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Biomedical subjects

P Falk

Publications and source records attributed to P Falk.

At least 73 records · Page 4Linked to original sources
PubMed1986

An antigen present in rat adenocarcinoma and normal colon non-epithelial stroma is a novel Forssman-like glycolipid based on isoglobotetraosylceramide.

A glycolipid with blood group A activity detected in the non-epithelial stroma of normal rat colon but not in epithelial cells (Hansson, G.C., Karlsson, K.-A., and Thurin, J. (1984) Biochim. Biophys. Acta 792, 281-292), was purified to homogeneity from normal rat colon and rat colon adenocarcinoma. Mass spectrometry and 1H-NMR spectroscopy of the intact permethylated derivative and gas chromatography after degradation revealed the structure GalNAc alpha 1----3GAINAc beta 1----3Gal alpha 1----3Gal beta 1----4Glc beta 1----1Cer, with the predominant ceramide containing sphingosine and non-hydroxylated 24:0 fatty acid. This identifies this glycolipid as a novel Forssman-like glycolipid, which is a tumor-associated antigen by definition, since it is not present in the normal rat large intestinal epithelium cells but in rat adenocarcinoma derived from these cells.

Acetaminophen↗
PubMed1985

Relieving dyspnea with an inexpensive and simple method in patients with severe chronic airflow limitation.

The effect of inspiratory resistive breathing training using a simple apparatus was tested in 27 optimally medicated consecutive outpatients with severe chronic airflow limitation, randomly assigned to a test and a control group. Patients trained in their homes for up to 10 min thrice daily and increments in resistance were made, if possible, every fortnight. The control group used the same apparatus, but without inspiratory resistance. Three months from the start of training, the following statistically significant differences between the 2 groups were observed: a marked decrease in dyspnea in the trained group, a 60% versus 22% rise in endurance time on a cycle ergometer at 2/3 of maximal work load, a fall in functional residual capacity, and a fall in respiratory frequency both at rest and during exercise.

Airway Resistance↗
PubMed1984

The effect of radiation alone and of radiation followed by hyperthermia on the vasculature of mouse intestine.

The effect on the vasculature of mouse intestine was observed following: (a) irradiation alone; and (b) irradiation followed at intervals of 0-60 days by hyperthermia. Specimens of intestine were removed after sacrifice and the vasculature revealed by benzidine staining before clearing in resin. The mean visible venous tree (VVT) was used as a parameter for assessing damage. The same hyperthermal treatment was used throughout: 1 h at 41.0 degrees C with the gut externalised. Following irradiation by 9 Gy, the VVT was not significantly reduced in the first 15 days, but decreased steadily by 34% in the next 45 days. In addition two transient reversible reductions occurred: the first immediately following irradiation, not counteracted by hyperthermia and thought to result from spasm; the second after about 40 days, counteracted by heating and thought to be caused by partial occlusion of the arterioles, resulting from irradiation. Reduction in VVT 26 days after irradiation appeared to be independent of dose from 6 to 10 Gy. Sensitivity to hyperthermia was maximal 15 days after irradiation.

Animals↗
PubMed1984

Clinical experience with inspiratory resistive breathing training.

Seventy-seven outpatients with disabling chronic obstructive pulmonary disease have been subjected to a 3-month regimen of inspiratory resistive breathing training using the PEP/RMT set (Astra Meditec). Pulmonary function and exercise tolerance on a cycle ergometer or the 12 min. walking distance were obtained pre- and post-training. A special dyspnoea scoring system was also applied. Sixty-three patients experienced significant benefit from training. Pulmonary function did not change, but a substantial increase in exercise tolerance and a decrease of dyspnoea were apparent, where training was successful.

Breathing Exercises↗
PubMed1984

Improving the ketchup bottle method with positive expiratory pressure, PEP, in cystic fibrosis.

We studied the acute effects of 4 different chest physical therapy regimens using a randomised cross-over design in 14 patients with cystic fibrosis. Treatment A consisted of postural drainage, percussion and vibration; treatment B of postural drainage and periodic application of a face mask with positive expiratory pressure (PEP); treatment C of PEP in the sitting position; treatment D of the forced expiration technique in the sitting position. In terms of sputum expectorated, treatments B and C were superior to treatment D and especially to treatment A (p less than 0.05). Skin oxygen tension, PSO2 was monitored continuously during and for 35 min after treatment. A substantial and prolonged decay in PSO2 was observed during treatment A, quite different from other patterns seen. During and even following treatment C, an increase in PSO2 was noted. PEP was well accepted by the patients, who preferred treatment C, and we suggest it is incorporated in chest physical therapy regimens if the therapeutic objective is to increase expectoration.

Adolescent↗
PubMed1983

The effect of elevated temperature on the vasculature of mouse jejunum.

The effect of elevated temperature on mouse jejunal vasculature was investigated. Both local and lower-body heating were employed, using a hot water bath; heating time was kept constant at 1 hour, bath temperatures ranging from 40.0 degrees C to 43.0 degrees C. Animals were sacrificed after heating, the erythrocytes were stained with benzidine and H2O2 and the blood vessels revealed by mounting in a clearing resin. The earliest damage seen was the disappearance of capillaries, followed by loss of progressively larger vessels. Loss is interpreted as destruction, not merely as interruption of blood flow. A gradient of sensitivity occurs from the inner layer of the jejunum to the outer, the threshold heating temperature required to produce vascular damage being lowest at the inside. Neither temperature gradient, nor early release of gastric juice from the stomach, appears responsible for this differential response. The mean length of intact venous tree was employed as a parameter for assessing the damage.

Animals↗
PubMed1982

Differences in vascular pattern between the spontaneous and the transplanted C3H mouse mammary carcinoma.

The transplanted C3H tumor differs from the spontaneous in its multi-focal origin and in its increasing loss of differentiation. Loss of differentiation is principally important in that even the partial branching into lobes, which occurs in the spontaneous tumour, is lost and that the parenchyma no longer consists of single-layered and multi-layered tubules, as in the spontaneous tumour, but of multi-layered only. Absence of branching removes the interlobular pressures, which in spontaneous tumours lead to infarction of the efferent vessels and sinus formation. Consequently; sinuses are absent from the transplanted tumour and the circulation is thereby improved. In contrast, since the vascular pattern of the spontaneous tumour is preserved and capillaries do not penetrate into the multi-layered tubules, although these have developed into solid cylinders, the diffusion pathway of oxygen is extended, resulting in necrosis at their cores. Accumulating necrotic fluid is at first removed by lymphatics, but subsequently invades the efferent vascular system. These changes are reflected in the pattern of tumour growth and in the radiation responses.

Adenocarcinoma↗
PubMed1982

Noninvasive detection of sublobar bronchial obstructions. An experimental study.

The objective of this study was to develop a noninvasive radiographic method for detection of sublobar bronchial obstructions. The study was primarily done in dogs, where the obstruction was made experimentally. Inspiratory and expiratory films did not show any obvious density difference between lung parenchyma distal to the obstruction and the surrounding lung. A short application of positive end-expiratory pressure immediately followed by a forced expiration, created localized air trapping with relative radiolucency of the lung tissue distal to the obstruction. This method, easily applicable to human studies, may prove useful in early diagnosis of lung cancer with intraluminal obstruction and in detecting non-radiopaque airway foreign bodies. As an example of human application a case of lung cancer in a 57-year-old man is presented.

Animals↗
PubMed1979

Interlaminar connections of tree shrew visual cortex.

The intracortical projections of neurons in layers II and upper III of tree shrew visual cortex were studied after terminal lesions in the supragranular layers of area 17. Examination for terminal degeneration was made using ultrastructural techniques. The majority of degenerating terminals were found in layers V and, to a lesser extent, VI, and were presynaptic to neural profiles in the following distribution: 80.5% on spines of small to medium size dendrites, 19% on dendrite shafts, and less than 1% on neuronal perikarya. Degenerating axons coursed in vertical bundles through layers III, IV, V and VI. These findings are similar to those previously described in rat visual cortex.

Animals↗
PubMed1977

Bone-marrow transplantation in acute leukaemia.

Survival in 33 patients with resistant leukaemia treated by marrow transplantation was compared with that of 37 matched patients treated by conventional and experimental chemotherapy. All patients in the transplant group were rendered free of detectable leukaemia for periods of from 36 days to more than 2 1/2 years, while only 6 patients in the chemotherapy group achieved a haematological remission. Overall survival in both groups was poor; however, 5 patients (15%) in the transplant group remain alive and in haematological remission 1--2 1/2 years after transplantation, while no patient in the chemotherapy group survived longer than 13 months. Bone-marrow transplantation appears to offer a small but distinct possibility of long-term survival in patients with acute leukaemia resistant to conventional therapy.

Adolescent↗
PubMed1977

ABO blood group system and bone marrow transplantation.

The role of the ABO blood group system in determining the outcome of bone marrow transplantation was investigated in 53 patients with aplastic anemia and acute leukemia grafted from HLA-identical siblings. There was no correlation between ABO compatibility and marrow engraftment, graft rejection, or graft-versus-host disease. In 5 recipients with antibodies prior to transplantation to antigens of the ABH system present on the cells of their donors, plasma exchange and antibody absorption in vivo were effective in permitting engraftment of ABO-incompatible bone marrow. These findings indicate that the ABO system is not a clinically significant barrier to successful bone marrow transplantation in otherwise histocompatible individuals.

ABO Blood-Group System↗