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Biomedical subjects

M Berger

Publications and source records attributed to M Berger.

At least 1,081 records · Page 60Linked to original sources
PubMed1975

Production of antibodies that bind biotin and inhibit biotin containing enzymes.

Methods were developed for the coupling of biotin to bovine serum albumin and bovine gamma-globulin using a water-soluble carbodimide. The use of [14-C]biotin as a tracer allowed quantitation of the incorporation of biotin into the conjugates: 2.55 mol of biotin was incorporated per mol of gamma-globulin and 7-9 mol of biotin was incorporated per mol of serum albumin in different preparations. These conjugates were highly immunogenic in the rabbit and anti-bodies reactive with the biotinyl group itself could be detected by their ability to precipitate the heterologous biotinated carrier but not the unmodified heterologous carrier. There antisera rapidly inactivated transcarboxylase and pyruvate carboxylase and this inactivation could be blocked by pretreatment of the antisera with biotin or biocytin. Using enzyme inhibition to detect free antibody, the binding constant for biotin was found to be 5.0 x 10- minus 8 M and that for biocytin 3.5 x 10- minus 8 M.

Animals↗
PubMed1975

Purification of the subunits of transcarboxylase by affinity chromatography on avidin-sepharose.

Transcarboxylase consists of a central 12 SH subunits each of which is linked to the central subunit by two similar to 1.3 SE biotin carboxyl carrier proteins. The subunits from dissociated transcarboxylase have been difficult to isolate because conditions which stabilize them also promote their reassociation to the intact enzyme. In this paper, we describe the use of avidin-Sepharose to adsorb the enzyme from crude extracts or partially purified transcarboxylase of propionibacteria. After removing impurities by washing the column with phosphate buffer at pH 6.5, in which the transcarboxylase is stable, the enzyme is dissociated first by elution at pH 8 yielding a fraction containing mostly 12 SH subunit which can be rapidly stabilized against dissociation to 6 SH without the problem of reconstitution because the 1.3 SE and most of the 5 SE subunits are not eluted. The second elution is at pH 9 which yields the 5 SE subunit by dissociation from the 1.3 SE biotin subunit and the 1.3 SE subunit remains bound to the avidin. The 12 SH and 5 SE subunits are further purified by glycerol density gradient centrifugation or by chromatography on Bio-Gel. Very active enzyme can be reconstituted from these subunits upon the addition of the 1.3 SE subunit.

Avidin↗
PubMed1975

Urinary lactic dehydrogenase isoenzyme 5 in the differential diagnosis of kidney and bladder infections.

Urinary lactic dehydrogenase (U-LDH) isoenzyme assays were performed on ch2) as well as normal controls (N = 24). Docuemntation of bladder and kidney infection was accomplished by means of the bladder washout test, culture of ureteric urine (in patients with urinary diversion), kidney function studies including the maximal urine concentration test, clinical symptomatology and radiologic appearance of the urinary tract. Total U-LDH in normal children (10.8 +/- 1 mU/ml) was lower than in patients with bladder (27.0 +/- 3.9 mU/ml) or kidney (226 +/- 67.3 mU/ml) infections (P less than 0.005). In normal children isoenzymes 1 and 2 predominated (LDH-1 migrates fastest to anode -- fast zone pattern). In patients with bladder infections, the isoenzyme patterns varied but the concentration of isoenzyme 5 (3.1 +/- 0.8 mU/ml) was lower (P less than 0.005) than in patients with kidney infections (120 +/- 39 mU/ml). In the latter, isoenzymes 4 and 5 predominated (slow zone pattern). Since overlap between kidney and bladder infections regarding isoenzyme 5 concentrations (at 3 SD) occurred in only one individual (patient 37), a correct differential diagnosis using U-LDH-5 alone would have been possible in 94% of the children with pyelonephritis or 97% of the total patient population (kidney + bladder).

Adolescent↗
PubMed1975

Glucose metabolism in perfused skeletal muscle. Interaction of insulin and exercise on glucose uptake.

1. The interaction of insulin and isometric exercise on glucose uptake by skeletal muscle was studied in the isolated perfused rat hindquarter. 2. Insulin, 10 m-i.u./ml, added to the perfusate, increased glucose uptake more than 10-fold, from 0.3-0.5 to 5.2-5.4 mumol/min per 30g of muscle in hindquarters of fed and 48h-starved rats respectively. In contrast, it did not stimulate glucose uptake in hindquarters from rats in diabetic ketoacidosis. 3. In the absence of added insulin, isometric exercise, induced by sciatic-nerve stimulation, increased glucose uptake to 4 and 3.4 mumol/min per 30g of muscle in fed and starved rats respectively. It had a similar effect in rats with moderately severe diabetes, but it did not increase glucose uptake in rats with diabetic ketoacidosis or in hindquarters of fed rats that had been "washed out" with an insulin-free perfusate. Insulin, at concentrations which did not stimulate glucose uptake in resting muscle, restored the stimulatory effect of exercise in these situations. 4. The stimulation of glucose uptake by exercise was independent of blood flow and the degree of tissue hypoxia; also it could not be reproduced by perfusing resting muscle with a medium previously used in an exercise experiment. 5. At rest glucose was not detectable in muscle cell water of fed and starved rats even when perfused with insulin. In the presence of insulin, a small accumulation of glucose, 0.25 mM, was noted in the muscle of ketoacidotic diabetic rats, suggesting inhibition of glucose phosphorylation, as well as of transport. 6. During exercise, the calculated intracellular concentration of glucose in the contracting muscle increased to 1.1-1.6mM in the fed, starved and moderately diabetic groups. Insulin significantly increased the already high rates of glucose uptake by the hindquarters of these animals but it did not alter the elevated intracellular concentration of glucose. 7. In severely diabetic rats, exercise did not cause glucose to accumulate in the cell in the absence of insulin. In the presence of insulin, it increased glucose uptake to 6.1 mumol/min per 30g of muscle and intracellular glucose to 0.72 mM. 8. The data indicate that the stimulatory effect of exercise on glucose uptake requires the presence of insulin. They suggest that in the absence of insulin, glucose uptake is not enhanced by exercise owing to inhibition of glucose transport into the cell.

Animals↗
PubMed1975

Serum triiodothyronine 7-15 years after fractionated low dose radioiodine therapy of thyrotoxicosis.

In 189 of 334 patients, who had been treated with fractionated doses of radioiodine for Graves' disease 7-15 years ago, the serum concentrations of triiodothyronine have been estimated in additition to the following parameters: Protein bound 127-iodine (PB-127-I), free thyroxine index, cholesterol- and TSH-level in serum, tendon reflex time and clinical index according to Billewitz et al. (1969). In forty-one of the 189 sera the free T4 (AFT4) and free T3 (AFT3) concentrations were measured as well. The following hormonal and clinical patterns were observed: (1) Euthyroidism, with all parameters within the normal range in 148 patients (equals 78-4%). (2) Hypothyroidism with low serum T3, PBI, AFT4, AFT3 and elevated TSH six subjects (equals 3-2%). (3) Persistent hyperthyroidism with increased thyroid hormone concentrations and low TSH in seven cases (equals 3-7%). (4) In twenty-eight clinically euthyroid patients (equals 14-8%) TSH was elevated with normal PBI and AFT4. Twenty of these subjects had a low normal T3 and in nine the T3 was clearly in the hypothyroid range (40 plus or minus 12 mug/dl). (5) The constellation of normal T3, low T4 and elevated TSH, which has been frequently found after radioiodine therapy, has been seen in only moderate form in ten cases.

Adult↗
PubMed1975

Attainment and adjustment in two geographical areas. II--The prevalence of specific reading retardation.

Specific reading retardation was found to occur in a minimum of 9-9 per cent of ten-year-old 'indigenous' children in one inner London borough. This rate was nearly three times that (3-9 per cent) in Isle of Wight children. There was a comparably higher rate of general reading backwardness in London (19-0 per cent vs 8-3 per cent). Since the same epidemiological methods were followed in the two areas, and since the reading-retarded children had similar psychological characteristics in both cases, it is concluded that there is a real difference between London and the Isle of Wight in the prevalence of reading retardation and of reading backwardness.

Achievement↗
PubMed1975

Attainment and adjustment in two geographical areas: III--Some factors accounting for area differences.

It was found that emotional disorders, conduct disorders and specific reading retardation were all twice as common in ten-year-old children attending schools in an inner London borough as in children of the same age on the Isle of Wight. The correlates of these disorders in the two areas were investigated in order to explore possible reasons for these differences in prevalence. It was possible to identify four sets of variables (family discord, parental deviance, social disadvantage and certain school characteristics) which were associated with child disorder and deviance within both the two areas. As in almost all cases these same adverse factors were more commonly found in London, it may be concluded that the high rates of psychiatric disorder and specific reading retardation in London ten-year-olds are due in part to the fact that a relatively high proportion of London families experience marital discord and disruption, that many of the parents show mental disorder and antisocial behaviour, that families often live in poor social circumstances, and that the schools are more often characterized by a high rate of turnover in staff and pupils. The evidence suggests that these problems stemmed from living in an inner London borough, but further research is required to identify what it is about life in a metropolitan area that predisposes to the development of disorder and deviance.

Affective Symptoms↗
PubMed1975

Intracavitary metastasis to the left ventricle: an angiocardiographic diagnosis.

A patient with an intracavitary metastasis to the outflow tract of the left ventricle diagnosed prior to the primary tumours is presented. It is unique in location, type and diagnosis. Metastatic disease of the heart is far more common than primary cardiac tumours and usually is diagnosed late in the course of the disease or at autopsy. Angiocardiography is the best method of diagnosing tumours of the heart and should be performed whenever such a diagnosis is considered.

Angiocardiography↗
PubMed1975

Thyroid function and triiodothyronine and thyroxine kinetics in rabbits immunized with thyroid hormones.

Neck-uptake studies, thyroid scintiscans and triiodothyronine (T4)-kinetic studies were performed in normal rabbits and in animals producing antibodies against thyroid hormones. In immunized animals the radioiodide uptake and turnover were increased 3-fold and 6-17-fold, respectively. The thyroid glands were found to be enlarged scintigraphically and showed a denser tracer distribution pattern. T3 and T4 kinetic data were obtained from 5 rabbits immunized with T3 (ABT3), 4 immunized with T4 (ABT4) and from 5 controls. In T3 immunized animals total T3 in the serum rose from 86 to 59 000 ng/100 ml, in T4 immunized rabbits total T4 increased from 2.5 to 53.8 mug/100 ml. The fundamental principles of regulation were similar in both T3 and T4 immunized rabbits: There were enormous decreases in the total distribution spaces (TDS) as well as in the fractional turnover rates (k), resulting in markedly decreased metabolic clearance rates (MCR). The fall in T3-MCR was directly proportional to the T3 binding activity of the sera. However, striking differences between the respective alterations of T3 and T4 kinetic data were obtained in the immunized animals: T3-MCR fell about 70-fold in ABT3, whereas T4-MCR was diminished 15-fold in T4 immunized rabbits. In both groups of immunized animals T3-TDS decreased more than the T3 fractional turnover, whereas T4-TDS was less affected than k T4. The T3 production rates (PR) were increased 10-fold in ABT3 and 5-fold in ABT4, whereas the increases in T4-PR were of only moderate degree both in ABT3 and ABT4. Using presently available radiochemical methods in metabolic status of immunized rabbits could not be definitely assessed: "clinically" the animals were euthyroid. However, the dialyzable fraction in the serum of both T3 and T4 did not decrease proportionately to the enormous increase in total hormone concentration, so the free hormone concentrations were elevated over the normal. The results of the calculations of the cellular hormonal T3- and T4-clearance were more consistent with a euthyroid state: In ABT4 the cellular metabolism of both hormones was not different from the normal; in ABT3 a 1.7-fold increase in the cellular clearance of T3 was accompanied by a significant decrease of that in T4.

Animals↗
PubMed1975

[Radioimmunoassay of testosterone in late fetal and newborn rabbit plasma, gonads and adrenal glands].

A radioimmunoassay was used for measuring testosterone in the plasma, gonads and adrenals of 28, 29, 30 and 31-day-old rabbit fetuses of both sexes and newborns. A marked sex difference was shown in the concentrations of testosterone in plasma and in gonads whereas in adrenals the levels of testosterone were low in both sexes (34 to 147 pg/10 mg). In male fetuses, plasma testosterone levels increased from the 28th (133 +/- 20 pg/ml) to the 31st day (361 +/- 119 pg/ml) of intrauterine life, reaching then the values observed in the newborns (387 +/- 73 pg/ml). Plasma from males, on the other hand contained, at all stages studied, significantly more testosterone than plasma from female fetuses (21 +/- 6 to 41 +/- 11 pg/ml) and female newborns (42 +/- 6 pg/ml). In the same way, fetal testicular testosterone concentrations varying from 1 382 +/- 218 to 2 317 +/- 333 pg/10 mg were similar to those measured in the newborns (1 940 +/- 304 pg/10 mg) and significantly higher than fetal (13 to 34 pg/10 mg) or neonatal (44 pg/10 mg) ovarian concentrations. These results showed at evidence the endocrine activity of the fetal testis during this period.

Adrenal Glands↗