PubMed Health⌕ Search

Biomedical subjects

J Menke

Publications and source records attributed to J Menke.

10 recordsLinked to original sources
PubMed1993

Simultaneous influence of blood pressure, PCO2, and PO2 on cerebral blood flow velocity in preterm infants of less than 33 weeks' gestation.

In extremely preterm infants, the protective capacity for cerebral blood flow (CBF) autoregulation may be impaired or absent, which increases the risk for developing cerebral lesions. The purpose of this study was to quantify the simultaneous influence of several vital parameters, such as mean arterial blood pressure (MABP), PCO2, and PO2, on cerebral blood flow velocity (CBFv), which is used as a measure for CBF. In 16 mechanically ventilated infants of < 33 wk gestation, the CBFv in the internal carotid artery was measured every minute for 1 h by a computer-controlled pulsed Doppler device. MABP and transcutaneous PCO2 and PO2 were recorded as well. A multiple linear regression analysis was performed in each patient to determine the individual MABP, PCO2, and PO2 reactivities as a measure for CBF autoregulation. The medians (and ranges) of the whole group were an MABP reactivity of 7.5% (-12.5 to 20.1%) rise in CBFv/1 kPa rise in MABP, a PCO2 reactivity of 32.7% (-8.1 to 79.5%) rise in CBFv/1 kPa rise in PCO2, and a PO2 reactivity of -3.1% (-14.2 to 7.9%) fall in CBFv/1 kPa rise in PO2. In preterm infants, the individual's capacity for MABP-, PCO2-, and PO2-dependent CBF autoregulation can be estimated by means of the present method, even if the vital parameters change simultaneously.

Blood Flow Velocity↗
PubMed1986

Clinical application of DNA analysis in a family with OTC deficiency.

We describe the clinical application of DNA restriction fragment analysis to the genetic evaluation of a family with a child deficient in ornithine transcarbamylase (OTC). The results of protein loading studies and the interpretation of the DNA haplotype profiles for the human OTC gene are reported. DNA restriction fragment analysis may be a reliable technique for the prenatal diagnosis of OTC deficiency and identification of obligate carriers of this gene.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

Heteroduplex analysis of molecular clones of the pathogenic Friend virus complex: Friend murine leukemia virus, Friend mink cell focus-forming virus, and the polycythemia- and anemia-inducing strains of Friend spleen focus-forming virus.

The pathogenic Friend virus complex is of considerable interest in that, although members of this group are genetically related, they differ markedly in biochemical and biological properties. Heteroduplex mapping of molecular clones of the Friend virus complex, which includes the replication-competent ecotropic Friend murine leukemia virus (F-MuLV) and mink cell focus-forming virus (F-MCF) and replication-defective polycythemia- and anemia-inducing strains of spleen focus-forming virus (SFFVp and SFFVa, respectively), was employed to provide insight into the molecular basis of their relationships. In heteroduplexes of F-MuLV X F-MCF, a major substitution of 0.89 kilobases in the env gene of F-MCF was discerned. Heteroduplexes of SFFVp X F-MuLV or F-MCF and SFFVa X F-MuLV or F-MCF showed several major deletions in the pol gene region and a single major deletion in the 3' half of the env gene region of SFFVp and SFFVa. A major substitution of 0.89 kilobases was mapped to the 5' end of the env deletion of SFFVp and SFFVa in heteroduplexes with F-MuLV, similar to that seen in F-MuLV X F-MCF heteroduplexes. In contrast, this env gene region was totally homologous in F-MCF X SFFVp or SFFVa and SFFVp X SFFVa heteroduplexes. Our results suggest that (i) both SFFVp and SFFVa lack part of the env gene at its 3' end, corresponding to the p15(E) coding region, (ii) major deletions occur in the pol and env genes which account for the replication defectiveness of SFFVp and SFFVa, (iii) minor substitutions occur in the gag gene region of SFFVa that are not present in SFFVp, F-MuLV, or F-MCF, (iv) a major substitution exists in the gp70 region of the env gene between F-MuLV and F-MCF that probably accounts for the differences in their host range specificities, (v) this substitution in F-MCF is identical to the gp70 part of the gp52 coding region of SFFVp and SFFVa, and (vi) heteroduplexes to F-MCF show unambiguously that no additional large substitutions are present in SFFVp or SFFVa that could account for differences in their leukemogenicity.

Animals↗
PubMed1976

Theophylline pharmacokinetics in premature infants with apnea.

The pharmacokinetics of theophylline were examined in eight low-birth-weight infants (gestation: 26-32 weeks: birth-weight: 887-1,480 gm), who received the drug for treatment of primary apnea. The drug was assayed by high pressure liquid chromatography. The final dosage was 1 to 3 mg/kg/6 hour at 25 to 37 days of age. At the time, theophylline had a prolonged half-life ranging from 13 to 29 hours, a relatively large volume of distribution of 0.65 to 2.86 1/kg, and a small body clearance of 23 to 68 ml/hr/kg. The extremely slow and variable elimination of theophylline must be considered in treatment of apneic infants. The initial dosage regimen suggested is a loading dose of 6 mg/kg and a maintenance dose of 2 mg/kg/ 12 hours, with adjustments made based on monitoring of the serum concentration and on an increased biotransformation capability as maturation occurs.

Apnea↗