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Biomedical subjects

M T Lin

Publications and source records attributed to M T Lin.

At least 379 records · Page 21Linked to original sources

Oral salbutamol therapy of asthma in young children.

Twenty-one young asthmatics, 2-6 years of age (mean 4 years), were given an open trial of salbutamol syrup to assess its safety. Each patient was given 1 mg, then 2 mg, q8h for two weeks. Only one patient experienced side-effects and this was at the 2 mg dose. It is concluded that salbutamol syrup is safe at a dose of 1 to 2 mg q8h for the asthmatic children in this age group.

Administration, Oral↗

Brain monoamines act through the prostaglandin release to influence the body temperature.

In the present study, the thermal responses induced by intraventicular administration of pyrogen prostaglandin E1, the brain monoamines norepinephrine and serotonin, and the antipyretic sodium acetylsalicylate (aspirin) were measured in conscious rabbits to assess the possible involvement of these substances in fever production. The body temperatures, metabolic rate, respiratory evaporative heat loss and vasomotor activity in response to the administration of these drugs were measured. The results showed that sodium acetylsalicylate, an inhibitor of prostaglandin synthetase, antagonizes the norepinephrine induced fever but not the prostaglandin fever. The data also showed that the serotonin induced hypothermia was reversed by prostaglandin administration. Thus, the fact strongly suggest that the prostaglandin E1 serves as a fever-prducing mediator in the central nervous system. Also, the norepinephrine fever and serotonin hpyothermia, respectively, may be associated with an increase and a decrease in prostaglandin synthesis in the brain.

Animals↗

Surface area of the Taiwan monkey.

The surface areas of seven Taiwan monkeys were determined by applying the plastic tape on sheard skin. The equation, surface area (cm2) = 13.5 (body weight (g) 2/3 was found to describe adequately the relationship between the body weight and body surface area of the Taiwan monkeys ranging from 2.58 to 7.5 kg. The relative distribution of total body surface area among four regions selected fro the calculation of a mean skin temperature in the Taiwan monkeys was also determined. From the data a simple equation for calculating the mean skin temperature (Tsk) of the Taiwan monkeys was derived using four measured skin temperatures. The equation is Tsk = 043.Ttrunk+0.36Tlimb+0.07Ttail+0.14Tfoot.

Animals↗

Hypothermic action of chlorpromazine in monkeys.

1 In the conscious monkey (Macaca cyclopis) intravenous administration of chlorpromazine 0.1-8.0 mg/kg produced a fall of rectal temperature of 0.3 to 3.5 degrees C after a latency of 3.5 to 10.8 minutes. The course of hypothermia lasted from 125 to 600 min or more. 2 Direct injection of chlorpromazine 100-800 mug into the lateral or fourth cerebral ventricle produced a similar fall of 0.3 to 2.0 degrees C but with shorter latency (2 to 3.5 min) and with a duration of 94 to 375 minutes. 3 Two distinct structures in the brain stem, namely, the preoptic anterior hypothalamus (POAH) and medulla oblongata, responded to direct injection of chlorpromazine 200 mug. The sensitivity was slightly higher in the POAH than in the medulla. Structures in between were not sensitive. 4 The results suggest that chlorpromazine works principally through the central nervous system, i.e. the POAH and medulla oblongata, to mediate its hypothermic effect.

Animals↗

High Production of Kojic Acid Crystals by Aspergillus parasiticus UNBF A12 in Liquid Medium.

The crystalline compound produced in large quantity in liquid medium by Aspergillus parasiticus UNBF A12, a high aflatoxin-producing strain isolated from the air in the Federal District of Brazil, was identified as kojic acid. The effect of pH on the production of crystalline kojic acid and aflatoxins by the strain was studied. Fourteen single spore isolates were evaluated for their capacity to produce kojic acid crystals and aflatoxins.

Journal Article↗

Effects of sodium acetylsalicylate on body temperature of monkeys under heat exposure.

Exposure of Taiwan monkeys to 38 degrees C ambient temperature caused: a) raised body temperature, b) restlessness and struggling, c) increased evaporative heat loss and d) increase in tail skin temperature. After the administration of sodium acetylsalicylate, 100 to 250 mg/kg intraperitoneally or 4 to 15 mg intracerebroventricularly (third ventricle) the same heat load caused: a) less increase in body temperature, b) no restlessness or struggling, c) an initially higher rate of evaporative heat loss and d) higher tail skin temperature. Larger doses of acetylsalicylate caused greater antihyperthermic effects. Intracerebroventricular injection was more effective than the intraperitoneal route. These data show that acetylsalicylate improved tolerance of animals to external heat loads. The magnitude of body temperature elevation during heat exposure was reduced in the presence of acetylsalicylate by activation of heat-dissipating mechanisms, presumably through the central nervous system.

Animals↗

Ultrastructure, steroidogenic potential, and energy metabolism of the Snell adrenocortical carcinoma 494. A comparison with normal adrenocortical tissue.

Electron microscope studies were carried out with the adrenocortical carcinoma 494 and normal adrenal cortex tissue. The mitochondria of the tumor cells showed marked differences when compared with mitochondria from fasciculata cells of the normal adrenal cortex. These differences were primarily related to mitochondrial number and crista structure. Corticosterone production in isolated tumor cells was extremely low and neither ACTH nor dibutyryl cyclic AMP had any stimulatory effect. Normal adrenal cells showed at least a tenfold increase under identical conditions. In the presence of corticosteroid precursors the amount of corticosterone produced by the tumor cells was much less than that produced by normal cells. The results indicate a reduced capacity for 11beta-hydroxylation in the tumor mitochondria and a possible reduced capacity for biosynthetic steps before the 11beta-hydroxylation reaction. Glycolysis in isolated tumor cells was also lower than in normal cells. Isolated tumor mitochondria oxidized succinate normally with a good degree of coupling with phosphorylation. However, unlike normal adrenal mitochondria, the tumor mitochondria showed little or no oxygen uptake with other Krebs cycle substrates. These data suggest that the tumor mitochondria may be lacking in the flavoprotein dehydrogenases responsible for the oxidation of NADH and NADPH, although other components of the respiratory chain may be intact.

Adrenal Cortex↗

Effects of thermal stimulation of medulla oblongata and spinal cord on decerebrate rabbits.

1. Changes of rectal and ear temperatures, and respiratory and heart rates, during external thermal stress and during thermal displacement of the medulla oblongata and spinal cord have been investigated in rabbits, before and after decerebration, with ether inhalation only during the operation.2. Abrupt exposure of the intact animals to heat (35 degrees C) or cold (5 degrees C) produced appropriate thermoregulatory adjustments such as vasodilatation or vasoconstriction of the ear skin, and increase or decrease of respiratory frequency with little change in rectal temperature. After decerebration, these responses to heat and cold were reduced and rectal temperature was moderately altered.3. In intact animals, heating (42-43 degrees C) and cooling (32-33 degrees C) the medulla and spinal cord also produced appropriate thermoregulatory vasomotor and respiratory responses, although these were smaller than those caused by ambient heating and cooling. Heating these structures also produced bradycardia and cooling tachycardia. In addition, shivering-like movements over extremities and trunks or jaws were elicited, respectively, during spinal or medullary cooling. None of these responses was altered after decerebration.4. These results suggest that while the hypothalamus may be the principal site of thermoregulation, some independent but less powerful thermoregulatory structures exist in the medulla oblongata and spinal cord. Thermal responses to stimulating the latter structures are not results of afferent activation of the hypothalamic mechanism.

Animals↗

Effects of heating and cooling the spinal cord and medulla oblongata on thermoregulation in monkeys.

1. In the unanaesthetized monkey (Macaca cyclopis), heating the spinal cord or the medulla oblongata from 38 to 42-43 degrees C produced subcutaneous vasodilatation, respiratory acceleration (frequently interrupted with a period of apnoea in the medullary experiment), bradycardia and hypotension. The animal became drowsy and had a slight decrease of body temperature. Heating the medulla oblongata often induced retching and/or emesis.2. Cooling the spinal cord or medulla oblongata from 38 to 32-33 degrees C produced subcutaneous vasoconstriction, slower respiration, tachycardia and hypertension. The animal became restless and had a slight increase of body temperature. Cooling the spinal cord induced shivering of the four limbs, while cooling the medulla oblongata induced only shivering of the jaws.3. The effects of heating or cooling of the spinal cord or the medulla oblongata were antagonized by simultaneous application of temperature displacement of the opposite nature in the same areas or vice versa.4. The data suggest that some thermosensitive elements possibly responsible for thermoregulation reside in the spinal cord and the medulla oblongata.

Animals↗