylation of proteins, as the average size of N-linked outer chains was reduced. We identified two other genes, YUR1 on chromosome 10, and KTR1 on chromosome 15, whose predicted products share 36% identity with Kre2p over more than 300 amino acid residues. Yur1p has an N-terminal signal sequence like Kre2p, while Ktr1p has a predicted topology consistent with a type 2 membrane protein. In all cases the conserved regions of these proteins appear to be on the lumenal side of secretory compartments, suggesting related function. KRE2, KTR1 and YUR1 define a new yeast gene family.

Amino Acid Sequence↗
PubMed1992

Blushing as a function of audience size.

Almost no experimental analysis of blushing has been done since Darwin's observations in 1872. Forty-eight college women watched a videotape intended to elicit blushing, and a videotape not intended to elicit blushing, but elicit physiological responses. A subject was alone, or with one or four persons present. Blushing, which was measured directly with a photoplethysmograph probe on the cheek, was greater during the blushing than nonblushing stimulation. Blushing increased as audience size increased from one to four, but not from zero to one. Audience size and kind of stimulation interacted statistically. Similar results were obtained with ear coloration, cheek temperature, and skin conductance responses, although confidence levels were lower. Cheek coloration and temperature were significantly correlated during nonblushing stimulation, and the zero and one audience conditions, but not during the four audience condition, when blushing was greatest. These results may be placed within the context of emotional effects of audience size generally, including stuttering and speech disturbance, disruption of learning, and self-reported tension.

Adult↗
PubMed1991

Dynamic interplay between two copper-titrating components in the transcriptional regulation of cyt c6.

The algal plastidic cytochrome c (cyt c6) is a biochemical equivalent of the copper-containing protein plastocyanin in photosynthetic electron transfer. But generally, cyt c6 accumulates and functions only under conditions (e.g. Cu-deficiency) where holoplastocyanin cannot be synthesized. In studying the regulation of Chlamydomonas reinhardtii cyt c6 expression by Cu we have determined that repression of cyt c6 accumulation occurs at the transcriptional level, and specifically in response to Cu as the metal ion regulator. Complete and sustained repression of cyt c6 transcription requires approximately 9 x 10(6) Cu ions in the medium/cell. Based on the estimated plastocyanin content of algal cells (8 x 10(6) molecules/cell) and the observation that lower ratios of Cu per cell result in only transient repression of cyt c6 transcription, we propose that Cu-dependent transcriptional repression of the gene encoding cyt c6 requires a Cu-binding factor which is titrated by Cu only after the alternate electron transfer catalyst, plastocyanin, has accumulated to the stoichiometry required for photosynthesis. The precise and highly metal-specific, autoregulatory control of cyt c6 levels--directly by Cu, and indirectly by holoplastocyanin--is in keeping with the functional role of cyt c6 as an alternate, although perhaps less preferred, electron transfer catalyst.

Blotting, Northern↗
PubMed1991

A multicenter, prospective study of fetal outcome following accidental carbon monoxide poisoning in pregnancy.

We report the results of the first prospective, multicenter study of acute carbon monoxide (CO) poisoning in pregnancy. We collected and followed cases of CO poisoning occurring during pregnancy between December 1985 and March 1989. The sources of CO were malfunctioning furnaces (n = 16), hot water heaters (n = 7), car fumes (n = 6), and methylene chloride inhalation (n = 3). Pregnancy outcome was adversely affected in 3 of 5 pregnancies with severe toxicity; two stillbirths, and one cerebral palsy with tomographic findings consistent with ischemic damage. All adverse outcome occurred in cases treated with high flow oxygen, whereas the 2 cases of severe toxicity with normal outcomes followed hyperbaric oxygen therapy. All 31 babies exposed in utero to mild or moderate CO poisoning exhibited normal physical and neurobehavioral development. Severe maternal CO toxicity was associated with significantly more adverse fetal cases when compared to mild maternal toxicity (P less than 0.001). It is concluded that while severe CO poisoning poses serious short- and long-term fetal risk, mild accidental exposure is likely to result in normal fetal outcome. Because fetal accumulation of CO is higher and its elimination slower than in the maternal circulation, hyperbaric oxygen may decrease fetal hypoxia and improve outcome.

Abnormalities, Drug-Induced↗
PubMed1990

Isolation and characterization of a complementary DNA clone for an algal pre-apoplastocyanin.

We have isolated a cDNA clone for the Chlamydomonas reinhardtii pre-apoplastocyanin. The sequence contains codons for the complete pre-protein including a two-domain, lumen-targeting transit sequence and the mature apoprotein. The transit sequence (47 amino acids) is the shortest one described for chloroplast lumenal proteins, and like other C. reinhardtii lumen-targeting transit sequences appears to lack an uncharged amino-terminal domain usually present in plant lumen-directing sequences. The mature protein is deduced to be 98 amino acids in length and shows highest primary sequence similarity (74-76% identity) to other unicellular algal plastocyanins. Southern hybridization analysis of C. reinhardtii genomic DNA indicates the presence of a single nuclear gene, as is the case for all other plastocyanin genes characterized to date, although the algal gene might be interrupted. Codon usage in this gene reflects the high GC content of C. reinhardtii nuclear DNA, but is more highly biased than that found in the C. reinhardtii copper-repressible gene for the functionally equivalent pre-apocytochrome c552 (perhaps contributing to the more efficient synthesis in vivo of plastocyanin over cytochrome c552). The deduced physical properties of this plastocyanin are compared to those of the C. reinhardtii plastidic cytochrome c552.

Amino Acid Sequence↗
PubMed1990

A nucleotide that enhances the charging of RNA minihelix sequence variants with alanine.

We showed earlier that a single G3.U70 base pair within the amino acid acceptor helix is a major determinant of the identity of tRNA(Ala). In addition, we demonstrated that an RNA hairpin minihelix that recreates the 12 base pair acceptor-T psi C stem of tRNA(Ala) is also aminoacylated in a G3.U70-dependent manner. Determinants for efficient aminoacylation at pH 7.5 have been further investigated with minihelix substrates that have sequence variations at 3.70 and other locations. Although a U,U mismatch and other 3.70 nucleotide alternatives to G.U were recently proposed by others as also important for alanine acceptance, neither that mismatch nor any of four other 3.70 nucleotide combinations confer aminoacylation in vitro with alanine, even with substrate levels of enzyme. In contrast, permutations of the so-called discriminator nucleotide N73 (at position 73) strongly modulate, but do not block, aminoacylation of those substrates that encode G3.U70. In particular, the efficiency of G3.U70-dependent aminoacylation with alanine is strongly enhanced by having the wild-type A73. The effect of N73 alone can explain most of the difference in aminoacylation efficiency of a G3.U70-containing tRNA and a minihelix substrate whose sequences vary significantly from their tRNA(Ala) counterparts. Comparison with earlier work suggests that the substantial modulating effect of N73 is partly or completely obscured when N73 tRNA variants are expressed as amber suppressors in vivo.

Alanine-tRNA Ligase↗