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Biomedical subjects

J Breuer

Publications and source records attributed to J Breuer.

At least 109 records · Page 6Linked to original sources
PubMed1995

Human immunodeficiency virus type 2 (HIV-2) env gene analysis: prediction of glycoprotein epitopes important for heterotypic neutralization and evidence for three genotype clusters within the HIV-2a subtype.

The env gene sequences of ten tissue-culture-adapted human immunodeficiency virus type 2 (HIV-2) isolates from West African patients were determined. Alignment and comparison of the gene sequences and putative translation products with database sequences revealed 11-29% diversity at the nucleotide level and 15-31% variation at the protein level. From analysis of glycoproteins of HIV-2 strains sensitive and resistant to neutralization by HIV-1 antisera, five regions were identified as putative targets for cross-neutralizing antibody. The HIV-2 equivalent of the HIV-1 V3 loop was not included in this number. However, three of the HIV-2 peptides aligned with regions identified as targets for broad neutralization of HIV-1 strains. These were the V2 and CD4-binding domains of gp120 and the Kennedy domain in gp41. Phylogenetic analysis of the env gene sequences, together with HIV-2 env gene sequences published in the Los Alamos database, support the identification of two distinct HIV-2 subtypes, HIV-2a and HIV-2b. The new sequences are located within the HIV-2a subtype and allow prediction of at least three genotypes, designated I-III. Some correlation of genotype with geographical origin of isolates was noted. Genotype I viruses originate from Guinea Bissau and group II viruses mainly originate from The Gambia. One isolate from Guinea Bissau, HIV-2CAM4, appears phylogenetically older than other viruses in the HIV-2a subtype. The possible implications of this in the light of epidemiological findings in Guinea Bissau are discussed.

Amino Acid Sequence↗
PubMed1995

[Improvement of perioperative hemodynamics and gas exchange by inhalation of nitric oxide in children with congenital cardiopulmonary defects].

OBJECTIVES: In critically ill infants and children before or after surgery for congenital cardiopulmonary disease it was evaluated whether continuous NO inhalation can reduce pulmonary artery pressure (PAP) and improve arterial oxygen saturation (SaO2). METHODS: All patients (n = 24; age 1 day-6.5 years) were intubated and artificially ventilated. They had either secondary pulmonary hypertension (n = 16), acute respiratory distress syndrome (n = 3), or reduced SaO2 (n = 5) due to pulmonary hypoperfusion. NO was introduced into the afferent limb of the ventilator circuit close to the endotracheal tube, while continuously measuring the inspired NO and O2 concentrations. The initially applied concentration of NO was 20 +/- 2.0 ppm. RESULTS: The hemodynamic condition and/or oxygen saturation was significantly improved by NO in 23 patients (95%). Mean PAP declined significantly from 45 +/- 7 to 28 +/- 3.7 mm Hg, while mean systemic arterial pressure remained constant (56 +/- 2.1 vs. 58 +/- 2.5 mm Hg). This was related to a selective reduction in pulmonary vascular resistance by 48 +/- 8.5%. SaO2 increased significantly (p < 0.05) from 83 +/- 2.5% to 93 +/- 1.5% due to a decreased intrapulmonary right-to-left shunt. NO therapy was applied with a median of 6 days (range 1.5-36 days). During NO inhalation methemoglobin concentration was significantly increased (0.77 +/- 0.05% vs. 1.46 +/- 0.15%), but neither was oxygen transport capacity affected, nor was any evidence for accumulation observed. Using a model ventilatory circuit, a nitric dioxide (NO2) formation of 1.14 +/- 0.11% of the applied NO concentration was measured, i.e. approximately 0.5 ppm NO2 at 40 ppm NO. This amount of NO2 in the inspired gas is well below toxicologically relevant concentrations. CONCLUSIONS: Low-dose NO inhalation selectively reduces PAP and improves SaO2 in children with congenital cardiopulmonary disease during perioperative intensive care. It is expected that the overall hemodynamic improvement is related to a reduced afterload of the subpulmonary ventricle without changes in coronary perfusion pressure, as is often observed with other vasodilators applied intravenously. We recommend an upper dose limit of 40 ppm NO for continuous NO inhalation to avoid possible toxicologically relevant NO2 concentrations.

Administration, Inhalation↗
PubMed1993

[Chronic metabolic alkalosis in a newborn infant caused by congenital chloride diarrhea].

The case of a female preterm infant (gestational age 36 weeks) is described, who presented with abdominal distension, diarrhoea, dehydration and metabolic alkalosis at the fifth day of life. After different diagnostic tests had been performed, congenital chloride diarrhoea was suspected and chloride supplementation was started. However, this diagnosis could not be confirmed, until the measurement of electrolytes in faeces had been improved. Then, we found the typically elevated fecal chloride concentration (130-153 mmol/l) which exceeded the sum of the fecal concentration of sodium (64-90 mmol/l) and potassium (28-35 mmol/l). The chloride supplementation was increased to 6 mmol/kg/d NaCl and 2 mmol/kg/d KCl. The most recent examination at the age of 1 year revealed the girl to be in good clinical condition, with normal growth and psychomotor-development and with no evidence of renal impairment.

Alkalosis↗
PubMed1992

[Hinman syndrome. Pronounced renal failure as a sequela of pseudo-neurogenic disorder of bladder emptying].

The case of an eight year old girl is presented who was seen because of secondary enuresis and recurrent urinary tract infection. Detailed examinations revealed urinary retention and sustained renal insufficiency (Creatinine clearance: 11 ml/min x 1.73 m2) due to a pseudo-neurogenic bladder. After improvement of renal function by continuous bladder drainage, bladder dysfunction was successfully treated by medication (Phenoxybenzamine, Baclofen), conventional physical therapy and biofeedback.

Acute Kidney Injury↗
PubMed1992

[Anomalous origin of the left coronary artery from the pulmonary artery. Variability of clinical aspects, echocardiography and angiography findings].

OBJECTIVES: Analysis of symptoms, diagnostical difficulties and follow-up in infants and children with anomalous origin of the left coronary artery from the pulmonary artery. METHODS: Retrospective study; 12 children between 3 weeks and 2 years old; time period: 1980-1991. RESULTS: Three infants were detected on routine examination because of a new cardiac murmur, the others presented with signs of cardiac failure. Cross sectional echocardiography and color Doppler flow mapping allowed to verify the suspected diagnosis. However, in one infant a false-negative cross sectional echocardiographic result was obtained. In this case nuclear magnetic resonance imaging was able to delineate the exact anatomy. Mean preoperative left ventricular ejection fraction: 33 +/- 4%; percentage of infants below the age of 6 months: 92%; surgery related mortality: 66%; mean follow-up of the remaining 4 patients being in good clinical condition: 2.9 +/- 1 years. CONCLUSIONS: 1. An anomalous origin of the left coronary artery should be included into the differential diagnosis when a new cardiac murmur is detected. 2. Possibility of false-negative echocardiographic results is emphasized. 3. With early symptoms and highly reduced left ventricular function, the mortality is still high.

Angiocardiography↗
PubMed1991

alpha-Peroxyachifolid and other new sensitizing sesquiterpene lactones from yarrow (Achillea millefolium L., Compositae).

Yarrow, Achillea millefolium L., is one of the commonest weeds of the Compositae family. Cases of allergic contact dermatitis have been described since 1899. Although 10 sesquiterpene lactones (SL) and 3 polyines have previously been identified, the sensitizers of yarrow have escaped detection. A reinvestigation of short ether extracts of yarrow revealed the presence of 5 unsaturated hitherto unknown guaianolides of peroxide character. The main SL, identified as a strong sensitizer in guinea pig sensitization experiments, was named alpha-peroxyachifolid. The minor SL also contribute marginally to the sensitizing capacity, while other known yarrow constituents like dehydromatricaria ester and pontica epoxide appear to play no role. A 5-year follow-up (1985-1990) of Compositae-sensitive patients showed that more than 50% reacted when tested with a short ether extract of yarrow. Exacerbation of the patch test sites by irradiation with UV light was never observed.

Animals↗
PubMed1991

[Peroxides as plant constituents. 8. Guaianolide-peroxides from yarrow,Achillea millefolium L., a soluble component causing yarrow dermatitis].

From the ether extract of the blossoms of yarrow, Achillea millefolium L., two guaianolides (1, 2) with a peroxide bridged cyclopentane ring and an alpha-methylene-gamma-butyrolactone structure have been isolated. For these compounds the names alpha-peroxyachifolid (1) and beta-peroxyisoachifolid (2) are proposed. 1 is responsible for the allergic contact dermatitis caused by yarrow.

Anti-Bacterial Agents↗
PubMed1990

[Validity of calculating oxygen saturation at rest and during exercise].

Oxygen saturation calculated with the formulae proposed by Heck, Kelman, Lutz, Marsoner, Severing-haus and Siggaard-Andersen, was compared with oxygen saturation measured photometrically. An analysis of 1350 peripheral venous, mixed venous and arterial blood samples obtained during bicycle ergometry revealed that only the calculations using the Kelman, Siggaard-Andersen and Severing-haus formulae had adequate validity and reliability over a wide measuring range. If, however, the oxygen saturation figures are to be used for further calculations, direct measurement should be given preference to avoid errors (for example, in shunt calculation).

Exercise Test↗
PubMed1989

Oxygen saturation calculation procedures: a critical analysis of six equations for the determination of oxygen saturation.

Photometrically measured values of O2-saturation (SO2) were compared with SO2 predictions on the basis of the equations proposed by Heck, Kelman, Lutz, Marsoner, Severinghaus, and Siggaard-Andersen on 1350 occasions. Capillary, venous and mixed venous blood samples from 23 healthy subjects and 30 patients, suffering from cardio-pulmonary diseases were analyzed at rest, during exhaustion, limited exercise and during the recovery phase of ergometric tests. Overall the best agreements with the measured values were found for the equations of Kelman, Severinghaus and Siggaard-Andersen. The results of Heck's, Lutz', and Marsoner's predictions were in reasonable agreement with the measured SO2 only under special physiological conditions. No calculation mode can be performed with constant accuracy and reliability when covering a wide range of acid-base values. If SO2 values are used for further calculations, e.g. for determination of cardiac output, measured values are preferred.

Adult↗
PubMed1989

Excretion of hippuric acid during sodium benzoate therapy in patients with hyperglycinaemia or hyperammonaemia.

In patients with non-ketotic hyperglycinaemia and two patients with urea cycle disorders treated with varying doses of sodium benzoate there was linear correlation between intake of benzoate and excretion of hippurate. Patients with non-ketotic hyperglycinaemia excreted significantly more benzoate in the form of hippurate than patients with urea cycle disorders (74 +/- 7.0 vs 41 +/- 3.6%). The plasma concentration of glycine decreased following benzoate treatment only in the patients with non-ketotic hyperglycinaemia. The observed difference between the two groups in the excretion of hippurate seems to support the concept that glycine availability may be limiting in benzoate therapy for some patients.

Amino Acid Metabolism, Inborn Errors↗