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Biomedical subjects

M Roth

Publications and source records attributed to M Roth.

At least 307 records · Page 17Linked to original sources
PubMed1986

CAMDEX. A standardised instrument for the diagnosis of mental disorder in the elderly with special reference to the early detection of dementia.

A new interview schedule for the diagnosis and measurement of dementia in the elderly is described. The schedule named the Cambridge Mental Disorders of the Elderly Examination (CAMDEX), consists of three main sections: A structured clinical interview with the patient to obtain systematic information about the present state, past history and family history; a range of objective cognitive tests which constitute a mini-neuropsychological battery; a structured interview with a relative or other informant to obtain independent information about the respondent's present state, past history and family history. The CAMDEX is acceptable to patients, has a high inter-rater reliability and the cognitive section has been shown to have high sensitivity and specificity.

Aged↗
PubMed1986

Reciprocity of the neural growth in the Arnold-Chiari malformation.

It has been suggested (1) that nerves grow as plants grow. Extensive development of one nerve tends to retard its neighbours, lack of development tends to excite them to more active growth. This is a widespread neurobiologic phenomenon which may be traced up also in the pathomechanism of the Arnold-Chiari malformation: Impairment of the neural growth at the level of a lumbosacral meningomyelocele results in overgrowth of the cranio-cervical nerves associated with shortening of the cervical cord segments. A similar reciprocity, normal and pathologic, seems to work also between the nerve roots of the cauda equina and the lumbosacral segments of the spinal cord.

Arnold-Chiari Malformation↗
PubMed1986

[Experiences with sonographically guided percutaneous nephrostomy].

It is reported on 65 sonographically directed percutaneous nephrostomies in 47 patients. In the description of the technique it is particularly referred to the advantages of a rigid bouginage system, an exact local anaesthesia and a transparenchymal access to the pyelon. Complications due to the intervention occurred in 4 patients. 10 postrenal anurias were cured and 9 out of 10 patients with a urosepsis due to urinary obstruction were successfully treated. The percutaneous nephrostomy is recommended as a slightly traumatising access to the cavity system of the kidneys, which is to be used also in patients who cannot tolerate an open operation on account of a reduced general condition.

Adolescent↗
PubMed1986

Colorimetric determination of carboxypeptidase A activity in serum.

This simple, reproducible colorimetric method for determining the activity of carboxypeptidase A (EC 3.4.17.1) is based on measuring the absorbance at 505 nm of a quinoneimine dye produced from the action of this enzyme on the new substrate p-hydroxybenzoyl-glycyl-L-phenylalanine. The enzyme acts on the substrate to produce p-hydroxybenzoyl-glycine and L-phenylalanine. The former is then hydrolyzed by hippuricase (EC 3.5.1.14) to produce p-hydroxybenzoic acid and glycine. Finally, oxidative coupling of p-hydroxybenzoic acid with 4-aminoantipyrine by sodium periodate forms a quinoneimine dye. The Km for the reaction with this substrate is 3.6 mmol/L; the optimum pH is 7.8. Our within-run and between-run CVs are 4.3% and 6.6%, respectively. The activity of carboxypeptidase A in serum correlates well with that of lipase (r = 0.96) and immunoreactive elastase-1 (r = 0.76).

Amidohydrolases↗
PubMed1986

Extended use of computed tomography in the management of complex aortic problems: a learning experience.

Eighty-nine patients with clinical problems arising from the thoracic or abdominal aorta had computed tomography (CT) scans with contrast enhancement in addition to standard aortograms. Forty-four patients had aneurysms, 22 had aortic graft complications, and 23 had aortoiliac occlusion. CT scanning provided diagnostic information not apparent by conventional angiography in 39 patients (43.8%). This additional information did not significantly alter the operative management in 13 patients (14.6%). The helpful information provided by CT in these patients included demonstration of gallstones, renal cysts, anomalous venous structures, horseshoe kidney, and femoral anastomotic aneurysms. However, in 26 of 89 patients (29%), the additional data obtained by CT significantly changed the timing or approach to operative management. Management was altered in 12 of 44 patients (28%) with aneurysms, 7 of 22 patients (32%) with aortic graft complications, and 7 of 23 patients (30%) with aortoiliac occlusive disease or suspected distal thromboembolism. Specific information provided by CT included contained aortic aneurysm rupture, aortic dissection, laminated intraluminal thrombus or pseudointima, extent of perigraft infection, aortic atherosclerosis, anastomotic false aneurysm, and thrombus as a source of distal embolization. Thus, CT had a significant impact on operative management. It serves as a valuable adjunct to aortography in patients with complex aortic problems.

Aged↗
PubMed1985

Modification of immunogenic tumor growth by adrenalectomy in a syngeneic murine system.

The immunosuppressive action of adrenal glucocorticosteroids is well-known, and depressed cell-mediated immunity and adrenal cortical hyperplasia have been described in tumor-bearing animals. This study was designed to evaluate the effect of removing the source of lympholytic steroids by adrenalectomy upon tumor growth rate, thymus weight, and thymocyte incorporation of iodine 125 (125I) deoxyuridine into DNA. Newly derived methylcholanthrene-induced immunogenic fibrosarcomas were used in male syngeneic mice. Log dosages of 10(4), 10(5), and 10(6) viable tumor cells as single cell suspension were injected subcutaneously into the popliteal space of adrenalectomized and control mice. Tumor size was followed serially with caliper measurements, and the animals were killed 4 weeks after inoculation. Adrenalectomized mice inoculated with 10(4) cells had smaller tumors (P less than 0.02), heavier thymi (P less than 0.01), and more thymic DNA synthesis (P less than 0.05) than their tumor-bearing controls. No differences were seen between populations receiving 10(5) or 10(6) tumor cell inoculations. A second experiment was carried out in which intact controls, adrenalectomized animals, and sham adrenalectomy animals were inoculated with 10(4) tumor cells and killed 28 days later. Tumor growth rate and volume were significantly decreased for the adrenalectomized mice, which had higher thymus weights and DNA synthesis. These findings suggest that pretreatment adrenalectomy slows the growth of antigenic tumor cells and prevents thymic involution after tumor growth in a syngeneic murine system.

Adrenalectomy↗
PubMed1985

Influence of inorganic phosphate on the lipid synthesis of a phosphate-deregulated mutant of Streptomyces noursei.

Phosphate-dependent changes of the mycelial lipid composition were studied in the streptothricin-producing parental strain Streptomyces noursei JA 3890 b/2 and its mutant RG 2. In contrast to its ancestor, the mutant was capable of producing the antibiotic nourseothricin even when large quantities of inorganic phosphate were present in the medium. The apparent insensitivity of the secondary metabolism to phosphate inhibition corresponds to a decreased level of phospholipids in the presence of excessive inorganic phosphate and, during phosphate limitation, to a much higher production of the alkaline phosphatases. A model is discussed which proposed the control by a common genetic element of both the phospholipid and antibiotic production.

Alkaline Phosphatase↗
PubMed1985

[Familial cancer. Initial results of an inquiry into its occurrence in Basel].

The initial results of a systematic study conducted in Basel on the existence of relatives with cancer in the families of more than 600 tumour patients indicate that neoplasm of all organs have forms in whose etiology genetic predisposition is an important factor. This is illustrated by the examples of mammary carcinoma, colorectal carcinoma, gastric carcinoma and lymphoproliferative diseases. Research into genetic predisposition to cancer is of practical value in order to protect persons at risk from the serious consequences of malignant tumors, and also of scientific interest because the characterisation of certain tumours can provide a fundamental insight into the pathogenesis of these diseases.

Breast Neoplasms↗
PubMed1985

DNA intermediates and telomere addition during genome reorganization in Euplotes crassus.

Three gene-sized molecules cloned intact from macronuclear DNA served as hybridization probes to study excision of these molecules from chromosomes and their processing during macronuclear development in the hypotrich Euplotes crassus. These molecules occur in integrated forms within polytene chromosomal DNA during macronuclear developmental. After transection of the polytene chromosomes, the three molecules occur in intermediate forms. One of the three molecules first appeared in a large intermediate that was subsequently replaced by a second intermediate, approximately 140 bp larger than the final molecule. The other two macronuclear molecules were detected only in intermediates approximately 140 bp larger than the mature form. These penultimate intermediates are larger by virtue of oversized telomeres, which are pared to yield the mature gene-sized molecules.

Animals↗
PubMed1985

Expression of enzymatically active reverse transcriptase in Escherichia coli.

Reverse transcriptase of murine retroviruses is a monomeric protein of approximately 80,000 daltons, which is encoded by the central portion of the viral pol gene. To prepare large quantities of the enzyme, we have constructed gene fusions between the trpE gene and portions of the pol gene of Moloney murine leukemia virus. The inserted pol gene sequences include the entire coding region for the mature enzyme and various amounts of additional coding sequences. Many of these constructs express high levels of reverse transcriptase activity even though the NH2 and COOH termini of the protein product only approximate the correct termini of the authentic protein.

DNA, Recombinant↗
PubMed1985

Subunit structure of paired helical filaments in Alzheimer's disease.

The neurofibrillary tangles that occur in the brain in cases of senile dementia of the Alzheimer type contain a distinctive type of filament, the paired helical filament (PHF). We have developed a method for isolating the tangles postmortem in sufficient yield for structural study of PHFs by electron microscopy of negatively stained and shadowed preparations. This material shows the characteristic helical structure seen in sectioned embedded material. In addition, two striking fragmentation patterns are observed. (a) Some filaments show sharp transverse breaks at apparently random positions along the filament. (b) In a few PHFs one strand is missing for a variable length, whereas the other appears to maintain its structural integrity. The shadowed specimens show the PHF to be wound in a left-handed manner. These observations indicate that the PHF consists of subunits of very limited axial extent arranged along two left-handed helical strands. The visualization of the substructure within the PHFs is rather variable and a model building approach has therefore been adopted, which has allowed the main features seen in the images to be interpreted. The subunit appears to have at least two domains in a radial direction and an axial extent of less than 5 nm. The whole structure can best be described as a twisted ribbon and indeed alkali treatment does untwist PHFs to give flat ribbons. The nature of the proposed model makes it most unlikely that the PHF is formed by a simple collapse of normal cytoskeletal elements, such as neurofilaments.

Aged↗
PubMed1985

Large scale synchronous mating and the study of macronuclear development in Euplotes crassus.

After conjugation in hypotrichous ciliates, a new macronucleus is produced from a copy of the micronucleus. This transformation involves large-scale reorganization of DNA, with conversion of the chromosomal micronuclear genome into short, gene-sized DNA molecules in the macronucleus. To study directly the changes that occur during this process, we have developed techniques for synchronous mating of large populations of the hypotrichous ciliate Euplotes crassus. Electron microscope studies show that the micronuclear chromosomes are polytenized during the first 20 h of macronuclear development. The polytene chromosomes lack the band-interband organization observed in other hypotrichs and in the Diptera. Polytenization is followed by transectioning of the chromosomes. We isolated DNA at various times of macronuclear development and found that the average molecular weight of the DNA decreases at the time of chromosome transectioning. In addition, we have shown that a small size group of macronuclear DNA molecules (450-550 base pairs) is excised from the chromosomal DNA approximately 10 h later in macronuclear development.

Animals↗