Biomedical subjects

J M Wallace

Publications and source records attributed to J M Wallace.

At least 73 records · Page 4Linked to original sources

PubMed1997

Maternal endocrine status in relation to pregnancy outcome in rapidly growing adolescent sheep.

It has previously been reported that high nutrient intakes which promote rapid maternal growth throughout pregnancy are associated with poor pregnancy outcome when compared with normally growing adolescent animals. The present study examined the maternal plasma concentrations of a number of putative endocrine regulators of nutrient partitioning between the maternal and fetal compartments in relation to placental and fetal growth in this novel experimental paradigm. Embryos were recovered on day 4 after oestrus from superovulated adult ewes that had been inseminated using semen from a single sire and synchronously transferred, in singleton, to the uterus of peripubertal adolescent recipients (n = 38), which had been induced to ovulate at 32 weeks of age (live weight 47.4 +/- 0.4 kg). Post-transfer, the adolescent recipients were offered a high (n = 21) or moderate (n = 17) level of a complete diet calculated to achieve rapid (RMG) or normal (NMG) maternal growth rates. After day 100 of gestation, the feed intake of the NMG group was adjusted weekly to meet the increasing nutrient demands of the gravid uterus. Pregnancy rate following embryo transfer was higher (P < 0.05) in the RMG (90%) than in the NMG (59%) group. For ewes delivering live young at term, liveweight gain during the first 100 days of gestation was 294 +/- 12.9 and 84 +/- 4.7 g/day for the RMG (n = 16) and NMG (n = 10) groups respectively, and body condition score immediately prior to parturition was higher in RMG than in NMG ewes (2.9 +/- 0.04 vs 1.9 +/- 0.15 score units respectively, P < 0.001). For the RMG and NMG groups respectively, mean placental weight was 327 +/- 18.1 and 485 +/- 16.6 g with lamb birth weights of 3.49 +/- 0.13 and 4.82 +/- 0.21 kg (P < 0.001). The reduction in placental mass in the RMG group reflected a decrease in the number (P < 0.001) and size (P < 0.01) of the fetal cotyledons. The duration of gestation was shorter (P < 0.001) and colostrum yield at parturition lower (P < 0.001) in the RMG group. Maternal insulin concentrations, determined three times weekly, were higher (P < 0.001) throughout gestation in the RMG group and irrespective of treatment group were negatively correlated (P < 0.01) with placental weight and lamb birth weight. High glucose levels throughout gestation and a decreased response to an exogenous insulin challenge on day 95 of gestation implied a degree of insulin resistance in the RMG group but, in spite of these high maternal glucose concentrations, the reduced size of the placenta probably constrained fetal growth. Maternal IGF-I levels determined weekly, were elevated (P < 0.001) during the second and third trimester in RMG versus NMG groups and a sustained elevation in maternal tri-iodothyronine and thyroxine concentrations was evident in the RMG group from mid-gestation. In contrast, GH pulse frequency and mean GH concentrations, determined on day 68 and 122 of gestation, were lower (P < 0.05) in the RMG group, and irrespective of treatment group, were correlated negatively with feed intake and positively with placental weight and colostrum yield at parturition. Progesterone concentrations were lower in the RMG group during the second and third trimesters (P < 0.001) and, irrespective of treatment group, were positively associated (P < 0.001) with placental weight, gestation length and colostrum yield. These results suggest that in pregnant adolescent sheep on high dietary intakes, elevated insulin and IGF-I levels ensure that the anabolic drive to maternal tissue synthesis is established during early gestation at the expense of placental growth. The consequent restriction in placental transport capacity is the primary limitation to fetal growth and reduced GH and placental progesterone secretion may impair colostrum production.

Animal Nutritional Physiological Phenomena↗

PubMed1997

Special problems of the asthmatic patient.

Environmental factors and physical activity present special problems for the asthmatic patient. Bronchoconstriction due to workplace exposure is one of the most common forms of occupational lung disease and has similar pathogenic mechanisms to nonoccupational asthma. Diagnosing occupational asthma may be difficult because the association between symptoms during or after work and a causative agent may be obscure. Nevertheless, it is important to recognize occupational asthma because even trace amounts of the causative agent may trigger bronchoconstriction, and the affected employee must almost always avoid exposure. Bronchoconstriction induced by exercise has affected the lifestyles of many asthmatic patients and has created special problems for numerous accomplished athletes. Although exercise-induced asthma (EIA) characteristically occurs immediately after cessation of exertion, a recent study suggests that it may sometimes begin during sustained exertion. Asthmatic patients who participate in winter sports are particularly susceptible to EIA. Vocal cord dysfunction in athletes who participate in intense competition can mimic EIA. In addition to beta-agonists used immediately before exercise, newer drugs that show promise in the treatment of EIA include the leukotriene inhibitors and furosemide. Asthmatic patients are susceptible to extremes in atmospheric pressure and have increased risk of barotrauma and arterial gas embolism during scuba diving. During longer stays at high altitude, however, asthmatic patients appear to have attenuated bronchial responsiveness.

Adrenergic Agonists↗

PubMed1997

Cytokines in human breast milk.

In early life humans derive all their nutrients from milk. Human milk provides the neonate with not only a food source but also a source of biologically active molecules such as hormones, growth factors and cytokines. Cytokines are multifunctional glycoproteins involved in cell communication and immune system activation. Two of these cytokines, granulocyte-colony stimulating factor (G-CSF) and interleukin-6 (IL-6), are present in variable concentrations in human milk. We measured G-CSF and IL-6 concentrations in healthy nursing mothers. The 30 milk samples assayed contained G-CSF levels from 14 pg/mL to > 2500 pg/mL. Of the 28 milk samples assayed for IL-6, 24 contained levels from 0.81 pg/mL to 306 pg/ mL. The remainder had levels below the detection limit of the assay. These biologically active molecules may play a role in neonatal growth and development, and may also protect the infant against infection.

Granulocyte Colony-Stimulating Factor↗

PubMed1997

High refractive errors and the accident/incident rate in Canadian medical category 1 pilots.

BACKGROUND: Since 1982, the Canadian Civil Aviation Medicine Division has medically certified to Category 1 standard commercial and airline transport pilots whose visual correction was in excess of +/- 3.5 diopters (D). METHOD: A review between the years 1982 and 1991 of the 253 pilots who had been medically certified, although they were outside the standard, was conducted. We determined if there was any difference in the accident/incident rate in this group as compared with the Canadian general aviation population standardized to a rate per 100,000 flying hours. The 253 pilots were divided into two groups with Group A having a refractive error outside the range +/- 5.7 D and Group B having a refractive error range of +/- 3.5 to +/- 5.6 D. RESULTS: The Group A rate was within the expected range of accidents and incidents per 100,000 flying hours. The accident/incident rate in Group B was significantly lower than the expected average. CONCLUSION: In conclusion, the Canadian Civil Aviation Medicine Division's policy on granting "flexibility" to applicants with moderate to high refractive errors has not affected adversely the accident or incident rate and therefore has not compromised aviation safety.

Accidents, Aviation↗

PubMed1996

Lack of usefulness of radiographic screening for pulmonary disease in asymptomatic HIV-infected adults. Pulmonary Complications of HIV Infection Study Group.

OBJECTIVE: To determine the use of chest radiographs in the screening of asymptomatic adults infected with the human immunodeficiency virus (HIV). METHODS: A prospective, multicenter study of the pulmonary complications of HIV infection in a community-based cohort of persons with and without HIV infection. The subjects included 1065 HIV-seropositive subjects without the acquired immunodeficiency syndrome at the time of enrollment: 790 homosexual men, 226 injection drug users, and 49 women with heterosexually acquired infection. Frontal and lateral chest radiographs were performed at 3-, 6-, and 12-month intervals, CD4 lymphocyte measurements at 3- and 6-month intervals, tuberculin and mumps skin tests at 12-month intervals, and medical histories and physical examinations at 3- and 6-month intervals. Pulmonary diagnoses that occurred within 2 months following each radiograph were analyzed and correlated with the radiographic results. RESULTS: Evaluable screening chest radiographs (5263) were performed in HIV-seropositive subjects while they were asymptomatic; of these, 5140 (98%) were classified as normal and 123 (2%) as abnormal. A new pulmonary diagnosis was identified within 2 months following a screening radiograph in 55 subjects. Only 11 of these subjects had abnormal radiographs; the sensitivity of the radiograph was 20%. The sensitivity was similarly low at baseline, within each transmission category, and in subjects whose CD4 lymphocyte counts were less than 0.2 x 10(9)/L (200/microL). The types of pulmonary diseases that occurred were similar in the subjects with normal and abnormal screening radiographs. CONCLUSION: Screening chest radiography in asymptomatic HIV-infected adults is unwarranted because the diagnostic yield is low.

AIDS-Related Opportunistic Infections↗

PubMed1996

Acceleration of cheese ripening.

The characteristic aroma, flavour and texture of cheese develop during ripening of the cheese curd through the action of numerous enzymes derived from the cheese milk, the coagulant, starter and non-starter bacteria. Ripening is a slow and consequently an expensive process that is not fully predictable or controllable. Consequently, there are economic and possibly technological incentives to accelerate ripening. The principal methods by which this may be achieved are: an elevated ripening temperature, modified starters, exogenous enzymes and cheese slurries. The advantages, limitations, technical feasibility and commercial potential of these methods are discussed and compared.

Cheese↗

PubMed1996

Viruses and other miscellaneous organisms.

Pulmonary infections caused by several types of viruses and other miscellaneous organisms may cause disease in HIV infection. Evidence suggests that pulmonary conditions may result from infections of the lung by HIV itself. Other viruses, most commonly cytomegalovirus, may be primary perpetrators of pneumonitis or may contribute to diseases caused by coexisting infections. Although diagnosis and assessment of the clinical significance of these infections may be difficult, their recognition is of practical importance because potentially effective therapeutic agents are available for several of them. Miscellaneous infections such as pulmonary toxoplasmosis and pertussis are other uncommon but potentially treatable complications of HIV disease.

AIDS-Related Opportunistic Infections↗

PubMed1996

Enhanced diallyl trisulfide has in vitro synergy with amphotericin B against Cryptococcus neoformans.

Although amphotericin B remains the drug of choice for systemic fungal infections, its use is limited by considerable side effects. In The Peoples' Republic of China, commercial Allium sativum derived compounds are widely used as an antifungal drug to treat systemic fungal infections. To evaluate the scientific merit of using A. sativum derived compounds as antifungal agents, we studied a Chinese commercial preparation, allitridium. This preparation contained mainly diallyl trisulfide as confirmed by high performance liquid chromatography. Allitridium, with and without amphotericin B, was tested to determine its efficacy in killing three isolates of Cryptococcus neoformans. The minimum inhibitory concentration of the commercial preparation was 50 micrograms/ml and the minimum fungicidal concentration was 100 micrograms/ml against 1 x 10(5) organisms of C. neoformans. In addition, the commercial preparation was shown to be synergistic with amphotericin B in the in vitro killing of C. neoformans. This study demonstrates that diallyl trisulfide and other polysulfides possess potent in vitro fungicidal effects and their activity is synergistic with amphotericin B. These observations lend laboratory support for the treatment of cryptococcal infections with both amphotericin B and the Chinese commercial preparation.

Allyl Compounds↗

PubMed1996

Reliability of anergy skin testing in persons with HIV infection. The pulmonary Complications of HIV Infection Study Group.

Testing with antigens that elicit delayed-type cutaneous hypersensitivity reactions is commonly used to evaluate immune competence in persons infected with the human immunodeficiency virus; however, the reliability of such testing has not been determined. We performed serial testing with tuberculin, mumps, and Candida antigens in 491 HIV-infected persons and found that 30% of persons who initially had no reaction (0 mm) to any of the three antigens, and, thus, were considered to be anergic, had reaction to the mumps or Candida antigen when they were retested 12 months later. We also examined the results of mumps antigen tests in 50 subjects who had a negative tuberculin tests after an initial positive test. The mumps antigen test was positive in 39% of the subjects when the tuberculin test was falsely negative. We conclude that tests commonly used to define anergy cannot reliably identify the anergic state. Moreover, using the mumps antigen to aid in the interpretation of the tuberculin test will often lead to erroneous conclusions. These data indicate that the results of anergy testing should not be used to make individual patient decisions concerning preventive therapy for tuberculosis.

Administration, Cutaneous↗

PubMed1996

Effect of continuous infusion of thyrotrophin-releasing hormone on plasma prolactin and on ovarian activity in melatonin-treated ewes.

Twelve anoestrous ewes maintained under natural photoperiod at 57 degrees N received an oral dose of 3 mg melatonin daily at 15:00 h from 1 May. Starting 41 days later and extending from 11 June until 5 September, six of the ewes were also infused continuously with 0.8 mg thyrotrophin-releasing hormone (TRH) day-1 via subcutaneous osmotic minipumps. The remaining six ewes acted as controls. Behavioural oestrus, ovulation rate and luteal function were determined by exposure to a vasectomized ram, laparoscopy and the measurement of progesterone in peripheral plasma, respectively. TRH infusion stimulated a sustained increase (P < 0.001) in plasma concentrations of thyroxine, tri-iodothyronine and prolactin (thyroxine: 158 +/- 9.3 and 65 +/- 7.7 nmol l-1 for TRH-infused and control ewes, respectively; tri-iodothyronine, 2.6 +/- 0.12 and 1.1 +/- 0.19 nmol l-1 and prolactin, 57 +/- 12 and 11 +/- 2 micrograms l-1). No ewes were in oestrus before TRH infusion and the mean number of behavioural oestrous cycles per ewe during the infusion period was 1.3 +/- 0.33 and 2.5 +/- 0.34 for TRH-infused and control ewes, respectively (P < 0.05). Corresponding mean intervals from 1 May to the onset of the first luteal phase (progesterone > 1 ng ml-1) were 88 +/- 8.9 and 79 +/- 3.5 days (not significant). TRH infusion had no effect on the mean numbers of corpora lutea (1.7 +/- 0.14 and 1.6 +/- 0.20 for TRH-infused and control ewes, respectively), but was associated with a lower mean incidence of normal luteal phases (1.5 +/- 0.43 versus 2.7 +/- 0.21, P = 0.052). Abnormalities in luteal function included delayed initial expression, extended ovarian cycles, suprabasal periovulatory progesterone concentrations and protracted periods of low progesterone secretion between successive ovarian cycles. Thus continuous TRH infusion suppressed plasma prolactin, doubled the circulating concentrations of thyroxine and tri-iodothyronine, and was associated with a wide range of abnormalities in ovarian function and endocrine status, the nature of which varied between ewes.

Animals↗

PubMed1996

Nutrient partitioning and fetal growth in rapidly growing adolescent ewes.

A highly controlled model to investigate nutrient partitioning and the control of fetal growth in the rapidly growing adolescent sheep is described. Embryos recovered from superovulated adult ewes inseminated by a single sire were transferred in singleton to the uterus of prepubertal adolescent recipients induced to ovulate at 21 weeks of age (liveweight 44.4 +/- 0.38 kg). After embryo transfer, the adolescent recipients were individually offered a high (n = 28) or low (n = 20) quantity of a complete diet calculated to achieve rapid (RMG) or normal (NMG) maternal growth rates. After day 100 of gestation the feed intake of the NMG group was adjusted weekly to meet the increasing nutrient demands of the gravid uterus. The proportion of adolescent recipients initially conceiving was significantly (P < 0.01) influenced by maternal nutrient intake and was lower in the RMG (0.57) than in the NMG (0.85) group. For adolescent dams that maintained their pregnancies, liveweight gain during the first 95 days of gestation was significantly (P < 0.001) higher in the RMG compared with the NMG group (234 +/- 9.5 and 75 +/- 5.0 g day-1, respectively). Rapid maternal growth rates were associated with a significant reduction in both fetal and placental weights as determined when the animals were killed on day 95 of gestation (n = 3 per group) or at term. For the RMG (n = 8) and NMG (n = 11) groups, respectively, mean lamb birthweights at term were 2.74 +/- 0.25 and 4.34 +/- 0.27 kg (P < 0.001), while term placental weights were 263 +/- 16.8 and 438 +/- 44.6 g (P < 0.002). The number of fetal cotyledons per placenta and mean fetal cotyledon weight were significantly lower in RMG compared with NMG ewes (P < 0.05). Irrespective of treatment group, lamb birthweight was highly positively correlated with placental weight and both parameters were negatively correlated with maternal liveweight gain during the first 100 days of gestation. The incidence of non-infectious spontaneous abortion at 125 +/- 1.3 days of gestation was higher (P < 0.001) in the RMG (4 of 12) than in the NMG (1 of 12) group. Similarly, duration of gestation for those ewes delivering live young was shorter (P < 0.01) in the RMG compared with the NMG group (140 +/- 0.94 versus 143 +/- 0.28 days). Colostrum yield at parturition was positively related to placental weight and significantly lower (P < 0.001) in the RMG than in the NMG group (35 +/- 12.1 and 247 +/- 36.2 g, respectively). Neonatal survival rates at 72 h after parturition were reduced (P < 0.05) in the RMG (38%) compared with the NMG group (91%). These data suggest that in rapidly growing adolescent ewes, the established anabolic drive to maternal tissue synthesis is maintained at the expense of the gradually evolving nutrient requirements of the gravid uterus. This results in a major restriction in placental growth and a highly significant decrease in birthweight.

Animal Nutritional Physiological Phenomena↗

PubMed1995

Bacterial pneumonia in persons infected with the human immunodeficiency virus. Pulmonary Complications of HIV Infection Study Group.

BACKGROUND: Patients with human immunodeficiency virus (HIV) infection are at increased risk for bacterial pneumonia in addition to opportunistic infection. However, the risk factors for bacterial pneumonia and its incidence in this population are not well defined. METHODS: In a multicenter, prospective, observational study, we monitored 1130 HIV-positive and 167 HIV-negative participating adults for up to 64 months for pulmonary disease. The HIV-positive group comprised 814 homosexual or bisexual men, 261 injection-drug users, and 55 female partners of HIV-infected men. RESULTS: There were 237 episodes of bacterial pneumonia among the HIV-positive participants (rate, 5.5 per 100 person-years), as compared with 6 episodes among the HIV-negative participants (rate, 0.9 per 100 person-years; P < 0.001). The rate of bacterial pneumonia increased with decreasing CD4 lymphocyte counts (2.3, 6.8, and 10.8 episodes per 100 person-years in the strata with more than 500, 200 to 500, and fewer than 200 cells per cubic millimeter, respectively; P < or = 0.022 for each comparison). Injection-drug users had a higher rate of bacterial pneumonia than did homosexual or bisexual men or female partners. In the stratum with the fewest CD4 lymphocytes, cigarette smoking was associated with an increased rate of pneumonia. Mortality was almost four times higher among participants with an episode of pneumonia than among the others. Prophylaxis with trimethoprim-sulfamethoxazole was associated with a 67 percent reduction in confirmed episodes of bacterial pneumonia (P = 0.007). CONCLUSIONS: Bacterial pneumonia is more frequent in HIV-positive persons than in seronegative controls, and the risk is highest among those with CD4 lymphocyte counts below 200 per cubic millimeter and among injection-drug users.

AIDS-Related Opportunistic Infections↗

PubMed1995

Dietary fish oil supplementation alters leukocyte function and cytokine production in healthy women.

The effect of low-dose fish oil supplementation on cytokines and white cell function in women was investigated. Thirty-three healthy, nonsmoking women entered the double-blind study. For 4 weeks, 2.4 g of either fish oil (n = 16) or fish oil with vitamin E (n = 17) was added daily to the subjects' otherwise unchanged diets. Venous blood samples were taken at the onset of the trial, after the supplementation period, and again after a 9-week washout period. Plasma levels of platelet-derived growth factor and myeloperoxidase were measured using immunoassays. The intracellular peroxidase content of white blood cells was measured using a staining technique. Platelet-derived growth factor levels were significantly lowered after supplementation (P < or = .05). Intracellular peroxidase was increased (P < or = .01), and extracellular myeloperoxidase levels were lowered (P < or = .05). Taken together, these results suggest that the anti-inflammatory effect of fish oil may be due at least partly to alterations in white cell function and growth factor levels.

Adolescent↗

PubMed1995

Pulmonary function tests in HIV-infected patients without AIDS. Pulmonary Complications of HIV Infection Study Group.

To determine the prevalence, incidence, and types of lung diseases that occur in association with HIV infection, 1,353 subjects, including HIV-seropositive homosexual men, injection drug users, female sexual partners of HIV-positive men, and HIV-seronegative control subjects from the first two transmission categories were evaluated prospectively in a multicenter study. Patients with AIDS at the time of initial evaluation were excluded. One thousand two-hundred ninety-four subjects who had no AIDS-defining diagnosis within 3 mo of enrollment had measurements of FVC, FEV1 and DLCO at the time of enrollment. As a group, all subjects had mean values of FVC and FEV1 close to 100% predicted. Those with CD4 counts below 200/mm3 had slightly reduced DLCO compared with the others. Subjects with a history of HIV-associated symptoms (thrush, weight loss, herpes zoster) also had a reduced DLCO compared with those without symptoms. Injection drug users had reduced FVC, FEV1 and DLCO compared with homosexual men and female sexual partners of HIV-infected men, with DLCO more substantially reduced. Part of the reduction in DLCO in drug users was attributable to factors other than HIV infection, especially cigarette smoking and race. Using predicted values that take cigarette smoking into account, the prevalence of abnormality in DLCO was higher among injection drug users (33.3%) than among homosexual men (11.2%) and female sexual partners (12.7%). These results show that advanced HIV infection, characterized by CD4 count < 200/mm3 or HIV-associated symptoms, and factors unrelated to HIV infection, including race, cigarette smoking, and injection drug use, are all associated with reductions in DLCO measurements.

Bisexuality↗

PubMed1995

Conceptus interferon in uterine flush, endometrial concentrations of oxytocin receptors and prostaglandin F2 alpha release in vitro after transfer of conceptuses to ewes induced to ovulate at 28 days postpartum.

We examined the key events underlying maternal recognition of pregnancy and the prevention of luteolysis in early postpartum ewes by synchronously transferring single expanded blastocysts recovered from control ewes on day 11 of pregnancy into the uterus of either postpartum recipients that had been induced to ovulate 28 days after lambing (n = 12) or control recipients (n = 11). Conceptus development uterine flush interferon (oTP-1) concentrations, endometrial oxytocin receptor concentrations and endometrial prostaglandin F2 alpha (PGF2 alpha) release in vitro were determined 5 days later (corresponding to day 16 of the ovarian cycle). By this stage, both conceptus mass and oTP-1 content of total uterine flush in the eight postpartum recipients that remained pregnant were significantly lower (P < 0.01) than in the eight pregnant control ewes (524 +/- 116.6 versus 959 +/- 80.6 mg and 968 +/- 16.9 versus 1512 +/- 106.2 ng oTP-1 for postpartum and control recipients, respectively). These effects were independent of ovulation rate and daily peripheral progesterone concentrations after blastocyst transfer, which were similar between groups. Endometrial oxytocin receptor density was variable in both groups when they were killed, and was generally higher in pregnant postpartum than in control recipients, and was significantly different (P < 0.05) when the values for the transfer but not the contralateral uterine horns were compared. Similarly, basal and oxytocin-stimulated endometrial PGF2 alpha release during a 4 h incubation were higher (P < 0.01) in pregnant postpartum versus control recipients.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1994

Effect of post-ovulation nutritional status in ewes on early conceptus survival and growth in vivo and luteotrophic protein secretion in vitro.

Overfeeding during early pregnancy in ewes compromises pregnancy establishment and/or embryo survival. To determine whether high feed intakes after ovulation alter the secretory dialogue between the conceptus and the endometrium, 24 embryos (8-16-cell) from ewes fed maintenance rations were synchronously transferred in singleton on Day 3 of the cycle (oestrus, Day 0) into the uterus of ewes receiving a high or low plane of nutrition from Day 0 (n = 12 ewes per group). Embryo survival and conceptus growth were assessed on Day 16. At this time, pregnancy was maintained in 11 of 12 recipient ewes per group and conceptus mass was not influenced by nutritional plane (637 +/- 48 v. 583 +/- 72 mg for high and low groups respectively). Conceptus and endometrial tissues were cultured separately for a further 24 h in vitro in the presence of [3H]leucine. There was no quantitative difference between nutritional treatments in the incorporation of radiolabel into proteins synthesized and secreted by the conceptus or endometrium. Secretion of ovine trophoblast protein-1 was also similar in both groups. Peripheral progesterone concentrations were significantly (P < 0.05) lower throughout the luteal phase in recipient ewes on high v. low intakes after ovulation. This effect was independent of ovulation rate which was 3.1 +/- 0.40 and 2.6 +/- 0.25 corpora lutea for high and low groups respectively. A high plane of nutrition after ovulation did not influence embryo survival and development in vivo or luteotrophic protein secretion in vitro despite a reduction in peripheral progesterone concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)

Animal Nutritional Physiological Phenomena↗

PubMed1994

Routine analysis of induced sputum is not an effective strategy for screening persons infected with human immunodeficiency virus for Mycobacterium tuberculosis or Pneumocystis carinii. Pulmonary Complications of HIV Infection Study Group.

A prospective multicenter cohort study comprising 1,171 individuals who were seropositive for human immunodeficiency virus (HIV) but did not have AIDS at the time of enrollment and 182 HIV-seronegative controls, was studied by means of routine induced-sputum analysis in an attempt to detect occult tuberculosis or Pneumocystis carinii pneumonia. One occult case of tuberculosis was discovered upon the patient's enrollment (at baseline); none were discovered during follow-up. Two additional Mycobacterium tuberculosis isolates were recovered (one at baseline, one during follow-up) from subjects with symptoms or abnormalities evident on chest roentgenograms. Three specimens were false-positive (one for M. tuberculosis, two for P. carinii). Five pathogenic nontuberculous mycobacteria isolates were recovered during follow-up. Nonpathogenic, nontuberculous mycobacteria were recovered from 51 (4.6%) of 1,113 baseline specimens and 56 (3.7%) of 1,518 follow-up specimens, primarily at a center where the water supply was contaminated. We conclude that routine induced-sputum analysis is not an effective strategy for screening HIV-infected asymptomatic subjects for tuberculosis or P. carinii pneumonia before the onset of clinically recognizable disease activity.

Female↗

PubMed1994

Lymphocytic subpopulation profiles in bronchoalveolar lavage fluid and peripheral blood from tobacco and marijuana smokers.

The effect of heavy, habitual marijuana use compared with tobacco smoking on the composition of bronchoalveolar and peripheral blood lymphocytic phenotypes was examined. Bronchoalveolar lavage (BAL) and peripheral blood (PB) samples were taken from 14 nonsmokers (NS), 14 tobacco smokers (TS), 19 heavy, habitual marijuana smokers (MS), and 9 marijuana and tobacco smokers (MTS). In BAL fluid, marijuana use was associated with significantly higher alveolar macrophage concentrations, whereas tobacco smoking was associated with significantly higher alveolar macrophage, as well as higher bronchoalveolar lymphocyte and neutrophil concentrations. The bronchoalveolar T-lymphocytic phenotypic profiles of marijuana users differed from those of tobacco smokers. Tobacco, not marijuana, was found to have a significant effect toward lower percentages of bronchoalveolar CD4 cells, toward higher concentrations of bronchoalveolar CD8 cells, and toward lower bronchoalveolar CD4:CD8 ratios. Marijuana use had a significant effect toward lower percentages of bronchoalveolar CD8 cells. In peripheral blood, marijuana, but not tobacco, use was associated with significantly higher percentages of CD4 cells, lower percentages of CD8 cells, and higher CD4:CD8 ratios. These findings suggest that tobacco and marijuana have effects on bronchoalveolar and peripheral blood immunoregulatory T-lymphocytic subpopulations that differ in type or magnitude.

Adult↗