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Biomedical subjects

H Glass

Publications and source records attributed to H Glass.

At least 19 recordsLinked to original sources
PubMed2000

Primary health care: then and now.

The term primary health care is now entrenched in our minds and our actions. A health for all by the year 2000 strategy is being examined to determine what has been achieved and what has not. All countries and most professions, including nursing, are scrutinizing the progress they have made towards achieving PHC. It is my intention, in this discourse, to move from an historical view to present-day concerns as they relate to the achievement of PHC. It will be impossible to do more than mention many of the latter, but I hope to set the stage for the articles that follow in this issue of the Journal.

Canada↗
PubMed1997

Effects of dry season dormancy on oxygen uptake, heart rate, and blood pressures in the toad, Bufo paracnemis.

The cardiodynamic consequences of dry season dormancy in ectothermic vertebrates is not well known. Our hypothesis was that dormancy would reduce cardiac activity. We therefore determined oxygen uptake and cardiovascular function in aestivating toads, Bufo paracnemis, native to São Paulo State, Brazil. Specimens were collected and kept in the laboratory under controlled temperature and light regimes. We compared oxygen uptake, heart rate, blood pressure, rate-pressure product (RPP), and blood gases in toads during aestivation (dry winter season) and their early active season (spring). Oxygen uptake of winter toads at 25 degrees C was considerably lower than that of spring toads (winter: 24.0 +/- 1.8 ml/(kgh); early spring: 44.4 +/- 5.1 ml/(kgh); mean +/- SE; same in the following). A seasonal dichotomy was also observed at 15 degrees C although the differences was less pronounced (15.8 +/- 1.8 ml/(kgh) winter; 23 +/- 2.1 ml/(kgh) early spring). Chronic arterial cannulation permitted measurements of cardiodynamic variables without any undesired change in VO2. Heart rates of winter toads were significantly lower than those of early spring animals at both experimental temperatures (25 degrees C: winter 25 +/- 1.4 beats/min.; early spring: 35.2 +/- 5.1 beats/min. 15 degrees C: winter 15, 4 +/- 1.8 beats/min.; early spring: 23.9 +/- 2.1 beats/min). Systemic, diastolic and mean arterial pressures decreased slightly but not significantly during aestivation. We conclude that: (1) Bufo paracnemis downregulates metabolic rate during the dry season and (2) heart rate is also downregulated with little change of blood pressure. While the energetics of these responses are probably beneficial for survival during aestivation, the underlying biochemical mechanisms remain obscure.

Animals↗
PubMed1997

Correlations between ANP concentrations in atria, plasma and cerebral structures and sodium chloride preference in Wistar rats.

We determined whether ANP (atrial natriuretic peptide) concentrations, measured by radioimmunoassay, in the ANPergic cerebral regions involved in regulation of sodium intake and excretion and pituitary glad correlated with differences in sodium preference among 40 Wistar male rats (180-220 g). Sodium preference was measured as mean spontaneous ingestion of 1.5% NaCl solution during a test period of 12 days. The relevant tissues included the olfactory bulb (OB), the posterior and anterior lobes of the pituitary gland (PP and AP, respectively), the median eminence (ME), the medial basal hypothalamus (MBH), and the region anteroventral to the third ventricle (AV3V). We also measured ANP content in the right (RA) and left atrium (LA) and plasma. The concentrations of ANP in the OB and the AP were correlated with sodium ingestion during the preceding 24 h, since an increase of ANP in these structures was associated with a reduced ingestion and vice-versa (OB: r = -0.3649, P < 0.05; AP: r = -0.3291, P < 0.05). Moreover, the AP exhibited a correlation between ANP concentration and mean NaCl intake (r = -0.4165, P < 0.05), but this was not the case for the OB (r = 0.2422). This suggests that differences in sodium preference among individual male rats can be related to variations of AP ANP level. Earlier studies indicated that the OB is involved in the control of NaCl ingestion. Our data suggests that the OB ANP level may play a role mainly in day-to-day variations of sodium ingestion in the individual rat.

Animals↗
PubMed1996

Sodium balance of hyper- and hypo-natriophilic rats under basal conditions and during sodium deprivation.

Sodium and water balance was determined in two strains of Wistar rats selectively bred for high (hypernatriophilic, HR) or low salt preference (hyponatriophilic, HO) under basal conditions and during sodium deprivation. Male rats from each stain were selected for an average ingestion of 1.5% NaCl solution of more than (HR) or less than (HO) 4 ml 100 g body weight (-1) day (-1), during a 10-day period. HR rats (N = 17) presented markedly higher sodium intake under basal conditions (2.983 +/- 0.316 mEq 100 g body weight (-1) day (-1)) than HO rats (N = 12; 0.406 +/- 0.076 mEq 100 g body weight (-1) day (-1); Mann-Whitney test, P < 0.01). Water (HR: 8.6 +/- 0.57; HO: 7.7 +/- 0.32 ml 100 g body weight (-1) day (-1)) and sodium balances (HR: 0.936 +/- 0.153; HO: 0.873 +/- 0.078 mEq 100 g body weight (-1) day (-1)) were similar in both strains, despite a higher sodium and total fluid (HR: 16.3 +/- 1.06; HO: 10.8 +/- 0.49 ml 100 g body weight (-1) day (-1); P < 0.01) ingestion in HR rats. During sodium deprivation HR rats (N = 13) exhibited a sodium balance similar to that of HO rats (N = 13) (HR: -0.159 +/- 0.011; HO: -0.129 +/- 0.019 mEq 100 g body weight (-1) day (-1)), and, in addition, an adequate suppression of natriuresis (HR: 0.049 +/- 0.011; HO: 0.026 +/- 0.004 mEq 100 g body weight (-1) day (-1)). These data show that HR rats present hypernatriophilia as a primary trait, since their sodium-conserving mechanisms are intact. Therefore, these rats provide an adequate model to study factors that determine innate sodium preference.

Animals↗
PubMed1980

Isolation, culture and characterization of epithelial cells derived from rat ventral prostate.

Epithelial-cell enriched primary cultures have been established from rat ventral prostate (RVP). Minced ventral prostates were dissociated with 0.5% collagenase in F12K tissue culture medium containing 1% fetal bovine serum. This treatment resulted in the gradual removal of stromal elements from the base of the epithelial cells. After 60 minutes of digestion the aggregates of epithelial cells were washed and plated at high density in F12K plus 10% horse serum. After 48 hours in vitro the unattached cells were removed from the culture dishes, washed, and reinoculated into new culture vessels containing fresh medium. After 96 hours in vitro, the aggregates had attached to the culture vessels and spread out to yield discrete patches of epithelial cells. By 144 hours in vitro the patches of cells had grown and coalesced to form a semi-confluent monolayer of epithelial cells. Ultrastructrual examination of these cultures indicated that adjacent cells were joined by desmosomes and tight junctions and had formed "lumen-like structures" into which projected microvilli. In addition, the cells contained secretory granules and tonofilaments, giving them a morphological appearance similar to prostate epithelial cells in the intact organ. The primary cultures also retained histochemical activities for acid phosphatase, beta-glucuronidase, and succinic dehydrogenase that were similar to the intact organ.

Animals↗
PubMed1978

Immunohistochemical localisation of ecdysteroids in the follicular epithelium of locust oocytes.

Frozen sections of growing terminal follicles of the locust ovary were incubated with an ecdysteroid-specific rabbit antibody and the bound antibody visualised by the use of FITC-labelled goat-anti-rabbit antiserum. A bright fluorescence was seen in the cytoplasm of the follicle cells in terminal follicles with a length between 4.0 and 6.0 mm with a maximum intensity at 5.5 mm, indicating the presence of ecdysteroids in these cells in this particular developmental stage.

Animals↗
PubMed1975

Clinical application of regional lung function studies in infants and small children using 13N.

A technique is described for the investigation of regional lung function in infants and children using 13N and a gamma camera. Boluses of isotopic gas are inhaled and perfused while the lung fields are scanned. The child is lightly sedated and breathes normally throughout. Regional function is assessed in terms of the distribution of gas and blood, and the balance between ventilation and perfusion is estimated by comparing an index of the ventilation per unit volume of ventilated lung with that of perfused lung. The use of the method in 8 infants and children with different clinical problems is described to show its application. The method is capable of defining the severity and localization of any abnormality and may also be useful in showing normal function in suspect areas.

Child, Preschool↗