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Biomedical subjects

G Grossmann

Publications and source records attributed to G Grossmann.

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

Diastolic ventricular function in type 1 diabetic patients: a study using Doppler echocardiography.

The transmitral flow velocity pattern of 28 Type 1 diabetic patients and 39 age-matched healthy control subjects was studied for determination of left ventricular diastolic function. No patient had systemic hypertension, congestive heart failure, or ischaemic heart disease by clinical or electrocardiographic criteria. Echocardiographic measures of systolic ventricular function were within normal range in all subjects. The ratio of early to late transmitral peak flow velocity (ve/va) was significantly decreased in the diabetic patients (1.3 +/- 0.1 (+/- SE) vs 1.6 +/- 0.1, p less than 0.05), while other Doppler derived variables did not show any significant difference. No correlation of ve/va with duration of diabetes was found (r = -0.27), but it correlated with age in both groups (both r = -0.40, p less than 0.05). Furthermore, a significant correlation was found between ve/va and heart rate (r = -0.55 for diabetic patients, p less than 0.01; r = -0.58 for control subjects, p less than 0.01). After matching for heart rate (24 diabetic patients and 24 control subjects) no significant decrease of ve/va was observed in the diabetic group.

Adult↗
PubMed1991

Partial ureteric obstruction in the pubescent rat. II. Long-term effects on the renal morphology.

Partial obstruction of one ureter was created in pubescent rats (6 weeks of age) and its effects were studied after 1-15 weeks. Within 1 week, a considerable hydronephrosis and a moderate decrease in the number of glomeruli had developed. These changes did not progress with time. The renal parenchymal weight never became affected and the microstructure was only slightly influenced. Thus, the effects of a partial ureteric obstruction on renal morphology seem to be comparatively mild in this age group, and even less prominent than the modest changes previously observed in rats obstructed since the neonatal period. The reasons for this age difference and for the reduction in glomerular number are discussed.

Animals↗
PubMed1991

Inactivation of exogenous surfactant by pulmonary edema fluid.

Modified natural porcine surfactant was mixed with edema fluid sampled from the airways of hyperoxia-exposed adult rabbits. By varying the concentration of surfactant lipids (10, 25, and 50 mg/mL) and edema fluid proteins (0-280 mg/mL), we obtained a series of preparations with protein to surfactant lipid weight ratios ranging from 0 to 11.2. The surfactant activity of these various mixtures was analyzed with a pulsating bubble (at a lipid concentration of 10 mg/mL) or in experiments on immature newborn rabbits (at lipid concentrations of 25 or 50 mg/mL). For the latter purpose, animals were delivered at a gestational age of 27 d and ventilated with a standardized sequence of insufflation pressures after receiving 0.1 mL of the surfactant-edema sample into the airways at birth. Nearly complete in vitro inhibition of surfactant (markedly delayed film adsorption and a minimum surface tension of 23 mN/m during pulsation) was observed at a protein to surfactant lipid ratio of 4.5. Under in vivo conditions, nearly complete surfactant inhibition (tidal volumes reduced to less than 20% of the values for littermates ventilated with the same pressure after receiving surfactant without admixture of edema fluid) was documented at a protein to surfactant lipid ratio of 11.2. Our data suggest that the functional properties of an immature neonatal lung, in which serum proteins tend to leak into the airspaces after the onset of ventilation, depend on the stoichiometric relation between surfactant lipids and inhibitory proteins in the lung liquid.

Animals↗
PubMed1991

Experimental neonatal respiratory failure induced by a monoclonal antibody to the hydrophobic surfactant-associated protein SP-B.

The present experiments were designed to test whether selective blocking of the surfactant-associated hydrophobic polypeptide SP-B (8.7 kD) would interfere with lung function during neonatal adaptation. A MAb to porcine SP-B was produced by hybridoma cell line (8B5E); this antibody cross-reacts with rabbit SP-B. Six mg of MAb to SP-B, dissolved in 0.2 mL of saline, was instilled into the airways of near-term newborn rabbits (gestational age 29 d), before the onset of ventilation. Control animals received the same amount of nonspecific rabbit IgG in saline, or were untreated. The animals were ventilated for 120 min with a standardized tidal volume (10 mL/kg). The specific antibody caused a prominent, immediate decrease in lung-thorax compliance, associated with acute inflammatory and exudative lung lesions including hyaline membranes. IgG alone had no such effects. Our data suggest that the MAb to SP-B inhibits surfactant function in the neonatal period by blocking one of the mechanisms responsible for fast adsorption of the surfactant phospholipids to the alveolar air-liquid interface. In addition, an acute inflammatory reaction is probably triggered in the lung parenchyma by the immune reaction.

Animals↗
PubMed1991

Application of a new ventilator-multi-plethysmograph system for testing efficacy of surfactant replacement in newborn rabbits.

We applied a new ventilator-multi-plethysmograph system to evaluate the effect of surfactant replacement in newborn rabbits under well controlled, nearly physiological conditions characterized by normal ECG and adequate PCO2 in right ventricular heart blood obtained at the end of the experiment. Up to 10 animals were ventilated in parallel with a pressure-constant common respirator system. Using a working pressure of 4.9 kPa (50 cmH2O), we could adjust the pressure delivered to each animal within the range of 0.49-4.4 kPa (5-45 cmH2O), by changing the length of an open high-resistance tube constituting the outflow limb of the connection between the common ventilator tube and the tracheal cannula. Immature newborn animals obtained after 27.5 days gestation and ventilated for 30 min with a tidal volume of 8-10 ml.kg-1 had a mean +/- SD lung-thorax compliance of 4.2 +/- 1.1 ml.kPa-1.kg-1 (0.41 +/- 0.11 ml.cmH2O-1.kg-1) and PCO2 of 8.5 +/- 1.9 kPa. In littermates treated at birth with a large dose of natural surfactant (Curosurf, 200 mg.kg-1, compliance increased to 6.0 +/- 1.0 ml.kPa-1.kg-1 (0.68 +/- 0.10 ml.cmH2O-1.kg-1) (p less than 0.01) and PCO2 decreased to 6.9 +/- 1.2 kPa (p less than 0.01). Near-term animals, obtained at 30 days gestation and ventilated under similar conditions had a compliance of 7.2 +/- 0.9 ml.kPa-1.kg-1 (0.71 +/- 0.09 ml.cmH2O-1.kg-1) and PCO2 of 6.4 (1.2) kPa. Administration of surfactant (same dose as above) to these mature animals at birth had no adverse effects.

Animals↗
PubMed1990

[Relationship of the left ventricular wall thickness to the degree of late microvascular complications in diabetes mellitus type I].

Left-ventricular wall thickness, measured by echocardiography, was determined in 111 normotensive diabetics (63 men and 48 women; mean age 26 +/- 9 years; diabetes duration 13.5 +/- 6.2 years) and 91 comparable control subjects. The interventricular septum was significantly thicker in diabetics than in controls: systolic 13.3 +/- 2.3 mm, diastolic 9.2 +/- 2.2 mm vs. systolic 12.5 +/- 2.1 mm and diastolic 8.9 +/- 1.7 mm (P less than 0.05). Posterior wall thickness measurements were: systolic 15.8 +/- 2.2 mm vs 14.6 +/- 2.0 mm (P less than 0.001), diastolic 9.5 +/- 1.8 mm vs 8.4 +/- 1.3 mm (P less than 0.01). Left-ventricular wall thickness increased stepwise with increasing severity of microvascular complications (retinopathy, nephropathy, neuropathy). There was a moderately close correlation between blood pressure values and the degree of microvascular complications (r = 0.49, P less than 0.01). These correlations indicate that increases in wall thickness are diabetes specific, but may be influenced by the level of blood pressure.

Adult↗
PubMed1990

Lack of tolerance after chronic administration of controlled-release isosorbide-5-mononitrate. Interaction of nitrate and gallopamil.

The effect of a controlled-release formulation of isosorbide-5-mononitrate (IS-5-MN) was studied in patients with coronary heart disease (CHD), with the aim of comparing the acute effect with that after chronic administration on parameters of ischemia. To determine whether any tolerance developed, several aspects of ischemia were observed: ECG signs, clinical parameters, and left ventricular function. Fifteen patients with angiographically proven CHD were examined with 12-lead exercise ECG before, 2 h and 4 h after the first dose and after 10 days of therapy with 60 mg IS-5-MN (Coleb-Duriles) once daily. After 7 days, three radionuclide ventriculographies were performed: control, 2 h after nitrate and 2 h after 75 mg gallopamil. Plasma concentrations of IS-5-MN were measured before every exercise test. The results showed a reduction of total ST-segment depression from 0.59 mV to 0.29 mV after 2 h (NS) and 4 h (P less than 0.05) on the 1st day and from 0.48 mV to 0.32 mV (P less than 0.05) and 0.31 mV (NS) after 10 days. The severity of angina pectoris was diminished by about 50%. The effect on exercise duration and time to ST-segment depression by more than 0.1 mV remained unchanged after 10 days, whereas the effect on blood pressure, heart rate and time to onset of angina was attenuated. The mean decrease in ejection fraction (EF) from rest to exercise was reduced from--5.9% to -1.9% (P less than 0.05) after nitrate, while an increase of +1.4% was seen after gallopamil (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Passive expiratory flow-volume recordings in immature newborn rabbits. Effect of surfactant replacement on the time constant of the respiratory system.

Immature newborn rabbits with a gestational age of 27 days were paralyzed and kept in body plethysmographs. They were ventilated for 10 min with a tidal volume of approximately 10 ml/kg, with or without previous surfactant treatment via the airways. Tidal volumes and flow were recorded with a pneumotachograph connected to the body plethysmograph, and the expiratory time constant of the respiratory system (trs) was determined from flow-volume diagrams. The values of trs after 10 min were significantly higher in surfactant-treated animals than in controls (50 +/- 7 vs. 23 +/- 4 ms; p less than 0.002), indicating stabilization of the alveoli. There was also a close correlation between trs and the compliance values calculated from tidal volumes and ventilator pressure (r = 0.80; p less than 0.001), as well as between trs and the alveolar volume density in histological lung sections, determined by automated image analysis (r = 0.71; p less than 0.001).

Animals↗
PubMed1990

[Street traffic noise and stress experience].

Interpreting a sociological study in the city of Erfurt the results of a written interrogation of noise annoyance of a representative random sample of inhabitants are shown and selected characteristics both of the annoyed and the nonannoyed inhabitants are compared. From noise level measurements a proposal for a traffic noise threshold limit has been derived that corresponds to the requirement for calm. Moreover, moderators have been investigated which interfere with the degree of annoyance; health complaints of both groups of the interrogated individuals were compared. It could be shown, that a written interrogation of inhabitants of a territory is able to deliver sufficiently exact information concerning noise annoyance.

Germany, East↗
PubMed1990

[New aspects of the traffic noise problem in the inner city area].

As a result of a sociological-oriented noise study in the city of Erfurt specific intracity noise problems are analysed via their effects. The authors deal with the expectation of calm of people living in different areas of the city, with the relevance of effect of the two usual evaluation levels Leq and Lmax for noise by running traffic, with noise decrease by sound attenuation improvements, and with the subjective and objective evaluation of an industrial front ventilation element. Moreover, the effects of traffic noise on inhabitants before and after significant traffic reduction are shown.

Automobiles↗
PubMed1989

[Stress testing of long-term type I diabetic patients with radionuclide ventriculography].

Left ventricular function was assessed by means of radionuclide ventriculography in 42 patients with long-standing (13 +/- 5 yrs) insulin-dependent diabetes mellitus and in eleven healthy age matched control subjects. Only diabetics were included in the study without diabetes related cardiac risk factors such as hypertension and CAD in order to evaluate diabetes specific changes of cardiac function. No differences were seen between diabetics and controls concerning heart rate and functional parameters of left ventricle in systole and diastole. The rapid filling period was not prolonged. According to our radionuclide data there is no evidence of diabetes related impairment of ventricular function in young patients with long-standing type-1-diabetes mellitus.

Adult↗
PubMed1989

Inhibition of exogenous surfactant in ventilated immature newborn rabbits.

Immature newborn rabbits were treated at birth by tracheal instillation of porcine surfactant (100 microliters, phospholipid concentration 80 mg.ml-1), to which [14C]dipalmitoylphosphatidylcholine had been added as a marker. They were kept in a body plethysmograph/pneumotachygraph system at 37 degrees C. During a 120 min period of artificial ventilation with a peak insufflation pressure of 20 cm H2O, there was a gradual decrease in tidal volumes (36%.h-1). This decrease was correlated to an elevation of minimum surface tension (r = 0.81; P less than 0.01) and to a prolongation of the adsorption rate (r = 0.80; P less than 0.01) of surfactant recovered by lung lavage from the same animals. There was also correlations between duration of ventilation and minimum surface tension (r = 0.56; P less than 0.01), and between duration of ventilation and adsorption rate (r = 0.73; P less than 0.01). The surface properties of phospholipids extracted from the lavage fluid were similar to those of the original surfactant preparation. Our data suggest that, in immature newborn rabbits subjected to artificial ventilation, exogenous surfactant may become inactivated, probably due to protein leakage into the airspaces.

Animals↗
PubMed1989

Genomic footprinting in mammalian cells with ultraviolet light.

A simple and accurate genomic primer extension method has been developed to detect ultraviolet footprinting patterns of regulatory protein-DNA interactions in mammalian genomic DNA. The technique can also detect footprinting or sequencing patterns introduced into genomic DNA by other methods. Purified genomic DNA, containing either damaged bases or strand breaks introduced by footprinting or sequencing reactions, is first cut with a convenient restriction enzyme to reduce its molecular weight. A highly radioactive single-stranded DNA primer that is complementary to a region of genomic DNA whose sequence or footprint one wishes to examine is then mixed with 50 micrograms of restriction enzyme-cut genomic DNA. The primer is approximately 100 bases long and contains 85 radioactive phosphates, each of specific activity 3000 Ci/mmol (1 Ci = 37 GBq). A simple and fast method for preparing such primers is described. Following brief heat denaturation at 100 degrees C, the solution of genomic DNA and primer is cooled to 74 degrees C and a second solution containing Taq polymerase (Thermus aquaticus DNA polymerase) and the four deoxynucleotide triphosphates is added to initiate primer extension of genomic DNA. Taq polymerase extends genomic hybridized primer until its polymerization reaction is terminated either by a damaged base or strand break in genomic DNA or by the addition of dideoxynucleotide triphosphates in the polymerization reaction. The concurrent primer hybridization-extension reaction is terminated after 5 hr and unhybridized primer is digested away by mung bean nuclease. Primer-extended genomic DNA is then denatured and electrophoresed on a polyacrylamide sequencing gel, and radioactive primer extension products are revealed by autoradiography. By using this method we demonstrate that it is possible to footprint with ultraviolet light, in intact monkey cells, regulatory protein--DNA interactions along a single copy of a simian virus 40 viral genome integrated into the monkey genome.

Animals↗
PubMed1989

Vascular to alveolar leak of iron dextran (120 kD) in the immature ventilated rabbit lung.

Rabbit fetuses were delivered by hysterotomy on day 27 or 28 of gestation. Immediately after birth, the animals were tracheotomized and received by intravenous injection 0.2 mu Ci radiolabeled albumin and 11 mg iron dextran in 0.2 ml saline. The newborn rabbits then were ventilated artificially with a tidal vol of 12 ml/kg for 5-20 min. One group of nonventilated animals served as controls. At the end of the experiment, one lung was lavaged via the airways and the other was fixed for histologic examination. The recovery of labeled albumin and iron dextran in the lavage fluid was quantified. Iron dextran complexes were easily identified in the lung sections by staining with Prussian blue. Iron dextran accumulated in the airspaces of animals delivered on day 27 (about 4% of the injected dose during 10-20 min of ventilation). The albumin leakage was slightly higher than that of the dextran, a result consistent with different mol wt of the markers. The vol density of leaking alveoli in histologic sections increased with time, from 0 at birth to a mean value of 0.36 after 20 min of ventilation. The leakage starts as a focal event, gradually involving more and more terminal airspaces. In the histologic sections, there was no indication of a significant leakage at the bronchiolar level, although the epithelium of terminal and preterminal airways was clearly injured in all ventilated animals.

Albumins↗