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Biomedical subjects

J E Garrett

Publications and source records attributed to J E Garrett.

At least 55 records · Page 3Linked to original sources
PubMed1991

Emergency room care of asthmatics: a comparison between Auckland and Toronto.

We compared emergency room visits for the treatment of asthma in two large downtown teaching hospitals: one in Auckland, New Zealand and one in Toronto, Canada. We wished to determine whether the differences in asthma mortality between New Zealand and Canada were reflected in different patterns of emergency room use or physician management. Emergency room use during the past decade was enumerated in both hospitals, and charts containing the sole diagnosis of asthma were reviewed in detail for a defined study period in 1986. In both Toronto and Auckland, the number of emergency visits for asthma had increased significantly in the past decade (P less than .015 but the rate of rise was significantly higher in Auckland (P less than .05). In Auckland, 27% of asthmatics were admitted whereas in Toronto significantly fewer (16%) were admitted (P less than .0005). Objective measures of pulmonary function were documented more frequently by emergency room physicians in New Zealand than in Canada (90% versus 48%; P less than .0005). Pulmonary function measurement was primarily by peak flow meter in Auckland and most commonly by spirometer in Toronto so that pulmonary function measurements could not be compared directly between centers. In both centers, however, admitted patients had significantly lower pulmonary function indices than discharged patients. In New Zealand, mean peak flow was 38% of the predicted value among all asthmatics assessed; in Toronto, mean FEV1 was 47% of predicted. In Toronto, pulmonary function measurements were most likely to be missing among presumably healthier discharged patients. Pulse rate, respiratory rate, and pulsus paradoxus were documented more consistently in Auckland than in Toronto.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1990

Asthma and the employment experience.

Previous asthma research has had a medical focus, and only one study has investigated the relationship between asthma and employment. This study describes the employment experience in relation to occupational choice and career advancement in 93 sequentially selected adult asthmatics attending a hospital based asthma clinic serving a socially disadvantaged urban population. Repeated hospital admissions and frequent asthma related sick leave from work were identified as contributing factors to employer discrimination, job dismissal, and lack of career advancement. Seventy-seven percent had not informed their employers of their asthma and 32% of those currently employed stated that getting time off work was a problem in relation to Asthma Clinic attendance. Of those not employed, 22.9% were receiving sickness or invalid benefits and 8.3% had lost their jobs because of asthma. This study illustrates how the stigma attached to the diagnosis of asthma in this community may not only impact negatively on employment opportunity, but also on asthma care.

Adolescent↗
PubMed1990

A spermatozoa-associated factor regulates proenkephalin gene expression in the rat epididymis.

The gene encoding the opioid peptide precursor preproenkephalin is expressed at high levels in the initial segment of the adult rat epididymis. Expression is localized to principal cells, the secretory epithelial cells lining the epididymal duct. During development, epididymal proenkephalin mRNA levels show a pronounced increase at about 44 days of age, coincident with the initial entry of spermatozoa into the epididymal lumen. Hypophysectomy leads to a 60-fold decrease in epididymal proenkephalin mRNA levels. Testosterone replacement can prevent this decline in a manner consistent with an effect upon spermatogenesis. Castration studies demonstrate that a gonadal factor other than testosterone directly regulates epididymal proenkephalin expression, and the results of efferent duct ligation suggest that this factor must be supplied through an intact connection of the testis and epididymis. Proenkephalin mRNA levels in the epididymis correlate with the decline and reappearance of spermatozoa induced by the alkylating agent busulphan. Thus, the developmental profile of proenkephalin expression, coupled with the results of both surgical and pharmacological manipulations of the reproductive tract, indicate that spermatozoa, or a spermatozoa-associated factor, regulate proenkephalin gene expression in the epididymis.

Androgens↗
PubMed1989

Attendance failure at Middlemore Hospital asthma clinic.

A population of 138 outpatients' sociodemographic and sociobehavioural characteristics and clinic organisational factors were studied in response to a concern about poor attendance rates at Middlemore Hospital's asthma clinic. Low and nonattendance was found to be higher among Maoris (44.7%) and Pacific Islanders (31.6%), outpatients of lower socioeconomic status (SES group 5 and 6, 55.3%), and those referred from the accident and emergency (A & E) department (66%). Migration out of the south Auckland region was common among the group of low attending outpatients (23.9%). Since neither the clinic nor the outpatients' general practitioners were aware of this group's migrational movement there exists a large population who do not have regular medical care and are therefore at risk of significant morbidity or mortality from their asthma.

Black or African American↗
PubMed1989

Reasons for racial differences in A & E attendance rates for asthma.

To determine whether racial differences in the severity of asthma accounted for the higher accident and emergency department (A & E) use by Pacific Islanders and Maoris, a study of A & E users at Middlemore Hospital and of asthmatics using urgent medical services was undertaken. Europeans reported more daytime symptoms of asthma (p less than 0.0005) and were on more medications (p less than 0.005) than Pacific Islanders, with Maoris intermediate (ns). Relative to the perceived severity of their asthma, both Maoris and Pacific Islanders lost more time from work or school and used hospital services more than European asthmatics using A & E. The increased use of A & E by Maori and Pacific Island asthmatics seemed not attributable to the intrinsic severity of their asthma and was better explained by ethnic, socioeconomic and sociocultural factors. Pacific Islanders had less self management skills and, like Maoris, were less likely to be on prophylactic medications relative to oral bronchodilator use and these factors likely contributed to their increased morbidity.

Adolescent↗
PubMed1989

Translational control of germ cell-expressed mRNA imposed by alternative splicing: opioid peptide gene expression in rat testis.

The three genes encoding the opioid peptide precursors (prodynorphin, proenkephalin, and proopiomelanocortin) are expressed in the rat testis. The sizes of the three opioid mRNAs in the testis differ from the sizes of the corresponding mRNAs in other rat tissues in which these genes are expressed. The smaller testicular proopiomelanocortin mRNA has previously been demonstrated to arise from alternative transcriptional initiation. In the present study, we found that the smaller testicular prodynorphin mRNA, expressed in Sertoli cells, results from alternative mRNA processing. Exon 2, which makes up 5' untranslated sequence, is removed from the mature transcript. Polysome analysis of brain and testis RNA indicates that the alteration of the prodynorphin leader sequence in the testis-specific transcript does not affect the efficiency of translation of this mRNA. The larger testicular proenkephalin transcript, expressed in developing germ cells, also results from alternative mRNA processing. Alternative acceptor site usage in the splicing of intron A results in a germ cell-specific proenkephalin transcript with a 491-nucleotide 5' untranslated leader sequence preceding the preproenkephalin-coding sequence. Polysome analysis indicates that this germ cell-specific proenkephalin mRNA is not efficiently translated. Mechanisms by which alternative mRNA splicing may serve to confer translational regulation upon the testicular proenkephalin transcript are discussed.

Animals↗
PubMed1989

Composite transposable elements in the Xenopus laevis genome.

Members of two related families of transposable elements, Tx1 and Tx2, were isolated from the genome of Xenopus laevis and characterized. In both families, two versions of the elements were found. The smaller version in each family (Tx1d and Tx2d) consisted largely of two types of 400-base-pair tandem internal repeats. These elements had discrete ends and short inverted terminal repeats characteristic of mobile DNAs that are presumed to move via DNA intermediates, e.g., Drosophila P and maize Ac elements. The longer versions (Tx1c and Tx2c) differed from Tx1d and Tx2d by the presence of a 6.9-kilobase-pair internal segment that included two long open reading frames (ORFs). ORF1 had one cysteine-plus-histidine-rich sequence of the type found in retroviral gag proteins. ORF2 showed more substantial homology to retroviral pol genes and particularly to the analogs of pol found in a subclass of mobile DNAs that are supposed retrotransposons, such as mammalian long interspersed repetitive sequences, Drosophila I factors, silkworm R1 elements, and trypanosome Ingi elements. Thus, the Tx1 elements present a paradox by exhibiting features of two classes of mobile DNAs that are thought to have very different modes of transposition. Two possible resolutions are considered: (i) the composite versions are actually made up of two independent elements, one of the retrotransposon class, which has a high degree of specificity for insertion into a target within the other, P-like element; and (ii) the composite elements are intact, autonomous mobile DNAs, in which the pol-like gene product collaborates with the terminal inverted repeats to cause transposition of the entire unit.

Amino Acid Sequence↗
PubMed1989

Characterization of the rat prodynorphin gene.

The structure of full-length rat prodynorphin cDNA and the corresponding gene has been determined. The 2400 base rat prodynorphin mRNA is encoded by four exons. Exons 1 and 2 encode the majority of the 5'-untranslated sequence, while exons 3 and 4 contain the translated region; the entire 3' -untranslated region is contained on exon 4 as well. RNase protection studies, in which a genomic DNA fragment was used to generate a cRNA hybridization probe, have determined the major transcriptional initiation site for both brain and testicular prodynorphin mRNA. Transient expression of transfected fusion genes containing the 5'-flanking DNA of the rat prodynorphin gene linked to the structural sequence of a reporter gene has been used to identify specific genomic DNA fragments from the prodynorphin gene locus which are capable of acting as transcriptional promoters. Multiple regions of genomic DNA appear to have transcriptional promoter activity when introduced into various eukaryotic cell lines.

Amino Acid Sequence↗
PubMed1989

Human chorionic gonadotropin regulates expression of the proenkephalin gene in adult rat Leydig cells.

The gene encoding the proenkephalin precursor is expressed in both progenitor spermatogenic cells and somatic cells in the rat testis. The 1750-nucleotide (nt) germ cell-specific proenkephalin mRNA is the predominant form detected in the adult rat. The 1400-nt somatic cell form has previously been shown to be expressed in cultured Sertoli cells derived from sexually immature rats, and FSH treatment increases expression of the proenkephalin gene in that experimental system. In the present report we demonstrate that the 1400-nt proenkephalin transcript is present in a freshly isolated, enriched preparation of adult rat Leydig cells. This gene continues to be expressed when the Leydig cells are maintained in primary culture. Treatment of cultured Leydig cells with hCG or a cAMP analog leads to a rapid increase in proenkephalin-mRNA levels. The expression of the proenkephalin gene throughout rat development in the two major somatic cell types of the testis further suggests that proenkephalin-derived peptides play an important role in modulating testicular function. The gene encoding another of the opioid peptide precursors, POMC, has previously been reported to be expressed in rat Leydig cells. We were unable to detect POMC transcripts in cultured Leydig cells. POMC mRNA is abundant in a germ cell-enriched cell fraction.

Animals↗
PubMed1989

Uterine secretory alterations coincident with embryonic mortality in the gilt after exogenous estrogen administration.

Sixteen crossbred gilts were assigned randomly to receive either an i.m. injection of sesame oil (control) or estrogen (E), 5 mg of estradiol valerate, on d 9 and 10 of pregnancy. Gilts were unilaterally hysterectomized on either d 12 and 14 or 16 and 18. Uterine horns were flushed with 20 ml of .9% sterile NaCl solution to recover conceptus tissue. Conceptuses and endometrial explants were cultured for 24 h with 100 microCi [3H] leucine in 15 ml of minimum essential media. After dialysis, culture media were submitted to 2D-polyacrylamide gel electrophoresis and incorporated proteins were analyzed by fluorography. Normal, intact conceptus tissue was recovered from control gilts. Estrogen-treated gilts flushed on d 12 and 14 contained intact conceptuses; however, uteri from two gilts on d 16 and three on d 18 contained degenerating conceptus tissue. Comparison of endometrial polypeptides synthesized in vitro indicated an alteration in E-treated gilts on d 12 through 18. Although similar polypeptides were present, a band of polypeptides with a Mr of approximately 30,000 and pI from 7.9 to 8.9 and a larger, acidic polypeptide (Mr = 100,000, pI 3.5 to 5.0) were faint or absent in E-treated gilts. Conceptuses elongated normally in the altered uterine environment, but failed to survive past d 14 in E-treated gilts. Although loss of specific polypeptides in E-treated gilts coincides with conceptus death, their function in conceptus development or attachment is unknown.

Abortion, Veterinary↗
PubMed1988

Characteristics of asthmatics using an urban accident and emergency department.

The demographic characteristics of patients attending the Middlemore Hospital accident and emergency department with asthma were studied prospectively over a 3 month period. Pacific Islanders and Maoris used A & E more and were more frequently admitted because of asthma than Europeans (p less than 0.0001). Independent of race, patients living in close proximity were more likely to attend A & E and to be admitted than patients living distant from hospital (p less than 0.0001). When compared with asthmatics referred by a general practitioner, self-referred asthmatics attended more frequently out of hours (p less than 0.05) and were disproportionately of lower socioeconomic classes (p less than 0.01). Eighty two percent of asthmatics perceived A&E as the most appropriate place to have their acute attacks managed. The demographic characteristics of those using A & E suggests that there are attitudinal, organisational and financial barriers to primary health care in the community which may have contributed to a shift from community to hospital based management of acute asthma, and this may explain some of the increase in hospital admissions for asthma.

Acute Disease↗
PubMed1988

Trends in the use of an urban accident and emergency department by asthmatics.

To examine the possible relationship between the increase in asthma admission rates and the use of the accident and emergency department (A & E) for the management of asthma, a retrospective study of asthma admissions and A & E attendances was undertaken at Middlemore Hospital. Admission rates for adult asthma doubled between 1974 and 1985 (p less than 0.001). Yearly A & E attendance rates for adult asthma also doubled between 1977 (when data collection began) and 1985 (p less than 0.01), and could be largely explained on the basis of increased reattendance (p less than 0.001). These trends suggest that the hospital is being used in a primary care role for the treatment of acute asthma and that self-referral is encouraged. A dependence on A & E by frequent attenders may be a barrier to nonacute ongoing medical care in the community and may lead to the seeking of care for attacks later than if a general practitioner (GP) was used. Dependence on and attendance at A & E may lead to an increased risk of admission and thus may have contributed to the increase in the admission rate for asthma.

Adolescent↗
PubMed1988

Effect of exogenous progesterone on prostaglandin F2 alpha release and the interestrous interval in the bovine.

The present study was developed to determine if administration of progesterone, early in the estrous cycle of the cow, stimulated an advanced pulsatile release of PGF2 alpha from the uterine endometrium resulting in a decreased interestrous interval. Twenty-three cyclic beef cows were randomly assigned to receive either sesame oil or progesterone (100 mg) on Day 1, 2, 3 and 4 of the estrous cycle. Peripheral plasma concentrations of progesterone and the metabolite of prostaglandin F2 alpha, 15-keto-13,14-dihydro-prostaglandin F2 alpha (PGFM) were measured by radioimmunoassay. Administration of exogenous progesterone increased peripheral plasma concentration of progesterone in treated (3.67 ng/ml) compared to control (1.28 ng/ml) cows from Day 2 through 5 of the estrous cycle. Progesterone administration shortened the interestrous interval (16.7 d) compared to controls (21.6 d). The shortened interestrous intervals in treated cows resulted from an earlier decline in peripheral plasma progesterone. Decline of peripheral plasma progesterone concentrations is coincident with an increased pulsatile release of PGFM in both progesterone treated and control cows. Results indicate that administration of exogenous progesterone stimulates an earlier maturation of endometrial development, causing an advanced release of PGF2 alpha which shortens the interestrous interval of the cow.

Animals↗
PubMed1988

Evidence for maternal regulation of early conceptus growth and development in beef cattle.

Fifty-one cyclic beef cows were mated with fertile bulls. At 36 h after the start of oestrus, cows were assigned to receive sesame oil (controls) or progesterone (100 mg) on Days 1, 2, 3 and 4 of pregnancy. Peripheral plasma concentration of progesterone was measured until slaughter on Days 5 or 14. Cows were randomly assigned to be slaughtered on Days 5 or 14 or remain intact and palpated per rectum on Day 40 to verify pregnancy. Uteri on Days 5 and 14 were flushed for recovery of luminal protein and conceptus tissue. Conceptus and endometrial tissues were cultured with [3H]leucine and submitted to two-dimensional-PAGE and fluorography. Administration of progesterone increased peripheral plasma progesterone concentration on Day 2-5. Conceptuses recovered from progesterone-treated cows on Day 14 were advanced in development compared to conceptuses from control cows. Conceptuses recovered from progesterone-treated cows were viable as polypeptides associated with maintenance of pregnancy in cattle were synthesized and released at an earlier time and pregnancy was maintained beyond Day 40. Early progesterone stimulation altered the synthesis and release of polypeptides from endometrial explant cultures on Day 5. Results indicate a role of progesterone in the maternal regulation of conceptus growth and development in early pregnancy of cattle.

Animals↗
PubMed1987

Influence of supplemental nitrogen source on digestion of nitrogen, dry matter and organic matter and on in vivo rate of ruminal protein degradation.

Seven Holstein steers (340 kg) fitted with ruminal, duodenal and ileal cannulae were used to measure the influence of supplemental N source on digestion of dietary crude protein (CP) and on ruminal rates of protein degradation. Diets used were corn-based (isonitrogenous, 12% CP on a dry matter basis, and isocaloric, 80% total digestible nutrients) with urea, soybean meal (SBM), linseed meal (LSM) or corn gluten meal (CGM) as supplemental N. Ruminal ammonia N concentrations were higher (P less than .05) in steers fed LSM than in those fed CGM, but did not differ from those in steers fed urea or SBM (11.7, 6.7, 9.1 and 9.2 mg/100 ml, respectively). Due to the high degradability of urea, ruminal digestion of dietary CP was greater (P less than .05) in steers fed urea than in those fed CGM, but intermediate in steers fed SBM and LSM (58.4, 48.8, 53.1 and 53.9%, respectively). Flow of bacterial nonammonia N to the duodenum was highest (P less than .05) in steers fed SBM or LSM, intermediate (P less than .05) for urea and lowest (P less than .05) for CGM (86.8, 86.1, 76.3 and 65.9 g/d, respectively). Efficiency of bacterial protein synthesis was lowest in steers fed CGM and differed (P less than .05) from SBM (15.6 vs 21.8 g N/kg organic matter truly digested, respectively). Rate of ruminal digestion for SBM-CP differed (P less than .05) from that of CGM-CP but not from that of LSM-CP (17.70, 5.20 and 10.13%/h, respectively). The slow rate of ruminal degradability of CGM resulted in increased amounts of dietary protein reaching the intestinal tract but lower amounts of bacterial protein, thus intestinal protein supply was not appreciably altered.

Animal Nutritional Physiological Phenomena↗
PubMed1986

Changes in outcome for patients with bronchial carcinoma: the Green Lane Hospital experience.

To evaluate the effect of changes in the management of bronchial carcinoma at Green Lane Hospital, we have made a retrospective analysis of patients presenting in 1978 and 1979. Previous reviews from this unit provided a comparison. There was a modest improvement in the 5-year survival for the group as a whole (4.3% in 1955-65 to 7.7% in 1978-79). For patients undergoing surgical resection, the improvement in 5-year survival from 22% to 40.5% appeared mainly due to better pre-operative selection. Patients with non-small-cell carcinoma selected for radical radiotherapy had a 5-year survival of 7.2%. During the study period, radiotherapy alone was replaced by a combination of chemotherapy and radiotherapy for limited small-cell carcinoma. Median survival improved from six months to 13.5 months and was better than the 7.5 months obtained with surgical resection in 1955-65. Twenty-four patients were referred as a result of mass miniature x-ray (MMR) at a rate of 22/100 000 radiographs taken. Five-year survival for the MMR group was statistically better than for the rest of the group (29% compared to 7.2%; p less than 0.001), supporting the practice of x-raying smokers over the age of 45 annually.

Adult↗