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Biomedical subjects

G Wolf

Publications and source records attributed to G Wolf.

At least 667 records · Page 37Linked to original sources
PubMed1980

The effect of thermal burns on the release of collagenase from corneas of vitamin A--deficient and controls rats.

A mild trauma in the form of a thermal burn was applied to corneas of vitamin A--deficient rats and their pair-fed controls. The control corneas routinely showed rapid re-epithelialization without stromal changes. The corneas of deficient rats recovered more slowly, frequently exhibiting stromal edema, leukoma, and sometimes ulceration. Because collagenase is thought to initiate collagen destruction in corneal ulceration, the relationships among vitamin A status, severity of trauma, and collagenase levels were determine. Mild thermal burns were found to cause corneas from less severely deficient rats to ulcerate rarely but no release increased levels of collagenase, mainly on the first day of culture, as in the case of nonburned, severely deficient rats. Comparable burns of corneas of pair-fed control rats resulted in no ulceration and in very little collagenase release. Severe burns of either pair-fed control or normal rat corneas caused ulceration and collagenase release, but collagenase activity was maximal on the second and third days of culture. Differences in vitamin A status at time of burning gave rise to different patterns of collagenase. By following the development of the vitamin deficiency, it was determined that little active collagenase is released after mild burns of corneas in animals in the pre--weight plateau stage but that much more active enzyme is released when animals are in weight plateau or 5% weight loss stages. Studies of the effect of recovery from vitamin A deficiency on the response to mild thermal burn indicated that the longer the interval between feeding vitamin A and the burn, the lower the postburn level of collagenase in the day 1 medium. Thus it would appear that restitution of vitamin A status decreased the level of active collagenase after the mild thermal burn. The system developed here can be used to study the biochemical basis for ulceration in vitamin A deficiency, and the possibility exists that the ulceration characteristic of keratomalacia in people can be initiated by an environmental trauma.

Animals↗
PubMed1980

Galactosyl transferase activity in rat bladder transitional cell carcinoma lines and in exfoliated cells in urine during carcinogenesis and reversible hyperplasia.

Cultured cells of rat bladder transitional cell carcinoma line AY-27, in suspension, were assayed for galactosyl transferase (GT) by measurement of the transfer of [3H]galactose from uridine diphosphate-[3H]galactose to desialylated ovine submaxillary mucin (OSM-NANA). The assay was optimized with respect to time and to protein, uridine diphosphate galactose, OSM-NANA and Triton X-100 concentrations. This assay was then applied weekly to suspensions of exfoliated bladder cells collected from urines of rats fed the bladder carcinogen N-[4-(5-nitro-2-furyl)-2-thiazolyl]formamide, and of control rats. Increases in activity over controls appeared 42 weeks after feeding the carcinogen, at a stage when bladder tumors were already microinvasive or deeply invasive, and activities at 52 weeks were about 10-fold greater than normal values. In contrast, a bladder cytotoxic agent inducing reversible hyperplasia was injected into rats, and exfoliated cells were collected from urines: these cells showed no greater GT activity than normal. Bladder tumor tissue from a transplanted tumor had the same high specific enzymatic GT activity as exfoliated cells from tumor-bearing rats.

Animals↗
PubMed1980

Identification and metabolic differentiation of rat neurophysins: a microelectrophoretic study.

Proteins of the hypothalamo-neurohypophysial system of the rat were studied by means of a purpose-modified form of microelectrophoresis in the polyacrylamide gradient. The respective shares of neurophysins I, II and III in total neurophysin were found to be 58 +/- 16, 24 +/- 5 and 18 +/- 6% in HCl extracts and 48 +/- 7, 30 +/- 7 and 23 +/- 5% in aqueous extracts. In particular, neurophysin I was absent in homozygous Brattleboro rats, with no evidence being obtained as to aberrant neurophysins. Approximately equal neurophysin shares were observed for heterozygous Brattleboro rats. Using perfused material, one of the fractions occurring in neurohypophysial extracts was clearly identified as serum albumin. The electropherograms of aqueous neurohypophysial extracts revealed up to 43 protein fractions. Comparison with extracts from the median eminence, the nuclei of the hypothalamo-neurohyophysial system and other hypothalamic regions, as well as the results of incubation experiments distinguished one fraction as a possible candidate for the hitherto hypothetical neurophysin precursors. Incubation of neurohypophyses did not yield any signs of both conversion of neurophysin II into neurophysin III, and formation of further neurophysin derivatives.

Animals↗
PubMed1980

[Roentgenologic determination of maturity in low birthweight infants].

121 infants with low birthweight and a well known gestational age were divided into four groups: preterm infants, small for gestational age (SGA) infants, appropriate for gestational age (AGA) infants and infants with Clifford syndrome. With the 100 mm spot film technique X-rays of the right knee and ancle of the infants were taken and the size of the epiphyseal centers of the distal femur, the proximal tibia, the talus and the calcaneus was measured. The mean organ dose of the leg was only 2 mrad. All epiphyseal centers examined showed an increase from the 33rd to the 42nd week of gestation, which is in good agreement to previous studies. There was no evidence of a statistical difference of epiphyseal size between the four examined groups of neonates of low birthweight. Thus, in the present material with very close mean birthweights of the four groups, we were unable to distinguish preterm born infants from SGA infants with this method alone. This result suggests, that bone age is a more resistant criteria to fetal malnutrition than mass growth.

Age Determination by Skeleton↗
PubMed1980

[Maturity of lungs and bones at delivery. Comparison between surface tension measurement of the amniotic fluid and determination of size of infant knee-joint nuclei (author's transl)].

In 47 deliveries of term infants lung maturity studies (surface tension measurements in the Wilhelmy balance) were performed in the amniotic fluid collected at amniotomy. During the first three days post partum the bone age was assessed by radiological measurements of the epiphyseal centers. There was no correlation between the degree of lung- and scelettal maturity. These unexpected findings can be explained by 1) the biological variability in the degree of maturation of both organ systems 2) the false negative rate of both methods 3) the interesting fact, that those cases with spontaneous onset of contractions presented with a higher degree of lung maturity than those in whom labor was induced by amniotomy despite the fact that their pregnancies were of shorter duration. From the results of this study a certain link between the complete maturation of the lung and the spontaneous onset of uterine contractions might be assumed. With the concommitant use of both methods the false negative rate dropped to 1.2%. Consequently a radiological estimation of fetal bone age should be performed in case lung maturity studies are unequivocal.

Amniotic Fluid↗
PubMed1979

[Antenatal assessment of fetal maturity--a comparison of ultrasound-cephalometry and radiology (author's transl)].

334 ultrasound-cephalometries and 231 X-ray fetographies were performed for antenatal assessment of fetal maturity as well as for exact estimation of gestational age in women with unknown date of donfinement. The accurance of the predictions was compared. Ultrasound-cephalometry gave best results when performed until the 20th week of gestation. A correct prediction was obtained in 80.4% of cases. After the 20th week of gestation, the accuracy of prediction decreased. Radiology on the contrary gave optimal results at the end of pregnancy. A correct prediction of the date of confinement was obtained in 73.8% of cases, when the X-ray fetography was performed between the 37th and 40th week of gestation. At the end of gestation radiography should be performed, if there is a discrepancy between ultrasound and clinical estimation or if ultrasound-cephalometry was not carried out in early pregnancy--especially if induction of labour is necessary.

Cephalometry↗
PubMed1979

[Mammography of non-palpable lesions (spot localisation) (author's transl)].

Modern methods of mammary investigation currently enable the detection of tiny-tumours which are not clinically palpable and referral of these patients to surgery at an early stage. This poses a challenge to the surgeon, who cannot rely on palpation as a guide to accurate extirpation of the tumour, but has to rely wholly on the radiological report. A method was, thus, worked out in this department to provide accurate evaluation of the position of the suspect area of the breast to facilitate operative measures and, furthermore, act as safety measure between the time of tumor biopsy and receipt of the histological report. Preparation radiography proves that the suspect area on mammography is identical with removed specimen. The advantages of this procedure are obvious. The surgeon can rely fully on the radiodiagnostic findings and enlist the radiologist as essential member of the therapeutic team. As a result the operative procedure can be finely gauged by the surgeon and the tumour removed with maximum sparing of healthy breast tissue. This procedure has produced excellent results in 35 patients and can be recommended for application to patients with tiny tumours.

Aged↗
PubMed1979

Subcellular localization of the enzyme that forms mannosyl retinyl phosphate from guanosine diphosphate [14C]mannose and retinyl phosphate.

The subcellular distribution of the enzyme catalysing the conversion of retinyl phosphate and GDP-[14C]mannose into [14C]mannosyl retinyl phosphate was determined by using subcellular fractions of rat liver. Purity of fractions, as determined by marker enzymes, was 80% or better. The amount of mannosyl retinyl phosphate formed (pmol/min per mg of protein) for each fraction was: rough endoplasmic reticulum 0.48 +/- 0.09 (mean +/- S.D.); smooth membranes (consisting of 60% smooth endoplasmic reticulum and 40% Golgi apparatus), 0.18 +/- 0.03; Golgi apparatus, 0.13 +/- 0.03; and plasma membrane 0.02.

Animals↗
PubMed1979

An oxygen-binding flavohemoprotein from Alcaligenes eutrophus.

A procedure is described for the purification of a soluble flavohemoprotein from the hydrogen bacterium Alcaligenes eutrophus. The isolated protein exists as a monomer with a molecular weight of approx. 43,000. The molecule contains two prosthetic groups, 1 mol each of noncovalently bound FAD and protoheme per monomer. The absorption spectra of the protein in its ferric, ferrous-deoxy and ferrous-carboxy forms are similar to those of hemoglobins, with the exception of the flavin contribution (absorption maxima--ferric form: 395, 456, 483, 645 nm; ferrous-deoxy form: 436, 560 nm; ferrour-CO form: 423, 539, 569 nm). The flavohemoprotein when reduced by NADH in aerobic solution is capable of binding oxygen reversibly. The stable oxygenated complex exhibits absorption maxima at 414, 541, and 576 nm. The protein catalyzes the reduction of various dyes and cytochrome c by NADH.

Alcaligenes↗
PubMed1979

[The effect of hexestrol on the breast in climacteric women (author's transl)].

In 176 women hexestrol was substituted during 12 month or longer after ovarectomy and hysterectomy. Changes of the breast were watched by mammography and plate-thermography during hexestrol treatment. Also blood cagulation was examined. No differencies were found between these women and 179 women of a control group. In the authors opinion the substitution of hexestrol is justified further on in climacteric periods.

Adult↗
PubMed1979

alpha 2-Macroglobulin in vitamin A-deficient children.

Serum samples were obtained from 43 children 14 years old or younger in Malaysia and Guatemala. The levels of the serum glycoprotein alpha 2-macroglobulin (alpha 2-M) were assayed by two methods: the trypsin-binding assay of Ganrot (Clin. Chim. Acta 14:493, 1960) and a radial immunodiffusion assay against alpha 2-M antiserum. The two methods gave the same results. When serum alpha 2-M levels were plotted against serum vitamin A concentrations, they were significantly correlated (r = 0.505, P less than 0.001); children with serum vitamin A levels greater than 40 micrograms/100 ml had alpha 2-M levels of 3.71 +/- 0.79 mg/ml (mean +/- SD, n = 13), while those with level less than 40 micrograms/100 ml had alpha 2-M levels of 2.78 +/- 0.51 mg/ml (n = 30); the difference was significant (P less than 0.001). Normal, apparently healthy children had alpha 2-M levels of 3.90 +/- 0.39 mg/ml. Most of the children sampled suffered from a variety of infections; of these, measles appeared to counteract the effect of vitamin A deficiency by elevating alpha 2-M levels. Vitamin A-deficient children with measles had alpha 2-M levels not significantly lower than those of normal children. The difference between deficient and normal values of alpha 2-M was still significant (P less than 0.05) when expressed per milligram of serum protein, showing that the effect was not caused by lowered serum protein concentrations associated with protein-calorie malnutrition, from which most of the deficiency children suffered.

Adolescent↗
PubMed1979

The response of the acute-phase plasma protein alpha2-macroglobulin to vitamin A deficiency in the rat.

Alpha2-macroglobulin (alpha2-M) was determined in the sera of vitamin A-deficient and pair-fed control rats. Alpha2-macroglobulin levels were assayed by radial immunodiffusion using a purified standard sample from sera from turpentine-stressed rats. There was no significant increase in the serum level of alpha2-M in vitamin A-deficient rats relative to pair-fed controls, indicating that there was no acute response to the stress of the deficiency. When turpentine was injected to elicit an acute response, the serum level of alpha2-M rose equally (by almost 100-fold) in both deficient and normal rats. It was concluded that the response to vitamin A deficiency of serum glycoprotein synthesis shows some specificity in that the synthesis of alpha2-M in response to stress was not affected by vitamin A, whereas we previously found that levels of alpha1-M, which is very similar to alpha2-M, decline with vitamin A deficiency.

Animals↗