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Biomedical subjects

R Berger

Publications and source records attributed to R Berger.

At least 397 records · Page 22Linked to original sources
PubMed1993

A simple method for prenatal diagnosis of trisomy 21 on uncultured amniocytes.

Prenatal diagnosis of trisomy 21 would be easier if fluorescence in situ hybridization (FISH) could be applied to interphase nuclei. Therefore, we prepared a chromosome-21-specific probe by in vitro enzymatic amplification of inter-Alu sequences from YAC clones previously localized to this chromosome. This probe was used for FISH on 22 uncultured amniocyte samples. An easy, rapid, and safe technique is proposed for the prenatal diagnosis of trisomy 21.

Amniocentesis↗
PubMed1993

Hereditary tyrosinemia type I. Self-induced correction of the fumarylacetoacetase defect.

Two Norwegian patients with chronic tyrosinemia type I showed > 50% residual fumarylacetoacetase activity in liver samples obtained during liver transplantation. The enzyme characteristics of both patients were comparable with those of a normal control. Immunohistochemistry on liver sections from these patients and from three other Norwegian tyrosinemia patients revealed a mosaicism of fumarylacetoacetase immunoreactivity corresponding completely or partly to some of the regenerating nodules. This appearance of enzyme protein is presumably induced by the disease process. The mechanism involved remains unclear and could be caused by a genetic alteration, regained translation of messenger RNA, or to enhanced stability of an abnormal enzyme.

Amino Acid Metabolism, Inborn Errors↗
PubMed1993

Rearrangements of the retinoic acid receptor alpha and promyelocytic leukemia zinc finger genes resulting from t(11;17)(q23;q21) in a patient with acute promyelocytic leukemia.

Cytogenetic study of a patient with acute promyelocytic leukemia (APL) showed an unusual karyotype 46,xy,t(11;17) (q23;21) without apparent rearrangement of chromosome 15. Molecular studies showed rearrangements of the retinoic acid receptor alpha (RAR alpha) gene but no rearrangement of the promyelocytic leukemia gene consistent with the cytogenetic data. Similar to t(15;17) APL, all-trans retinoic acid treatment in this patient produced an early leukocytosis which was followed by a myeloid maturation, but the patient died too early to achieve remission. Further molecular analysis of this patient showed a rearrangement between the RAR alpha gene and a newly discovered zinc finger gene named PLZF (promyelocytic leukemia zinc finger). The fusion PLZF-RAR alpha gene found in this case, was not found in DNA obtained from the bone marrow of normals, APL with t(15;17) and in one patient with AML-M2 with a t(11;17). Fluorescence in situ hybridization using a PLZF specific probe localized the PLZF gene to chromosomal band 11q23.1. Partial exon/intron structure of the PLZF gene flanking the break point on chromosome 11 was also established and the breakpoint within the RAR alpha gene was mapped approximately 2 kb downstream of the exon encoding the 5' untranslated region and the unique A2 domain of the RAR alpha 2 isoform.

Aged↗
PubMed1993

Postnatal glucose kinetics in newborns of tightly controlled insulin-dependent diabetic mothers.

Infants of diabetic mothers are at risk of developing hypoglycemia postnatally. Strict control of blood glucose during pregnancy might result in adequate glucose homeostasis in the neonate. We followed 15 mother-infant pairs from the beginning of pregnancy until birth. Glucose kinetics in the infants were measured on the first day of life, using a stable isotope dilution technique. Furthermore, levels of alternative substrates, FFA, and ketone bodies were measured. All infants received i.v. glucose from birth onward at a rate of 3.4 +/- 0.7 mg/kg/min (mean +/- SD). There was no relationship between the parameters of control of the insulin-dependent diabetes mellitus in the mothers and glucose kinetics in their infants. Glucose turnover was 5.2 +/- 1.1 mg/kg/min, glucose production rate (GPR) was 1.8 +/- 1.1 mg/kg/min. GPR was significantly lower in the infants studied at the end of the first day of life (p < 0.01), irrespective of the glucose infusion rate. Furthermore, the lower GPR was associated with an increased concentration of ketone bodies, suggesting an increased production of ketone bodies in these infants. The relatively high GPR measured in the infants who were studied in the first hours postnatally may be the result of postnatal hormonal stimulation of glycogenolysis and/or gluconeogenesis. From this study, we conclude that glucose kinetics in infants of tightly controlled diabetic mothers appear to be normal. Interestingly, despite the near-optimal insulin therapy in the mothers, there is a relationship between the SD scores of birth weight and the mean 3rd-trimester blood glucose values.

Aging↗
PubMed1993

Differences between blastic chronic myeloid leukemia and Ph-positive acute leukemia.

Cytogenetic and molecular characteristics of chronic myeloid leukemia in blast crisis and Ph-positive acute leukemia are compared. The main differences relate to the presence of Ph-negative metaphases at diagnosis and the disappearance of Ph in complete remission in acute leukemia, and the localization of the chromosome breakpoints in the BCR gene, in the bcr segment in chronic leukemia and in the first intron of the BCR gene in 50% of acute leukemias. The profiles of these abnormalities, as well as the types of additional chromosome changes, are not sufficient to distinguish between the two disorders in every patient. The distinction between these two entities, which is possible in the majority of patients, will be improved by results of experimental work currently in progress in many laboratories.

Biomarkers, Tumor↗
PubMed1993

A novel translocation, t(9;11)(q33;q23) involving the HRX gene in an acute monocytic leukemia.

A t(9;11)(q33;q23) has been detected by chromosome painting with chromosome 11- and chromosome 9-specific probes in blast cells of a child with acute monocytic leukemia. Using a YAC clone spanning the usual breakpoint region of translocations of acute leukemias, it was shown that the breakpoint was effectively within the same region of the band 11q23. This was confirmed by Southern blot studies that showed the localization of the translocation breakpoint between the 6th and 8th exons of the HRX gene. The implication of the HRX gene in t(9;11)(q33;q23) is a novel example of the diversity of translocations involving this gene in hemopoietic disorders. Sequencing DNA in the vicinity of the breakpoints should help to understand the reason of the localization of the recombination hot spot at band 11q23.

Adult↗
PubMed1993

Cerebral energy metabolism in fetal guinea pigs during moderate maternal hypoxemia at 0.75 of gestation.

There is evidence from fetal sheep near term that cerebral oxygen delivery decreases during a moderate maternal hypoxemia, whereas cerebral oxygen consumption is maintained. However, since in immature fetuses circulatory centralization may be in part ineffective, cerebral concentrations of high-energy phosphates may fall during a moderate maternal hypoxemia due to an insufficient cerebral oxygen supply. On the other hand anaerobic glycolysis may accelerate to prevent the depletion of high-energy phosphates. To determine, whether or not there is an energy failure in the immature fetal brain in this situation, we studied the effects of 60 min moderate maternal hypoxemia on cerebral concentrations of high-energy phosphates and glycolytic intermediates in fetal guinea pigs at 0.75 gestation. Maternal hypoxemia resulted in no change in fetal mixed arterio-venous pH (7.41 +/- 0.05 vs. 7.38 +/- 0.05; n.s.) or PCO2 (39.0 +/- 4.2 vs. 36.4 +/- 5.6 mmHg; n.s.), but in a fall in fetal PO2 (17.3 +/- 2.2 vs. 11.2 +/- 1.9 mmHg; P < 0.01). There was an increase in fetal cerebral concentrations of lactate (1.50 +/- 0.24 vs. 2.82 +/- 0.91 mumol/g; P < 0.01), whereas those of high-energy phosphates remained unchanged. From these results we conclude that during moderate isocapnic hypoxemia cerebral energy metabolism of immature fetal guinea pigs is maintained by an acceleration of the anaerobic glycolytic rate.

Animals↗
PubMed1993

Nonradioactive gel mobility shift assay using chemiluminescent detection.

A nonradioactive gel mobility shift assay using chemiluminescent detection following semidry transfer to nylon membranes is described. The procedure utilizes digoxigenin-labeled oligonucleotides in conjunction with anti-digoxigenin antibody Fab fragments coupled to alkaline phosphatase. Detection of alkaline phosphatase is by autoradiography of the chemiluminescence produced during enzymatic dephosphorylation of a dioxetane substrate. This method offers similar sensitivity to radioactive methods while having the advantages of multiple exposures, faster processing, stability of labeled oligonucleotides and safety associated with nonradioactive methods of detection.

DNA-Binding Proteins↗
PubMed1993

Translocation t(3;22)(q27;q11) in non-Hodgkin's malignant lymphoma: chromosome painting and molecular studies.

Translocation t(3;22)(q27;q11) has recently been recognized as a recurrent abnormality in non-Hodgkin's malignant lymphoma (NHL). A new gene, LAZ3, has been shown to be involved in NHL with 3q27 rearrangement. Two patients with B-cell NHL were studied by chromosome painting and Southern blot analysis. Fluorescence in situ hybridization to metaphase chromosomes was shown to be an easy way to detect the chromosomal abnormality even in metaphase cells with poorly defined chromosomes. The gene LAZ3 was rearranged in one patient in the 'major translocation cluster region'. The comigration of rearranged LAZ3 and of IGL bands suggests that the translocation resulted in the juxtaposition of the two genes. This juxtaposition makes possible a potential deregulation of the LAZ3 gene expression, as previously shown for the MYC and BCL2 genes in Burkitt and follicular lymphoma translocations.

Aged↗
PubMed1993

Whole arm translocation t(17;18): a non-random abnormality of myeloid cell proliferation.

Whole arm translocation t(17;18) was detected in two patients, one with acute monocytic leukemia and the other with acute transformation of chronic myelocytic leukemia. Dual-color fluorescence in situ hybridization (FISH) to interphase nuclei with alphoid probes specific to chromosomes 17 and 18 showed the presence of two very close spots. This feature was interpreted as the conservation of the pericentromeric region of the two chromosomes involved in the translocation. The present cases add to eight previously reported other patients with whole arm translocation t(17;18) (one with FISH studies). Since these patients had either myeloid leukemia or myelodysplastic syndrome, it is suggested that the t(17;18)(p10;q10) translocation is a new non-random abnormality associated with myeloid cell proliferations.

Adult↗
PubMed1993

[Late diagnosis of classical galactosemia. An adult with special biochemistry].

The atypical case history of a galactosemic patient who was not recognized as such until his 22nd year is described. As in classical galactosemia there was not found any galactose-1-phosphate uridyl transferase activity in the erythrocytes. However, after the patient was on a galactose-free diet, there was no demonstrable elevation of galactose-1-phosphate in the erythrocytes. We would advocate a limited screening on galactosemia.

Adult↗
PubMed1993

[Pulse therapy (high doses of venous methylprednisolone) in children with rheumatic carditis. Prospective study of 40 episodes].

PURPOSE: To use corticosteroids in a shorter period to treat rheumatic carditis, keeping the patient in the hospital; and verify the time interval of normalization of rheumatic activity tests with this method. METHODS: In 36 patients (40 episodes) intravenous methyl-prednisolone (1g/day) was administered. The number of series ranged from two to four, according to severity of the disease. The ages ranged from 6 to 17 years old, all of them fulfilled the criteria of Jones for diagnosis of rheumatic fever. They were submitted to treatment to eradicate the streptococcus, worms, PPD and dental focus extraction, before use of corticosteroids. RESULTS: In all patients the signals and symptoms of heart failure improved. In six cases occurred complications during pulse therapy that were easily controlled with clinical measures. Two series of methylprednisolone were used in 10 children, three in nine and four in 21 episodes. Eight patients were sent to valve replacement. The interval of time that laboratory tests of rheumatic activity became negative was 41.2 +/- 13.3 days. CONCLUSION: Using this IV corticotherapy it was possible decrease the amount of days of this medication, keeping the patient in the hospital. In this way we eliminate the problem of interruption of the treatment. There was not significative difference between oral and IV corticotherapy in order to the laboratory tests become negative.

Adolescent↗
PubMed1993

Identification of class-mu glutathione transferase genes GSTM1-GSTM5 on human chromosome 1p13.

The GSTM1, GSTM2, GSTM3, GSTM4, and GSTM5 glutathione transferase genes have been mapped to human chromosome 1 by using locus-specific PCR primer pairs spanning exon 6, intron 6, and exon 7, as probes on DNA from human/hamster somatic cell hybrids. For GSTM1, the assignment was confirmed by Southern blot hybridization to a pair of 12.5/2.4-kb HindIII fragments. The GSTM1-specific primer pairs can be used to identify individuals carrying non-null GSTM1 alleles. The organization of these five genes was confirmed by the isolation of a yeast artificial chromosome clone (GSTM-YAC2) that contains all five genes. With this clone, the location of the GSTM1-GSTM5 gene cluster on chromosome 1 was confirmed by fluorescence in situ hybridization. Both regional assignment using the fractional length method and examination of probe signal with reference to R-banded chromosomes induced by BrdU places the gene cluster in or near the 1p13.3 region. The close physical proximity of the GSTM1 and GSTM2 loci, which share 99% nucleotide sequence identity over 460 nucleotides of 3'-untranslated mRNA, suggests that the GSTM1-null allele may result from unequal crossing-over.

Animals↗
PubMed1993

Localization of the chromosome 15 breakpoints and expression of multiple PML-RAR alpha transcripts in acute promyelocytic leukemia: a study of 28 Chinese patients.

Translocation (15;17)(q22;q12-q21) is a chromosome aberration specifically found in acute promyelocytic leukemia (APL), that generates a chimeric gene between the promyelocytic leukemia (PML) gene on chromosome 15 and the retinoic acid receptor alpha (RARA) gene, on chromosome 17. In the course of molecular investigations of a series of 28 Chinese patients with APL, we have simultaneously used Southern blot and reverse transcriptase polymerase chain reaction (RT-PCR) analysis to characterize the PML gene breakpoints on chromosome 15 and identify PML-RARA fusion transcripts. Our results confirmed the existence of the three recently described bcr1, bcr2, and bcr3 breakpoint cluster regions. In addition, structural data provided by PML-RARA transcripts allowed us to more accurately locate the 3' borders of clusters bcr1 and bcr3. Moreover, our data suggest a preferential localization of the breakpoints within bcr1 and bcr3. The primary structure of a 1.4 kb DNA segment flanking the 5' part of the PML gene and that of the bcr3 cluster (2.1 kb) were also established.

Base Sequence↗
PubMed1993

BCL2 gene activation and protein expression in follicular lymphoma: a report on 64 cases.

Rearrangements of the BCL2 gene and expression of bcl-2 protein were analyzed in a series of 64 cases of follicular lymphomas in order to establish a relationship between the rearrangements and the protein overexpression. Of the 64 cases, 41 showed BCL2 rearrangement involving one of the three breakpoint clusters: 30 in mbr, eight in mcr, and three in vcr. A double rearrangement mbr+vcr was detected in two cases. Twenty cases with bcl-2 protein expression in tumor cells exhibited no apparent rearrangement, suggesting the possible existence of other mechanisms activating the gene. Interestingly, expression of the LMP1 protein, the Epstein-Barr virus (EBV) encoded gene, whose capacity to induce BCL2 has been recently demonstrated, was only found in 2/41 cases in which BCL2 was rearranged. These data suggest that EBV infection is not an important mechanism in the activation of BCL2 in follicular lymphoma.

Antigens, Viral↗
PubMed1993

Familial case of 46,XX male and 46,XX true hermaphrodite associated with a paternal-derived SRY-bearing X chromosome.

The human testis-determining gene was recently isolated from a 35 kb region on the human Y chromosome which was present in four sex-reversed individuals, three XX males and one true hermaphrodite. One of the XX males and the true hermaphrodite were sibs. A more detailed molecular analysis of these two patients and their family for Y-DNA sequences including the testis-determining gene, SRY was performed. The father was found to harbor two copies of SRY, one on his Y chromosome and the other on his X chromosome located at Xp22 determined by in situ hybridization. Somatic cell hybrids were generated from peripheral blood lymphocytes. Analysis of Y chromosome-negative somatic cell hybrids from the XX male, the true hermaphrodite and their father, revealed that both the X and Y pseudo-autosomal boundaries were present. The present of both boundaries suggests than an unequal interchange of X and Y material occurred with the cross-over breakpoint located within the X pseudo-autosomal region. The paternal SRY-bearing X chromosome was transmitted to two of his children, a 46 XX true hermaphrodite and a 46,XX male. The presence of SRY on an X chromosome associated with two sex phenotypes strongly suggests that the phenotypic variability was caused by differential inactivation of the SRY-bearing X chromosome, thereby influencing SRY expression.

Base Sequence↗
PubMed1993

Characterization of translocation t(1;14)(p32;q11) in a T and in a B acute leukemia.

The TAL1 locus on chromosome band 1p32 is rearranged in 15 to 29% of human T-cell acute lymphoblastic leukemias (T-ALLs). These alterations consist of either a tald submicroscopic deletion (12-26% of T-ALL) or a t(1;14)(p32;q11) chromosomal translocation (3% of childhood T-ALL). Both types of alterations preferentially affect the 5' part of the TAL1 locus. Their main consequence appears to be transcriptional activation of the TAL1 gene. We have characterized two cases of t(1;14)(p32;q11) in ALL. Both affect the TCR delta gene segments at 14q11 and the 5' part of the TAL1 locus at 1p32. The first case represented a 'classical' t(1;14), associated with T-ALL. Its analysis indicates the use of a recombination signal-like sequence localized in the third exon of TAL1 in the translocation process. In the other case, the rearrangement to the D delta region occurred 5' to the TAL1 transcription start sites. This case exhibited a B-lymphoid immunophenotype thus suggesting that the putative oncogenicity of TAL1 activation is not restricted to T-cell malignancies.

Adult↗