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Biomedical subjects

A Conrad

Publications and source records attributed to A Conrad.

59 records · Page 4Linked to original sources
PubMed1980

[Morphology of cavernous transformation of the portal vein (author's transl)].

Morphology of cavernous transformation of the portal vein is discussed on the basis of 5 case reports. On histological examination it can be shown, that in these cases a combination is present of chronic recanalized portal vein thrombosis and formation of paraportal hepatopetal collaterals. Formation of collaterals starts with new growth of primitive sinusoidal vessels originating from the portal vein and protruding into the paraportal tissue. Later on these vessels exhibit increasing venous differentiation up to the point of formation of varices very late in the development. The meaning of the veins of Sappey is discussed in regard to collateral circulation and to the formation of the new vessels mentioned.

Adult↗
PubMed1977

Prevention by specific perceptual remediation for vulnerable first-graders. Controlled study and follow-up of lasting effects.

In a pretest-posttest design with two matched control groups, 86 first-graders screened as vulnerable to academic failure and behavioral decompensation were each assigned to one of three groups: (1) channel-specific perceptual stimulation, (2) regular academic tutoring (contact controls), or (3) no contact. On most measures, including perceptual and achievement tests and behavior ratings by teachers, group 1 showed more improvement than either of the control groups. Several of these differences were significant (P less than .05, two-tailed). In general, the two control groups came closer to each other than to group 1. With no further intervention, follow-up one year later showed more dramatic significance. On every measure, group 1's improvement surpassed that of the control groups, and diverged from them even more than at posttest; this divergence was significant on most measures. Group 1 improved significantly (P less than .05 to P less than .01) in reading, IQ, and three behavior scales, while both control groups showed only deterioration on these measures. Group 1 gained five IQ points on the Wechsler Intelligence Scale for Children, while the controls lost five. On the Davids Scale, group 1 improved significantly (P less than .01) to "probably not hyperkinetic," while both control groups deteriorated to "probably hyperkinetic." The hypothesized mechanism of group 1's behavioral superiority at follow-up was its significant (P less than 0.1) reading improvement, with secondary emotional benefits.

Adolescent↗
PubMedDate not supplied

Influence of mitochondrial creatine kinase on the mitochondrial/extramitochondrial distribution of high energy phosphates in muscle tissue: evidence for a leak in the creatine shuttle.

The influence of mitochondrial creatine kinase on subcellular high energy systems has been investigated using isolated rat heart mitochondria, mitoplasts and intact heart and skeletal muscle tissue. In isolated mitochondria, the creatine kinase is functionally coupled to oxidative phosphorylation at active respiratory chain, so that it catalyses the formation of creatine phosphate against its thermodynamic equilibrium. Therefore the mass action ratio is shifted from the equilibrium ratio to lower values. At inhibited respiration, it is close to the equilibrium value, irrespective of the mechanism of the inhibition. The same results were obtained for mitoplasts under conditions where the mitochondrial creatine kinase is still associated with the inner membrane. In intact tissue increasing amounts of creatine phosphate are found in the mitochondrial compartment when respiration and/or muscle work are increased. It is suggested that at high rates of oxidative phosphorylation creatine phosphate is accumulated in the intermembrane space due to the high activity of mitochondrial creatine kinase and the restricted permeability of reactants into the extramitochondrial space. A certain amount of this creatine phosphate 'leaks' into the mitochondrial matrix. This leak is confirmed in isolated rat heart mitochondria where creatine phosphate is taken up when it is generated by the mitochondrial creatine kinase reaction. At inhibited creatine kinase, external creatine phosphate is not taken up. Likewise, mitoplasts only take up creatine phosphate when creatine kinase is still associated with the inner membrane. Both findings indicate that uptake is dependent on the functional active creatine kinase coupled to oxidative phosphorylation. Creatine phosphate uptake into mitochondria is inhibited with carboxyatractyloside.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMedDate not supplied

Correlation of serum HCV RNA and alanine aminotransferase levels in chronic hepatitis C patients during treatment with ribavirin.

To evaluate the effect of ribavirin on serum hepatitis C virus (HCV) RNA and alanine aminotransferase (ALT) levels, 22 patients with chronic HCV infection were treated with oral ribavirin 1200 mg daily in three divided doses for 4 weeks. At the end of 4 weeks treatment, the serum ALT decreased in all but one patient and became normal in three individuals. The mean pretreatment serum ALT was reduced significantly from 193 +/- 45 i.u./L to 95 +/- 16 i.u./L after 4 weeks therapy (P = 0.009). However, 8 weeks after cessation of treatment, the serum ALT rose to a mean value of 154 +/- 21 i.u./L. The mean pretreatment serum HCV RNA was not significantly decreased at the end of 4 weeks treatment (7.0 x 10(5) vs. 4.1 x 10(5) copies/mL, P > 0.05). However, serum HCV RNA levels were decreased in 12 and increased in 10 patients at the end of 4 weeks therapy. Eight weeks after cessation of therapy, the serum HCV RNA of 22 patients rose to a mean value of 4.9 +/- 10(5) copies/mL. Six patients who continued to have elevated serum ALT and positive HCV RNA after the initial 4 weeks treatment received oral ribavirin at the same dosage for an additional 24 weeks. The serum ALT again decreased in all six patients during therapy, but rose to pretreatment values by 8 weeks after cessation of the treatment. In addition, no significant changes were noted in the mean serum HCV RNA levels during and after 24 weeks of ribavirin therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗