Search PubMed⌕ Search

Biomedical subjects

K Hunter

Publications and source records attributed to K Hunter.

At least 73 records · Page 4Linked to original sources
PubMed1989

Altered glucose metabolism in microvessels from patients with Alzheimer's disease.

Microvessels isolated from temporal cortex of patients with Alzheimer's disease showed decreased uptake of glucose when compared with vessels from age-matched or young control subjects. This was due to decreased hexokinase activity in the Alzheimer samples, as determined by ion exchange chromatography. This finding was confirmed independently by determination of the phosphorylation constant for hexokinase, K3, using positron emission tomography. The results suggest that Alzheimer's disease may result from a global defect in brain energy metabolism.

Adult↗
PubMed1988

Determination of diastereoisomers of bromadiolone, an anticoagulant rodenticide, in animal tissues by high-performance liquid chromatography.

Two components isolated by semi-preparative normal phase high-performance liquid chromatography (HPLC) of bromadiolone reference material were tentatively identified as diastereoisomeric forms. Examination by mass spectroscopy confirmed this identification and supporting evidence was provided by identical UV fluorescence characteristics. The separated isomers were used to examine the chromatographic properties of bromadiolone in ion-pair, ion-suppression and weak ion-exchange HPLC modes. Conditions suitable for the analytical determination of the individual diastereoisomers were established for each mode. The influence of mobile phase pH on the resolution of coumarin-based rodenticides by weak ion-exchange HPLC on an aminopropyl-bonded phase was studied. Clean-up techniques for the determination of residues of bromadiolone in animal tissue extracts were compared. A combined gel permeation and adsorption chromatographic procedure was preferred for sensitive assay; it permitted the use of either fluorescence or UV detection. The lower practical limit of determination of each isomer in animal tissues was 0.005 mg kg-1 using UV detection and 0.0005 mg kg-1 using fluorescence detection.

4-Hydroxycoumarins↗
PubMed1988

Rett syndrome: a survey of North American patients.

Parents of 63 North American girls with Rett syndrome filled out retrospective questionnaires in a project of the International Rett Syndrome Association, a parent group. No consistent pattern was revealed of possible etiological factors related to environmental insults; however, additional information gathered supported a genetic etiology. The survey included one pair of identical twins and one child with consanguineous parents. There were 46 male sibs and 34 female sibs. These data weigh against any theory relating etiology to a gene on the X chromosome which is lethal to males in utero. Figures were gathered on a number of clinical items. These were: onset of symptoms between 6 and 18 months of age, 83%; autistic withdrawal, 73%; never walked independently, 23%; hyperventilators with abdominal swelling, 63%; night laughter, 83%. The average age of walking of those who walked was 19 months and the average onset of seizure disorders was between 3 1/2 and 4 years of age. This paper ends by discussing the limitations of a parent questionnaire.

Adolescent↗
PubMed1988

Role of the International Rett Syndrome Association.

Since 1984, the International Rett Syndrome Association has brought together families of girls with Rett syndrome, disseminated information about the syndrome, and supported research efforts. Through its computerized records, the Association can match parents most able to provide support for one another, refer parents to physicians familiar with Rett syndrome, keep accurate statistical records of the disease, and connect researchers with subjects willing to participate in investigations. The Association helps families adjust emotionally and practically to living with a Rett syndrome patient and works toward long-term answers by promoting understanding and improved treatment for the condition.

Adaptation, Psychological↗
PubMed1987

Rett syndrome: parents' views about specific symptoms.

The International Rett Syndrome Association was founded in the spring of 1984 following the diagnosis of 10-year-old Stacie Hunter. The group began as an attempt to locate other parents of children who had shared the same long and tedious search for a diagnosis. The organization participated in a conference with the John F Kennedy Institute for Handicapped Children in January of 1985, where Dr Rett examined and confirmed 39 girls suspected to have the disorder. It was the first time ever that such a large gathering of Rett syndrome patients was held. The following November, 1985 brought an international team of 116 experts in the study of Rett syndrome to the Kennedy Institute for scientific investigation, at which time the International Rett Syndrome Association again sponsored a parent conference which brought together 70 affected girls and their families. The aims of the International Rett Syndrome Association are to 1) collect and disseminate accurate and objective information regarding the cause, identification, treatment, prediction, prognosis, analysis and prevention of Rett syndrome; 2) encourage research into Rett syndrome; 3) assist in identifying persons with Rett syndrome; 4) conduct other activities aimed at the prevention, treatment or eradication of Rett syndrome. Rett syndrome is a devastating disorder that affects the entire family for its lifetime. Parents develop many coping strategies in learning to live with Rett syndrome, and are often creative in their approaches. This paper addresses the many questions that parents often ask in their search to understand Rett syndrome and to make a better life for their children.(ABSTRACT TRUNCATED AT 250 WORDS)

Attitude to Health↗
PubMed1985

High-performance liquid chromatographic strategies for the determination and confirmation of anticoagulant rodenticide residues in animal tissues.

A comprehensive approach to the analysis of anticoagulant rodenticide residues in animal tissues based on high-performance liquid chromatography (HPLC) has been developed. Residues of warfarin, coumatetralyl, difenacoum, brodifacoum, bromadiolone, diphacinone and chlorophacinone were extracted with chloroformacetone (1:1, v/v). Extracts were cleaned-up by an integrated gel permeation and adsorption chromatographic procedure which divided the rodenticides into two groups. Residues were then determined and confirmed using normal-phase, ion-pair and weak ion-exchange HPLC techniques. Ion-pair gradient separation resolved all seven rodenticides in a single chromatographic analysis. UV detection methods were employed for all seven rodenticides. Use of a diode array detection system permitted additional confirmation of residues down to 0.1 mg kg-1 by matching UV spectra and derivatives of spectra. Sensitive fluorescence detection was possible for the coumarin-based rodenticides but not for diphacinone and chlorophacinone. Post-column pH-switching fluorescence detection methods were shown to be superior to other methods of fluorescence detection of coumarin-based rodenticides. Recoveries from spiked liver tissue were around 90% at levels from 0.05 to 1 mg kg-1. Detection limits of around 0.002 mg kg-1 for most rodenticides and of 0.01 mg kg-1 for warfarin could be achieved with animal tissue extracts.

Animals↗
PubMed1985

Proton magnetic resonance relaxation behavior of whole muscle with fatty inclusions.

This in vitro proton study of spin lattice (T1) and spin spin (T2) relaxation of muscle with storage-fat inclusions demonstrates slow exchange and lack of cross-relaxation between fat and water. Slow exchange causes biphasic T1 relaxation, but T2 relaxation is paradoxically uniphasic due to the nearly equal T2 values for both fractions. By careful dehydration and fat extraction, the relaxation information was deconvolved into water, fat, and protein contributions. The biphasic T1 decay has a short component due to lipid and a long component due to the water-protein combination. The fat content of muscle can be measured from the relative amplitude of the two T1 components or directly from the T2 relaxation time.

Adipose Tissue↗
PubMed1984

Reversed-phase ion-pair liquid chromatographic determination of chlorophacinone residues in animal tissues.

A sensitive and specific high-performance liquid chromatographic method for the identification and quantitation of chlorophacinone in animal tissues has been developed. Residues were extracted with chloroform-acetone (1:1, v/v). Clean-up of extracts was accomplished with a combined gel permeation-adsorption chromatographic procedure using Bio-Beads SX-3 and incorporating an on-line Sep-Pak silica cartridge. Residues were determined by ion-pair liquid chromatography, with the tetrabutylammonium ion as counter-ion, using a fixed-wavelength UV detector at 280 nm or a diode array detector at 285 nm. Recoveries from spiked liver tissue were around 90% at levels from 0.05 to 1 mg kg-1. A detection limit of 0.001 mg kg-1 could be achieved in animal tissues. The diode array detector confirmed identification by matching spectra for residues down to 0.1 mg kg-1 and below this level by multi-wavelength monitoring.

Animals↗
PubMed1983

Determination of coumarin anticoagulant rodenticide residues in animal tissue by high-performance liquid chromatography. I. Fluorescence detection using post-column techniques.

A multi-residue method was developed for the determination of the rodenticides warfarin, coumatetralyl, bromadiolone, difenacoum and brodifacoum in animal tissues by high-performance liquid chromatography with fluorescence detection. Extracts were cleaned-up by gel permeation chromatography on Bio-Beads SX-3 and residues determined by normal and reversed-phase high-performance liquid chromatography using post-column pH-switching, with chloroform -sec.-butylamine and borate buffer (pH 10.4) respectively, to maximise the native fluorimetric responses. Confirmation of identification was possible by re-chromatographing extracts in the absence of the post-column reagent. Chloroform-acetone (1:1) was significantly better than chloroform for the extraction of residues of these rodenticides from liver tissues. Recoveries from spiked liver tissue were generally greater than 90% at levels of 0.05-1 mg kg-1. Detection limits in animal tissues of 0.002 mg kg-1 for coumatetratyl, difenacoum and brodifacoum, 0.01 mg kg-1 for bromadiolone and 0.02 mg kg-1 for warfarin and could be routinely achieved.

Animals↗
PubMed1983

Determination of coumarin anticoagulant rodenticide residues in animal tissue by high-performance liquid chromatography. II. fluorescence detection using ion-pair chromatography.

A high-performance liquid chromatographic method was developed for the determination of warfarin, coumatetralyl, bromadiolone, difenacoum and brodifacoum in animal tissues using fluorescence detection. Ion-pair chromatography, with the tetrabutylammmonium ion as counter-ion, was used to take full advantage of their native fluorescence. Detection limits in liver tissue after gel permeation clean-up were 0.002 mg kg-1 for coumatetralyl, difenacoum and bromdifacoum, 0.008 mg kg-1 for bromadiolone, and 0.01 mg kg-1 for warfarin.

Animals↗
PubMed1983

Prenatal screening of pregnant women for infections caused by cytomegalovirus, Epstein-Barr virus, herpesvirus, rubella, and Toxoplasma gondii.

A service-oriented screening program for serologic detection of viral and parasitic infections during gestation is described for three different population groups. Significance of a determination of primary cytomegalovirus infection is documented. A screening program for detection of immunity to rubella is recommended, but the feasibility of similar programs for herpes simplex virus and Epstein-Barr virus warrants further study. Because of the low frequency of toxoplasmosis, education of patients instead of screening may be appropriate.

Alabama↗
PubMed1983

Induction of porcine uterine estrogen sulfotransferase activity by progesterone.

Studies have been carried out which were designed to examine the hormonal requirement for the appearance of estrogen sulfotransferase activity in porcine uteri. Mature, ovariectomized (OVX) gilts were housed for 3 weeks before being treated with various regimens of estradiol-17 beta (E2) and progesterone (P). Uteri were then removed, minced, incubated for 2 h with [3H] E2 (10(-8) M) and Na2 35SO4 (10(-4) M) and the labeled metabolic products were extracted and analyzed. Endometrial samples were also taken for the determination of E2 and P cytoplasmic and nuclear receptors (R). It was found that 4 daily injections of 250 micrograms of E2 was sufficient to bring plasma E2 concentrations to that representative of a normal estrous cycle (approx. 30 pg/ml) and to induce cytoplasmic PR to high levels (7000--19000 fmol/mg DNA). Estrogen sulfotransferase activity, which was negligible in OVX and E2-treated pigs, increased to near normal secretory levels (4 pmol product/h per 0.4 g tissue) only in pigs primed with E2 and subsequently treated with E2 and P (25--250 mg/day, 3 days). This treatment also brought about the translocation of PR to the nuclear compartment. The steroid alcohol sulfotransferase activity in these tissues decreased upon ovariectomy and remained unaffected by the hormone treatments. Endometria from treated and untreated pigs were cultured for a period up to 7 days. During this time E2 (10(-8) M) induced and/or maintained PR and P (10(-6) M) was shown to stimulate estrogen sulfurylation concomitant with the translocation of PR to the nucleus. These studies have demonstrated that, in OVX pigs and endometrial cultures, P stimulated uterine estrogen sulfotransferase activity to a level normally found in secretory uteri. In order for P to bring about elevated levels of estrogen sulfurylation it was necessary that the endometrium contain adequate concentrations of cytoplasmic PR (which required E2 priming of the system) and the P receptor complex must display nuclear translocation.

Animals↗
PubMed1983

Prophylaxis for infective endocarditis: antibiotic sensitivity of dental plaque.

The antibiotic sensitivity pattern of bacteria isolated from bacteraemia after dental extraction was compared with that of bacteria isolated from dental plaque samples from the same patient. The results supported the current practice of using penicillin and erythromycin empirically for prophylaxis. The prediction of the most appropriate antibiotic for prophylaxis using dental plaque samples was most accurate when the minimum inhibitory concentration (MIC) of plaque isolates were used. It appears that a predictive test using dental plaque may be of some value in patients with recent or long-term antibiotic therapy.

Adult↗
PubMed1981

Attitudes and perceptions of perinatal concepts during pregnancy in women from three cultures.

Interviewed Black-American, White-Anglo, and Cuban-Hispanic women (N = 126) during pregnancy and the puerperium in a longitudinal study of perinatal attitudes. Cultural differences emerged for the attitude toward Pregnancy, and differences across time emerged for the perception of activity of Unborn (Newborn) Baby. Such cultural and psychological factors need to be considered in the development of comprehensive prenatal care programs.

Attitude to Health↗