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Biomedical subjects

J Brook

Publications and source records attributed to J Brook.

At least 37 records · Page 2Linked to original sources
PubMed1995

Hemolytic uremic syndrome in New Jersey.

In an 18-month study period, the authors identified 23 cases of hemolytic uremic syndrome (HUS) in New Jersey children. Increased identification and reporting of Escherichia coli O157:H7 are needed to prevent additional morbidity and mortality.

Adolescent↗
PubMed1994

Effects of low ambient levels of ozone and sulfates on the frequency of respiratory admissions to Ontario hospitals.

To investigate the acute respiratory health effects of ambient air pollution, the number of emergency of urgent daily respiratory admissions to 168 acute care hospitals in Ontario were related to estimates of exposure to ozone and sulfates in the vicinity of each hospital. Ozone levels were obtained from 22 monitoring stations maintained by the Ontario Ministry of the Environment for the period January 1, 1983 to December 31, 1988. Daily levels of sulfates were recorded at nine monitoring stations representing three different networks operated by the Ontario Ministry of the Environment and Environment Canada. Positive and statistically significant associations were found between hospital admissions and both ozone and sulfates recorded on the day of admission and up to 3 days prior to the date of admission. Five percent of daily respiratory admissions in the months of May to August were associated with ozone, with sulfates accounting for an additional 1% of these admissions. Ozone was a stronger predictor of admissions than sulfates. Positive and statistically significant (P < 0.05) associations were observed between the ozone-sulfate pollution mix and admissions for asthma, chronic obstructive pulmonary disease, and infections. Positive associations were also found in all age groups, with the largest impact on infants (15% of admissions associated with the ozone-sulfate pollution mix) and the least effects on the elderly (4%). Temperature had no effect on the air pollution-admission relationship. Ozone (lagged 1 day) and sulfates (lagged 1 day) displayed a positive association with respiratory admissions for 91 and 100% of the 168 acute care hospitals, respectively. Air pollution was not related to a class of nonrespiratory admissions, which served as a negative control, nor was it related to admissions in the winter months of December to March, when ozone and sulfate levels are low and when people spend a considerable amount of time indoors.

Adolescent↗
PubMed1994

Prevalence of childhood asthma across Canada.

BACKGROUND: A large cross-sectional study provided an opportunity to estimate the prevalence of childhood asthma in several regions across Canada. METHODS: In 1988, approximately 18,000 questionnaires were distributed to the families of 5-8 year old children in 30 communities from the following six regions across Canada: the interior of British Columbia, southeastern Saskatchewan, southwestern Ontario, the central region of Ontario, southern Quebec, and the Maritimes (Nova Scotia and Prince Edward Island). These communities were free of point-source air pollutants and selected to represent a range of ambient sulphate concentrations. In all 14,948 questionnaires were returned representing an 83% response rate. RESULTS: Currently present, physician-diagnosed asthma was reported for 4.7% of children by their parents. Persistent wheezing was reported for 13% and persistent cough for 5.9%. Asthma was most common in the two Maritime provinces (7.4%), and least common in British Columbia (3.3%) and Quebec (3.4%). Similar regional differences were seen for persistent cough, persistent wheeze, and also hospital separation rates for asthma which were approximately 800 per 100,000 for the Maritimes and 396 per 100,000 for British Columbia. Differences persisted despite adjustments for several host and environmental (indoor and outdoor) characteristics. CONCLUSIONS: The east coast of Canada may be an endemic area of asthma in Canada. If confirmed by objective measures of asthma, a detailed aetiologic investigation could enhance understanding of this phenomenon and the major environmental determinants of asthma morbidity in general.

Age Factors↗
PubMed1994

Air in the cavernous sinus following scalp vein cannulation.

A 7-month-old infant was found to have air in the cavernous sinus during a CT scan under general anaesthesia. An anterior scalp vein had been used to administer atracurium and contrast. The anatomy and precautions to prevent air embolism during scalp vein cannulation are discussed.

Catheterization, Peripheral↗
PubMed1994

Relationship of migrant status (refugee or immigrant) to mental health.

This study investigated and compared mental health levels among refugees and immigrants living in New Zealand. One hundred and twenty-nine Indochinese refugees, 57 Pacific Island immigrants and 63 British immigrants to New Zealand were surveyed. A questionnaire and the Hopkins Symptom Checklist-25 (HSCL-25) in English and in three Indochinese translations, were administered face-to-face. The hypothesis that migrant status (being a refugee or immigrant) affects mental health and that refugees experience more emotional distress than immigrants was only supported by the comparison with British immigrants. Both Indochinese refugees and Pacific Island immigrants experienced relatively low levels of mental health. However, the incidence of clinical depression and clinical total emotional distress tended to be higher among Indochinese refugees than in either immigrant group. In contrast clinical anxiety occurred most often among Pacific Islanders.

Adult↗
PubMed1993

An epidemiological study of disorders in late childhood and adolescence--I. Age- and gender-specific prevalence.

Developmental aspects of psychiatric disorders may be inferred from patterns of age differences in prevalence. Age-specific prevalences are provided for nine disorders in a general population sample of ages 10-20. Age and gender patterns for several disorders suggest developmental stage-associated risks. These include oppositional disorder in both genders and conduct disorder and major depression in girls. Major depression shows a pattern suggestive of a role for the onset of puberty. The prevalence of one or more disorders did not differ by age or gender. However, the pattern of specific diagnoses varied greatly by both age and gender.

Adolescent↗
PubMed1993

An epidemiological study of disorders in late childhood and adolescence--II. Persistence of disorders.

The persistence and new onset of psychiatric disorder were studied in a sample of 734 children from the general population. Diagnoses for six of the more prevalent disorders were generated from maternal and child interviews when the children were ages 9-18 and again 2 1/2 years later. Analyses demonstrated substantial levels of diagnostic persistence over the 2 1/2 year period for all diagnoses except major depression. With few exceptions persistence was roughly equivalent for age and gender subgroups. It is concluded that disorders assessed by structured interview of non-clinical samples of children cannot be dismissed as transitory.

Adolescent↗
PubMed1989

Mechanisms of the relation between perinatal problems, early childhood illness, and psychopathology in late childhood and adolescence.

Data on perinatal and early childhood somatic and psychological risk factors of a random sample of children were gathered in early to middle childhood and employed to examine the long-term risk of emotional and behavioral problems of late childhood and adolescence. 3 issues were addressed: First, can syndromic specificity of such effects be identified on scaled and diagnostic measures of syndromes? Second, are these effects attributable to excess risk of low-income children for both perinatal and later childhood problems? Third, are the intervening mechanisms identifiable as intellectual impairment, vulnerability to poor health, poor maternal caretaking, maternal rejection, or maternal stress associated with marital problems? Findings indicated that elevated risk was present for all syndromes, both at the scale level and at the diagnostic level. None of the examined intervening mechanisms fully accounted for the effects of early risks.

Adolescent↗
PubMed1987

Family factors related to the persistence of psychopathology in childhood and adolescence.

DATA collected in a large prospective longitudinal study of an epidemiological sample of children were employed to identify family risk factors for future psychopathology. Three data analytic models were used to distinguish between variables with effects on the subsequent onset of disorders, those in which increase in risk factor was accompanied by increase in disorder, and those specifically related to the duration of disorders present in the earlier assessment. Power assertive punishment techniques were most consistently related to future problems of the child, and children in unstable families who exhibited behavior or affective disorders in early childhood were more likely to have continuing problems 8 years later than were children in stable families. The relevance of these findings for primary, secondary, and tertiary prevention efforts is discussed.

Adolescent↗
PubMed1984

Tailor-made agarose-based reactive beads for hemoperfusion and plasma perfusion.

Composite beads of approximately 1 mm diameter, made of crosslinked agarose and containing Fuller's Earth or zirconium oxide powders, were prepared and used in extracorporeal systems for blood detoxification. The former was used for the removal of Paraquat, while the latter was used to remove inorganic phosphate from hyperphosphatemic animals with or without acute renal failure. The high surface area of the powder, combined with the low resistance to diffusion in the crosslinked agarose matrix, are highly advantageous. The crosslinking provides high mechanical strength, heat stability, prolonged shelf life, good blood flow characteristics, and prevents the release of fine particles into the blood. Crosslinked agarose beads of 1 mm diameter, containing chemically-bound heparin were also prepared, and used as a model for direct contact removal of LDL-cholesterol from the blood of familial hypercholesterolemic patients by hemoperfusion. The high capacity of these beads (over 5 mg LDL/mL beads) indicates that this clinical modality can replace the highly expensive plasmapheresis procedure presently used.

Animals↗
PubMed1981

Human chorionic gonadotropin maintains plasma progesterone at pregnancy levels in rhesus monkeys.

Peripheral plasma progesterone (P) levels in the rhesus monkey remain relatively constant both during the latter half of pregnancy and for long periods after fetectomy (removal of the fetus with the placenta left in situ) or ovariectomy. The constancy is maintained despite what appears to be reciprocal changes in the relative contributions of ovary and placenta. Placental regulation of the corpus luteum is likely, but it is not known if the corpus luteum responds to a gonadotropic stimulus in the later stages of pregnancy. In this study, we have investigated the effects of hCG administration in postdelivery monkeys (normally pregnant, fetectomized, ovariectomized and sham ovariectomized animals) and have determined if hCG administration maintains plasma P at pregnancy levels. hCG maintained P at pregnancy levels after surgical removal of the conceptus near term in both normally pregnant and previously fetectomized monkeys over a 7-day treatment period. hCG treatment after normal delivery maintained P levels in sham-ovariectomized but not in ovariectomized monkeys over an 8-day treatment period. The magnitude of the response to hCG declines over the treatment period in all groups except fetectomized monkeys, although hCG levels in the peripheral plasma are quite constant. These results indicate that the ovary of late pregnancy is fully capable of producing P at normal values and is responsive to this gonadotropin.

Animals↗
PubMed1977

Leukocyte alkaline phosphatase levels in multiple myeloma.

Leukocyte alkaline phosphatase levels (LAPL's) were determined in 62 patients with multiple myeloma over a 13-year period. Sixty of the 62 myeloma patients had consistently elevated LAPL's, one patient had normal LAPL, and one patient had an initially normal LAPL which later increased. Elevated LAPL's could not be correlated with age, hemoglobin levels, white blood counts, or elevation of the blood urea nitrogen. LAPL's did not change during objective or subjective responses to chemotherapy or with progression of disease. We suggest that some feature of myeloma may "turn on" an abnormal clone of cells which may be responsible for the elevated LAPL's in patients with multiple myeloma.

Adult↗