Somatic hybridization of amino acid analogue-resistant cell lines of potato (Solanum tuberosum L.) by electrofusion

Intraspecific somatic hybridization between amino acid analogue-resistant cell lines of potato (Solanum tuberosum L.) has been carried out following electrofusion of protoplasts. In initial analytical electrofusion experiments (1 mm electrode separation) optimal fusion conditions were determined by changing the fusion medium (addition of Ca and/or spermine) and the electrical parameters. Subsequently, in large scale experiments, cell suspension protoplasts of aec-1, a variant resistant to AEC, were fused with the same type of protoplasts of 5mt-26 or 5mt-27, both variants resistant to 5MT and cross-resistant to 3 FT. After an extensive selection procedure only somatic hybrid lines of aec-1 + 5mt-26 were obtained. The resistance traits of aec-1 and 5mt-26 were expressed fully, indicating that the variant characters involved are transmitted dominantly. Quantitative examination of the free amino acid content revealed characteristics of both the parental cell lines in most of the somatic hybrids. However, initially selected double resistant colonies from fusions of aec-1 + 5mt-27 lines appeared not to be somatic hybrids.

Estimation of the determinants of transcutaneous oxygen tension using a dynamic computer model

A dynamic model for oxygen transport within the outer layers of the skin and a tcPO2 sensor has been developed. By comparing model simulations with clinical measurements from adults, it is possible to analyze some of the physiologic and physical determinants of the tcPO2 measurement. The results indicate that the permeability of the epidermis is a significant parameter when using a microcathode sensor. Using this model, the values obtained for normalized stratum papillare blood flow and metabolic oxygen consumption of the dermis are higher than those seen for other models.

Halothane hepatitis in a prospective study of postoperative complications

In a prospective study comprising 2609 consecutive surgical patients, of whom 1166 were anesthetized with halothane, four cases of hepatitis were encountered. The incidence of hepatitis among those who received halothane was 1:292 in our material. The high incidence may be explained by the recognition of milder forms of hepatitis and by the selection of the series (over 40 years). Serum alanine aminotransferase should be investigated in all patients with postoperative pyrexia of unknown origin if mild forms of halothane hepatitis are to be discovered. The patient's history should be carefully examined for previous postoperative pyrexia of unknown origin following halothane anesthesia, in which case other anesthetics should be chosen.

Dissociation of renal and respiratory effects of acetazolamide in the critically ill

The effects of acetazolamide on renal and erythrocyte carbonic anhydrase were studied in 12 critically ill patients. In the first part of the investigation (n = 6) we examined the renal effects of increasing doses of acetazolamide. The maximal renal excretion of water and bicarbonate was achieved with acetazolamide 2.5-5 mg kg-1 i.v. In the second part (n = 6), the associated respiratory effects of the effective renal dose of acetazolamide 5 mg kg-1 were evaluated. We found a statistically significant 4% decrease in pulmonary carbon dioxide excretion in the 10-min sampling period immediately following the administration of acetazolamide, but thereafter carbon dioxide elimination proceeded at a normal rate. The observed carbon dioxide retention is clinically unimportant, and we recommend acetazolamide as an effective means of eliminating surplus water and bicarbonate in the critically ill.

The early history of psychotherapeutic drugs

The four most frequently used groups of drugs in psychiatric therapy are: neuroleptics, antidepressants, anxiolytics, and lithium salts. Their introduction came largely during the past 3 decades. This review summarizes the history of the research that led to their discovery and to the present concept of their modes of action.

Age-related changes in sebaceous wax ester secretion rates in men and women

Sustainable rates of sebaceous wax ester secretion were measured on the foreheads of 109 men and 167 women, aged 15-97. Each measurement was made after first depleting the cutaneous sebum reservoir by overnight absorption of lipid into a layer of bentonite clay. Lipid was then absorbed for 3 h into fresh clay in which two 2-cm cloth disks were embedded. The absorbed lipid was extracted from the disks with ether and analyzed for wax esters by thin-layer chromatography. For both men and women there was a wide range of wax ester secretion rates at all ages. Rates were highest in the 15- to 35-year-olds and appeared to decline continuously throughout the adult age range. Values of log(wax esters) were better correlated with age than the untransformed values of wax ester secretion. The equations of best fit of log(wax esters) vs age suggested that sebum secretion declines about 23% per decade in men and 32% per decade in women.

Phenylalanine and tyrosine accumulating cell lines of a dihaploid potato selected by resistance to 5-methyltryptophan

The selection and characterization of 5-methyltryptophan (5-MT) resistant cell lines is described in a dihaploid potato, clone H(2)578(007). The frequency of resistant calli was increased by treatment of a cell suspension with N-ethyl-N-nitroso-urea. Two lines, 5-MT-21 and 5-MT-26, accumulated tyrosine (160 nMol and 1546 nMol/g fresh callus), and the third, 5-MT-27, accumulated both tyrosine (841 nMol/g fresh callus) and phenylalanine (451 nMol/g fresh callus). In the wildtype tyrosine and phenylalanine content was 65 nMol and 42 nMol/g callus, respectively. The tryptophan content of line 5-MT-26 was significantly increased, from 20 nMol/g to 76 nMol/g fresh callus. The total free amino acid content of the three variant cell lines was higher than that of the wildtype. Variant cell lines 5-MT-21, -26 and -27 showed a low degree of resistance to 5-MT, when grown on a selective medium and were cross-resistant to parafluorophenylalanine and 3-fluorotyrosine, analogues of phenylalanine and tyrosine.

Relationship between arterial and heated skin surface carbon dioxide tension in adults

Carbon dioxide tension was measured on heated skin surface (PSCO2) and in arterial blood (PaCO2) in eight adult patients during intermittent positive pressure ventilation. A total of 299 PaCO2-PSCO2 measurements were performed at electrode temperatures of 45 degrees C, 43 degrees C and 38 degrees C. The PSCO2-PaCO2 relation was evaluated using: 1) linear regression, 2) PSCO2/PaCO2 ratio and 3) temperature correction methods. Both linear regression and ratio indicate temperature dependency of the PSCO2-PaCO2 relation. The temperature correction method was done with a blood PCO2 temperature coefficient of 4.6% per degrees C and at two temperatures: electrode temperature (according to Severinghaus) and estimated capillary blood temperature. The results indicate that the relation between PaCO2, PSCO2 and electrode temperature is constant enough to permit estimation of PaCO2 from PSCO2 during stable circulatory conditions.

Oxygen uptake and carbon dioxide elimination after acetazolamide in the critically ill

Acetazolamide, which reversibly inhibits carbonic anhydrase, is a useful diuretic in alkalotic and over-hydrated patients. In two earlier investigations we have consistently found increases in the arterial and venous oxygen saturation and tension when patients were treated with acetazolamide 15 mg . kg-1. A plausible explanation of this phenomenon is that acetazolamide diminishes oxygen consumption. In the present study we measured oxygen uptake in 10 critically ill patients. We found a minor and statistically insignificant decrease in oxygen consumption. Nevertheless SVO2 increased from 0.77 to 0.83 and PVO2 from 5.9 kPa to 6.8 kPa. It is still not possible from this investigation to determine the origin of the improvement in blood oxygenation. The inhibition of carbonic anhydrase caused a CO2 retention of 5.8% of the total CO2 production. An increase in body stores of CO2 of this magnitude is without clinical significance.

Secretion and absorption of nutrients in the alimentary tract of reindeer fed lichens or concentrates during the winter

Water, organic matter (OM), N, Ca, P, K, Na, and Cl exchange was estimated in the alimentary tract of reindeer given concentrate or lichen diets alone or supplemented with minerals. Chromic oxide was used as a nondigestible marker and results are discussed in relation to inaccuracies of this marker technique. The pattern of water, OM, and N exchange was similar to other ruminants; over 61% of OM digestion was due to the rumen–reticulum plus omasum and abomasum (stomachs). For the concentrate diet, 40–60% of N digestion occurred in the stomachs. Apparent absorption of Ca, P, and Mg in the stomachs was linearly related to intake. Ca and Mg supplemented to lichens was excreted because of an inability of the intestines to recover mineral secreted into duodenal contents. In contrast, the jejunum absorbed P added to the diet. Excretion of K in feces at 0.076 mM/g fecal dry matter placed a limit on K absorption; it was negative on the lichen diet. Cl was absorbed in the small and large intestines. Supplemental Na, part of the P, Ca, and K, but none of the supplemental Mg added to the lichen diet was absorbed. Lichens appeared to bind some minerals and could thereby place a limit on their absorption.

Fournier's gangrene: 5 patients treated with hyperbaric oxygen

The classic syndrome of Fournier's gangrene was observed in 5 men with involvement of the external genitals and lower abdominal wall. Mixed flora of anaerobic and aerobic microorganisms were grown, and extensive necrosis of the skin and subcutaneous gas were present in all patients. Soon after hospitalization all 5 patients were treated by excision of all necrotic and undermined tissue, intravenous broad-spectrum antibiotics and hyperbaric oxygen administered at 3 atmospheres of pressure. One patient died of septic shock without any response to the therapy. The infection subsided shortly after the hyperbaric oxygen was instituted in the remaining 4 patients, who were cured. It is proposed that the treatment of Fournier's gangrene should be limited to centers capable of administering hyperbaric oxygen therapy. Our series does not prove that hyperbaric oxygenation is necessary for successful treatment but evidence suggests a beneficial effect of such therapy for nonclostridial gas gangrene.

The effect of mineral supplements on nutrient concentrations and pool sizes in the alimentary tract of reindeer fed lichens or concentrates during the winter

Domestic reindeer (Rangifer tarandus tarandus L.), fed a mixed lichen or concentrate diet with or without a mineral supplement, were killed, and 21 segments of the digestive tract were analyzed for weight of digesta and concentrations of water, organic matter (OM), N, Ca, P, Mg, Na, K, Cl, and S. Trends in alimentary nutrient concentrations were of two patterns: (A) Ca, P, Mg, S, OM, and N increased in concentration per unit wet weight in ruminal to omasal contents and, followed by a decline from abomasal to jejunal contents, there was a steady increase to the rectal contents; (B) water, Na, Cl, and, with some modification, K decreased in concentration from the small intestinal to the rectal contents. The concentrate diet was associated with significantly increased body weight, plasma P levels, and N, P, and Mg levels in most sections of the alimentary tract. Mineral supplementation suppressed concentrations of N in the entire alimentary tract of lichen-fed reindeer but was associated with increased concentrations of P, Ca, and Mg in the entire tract of both the concentrate and lichen diets.

Stroke volume measured by pulsed ultrasound Doppler and M-mode echocardiography

The velocity of the bloodstream in the ascending aorta was measured by pulsed ultrasound Doppler. The diameter of the aorta was measured by M-mode echocardiography. Forty-three measurements were performed in six patients, who all had a Swan-Ganz catheter. The calculated stroke volumes from the Doppler-Echo method were compared with the stroke volumes measured by the thermodilution technique, which was performed simultaneously with the Doppler measurements. The correlation between the measurements was good (r = 0.08). It is concluded that it is possible non-invasively to measure stroke volume (and cardiac output) by means of ultrasound Doppler and an echocardiograph.

Pharmacokinetics of the gamma-aminobutyric acid agonist THIP (Gaboxadol) following intramuscular administration to man, with observations in dog

The pharmacokinetics of the gamma-aminobutyric acid (GABA) agonist, THIP (Gaboxadol) has been studied following intramuscular administration of 10 or 20 mg THIP-monohydrate to six healthy human volunteers. Additional experiments with special reference to the possible occurrence of non-linear kinetics and to estimation of the efficiency of absorption were carried out in three beagle dogs. As estimated from the dogs, absorption of THIP from the site of injection was efficient (F = 0.94 +/- 0.16, mean +/- S.D., in 8 experiments). The time course of the THIP serum concentration was in all experiments adequately described by an open 1-compartment linear model. In most individual experiments a near maximum concentration was present at 15 or 10 min. after the administration to man and dog, respectively. In some subjects and dogs an uncertain relation was found between dose and the time integral of the THIP serum concentration, but the mode of variation did not suggest deviations from first-order kinetics at high doses or concentrations. The rate constant of elimination was estimated to 0.50 +/- 0.13 hr-1 and 0.52 +/- 0.13 hr-1 following injection of a 10 or 20 mg dose, respectively, to man (mean +/- S.D., n = 6), and similar values were obtained from the dogs.

Ploidy levels in leaf callus and regenerated plants of Solanum tuberosum determined by cytophotometric measurements of protoplasts

In potato (Solanum tuberosum) instabilities in nuclear DNA content in callus cells of a monohaploid and a dihaploid and in tuberprogenies of a regenerated, doubled dihaploid plant were assessed by cytophotometry in isolated, purified protoplasts. Leaf protoplasts of a tetraploid variety have nuclei with 3.6±0.08 pg of DNA. In callus protoplasts a dihaploid showed 3 and a monohaploid 6 ploidy levels. Progeny of a plant, doubled and regenerated from dihaploid callus, showed mixo-euploidy, indicating an instability similar to the dihaploid callus; in addition, there are mixo-aneuploid cells.These findings confirm and extend earlier observations based on chromosome counts in other genotypes of potato. The experimental approach can be applied to a variety of other purposes.

Analgesic, respiratory and endocrine responses in normal man to THIP, a GABA-agonist

In a controlled study, the effects of THIP (a synthetic gamma-aminobutyric-acid-agonist) on respiratory function (ventilatory response to CO2), first detection of stimulation (electrical stimulation of a tooth), pain threshold, magnitude of maximal tolerated pain stimulation, and plasma cortisol, prolactin and glucose were investigated in six normal men. Intramuscular injection of THIP in dosages of both 10 mg and 20 mg increased the magnitude of stimulus before first detection, and the pain threshold as well as the maximal tolerance of pain stimulation. THIP did not lead to changes in respiratory function, or in plasma cortisol, prolactin or glucose, suggesting an analgesic action independent of opiate receptors.

Plasma levels of progesterone and oestradiol-17 beta in reindeer (Rangifer tarandus tarandus) during pregnancy

The plasma concentrations of progesterone and oestradiol-17p during pregnancy and the first 20 days after parturition were estimated in reindeer. The concentration of progesterone in the period 75–25 days prior to parturition was significantly higher than in the period 200– 75 days prior to parturition (P < 0.001). During the last 25 days before parturition the concentration decreased significantly. The concentration of oestradiol-17β was in most cases below 70 pg/ml until 50 days prior to parturition. During the last 25 days of pregnancy there was a significant increase in oestradiol-17β and the ratio progesterone/ oestradiol-17β was markedly lower than in the period 75–25 days before calving.

Nitroglycerin for ergotism. Experimental studies in vitro and in migraine patients and treatment of an overt case

Ergotamine was used to induce arterial contraction in vitro (measurement of isometric tension in segments from 3 human temporal arteries) and in vivo (peripheral systolic blood pressure measured by strain gauge plethysmography in 5 migrainous patients). In both these models of ergotism, the directly acting vasodilator nitroglycerine (NTG) effectively relieved the ergotamine-induced arterial contractions. A case of ergotism treated successfully with NTG infusion is reported. The diagnosis was based on history and measurement of peripheral systolic blood pressure by strain gauge plethysmography. The latter technique was also used to monitor the response to treatment for 20 h. Blood levels of ergotamine during ergotism were in the therapeutic range. Possible explanations for this finding are discussed.

Aberrant left pulmonary artery. Review of surgical results and report of a successfully treated case

Aberrant left pulmonary artery is a rare anomaly which can cause severe respiratory distress by compressing the distal trachea. The most reliable diagnostic measures are barium swallow, which in most cases shows an anterior indentation of the oesophagus, and a pulmonary arteriogram to provide a conclusive diagnosis. Tomography of the trachea and the main bronchi should be performed, in order to detect possible additional malformations in the airways. In severely symptomatic cases, surgical correction should be done before a life-threatening situation has developed. The correction is best performed through a left thoracotomy, with transposition of the left pulmonary artery and end-to-side anastomosis to the main pulmonary artery. The postoperative course may be difficult, and the patient may require respirator support for two to three weeks. Early surgical revision must be considered if symptoms persist, if additional stenosis is demonstrated, or if malformations such as complete tracheal rings are observed in the area of compression at the time of the vascular correction.

Respiratory, analgesic and endocrine responses to an enkephalin analogue in normal man

In a controlled study, the effect of a new enkephalin analogue (FW 34-569, Sandoz) on respiratory function (ventilatory response to CO2), pain threshold (hot plate technique), and plasma cortisol, prolactin, growth hormone, luteinizing hormone (LH) and follicle-stimulating hormone (FSH) was investigated in six normal subjects. One milligram of enkephalin, but not 0.5 mg, resulted in a significantly decreased ventilatory response to CO2, although mean values were not significantly different from saline control values (0.05 less than P less than 0.1). Neither 0.5 mg nor 1.0 mg enkephalin influenced pain threshold, but doses stimulated growth hormones and prolactin release and inhibited the release of cortisol and LH, while FSH remained unchanged.

Pulmonary hemodynamics during direct diagnostic laryngoscopy

Acute changes in systemic and pulmonary hemodynamics, together with blood gas changes, were recorded during diagnostic laryngoscopy for biopsy. Laryngoscopy was performed under general anesthesia, and two groups of patients were studied, one was ventilated intermittently, the other had controlled ventilation through an endotracheal tube. PaCO2 rose in both groups, but only in the intermittently ventilated patients did the PaCO2 values increase above normal levels. No significant difference in cardiovascular response was found between the two groups. Significant changes were: increases in mean arterial pressure, pulmonary arterial mean pressure, pulmonary capillary wedge pressure and central venous pressure. The increases reached a maximum during the laryngoscopic procedure and returned towards control values when the laryngoscope was removed. Systemic and pulmonary vascular resistance remained unchanged. The rises in PaCO2 and sympathetic stimulation are believed to the the man causes for the observed hemodynamic changes.

Esophageal peristalsis before, during, and after food intake in healthy people

Esophageal peristalsis in the middle and distal esophagus was analyzed in nine healthy people before, during, and after food intake. A significant increase in amplitude of contractions occurred during and after eating. Furthermore, a significant increase in duration and propagation time of contractions occurred in the distal part of the esophagus during food intake.

Transcutaneous oxygen measurement during thoracic anaesthesia

The value of transcutaneous oxygen tension (tcPO2) as an oxygen parameter during uncomplicated thoracic anaesthesia was examined in ten patients anaesthetized with oxygen-nitrous oxide and enflurane or flunitrazepam/fentanyl. tcPO2 was measured with the Radiometer TCM-I monitor at 45 degrees C. Measuring interference due to the anaesthetic agents was not observed. tcPO2 was found to be lower than the arterial tension (PaO2) at any inspiratory oxygen fraction (FIO2). When the peroperative readings were related to the preoperative values, no statistically significant difference was found between PaO2 and tcPO2 at FIO2 - 0.5, 0.4 and 0.3 (P greater than 0.3). Linear regression between PaO2 and tcPO2 shows disparity in pre- and peroperative regression. tcPO2 (preoperative) = -2.2 + 1.03 X PaO2 (4 = 0.89) tcPO2 (preoperative) = +3.1 + 0.56 X PaO2 (r = 0.87). This disparity indicates a decrease in the tcPO2/PaO2 ratio with increasing PaO2. It is concluded that tcPO2 cannot substitute for PaO2, but tcPO2 and PaO2 proved to be equally useful as oxygen parameters in the examined patients. Interpretation of tcPO2 during anaesthesia, however, necessitates a preoperative measurement as reference.

Primary and secondary displacement of central venous catheters

The purpose of this study was to investigate the frequency of primary and secondary displacement of central venous catheters. One hundred and two central venous catheters, inserted through a peripheral or a central vein before surgery or in the intensive care unit, were controlled by chest X-ray 5-720 min after insertion. The number of primarily displaced catheters was 27. Of these, the position was corrected in 8. Thereafter, the 83 correctly placed catheters were observed for 4-560 h. The number of X-ray controls was 2-24. The number of secondary displacement was 2, whereas 12 catheters showed minimal secondary displacement. The rate of complication was very low. We conclude that chest X-ray immediately after insertion of central venous catheters is absolutely necessary, but since the number of secondary displacements is very low, daily chest X-ray control is not necessary. We also conclude that the internal jugular vein is the best route for introducing a central venous catheter, since complications are very few and the number of displacements is very low.

Correlation of transcutaneous oxygen tension to blood flow in heated skin

Blood flow regulation in the foot under a heated (43 degrees C) transcutaneous oxygen tension (tcPo2) electrode was studied in six young subjects. Blood flow under the electrode was estimated from the electrical power consumption of the thermostatistically-controlled heating element in the electrode. Changes in arterial and venous pressures, and thereby in perfusion and transmural pressure and blood flow were induced by elevation and lowering of the foot and by venous stasis. tcPo2 was significantly and positively correlated to the blood flow under the electrode, and blood flow neither showed autoregulation nor vasoconstrictor response as judged from the power consumption. In contrast the blood flow in normal unheated skin measured simultaneously by the 133-Xenon technique showed autoregulation as well as vasoconstrictor response. It is concluded that tcPo2 is a parameter determined by many variables, of which the arterial blood pressure is of particular clinical importance.

Isolation of a nitrate reductase deficient mutant of Pisum sativum by means of selection for chlorate resistance

After EMS treatment of seeds of the Pisum variety 'Rondo' a chlorate resistant mutant was isolated which showed a decrease in the in vitro activity of the enzyme nitrate reductase of roughly 95%. The mutation is monogenic and recessive. The mutant shows a decrease in protein content, and an increase in the amount of nitrate accumulated and in the activity of the enzyme nitrite reductase. On a liquid nutrient medium containing nitrate as the sole nitrogen source and in soil, the mutant grows very poorly due to necrosis of the leaves. On liquid medium containing ammonium, either with or without nitrate, growth is as good as that of the parent variety.

Effect of arterial and venous pressures on transcutaneous oxygen tension

The effect of changes in arterial and venous pressures on transcutaneous oxygen tension (tcPO2) were studied in ten young subjects. The tcPo2 electrode was mounted on the foot, and changes in blood pressures were induced by elevating and lowering the foot and by inflating a cuff around the thigh. tcPo2 decreased gradually during elevation at a rate of 1% per mmHg reduction in arterial pressure. tcPo2 increased during dependency and venous stasis, at a rate of 0.5% per mmHg increase in venous pressure. We propose that tcPo2 is a function of the blood flow under the electrode, and that normal blood flow regulation is abolished in the heated tissue under the electrode.

The minor alcoholics and their treatment

The codiscoverer of disulfiram's usefulness for alcoholics reports on the development of Denmark's present system of alcoholism treatment and the treatment facilities.

The influence and possible recombination of genotypes on the production of microspore embryoids in anther cultures of Solanum tuberosum and dihaploid hybrids

In addition to physical and chemical factors, genotype appears to be a very important factor influencing success in anther culture. Recombination by making crosses with selected responding clones has been introduced as a possible helpful method to positively influence the success and response type via the factor genotype. From the progeny of such a cross, one genotype could be selected, producing in 30 to 40 percent of the cultured anthers, fully developed embryoids and plantlets, which are a mixture of polyploids, dihaploids and monohaploids.Further, a pleiotropic marker 'embryo spot' visible as a 'nodal band' in the plant stage, has been used to confirm the microsporic origin of dihaploids and polyploids and to prove their homozygous nature. This marker also shows potential use in confirming the origin of calli from individual microspores.