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Biomedical subjects

V Klein

Publications and source records attributed to V Klein.

At least 19 recordsLinked to original sources

Low alpha-linolenic acid content of adipose breast tissue is associated with an increased risk of breast cancer.

Data derived from experimental studies suggest that alpha-linolenic acid may have a protective effect in breast cancer. Observations obtained from epidemiological studies have not allowed conclusions to be drawn about a potential protective effect of dietary alpha-linolenic acid on breast cancer, possibly because of methodological issues. This case-control study conducted in an homogeneous population from a central area in France was designed to explore the hypothesis that alpha-linolenic acid inhibits breast cancer, using fatty acid levels in adipose breast tissue as a biomarker of past qualitative dietary intake of fatty acids. Biopsies of adipose breast tissue at the time of diagnosis were obtained from 123 women with invasive non-metastatic breast carcinoma. 59 women with benign breast disease served as controls. Individual fatty acids were analysed by capillary gas chromatography. An unconditional logistic regression model was used to obtain odds ratio estimates whilst adjusting for age, menopausal status and body mass index (BMI). No association was found between fatty acids (saturates, monounsaturates, long-chain polyunsaturates n-6 or n-3) and the disease, except for alpha-linolenic acid which showed an inverse association with the risk of breast cancer. The relative risk of breast cancer for women in the highest quartile of adipose breast tissue alpha-linolenic acid level was 0.36 (95% confidence interval=0.12-1.02) compared with those in the lowest quartile (P trend=0.026), suggesting a protective effect of alpha-linolenic acid in the risk of breast cancer. The effects of dietary alpha-linolenic on the risk of breast cancer warrant further study.

Adipose Tissue↗

Morphometric analysis of bromodeoxyuridine distribution and cell density in the rat Dunning prostate tumor R3327-AT1 following treatment with radiation and/or hyperthermia.

To monitor cellular response to single doses of radiation (RT) and/or local tumor hyperthermia (LTH) proliferation kinetics were determined in the anaplastic prostate adenocarcinoma R3327-AT1 grown in Copenhagen rats. Tumor-bearing animals were injected i.v. with a bolus of bromodeoxyuridine (BrdUrd), and at defined times after treatment the tumors were surgically removed, fixed and embedded in paraffin. BrdUrd incorporated into the DNA of S-Phase nuclei was detected on 4-6 microns-thick tissue sections using a monoclonal anti-BrdUrd antibody followed by streptavidin-biotin and alkaline phosphatase as a reporter system. Cell nuclei were stained with the fluorescence dye DAPI (Diaminophenylindole). Morphometric analysis was performed using a computer-assisted Leitz-TAS/plus system. Depending on tumor size, up to 18,000 nuclei were routinely analyzed. Untreated tumors of standardized size (8-10 mm) exhibited a BrdUrd-labeling index (LI) of (6.9 +/- 1.6)%. In general, the LI was higher in the periphery than in the center, being more pronounced in larger tumors. After 6 Gy gamma-rays, the mean LI decreased to 1.8% (24 h) and rose afterwards to 5.4% by 168 h. Following LTH (43.5 degrees C, 35 min water bath), the mean LI rapidly decreased to 2% (8 h), rose to 9.8% (48 h), and plateaued at 6% after 168 h. A combined treatment consisting of irradiation (6 Gy) followed by LTH yielded smallest LI (2.4 +/- 0.18%) and lowest cell density (111 +/- 0.6 nuclei per field) by 168 h. The morphometric procedure was reliable and reproducible and can be used to characterize and compare the effects of different therapies on cell kinetics. Of particular value is that these analyses are done on an intact tissue architecture and hence enable a better interpretation of flow cytometric results of treatment-induced alterations within different topohistological regions in solid tumors. Moreover, the technique provides the basis for 3D reconstruction of the cellular activity and heterogeneity of experimental neoplasms.

Adenocarcinoma↗

Comparison of urinary free beta (hCG) and beta-core (hCG) in prenatal screening for chromosomal abnormalities.

To evaluate the potential utility of free beta (hCG) and beta-core (hCG) in a prenatal screening protocol for Down syndrome we analysed these markers in dried maternal urine specimens from 163 control, 13 Down syndrome and 5 trisomy 18 pregnancies from 8 to 25 weeks' gestation. All results are reported after normalization for urinary creatinine determined by modified Jaffe reagent assay. The correlation of urinary free beta (hCG) and urinary beta-core (hCG) was 0.61 in controls and 0.93 in Down syndrome. Median MoM values in Down syndrome were 2.42 for urinary free beta (hCG) and 2.40 for beta-core (hCG). In trisomy 18 the Median MoM was 0.35 and 0.34 for free beta (hCG) and beta-core (hCG), respectively. The degree of elevation observed in DS cases with urinary free beta (hCG) is consistent with previous reports. Studies of beta-core (hCG) in Down syndrome have yielded discrepant results. In this study, beta-core (hCG) in Down syndrome is lower than values observed in early reports but consistent with more recent reports.

Chorionic Gonadotropin, beta Subunit, Human↗

Lung function and exercise capacity in thalassaemia major.

Lung function abnormalities in thalassaemia major are various and complex; however, patients still die from cardiac lesions. This study aimed to investigate pulmonary and cardiac involvement at an early stage in thalassaemic patients and study their respective implications at rest and during exercise. Ten patients (five adults and five children) with thalassaemia major were investigated by echocardiography, lung function and exercise testing a few days after transfusion. All have had regular transfusions and chelation with deferoxamine and none had chronic pulmonary disease symptoms. Minor lung function abnormalities were found: two patients had moderate obstructive syndrome and two had a decreased carbon monoxide transfer factor. Hypoxaemia was never found at rest and no desaturation was observed at the end of exercise. Echocardiographic abnormalities were also moderate. Peak oxygen consumption (V'O2) was decreased in three adults and was lower in adults than children (means 27.7+/-4.6 and 41.1+/-4.8 mL.kg(-1).min(-2) respectively). The V'O2/cardiac frequency slope was lower in adults than children (0.25+/-0.06 versus 0.42+/-0.10 mL.kg(-1).min(-2)), whereas end-exercise breathing reserve was >40% maximal voluntary ventilation for all patients. In conclusion, none of the patients had ventilatory limitations but older patients had cardiac limitations assessed by the relationship between oxygen consumption and cardiac frequency. Exercise testing may detect cardiac impairment in thalassaemia major earlier than investigations at rest.

Adolescent↗

Prenatal diagnosis of intra-atrial cardiac echogenic foci.

Intra-atrial echogenic foci were detected in 3 out of 15,706 fetuses (prevalence 0.019 per cent). In all cases, they were located in the right atrium. Normal chromosomes and negative TORCH titres were observed in all affected cases. Fetuses with intra-atrial echogenic foci demonstrated adequate intra-uterine growth and had normal neonatal outcome. Intra-atrial echogenic foci seem to represent a normal variant of fetal cardiac development.

Echocardiography↗

Radiotherapy with high dose rate brachytherapy boost and concomitant chemotherapy for Stages IIB and III esophageal carcinoma: results of a pilot study.

PURPOSE: Radiotherapy (RT) and concomitant chemotherapy (CT) is the standard treatment for non resectable esophageal cancer. Usual total radiation dose is 50 Gy. In order to enhance local control rate a Phase II study was initiated to evaluate the feasibility of a combined treatment with an external radiation dose of 60 Gy and three cycles of concomitant CT, using the three main active drugs (CDDP, 5 FU and MMC), followed by a high dose rate (HDR) brachytherapy delivering 10 Gy. METHODS AND MATERIALS: Fifty-three patients, 48 men and 5 women, were entered in this study. Stages were evaluated with CT scan and with endoscopic sonography. Fifteen were Stage IIB, 38 Stage III. Treatment consisted of conventional fractionated RT to a total dose of 60 Gy delivered with 2 Gy per fraction, one fraction per day and five fractions per week. The CT regimen was a combination of Cisplatinum (CDDP) 20 mg/m2 and 5 Fluorouracil (5FU) 600 mg/m2 continuous infusion, from days 1-4 Mitomycin C (MMC) was given at 6 mg/m2 on day 1. Three cycles were administered on days 1, 22, and 43. Brachytherapy was delivered one week after the end of external radiation therapy. RESULTS: Full radiation therapy dose was delivered for 94% of the patients. CT compliance, evaluated on the mean relative dose-intensity was 85% for CDDP, 81% for 5FU and 51% for MMC. Overall grade 3 and 4 WHO toxicity rates were 23% and 7%, respectively. Haematologic toxicity was the most limiting factor. One patient died from treatment toxicity. Local control rate at one year was 74%. Three-year actuarial survival rate was 27%. Distant metastasis was the main cause of treatment failure. Swallowing score was good for 75% of the patients. Stage, performance status and weight loss were prognostic factors. CONCLUSION: This regimen with high dose RT, HDR brachytherapy and concomitant CT is feasible; however, a high level of haematologic toxicity was observed with the CDDP, 5FU and MMC regimen. Despite a poor compliance with CT, treatment results are very encouraging for patients with locally advanced disease.

Adult↗

Sludge in fetal gallbladder: natural history and neonatal outcome.

Normal and pathological conditions of the fetal gallbladder have been a subject of recent investigation by ultrasonographers. Fetal gallstones are the most common abnormal finding and appear as echogenic foci within the gallbladder. We report a series of five fetuses in whom the gallbladders were filled with sludge which appeared as a pear shape echogenic structure. In the majority of cases, gallbladder sludge mimicked intrahepatic calcification or echogenic bowel. Serial ultrasound examinations of these fetuses revealed good interval growth. The gallbladders remained echogenic and were normal in size in three cases and were moderately enlarged in two. All neonates were born in normal condition with no identifiable malformations. Follow-up was obtained in four infants using abdominal ultrasound. A normal appearing sludge free gallbladder was seen in three neonates at 6 weeks of life and in four infants at 12 weeks. Accurate diagnosis of gallbladder sludge will spare the patient unnecessary work-up and anxiety. The natural history of gallbladder sludge in the fetus is benign in nature and is similar to that of fetal gallstones.

Calcinosis↗

Characterization of a de novo t(Y;9) (q11.2;q22) by FISH technique.

A new case with a de novo translocation involving the long arms of chromosomes Y and 9 i.e. 46, X, t(Y;9) (q11.2;q22) was noted in a phenotypically normal male as revealed by GTG technique and subsequently confirmed using dual color whole chromosome painting probes. Since the Yq11.2 region was involved in the translocation the fecundity status of the individual has been questioned. Previous cases with (Y;autosomal) translocations have produced males with azoospermia, a variety of male gamete deformities and idiopathic sterility. The azoospermic factor (AZF) on the distal Yq11 band, which apparently controls spermatogenesis, may have been adversely affected due to a microdeletion, rearrangement or complete loss as a result of the translocation mechanism. Testicular histological and fertility tests of the proband at a postpubescent age will reveal the status. The sex determining region (SRY) on the Yp, which has been equated with the testis determining factor (TDF), is believed to be intact. Dual color whole chromosome painting probes, which served as an important adjunct to GTG banding, increased the degree of certainty for the characterization of the involved translocation. A concise review of balanced (Y ; autosome) translocation cases are annotated here.

Chromosomes, Human, Pair 9↗

Isolation and localization of transcribed sequences on human chromosome 22.

Recently, we reported the generation of a heteronuclear (hn) cDNA library from a human x rodent somatic cell hybrid retaining human chromosome 22. Here, we report the characterization and localization of 12 cDNA derived clones from this library. Human-specific cDNA sequences have been selectively amplified by inter-Alu PCR. To exclude Alu transcripts, only clones with inserts larger than 500 bp were analyzed. Ten of the 12 clones were localized by PCR on chromosome 22, with four clones mapping on additional chromosomes. One PCR-localized clone and two additional clones were mapped on chromosome 22 by in situ hybridization. Transcripts in human cells were identified for seven of the eight clones analyzed by RT-PCR. None of the clones showed significant sequence similarities within the GenBank and EMBL databases, indicating that these clones represent previously unknown genes. This is the first report on the isolation of chromosome 22-specific transcripts from a human x rodent somatic cell hybrid.

Animals↗

Strategy for chromosomal assignment of expressed sequences derived from heteronuclear RNA.

The chromosomal localization of transcribed sequences/genes is one of the objectives of the human genome project. Here, we describe a novel strategy for fast and dependable chromosomal assignment of expressed sequences that contain Alu sequences. Alu-PCR was performed on cDNA that was derived from heteronuclear (hn) RNA. hn-cDNA libraries are utilized for the identification of genes from extended human chromosomal regions or entire chromosomes. For chromosomal assignment, Alu-PCR products larger than 500 bp were hybridized against genomic DNA of somatic cell hybrids that was also amplified by Alu-PCR. Hybridization signals obtained within 2-3 h of exposure allow localization of cDNA-derived Alu-PCR products to single chromosomes. This technique is particularly useful for the analysis of cDNA libraries derived from hn-RNA. Using hn-cDNA clones from different chromosomes, we demonstrate the accuracy and reliability of the mapping strategy.

Animals↗

Generation of a chromosome-22-specific c-DNA library as confirmed by FISH analysis.

We have recently developed a strategy for the rapid enrichment of c-DNA fragments from selected human chromosomes. Heteronuclear RNA (hn-RNA) is isolated from a somatic cell hybrid that retains a single human chromosome in a rodent background. Following c-DNA synthesis, human sequences are selectively amplified by the Alu polymerase chain reaction (Alu-PCR). Here we have applied this protocol for the selective isolation of novel c-DNAs encoded by chromosome 22. Fluorescence in situ hybridization has been used to confirm the chromosome-22-specific origin of the c-DNA fragments. Controls show DNAse-free RNase-treated hn-RNA results in no c-DNAs or Alu-PCR products. As demonstrated by competitive in situ suppression hybridization (CISS), the majority of the Alu-PCR products from hybrid GM 10027 are located on chromosome 22. Without competition, hybridization signals have also been identified on other human chromosomes. These unspecific hybridization signals result from Alu sequences and can successfully be reduced by competition with cot 1 DNA. This is the first report of the use of CISS for the localization of chromosome-specific c-DNAs.

Animals↗

Identification of chromosome-specific sequence-tagged sites by Alu-PCR.

Recently, methods have been developed for the isolation of expressed sequences from particular human chromosomes. Using Alu consensus sequences as primers, cDNA synthesis has been initiated from interspecies hybrid cell lines that contain single human chromosomes. Alu consensus sequences have also been utilized to amplify human genomic sequences via polymerase chain reaction (PCR). Here, we describe the use of Alu-PCR to isolate expressed sequences from human chromosomes selectively. Heteronuclear (hn) RNA is transcribed into cDNA by using poly-(dT)15 primer sequences. Subsequently, human specific cDNA sequences are amplified by Alu-PCR and cloned into pBluescript. To verify the chromosomal assignment, cloned PCR products are sequenced, converted into STS markers, and tested on a different somatic hybrid that contains human chromosome 22. The method provides a fast, reliable way to identify expressed sequence tagged sites from selected human chromosomes.

Animals↗

ors12, a mammalian autonomously replicating DNA sequence, associates with the nuclear matrix in a cell cycle-dependent manner.

Origin enriched sequence ors8 and ors12, have been isolated previously by extrusion of nascent CV-1 cell DNA from replication bubbles at the onset of S-phase. Both have been shown to direct autonomous DNA replication in vivo and in vitro. Here, we have examined the association of genomic ors8 and ors12 with the nuclear matrix in asynchronous and synchronized CV-1 cells. In asynchronously growing cells, ors8 was found to be randomly distributed, while ors12 was found to be enriched on the nuclear matrix. Using an in vitro binding assay, we determined that ors12 contains two attachment sites, each located in AT-rich domains. Surprisingly, in early and mid-S-phase cells, ors12 homologous sequences were recovered mainly from the DNA loops, while in late-S the majority had shifted to positions on the nuclear matrix. In contrast, the distribution of ors8 over the matrix and loop DNA fractions did not change during the cell cycle. By bromodeoxyuridine substitution of replicating DNA, followed by immunoprecipitation with anti-bromodeoxyuridine antibodies and PCR amplification, we demonstrated that ors12 replicates almost exclusively on the matrix in early and mid-S-phase; replicating ors8 was also found to be enriched on the matrix in early S-phase. Chase experiments showed that the ors12 sequences labelled with bromodeoxyuridine in the first 2 hours of S-phase remain attached to the nuclear matrix, resulting in an accumulation of ors12 on the nuclear matrix at the end of the S period.

Animals↗

Gene amplification and expression of the neu (c-erbB-2) sequence in human mammary carcinoma.

Alterations in the structure and expression of the neu oncogene were investigated in 15 human mammary tumors. In 7 of the samples (46%), amplification by the factor up to 14 was detected, some samples displaying an additional EcoRI restriction fragment at 3.4 kb. In tumor tissue with amplified neu sequences from which intact RNA was available, enhanced expression was noted. Correlation of the molecular data to clinical parameters indicated a correlation of the neu oncogene amplification to tumor grading and thus poor prognosis.

Breast Neoplasms↗