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Biomedical subjects

C Albert

Publications and source records attributed to C Albert.

At least 37 records · Page 2Linked to original sources
PubMed1998

Ovarian follicular dynamics: from basic science to clinical practice.

The management of low responders (LR) to ovarian stimulation in cycles of assisted reproduction (AR) is a difficult challenge. Aging of the ovary and LR are coincidental in many situations, but LR is also present in young patients undergoing AR. In fact, today it is a recognized cause of infertility. When the aged ovary is considered, there is evidence that the functioning of the granulosa cells as well as the quality of the oocytes and resulting embryos are affected. Similarly, in young LR, the production of inhibin is affected. However, there is no evidence that the quality of the oocyte and/or the resulting embryo is affected. In this study, we have retrospectively analyzed our files and observed that the quality of the oocytes and embryos was similar between younger and older LR and normal responders (NR). Studies using color Doppler vaginal ultrasound have shown that the pulsatility index (PI) and the resistance index (RI) were increased in LR as compared with NR, suggesting that there was some degree of vascular resistance to flow. Treatment of LR is also a difficult challenge. Ovum donation is a successful treatment for LR, since cumulative birth rates are > 85% with four attempts of embryo transfer. The future may be promising for LR once new technologies are introduced into clinical practice. The use of recombinant gonadotropins and genetically engineered human gonadotropin derivatives may be of considerable help for LR. Similarly, non-gonadotropin hormones, such as cytokines or growth factors, may be shown to play a role in the stimulation of the ovary in the near future, and may therefore open new frontiers for treatment of LR.

Aging↗
PubMed1997

Biological variability in the structures of diphosphoinositol polyphosphates in Dictyostelium discoideum and mammalian cells.

Previous structural analyses of diphosphoinositol polyphosphates in biological systems have relied largely on NMR analysis. For example, in Dictyostelium discoideum, diphosphoinositol pentakisphosphate was determined by NMR to be 4- and/or 6-PPInsP5, and the bisdiphosphoinositol tetrakisphosphate was found to be 4, 5-bisPPInsP4 and/or 5,6-bisPPInsP4 [Laussmann, Eujen, Weisshuhn, Thiel and Vogel (1996) Biochem. J. 315, 715-720]. We now describe three recent technical developments to aid the analysis of these compounds, not just in Dictyostelium, but also in a wider range of biological systems: (i) improved resolution and sensitivity of detection of PPInsP5 isomers by microbore metal-dye-detection HPLC; (ii) the use of the enantiomerically specific properties of a rat hepatic diphosphatase; (iii) chemical synthesis of enantiomerically pure reference standards of all six possible PPInsP5 isomers. Thus we now demonstrate that the major PPInsP5 isomer in Dictyostelium is 6-PPInsP5. Similar findings obtained using the same synthetic standards have been published [Laussmann, Reddy, Reddy, Falck and Vogel (1997) Biochem. J. 322, 31-33]. In addition, we show that 10-25% of the Dictyostelium PPInsP5 pool is comprised of 5-PPInsP5. The biological significance of this new observation was reinforced by our demonstration that 5-PPInsP5 is the predominant PPInsP5 isomer in four different mammalian cell lines (FTC human thyroid cancer cells, Swiss 3T3 fibroblasts, Jurkat T-cells and Chinese hamster ovary cells). The fact that the cellular spectrum of diphosphoinositol polyphosphates varies across phylogenetic boundaries underscores the value of our technological developments for future determinations of the structures of this class of compounds in other systems.

3T3 Cells↗
PubMed1996

Expression and regulation of the lipoprotein lipase gene in human adrenal cortex.

Lipoprotein lipase (LPL), an enzyme which hydrolyzes triglycerides and participates in the catabolism of remnant lipoproteins, plays a crucial role in energy and lipid metabolism. The goal of this study was to analyze the expression and regulation of the LPL gene in human adrenals. Reverse transcriptase-polymerase chain reaction amplification and sequence analysis demonstrated the presence of LPL mRNA in fetal and adult human adrenal cortex. Furthermore, the human adrenocortical carcinoma cell line, NCI-H295, expresses LPL mRNA and protein, which is localized to the outer cellular membrane as demonstrated by immunofluorescence confocal microscopy and can be released in the medium by heparin addition. To asses whether the LPL gene is regulated by agents regulating adrenal steroidogenesis, NCI-H295 cells were treated with activators of second messenger systems. Whereas the calcium-ionophore A23187 did not affect LPL gene expression, treatment with phorbol 12-myristate 13-acetate decreased LPL mRNA levels in a time- and dose-dependent manner. This decrease after phorbol 12-myristate 13-acetate was associated with diminished heparin-releasable LPL mass and activity in the culture medium. Addition of the cAMP analog 8-Br-cAMP to NCI-H295 cells resulted in a rapid, but transient dose-dependent induction of LPL mRNA. Treatment with the protein synthesis inhibitor cycloheximide gradually induced, whereas simultaneous addition of cAMP and cycloheximide superinduced LPL mRNA levels. Nuclear run-on analysis indicated that the effects of cAMP and cycloheximide occurred at the transcriptional and post-transcriptional level, respectively. Transient co-transfection assays demonstrated that the first 230 base pairs of the proximal LPL promoter contain a cAMP-responsive element activated by protein kinase A and transcription factors belonging to the CREB/CREM family. These data indicate that LPL is expressed in human adrenal cortex and regulated in NCI-H295 adrenocortical carcinoma cells by activators of the protein kinase A and protein kinase C second messenger pathways in a manner comparable to P450scc, which catalyzes the first step in adrenal steroidogenesis. These observations suggest a role for LPL in adrenal energy and/or lipid metabolism and possibly in steroidogenesis.

8-Bromo Cyclic Adenosine Monophosphate↗
PubMed1996

[Multicystic peritoneal mesothelioma].

We report on a 31-year-old man with a 29 x 15 x 15 cm large abdominal tumor who came to surgery under suspicion of echinococcus cyst of the liver. Histologically, the neoplasm could identified as multicystic peritoneal mesothelioma (synonyma: benign cystic mesothelioma). Additionally some cysts were located in the greater omentum and mesocolon. In contrast to our case the benign cystic mesotheliomas most commonly occur in young women, localized in the pelvis and abdomen and often complicated by postoperative local recurrence. We performed a resection of the right hemicolon and the omentum. Postoperatively no further therapy was necessary because of the benign appearance of the lesion. Close follow-up is required in these patients due to the disposition for recurrences.

Adult↗
PubMed1995

Ethane exhalation and vitamin E/ubiquinol status as markers of lipid peroxidation in ferrocene iron-loaded rats.

Organ damage caused by iron overload has been mostly attributed to iron-induced peroxidation of membrane lipids. Using the ferrocene iron-loaded rat model, we studied ethane exhalation as a direct marker of in vivo lipid peroxidation, as well as concentrations of alpha-tocopherol and ubiquinol 9/10 in liver and plasma as indirect markers of this process. The feeding of a diet enriched with 0.5% TMH-ferrocene up to 31 weeks resulted in a large increase in liver iron concentration to about 25 mg/g wet weight (w wt). At lower, predominantly hepatocellular liver siderosis, the breath ethane exhalation was dependent on dietary vitamin E (VitE) supplements (onset of ethane exhalation at liver-Fe > 2 mg/g w wt on vitE-restricted diet; > 5 mg Fe per gram on VitE-replete diet). At severe liver siderosis, breath ethane exhalation reached a maximum of approximately 8 nmol/kg/hr independent of VitE supplementation. Plasma as well as hepatic alpha-tocopherol decreased with progressive iron loading. In addition, a significant depletion in hepatic ubiquinol 9 and 10 was noted.

Animals↗
PubMed1993

Reduction of short-term radiation lethality by biological response modifiers given alone or in association with other chemical protectors.

The advantages gained by a combined treatment of different chemical protectors on short-term lethality of X-irradiated adult male mice have been studied. The following compounds were given alone or in a mixture of two or three compounds: 16,16-dimethyl PGE2 (PGE2), cysteine (Cys), glucan, glutathione (GSH), 5-hydroxytryptamine (5-HT), mercaptoproprionylglycine (MPG), or WR-2721. The survival of mice treated before X irradiation with the optimal dose of each radioprotector given separately shows that WR-2721 and 5-HT yield the best protection with dose reduction factors (DRFs) of 2.2 and 1.7, respectively. Cysteine, glucan, PGE2, MPG, and GSH, with DRFs of 1.4, 1.4, 1.2, 1.1, and 1.1, respectively, are less efficient radioprotectors. When PGE2 was combined with a low dose of WR-2721 (200 mg/kg), the protection increased in a synergistic way. The increase in protection offered by a combination of PGE2 with Cys, glucan, GSH, or 5-HT is less marked and the effect obtained is only additive. A synergistic action is also obtained with a combination of WR-2721 (200 mg/kg) and 5-HT (8 mg/kg) (DRF 2.7).

16,16-Dimethylprostaglandin E2↗
PubMed1992

[Chronic kidney failure in the elderly].

Ageing does not spare the kidneys but, remarkably, renal impairment is virtually asymptomatic as homaeostasis remains ensured. Nevertheless, in routine practice physicians must take into account the "physiological" renal insufficiency of the elderly. In old people with chronic renal impairment the diagnostic and therapeutic approaches are special, owing to the age-related risks attached to both paraclinical examinations and treatments. Yet in certain subjects treatment can be remarkably effective and prevent the progression to terminal uraemia, and this justifies the detection and exploration of renal insufficiency in elderly patients. In the last few years, iterative dialysis programmes have been made available to third or even fourth age patients who had reached the so-called end-stage renal failure. The results are encouraging, but there are still purely medical questions concerning the measures to be taken in priority and the numerous organization problems to be solved for optimal management of these patients.

Aged↗
PubMed1990

[Is peritoneal dialysis adequate in the treatment of terminal uremia in aged patients].

In Europe and in the United States, the elderly comprise an increasing segment of the end-stage renal disease population on chronic dialysis. Based on our own experience (84 patients over 75 years treated by PD between 1983 and 1990), the aim of the study was to analyze the advantages and disadvantages of peritoneal dialysis (PD). There are many benefits of PD for elderly patients including less hemodynamic stress than hemodialysis, no need for a vascular access, increased mobility and sense of control over illness, maintenance of residual diuresis. Increasing experience in geriatric PD leads to a better control of problems which may affect the outcome of PD (inability to perform self-dialysis, nutritional abnormalities, peritonitis, bowel dysfunction). PD appears to be an acceptable form of renal replacement therapy in the elderly.

Aged↗
PubMed1987

The rorschach assessment of borderline defenses: a concurrent validity study.

This study assesses the concurrent validity of two Rorschach defense scales designed to identify borderline defensive structure. A Rorschach scale designed by Cooper and his colleagues was systematically compared to a defense scale constructed by Lerner and Lerner. Despite considerable overlap on a conceptual and operational level, the scales are based on divergent theoretical models (developmental arrest and fixation) and Rorschach units of analysis (all responses and human responses). Our results are based on the capacity of each scale to discriminate between independently diagnosed samples (neurotic, outpatient borderline, inpatient borderline, schizophrenic) and the relative discriminatory power of particular defenses within each scale to differentiate between groups.

Adolescent↗
PubMed1983

Progressive pseudorheumatoid arthritis of childhood (PPAC). A hereditary disorder simulating rheumatoid arthritis.

Five patients are described with a hereditary arthropathy affecting major and minor joints. The main features of this progressive connective tissue disorder are restricted joint mobility, osseous swelling of the interphalangeal and other joints, and platyspondyly. The condition is commonly misdiagnosed as "chronic juvenile polyarthritis with Scheuermann disease". It differs from the rheumatoid-factor-negative polyarticular form of rheumatoid arthritis and other rheumatoid spondylarthropathies by the absence of arthritic and other inflammatory changes, radiographically by the absence of destructive and the presence of dysplastic bone changes. The disorder does not seem to respond to the usual forms of antirheumatoid treatment. Histological studies showed a peculiar, nest-like clustering of chondrocytes in the resting and growth cartilage suggesting that pathogenetically this is a primary disorder of the articular cartilage.

Adolescent↗
PubMed1983

Ultrastructural alterations in peripheral nerve trunks of rats subchronically treated with chlorphentermine or perhexiline.

The present study deals with the effects of two lipidosis-inducing drugs (chlorphentermine and perhexiline) upon the ultrastructure of large nerve trunks (sciatic and plantar nerves) of adult rats. Subchronic oral administration of high doses of either drug led to comparatively mild lipidosis-like alterations in Schwann cells and in other cell types of both nerve trunks. In addition, plantar nerves, and more rarely sciatic nerves, showed some unspecific lesions such as myelin whorls and ovoids within the outer Schwann cell cytoplasm, intra-axonal accumulations of polymorphous material, and single degenerating fibres. The pathogenetic mechanisms responsible for the non-specific lesions remain to be elucidated. Chlorphentermine was, in all respects, more potent than perhexiline. In general, the drug-induced lesions developing in the fibres of large nerve trunks were less dramatic when compared a) with the severe lipidosis known to occur in neuronal perikarya, and b) with the severe alterations known to develop in preterminal or terminal axon portions of rats kept under similar experimental conditions.

Animals↗