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Biomedical subjects

M Mandel

Publications and source records attributed to M Mandel.

At least 73 records · Page 4Linked to original sources
PubMed1992

Superior vena cava syndrome associated with lymphoma.

OBJECTIVE: To evaluate the workup and treatment of children with lymphoma and superior vena cava syndrome. DESIGN: A retrospective survey. SETTING: State hospital serving as a secondary and tertiary referral center for pediatric oncology and pediatric cardiac surgery. PARTICIPANTS: Eleven children aged 11 months to 12 years diagnosed as having lymphoma or T-cell acute lymphoblastic leukemia who presented with superior vena cava syndrome during an 11-year period. INTERVENTIONS: Lymph node biopsy (two patients), thoracenthesis (five patients), bone marrow aspiration (two patients), and thoracenthesis in addition to bone marrow aspiration (two patients). All aspirates were evaluated with immunohistochemical studies. Chemotherapy was the only management intervention. RESULTS: T-cell lymphoma or leukemia accounted for nine cases and Hodgkin's disease for two cases. Respiratory symptoms occurred in 10 patients, including tracheal compression in six patients (compression was life-threatening in one patient). Diagnosis of superior vena cava syndrome was achieved in eight patients using surface-marker analysis of aspirates. The syndrome disappeared within 2 to 10 days. Seven of nine children whose conditions were diagnosed more than 1 year before this writing were alive and free of disease after mean follow-up of 37 months. CONCLUSIONS: (1) A specific diagnosis can be achieved in most children with superior vena cava syndrome and lymphoma; (2) Thoracic computed tomographic scans are essential, identifying minute pleural effusions that can aid diagnosis; (3) Anesthetic hazard is related only to severe tracheal compression; (4) Chemotherapy achieves excellent symptomatic relief; and (5) Long-term survival, without disease, is achievable.

Child↗
PubMed1992

The management of pediatric brain tumors in a tertiary center.

Between January 1982 and January 1990, 120 newly diagnosed pediatric patients were treated at The Chaim Sheba Medical Center. Sixty three (52.5%) tumors arose in the posterior fossa and 57 (47.5%) appeared supratentorially. A wide variety of histologic subtypes was seen, each requiring tumor-specific treatment. The modern imaging techniques-CT and MRI-offered better planning of operation, treatment and follow up. All children with highly malignant tumors were treated with combination chemotherapy besides the 'conventional radiotherapy'. Since 1987 the "eight in one day" protocol has been used extensively pre- and post-irradiation. Five-year survival, varied significantly according to tumor type, location and stage. The average delay from presentation of symptoms to diagnosis was 6 months. A multidisciplinary approach has been used in the treatment, rehabilitation and follow-up of these children. In this study, the results of treatment are presented and the role of chemotherapy is discussed.

Adolescent↗
PubMed1992

The complementary deoxyribonucleic acid sequence of guinea pig endometrial prorelaxin.

The nucleotide sequence of the relaxin gene transcript in the endometrium of the late pregnant guinea pig has been determined. The strategy used was a combination of polymerase chain reaction (PCR) with primers designed from the mRNA sequence of porcine preprorelaxin, rapid amplification of cDNA ends-PCR, and blunt end cloning in M13 mp18. With heterologous primers, a 226-basepair (bp) segment of the guinea pig relaxin gene sequence was obtained and was used to design a guinea pig-specific primer for use with the rapid amplification of cDNA ends-PCR method. The latter allowed completion of the sequence of 336 bp, with a 96-bp overlap. The sequence obtained shows greater homology at both the nucleotide and amino acid levels with porcine and human relaxins H1 and H2 than with rat relaxin, supporting the thesis that the guinea pig is not a rodent. The transcription of the guinea pig endometrial relaxin gene during pregnancy was confirmed by Northern analysis of guinea pig endometrial tissues with a species-specific cDNA probe. The endometrial relaxin gene is transcribed during pregnancy, but not in lactation, consistent with the observed immunostaining for relaxin.

Amino Acid Sequence↗
PubMed1991

Thermal stability of turnip yellow mosaic virus RNA: effect of pH and multivalent cations on RNA deaggregation and degradation.

Light scattering studies of RNA isolated from turnip yellow mosaic virus (TYMV) revealed a molar mass of 1.9.10(6) g mol-1, which is close to the value of 2.0.10(6) g mol-1 published for intact genomic TYMV RNA (2M RNA). However, gel electrophoresis under denaturing conditions demonstrated that only 30-40% of this native RNA was 2M RNA. Sucrose gradient centrifugation revealed the occurrence of a series of smaller RNA size classes, the mass ratios of which were greatly influenced by the pH of the solution and the presence of EDTA. These results suggest that native TYMV RNA preparations originally contain a mixture of intact RNA particles and of aggregates of RNA fragments with the same molar mass of about 2.10(6) g mol-1, and that the size classes are intermediates in the deaggregation process of the degraded genomic TYMV RNA. The native RNA displayed pH-dependent deaggregation and degradation. The degradation process of 2M RNA followed (pseudo) first-order kinetics. Lower degradation rates were observed for RNA depleted of divalent cations and polyamines. For depleted 2M RNA an enthalpy of activation of about 100 kJ mol-1 and an almost zero entropy of activation was calculated. Similar values were also found for depleted E. coli ribosomal RNAs and depleted MS2 RNA, demonstrating that all RNAs are equally vulnerable to degradation. In the presence of multivalent cations the activation enthalpy for 2M TYMV RNA degradation increased to 150 kJ mol-1 and the entropy of activation to 150 J K-1 mol-1, indicative for a different degradation mechanism.

Cations, Divalent↗
PubMed1991

Lack of bcr rearrangement in juvenile chronic myeloid leukemia.

Juvenile chronic myeloid leukemia (JCML) is an unusual subtype of children's leukemia, characterized by unique clinical presentation. Recent studies revealed several biological features, distinguishing from those observed in adult type chronic myeloid leukemia (ACML). The majority of ACML cases are characterized by the presence of an hybrid bcr-abl rearranged gene. In an effort to elucidate the molecular basis of this unusual leukemia we looked for bcr rearrangement in six JCML cases. No bcr rearrangement was identified in any of the analyzed samples. Together with previous studies from JCML cases, JCML has a different mechanism of leukomogenesis from ACML.

Blotting, Southern↗
PubMed1991

Dynamic light scattering by kappa- and lambda-carrageenan solutions.

The intensity correlation functions of kappa- and lambda-carrageenan in various salt solutions and at different concentrations have been determined with the help of dynamic light scattering. From the first cumulant of these correlation functions the values of the translational diffusion coefficients D have been derived. They increase with macromolecular concentration. The extrapolated values to infinite dilution of the diffusion coefficients increase with increasing salt concentration as expected from the salt concentration dependence of the r.m.s. radii of gyration determined previously by static light scattering. The translational diffusion coefficient of lambda-carrageenan in 0.1 M NaCl is smaller than the corresponding value for the kappa species. This is consistent with the difference in contour length and linear charge density of the two samples used. No satisfactory interpretation for the concentration dependence of the diffusion coefficient seems to be possible at present. Although current theories for the macromolecular and salt concentration dependence of D, taking into account charge effects, seem to be applicable, they do not allow for a consistent interpretation of the data. No specific difference between the solution behaviour of kappa- and lambda-carrageenan has been detected.

Carrageenan↗
PubMed1991

Bone marrow cell populations mimicking common acute lymphoblastic leukemia in infants with stage IV-S neuroblastoma.

Immunophenotyping of bone marrow mononuclear cells of 2 infants with stage IV-S neuroblastoma revealed the presence of many lymphoblasts and immature lymphocytes. Immunophenotyping showed that a high percentage of bone marrow cells were positive for the HLA-DR, CD19, CD20 and CD10 phenotype, similar to common acute lymphoblastic leukemia cells. Within 6 months of follow-up, without any treatment, complete regression of the tumors was observed. The coexistence of these two unusual populations will be discussed.

Bone Marrow↗
PubMed1990

A hydrodynamic study with quasielastic light scattering and sedimentation of bacterial elongation factor EF-Tu.guanosine-5'-diphosphate complex under nonassociating conditions.

The hydrodynamics of the bacterial elongation factor EF-Tu have been studied in the presence of its ligand guanosine-5'-diphosphate (GDP) by sedimentation in the ultracentrifuge and quasielastic light scattering. Sedimentation studies have made it possible to establish experimental conditions under which only negligible aggregation of the protein occurs (neutral pH, concentration less than 3 mg/mL). Analysis of the light intensity autocorrelation functions under these conditions revealed two independent scattering species with diffusion coefficients of 0.71 X 10(-6) and 0.04 X 10(-6) cm2 s-1. The material with the lower diffusion coefficient, i.e., the aggregates, represented less than 1% of the total number of EF-Tu particles. The other 99% diffused as monomeric molecules with a molar mass corresponding to the value calculated from the known primary structure of the protein. The hydrodynamic parameters derived from the experimental data suggest that EF-Tu.GDP in solution is close to a spherical particle.

Escherichia coli↗
PubMed1990

Endogenous opioid effects on abdominal muscle activity during inspiratory loading.

In a previous study in unanesthetized goats, we demonstrated that continuous naloxone (NLX) administration during inspiratory flow-resistive loading (IRL) significantly increased tidal volume (VT) but not diaphragm electromyogram (EMGdi). End-expiratory gastric pressure did increase with NLX, implying that increased abdominal muscle activity may have accounted for the NLX effect. In the current study we directly tested the hypothesis that endogenous opioid elaboration depresses the abdominal muscle response to a continuous inspiratory flow-resistive load. In seven unanesthetized goats, VT, arterial blood gases, EMGdi, and EMG activity of external oblique (EMGeo), transversus abdominis (EMGta), and external intercostal (EMGei) muscles were monitored. IRL (50 cmH2O.l-1.s) was continued for 3 h, after which NLX (0.1 mg/kg) or saline was given. Our results showed that VT decreased from 323 +/- 32 (SE) ml at baseline to 260 +/- 16 ml 5 min after the load was imposed (P less than 0.05) and further decreased to 229 +/- 18 and 217 +/- 15 ml by 120 and 180 min, respectively (180 vs. 5 min, P less than 0.05). EMGdi increased from 62 +/- 5 to 83 +/- 4% max at 5 min (P less than 0.05) but was unchanged thereafter. In contrast, for this same time period EMGeo increased from 35 +/- 5 to 58 +/- 11% max but decreased from 67 +/- 11% max at 120 min to 37 +/- 5% max at 180 min (P less than 0.05). NLX administration resulted in significant increases in EMGeo (91% above 180-min value). In contrast, EMGdi increased minimally after NLX (15% above 180-min value).(ABSTRACT TRUNCATED AT 250 WORDS)

Abdomen↗
PubMed1990

[In vitro evaluation of antibacterial activity of the original oxime type of beta-lactam antibiotics with the 4-aminobenzensulfonamide group].

Four newly prepared beta-lactam antibiotics of the oxime type with a 4-aminobenzensulphonamidogroup, synthetized at the Research Institute for Pharmacy and Biochemistry, Prague, were subjected to an evaluation of antibacterial efficacy in vitro. The evaluation was carried out by determining the minimal inhibitory concentration (MIC) in 47 clinical strains and 6 standard strains (Staphylococcus aureus, Streptococcus pyogenes and facecalis, E. coli, Enterobacter and Proteus spec., Pseudomonas aeruginosa). The results were compared with the MIC of cefalexin, cefoxitin, cefazolin, cefsulodin, and ampicillin. The antibacterial effect of these agents was lower than that of the compared antibiotics. It was slightly better in the pseudomonadic strains, where the efficacy of cefusulodin was best and the other four antibiotics appeared to be worst.

Ampicillin↗
PubMed1990

[In vitro antibacterial activity of new oxime type of beta-lactam antibiotics].

The antibacterial efficacy of two novel beta-lactam antibiotics of the oxime type, VUFB 16265 and 16272, was evaluated by determining the minimal inhibitory concentration (MIC) in 47 clinical strains and 6 standard strains (Staphylococcus aureus, Streptococcus pyogenes and faecalis, E. coli, Enterobacter and Proteus spec., Pseudomonas aeruginosa), which were the most frequent causes of infectious complications. The results were compared with the MIC of cefalexin, cefoxitin, cefazolin, cefsulodin, and ampicillin. The antibacterial activity of both VUFB drugs was comparable with the efficacy of the antibiotics tested. Only in the strains of Pseudomonas aeruginosa the activity of all antibiotics under evaluation was low and only cefsulodin was effective.

Ampicillin↗
PubMed1989

Immunoglobulin heavy chain gene rearrangements in chronic lymphocytic leukaemia: correlation with clinical stage.

A search for a correlation between the clinical stage of chronic lymphocytic leukaemia (CLL) and the pattern of immunoglobulin heavy chain gene rearrangements was undertaken. DNA samples from the leukaemic cells of 38 CLL patients were analysed by Southern blot hybridization. Using probes for the immunoglobulin heavy chain J (JH) and C mu regions a marked heterogeneity of the hybridization patterns was observed in both regions. The number of JH hybridization bands varied from one to four and more than two were found in 58% of the patients. In 42% of the patients no germline JH genes were found. One to three additional C mu bands were observed in 34%, but the germline was preserved in all samples. There was no correlation between the clinical stage and the number of hybridizing JH bands; however, a significant correlation was found between the loss of JH germline band or a C mu multiband pattern and advanced stage of the disease. The genetic events in the immunoglobulin genes observed in advanced CLL patients are assumed to result from clonal evolution and tumour progression.

Adult↗
PubMed1989

Aplastic crisis due to human B19 parvovirus infection in red cell pyrimidine-5'-nucleotidase deficiency.

Two siblings with chronic hemolytic anemia due to red cell pyrimidine-5'-nucleotidase (P-5'-N) deficiency, presented within a few days of each other with a febrile illness and pancytopenia. The cause of the aplastic crisis was an acute infection with human B19 parvovirus (B19 HPV) as proven by immunoelectron microscopy and DNA hybridization. This is the first report on the association of B19-HPV-related aplastic crisis with P-5'-N deficiency.

5'-Nucleotidase↗
PubMed1989

Pure red cell hypoplasia associated with polyglandular autoimmune syndrome type I.

The polyglandular autoimmune syndrome Type I is characterized by hypoparathyroidism, adrenal insufficiency, and mucocutaneous candidiasis, and may be associated with other autoimmune-mediated diseases, including pernicious anemia, chronic active hepatitis and vitiligo. We report two patients aged 7 and 15 years in whom pure red cell hypoplasia was a prominent feature of the polyglandular Type I syndrome. Hematological remission was obtained with corticosteroid treatment in one patient, and with gamma-globulin therapy in the other. These findings indicate that pure red cell hypoplasia is one of the autoimmune manifestations that may be associated with this syndrome.

Adolescent↗
PubMed1989

A search for bcl1, bcl2, and c-myc oncogene rearrangements in chronic lymphocytic leukemia.

Three cellular or putative oncogenes: c-myc, bcl1, and bcl2 were previously found to be rearranged in some B cell malignancies due to chromosomal translocations. Data concerning the role of such genetic rearrangements in B-CLL are very scanty and limited to few cases in which bcl1 rearrangements were found. We studied DNA samples from 38 cases of B-CLL by Southern blot technique in order to find out the existence and frequency of such events. No bcl1 or bcl2 rearrangements were found in any of the studied cases; thus, involvement of these genes in CLL must be rare. In one patient who had an aggressive and resistant disease, c-myc rearrangement was found.

Adult↗
PubMed1988

Cloning of cDNA encoding a 32-kDa protein. An accessory polypeptide of the H+-ATPase from chromaffin granules.

The purified H+-ATPase from chromaffin granules is composed of several polypeptides, one of which has an apparent molecular weight of 39,000. Immunoblots with the antibody against this protein and various membrane preparations showed that similar or even identical polypeptides may be associated with the H+-ATPases from synaptic vesicle, kidney microsomes, and lysosomes. A cDNA library was constructed from bovine adrenal medulla, and the cDNA encoding the polypeptide was isolated and sequenced. Search in DNA and protein data banks revealed no significant homology to known genes. Hydrophobicity plot revealed no obvious transmembrane segments with the exception of one stretch of hydrophobic and neutral amino acid starting at leucine 16. The cDNA was shown to encode the entire polypeptide by the virtue of an amino acid sequence corresponding to the N terminus of the open reading frame and by subunit and site-specific antibodies. The cDNA was cloned into an expression vector, transcribed by T7 polymerase, and translated by reticulocyte lysate. Even though the cDNA encodes a protein with a molecular weight of 31,495, the translation product comigrated on sodium dodecyl sulfate gels with the subunit of the purified H+-ATPase. In line with several other subunits of vacuolar H+-ATPases, no signal sequence was detected in the translated gene. Northern blots revealed the presence of a single mRNA of about 1.6 kb in bovine adrenal medulla. However, liver, lung, and kidney may contain additional mRNA of about 1.7 kb.

Adrenal Medulla↗