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Biomedical subjects

H Martin

Publications and source records attributed to H Martin.

At least 361 records · Page 20Linked to original sources

[Pulse cytophotometrical investigations about the resistance of DNA against acid hydrolysis influenced by ageing and cortisol (author's transl)].

The resistance of nuclear chromatin against acid hydrolysis with hydrochloric acid was studied in cell nuclei of different organs from young and old rats and after application of cortisol. Suspensions of cell nuclei from liver, spleen, kidney, heart muscle and mucosa from small intestine were stained with ethidium bromide without and after hydrolysis. The relative fluorescence intensity (FI) of every pair was measured by flow through cytophotometry. Always the FI of the diploid peaks of the hydrolysed samples was diminished. The resistance against hydrolysis was greater in old animals than in young. After application of cortisol in vivo in all organs, except in the liver, the resistance against hydrolysis was increased. Only the nuclei of liver from old animals showed a diminution of resistance after cortisol. It is assumed, that the greater resistance in age is due to the diminished functional ability of the nuclear chromatin. In the most organs, the inhibitory activity of cortisol to the cell metabolism is known, only in the liver cell it stimulates the synthesis of RNA and protein. This is in agreement with our findings.

Aging↗

Scanning electron microscopy of the third ventricular floor of the rat.

By utilizing a horizontal dissection technique the entire floor of the third ventricle has been examined. When viewed in toto the ventricular floor was seen to have an hourglass shape with the supraoptic and infundibular recesses equalling the widened portions. Consistent regional differnces were also noted. The rostral half of the floor was densely ciliated while the caudal portion, containing ependymal elements of the underlying median emience, possessed few cilia. The ciliated cells ended in an abrupt transition zone located about halfway along the floor. The rostral portion of the infundibular recess had many more apical blebs and microvilli than did the caudal areas. Supraepen dymal cells of both the phagocyte-like and neuron-like variety were observed in all of the animals examined. In some animals, complex, branching, interconnecting networks of fine calibered fibers interconnected neuron-like cells that occurred singly and occasionally in clusters. Female rats examined at all phases of the estrus cycle demonstrated no cyclic alterations of the ependymal surface.

Animals↗

Coexisting right and left hypertrophic subvalvular stenosis and fixed left ventricular outflow obstruction due to aortic valve stenosis.

A case of fixed left ventricular outflow tract obstruction due to aortic valve stenosis coexisting with right- and left-sided subvalvular hypertrophic stenosis is documented with hemodynamic data, angiograms, echocardiograms and findings at surgery. Histologic examination of the septal muscle with light and electron microscopy revealed hypertrophy of the muscle but none of the characteristics of idiopathic hypertrophic subaortic stenosis. Septal hypertrophy with subvalvular obstruction can occur secondary to left ventricular pressure overload due to fixed left ventricular outflow tract obstruction and is not always the chance occurrence of two separate diseases.

Aged↗

Total blood washout and exchange. A valuable tool in acute hepatic coma and Reye's syndrome.

Total body washout (TBW) was accomplished thirteen times in twelve patients, with response in five and survival in three. TBW can be done without apparent harm to patients and is less laborious and more rapidly effective than repeated exchange transfusion. Early application of TBW in stage III to stage IV hepatic coma may increase survival and possibly prevent progression of metabolic derangements. Patients with stage III to IV Reye's syndrome probably should have TBW promptly, without time-consuming attempts at exchange transfusion. Based on our experience, further application of TBW is warranted in coma due to acute hepatic failure and stage III to IV Reye's syndrome.

Adolescent↗

Toxicity from tea ingestion in an infant: a computer simulation analysis.

A seven-week-old infant presented with tonic posturing and nervous irritability after concentrated tea ingestion. The tea was analyzed and found to contain caffeine, a methylxanthine central nervous system stimulant. With the aid of a computer, projected blood levels were calculated over a thirty-hour time period and comared to the infant's clinical status. It is recommended that beverages containing xanthines be given to infants and small children with caution.

Caffeine↗

Metabolism of the apoproteins in pulmonary surfactant.

Two proteins having nominal molecular weights of 35,000 and 10,000 daltons are found in pulmonary surfactant. Although experiments on their immunological properties suggest that they share antigenic determinants, their metabolic relationship is unknown. To study this question we injected [14C]palmitic acid or L-[3H]leucine into the femoral vein of 59 puppies. We killed the animals 30 min to 68 h after injection and purified surface-active material from the endobronchial lavage fluid. We isolated the 35,000 apoprotein, the 10,000 apoprotein, and the saturated phosphatidylcholines in surfactant and measured their specific activities at various times after injection. We found that the 35,000 apoprotein appears in alveolar surfactant with the same time course as saturated phosphatidylcholine but is cleared more rapidly than is the lipid. The specific activity of the 10,000 apoprotein reaches a maximum after that seen for the 35,000 apoprotein and decays with the same turnover time as that of the lipid. The kinetic data suggest that the 10,000 apoprotein is a metabolic product of the 35,000 apoprotein. They are not consistent with the possibility that the 10,000 apoprotein is an artifact of nonspecific degradation during preparation.

Amino Acids↗