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Biomedical subjects

K Buck

Publications and source records attributed to K Buck.

At least 19 recordsLinked to original sources
PubMed2002

Health care utilization patterns of Russian-speaking immigrant women across age groups.

The collapse of the Soviet Union in 1989 substantially increased the numbers of refugees and immigrants to the United States from the former Soviet Union. Little research has been conducted with this population although studies found that immigrant's access to health care services are based on patterns of utilization in their countries of origin. The purpose of this study was to learn about the experiences of immigrant women from three former Soviet Republics (Belarus, Russia, and Ukraine) with women's health care services. Three focus groups of women were formed; ages 20-30, 37-46, and 60 and above. A focus-group guide was used to learn about their health care experiences. These immigrant women did access health care services based on patterns of utilization in their countries of origin. Greater understanding of immigrant populations' cultural patterns of health care utilization is needed to improve access and delivery of health care services to these populations.

Journal Article↗
PubMed2002

Multiple cross mapping (MCM) markedly improves the localization of a QTL for ethanol-induced activation.

This study examines the use of multiple cross mapping (MCM) to reduce the interval for an ethanol response QTL on mouse chromosome 1. The phenotype is the acute locomotor response to a 1.5-g/kg i.p. dose of ethanol. The MCM panel consisted of the six unique intercrosses that can be obtained from the C57BL/6J (B6), DBA/2J (D2), BALB/cJ (C) and LP/J (LP) inbred mouse strains (N > or = 600/cross). Ethanol response QTL were detected only with the B6xD2 and B6xC intercrosses. For both crosses, the D2 and C alleles were dominant and decreased ethanol response. The QTL information was used to develop an algorithm for sorting and editing the chromosome 1 Mit microsatellite marker set (http://www.jax.org). This process yielded a cluster of markers between 82 and 85cM (MGI). Evidence that the QTL was localized in or near this interval was obtained by the analysis of a sample (n = 550) of advanced cross heterogenous stock animals. In addition, it was observed that one of the BXD recombinant inbred strains (BXD-32) had a recombination in the interval of interest which produced the expected change in behavior. Overall, the data obtained suggest that the information available within existing genetic maps coupled with MCM data can be used to reduce the QTL interval. In addition, the MCM data set can be used to interrogate gene expression data to estimate which polymorphisms within the interval of interest are relevant to the QTL.

Animals↗
PubMed2000

Mapping quantitative trait loci that regulate sensitivity and tolerance to quinpirole, a dopamine mimetic selective for D(2)/D(3) receptors.

Acute sensitivity and tolerance to quinpirole (a dopamine mimetic with selectivity for D(2)/D(3) dopamine receptors) were evaluated in the C57BL/6J and DBA/2J inbred strains of mice, 24 of their BXD recombinant inbred strains, and 233 F(2) mice. Baseline locomotor activity, locomotor activity following 0.03 mg/kg quinpirole (and 0. 01 mg/kg in BXD mice), body temperature following 1 mg/kg quinpirole, and hypothermic tolerance following 2 or 3 days of quinpirole administration were evaluated. Quantitative trait locus (QTL) analysis was employed to identify genetic determinants of baseline locomotor activity and five behavioral responses to quinpirole. We examined correlated allelic variation in genetic markers of known chromosomal location with variation in each of these phenotypes. We definitively mapped a QTL on Chromosome (Chr) 9 linked to the D(2) dopamine receptor gene, Drd2, for hypothermic sensitivity to quinpirole, and identify a suggestive QTL in the same chromosomal region for tolerance to quinpirole after repeated treatments. Suggestive QTLs were also identified on Chr 19 for sensitivity and tolerance to quinpirole-induced hypothermia and for baseline locomotor activity; on Chr 15 for locomotor sensitivity to quinpirole; and on Chr 13 and 5 for baseline locomotor activity. Our results indicate that genetic differences in quinpirole sensitivity and tolerance are associated with QTLs near Drd2, and that baseline locomotor activity is associated with a suggestive QTL in proximity to the dopamine transporter gene Dat1. These data suggest that the genes influencing locomotor activity, dopamine mimetic sensitivity, and tolerance do not overlap completely.

Animals↗
PubMed1999

Quantitative trait loci affecting risk for pentobarbital withdrawal map near alcohol withdrawal loci on mouse chromosomes 1, 4, and 11.

Barbiturate dependence is associated with the development of physiological dependence (withdrawal), tolerance, or a maladaptive pattern of drug use. Analysis of strain and individual differences with animal models for physiological dependence liability are useful means to identify potential genetic determinants of liability in humans. Behavioral and quantitative trait locus (QTL) mapping analyses were conducted with mice that are resistant versus sensitive to pentobarbital withdrawal. With a multistage genetic mapping strategy, a pentobarbital withdrawal QTL (Pbw1) was mapped to the distal region of mouse Chromosome (Chr) 1 and may be identical to an alcohol withdrawal QTL mapped to this chromosomal region. Two suggestive QTLs for pentobarbital withdrawal, both in proximity to QTLs definitely mapped for alcohol withdrawal, were also tentatively identified. These were on Chr 11 in proximity to a gene cluster including several members of the GABAA receptor gene family, and on Chr 4 near a locus associated with beta-carboline-induced seizure severity. These data represent the first detection and mapping of loci influencing risk for physiological dependence on barbiturates, and suggest the involvement of common genes in physiological dependence on pentobarbital and alcohol.

Animals↗
PubMed1999

Older observers' tolerance of optical blur: age differences in the identification of defocused text signs.

To determine if visual aging affects the ability to identify blurred text signs in daytime or nighttime viewing conditions, the photopic and mesopic legibility thresholds of young and old adult observers were compared at three levels of optically induced acuity (Experiment 1). For both age groups, legibility was reduced by nighttime luminance and degraded acuity. Surprisingly, older observers were better than younger ones in identifying defocused (optically blurred) text in both daytime and nighttime conditions. In Experiment 2, older observers were also superior to younger ones in identifying defocused standard and spatially matched novel text signs. These findings indicate that older observers' tolerance of optical blur is a generic ability, rather than one explained by familiarity with the low-pass optical profile of specific signs. Consistent with the notion that factors beyond acuity contribute more importantly to text legibility for older than for younger observers, acuity was a stronger predictor of legibility thresholds in the younger group. Actual or potential applications of this research include the need to consider functional acuity in visual screening protocols and the design of text displays, as well as the utilization of compensatory letter-recognition training for older observers or others with diminished acuity.

Adolescent↗
PubMed1999

Pleomorphic hyalinized angiectatic tumor of soft parts.

Pleomorphic hyalinized angiectatic tumor of soft parts is a recently described neoplasm that most commonly affects the lower extremities. It is locally aggressive but has not been known to metastasize. This article presents a case of a softball-sized tumor on the dorsum of the foot that was identified as pleomorphic hyalinized angiectatic tumor of soft parts. Previously, it would have been misdiagnosed and treated as either a neurilemoma or a malignant fibrous histiocytoma.

Adult↗
PubMed1998

The effects of elevated intraabdominal pressure, hypercarbia, and positioning on the hemodynamic responses to laparoscopic colectomy in pigs.

BACKGROUND: This study investigated three factors postulated to be sources of physiological stress in laparoscopic surgery: hypercarbia, elevated intraabdominal pressure, and the steep Trendelenburg position. Our research was designed to define the effects of each of these potential stressors on hemodynamic responses observed during laparoscopic colectomy in pigs. METHODS: Twenty-four pigs were randomized into the following four groups, based on the method for obtaining surgical exposure while a colectomy or laparoscopic-assisted colectomy was performed: Open surgery (n = 6), CO2 pneumoperitoneum (n = 6), Helium pneumoperitoneum (n = 6), and abdominal wall Lifter (n = 6). The animals were paralyzed with minute ventilation adjusted. All animals underwent extensive pulmonary and hemodynamic monitoring with measurements of the following parameters: RR, Vt, minute ventilation, O2, sat, ETCO2, PVR, HR, MAP, CO, PAP, CVP, PCWP, SV, LVSWI, DO2, and VO2. The laparoscopic pigs were placed in the steep Trendelenburg position during surgery. RESULTS: The effect of a CO pneumoperitoneum was to increase PaCO2 PVR and cause an acidemia that could not be prevented by an increase in minute ventilation. Elevated intraabdominal pressure decreased UO. Both pneumoperitoneum groups had a fourfold increase in IVCP, a measure of intraabdominal pressure. Some of this increase was due to placement into the Trendelenburg position; IVCP increased to a lesser degree in the Lifter group. The steep Trendelenburg position caused significant increases in PAP, CVP, and PCWP; however, a contributory effect of elevated intraabdominal pressure cannot be ruled out. None of these procedures had any significant effect on the HR or MAP. There was a significant increase in CO in the CO2 and Lifter groups; however, when CO was controlled for HR effects, there was no significant effect on SV from any of these different procedures. LVSWI, DO2, and VO2 were not affected by any of the different exposure methods. CONCLUSIONS: The effects of laparoscopic surgery and open surgery on hemodynamic responses are minimal, and no one method is superior to another when performed in pigs that are healthy, hydrated, and hyperventilated to keep ETCO2 < 40. However, since elderly and sick patients have a lower threshold for physiologic decompensation, we can infer that the small hemodynamic changes noted in this study might become significant factors when surgery is performed on compromised patients. The finding that an abdominal wall lifting device causes the fewest metabolic and hemodynamic effects makes its use an important consideration when performing laparoscopic surgery in patients with cardiopulmonary compromise, hemodynamic instability, or any preexisting renal insufficiency.

Abdomen↗
PubMed1998

The specific problems of noise in military life.

In military life, noise has unusual characteristics and constitutes a serious hazard for hearing. Hearing impairments due to the exposure to weapon noises represent an important prejudice for the health of many soldiers. A special attention is given to (i) the "critical level", (ii) the frequency localization of the threshold shifts, (iii) the actual influence of the protective reflexes of the ear, (iv) the existence of delayed threshold shifts following impulse noise exposures, and (v) the interest of the medical treatment of the acoustic trauma. Damage risk criteria for weapon noises are compared: criteria using the (A-weighted) isoenergy principle represent the best present solution (LAeq = 85 dB). Specific problems related to the use of hearing protection are also discussed.

Auditory Threshold↗
PubMed1992

Multiple forms of prolactin receptor messenger ribonucleic acid are specifically expressed and regulated in murine tissues and the mammary cell line HC11.

The expression of PRL receptor mRNA in mouse tissues was studied. Seven PRL receptor transcripts of different sizes were found. The pattern of expression was tissue specific. The PRL receptor protein exists in isoforms of approximately 300 and 600 amino acids, which differ in the sequence and length of the cytoplasmic domain. Probes specific for the lower mol wt forms of the receptor hybridized to transcripts of 1.4, 2.4, 3.5, and 4.2 kilobases (kb), which were predominantly expressed in the liver and kidney. Among the three isoforms of the small form of the receptor, PR-3 was highly expressed, PR-2 was weakly expressed, and PR-1 was undetectable. Probes specific for the higher mol wt receptor form detected transcripts of 9 and 10 kb, expressed most strongly in the ovary, mammary gland, and kidney. An additional 8.3-kb transcript was expressed in the kidney. The PRL-responsive mouse mammary epithelial cell line HC11 expressed only the 9- and 10-kb receptor mRNAs, as did the mammary gland. The transcripts for the two PRL receptor forms were independently regulated during pregnancy and lactation in a tissue-specific manner. The expression of the small receptor form in the liver increased 7-fold during pregnancy and decreased during lactation. Its expression in the kidney remained constant. Expression of the larger receptor form increased 2.5-fold in the kidney during lactation, but remained constant in the mammary gland. In the ovary the expression of the large receptor form could be elevated 4-fold after induction of hyperovulation with FSH and hCG. Thus, in the mouse there are at least two forms of the PRL receptor regulated independently in different tissues.

Animals↗
PubMed1992

Parathyroid stimulation after bleeding in man.

A role for the PTH-calcium axis in the normal bone-marrow response to bleeding or erythropoietin administration has been demonstrated in rats. We studied 20 autologous blood donors, each donating two units of blood, who served as a human bleeding model. Fifteen patients completed the study. Blood donations were followed by a significant increase in serum intact PTH (2.15 +/- 0.67 to 2.81 +/- 0.84 pmol/l; p = 0.0003) and protein-corrected total calcium (2.43 +/- 0.09 to 2.49 +/- 0.08 mmol/l; p = 0.2). All the individual values remained within the normal range. PTH weakly correlated with the reticulocyte count, but not with the corrected serum calcium. We conclude that moderate bleeding in humans is followed by a physiological increase in serum PTH and calcium.

Adolescent↗
PubMed1991

Multiple human D5 dopamine receptor genes: a functional receptor and two pseudogenes.

Three genes closely related to the D1 dopamine receptor were identified in the human genome. One of the genes lacks introns and encodes a functional human dopamine receptor, D5, whose deduced amino acid sequence is 49% identical to that of the human D1 receptor. Compared with the human D1 dopamine receptor, the D5 receptor displayed a higher affinity for dopamine and was able to stimulate a biphasic rather than a monophasic intracellular accumulation of cAMP. Neither of the other two genes was able to direct the synthesis of a receptor. Nucleotide sequence analysis revealed that these two genes are 98% identical to each other and 95% identical to the D5 sequence. Relative to the D5 sequence, both contain insertions and deletions that result in several in-frame termination codons. Premature termination of translation is the most likely explanation for the failure of these genes to produce receptors in COS-7 and 293 cells even though their messages are transcribed. We conclude that the two are pseudogenes. Blot hybridization experiments performed on rat genomic DNA suggest that there is one D5 gene in this species and that the pseudogenes may be the result of a relatively recent evolutionary event.

Amino Acid Sequence↗
PubMed1987

Issues in establishing rural ophthalmic surgery centers.

Citizens of rural communities suffer from a lack of specialized medical care. A large percentage of these citizens are elderly people who require more eye care than the rest of the population. These factors point to a need for outreach rural ophthalmic surgery centers. The author has been involved in the establishment of satellite ophthalmic outpatient surgical centers in the outlying communities of Arizona and shares insight into the procedure through a discussion of the various issues encountered in this experience.

Aged↗