A patient with 44 chromosomes.
A patient with Turner syndrome and a 13q14q translocation is described. Not a single such case had been reported. The principal findings in connection with double aneuploidy in humans are discussed.
Child↗
Biomedical subjects
J Sanchez
Publications and source records attributed to J Sanchez.
Management of a harem breeding colony of rhesus monkeys to reduce trauma-related morbidity and mortality.
A management procedure was developed for a harem breeding colony of rhesus monkeys to reduce trauma-related injuries and deaths resulting from the periodic removal of pregnant monkeys for research and their subsequent return to the population. Lower morbidity and mortality rates, a reduced mean conception interval, and a higher mean conception rate occurred when monkeys were maintained in permanent harems to which returning females were reintroduced compared to new social groups formed from aggregates of unfamiliar animals.
Aggression↗
Mechanism of toxin secretion by Vibrio cholerae investigated in strains harboring plasmids that encode heat-labile enterotoxins of Escherichia coli.
A genetically engineered Vibrio cholerae strain from which the cholera toxin genes had previously been deleted was used as a host in which to study the expression and secretion of related toxins and their subunits. Recombinant plasmids encoding heat-labile enterotoxins (LTs) from Escherichia coli of human and porcine origin were expressed in the V. cholerae host, and this resulted in the secretion of the LTs into the extracellular milieu. The secreted LTs were isolated and it was found that the A subunits of human and porcine LT were "unnicked" polypeptides, which indicates that nicking is not obligatory for toxin secretion. V. cholerae strains were also constructed that harbored plasmids encoding either the A or the B subunits of human LT (A+B-, or A-B+). Approximately 90% of the B subunits were secreted from the A-B+ strain, while all of the A subunits expressed by the A+B- strain remained cell associated. This implies that strains synthesizing both subunits assemble the A and B subunits prior to their secretion. We propose that the entry of the toxin into the secretory step of the export pathway is mediated by a secretory apparatus that recognizes structural domains within the B subunit of LT.
Animals↗
Static contraction of the quadriceps muscle in man: cardiovascular control and responses to one-legged strength training.
Knee extension strength training of one leg (ST) (120 maximal contractions per day, 5 days per week for 9 weeks) was performed by 9 healthy young men. Before and after ST, biopsies were obtained from the vastus lateralis muscle of each leg and static quadriceps contractions (SQC) lasting 2 min were performed with each leg under control conditions and after combined vagal and beta-adrenergic blockade with atropine and metoprolol. Maximal voluntary contraction strength (MVC) increased more for the trained leg (TL) than for the untrained leg (UTL) but thigh circumferences and muscle fibre diameters gave little evidence for muscle hypertrophy. In pre- vs. post-training comparisons during SQC at the same relative force (40% of MVC) mean blood pressure (MBP), heart rate (HR) and smoothed rectified electromyographic activity were similar for TL and UTL. Similar findings were obtained for MBP after attenuation of the HR response by autonomic blockade, indicating that MBP, per se, was closely linked to the relative force of SQC. Pre- to post-training reductions in MBP and HR during SQC with each leg at an absolute force of 40% of pre-training MVC were likely due to changes in the pattern of motor unit activation. A lower MBP response to SQC and TL than of UTL after training correlated with a greater capillary density and a lower muscle lactate level for TL.
Adaptation, Physiological↗
Enzymatic adaptations to treadmill training in skeletal muscle of young and old rats.
The activities of lactic dehydrogenase (LDH), hexokinase (HK), citrate synthetase (CS), and 3-hydroacyl CoA dehydrogenase (HAD), were measured in Soleus and extensor digitorum longus (EDL) muscles of four different age groups of male Wistar rats. Young rats (3 months) and old rats (24 months) were trained during 12 weeks by a 3 days a week running exercises session. Each training session was of 2 h. All the enzymatic activities increased between 3 and 6 months in both Soleus and EDL muscles. During aging (6-27 months) Soleus showed about the same percent decrease in enzymatic activities (30%) for the four enzymes studied. In contrast with Soleus, CS activity of EDL increased with age but HK, LDH, and HAD decreased. The training induced an improvement of all enzymatic activities, except for LDH, which decreased with training in same cases. In the old group the training effect was more important than in the young group. When the relative enzymatic activities were compared it was found that Soleus muscle keeps its energy supply enzyme pattern during aging, whereas EDL evolutes to a more oxidative metabolism. Moreover old skeletal muscle remains trainable and training induces an enzymatic adaptation which follows the same pattern in both muscles: an increase of HK, CS, and HAD activities and a decrease of LDH.
Aging↗
Cytologic detection of endometrial carcinoma by the endocyte technique.
Ninety-seven patients admitted for diagnostic curettage of peri- and postmenopausal bleeding underwent cytologic evaluation by the endocyte technique in order to test the accuracy of the method. Six patients with endometrial carcinoma were diagnosed by curettage and in five of them the cytologic specimens correctly agreed with histology; the other case was an inadequate sample for cytologic diagnosis. Hyperplastic endometrium was found in 14 cases by curettage; only three of them had been detected by cytology. This cytologic technique proved to be satisfactory in diagnosing endometrial cancer but inadequate for detection of premalignant lesions.
Adult↗
Chromosomal instability in Streptomyces glaucescens: mapping of streptomycin-sensitive mutants.
Streptomyces glaucescens strain GLAO (=ETH 22794) produces hydroxystreptomycin and has a high natural resistance to hydroxystreptomycin, dihydrostreptomycin and streptomycin. The wild-type strain gives rise spontaneously to streptomycin-sensitive (StrS-) variants at a frequency of 0 . 2 to 1 . 4%. These mutants lack streptomycin phosphotransferase activity responsible for the wild-type resistance to streptomycin group antibiotics and are unable to produce detectable amounts of hydroxystreptomycin. Mapping experiments showed that the strS marker lies between the chromosomal markers lys-2 and ura-3 on the linkage map of S. glaucescens. The molecular basis for instability of this marker is as yet unknown.
Alleles↗
Bombesin-induced tachyphylaxis markedly enhances gastrin response to a meal.
This study was designed to determine whether a bombesinlike peptide mediated the gastrin response to food. Tachyphylaxis of gastrin release was induced in six dogs by prolonged infusion of bombesin (500 ng X kg-1 X h-1) before ingestion of a meal. An impaired postprandial gastrin response during bombesin tachyphylaxis would be indirect evidence that a bombesinlike peptide mediated the gastrin response to food. Serum gastrin concentrations peaked (74 +/- 18 pM) 1 h after commencement of the bombesin infusion and then fell significantly (P less than 0.01), reaching a nadir of 15 +/- 1 pM at 4 h. Dogs were then fed the standard meal (15 g/kg Prime dog food), and the serum gastrin response was compared with that observed in response to the meal ingested during saline infusion. There was sixfold enhancement (P less than 0.01) of meal-stimulated gastrin release during bombesin infusion compared with saline infusion. Stopping the bombesin infusion before ingestion of the meal still resulted in significant (P less than 0.05) enhancement of the meal response. Although pancreatic polypeptide responses to bombesin also exhibited tachyphylaxis, prolonged infusion of bombesin did not enhance the pancreatic polypeptide response to food. We conclude that a bombesinlike peptide does not mediate the gastrin response to food in dog. We speculate that bombesin stimulates both secretion and synthesis of gastrin but that only secretion is subject to tachyphylaxis. The enlarged secretory pool produces an enhanced response when the G cell is exposed to stimulants other than bombesin.
Animals↗
Lipase-induced alterations of fatty acid synthesis by subcellular fractions from germinating pea (Pisum sativum L.).
1. The effect of exogenous lipases on fatty acid synthesis from [14C]malonyl-CoA by the microsomal and soluble fractions from germinating peas was studied. 2. Addition of phospholipase A2 or the lipase from Rhizopus arrhizus had no effect on total fatty acid synthesis by the soluble fraction but caused severe inhibition of that by the microsomal fraction. 3. The addition of enzymes with phospholipase activity particularly inhibited the microsomal stearate elongase. 4. Control studies indicated that the phospholipase-induced inhibition of fatty acid synthesis was due to the location of fatty acid synthetase, palmitate elongase and stearate elongase on the outside of the microsomal vesicles. 5. Experiments with a trypsin-like proteinase showed that approximately half the microsomal fatty acid synthesis was resistant to proteolysis. 6. Although addition of exogenous phospholipases had no effect on total fatty acid synthesis by the soluble fraction, it did increase alpha-hydroxylation of newly-formed palmitate and stearate. 7. The results provide further evidence for differences between the soluble and particulate fatty acid synthetase and palmitate elongase activities of germinating pea.
Fabaceae↗
Intramuscular variation of fiber types in the brachial biceps and the lateral vastus muscles of elderly men: how representative is a small biopsy sample?
The aim of the study was to investigate the reliability of the distribution of muscle fiber types determined in small fragments of human skeletal muscle. Fiber-type distribution was analyzed in small areas, equivalent to a needle biopsy in size, and in large areas, at nine sites of the brachial biceps (BB) and the lateral vastus (LV) muscles obtained at autopsy from five elderly subjects. It was concluded that in the BB the site of a biopsy should be well defined, since the incidence of fiber types varied systematically. In the LV the biopsy should be large to permit a reliable estimate of the incidence of fiber types; with the needle technique, repeated sampling may be necessary. Small samples are not suited for the analysis of fiber type grouping.
Aged↗
Detection/discrimination in the long-wavelength pathways.
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Color Perception↗
Sex differences in cardiac responses to successive apnea periods.
Cardiac response to breath-holding is generally described as a bradycardia, which is explained by a two-fold mechanism involving the pulmonary mechanoreceptors and the arterial chemoreceptors. This study was conducted to determine the cardiac effects of five successive apnea periods separated by 1 min of free ventilation (FV). Heart rate (HR) and ventilation (V, VT, f) were measured during this protocol in 12 young subjects (6 men, 6 women). Ventilatory responses during FV periods were similar in both sexes, but HR responses were different during the apnea periods. The mean exhibited a bradycardia and the women a tachycardia. Although the statistical significance of the results was weak, they showed a clear tendency which was interpreted as differences in central cardioventilatory interactions. Sex difference in the cardiac consequences of static work from respiratory muscle is also evoked.
Adult↗
Products of fatty acid synthesis by a particulate fraction from germinating pea (Pisum sativum L.).
The synthesis of lipids and acyl thioesters was studied in microsomal preparations from germinating pea (Pisum sativum cv. Feltham First) seeds. Under conditions of maximal synthesis (in the presence of exogenous acyl-carrier protein) acyl-acyl-carrier proteins accounted for about half the total incorporation from [14C]malonyl-CoA. Decreasing the concentrations of exogenous acyl-carrier protein lowered the overall synthesis of fatty acids by decreasing, almost exclusively, the radioactivity associated with acyl-acyl-carrier proteins. A time-course experiment showed that acyl-acyl-carrier proteins accumulated most of the radioactive label at the beginning of the incubation but, eventually, the amount of radioactivity in that fraction decreased, while a simultaneous increase in the acyl-CoA and lipid fractions was noticed. Addition of exogenous CoA (1 mM) produced a decrease of total incorporation, but an increase in the radioactivity incorporated into acyl-CoA. The microsomal preparations synthesized saturated fatty acids up to C20, including significant proportions of pentadecanoic acid and heptadecanoic acid. Synthesis of these 'odd-chain' fatty acids only took place in the microsomal fraction. In contrast, when the 18,000g supernatant (containing the microsomal and soluble fractions) was incubated with [14C]malonyl-CoA, the radioactive fatty acid and acyl classes closely resembled the patterns produced by germinating in the presence of [14C]acetate in vivo. The results are discussed in relation to the role of acyl thioesters in the biosynthesis of plant lipids.
Fabaceae↗
Sexual and postural differences in cardioventilatory responses during and after breath holding at rest.
Twelve subjects (six men, six women) were studied in resting conditions for simple breath holding (BH) in either the supine or upright position. Ventilation (VT, V, fr) heart rate (fc) and arterial blood pressure (ABP) were recorded or measured in steady state and then transiently during BH and its recovery. Each subject performed seven HB in the supine position and two in the upright position. Several criteria were used for fc data analysis. During BH, in either the supine or upright position, no change in heart rate was observed, but subjects taken individually may exhibit some significant cardiac responses (tachycardia or bradycardia) for all the tests. In contrast, an increase in mean ABP is always observed, with different patterns in males and females. The upright position allows the responses to be greater, more rapid and significant. As a general rule, males have larger and slower responses than females. After BH, there is a ventilatory cost of apnea which is more important in males. However the delay in repayment of the ventilatory deficit observed during BH is very short (about 40 s): ventilatory and cardiac recovery are complete within 120 s. The results support the ideas that, (1) cardiac responses during BH are dependent on pulmonary physical conditions and metabolic levels before BH, (2) cardiac changes during recovery are, at least in great part, due to the concomitant hyperventilation.
Adult↗
[Atypical form of cutaneous mastocytosis].
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Child↗
Sex differences in the sympatho-adrenal response to isometric exercise.
The effects on heart rate, blood pressure, and plasma catecholamines (epinephrine, norepinephrine, dopamine) of sustained isometric contraction (SIC) were studied in six women and nine men. Each subject held a tension equivalent to 30% of maximal handgrip strength until exhaustion. There were no significant differences between women and men in the duration of handgrip. Rise of heart rate and blood pressure were similar for women and men. Considering the absolute plasma levels of each catecholamine, no sex differences was observed at rest and at any time during SIC, except for epinephrine whose concentration was higher in men at first min of SIC. On the other hand, women and men exhibited different adrenergic patterns in response to SIC: in the first min of exercise the plasma level of the three catecholamines increased in men whereas for women plasma catecholamines levels were essentially unaffected. Thus, epinephrine seems to play a minor role in the regulation of heart rate and blood pressure during SIC for women. Another interesting result of our study is that SIC is able to induce an increase in dopamine plasma level for women as well as for men.
Adult↗
[Effect of the treatments preceding porcelain baking on the strength of the ceramic-metal bond].
The influence of various prefiring treatments of the metallic structure on the metal-ceramic bond strength has been shown for a gold-platinum ceramic alloys. Using analytical techniques with a high sensitivity, it has been possible to show that indium accumulates considerably on and below the metallic surface and that a subsequent sand blasting or acid pickling (hot diluted sulfuric acid) brings the indium level down to the initial value of the alloy. Changes in the resulting mean coefficient of thermal expansion have been computed and verified experimentally. They have then been correlated with the mechanical behavior of the tested metal-porcelain bonds. It has thus been shown that a preliminary oxidation in the air, followed by a hot acid pickling, is the best prefiring procedure. The superficial indium concentration is more homogeneous and closer to the initial content and the bond strength thus obtained is among the highest, with the lowest dispersion. This procedure enables to enhance the fiability on the porcelain-baked-to-metal technique and to increase the safety margin of the bond itself.
Dental Alloys↗
Physiological effects of dynamic work on a bicycle ergometer combined with different types of static contraction.
The effects on heart rate, oxygen uptake, and pulmonary ventilation of muscular exercises, including both dynamic contractions, either simple or combined, were studied in 4 male subjects, aged 21 to 23 years. The dynamic work consisted in cycling on an ergometric bicycle at three power levels: 40, 80, and 100 W. The static work consisted in pushing against, pulling and holding with the arms a 6, 9, 12, or 18 kg load. The physiological effects are expressed as cardiac cost (delta HR), oxygen cost (delta VO2) and ventilation cost (delta V). The physiological cost of the combined work increases according to the cycling power and to the isometric load developed. A statistical analysis shows that the costs of combined work are not different from the sum of the costs of the static and dynamic contractions measured separately. Thus, the physiological responses to the combinations investigated are of an additive type.
Adult↗