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Biomedical subjects

R Keller

Publications and source records attributed to R Keller.

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

Relations between clinical signs and lung function in bronchial asthma: how is acute bronchial obstruction reflected in dyspnoea and wheezing?

To compare the degree of clinical manifestations and bronchial obstruction in acute asthma, we correlated lung function tests with the clinical symptoms in 33 patients during acute attacks of bronchospasm induced by specific and non-specific inhalation challenge tests and compared the results with similar challenge tests in 12 healthy subjects. It could be shown that about 60% of the patients did not reveal wheezing or dyspnoea despite marked bronchial obstruction, thus indicating a poor sensitivity of clinical symptoms in relation to the objective alterations in the lung function tests. We therefore conclude that the degree of bronchospasm may be seriously underestimated if it is related only to the subjective complaints and the physical sign of expiratory wheezing. In particular, during inhalative bronchial challenge tests the asthmatic airway reaction should be carefully monitored by serial or continuous lung function tests in order to avoid major complications.

Adult↗
PubMed1985

[Oxygen home therapy in chronic respiratory insufficiency. Report of experience with 70 patients].

The effect of home long-term oxygen therapy has been evaluated in 70 patients (52 men and 18 women) with chronic respiratory insufficiency due to chronic obstructive pulmonary disease. The mean duration of the observation period was 17.5 months, lasting at least 6 months and in a few cases over 40 months. The cumulative death rate was 22.6% in the first 12 months, 36.5% after two years and 40.7% in the third year. Compared to a previous period of 19.5 months there was an obvious reversal in hypoxemia, an increase in physical capacity and a reduction in the hospitalization rate. Patients with marked respiratory failure and with the clinical features of the "blue bloater" type of chronic bronchitis responded better to the home oxygen therapy than a group of "advanced pink puffers" with hypercapnia and high pulmonary arterial pressure. The present results do however confirm the beneficial effects of long-term domiciliary oxygen administration, and should encourage critical use of this new therapeutic regimen according to the indications so far recommended.

Aged↗
PubMed1985

[Current problems in weaning from the respirator].

Weaning from the respirator is obviously the most time-consuming phase in mechanically ventilated patients. Major problems still arise in the early detection and elimination of risk factors which may impair adequate spontaneous breathing. Detailed physiological consideration of the respiratory disability should distinguish between defects in lung mechanics and inspiratory muscle failure. Thus, proper mechanical ventilation can be established in order to restore or to train the respiratory muscles (IPPB versus IMV/CPAP principle) during the weaning period. Prior to any extubation, the data on clinical state, results of blood gas analysis and pulmonary mechanics, as well as special tests for estimation of inspiratory muscle strength, are of definite value.

Airway Obstruction↗
PubMed1985

Normal human blood density gradient lymphocyte subset analysis: I. An interlaboratory flow cytometric comparison of 85 normal adults.

An interlaboratory flow cytometric comparison of several commercially available human lymphocyte subset reagents was undertaken in three different laboratories. Fresh Hypaque-Ficoll purified blood mononuclear cells were stained at 4 degrees C or 22 degrees C. Direct or indirect surface immunofluorescence was carried out at all sites using an EPICS V flow cytometer. Fullbright, 10-micron fluorescent polystyrene microspheres were used for optical alignment and standardization. A log integral fluorescent histogram gated on forward and right angle scatter was collected on 1-2 X 10(4) cells for each reagent and the proportion, of positive cell determined for each reagent. With the exception of one reagent, anti-B1, which showed an approximately twofold variation, all three laboratories showed remarkable agreement. Thus there was no significant difference noted for the following reagents: OKT4, CCT4, Leu 3a, Leu 2a, OKT8, or CCT8. We attribute these findings to the availability of quality reagents, precision instrumentation, and a standard lymphocyte preparation.

Adult↗
PubMed1985

Surgical intervention and metastasis.

Recent findings, briefly summarized here, show that the dissemination of neoplastic cells is an early and continuing process; that individual tumor cells in a malignant tumor possess differing metastatic capacities; and that metastases can arise from specific subpopulations of tumor cells. These findings have considerable implications for the understanding and treatment of systemic malignancies. The underlying cause for the finding that surgical removal of the primary local tumor is often followed by considerably enhanced outgrowth of established micrometastases is not yet understood. The trauma and stress associated with surgical intervention does not of itself seem to constitute a major tumor-promoting component. More likely candidates responsible for enhanced outgrowth of metastases after surgery are the removal of the growth-inhibitory restraint that the primary tumor exerts on disseminated neoplastic cells.

Animals↗
PubMed1985

Gastrointestinal transit times of cathartics combined with charcoal.

Oral activated charcoal usually is administered in toxic ingestions along with a cathartic. A study was done in volunteers to determine the rapidity of gastrointestinal transit when activated charcoal was administered with various cathartics. A control of activated charcoal was compared to the gastrointestinal transit times of activated charcoal plus the cathartics magnesium citrate, magnesium sulfate, or sorbitol. Activated charcoal alone produced a mean transit time of 23.5 hours; magnesium citrate catharsis occurred in 4.2 hours, magnesium sulfate catharsis occurred in 9.3 hours, and sorbitol catharsis occurred in 0.9 hours. Sorbitol clearly was the most rapidly acting cathartic.

Administration, Oral↗
PubMed1985

Predictors for early mortality in patients with long-term oxygen home therapy.

The follow-up of 87 patients with long-term oxygen therapy over a 3-year period revealed a mortality of 23.7% during the first year, of 37.4% after 2 years and of 45% after 3 years, respectively. The retrospective analysis of baseline characteristics in order to evaluate the causes for early deaths showed no difference in age, lung function tests nor the degree of respiratory insufficiency documented by serial blood gas analysis between the survivors (n = 61) and the dead (n = 26). However, in the group of early deaths there was a significant increase in pulmonary hypertension (mean pulmonary arterial pressure 40.1 +/- 12.0 mm Hg) compared with the survivors, who had only mild hypertension (mean pulmonary arterial pressure 29.4 +/- 8.9 mm Hg). In addition there was also a lesser response in pulmonary vasodilation during oxygen breathing in the patients who died within the first 2-year period. We conclude that marked pulmonary hypertension with poor response to oxygen breathing is a major limiting factor in the prognosis of patients with long-term oxygen therapy. In contrast neither severe airway obstruction nor pronounced hypoxemia are related to early mortality and should therefore not be considered as a criterion for rapid deterioration and fatal outcome despite oxygen therapy.

Aged↗
PubMed1985

Macrophages in primary and secondary tumor growth: some implications for cancer therapy.

Although it has been convincingly demonstrated that, under in vitro conditions, macrophages manifest an impressive cytolytic potential against a wide array of tumor cells, their role in the control of primary and secondary tumor growth in vivo has proved much more difficult to assess. In the present work, the evidence for the presence, efficient operation and modulation of host antitumor resistance and for a role for mononuclear phagocytes is briefly discussed and exemplified utilizing data derived from an experimental tumor model, the D-12 rat fibrosarcoma, in which macrophages appear to constitute a critical factor.

Animals↗
PubMed1985

Repression of lymphatic metastasis by a second implant of the same tumor.

Previous work in the rat D-12 fibrosarcoma model has shown that the incidence of macroscopic metastasis, located primarily in regional lymph nodes, is markedly increased after surgical removal of a primary subcutaneous tumor implant, in all probability by facilitating the outgrowth of already established micrometastases. The present work shows that a second implant of live D-12 tumor cells into a remote site effectively represses the outgrowth of macroscopic metastases. For the manifestation of the repressive effect, both the time interval elapsing between surgery and reimplantation of tumor cells and the size of the inoculum appear critical. Implantation of heavily irradiated D-12 cells or the prolonged delivery of ascites fluid by osmotic mini-pumps had no such repressive effect on metastatic tumor growth. Corynebacterium parvum administered into the tumor-bearing limb a few days before its amputation, but not into a remote subcutaneous site, suppressed the outgrowth of macroscopic metastases. The occurrence and efficient operation of concomitant tumor resistance in the D-12 tumor model, in which metastasis is primarily via lymphatics and resistance appears to involve a substantial portion nonspecific reactivity, is further evidence for a basic role of tumor/tumor interrelations in determining the final outcome of the host/tumor interaction.

Animals↗
PubMed1984

[Multicenter double-blind study of the action of Broncho-Vaxom in chronic bronchitis].

The efficacy of Broncho-Vaxom has been evaluated by a multicentric working group of physicians in 75 patients with chronic bronchitis using a randomized double-blind trial. Initial data of the selected patients showed no significant differences in history, previous medication, individual state and spirometric lung function values between the control group (n = 39) and the cases treated with the test medication (n = 36). After 30-day initial treatment both physician and patient favoured the active substance (p less than 0.01) although there was statistically no evidence of a curative effect measured by objective criteria. Longterm follow-up over a period of six months again revealed a more effective course in the Broncho-Vaxom group according to individual observations (p less than 0.05). In fact there was an impressive trend towards reduction of clinical symptoms with Broncho-Vaxom medication. However, statistical analysis of individual symptoms' scores and lung function tests did not show significant alterations within the two groups. Taking in account the complexity of bronchitic disease, statistical demonstration of a beneficial effect of Broncho-Vaxom with respect to clinical symptoms and lung function tests probably needs a longer observation period, a larger population and a choice of more sensitive methods.

Adjuvants, Immunologic↗
PubMed1984

[Problems of bacteriological diagnosis of lower respiratory infections using fiberbronchoscopic aspiration of secretions].

Different results have been observed in systematically analysing bacteriological cultures of (a) bronchial secretions aspirated during fiberoptic bronchoscopy and (b) of sputum. In a prospective study of 23 patients with chronic infections of the lower respiratory tract, bacteriological cultures of the sputum showed more bronchopathogenic strains than those of subsequently removed bronchial secretions. These different findings may be attributed to a bactericidal effect of topical anesthetics used during bronchoscopy. To evaluate the influence of anesthetics on the growth of microorganisms, several strains cultured from sputum specimens were exposed to various solutions of the most commonly used anesthetics. The growth of Haemophilus influenzae and Diplococcus pneumoniae was completely depressed by all the tested solutions and dilutions. Only Staphylococcus aureus and several strains of Enterobacteriaceae were resistant even to high concentrations of anesthetic solutions. The results suggest that specimens of bronchial secretions taken by routine fiberoptic techniques cannot be used for reliable bacteriological diagnosis of lower respiratory tract infections.

Anesthetics, Local↗