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Biomedical subjects

A Kahn

Publications and source records attributed to A Kahn.

At least 433 records · Page 24Linked to original sources
PubMed1984

Localization of a chemotactic domain in human thrombin.

The cyanogen bromide fragment CB67-129 of human prethrombin 1, corresponding to residues 54-116 of the thrombin B chain, is a potent chemotaxin for human peripheral blood monocytes and the murine macrophage like cell line, J774. Both of these cell types have been shown to respond chemotactically to alpha-thrombin and iPr2P-alpha-thrombin. Effective concentrations for stimulating directed cell movement with the fragment vary from 10(-11) to 10(-7) M. Moreover, CB67-129 and its parent protein compete for the same chemotactic receptor site. Fragment CB67-129, representing residues 54-116 of the human thrombin B chain sequence, contains a nine-residue insertion ("loop B") that is absent in homologous sequences derived from the closely related proteases chymotrypsin and trypsin. Unlike iPr2P-alpha-thrombin, iPr2P derivatives of these latter enzymes possess little or no chemotactic activity, suggesting a relationship between the insertion sequence and thrombin chemotactic activity. The loop B sequence is unique insofar as it contains all of the carbohydrate moieties known to reside in alpha-thrombin. However, chemotactic activity is only minimally reduced subsequent to hydrolysis by both neuraminidase and beta-galactosidase, indicating that receptor recognition and stimulated cell movement are mainly a function of structure of the cyanogen bromide derived fragment rather than of asparagine-linked carbohydrates.

Amino Acid Sequence↗
PubMed1984

A critical comparison of the history of sudden-death infants and infants hospitalised for near-miss for SIDS.

To determine whether significant historical differences distinguish the near-miss for Sudden Infant Death from the infants who died of SIDS, we analysed the histories and clinical data from two groups of infants seen in our University Hospital and from collaborative research group. The data were obtained with the use of a standardised questionnaire and consultation of all available medical data. Sixty-five infants were identified as near-miss for SIDS after they had suffered a severe cardiorespiratory incident during sleep for which no cause could be found despite a complete medical examination. After an autopsy had failed to reveal a cause for the unexpected death 95 cases of SIDS were retained in the study. A series of 353 variables were collected from the parents, the gynaecologists, neonatologists and attending physicians. After statistical analysis, only 15 of the 353 items studied significantly differentiated between the two groups. A step-wise discriminant analysis performed on these items led to the identification of six independent variables: the time of the incident; the circumstances leading to the observation of the child; the child's sleep position; previous minor intestinal problems; the size of the family and the mother's coffee consumption. Most variables indicate that the near-miss infants were discovered and rescued earlier than the infants who died. No other historical information appeared significantly to differentiate between the two groups of infants. These data need confirmation from a prospective epidemiological survey.

Family Characteristics↗
PubMed1984

DNA analysis in patients with hereditary fructose intolerance.

Restriction fragments of the aldolase B gene were studied in 11 patients with hereditary fructose intolerance and compared with the normal pattern. No major deletion of the gene was observed. One patient was found to be a compound heterozygote since one allele with normal restriction sites was inherited from the mother and the other with an abnormal Bam HI site was inherited from the father. The anomaly of the Bam HI fragment observed in this family was not found in 62 normal controls from the same origin as the patient.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1984

Reliability of clinical assessment of blunted affect.

The affect of 20 chronic schizophrenic in-patients was assessed by two psychiatrists using two rating scales. The interview recordings were reviewed three times--firstly with the auditory information only (the "audio review"), secondly with the visual information only (the "visual review") and thirdly with both (the "audio-visual review"). The "blunted affect score" correlated strongly with the total score of the verbal items of scales, but did not when a single mode of information was given. Since the absolute values of the "blunted affect score" were lower in the "visual review" than in the live interview and in the "audio-visual review", it was speculated that speech tended to bias the assessment of affect.

Adult↗
PubMed1984

Primary pulmonary amyloidosis.

A 51-year-old man with amyloidosis of the lungs, skin and testes, is described. For 7 years, there was an unusually slow progression of the disease and - compared to the literature - an uncommonly long survival.

Amyloidosis↗
PubMed1984

The genes coding for A alpha-, B beta-, and gamma-chains of fibrinogen map to 4q2.

We used cloned cDNA probes for the A alpha-, B beta-, and gamma-chains of human fibrinogen and Southern blotting techniques to analyze DNA from a series of rodent X human somatic cell hybrids for the presence of specific fibrinogen-related sequences. Our results provide evidence for the assignment of the three genes for fibrinogen to chromosome 4. Moreover, by direct gene-dosage determination in two patients with chromosome 4 unbalanced rearrangements, we refined the regional chromosomal assignment to 4q2, thus suggesting that these three genes whose expression is coordinately regulated are closely linked.

Animals↗
PubMed1984

Thyroid disorders.

Explore the source record for details and available documents.

Diagnosis, Differential↗
PubMed1984

Isozyme pattern in serially xenotransplanted childhood tumors.

Growth rate, histological course, and polymorphic enzyme pattern (glucose 6-phosphate dehydrogenase, glucose phosphate isomerase, and phosphofructokinase) were studied in eight childhood tumors xenotransplanted serially to nude mice. The growth rate of these tumors (three nephroblastomas, one hypercalcemic renal tumor, three rhabdomyosarcomas, and one malignant histiocytosis) appeared stable for any one particular tumor line. The time interval between two grafts varied from 1 to 3 weeks to 1 to 2 months in correlation with the clinical course of each malignant process. Histological changes were mostly in relation with a progressive dedifferentiation of the grafts. Immunoneutralization of glucose-6-phosphate dehydrogenase and glucose phosphate isomerase made possible the quantification of the stroma reaction in the grafts. A series of ten passages showed the amount of stroma to be constant for a given tumor type but variable from one tumor type to another, except for the malignant histiocytosis which showed an increase in stroma constituent after the sixth passage. One nephroblastoma tumor line showed, during the third passage, a sudden acceleration in the growth rate and complete transformation of the histological and isozymic patterns, which were interpreted as being the result of a murine lymphoma. The fibroblastic form of phosphofructokinase increased in every tumor line, whatever the tumor type. This change may be linked to a progressive dedifferentiation during the passage.

Animals↗
PubMed1984

The structural gene for transferrin (TF) maps to 3q21----3qter.

A cloned human cDNA for transferrin (TF) was used as hybridization probe in analysing a series of rodent x human somatic cell hybrids for the presence of human TF sequences. The assignment to chromosome 3 was further refined to region 3q21----3qter using hybrids that carried a translocated chromosome 3 and fibroblasts from a patient trisomic for this region. The gene for TF therefore maps to the same region as the gene for transferrin receptor (TFR) thereby defining an iron transport region on 3q2 to which the transferrin-related tumor associated antigen p97 may also belong. It follows that the genes for pseudocholinesterase (CHE1), ceruleoplasmin (CP) and alpha-2HS-glycoprotein (A2HS) which belong to the, as yet unassigned, linkage group of TF, now also map to chromosome 3 in man.

Animals↗
PubMed1984

Obstructive sleep apnea syndrome in childhood.

The review of 31 records of obstructive sleep apnea syndrome in childhood allows the authors to report some characteristics of the population and the clinical picture. They explain the diagnostic plan, detailing the need of combined ENT and pediatrician evaluations and the importance of the polygraphic sleep recording. They relate their therapeutical results after adenotonsillectomy in cases with lymphoid enlargement, after section of velopharyngeal flap in plasties for velopalatal incompetence and discuss their attitude in cases of other origins. They finally give the results of complete biological investigations performed in hope to find an univocal pathway to the observed massive lymphoid hyperplasia.

Adenoidectomy↗