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Biomedical subjects

R Berger

Publications and source records attributed to R Berger.

At least 235 records · Page 13Linked to original sources
PubMed1996

Prognostic impact of big endothelin-1 plasma concentrations compared with invasive hemodynamic evaluation in severe heart failure.

OBJECTIVES: This study sought to test the hypothesis that big endothelin-1 plasma levels in advanced heart failure are related to survival. BACKGROUND: In heart failure, production of the potent vasoconstrictor endothelin-1 is increased. Because elevation of immunoreactive endothelin-1 in severe heart failure is primarily related to the precursor "big" endothelin-1, increased big endothelin-1 levels may be associated with a poor prognosis. METHODS: Plasma big endothelin-1 concentrations, in addition to 16 clinical, hemodynamic and neurohumoral variables, were obtained from 113 patients (mean age -=/[SEM] 53 +/- 1 years) with left ventricular ejection fraction <20% and were related to 1-year mortality by a stepwise Cox regression multivariate analysis. RESULTS: Plasma big endothelin-1 concentrations were significantly higher in patients with moderate and severe heart failure than in those with mild heart failure (4.5 +/- 0.4 and 6.0 +/- 0.1 vs. 2.7 +/- 0.1 fmol/ml, p = 0.0001, respectively) and lower in 58 one-year survivors than in 29 nonsurvivors (2.6 +/- 0.1 vs. 5.9 +/- .04 fmol/ml, p = 0.0001) and 26 heart transplant recipients. By univariate analysis, big endothelin-1 plasma concentrations (p < 0.0001), functional class, daily furosemide dose, left ventricular ejection fraction, most hemodynamic variables and plasma atrial natriuretic peptide, sodium renin activity and aldosterone levels were all related to mortality, but only functional class provided additional prognostic information when big endothelin-1 plasma levels were entered into the multivariate model. CONCLUSIONS: In advanced heart failure, plasma big endothelin-1 is strongly related to survival and appears to predict 1-year mortality better than hemodynamic variables and levels of atrial natriuretic peptide, an established neurohumoral prognostic marker in chronic heart failure.

Adult↗
PubMed1996

Ontogenetic differences in energy metabolism and inhibition of protein synthesis in hippocampal slices during in vitro ischemia and 24 h of recovery.

The present study was designed to clarify whether ontogenetic differences in the vulnerability of the brain towards hypoxic-ischemic insults are only caused by the low cerebral energy demand of immature animals or whether there are additional mechanisms, such as protein synthesis (PSR), that may be involved in this phenomenon. We therefore measured tissue levels of adenylates and PSR in hippocampal slices from immature (E40) and mature (E60) guinea pigs fetuses and from adult guinea pigs during in vitro ischemia and 24 h of recovery using a recently modified method. Hippocampal slices were incubated in a temperature controlled flow-through chamber, gassed with 95% O2/5% CO2. In vitro ischemia was induced by transferring slices to a glucose-free artificial cerebrospinal fluid (aCSF) equilibrated with 95% N2/5% CO2. The duration of ischemia ranged from 10 to 40 min. Adenylates were measured by HPLC after extraction with perchloric acid. PSR was evaluated as the incorporation rate of [14C]leucine into proteins. Under control conditions, tissue levels in adenylates did not change, whereas PSR increased slightly in hippocampal slices from mature fetuses and adult animals during a 24-h control incubation period. In slices from immature fetuses ATP levels were only maintained for 2 h. During in vitro ischemia the decline in ATP, total adenylate pool, and adenylate energy charge was much slower in slices from immature fetuses than in slices from mature fetuses or adults. After in vitro ischemia, ATP and the total adenylate pool did not completely recover in mature fetuses and adults, whereas adenylate energy charge almost returned to control values independently of the developmental stage. Two hours after in vitro ischemia PSR was undisturbed in slices from immature fetuses, but severely inhibited in slices from mature fetuses and adults. With ongoing recovery, PSR in mature fetuses returned to control values, while in adults it was still inhibited even 24 h after in vitro ischemia. From these results we conclude that hippocampal slices prepared from mature guinea pig fetuses as well as from adult guinea pigs can be held metabolically stable during long-term incubation using a recently modified technique. However, in slices from immature fetuses a stable energy state could not be maintained for more than 2 h. We further conclude that postischemic disturbances in PSR closely reflect the ontogenetic changes in the vulnerability of the brain to ischemia and that low energy metabolism is certainly not the only cause of the increased vulnerability of the fetal brain to ischemia.

Adenosine Triphosphate↗
PubMed1996

Inactivation of the P16INK4/MTS1 gene by a chromosome translocation t(9;14)(p21-22;q11) in an acute lymphoblastic leukemia of B-cell type.

We have reported previously a preliminary study of a t(9;14)(p21-22; q11) in B-cell acute lymphoblastic leukemia. This translocation had rearranged the TCRA/D locus on chromosome band 14q11 and the locus encoding the tumor suppressor gene P16INK4/MTS1 (P16) on band 9p21 (D. Duro et al., Oncogene, 11: 21-29, 1995). In the present report, the breakpoints were precisely localized on each chromosome partner. On the 14q- derivative, the sequence derived from chromosome 9 was interrupted at 1.0 kb upstream of the first exon of P16, close to a consensus recombination heptamer, CACTGTG. In addition, the chromosome 14 breakpoint was localized at the end of the TCRD2 (delta 2) segment, and 22 residues with unknown origin were present at the translocation junction. On the 9p+ derivative, chromosome 9 sequences were in continuity with those displaced onto chromosome 14, and the 14q11 breakpoint was located within TCRJA29 segment. These features are consistent with aberrant activity of the TCR gene recombinase complex. Although all three coding exons of P16 were displaced onto the chromosome 14q-derivative, no P16 transcript was detected in the leukemic cells. Because the region spanning the P16 exon 1 was not inactivated by methylation and because the other P16 allele was deleted, the implication is that the chromosome breakpoint was likely to disrupt regulatory elements involved in the normal expression of the gene. As a whole, then, our results show that translocations affecting band 9p21 can participate to the inactivation of P16, thus justifying a systematic survey of translocations of the 9p21 band in acute lymphoblastic leukemia.

Base Sequence↗
PubMed1996

Fumarylacetoacetase mutations in tyrosinaemia type I.

Sixty-two hereditary tyrosinaemia type I (HT1) patients of various ethnic origins were classified clinically into acute, chronic, or intermediate phenotypes and screened for the 14 published causal mutations in the fumarylacetoacetase (FAH) gene. Restriction analysis of PCR amplified genomic DNA identified 74% of the mutated alleles. IVS12 + 5G --> A, predominant in the French Canadian HT1 patients, was the most common mutation found in 32 alleles in patients from Europe, Pakistan, Turkey, and the United States. IVS6-1G --> T, encountered in 14 alleles, was common in Central and Western Europe. There was an apparent "Scandinavian" 1009G --> A combined splice and missense mutation (12 alleles), a "Pakistani" 192G --> T splice mutation (11 alleles), a "Turkish" D233V mutation (6 alleles), and a "Finnish" or northern European W262X mutation (7 alleles). The remaining mutations were rare. Some of the mutations seem to predispose for acute and other for more chronic forms of HT1, but in our material no clearcut genotype phenotype correlation could be established.

Alleles↗
PubMed1996

Chromosome microdissection in leukemia: a powerful tool for the analysis of complex chromosomal rearrangements.

In many human cancers the presence of marker chromosomes or unbalanced translocations prevents complete karyotypic analysis. Chromosome microdissection has become an increasingly important method for assessing chromosome rearrangements. However, most studies using chromosome microdissection have been carried out on established cancer cell lines that provide an unlimited supply of abnormal metaphase cells. We have routinely performed microdissection of as few as three marker chromosome copies from short-term cultures of acute myeloid leukemias, followed by in vitro DNA amplification and fluorescence in situ hybridization (FISH) to normal metaphase spreads. Using this type of "reverse chromosome painting," we were able to characterize precisely the chromosomal constitution of each marker chromosome in the samples, confirming the diagnostic usefulness of microdissection in cancer cytogenetics. In addition, in one leukemia with atypical cytological features, microdissection enabled us to detect a novel retinoic acid receptor alpha gene rearrangement.

Acute Disease↗
PubMed1996

Comparison of nonrandomized trials with slow-release sodium fluoride with a randomized placebo-controlled trial in postmenopausal osteoporosis.

The results of slow-release sodium fluoride (SR-NaF) treatment in two nonrandomized trials involving 65 patients with postmenopausal osteoporosis from the primary site and 121 patients from collaborative sites were compared with those obtained from 54 treated patients and 56 patients taking placebo from a randomized controlled trial. Spinal fracture data were analyzed separately in mild to moderate bone loss of lumbar spine (baseline L2-L4 bone density [BD] > or = 65% young normal) and in severe bone loss (BD < 65%). Since demographic and fracture data were similar among fluoride-treated patients from the three trials at each stratum of bone loss, their data were combined. In mild to moderate bone loss, SR-NaF treatment in the combined group virtually eliminated new spinal fractures with 96.6% of patients remaining fracture-free. The Fluoride group had a markedly lower individual vertebral fracture rate (0.025 vs. 0.188/patient year, p = 0.0001) and group vertebral fracture rate (0.029 vs. 0.175/patient year, relative risk [RR] 0.12, p = 0.0001) than the Placebo group. In severe bone loss, the combined treated group had a significantly lower new spinal fracture rate than the Placebo group, although the differences were not as marked (group vertebral fracture rate of 0.150 vs. 0.276/patient year, RR 0.54, p = 0.03). In the combined fluoride-treated group, the L2-L4 bone mass rose by 4-6%/year for 4 years, and the femoral neck BD increased by 1-2%/year during first 2 years. The radial shaft BD did not change. The Placebo group did not show a change in bone mass at any site. The prevalence (percentage) of patients with related gastrointestinal side effects and nonvertebral fracture rates did not differ significantly between the combined SR-NaF group and the Placebo group (hip fracture rate of 0.0045/patient year in SR-NaF and 0.0053/patient year in Placebo; appendicular fracture other than hip (see text) rate of 0.0193/patient year in SR-NaF and 0.0159/patient year in Placebo). A subgroup analysis showed a low baseline L2-L4 BD, high prevalent spinal fractures, and reduced body weight to be important determinants of the development of spinal fracture during SR-NaF treatment. Concomitant medications (estrogen, vitamin D, thiazide and thyroid hormone) were not independent predictors of the spinal fracture risk. Only 17% of fluoride-treated patients were nonresponders (new spinal fractures or a fall/no change in L2-L4 bone mass). Thus, the effects of SR-NaF treatment on the spinal fracture rate from nonrandomized trials were similar to those of the treated group of the randomized trial but different from those of the Placebo group. The similarity of response of nonrandomized trials with that of the randomized controlled trial and the resultant combined analysis further validate the efficacy and safety of SR-NaF in the treatment of postmenopausal osteoporosis.

Bone Density↗
PubMed1996

Hereditary tyrosinemia type 1: novel missense, nonsense and splice consensus mutations in the human fumarylacetoacetate hydrolase gene; variability of the genotype-phenotype relationship.

The complete fumarylacetoacetate hydrolase (FAH) genotype of probands of thirteen unrelated families with hereditary tyrosinemia type 1 (HT 1) was established. The screening was performed by analysis of exons 2-14 of the FAH gene by using the polymerase chain reaction (PCR) and of the mRNA by reverse transcription/PCR. Nine different mutations were identified, of which six are novel. Three mutations involve consensus sequences for correct splicing, viz. IVS 6-1 (g-t), IVS 7-1 (g-a) and IVS 12 + 5 (g-a). Two missense mutations (C193R and G369V) and three nonsense mutations (R237X, E357X and E364X) were found. One silent mutation N232N was associated with the skipping of exon 8 from the FAH mRNA. Analysis of the effect of the respective mutations on the FAH mRNA showed a strong reduction of FAH mRNA levels in association with the nonsense mutations, and normal levels with the missense mutations. The splice consensus mutations give deletions of complete or small parts of exon sequences from the FAH mRNA. Data suggest a founder effect for several of the mutations, with a frequency for both the IVS 6-1 (g-t) and IVS 12 + 5 (g-a) mutations of approximately 30% in the HT 1 probands. No strict correlation between genotype and phenotype, i.e. the acute, subacute or chronic form of HT 1, was evident.

Alleles↗
PubMed1996

Secondary acute myeloblastic leukemia with t(16;21) (q24;q22). involving the AML1 gene.

A t(16;21) (q24;122) translocation was detected by fluorescence in situ hybridization in a patient with acute myeloblastic leukemia previously treated for malignant lymphoma. While the breakpoint on chromosome 21 was within the AML1 gene as determined by FISH, the gene partner on chromosome 16 could not be identified. Band 16q24 appears to be rearranged in several types of myeloid proliferation and a review of the literature shows that these rearrangements most often occur in secondary leukemia and myelodysplastic syndrome or are part of complex chromosomal rearrangements.

Adult↗
PubMed1996

Childhood B-cell acute lymphoblastic leukemia with FAB-L1 morphology and a t(9;11) translocation involving the MLL gene.

The t(9;11) (p21-22;q23) translocation is frequently associated with acute monoblastic leukemia but may occasionally be seen in patients with acute lymphoblastic leukemia (ALL). We report a case of childhood ALL associated with t(9;11) (p21-22;q23) as the unique recurring chromosomal abnormality. A 3-month-old girl presented with "lymphomatous" ALL (renal enlargement), a high leukocyte count and central nervous system (CNS) involvement. Leukemic cell typing revealed a sIg+ B-cell immunophenotype without CD10 and CD34 antigenic expression while the blast cell morphology was of the FAB-L1 type. Splitting of a YAC encompassing the MLL gene was shown by fluorescence in situ hybridization (FISH) studies of the patient's metaphase chromosomes. Rearrangement of the MLL gene was confirmed by Southern blot analysis. Despite treatment with an hyperintensive polychemotherapeutic regimen, the patient achieved a complete remission but relapsed 9 months later. These results provide further evidence that the t(9;11) may be observed in ALL, involves the MLL gene and is associated with a poor outcome. Moreover, this observation clearly illustrates that sIg+ B-cell ALL is not necessarily associated with a Burkitt (L3) morphology.

B-Lymphocytes↗
PubMed1996

Clonal chromosome abnormalities in Fanconi anemia.

Fanconi anemia (FA) belongs to the chromosomal instability syndromes and frequently evolves toward hematopoietic malignancy. While the recent isolation of one of the genes of FA allows to view to gene therapy, the best treatment is currently bone marrow transplantation. In this review, the data on clonal chromosome abnormalities of FA patients are presented and their significance discussed in the context of the disease.

Child↗
PubMed1996

Dual localization of the human gene encoding hnRNP I/PTB protein to chromosomes 19p13.3 and 14q23.

A cDNA probe representative of the human hnRNP I/PTB gene was used to perform fluorescence in situ hybridization (FISH) on metaphases of human chromosomes. A new localization was found on band 19p13.3 in addition to the previously reported localization to band 14q23. Identical results were obtained when FISH analysis was repeated with probes covering different parts of the hnRNP I cDNA clone. This supported the notion that most, if not all, of the sequences of the different parts of this clone are present on both chromosomes. Moreover, Southern blot analysis of DNAs from interspecies somatic hybrids containing chromosomes 19 and 14 revealed that the whole hnRNP I cDNA probe generated very similar patterns in each hybrid DNA. These data suggest that two closely related copies of the hnRNP I gene exist in the human genome.

Blotting, Southern↗
PubMed1996

Presence of three recurrent chromosomal reaarrangements, t(2;3)(p12;q37), del(8)(q24), and t(14;18), in an acute lymphoblastic leukemia.

A complex chromosomal abnormality associating three recurrent rearrangements, t(2;3)((p12;q37), del (8)(q24) and t(14;18)(q32;q21), was detected in a patient with acute lymphoblastic leukemia of the Burkitt type. Southern blot studies showed rearrangements of the MYC, BCL2, and JH genes, thus confirming the cytogenetic data. However, no rearrangement of the LAZ3/BCL6 gene, normally localized on band 3q27, could be detected. The simultaneous presence of three recurrent rearrangements specific for lymphoid malignancies addresses the question of their timing in the malignant process and the prognostic significance of the association of such anomalies.

Adult↗
PubMed1996

Blood pH in the umbilical artery at birth: an analysis of data from patients delivered in Hesse between 1986 and 1989.

OBJECTIVE: Measuring blood pH in the umbilical artery at birth is an important means of maintaining obstetrical quality. Consideration of the interrelations between low umbilical blood pH and perinatal risk factors may enable obstetricians to provide better care of the mother and child during pregnancy and delivery. We therefore studied the incidence of measuring blood pH at birth, the distribution and normal range of umbilical blood pH at birth, and the correlation between umbilical blood pH and pre-, sub-, and postnatal risk factors in patients delivered in Hesse between 1986 and 1989. SUBJECTS: Over this period 2053 women were delivered between 30 and 32 weeks and 128,654 between 39 and 41 weeks of gestation. Each of these two groups was further subdivided according to the mode of delivery (spontaneous vaginal delivery; operative vaginal delivery; Cesarean section). Of the patients delivered between 39 and 41 weeks of gestation, 24,315 had exhibited no risk factors during pregnancy or delivery. RESULTS: The overall incidence of measuring umbilical blood pH at birth was about 70%, whereas pH measurements were taken in only 60% of preterm babies delivered vaginally. The percentage of preterm neonates with an umbilical blood pH < 7.10 was considerably higher than that of term fetuses (5.0% vs. 1.3%). Of the neonates born of women displaying no risk factors during pregnancy and delivery, 22.4% had an umbilical blood pH < or = 7.25. In patients delivered at term hardly any correlation was found between prenatal risk factors and umbilical blood pH. This contrasted to the situation in patients delivered between 30 and 32 weeks of gestation. In most subgroups a close correlation could be demonstrated between umbilical blood pH and both sub- and postnatal risk factors. No correlation was detected between umbilical blood pH and perinatal mortality. CONCLUSION: In view of the aim of maintaining and improving obstetrical quality in Hesse, the incidence of measuring umbilical blood pH at birth should be increased, especially in preterm fetuses. Since 22.4% of all babies from patients exhibiting no risk factors during pregnancy and delivery had an umbilical blood pH < or = 7.25, we have to reflect once again on the range of 'normal' umbilical blood pH at birth. Consideration of the various interrelations between umbilical blood pH and pre-, sub-, and postnatal risk factors demonstrated in this study may enable obstetricians to reduce the incidence of severely compromised fetuses at birth.

Delivery, Obstetric↗
PubMed1996

Local cerebral glucose utilization in fetal guinea pigs at 0.75 gestation.

OBJECTIVE: Using the 2-deoxyglucose method, measurements of local cerebral glucose utilization in large fetal animals are very difficult and expensive. To circumvent these problems we recently modified the 2-deoxyglucose method for use in the fetal guinea pig in utero (Berger et al., J Neurochem 1994; 63: 271-279). The present study was designed to measure the rates of local cerebral glucose utilization in fetal guinea pigs at 0.75 of gestation. STUDY DESIGN: After intravenous injection of 14C 2-deoxyglucose into the dams, local cerebral glucose utilization of the fetuses was measured from the time integral of the tracer in the maternal plasma and the autoradiographically determined concentration of the tracer in various parts of the fetal brain. RESULTS: Fetal cerebral glucose utilization was low as compared to adult animals and varied in different brain structures from 19 +/- 4 to 29 +/- 7 mumol/100 g/min. CONCLUSION: This study demonstrates the feasibility to measure local cerebral glucose utilization in undisturbed fetal guinea pigs in utero. We conclude that the low rate of cerebral glucose utilization and its small overall variability may reflect the neurological immaturity of the fetal brain.

Animals↗
PubMed1996

Lumpectomy and radiation treatment for invasive lobular carcinoma of the breast.

BACKGROUND: Large studies have shown a similar outcome when comparing mastectomy with lumpectomy and external beam radiation therapy in the treatment of infiltrating ductal carcinoma. However, this has not been studied extensively for invasive lobular carcinoma. We studied the pattern of recurrence and overall survival of patients treated with lumpectomy and radiation for either invasive lobular carcinoma (ILC) or combined invasive lobular carcinoma/invasive ductal carcinoma (ILC/IDC) of the breast. DESIGN: A retrospective chart review was performed for 111 patients with ILC or ILC/IDC who were diagnosed and/or treated at the university hospital between 1984 and 1994. RESULTS: Of the 111 patients, 93 had stage I or II tumors. Thirty-four patients (37%) were treated with lumpectomy and adjuvant postoperative radiotherapy with one (3%) local recurrence and a mean overall survival of 83.6 months. Fifty-nine patients (63%) were treated by modified radical mastectomy with two local recurrences (3%) and a mean overall survival of 71.7 months. CONCLUSIONS: Patients with ILC or ILC/IDC can be effectively treated with lumpectomy and radiation for stage I and II tumors while maintaining a low risk of local recurrence and equivalent overall survival.

Adult↗
PubMed1996

Identification of BTG2, an antiproliferative p53-dependent component of the DNA damage cellular response pathway.

Cell cycle regulation is critical for maintenance of genome integrity. A prominent factor that guarantees genomic stability of cells is p53 (ref. 1). The P53 gene encodes a transcription factor that has a role as a tumour suppressor. Identification of p53-target genes should provide greater insight into the molecular mechanisms that mediate the tumour suppressor activities of p53. The rodent Pc3/Tis21 gene was initially described as an immediate early gene induced by tumour promoters and growth factors in PC12 and Swiss 3T3 cells. It is expressed in a variety of cell and tissue types and encodes a remarkably labile protein. Pc3/Tis21 has a strong sequence similarity to the human antiproliferative BTG1 gene cloned from a chromosomal translocation of a B-cell chronic lymphocytic leukaemia. This similarity led us to speculate that BTG1 and the putative human homologue of Pc3/Tis21 (named BTG2) were members of a new family of genes involved in growth control and/or differentiation. This hypothesis was recently strengthened by the identification of a new antiproliferative protein, named TOB, which shares sequence similarity with BTG1 and PC3/TIS21 (ref. 7). Here, we cloned and localized the human BTG2 gene. We show that BTG2 expression is induced through a p53-dependent mechanism and that BTG2 function may be relevant to cell cycle control and cellular response to DNA damage.

3T3 Cells↗
PubMed1996

[Ophthalmologic spectrum of neurofibromatosis type 2 in childhood].

BACKGROUND: Neurofibromatosis type 2 (NF2) is a disorder with autosomal dominant inheritance which leads to tumor growth in the central and peripheral nervous system. In affected adult patients there is a typical association with ocular abnormalities like juvenile cataract. METHODS: Ophthalmologic investigation was carried out in ten children aged one to fourteen years with suspected NF2. The diagnosis was confirmed by further clinical examination and-in one patient-by segregation analysis. RESULTS: Nine of these ten children showed ocular abnormalities such as juvenile subcapsular cataracts, retinal hamartomas, optic nerve sheath tumors, fibrotic maculopathies as well as one case of a perineural calcification of the optic nerve and one case of a cerebral hamartoma on the ground of the third ventricle. DISCUSSION: In six children ophthalmological symptoms were the presenting symptom of the disease. The knowledge of these symptoms allows for the diagnosis of NF2 in children who present with isolated ocular deficits or with other typical criteria of the disease. The early diagnosis of the disease may lead to an improved prognosis with regard to preservation of hearing by surgery of bilateral vestibular schwannoma which occur in more than 90% of the NF2-patients.

Adolescent↗