Cellular uptake of L-lactate in mouse diaphragm

Early uptake curves of L-lactate and of mannitol were measured in quartered, incubated mouse diaphragms. Uptake was determined at 15, 30, and 45 s for various concentrations of lactate in the external solution as well as in the presence and absence of the competitive inhibitor of lactate transport, alpha-cyano-4-hydroxycinnimate. In normal preparations, when the external lactate concentration was 10 mM or less, the ratio of lactate-to mannitol space in the tissue was 1.7. This value was nearly independent of time and of external concentration. In normal preparations, when the external lactate concentration was greater than 10 mM, the ratio of lactate-to-mannitol space rose with time. At a fixed time, however, this ratio fell with increasing lactate concentration. In the inhibited preparations, the ratio of lactate-to-mannitol space rose with time at all concentrations. When lactate concentration was greater than 5 mM, this ratio was independent of the external concentration. The results suggest that there are two modes of lactate entry into these muscle cells. Entry can occur by means of a saturable system. When external lactate concentration is low, entry rates for this process are rapid compared with diffusional rates. This system probably saturates at concentrations near 10 mM and can facilitate transport in either direction. In addition, an appreciable passive leak is present. This leak accounts for about one fourth of the membrane transfer when external lactate is low, but is equal to the carrier transfer when lactate concentration is 30 mM. A model was developed to describe the entry of a permeating solute, such as lactate, into an isolated tissue.

Continuous 20-24 hr Esophageal pH-monitoring in infancy

With the aid of a specially designed combination electrode for infants, 20-24 hr monitoring of esophageal pH was undertaken in 15 infants, aged 5 wk-11 mo. Results demonstrated that the reflux time pH less than or equal to 4 was valid for this age group as for adults, to differentiate between physiologic and pathologic reflux. A new parameter, that of clearance time, defined as normalization time required to return to initial pH, was introduced to improve pH assessment. Both parameters showed a highly significant correlation in relation to each other, and were consistently in accord with the clinical symptoms.

Effect of somatostatin on rat exocrine pancreatic secretory process in normal and diseased state

The effect of somatostatin on the secretory process of the rat exocrine pancreas has been studied using a combined in vivo- in vitro system. Somatostatin in a concentration of 5 x 10(-6) g/kg/h was infused alone or in combination with low (5 x 10(-7) g/kg/h) and high (5 x 10(-6) g/kg/h) doses of synthetic caerulein. All aspects of the secretory process were then studied in vitro using isolated pancreatic lobules. Somatostatin inhibits both basal and stimulated discharge of enzymes and newly synthesized proteins thus leading to increased enzyme content. The stimulatory action of low doses of caerulein is nearly totally blocked, however, the induction of an acute non-hemorrhagic interstitial pancreatitis due to supramaximal doses of caerulein is not prevented, but only reduced in its severity. Furthermore, somatostatin infusion following the induction of pancreatitis has a beneficial effect on recovery, since increase levels of pancreatic enzymes in blood are quickly reduced and cellular infiltration of the diseased pancreas is nearly prevented.

Acute cardiovascular reactions after cigarette smoking

The effect of cigarette smoking on the cardiovascular system was determined in the following way: Two cigarettes of relatively high (1.54 mg) and very low (0.08 mg) nicotine content were smoked and compared to sham smoking. After inhalation under standardized conditions there was a relatively high increase of the plasma nicotine levels and a subsequent exponential decrease. Two hours after smoking the levels were still elevated. After 2 low nicotine cigarettes there was a significant small short-term increase. The changes of the pulse rate were directly related to the nicotine levels and the pulse pressure transit time from the heart to the calf and the digital blood flow was indirectly related to them. The regulation of these parameters is exactly related with the nicotine levels probably through the release of catecholamines. The cardiovascular reactions after smoking may indicate the additional myocardial work load after cigarettes of different nicotine content.

Evaluation of smoking-induced effects on sympathetic, hemodynamic and metabolic variables with respect to plasma nicotine and COHb levels

The effect of smoking cigarettes containing 1.5 mg and 0.08 mg nicotine per cigarette and of sham-smoking was studied in six healthy habitual smokers. Levels of carboxyhemoglobin (COHb) and plasma nicotine were measured simultaneously with hemodynamic variables, such as heart rate and blood pressure, and with the metabolic parameters, plasma DBH, cortisol, blood glucose, lactate and free fatty acids. All variables, with the exception of COHb are dose related to plasma nicotine levels. Blood pressure, heart rate and lactate show simultaneous peaks together with maximal nicotine levels, while DBH and cortisol, blood glucose and free fatty acids show a delayed reaction compared to nicotine concentrations. No effects of COHb, even with levels up to 5.6 +/- 0.5% have been observed on the variables investigated. These results demonstrate, that it is nicotine which induces considerable hemodynamic and metabolic alterations after smoking.

[Pelvic fractures in children: clinic, late results, biomechanic (author's transl)]

From 1917--1976 68 pelvis fractures of children (up to 14 years) were hospitalized at the department of Surgery, University of Göttingen. About 75% were traffic accidents. The lesions prefer the iliosacral joints, symphysis and the biogenic connections. Experimental compressions confirm the clinical fractures. The controls show sufficient subjective results. Because of pelvis dislocation and scoliosis controls are necessary.

[Behaviour therapy of autoagression with the Lesch-Nyhan-syndrome ( author's transl)]

Successful behaviour therapeutic treatment of autoagression in a child with Lesch-Nyhan-Syndrome was combined with the establishment of alternative behaviour at the same time. Treatment applying negative stimuli could be avoided.

[Raynaud's phenomenon in dialysed patients (author's transl)]

In 158 uraemic patients on haemodialysis complaints resembling Raynaud's disease were observed more frequently (85 patients = 54%) than in an equal number of age and sex matched control persons (10 probands = 6%). The complaints were also registered in the arm without the fistula. Triggering causes were exposure to cold or isometric muscular exercise. The complaints were slightly more frequent in women and occurred in 28% prior to dialysis in the terminal stage of renal insufficiency. They were improved only in a minority of those treated with haemodialysis, however they disappeared after successful renal transplantation. Veno-occlusive plethysmographic investigations showed that in asympatomatic patients the resting perfusion at room temperature, the perfusion in reactive hyperaemia, and perfusion at 0 degrees C were not different from control persons. Patients with Raynaud's phenomenon had on average a diminished resting perfusion and a normal perfusion after reactive hyperaemia. The perfusion at 0 degrees C was lower than in asymptomatic patients but still higher than in patients with Raynaud's disease. Increased cooling of the skin and delayed rewarming were objectively measured by using skin temperatures. There was not correlation between the complaints or perfusion values and the vibration threshold.

[Effects of temperature and light variations, and of radiothyroidectomy on body weight regulation in the European hamster (Cricetus cricetus) (author's transl)]

Regain of body weight in European Hamsters after fasting was investigated at various periods of the year and under different ambient conditions (fig. 1) with and without radiothyroidectomy. 1. Weight gain after food deprivation proceeds at rates which vary with the season. It is faster in spring and summer than in winter. 2. Variations in ambient temperature and in light conditions do not influence the daily weight gain and the relative rate of weight increase (fig. 2,3). 3. Radiothroidectomy depresses these two parameters in winter as well as in spring, and lowers the level of the set point of the regulating mechanism (fig. 4,5).

[Urodynamic measurements in enuretics]

Distal urethral stenosis in girls as well as meatal and bulbar narrowed urethral segments in boys are still subjects of discussion about their pathologic value in the literature. The urodynamic findings in enuretic children by urethral pressure profile and cystometry frequently point to a outflow resistance. Calibration with bougies à boule, urethroscopy and permictional cysturethrography disclose such urethral narrowing. The survey of our own 107 enuritic children shows that urethrotomy has given good results relative to urodynamic data. The effect of methantheline medications consists in suppressing the hyperactivity of the detrusor.