Somatostatin immunoreactive C cells in thyroid glands from various mammalia species

The relative distribution of somatostatin- and calcitonin-containing cells in thyroid glands from various mammalian species was investigated by immunoperoxidase staining, and the concentration of immunoreactive somatostatin by radioimmunoassay. In the thyroid glands of guinea pigs and rabbits, most of the calcitonin cells were also immunoreactive to the somatostatin antiserum, and high concentration of immunoreactive somatostatin was obtained. On the other hand, in the thyroids of other animal species—rats, dogs, pigs, cows, goats, cats, monkeys, mice, and hamsters—only a few C cells revealed the immunoreaction for somatostatin, and the concentration of somatostatin was low. In all animal species studied, the somatostatin was present in the same cells that contain calcitonin, though in guinea pigs and rats there were some C cells containing a large number of reaction products for somatostatin but very few for calcitonin. Thus, it was concluded that there was a considerable variation in somatostatin immunoreactivity of thyroid C cells from species to species.     

A Simplified Master's Two-step Test for Preschool Children

To investigate the usefulness of a simplified Master's two step test (s-MTT) for preschool children aged 4–6, s-MTT was carried out in our pediatric cardiology clinic using a new stair and connector for joining the leads from each child to the ECG machine. The subjects were 21 children with Kawasaki disease without coronary involvement and four children with arrhythmias. The treadmill exercise test (TET) was done on the same day to compare the exercise load of s-MTT with that of TET. Oxygen uptake during s-MTT was also examined using another group consisting of eight outpatients. There were no differences in indices such as peak heart rate (HR), HR immediately after exercise, and performance ratio between the outpatients in this study and kindergarteners in the preliminary report, The proportions of peak HR and HR immediately after exercise in s-MTT to those in TET were 91.1 ± 7.9 (mean ± SD)% and 91.1 ± 8.6%, respectively. The average oxygen uptake of the eight outpatients in s-M'IT was 23.2 ± 4.1 ml/min/kg. These studies suggest that the simplified MTT is useful as a screening test, because it can be done for all children aged 4–6 in any laboratory.     

Hypergravity induced prolactin surge in female rats

Acute initial exposure to hypergravity (HG) was previously found to induce prolonged diestrous in rats, which was followed by return to normal estrous cycling upon more prolonged exposure to continuous HG. Bromergocryptine was found to prevent this prolonged diestrous. In this study we found that in female rats 20 h of 3.14 G exposure (D-1 1200 h until D-2 0800 h) can induce prolactin surge at D-2 1600 h. Shorter exposure time (8 h), or exposure during a different part of the estrous cycle (19 h: from D-1 0700 h until D-2 0200 h) could not elicit this prolactin surge. Similar exposure of male rats to HG did not alter significantly their prolactin levels. It is possible that the hypothalamus of male and female rats responds differently to stimulation by HG.     

Computer application for respiratory data processing in closed circuit anesthesia

Summary A computerized respiratory monitor system for closed circuit anesthesia is described. The system consists of a mass spectrometer, a hot-wire respiratory flow meter, a microcomputer, a central display and a recorder. Respiratory parameters obtained by the computerized system include O₂ consumption, carbon dioxide production, expiratory minute volume and respiratory rate. Using this system, closed circuit anesthesia was used in eleven surgical patients. Breath by breath value of carbon dioxide production stayed within the normal range during the procedure, though that of oxygen consumption varied markedly. This system allows anesthesiologists to detect, breath by breath, optimal gas flow and metabolic requirement during the closed circuit anesthesia.Closed circuit anesthesia is being used with increasing frequency in recent years. The patient's condition must be monitored continuously during the closed circuit anesthesia to maintain optimal depth of anesthesia and to prevent hypoxia or hypercarbia; however, monitoring of the respiratory gas exchange is difficult. We have developed a computerized respiratory monitor system for the closed circuit anesthesia.     

Ginkgo biloba extract protects brain neurons against oxidative stress induced by hydrogen peroxide

Effect of Ginkgo biloba extract was examined on dissociated rat cerebellar neurons suffering from oxidative stress induced by hydrogen peroxide using a flow cytometer and ethidium bromide. Hydrogen peroxide at a concentration of 3 mM increased the number of neurons stained with ethidium (presumably dead neurons) in a time-dependent manner. Pretreatment of neurons with G. biloba extract (10 μg/ml greatly delayed a time-dependent increase in number of dead neurons during exposure to hydrogen peroxide. It was true, but less effective, in the case of treatment with G. biloba extract immediately or 60 min after start of oxidative stress. Results implicate G. biloba extract as a potential agent in protecting the neurons suffering from oxidative stress induced by hydrogen peroxide.     

RETRACTED ARTICLE: Contractility of fatigued diaphragm is improved by dobutamine

The effects of dobutamine (DOB) on diaphragmatic fatigue were examined in 20 anaesthetized, mechanically ventilated dogs. Animals were divided into two groups: the DOB group (n = 10) and the control group (n = 10). Diaphragmatic fatigue was induced by intermittent supramaximal electric stimulation applied to bilateral phrenic nerves at a frequency of 20 Hz for 30 min. Diaphragmatic contractility was assessed with transdiaphragmatic pressure (Pdi). After diaphragmatic fatigue, Pdi decreased at low-frequency (20 Hz) stimulation (P < 0.05), whereas the decrease was minimal at high-frequency (100 Hz) stimulation. In the DOB group, after producing fatigue, the continuous administration of 10 μg · kg^?1 · min^?1 dobutamine iv for 30 min produced an increased Pdi at both frequencies of stimulation (P < 0.05). The Pdi returned to pre-fatigue values after cessation of dobutamine administration. In the control group, the speed of recovery from fatigue was much slower at low-frequency stimulation. The integrated diaphragmatic electric activity (Edi) in the two groups did not change throughout the experiment at any frequency of stimulation. We conclude that dobutamine improves contractility in fatigued diaphragm.     

Azygos and hemiazygos connections imaged by two-dimensional, and pulsed and color Doppler echocardiography

Identification of the azygos or hemiazygos connection is important in the diagnosis of congenital heart disease, especially in cases of the polysplenia syndrome. Although two-dimensional echocardiographic observation of this anomaly has been reported, the direct visualization of drainage sites is still rather difficult. A method for visualizing the azygos or hemiazygos connection by a combined use of two-dimensional and pulsed and color Doppler echocardiography was reported here. Subjects consisted of 10 patients with the polysplenia syndrome, each of whom had been confirmed as having the azygos or hemiazygos connection; five each of the azygos and hemiazygos types. The transducer was placed over the second intercostal space on the right side for the azygos, and on the left side for hemiazygos connection. The two-dimensional echocardiographic plane was adjusted to visualize the long-axis view of the superior vena cava; the right superior vena cava for the azygos and the left superior vena cava for the hemiazygos connection. The mode of the equipment was changed to color Doppler, and an orange-colored blood flow toward the transducer, draining into the superior vena cava was carefully sought. Finally the pulsed Doppler mode was selected and the sampling volume was set in the orange-colored area. The wave form of the pulsed Doppler echocardiogram of the azygos or hemiazygos vein potentially had two peaks per cardiac cycle, and was modified by respiration. We found azygos or hemiazygos veins coursing from the posterior aspect of the right pulmonary artery in seven of 10 cases by two-dimensional echocardiography alone, while we observed all veins by the additional use of color and pulsed Doppler echocardiography.