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Biomedical subjects

D Jacobs

Publications and source records attributed to D Jacobs.

At least 109 records · Page 6Linked to original sources
PubMed1991

Maturational increase in mouse brain creatine kinase reaction rates shown by phosphorus magnetic resonance.

In-vivo phosphorus fluxes in the reaction catalyzed by creatine kinase (CK) were measured in brains of mice from 3 to 40 days of age using high-field (8.45 T) phosphorus magnetic resonance and the saturation transfer technique. This technique gives the ratio of chemical flux to reactant concentration directly and allows the calculation of pseudo-rate constants for the forward direction from PC to ATP (kf) and for the reverse direction (kr). The spin-lattice relaxation times (T1) for phosphocreatine (PC) and for the nucleoside triphosphate (NTP) nuclei, estimated by the progressive saturation technique, did not change during this age period. The PC concentration doubled relative to the NTP concentration over the first month of life. The kf and the flux of phosphorus nuclei in the forward direction increased 2- to 3-fold in the very narrow time period from 12 to 15 days of age. Brain phosphorus flux from PC to ATP thus increased 4- to 6-fold in the first month of life. An increase at least that large occurred in the reverse direction, but the kr could not be measured consistently in the younger animals using the saturation transfer technique. Phosphorus fluxes were equal in the forward and reverse directions in the mature brain. The capacity to increase rates of glycolysis and tissue respiration in response to increased energy demand appears in the same narrow age period as the increase in CK-catalyzed reaction rates in the developing rodent brain. We propose that these coincident changes in brain energy metabolism reflect the maturation of mechanisms for coupling cell energy production to rapid changes in energy requirements.

Adenosine Triphosphate↗
PubMed1991

A case of granulomatous hepatitis after intravesical bacillus Calmette-Guerin administration.

A 61-year-old man received intravesical bacillus Calmette-Guerin (BCG) as treatment for superficial bladder carcinoma. High spiking relapsing fevers began 39 days after the initial treatment. A liver biopsy revealed noncaseating granuloma. Deoxyribonucleic acid hybridization of the bone marrow was positive for Mycobacterium tuberculosis complex. Pressure exerted to instill the BCG may have favored dissemination.

Administration, Intravesical↗
PubMed1991

The CARDIA dietary history: development, implementation, and evaluation.

To meet the objectives for dietary assessment in the Coronary Artery Risk Development in Young Adults (CARDIA) prospective study, we developed a dietary history to provide accurate and reliable quantitative data on habitual individual nutrient intakes at baseline. The CARDIA dietary history was an interviewer-administered method that included a short questionnaire regarding general dietary practices followed by a comprehensive food frequency questionnaire about typical intake of foods using the previous month as a reference for recall. For each broad category of foods, participants were questioned in detail about specific foods only if they indicated that they consumed foods from that category. Follow-up questions for selected foods concerned serving size, frequency of consumption, and common additions to these foods. Provision was made for reporting foods not found in the food frequency list. The interview took approximately 45 minutes. Cue cards prompted responses and plastic food models assisted in estimating usual amounts consumed. A precoded format standardized coding for reported items and established the detail needed for recall during the interview. Baseline nutrient analyses from the CARDIA dietary history provided estimates that agreed reasonably well with expected caloric intake for body mass index according to the age- and sex-specific Recommended Dietary Allowances, but were higher than those reported from 24-hour recalls for comparable age, sex, and race groups in the second National Health and Nutrition Examination Survey. The CARDIA dietary history is a comprehensive assessment tool that can provide a dietitian with detailed information regarding habitual eating patterns and nutrient intakes among adults.

Adult↗
PubMed1990

Voluntary HIV antibody testing among STD clinic patients: a pilot study.

A pilot study was conducted with the aim of measuring the acceptability of voluntary testing for human immunodeficiency virus (HIV) antibody among patients attending sexually transmissible disease (STD) clinics. Three STD clinics, two public and one private, participated in the study which was conducted over a three-month period beginning in November 1988. For each patient attending the clinics, sex, date of birth, HIV transmission category and previous HIV test result were recorded. Patients who did not request the HIV antibody test were offered testing. Of the 2356 patients who were included in the analyses, 784 (34%) requested testing. For almost all patients (97%) who requested testing, a serum sample was collected and testing completed. Approximately half (55%) of those patients who were offered the test accepted testing. Overall, 70% of patients completed HIV antibody testing. Of the major transmission categories, the acceptance rate for those offered the test was lowest among homosexual men (45%), who also had the highest rate of HIV antibody seropositivity (11%) among those tested. Of patients who reported themselves to be HIV antibody seronegative prior to the pilot study, 78% were retested during the study and seven had a positive test for HIV antibody. We conclude that voluntary HIV antibody testing is acceptable in both public and private STD clinic settings, although a substantial amount of additional resources would need to be allocated to counselling if voluntary testing is to be introduced on a routine basis.

Acquired Immunodeficiency Syndrome↗
PubMed1990

Intra-abdominal abscess after blunt abdominal trauma.

The relationship between blunt abdominal trauma and intra-abdominal abscess (IAA) is discussed infrequently; therefore we conducted a retrospective review of 4050 multiple blunt trauma admissions from January 1986 to July 1988. Of 325 patients who had a laparotomy for blunt abdominal trauma, we identified 15 (4.6%) who had 40 IAAs. The most common intra-abdominal injuries involved the spleen and liver. Splenectomy increased the risk for IAA in contrast to splenic salvage. Blunt injuries to the kidney and pancreas, when occurring in multiple trauma patients, carried a significant risk of IAA. Associated multiple extra-abdominal injuries and high transfusion requirements increased the risk for IAA formation. Most of the IAAs were located in the upper quadrants. There was a 46% incidence of multiple IAA, which in turn had an 80% chance of recurrence after initial drainage. Enterobacter species played an important role in the formation of IAA in our trauma patients. Three patients (20%) died. Poor prognostic indicators included a high injury severity score, high transfusion requirements, the presence of pelvic fracture, positive blood cultures, multiple organisms per abscess, and multiple-organ system failure.

Abdominal Injuries↗
PubMed1990

Differential expression of Hox 3.1 protein in subregions of the embryonic and adult spinal cord.

Synthetic oligopeptides derived from the predicted Hox 3.1 protein coding sequence were used for the production of antibodies (anti-aa2) that specifically recognize Hox 3.1 protein in tissue sections. These antibodies were applied in immunohistochemical studies to monitor the expression of Hox 3.1 protein within the central nervous system (CNS) of embryonic and adult mice. We demonstrate congruency between the distinct Hox 3.1 RNA and protein expression patterns in the developing spinal cord by direct comparison of in situ hybridization and immunohistochemical staining in frozen sagittal sections from embryos of 12.5 days of gestation. A distinct pattern of spatially restricted expression of Hox 3.1 protein within the spinal cord was first detected at around 10.5 days of embryonic development. Within certain anteroposterior limits the geometries of this expression pattern change drastically during subsequent embryonic stages, concomitant with important cytoarchitectural changes in the developing spinal cord. Analyses on subcellular levels indicate predominant accumulation of Hox 3.1 protein within nuclei of neuronal cells. In addition to the nuclear localization in subsets of embryonic cells, persistent accumulation of Hox 3.1 protein was shown in nuclei of fully differentiated and mature neuronal cells of the adult CNS.

Animals↗
PubMed1990

Comparison of chromosome analysis to DNA content by flow cytometry for pediatric tumors.

Chromosome analyses in a series of 50 pediatric tumor samples showed abnormal chromosome number, ranging from hypodiploid to tetraploid. Aliquots of the same solid tumor samples were analyzed by flow cytometry (FCM). Material from spontaneous abortions and 12 tumor samples with normal chromosomes were also compared in a control series of 83 samples. Tumors or abortuses with 44-48 chromosomes could not be differentiated from material with normal diploid complement by FCM. However, greater than or equal to 3-4 extra chromosomes produced detectable differences in mean DNA index. Triploidy and tetraploidy were readily identified by FCM. It is concluded that FCM could identify an important group of hyperdiploid pediatric tumors, as well as 3N and 4N tumor complements.

Child↗
PubMed1990

Intrusion errors in the figural memory of patients with Alzheimer's and Huntington's disease.

The tendency of patients with dementia of the Alzheimer type (DAT) and Huntington's disease (HD) to produce prior-item intrusion errors on a figural memory task was assessed. Patients' and elderly control subjects' immediate recall of figures from the Visual Reproduction Test (VRT) of the Wechsler Memory Scale (WMS) was scored for the presence of prior-figure intrusion errors (i.e., characteristics unique to one figure included in the reproduction of a subsequent figure). Results indicate that both patient groups produced more prior-figure intrusion errors than did the NC group, and that DAT patients made significantly more intrusion errors in their reproductions than did HD patients matched for overall severity of dementia. These data suggest that prior-item intrusion errors are evident on figural as well as on verbal memory tasks and that DAT patients are more likely to produce such errors than are equally demented patients with a "subcortical" dementia.

Journal Article↗
PubMed1989

Fe2+ binding to apo and holo mammalian ferritin.

The binding of Fe2+ to both apo and holo mammalian ferritin has been investigated under anaerobic conditions as a function of pH. In the pH range 6.0-7.5, 8.0 +/- 0.5 Fe2+ ions bind to each apoferritin molecule, but above pH 7.5, a pH-dependent Fe2+ binding profile is observed with up to 80 Fe2+ ions binding at pH 10.0. This Fe2+ binding is reversible and is accompanied by up to two H+ being released per Fe2+ bound at pH 10.0. The Fe2+ binding to apoferritin probably occurs in the 3-fold channels. A much larger and more complex pH-dependent Fe2+ binding stoichiometry was observed for holoferritin with up to 300 Fe2+ ions binding at pH 10.0. This pH-dependent Fe2+ binding was interpreted as Fe2+ interaction at the FeOOH mineral surface with displacement of H+ from -OH or phosphate surface groups by the incoming Fe2+ ions. Mossbauer spectroscopic measurements using 57Fe-labeled Fe2+ under anaerobic conditions showed that 57Fe2+ binding to holoferritin was accompanied by electron transfer to the core, yielding 57Fe3+, presumably bound to the mineral surface. Removal of added iron by Fe2+-specific chelating agents yielded 57Fe2+, demonstrating the reversibility of this electron-transfer process. The Fe2+ bound to apo- and holoferritin is readily converted to Fe3+ by exposure to O2 and strongly retained by the respective ferritin species.

Animals↗
PubMed1989

Twenty-four-hour sleep-wake patterns in a nursing home population.

Sleep-activity patterns were objectively recorded over a 24-hr period in 19 elderly nursing home residents. On average, both sleep and wake times were observed during every hour of the 24 recorded hours; however, the sleep pattern of the residents was fragmented so that they rarely experienced even a single hour of consolidated time spent sleeping. It is hypothesized that several independent factors, including compensation for lost sleep, increased total time in bed, weakening of social constraints, and deterioration of the circadian sleep-wake rhythm, are interacting to produce this increase in sleep fragmentation.

Activities of Daily Living↗
PubMed1989

The neuroendocrine response to oral dextroamphetamine in normal subjects.

In 24 male subjects oral dextroamphetamine 20 mg caused a statistically significant rise in cortisol, prolactin, TSH, FSH, and LH compared to placebo. Dextroamphetamine caused a short-lived rise in growth hormone and attenuated the later rise which occurred after placebo. The findings are discussed in the light of previous reports of the neuroendocrine response to dextroamphetamine in normal subjects and in psychiatric patients.

Adolescent↗
PubMed1989

The role of dopaminergic and noradrenergic receptors in human TSH and LH release.

The present study was undertaken to evaluate the relative roles of noradrenergic (NA) and dopaminergic (DA) neurotransmission in the control of thyrotropin (TSH) and luteinizing hormone (LH) release. Oral dextroamphetamine 20 mg caused a rise in the serum levels of TSH and LH in 24 healthy male volunteer subjects. The increase in TSH secretion was augmented by prior treatment with pimozide and reduced by thymoxamine. Conversely the LH response to destroamphetamine was reduced by pimozide and possibly accentuated by thymoxamine. The results confirm an inhibitory role for DA receptors in the control of TSH release and indicate that NA receptors may exert a facilitatory role. The converse would appear to be the case with LH, with DA being facilitatory and NA possibly inhibitory.

Adult↗
PubMed1989

Differentiating Alzheimer's disease from Huntington's disease with the Wechsler Memory Scale-Revised.

The WMS-R represents a significant improvement over the original version of the WMS. Patterns of performance on the five WMS-R indices successfully differentiated patients with a "cortical" (that is, DAT) from patients with a "subcortical" (that is, HD) dementia. The differences between ACI and GMI also indicated that DAT patients' attention and concentration were better preserved than those of equally demented HD patients. Analyses of the differences between GMI and DMI indicated that rapid forgetting was more apparent for DAT than for HD patients in the early stages of these disorders. When savings scores for the Logical Memory and Visual Reproduction tests were used to examine retention over a 30-minute period, both mildly and moderately demented DAT patients demonstrated more rapid forgetting than did HD patients with similar levels of cognitive decline. Discriminant analyses performed with these indices of forgetting showed 95 per cent accurate classification of DAT and elderly controls, and 79 per cent correct classification of DAT and HD patients. Assessment of the patients' tendencies to make prior-item intrusion errors on the Visual Reproduction tests of the WMS and WMS-R yielded significant differences between patient groups and the two versions of the test. Patients with DAT made significantly more prior-figure intrusion errors than did HD patients on both versions of the VRT, but the original WMS form of this figural memory test was more likely to elicit such errors than was the revised version. Despite many improvements in the revised scale, a number of limitations still exist including standardization and a lack of norms for elderly individuals, as well as failures to include tests of verbal recognition and adequate measures of nonverbal memory.

Alzheimer Disease↗