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Biomedical subjects

H Mentzel

Publications and source records attributed to H Mentzel.

At least 37 records · Page 2Linked to original sources
PubMed1985

Point mutational analysis of the Xenopus laevis 5S gene promoter.

We have introduced C to T transitions into GC and CG base pairs of the Xenopus laevis somatic 5S gene coding region and its 5' flank in order to analyse their effects on transcription activity and regulation. These studies allow us to differentiate between the two promoter elements and their spacer, within the internal control region. Mutations within the 5' element which dissent from the corresponding tRNA consensus sequence reduce transcription activity substantially without significantly affecting transcription factor (TF) III A binding. Mutations in the spacer region have no pronounced effect on transcription. The 3' promoter element is found to extend to position 97, since mutations in this region interfere with transcription activity. This may be, at least partially, attributable to a reduced competition strength for TF III A.

Animals↗
PubMed1983

[Mortality and neurological morbidity in prematurely born infants and low birthweight infants born at term].

In a follow-up study the fate and development of 245 prematures with a birthweight below 1,500 g and of 230 infants with a birth weight of 1,501-2,500 g are reported. The mortality of infants with a birthweight below 1,500 g was 29.8%, in the group of infants with higher birthweights 9.1%. The frequency of severe neurological sequelae in infants with very low birthweight was 8.2%, in the other group of infants 3.5%. Minor handicaps and developmental abnormalities were found in a frequency of 12.2%, and 4.7% respectively. These results meet the present international standard in centers for perinatal medicine. Prospective investigations are mandatory to recognize causal factors for later severe handicaps.

Attention Deficit Disorder with Hyperactivity↗
PubMed1982

Morphologic aspects of Goldblatt hypertension in a newborn infant.

Hypertension (210 mm Hg), hyponatremia, hypochloremia, and hypokalemia were observed in an 11-day-old infant. After electrolyte repletion, blood pressure rose to 320 mm Hg in spite of administration of antihypertensive drugs. The child died of a massive cerebral hemorrhage on the 17th day of life. At autopsy, the left renal artery was partially thrombosed and the left kidney partially infarcted. The glomeruli in the preserved cortical areas were of normal size; the juxtaglomerular apparatuses markedly enlarged. The blood vessels were inconspicuous. Enlarged glomeruli, multiple ruptures in the mesangium, ectactic glomerular capillaries, and fragile capillary walls were found in the nonconstricted right kidney. Fibrinoid necrosis with occasional fibrin thrombi in the lumina was present in the arterioles. Pronounced intimal edema with fragmented cells and monocytes embedded in the intima were observed in the interlobular and larger arteries. The histologic findings in the blood vessels of the nonconstricted kidney resembled those found in the hemolytic-uremic syndrome (Gasser's syndrome).

Hemolytic-Uremic Syndrome↗
PubMed1981

Favored incorporation of tubercidin in poly(adenylic, 7-deazadenylic acids) and their function as messenger ribonucleic acids in protein synthesis.

The following polynucleotides containing the antibiotic tubercidin (Tu; 4-amino-7-beta-D-ribofuranosylpyrrolo-[2,3-d]pyrimidine) were enzymatically synthesized by polymerization of adenosine 5'-diphosphate-tubercidin 5'-diphosphate mixtures with polynucleotide phosphorylase: poly(A2,Tu), poly(A,Tu2), and poly(Tu). The incorporation of the antibiotic was favored by the enzyme. The polymers are compared to poly(adenylic acid) [poly(A)] with respect to their structure, conformation, and ability to direct polylysine synthesis in a ribosome-dependent protein synthesis system. From physical data (thermal melting, NMR, and circular dichroism) it is concluded that tubercidin destabilizes the structure of the polynucleotide chain and that this may be due to an altered polarization of the nucleobases and their enhanced rotation around the N-glycosylic bond. Since there is an apparent correlation between thermal unfolding of the polymers and their ability to mediate polylysine synthesis, it is suggested that partial destacking of the messenger ribonucleic acid favors its binding to the ribosome and/or its ability to enhance codon-anticodon-specific protein synthesis.

Circular Dichroism↗
PubMed1981

[Necrotizing enterocolitis (NEC) - pathogenesis and therapy (author's transl)].

The clinical courses in 39 children with NEC were studied to answer questions about pathogeny and the indication for surgical treatment. Anamnestic, clinical and hematological findings show an ischemia to be the "conditio sine qua non". Disseminated intravascular coagulation does not seem to be the primary cause of the disease. Whether bacterial infections of the intestinal wall are of importance in the pathogeny cannot sufficiently be proven on the available findings. The clinical symptoms, the number of platelets and the level of serum-sodium make it possible to classify NEC in four stages with typical morphologic appearance. The results of an early and of a late treatment by operation are compared and it is deduced that the best moment for surgical intervention will be the change from stage II to stage III. Symptoms of stages II/III are the progressive clinical course with increasing intestinal bleeding, edema of the abdominal wall and scrotum, thrombopenia and low sodium level.

Child↗
PubMed1980

Sodium loss as leading symptom of renovascular hypertension in the newborn.

The history of a newborn developing severe renin-induced hypertension is reported. A thrombotic occlusion of the lower a.abdominalis with an ascending thrombus into the left a.renalis caused hypertension according to the two-kidney-one-clip hypertension. High pressure diuresis induced weight loss by polyuria, hyponatremia and hypokalemia by severe renal salt losses. The vicious circle of malignant hypertension was initiated by sodium losses, not sufficiently recompleted by therapy. The full picture of an acute hypertensive renal damage was seen at autopsy in the unclamped kidney.

Humans↗
PubMed1978

[Results of intensive care and intensive therapy of very low birth-weight infants (author's transl)].

Newborns of less than 1500 g birth-weight are thought to be especially at risk with regard to their psychomotor development. Among 71 such infants admitted to the University Childrens Clinic, Tübingen, in 1974-1975, 43 survived (38% mortality). All but two of them were followed serially and assessed for their psychomotor development. Five were found to be abnormal (12%), three of them most probably having sustained CNS damage prenatally.

Child, Preschool↗