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Biomedical subjects

D Carr

Publications and source records attributed to D Carr.

At least 73 records · Page 4Linked to original sources
PubMed1994

Diagnostic pitfall; interpretation of CA 19-9 concentrations in the presence of hepatic dysfunction.

A 50 year old man is described with hepatic dysfunction and chronic pancreatitis in whom greatly increased concentrations of the pancreatic tumour marker CA 19-9 combined with an abnormal appearance at endoscopic retrograde cholangiopancreatography lead to the false suspicion of pancreatic carcinoma. CA 19-9 concentrations should be interpreted with caution in patients with intrinsic liver disease or biliary obstruction.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1994

HUBNET: Wide Area Network utilization of Local Area Network medical reference and communication resources.

The State University of New York at Buffalo School of Medicine and Biomedical Sciences and its associated teaching sites have developed and partially implemented a regional Wide Area Network (WAN) in Buffalo and Western New York. The school wishes to use this WAN to deliver reference and communication resources to students, residents and faculty. The richest pool of easy to use reference and communication resources are PC software programs that are intended for individual workstations or at best, client-server, Local Area Network (LAN) implementation. HUBNET (Hospitals and University at Buffalo Library Resource Network), a project of the School of Medicine and the Library Consortium of Health Institutions in Buffalo offers integrated presentation of many such LAN resources over this regional WAN. The system crosses many institutional boundaries and reaches physically remote sites in a complex mix of information systems environments with few issues related to performance. The system design provides a level of ease of use that has brought many new users into active computer use while addressing integration into diverse information systems settings and networking environments.

Computer Communication Networks↗
PubMed1993

Aldolase-tubulin interactions: removal of tubulin C-terminals impairs interactions.

Aldolase copelleted with taxol stabilized microtubules with a Bmax = 0.74 moles of aldolase per mole of tubulin dimer. Removal of the carboxy terminals from microtubules with limited subtilisin digestion, decreased binding to 0.16 moles of aldolase per mole of tubulin dimer. Aldolase inhibited subtilisin cleavage of the C-terminals while triose phosphate isomerase, an enzyme that does not interact with microtubules, did not affect subtilisin activity. These data indicate that the carboxy terminals are involved in tubulin-aldolase interactions.

Animals↗
PubMed1992

Factors affecting the separation and loading capacity of proteins in preparative gradient elution high-performance liquid chromatography.

The optimum conditions for the purification of proteins by gradient elution in reversed-phase liquid chromatography were studied, with emphasis on the column length. Because of the strong dependence of the retention of proteins on the mobile phase composition, very short columns can be used successfully to perform analytical separations. A similar conclusion is extended to preparative separations. Columns with different lengths and diameters were used. The dependence of the loading capacity for touching band separation on the column length, diameter and volume was studied, in addition to the regeneration time between successive runs, the starting mobile phase composition and the necessary column efficiency.

Animals↗
PubMed1992

Forced splitting of human sleep in free-running rhythms.

The assumption of polyphasic sleep/wake regulation is based on the occurrence of nap-sleep at specific phase positions in the circadian cycle. Further support would be the split of the normal long major sleep episode into shorter components. Evidence for this hypothesis comes from the discovery of bimodal distribution in sleep duration. An experimental approach to test this hypothesis has been carried out by restricting sleep duration in free-running rhythms. The outcome was a biphasic distribution of sleep within a circadian cycle with sections of dissociation and synchronization of the two sleep blocks. The results show similarities with 'splitting', a phenomenon which has been found in animal studies. The relatively short duration of the different sections as well as the asymmetric distribution of the two sleep blocks in the circadian cycle leads to the assumption of a splitting of the major sleep episode and not of the circadian rhythm. Sleep split into two, relatively short sleep episodes of comparable duration contrasts with napping, which is characterized by an extra sleep episode in addition to the long major sleep.

Journal Article↗
PubMed1992

The effect of age on driving skills.

OBJECTIVE: To assess the effect of age on driving skills independent of the limitations related to disease or dementia. DESIGN: Prospective comparison of driving skills across three age groups. SETTING: A university-based research study of student and university-affiliated volunteers. PARTICIPANTS: Healthy elderly (age 65+), teen-age (age 18-19), and young adult drivers (age 25-35). Twenty subjects in each age group were recruited after meeting entry criteria for the study. MAIN OUTCOME MEASURES: Total error count and score on the Miller Road Test, a standardized road test developed by the Division of Bus and Traffic Safety in North Carolina. RESULTS: The elderly were found to have fewer errors than either of the two younger groups of drivers (P = 0.0013). Specific driving skills were judged to be either superior or unchanged in the elderly subjects in comparison to their younger counterparts. CONCLUSIONS: Road test skills appear to be well preserved in the healthy elderly population. More road test studies are needed on elderly individuals with mental and physical impairments to determine if road tests can play a role in identifying the driver at high risk for a crash.

Adolescent↗
PubMed1992

The effects of time delays on a telepathology user interface.

Telepathology enables a pathologist to examine physically distant tissue samples by microscope operation over a communication link. Communication links can impose time delays which cause difficulties in controlling the remote device. Such difficulties were found in a microscope teleoperation system. Since the user interface is critical to pathologist's acceptance of telepathology, we redesigned the user interface for this system, built two different versions (a keypad whose movement commands operated by specifying a start command followed by a stop command and a trackball interface whose movement commands were incremental and directly proportional to the rotation of the trackball). We then conducted a pilot study to determine the effect of time delays on the new user interfaces. In our experiment, the keypad was the faster interface when the time delay is short. There was no evidence to favor either the keypad or trackball when the time delay was longer. Inexperienced participants benefitted by allowing them to move long distances over the microscope slide by dragging the field-of-view indicator on the touchscreen control panel. The experiment suggests that changes could be made to the trackball interface which would improve its performance.

Costs and Cost Analysis↗
PubMed1992

Monoamines in the brain cerebrospinal fluid of facial pain patients.

The purpose of the study was to assay monoamines in cerebrospinal fluid (CSF) obtained from the trigeminal cistern of 64 patients with intractable facial pain. The CSF was analyzed for homovanillic acid (HVA), 5-hydroxyindoleacetic acid (5-HIAA), and 3-methoxy-4-hydroxyphenylglycol (MHPG), end-product markers of activity for the dopamine, serotonin, and norepinephrine systems, respectively. HVA averaged 121 ng/mL in these facial pain patients, compared to 150 to 550 ng/mL in 10 studies of ventricular brain CSF in assorted psychiatric and pain patients. 5-HIAA averaged 29 to ng/mL in our facial pain patients compared to 60 to 120 ng/mL in nine studies of ventricular brain CSF in assorted psychiatric and neurological patients. Trigeminal cistern CSF MHPG averaged 9 ng/mL, similar to the range of 13 studies of lumbar CSF of assorted psychiatric and pain diagnoses. These results indicate that (1) the electrochemical detection method provides a unique way of accurately measuring nanogram concentrations of multiple monoamines in a little as 0.25 mL of CSF; (2) trigeminal cistern and posterior fossa brain CSF monoamine metabolites reflect a different profile of dopaminergic and serotonergic functioning in these facial pain patients from that previously reported with lumbar CSF measurements of other patients; and (3) trigeminal sensory ganglion or brain dopamine and serotonin systems may be concomitantly dysfunctional in intractable facial pain.

Analysis of Variance↗
PubMed1991

Non-Hodgkin's lymphomas in patients with human immunodeficiency virus infection. Presence of Epstein-Barr virus by in situ hybridization, clinical presentation, and follow-up.

The authors studied all patients with serologic evidence of human immunodeficiency virus (HIV) infection and malignant non-Hodgkin's lymphoma (NHL) that presented at a single hospital from 1982 to 1989. Sixteen patients were identified, all white homosexual men with a mean age of 38.2 years. Lymphoma was the initial presentation of HIV infection in 37.5%. Sixty-two percent of the cases had a high-grade NHL, 31% had intermediate-grade, and 6% (one patient) had a low-grade lymphoplasmacytoid lymphoma. Extranodal involvement was present in 43.7%, with the gastrointestinal tract and liver being the most common sites. Actuarial survival was increased by treatment with methotrexate, doxorubicin, cyclophosphamide, vincristine, prednisone, and bleomycin (MACOP-B). Colorimetric in situ hybridization identified Epstein-Barr virus (EBV) in nine of the 14 cases hybridized. A statistically significant association of EBV with diffuse small noncleaved type (i.e., Burkitt's-like) (six of six) compared with other morphologic types (three of eight) was found (P = 0.025).

Adult↗
PubMed1991

The impact of a health education course on maternal knowledge: a comparative study in a low socioeconomic rural region.

A comprehensive health education course was designed for mothers in West Bank villages, a relatively low socioeconomic population. The course focused on nutrition, hygiene, child development, and first aid. It was taught by specially trained local instructors in small classes characterized by an individualized teaching method. To evaluate the contribution of the course, the level of knowledge in topics taught in the course was tested. The test was personally administered by trained interviewers to 241 course participants and to a comparison group of 284 mothers who had not participated. As expected, participants demonstrated higher level of knowledge than nonparticipants, regardless of the time since having taken the course. The course seems to have contributed to all participants, but mostly to women of lower education. In a multiple linear regression the two most significant predictors of knowledge were course participation and level of maternal formal education.

Educational Status↗
PubMed1991

Trigeminal facial pain: a model of peptides and monoamines in intracerebral cerebrospinal fluid.

A biochemical model of chronic trigeminal facial pain with elevated substance P (SP) and co-dysfunctional dopamine (DA), norepinephrine (NE) and purinergic systems is proposed. The serotonergic system is hypoactive as judged by low 5 hydroxyindoleacetic acid (5HIM). In distinction, intracerebral opioids may not be dysfunctional in facial pain as measured by normal levels of beta endorphin (BE). The neuropeptides somatostatin (SOM), cholecystokinin (CCK), met and leu-enkephalin (MENK, LENK) have very small picogram concentrations in these pain patients, but no definite conclusion can be reached on their role in trigeminal pain, alone or with monoamines, because of the small numbers, both sample size and concentrations. Interpretive obstacles to such human neurochemical studies suggest that future work might move to human clinical trials comodulating SP down, inhibitory peptides (SOM, CCK) up, and enhancing monoamine systems.

Biogenic Monoamines↗
PubMed1990

Characteristics of an elderly driving population referred to a geriatric assessment center.

A retrospective, case-control study was performed to determine the characteristics of elderly drivers referred to an outpatient geriatric assessment center. It was hypothesized that the driving population was operating at a higher cognitive and functional level than nondrivers. One hundred eighty-two subjects meeting the entry criteria were studied. Twenty-three percent of the subjects were driving at the time of their assessment. Compared to nondrivers, drivers were younger (P = .0001), were more likely to be male (P = .003), scored higher on a mental status examination (P = .0001), and were more independent in Physical and Instrumental Activities of Daily Living (P less than .0001). Despite these findings, the mean Folstein Mini-Mental score for drivers (23.7) was below normal; 40% of drivers were diagnosed as having Alzheimer's dementia at the time of their evaluation, and over 26% of the drivers needed help with either dressing or bathing. The frequency of impaired elderly drivers in this referral setting was high. The authors conclude that conditions that affect the driving task are common in geriatric assessment centers. Prospective studies of elderly drivers are needed to answer the difficult question of who among the elderly should drive.

Activities of Daily Living↗
PubMed1990

Infant feeding practices: an evaluation of the impact of a health education course.

We assessed the impact of a health education course on infant feeding practices in the West Bank territories by comparing mothers who had attended the course (n = 102) with mothers not exposed to the course (n = 133). After adjustment for child's age, maternal age and education, parity, and birth site, course participants were more likely than non-participants to breastfeed, as well as to start supplementation by semi-solid foods at the recommended time.

Breast Feeding↗
PubMed1990

Effect of single setting versus multiple setting training on learning to shop in a department store.

The effects of single versus multiple setting training on the generalization of shopping skills to untrained department stores were analyzed. One group received training in a single department store and the other, in three different stores. Measures were taken on operational behaviors, social behaviors, number of settings in which criterion performance was achieved, and number of sessions required to achieve criterion within the training settings. No differences between groups were found as a result of training condition. We concluded that for some individuals with mental retardation, training in either single or multiple settings may be sufficient for generalization.

Adolescent↗
PubMed1988

Fine adjustment of thyroxine replacement dosage: comparison of the thyrotrophin releasing hormone test using a sensitive thyrotrophin assay with measurement of free thyroid hormones and clinical assessment.

Thyroxine replacement therapy for 21 adult patients with primary hypothyroidism was adjusted to the dosage at which each patient had a normal thyrotrophin (TSH) response to thyrotrophin releasing hormone (TRH). Clinical assessment and measurement of TSH (by sensitive immunoradiometric assay), free thyroxine (FT4) and free tri-iodothyronine (FT3) were made at this dosage and at higher and lower doses of thyroxine. Clinical observations, FT3 and FT4 assays were relatively insensitive to small alterations of thyroxine dosage, in contrast to which basal TSH measurements correlated well with TRH responsiveness and were sensitive to fine adjustments of thyroxine dosage.

Adult↗