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Biomedical subjects

T Patterson

Publications and source records attributed to T Patterson.

At least 37 records · Page 2Linked to original sources

Solubilized HLA class I antigen enzyme-linked immunoassay to identify HLA-typing reagents.

The objective of this study was to evaluate the use of sHLA in a solid-phase EIA as a rapid and sensitive way to identify potential IgG HLA class-I-typing reagents. To evaluate the efficacy of the sHLA EIA, we used the assay to screen 259 HLA-A, -B, and -C antisera that our laboratory had procured using the standard NIH LCA. A positive result obtained by the sHLA EIA, which was defined as an EIA ratio of 3 SD above the mean of 91 anti-HLA-negative sera, revealed that 91% (79 of 87) of the A-locus-typing reagents were positive, 96% (150 of 156) of the B-locus antisera were positive, and only 75% (12 of 16) of the C-locus reagents were positive. The typing reagents that were negative by EIA (n = 18) fell into two categories. First, 38% (7 of 18) were negative by sHLA EIA, as they were IgM-typing reagents (NIH LCA reactivity ameliorated by DTT). The second group of the 11 remaining typing reagents had a mean EIA ratio of 1.0 +/- 0.246 (mean +/- 1 SD), which was significantly (P < 0.001) higher than the mean of the 91 negative controls that were used to establish the negative cutoff. The overall sensitivity of the sHLA EIA to detect HLA class-I-directed IgG was 97.2%.

Female

Effects of marijuana history on the subjective, psychomotor, and reinforcing effects of nitrous oxide in humans.

An experiment using marijuana users and non-users was conducted to assess whether the reinforcing, subjective, or psychomotor effects of nitrous oxide were influenced by a subject's drug history. Subjects in the first four sessions sampled 40% nitrous oxide in oxygen and 100% oxygen (placebo), and then over the next three sessions, chose which agent they wished to inhale. Choice distributions between the two groups did not differ significantly, and nitrous oxide choice rates were less than 50% in both groups. However, a history of marijuana use appeared to intensify some of the subjective effects induced by nitrous oxide inhalation.

Administration, Inhalation

Outbreak of SRSV gastroenteritis at an international conference traced to food handled by a post-symptomatic caterer.

In an outbreak of small round structured virus (SRSV) gastroenteritis at an international AIDS conference 67 people were ill with diarrhoea or vomiting, one requiring admission to hospital. Epidemiological investigations demonstrated that the vehicle of infection was food prepared by a foodhandler who was recovering from a mild gastrointestinal illness. The food most strongly associated with illness, coronation chicken, was prepared by the food handler on the second day after symptoms ceased. The investigation confirms the view that foodhandlers may contaminate food with SRSVs after cessation of symptoms and should remain off work until at least 48 h after recovery.

Adolescent

OKT3 first-dose reaction: association with T cell subsets and cytokine release.

Use of the monoclonal antibody OKT3 to prevent or treat allograft rejection has become commonplace. Its administration is often complicated by serious side effects, usually occurring within one to two hours after OKT3 is given, and is termed first-dose reaction. The mechanism underlying these signs and symptoms is poorly defined, but may be related to cytokine release. Twenty-three kidney or kidney/pancreas transplant recipients received OKT3 as treatment of acute rejection. Signs and symptoms occurring after the first dose were observed and quantitated prospectively, and a reaction score was calculated. Blood was drawn immediately before, and at 2 and 24 hours after the first dose of OKT3 for determination of interleukin-2 (IL2), interferon-gamma (IFN gamma), and tumor necrosis factor-alpha (TNF alpha) levels, and flow cytometric analysis of T cell subsets. Two groups were defined based on severity of first-dose reaction. Group 1 patients (N = 11) had very mild reactions (reaction score less than or equal to 3); Group 2 patients (N = 12) had more severe reactions (score greater than or equal to 5). All patients demonstrated a significant rise in serum TNF alpha from baseline to two hours after OKT3 (9 +/- 3 pg/ml to 378 +/- 54 pg/ml, P less than 0.0001), and there was significant correlation between reaction scores and two-hour TNF alpha levels (P = 0.005). Group 2 patients had higher TNF alpha levels at two hours than did Group 1 patients (484 +/- 75 pg/ml vs. 263 +/- 62 pg/ml, P = 0.04). Levels of IL2 and IFN gamma were not elevated at any sampling time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Neuropeptide Y and natural killer cell activity: findings in depression and Alzheimer caregiver stress.

A reduction in immune function has been found in patients with a major depressive disorder and in persons undergoing severe life stress. This study investigated the association between increased sympathetic nervous system activity and reduced natural killer (NK) cytotoxicity in depression and Alzheimer caregiver stress. NK activity and plasma concentrations of epinephrine, norepinephrine, and neuropeptide Y were measured in depressed patients (n = 19) and age- and gender-matched controls (n = 19), and in Alzheimer spousal caregivers (n = 48) and matched noncaregiver controls (n = 17). Plasma levels of neuropeptide Y, but not circulating basal levels of catecholamines, were significantly (P less than 0.01) elevated in the depressed patients and in the caregivers compared with respective controls. NK activity was significantly (P less than 0.001) lower in the depressed patients than in their controls, but not different between the caregivers and the noncaregiver controls. Circulating concentrations of neuropeptide Y, but not catecholamines, were inversely correlated (r = -0.31, P less than 0.001) with NK activity. In addition, multiple regression analyses demonstrated that the significant (P less than 0.01) association between neuropeptide Y and natural cytotoxicity was independent of the relative contribution of age and basal and dynamic levels of epinephrine and norepinephrine. These findings suggest that increased sympathetic nervous system activity and the release of neuropeptide Y may be associated with the modulation of NK cytotoxicity.

Alzheimer Disease

Reduction of immune function in life stress and depression.

Reduced cell-mediated immune function has been found in depressed patients and in distressed persons undergoing threatening life events. The present study examines the interaction between severe life stress and major depression to produce immune alterations in 36 matched pairs of hospitalized depressed patients and nondepressed controls. Both major depressive disorder and the presence of threatening life events in control subjects are independently associated with a 50% reduction of natural killer (NK) cytotoxicity. A decrease in natural cytotoxicity is significantly associated with depressive symptoms but not with age, alcohol consumption, or tobacco smoking. These findings of altered immunity provide further evidence that the physiological responses in chronic stress parallel those found in the syndrome of depression.

Adult

Cloning and expression of a collagen-analog-encoding synthetic gene in Escherichia coli.

A family of totally synthetic genes coding for multiple tandem repeats of the amino acid sequence (Gly-Pro-Pro) has been prepared and inserted into the ClaI cloning site of the expression vector pJL6. A representative recombinant plasmid, pAC1, with an insert of about 340 bp was established in an Escherichia coli strain bearing a defective lambda prophage, to study expression of the CII-collagen analog fusion protein produced from pAC1 upon heat induction. Authentic fusion protein production was demonstrated by nucleotide sequencing, Northern-blot analysis, and in vivo synthesis. Conversion of a wild-type rpoH allele to the rpoH165 mutation was shown to suppress proteolysis of the unstable fusion protein.

Amino Acid Sequence

Survey of attitudes to testing for human immunodeficiency virus infection in antenatal clinics in West Glamorgan.

A total of 1023 women attending hospital antenatal clinics in West Glamorgan was surveyed by means of a self-administered questionnaire, to determine their attitudes to HIV testing in pregnancy. The response rate was 98%. Of the responders, 94% had no objection to their antenatal blood specimen being tested for HIV infection. Of the non-objectors, 55% wished their permission to be asked first, and 92% wished to be informed of the result, i.e. they wished for named testing. With regard to knowledge of other tests for infectious diseases performed on antenatal blood specimens, only 1.5% had totally correct knowledge, and only one in three knew that their blood was tested for syphilis. The implications of anonymous and named HIV testing are discussed, together with estimates of prevalence of HIV infection in women attending antenatal clinics, the rate of vertical transmission, and the prognosis for an infected baby.

AIDS Serodiagnosis

Outpatient methadone programme for pregnant heroin using women.

A prospective study of pregnant narcotic users who attended the antenatal clinic at Westmead Hospital was undertaken to determine the practicality and safety of an outpatient methadone programme for these women. Forty-six women were commenced and managed on a methadone maintenance programme based at the Drug and Alcohol Clinic at Westmead Hospital (GROUP I), 12 women were maintained on long-term methadone therapy by outside prescribers (GROUP II), 12 women not on methadone continued to use heroin through the pregnancy (GROUP III), 14 women used heroin intermittently (GROUP IV). These were compared with a group of 52 women who were non-drug using (GROUP V). Women on the hospital based methadone programme had an earlier first antenatal clinic visit (p less than 0.001) than those women on outside methadone programmes or on heroin and had a longer pregnancy (p less than 0.001) than those women on heroin. The birth-weights on babies delivered to women on the Westmead Methadone Programme were significantly higher than those on babies born to women using heroin (p less than 0.05). A disappointing aspect of the study was a lower number of antenatal clinic visits (p less than 0.001) for all narcotic using women when compared with the comparison group. The outcome of the Westmead Methadone Programme women showed that better maternal and neonatal outcome followed entry into a hospital monitored methadone programme with attendant antenatal care.

Adult

Severely threatening events and marked life difficulties preceding onset or exacerbation of multiple sclerosis.

Information was obtained on stressful life circumstances, using the Life Events and Difficulties Schedule (LEDS) from 39 patients with early multiple sclerosis and 40 matched nonpatient volunteers. The proportion of multiple sclerosis patients who experienced marked life adversity in the year prior to onset of symptoms was significantly higher than for nonpatients in the year before interview (77% vs. 35%). The excess in marked life stress was most evident in the 6 months before onset. Such stressors might explain the timing of symptom exacerbation for some patients with multiple sclerosis, perhaps by perturbing an already unstable neuroimmunological system.

Adaptation, Psychological

Mortality rates of patients admitted to a psychogeriatric assessment unit.

Admission of elderly people to a geriatric hospital may carry an increased risk of death. In this study 355 admissions of 243 elderly persons with dementia to a purpose built psychogeriatric unit were studied and the mortality rate found to be 8.2%, which is less than that reported elsewhere. Admission for the purpose of respite (holiday) relief is a safe procedure and should not be discouraged.

Aged

Indwelling umbilical arterial catheter: a preferred sampling site for blood culture.

Indwelling umbilical arterial catheter was evaluated prospectively as an alternative site for blood culture sampling. In 282 infants, 318 paired blood cultures were obtained from the peripheral vein and from the indwelling umbilical arterial line. Duration of umbilical catheter placement ranged from 0.5 to 196 hours; in 17% of the infants, catheters were in place for between 24 and 196 hours. In 13 blood culture pairs the same pathogens were found and had been obtained from the peripheral vein and the umbilical arterial line. Two pairs were positive for discrepant organisms. A total of 11 pairs were positive in one site only, with five positive from peripheral vein only and the other six from the umbilical arterial catheter. However, most of these single-site positive blood cultures were apparently true positives based on supporting laboratory data for infection. Contamination rates were 1.3% and 0.9% for peripheral vein and umbilical arterial catheter blood cultures, respectively. Thus, in sick neonates, the indwelling umbilical arterial line was an alternative and perhaps a preferred site for blood culture sampling.

Blood

Life events do not predict symptoms: symptoms predict symptoms.

The effects of life events and previous symptoms on current symptom levels were examined in a model using data from a 3-year prospective study. Male psychiatric patients and nonpatients reported on life events and symptoms every 2 months on 18 occasions. Logistic regression analysis of these data revealed little dependence of psychiatric symptoms on preceding life events as measured by the Holmes and Rahe Schedule of Recent Experiences (SRE). The best predictor of the current symptom level was the level of previous symptoms. It is concluded that efforts to relate changes in the social environment to health must first consider the possible contribution of the antecedent symptom level to the variability in health outcome.

Adult

Assessing knowledge of cardiovascular health-related diet and exercise behaviors in Anglo- and Mexican-Americans.

This article describes the Adult and Child Behavior Knowledge Scales that were used as part of the San Diego Family Health Project to measure knowledge of health behaviors related to cardiovascular diseases in two ethnic groups: Anglo- and Mexican-Americans. The psychometric characteristics of these scales indicate acceptable reliabilities for assessing knowledge of dietary sodium, dietary fat, and exercise among both adults and children and differ from other health knowledge scales in that they focus on "behavioral capability" rather than on the link between behavior and disease. It is believed that the type of information measured by our scales is more closely related to behavior changes sought in contemporary cardiovascular disease prevention trials. Results of ANOVA used to test differences in knowledge by ethnicity and sex indicate strong main effects for ethnicity among both children and adults. However, sex was not consistently related to knowledge, except for the general tendency of males to be more knowledgeable about exercise. Step-wise and simultaneous-entry multiple regression were used to test a subset of variables, including sex, education, self-efficacy, acculturation (for Mexican-Americans), and parental health knowledge (for children) as determinants of health knowledge. Education was the strongest predictor for Anglo-American adults, and acculturation level was the strongest for Mexican-American adults. Among children, the only statistically significant variable was parental acculturation level for Mexican-Americans. The scales were found to be useful in measuring differences in knowledge across cultural/linguistic groups and to clearly identify marginally acculturated Mexican-Americans as being least aware of health-behavior knowledge. Implications are discussed.

Acculturation

Topographic evoked potentials during backward masking in schizophrenics, patient controls and normal controls.

1. A backward masking task with simultaneous measurement of topographically mapped evoked potentials was performed by normal, schizophrenic, and patient control subjects. 2. Behavioral results replicated previous studies demonstrating schizophrenic deficit and to a lesser extent patient control deficit in this task. 3. Two competing theories of (A) defects in "gating" mechanisms or (B) failure in early stimulus "registration" processes were tested. 4. Topographical evoked response maps indicated a significant absence of a negative going wave in the 70-100 msec epoch in the schizophrenic group relative to both control groups. 5. As the 70-100 msec negativitity attenuation occurred during target presentation, and well before mask onset, it was concluded that schizophrenic deficit in this task consists of a failure in initial stimulus "registration" processes within the time allowed for stimulus availability. 6. Such defective mechanisms may be significant in the pathogenesis of schizophrenia.

Adolescent