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Biomedical subjects

J Mayer

Publications and source records attributed to J Mayer.

At least 271 records · Page 15Linked to original sources
PubMed1986

Sleep apnea and pulmonary hypertension.

The pulmonary artery pressure values of 65 patients with sleep apnea syndrome were measured at rest and during ergometer exercise up to 100 W. Pulmonary hypertension at rest was found in 13, and during exercise in 31 more patients. Only 8 patients with pathological pressure findings suffered from pulmonary hypertension in combination with a pulmonary or cardiac disease. In the other 36 patients, no indication of a primary cause of pulmonary hypertension apart from sleep apnea syndrome could be found. Out of the 65 patients, 11 with a finding of more than 20 apnea episodes per hour's sleep underwent polysomnographic recordings in the sleep laboratory. The hemodynamic parameters were continuously measured. All 11 patients had a finding of severe sleep apnea with more than 300 apnea episodes during the night of recording. In 6 patients, the appearance of apnea episodes was accompanied by only moderate changes in pulmonary artery pressure. In 5 patients, there were critical increases in pulmonary artery pressure, which went along with increases in cardiac output and in pulmonary capillary wedge pressure. Increases in pulmonary vascular resistance were established in 3 out of these 5 patients, and a slight decrease in 2. The mechanism of hypoxic vasoconstriction of the pulmonary arteries may account for the pressure increases in 3 of our patients, but fails to explain the findings in the other 2 patients. Nocturnal changes in pulmonary artery pressure in patients with sleep apnea may therefore have different causes. Pulmonary hypertension constitutes a severe complication in patients with sleep apnea.(ABSTRACT TRUNCATED AT 250 WORDS)

Airway Resistance↗
PubMed1986

Plasma proteinases, proteinase inhibitors and other selective plasma proteins following aortofemoral bypass operation.

Monitoring of plasma proteinases, proteinase inhibitors and other selective plasma proteins was evaluated in patients undergoing Y-graft aortofemoral bypass operation. Fast-reacting acute-phase proteins (C-reactive protein, antichymotrypsin, alpha 1-acid glycoprotein) and slow-reacting proteins (haptoglobin, alpha 1-antitrypsin) increased significantly 48-120 h after operation. By contrast, no significant increase was found between plasma ceruloplasmin levels before clamping and after declamping. Activity and concentration of alpha 2-macroglobulin decreased postoperatively and remained significantly lowered throughout the observation period. Plasma levels of granulocyte elastase were elevated significantly 1 h after declamping, whereas trypsin-binding capacity decreased immediately after the release of the clamp. Aprotinin pretreatment caused higher trypsin-binding capacity of the plasma, significantly lower 'unspecific' proteolytic (azocasein-hydrolyzing) activity and significantly lower non-TCA precipitable low molecular weight plasma protein concentration. Our results confirm the data of several authors that monitoring of plasma proteinases, proteinase inhibitors and other selective plasma proteins may be helpful in evaluating surgical patients postoperatively.

Adult↗
PubMed1986

Intravenous paraldehyde for seizure control in newborn infants.

We studied 14 newborn infants with seizures after birth asphyxia or other causes. Paraldehyde was given as a 200 mg/kg IV bolus followed by an infusion of 16 mg/kg/h (10 cases), or as a 400 mg/kg bolus (4 cases). Serum concentrations of paraldehyde were higher in periods of adequate seizure control than in periods of little or no response. Paraldehyde serum concentrations above 10 mg/dl were associated with anticonvulsant effects and were achieved in most neonates with a 2-hour infusion of 200 mg/kg/h. If there is no effect, serum concentrations are probably below 10 mg/dl and an additional 200 mg/kg can be given safely over 1 hour.

Female↗
PubMed1986

[Pulse oximetry as a continuous, noninvasive monitoring procedure. Comparison of 2 instruments].

Pulse oximetry allows continuous registration of the arterial oxygen saturation by using the light absorption in a wave range between 600 and 1,000 nm. In addition the peripheral pulse is determined by a plethysmographic method. Two new devices, the Biox III pulse oximeter and the Nellcor pulse oximeter were compared for the following three items: 1. The accuracy in comparison with a simultaneously determined arterial oxygen saturation. Concerning the Biox III instrument, the correlation coefficient resulted in r = 0.90, for the Nellcor device in r = 0.92. 2. The onset time for registering a suddenly appearing hypoxia: For the Biox III oximeter we found a time lag between 6 and 42 s (median 21 s), for the Nellcor Oximeter between 12-39 s (median 21 s). 3. The pulse frequency corresponded very well with the simultaneously registered heart rate of the ECG. Our results indicate that pulse oximetry--a continuous and noninvasive method--is a reliable monitor for oxygen saturation, and provides trend informations about circulation, both of which are particularly appropriate for patients breathing spontaneously.

Adult↗
PubMed1985

Prevalence of sleep apnea in healthy industrial workers.

The present study reports on polysomnographic findings of sleep apnea syndrome in a representative sample of otherwise healthy middle-aged blue collar workers (age 45.7 +/- 8.5) with normal to borderline blood pressure (systolic 135.5 +/- 16.1; diastolic: 88.3 +/- 10.2), mild overweight (Broca 114.9 +/- 14.7) and with reported nocturnal sleep disturbances. The prevalence of sleep apnea in this sample (N = 20 out of a total of 78 workers with reported sleep disturbances) is 40%. Mean frequency of apnoeic episodes during night was 97.6 +/- 42.7 in the apnea-positive group as compared to 27.1 +/- 19.9 in the apnea-negative group (T = 5.0; p less than 0.0001), with an apnea index of 13.3 +/- 6.2 as compared to 3.5 +/- 2.3 (T = 7.2, p less than 0.0001). Left ventricular hypertrophy (mean diameter of end diastolic left ventricle: 64.0 +/- 9.5 mm) was found in individuals with apnea although manifest hypertension was absent in most individuals.

Adult↗
PubMed1985

Male factor evaluation in in vitro fertilization: Norfolk experience.

Thirty-three patients from the in vitro fertilization (IVF) program at Norfolk are critically reviewed. A battery of tests was designed and an endocrine investigation was carried out on these patients. The fertilization rate for preovulatory oocytes was lower than in the normal male population (39.6% versus 88.6%). When total concentration of sperm with rapidly progressive motility was less than 6 X 10(5), to fertilize several eggs together the fertilization rate was zero. No fertilization was obtained when the number of sperm with rapidly progressive motility recovered after the separation was less than 1.5 X 10(6). The hamster zona-free oocyte penetration test correlated well with the human IVF system. The other parameters investigated did not show good correlation. When fertilization was achieved, the results of the IVF procedure in the series reviewed rendered a 30.8% pregnancy rate per transfer in 26 transfers. Fifty percent of the pregnancies were normal (either ongoing or delivered). Thirty-seven percent were preclinical miscarriages, and 12.5% were clinical abortions. In the abnormal male population, higher concentrations of sperm per egg should be used for insemination for achievement of optimum fertilization rates. Once fertilization is obtained, the results do not differ substantially from the IVF population at large.

Animals↗
PubMed1985

[Inverse corneal incision in cataract surgery].

In a prospective study of 100 cases of cataract surgery, astigmatism surgically induced by the reversed corneal incision technique was evaluated. There was a tendency towards with-the-rule and oblique astigmatism in the early post-operative period, but the final distribution of cases was similar to the preoperative distribution. The sutures could be left in place in about one third of the cases.

Astigmatism↗
PubMed1985

[Frequency of sensitization to D. pteronyssinus or D. farinae in children with perennial bronchial asthma].

Bronchial sensitization against house dust mites (dermatophagoides farinae, dermatophagoides pteronyssinus) was investigated in 48 children. The therapeutic effect of hyposensitization and removal of house dust mite allergen was evaluated. The diagnosis was established by skin-prick-test, RAST and bronchial provocation. The bronchial provocation test was carried out by a whole body plethysmograph with breath by breath registration of the airway resistance. We found a bronchial reaction against both mites in 70% of the children; 18% showed bronchial reaction only against d. farinae, 10% only against d. pteronyssinus. There was a better correlation between RAST and bronchial provocation (69,5%) than between skin-prick-test and bronchial provocation (65%). The correlation concerning the skin-brick-test and RAST was 55% with d. farinae and 59% with d. pteronyssinus. There was no correlation between PRIST and RAST, RAST and eosinophiles, therapeutic effects of hyposensitization and positive allergen tests. After one year of therapy, the conditions of 87,5% (only mite sensitization) respectively 92% (mixed sensitization) of patients improved. Another group of sensitized children was only treated by removal of house dust mite allergen and anti-allergic and bronchodilating drugs. 43% (mixed allergy) respectively 54% (only mite sensitization) had less asthma problems. After the hyposensitization the children showed a significant improvement. There was no difference in the therapeutic effect after hyposensitization against d. farinae or d. pteronyssinus.

Adolescent↗
PubMed1984

Liquid chromatographic determination of lipophilicity with application to a homologous series of barbiturates.

A graphical method for determining the lipophilicity of the members of a homologous series of barbituric acids, from a consideration of their reverse-phase HPLC retention data, is described. The HPLC parameter used as the index of lipophilicity, RQ, is shown not only to form excellent correlations with the more commonly employed indices of lipophilicity, Rm and log P, but also to have a predictive capability for those log P values that had not previously been determined experimentally.

Barbiturates↗
PubMed1984

In vitro fertilization in Norfolk, Virginia, 1980-1983.

Three years of progress of the Vital Initiation of Pregnancy (VIP) Program in Norfolk is reported. No conception resulted from 41 oocyte aspirations during spontaneous menstrual cycles in 1980. An average of 3.7 oocytes per cycle, or a 73.5% recovery rate, resulted in 362 human menopausal gonadotropin/human chorionic gonadotropin-induced cycles from January 1981 to March 1983. Forty percent of the oocytes recovered from these cycles were preovulatory, 35% atretic, and 25% immature. Immature oocytes were often matured in vitro, fertilized, and found to produce pregnancies. A total of 62 pregnancies occurred, which represents a 17 or 23% pregnancy rate, based on laparoscopies or embryo transfers, respectively. There were 11 preclinical and 7 clinical miscarriages. Twenty-nine normal babies have been delivered, including a set of twins. The remainder appears to be normally progressing pregnancies. Polyspermia was observed in 8.8% of the fertilizable oocytes.

Adult↗
PubMed1984

Three years of in vitro fertilization at Norfolk.

During the 3 years from 1981 to 1983, 319 consecutive patients in 560 cycles were treated in a program of in vitro fertilization at Norfolk. All patients were stimulated by human menopausal gonadotropin supplemented by human chorionic gonadotropin. There were transfers in 429 cycles, resulting in 105 pregnancies. Over the 3-year span, the pregnancy rate by cycle was 19%; by transfer, 25%; and by patient, 33%.

Adult↗