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Biomedical subjects

C Herman

Publications and source records attributed to C Herman.

At least 19 recordsLinked to original sources
PubMed2006

Occupational exposure to organic solvent mixtures during pregnancy and the risk of non-syndromic oral clefts.

OBJECTIVES: To examine the association between maternal occupational exposure to mixtures of organic solvents during pregnancy and the risk of non-syndromic oral clefts. METHODS: A case-control study (164 cleft lip with/without cleft palate (CL/P), 76 cleft palate (CP), 236 controls) was conducted in France to investigate the role of maternal occupational exposure to organic solvents at the beginning of pregnancy in the risk of non-syndromic oral clefts. An expert chemist, guided by a detailed description of the women's occupational tasks, assessed exposure for each. Analysis of the findings used logistic regression. RESULTS: In the control group, 39% of the women who reported working during pregnancy were exposed to at least one type of organic solvent. The risk of oral clefts was associated with oxygenated (for CL/P: OR = 1.8, 95% CI 1.1 to 2.9; and for CP, OR = 1.4, 95% CI 0.7 to 2.7), chlorinated (OR = 9.4, 95% CI 2.5 to 35.3; OR = 3.8, 95% CI 0.7 to 20.7), and petroleum (OR = 3.6, 95% CI 1.5 to 8.8; OR = 1.2, 95% CI 0.3 to 4.9) solvents. The risk of oral clefts increased linearly with level of exposure within the three subgroups of oxygenated solvents we considered (aliphatic alcohols, glycol ethers, and other oxygenated solvents, including esters, ketones, and aliphatic aldehydes). CONCLUSIONS: Results suggest that maternal occupational exposure to organic solvents during pregnancy may play a role in the aetiology of oral clefts. The limited number of subjects and the problem of multiple exposures require that these results be interpreted cautiously.

Adult↗
PubMed2005

[Periconceptional folates and the prevention of orofacial clefts: role of dietary intakes in France].

BACKGROUND: Orofacial clefts are among the most frequent congenital malformations at birth with a prevalence of 1 in 700 births in Europe. The implication of environmental factors in their etiology has been demonstrated. The role of folic acid, or folates, in the prevention of orofacial clefts is still debated although its efficacy has been demonstrated for the prevention of neural tube defects. METHODS: A case-control study was conducted in 7 hospitals in 4 centers in France. Cases (N=240) were children with non-syndromic orofacial cleft referred to one of the study hospitals for initial surgical repair in 1998 and 1999. Controls (N=236) matched for gender, geographic origin, and age were chosen in paediatric departments of the same hospitals. Usual dietary intake of folates was estimated using a food frequency questionnaire submitted to the mother at hospital. During the same interview, data on sociodemographic characteristics, medical and obstetrical history, tobacco and alcohol consumption, and vitamin supplements, were obtained. Odds ratios associated with quintiles of dietary intake of folates were estimated using logistic regression adjusting for known confounders. RESULTS: A significant dose-response relationship between the risk of orofacial clefts and a decrease in the intake of folates from diet was found, stronger for cleft palate without cleft lip. Only few women (<1%) declared having taken vitamin supplements containing folic acid when planning their pregnancy. CONCLUSION: Our study further suggests that folates are useful for the prevention of orofacial clefts during the periconceptual period. In our study, the estimated average daily intake of folates (270 microg/day) was below French national recommendations for the prevention of neural tube defects (400 microg/day). Since those insufficient folate intakes during the periconceptual period are not presently met by vitamin supplementation, the solution may come from the food fortification program proposed and implemented by the National Agency for Food Safety (AFSSA).

Adult↗
PubMed2005

Factor VIII inhibitor associated with peginterferon.

We present a case of a 53-year-old black male who developed a factor VIII inhibitor during his treatment for hepatitis C virus infection with peginterferon. The development of inhibitors against factor VIII during peginterferon therapy has been rarely reported. We have reviewed the current literature and the following case presentation provides the first demonstration, to our knowledge, in which chronic exposure to peginterferon is associated with an acquired factor VIII inhibitor.

Antibodies, Monoclonal↗
PubMed2002

A randomised, controlled trial of cognitive and psychomotor recovery from midazolam sedation following reversal with oral flumazenil.

Flumazenil is traditionally administered intravenously to reverse the adverse effects of over sedation with benzodiazepines. The aim of this study was to test postoperative cognitive and psychomotor recovery from midazolam conscious sedation, following reversal with orally administered flumazenil. It was hypothesised that when administered by the oral route, flumazenil may enhance recovery over a prolonged period, thus increasing safety. Eighteen patients requiring intravenous midazolam sedation for dental treatment completed a randomised, double-blind, crossover trial. Following treatment the patients' sedation was reversed using either flumazenil or saline (as placebo), administered orally, on alternate appointments. Assessment of mood and cognitive function were undertaken using ClinPhone.cdr(R), a highly sensitive and specific computerised battery of cognitive tests administered by telephone prior to sedation and every hour for seven hours post reversal. Results indicate that within 20 min of administration, oral flumazenil is capable of partially reversing some cognitive and psychomotor impairments but the attentional and stimulus discrimination effects of midazolam sedation still remain.

Administration, Oral↗
PubMed2002

Validation of a telephone cognitive assessment test battery for use in chronic fatigue syndrome.

We compared a computerized version of the Cognitive Drug Research (CDR) cognitive assessment test battery and a completely automated telephone version of the same battery. These assessed aspects of attention, working memory and long-term memory. Both methods were used to assess the cognitive performance of a cohort of 30 people with confirmed chronic fatigue syndrome (CFS) and a group of 30 healthy controls matched for age and education. The CFS group had significantly slower reaction times on all four cognitive measures on both the computerized and telephone tests. The mood data followed similar patterns inthe computer and telephone assessments. The results from both forms of the test battery confirmed the pattern and severity of cognitive impairment in CFS. Furthermore, the two methods of testing were similarly sensitive in detecting cognitive deficits. The incapacitating nature of CFS may cause problems for researchers if the restrictions to mobility affect the representativeness of the study group. The findings of the present study support the use of a fully automated telephone cognitive testing system for detecting deficits in CFS.

Attention↗
PubMed2001

F-18 FDG uptake in a patient with psoriatic arthritis: imaging correlation with patient symptoms.

The authors describe a patient with psoriatic arthritis in whom an increased level of F-18 fluorodeoxyglucose (F-18 FDG) uptake was seen in the joints of the hands. The areas of increased activity correlated well with the regions of symptoms reported by the patient. This case illustrates the potential use of F-18 FDG positron emission tomography to quantitatively assess the degree of arthritis activity.

Antineoplastic Agents↗
PubMed2001

Case study: how to apply data mining techniques in a healthcare data warehouse.

Healthcare provider organizations are faced with a rising number of financial pressures. Both administrators and physicians need help analyzing large numbers of clinical and financial data when making decisions. To assist them, Rush-Presbyterian-St. Luke's Medical Center and Hitachi America, Ltd. (HAL), Inc., have partnered to build an enterprise data warehouse and perform a series of case study analyses. This article focuses on one analysis, which was performed by a team of physicians and computer science researchers, using a commercially available on-line analytical processing (OLAP) tool in conjunction with proprietary data mining techniques developed by HAL researchers. The initial objective of the analysis was to discover how to use data mining techniques to make business decisions that can influence cost, revenue, and operational efficiency while maintaining a high level of care. Another objective was to understand how to apply these techniques appropriately and to find a repeatable method for analyzing data and finding business insights. The process used to identify opportunities and effect changes is described.

Chicago↗
PubMed2000

Changes in public health nurses' knowledge and perception of counseling and clinical skills for breast and cervical cancer control.

This study discusses the findings from two surveys of 459 nurses working in public health about their knowledge and perception of counseling and clinical skills related to breast and cervical cancer control. The first survey was conducted in 1993 before professional education efforts with the Breast and Cervical Cancer Control Program (BCCCP) began in North Carolina. The second survey was carried out in 1996. The results show a significant increase from 1993 to 1996 in recognition of increasing age, nulliparity, late childbearing, and family history as risk factors for breast cancer, and for smoking and early age at first sexual intercourse as risk factors for cervical cancer. Nurses' skills were more likely to be rated as excellent or very good in 1996 as compared with ratings in 1993 for educating women about mammography, performing a clinical breast examination, teaching breast self-examination by demonstration, performing a Papanicolaou (Pap) smear and bimanual examination, and counseling women about abnormal Pap tests. Nurses who took a BCCCP-sponsored adult physical assessment course were more likely to know correct risk factors for breast and cervical cancer, and to show improvement in teaching breast self-examination, performing a Pap smear, and counseling women about abnormal Pap tests.

Adult↗
PubMed1999

The mitochondrial permeability transition: the brain's point of view.

The mitochondrial permeability transition (mPT) has been implicated in both central nervous system ischaemia/reperfusion injury and excitotoxic neuronal death. To characterize the mPT of brain mitochondria, fluorescent mitochondrial dyes were applied to cultured neurons and astrocytes and isolated brain mitochondria were prepared. In astrocytes, mPT induction was observed as calcium-induced mitochondrial swelling following permeabilization by digitonin or introduction of a calcium ionophore. In hippocampal neurons, mPT induction was observed upon introduction of calcium and ionophore or application of toxic doses of glutamate. In isolated brain mitochondria, calcium dose-dependently produced calcium accumulation and mitochondrial swelling that was prevented by pretreatment with ADP or cyclosporin A. Additionally, when mitochondrial substrates were limited, calcium dose-dependently produced mitochondrial depolarization without swelling or calcium accumulation that was reversed by ADP, cyclosporin A or Ruthenium Red. The degree of mitochondrial depolarization was modulated by free fatty acids, magnesium, calcium concentration and protonophore Repolarization of mitochondria and closure of this low-conductance manifestation of the mPT pore by cyclosporin A was modulated by the degree of depolarization.

Animals↗
PubMed1998

Degradation of carboxy-terminal-tagged cytoplasmic proteins by the Escherichia coli protease HflB (FtsH).

Proteins with short nonpolar carboxyl termini are unstable in Escherichia coli. This proteolytic pathway is used to dispose of polypeptides synthesized from truncated mRNA molecules. Such proteins are tagged with an 11-amino-acid nonpolar destabilizing tail via a mechanism involving the 10Sa (SsrA) stable RNA and then degraded. We show here that the ATP-dependent zinc protease HflB (FtsH) is involved in the degradation of four unstable derivatives of the amino-terminal domain of the lambdacI repressor: three with nonpolar pentapeptide tails (cI104, cI105, cI108) and one with the SsrA tag (cI-SsrA). cI105 and cI-SsrA are also degraded by the ClpP-dependent proteases. Loss of ClpP can be compensated for by overproducing HflB. In an in vitro system, cI108 and cI-SsrA are degraded by HflB in an energy-dependent reaction, indicating that HflB itself recognizes the carboxyl terminus. These results establish a tail-specific pathway for removing abnormal cytoplasmic proteins via the HflB and Clp proteases.

ATP-Dependent Proteases↗
PubMed1998

Mutation of proline 211 reduces shedding of the human p75 TNF receptor.

We have identified a residue necessary for the cleavage of human p75 TNF-R from the cell surface by deletion and mutagenesis analysis of the membrane-proximal domain between amino acids 147 and 221. Deletion analysis of this area showed that residues between amino acids 207 and 216 are required for shedding. Site-directed mutagenesis of proline 211 to glycine reduced PMA-induced shedding of human p75 TNF-R from COS-7 or Raw 264.7 cells. Mutation of glycine 210 to aspartic acid did not affect receptor shedding. Mutation of serine 212 to leucine did not affect the PMA-induced shedding from the surface of COS-7 cells, but reduced the efficiency of shedding from the surface of Raw 264.7 macrophages by PMA or LPS. Deletion of putative elastase cleavage sites at amino acids 151 to 153, 162 to 163, and 177 to 178 (also a putative metalloprotease site similar to the cleavage site of TNF-alpha) or mutation of a serine-threonine-serine motif resembling a similar motif at the site of L-selectin cleavage at amino acids 202 to 204 did not reduce shedding of p75 TNF-R after treatment of cells with PMA. This work shows that a single amino acid mutation at proline 211 of human p75 TNF-R can prevent shedding from the cell surface, and that deletion of other previously proposed putative cleavage sites of the human p75 TNF-R does not prevent its shedding.

Amino Acid Sequence↗
PubMed1998

Characteristics of rectal carcinomas that predict the presence of lymph node metastases: implications for patient selection for local therapy.

BACKGROUND AND OBJECTIVES: It has been estimated that approximately 5% of middle and low rectal adenocarcinomas are amenable to local therapy. However, these treatment modalities are limited by their failure to identify and treat regional nodal metastases. METHODS: This study was undertaken to evaluate the role of tumor size, depth of penetration into the rectal wall, degree of histologic differentiation, DNA ploidy status, and their combination on the presence or absence of metastases in perirectal lymph nodes. Logistic regression was used to quantitatively predict the probability of positive lymph nodes. RESULTS: Tumor size did not correlate with the presence of nodal involvement; however, worsening degree of differentiation, increasing depth of wall penetration and aneuploidy did statistically correlate with the presence of nodal metastases. For any combination of tumor traits, aneuploidy markedly increased the probability of positive lymph nodes over that observed with diploid tumors. CONCLUSIONS: The combination of degree of differentiation, depth of penetration, and ploidy status may be used to identify patients whose tumors may be adequately treated with local measures. For any combination of tumor traits, aneuploidy markedly increased the probability of positive lymph nodes over that observed with diploid tumors.

Adult↗
PubMed1998

Proteolysis and chaperones: the destruction/reconstruction dilemma.

Cytoplasmic proteases, although necessary for proper cell functioning, must be strictly regulated. In fact, they resemble chaperones, ancient protein folding devices. These molecules recognise exposed hydrophobic regions of unfolded or denatured proteins. For most substances it is not known how the cell chooses between the refolding and proteolytic pathways. In Escherichia coli, however, a carboxy-terminal proteolysis tag and binding site for the chaperone DnaK have recently been identified.

Bacterial Proteins↗
PubMed1998

Gene therapy for rheumatoid arthritis. Theoretical considerations.

Current understanding of the pathogenesis of rheumatoid arthritis has provided evidence that therapeutic benefit can be achieved by using antagonists targeted to the inflammatory cytokines involved, mainly tumour necrosis factor-alpha and interleukin-1. Gene delivery of antagonists, which can inhibit the production or action of these cytokines and other mediators, has been achieved in experimental animal models. This new method of delivery can produce therapeutic effects at lower concentrations and in a local environment, overcoming the adverse effects that often accompany protein therapy. However, several technological and biological restraints preclude the immediate adaptation of this method to human treatment. Based on the experimental evidence, possible target therapeutic genes, cell types and vector systems that could be used are discussed in this article.

Arthritis, Rheumatoid↗
PubMed1997

The HflB protease of Escherichia coli degrades its inhibitor lambda cIII.

The cIII protein of bacteriophage lambda is known to protect two regulatory proteins from degradation by the essential Escherichia coli protease HflB (also known as FtsH), viz., the lambda cII protein and the host heat shock sigma factor sigma32. lambda cIII, itself an unstable protein, is partially stabilized when the HflB concentration is decreased, and its half-life is decreased when HflB is overproduced, strongly suggesting that it is degraded by HflB in vivo. The in vivo degradation of lambda cIII (unlike that of sigma32) does not require the molecular chaperone DnaK. Furthermore, the half-life of lambda cIII is not affected by depletion of the endogenous ATP pool, suggesting that lambda cIII degradation is ATP independent (unlike that of lambda cII and sigma32). The lambda cIII protein, which is predicted to contain a 22-amino-acid amphipathic helix, is associated with the membrane, and nonlethal overproduction of lambda cIII makes cells hypersensitive to the detergent sodium dodecyl sulfate. This could reflect a direct lambda cIII-membrane interaction or an indirect association via the membrane-bound HflB protein, which is known to be involved in the assembly of certain periplasmic and outer membrane proteins.

ATP-Dependent Proteases↗
PubMed1996

Changes in blood cell numbers and formation of eicosanoids during clotting in warm- and cold-acclimated bullfrogs (Rana catesbeiana).

Amphibian blood cells play an important role in eicosanoid synthesis. Formation of eicosanoids during clotting of whole human blood but not frog blood has been reported. Amphibian blood cell numbers are affected by cold exposure; therefore eicosanoid production may reflect these changes. Blood cell changes during warm, and short- and long-term-cold exposure periods were recorded and the formation of leukotriene B4 (LTB4), LTC4, thromboxane (TXB2), and prostaglandin E2 (PGE2) was measured during blood clotting by using radioimmunoassay. Short-term (1 day) cold exposure (5 degrees) did not significantly decrease blood cell number or eicosanoid production during clotting. However, following exposure to cold (5 degrees) for 10 or 30 days, blood cell number and production of LTB4, TXB2, and PGE2 during clotting decreased when compared with warm acclimated controls (22 degrees). LTC4 levels during blood clotting decreased significantly only after 30 days of cold exposure. The results demonstrate that eicosanoid synthesis can be correlated with blood cell number in warm- and cold-exposed bullfrogs.

Acclimatization↗
PubMed1996

Bisallylic hydroxylation and epoxidation of polyunsaturated fatty acids by cytochrome P450.

Polyunsaturated fatty acids can be oxygenated by cytochrome P450 to hydroxy and epoxy fatty acids. Two major classes of hydroxy fatty acids are formed by hydroxylation of the omega-side chain and by hydroxylation of bisallylic methylene carbons. Bisallylic cytochrome P450-hydroxylases transform linoleic acid to 11-hydroxylinoleic acid, arachidonic acid to 13-hydroxyeicosa-5Z,8Z,11Z,14Z-tetraenoic acid, 10-hydroxyeicosa-5Z,8Z,11Z,14Z-tetraenoic acid and 7-hydroxyeicosa-5Z,8Z,11Z,14Z-tetraenoic acid and eicosapentaenoic acid to 16-hydroxyeicosa-5Z,8Z,11Z,14Z,17Z-pent aenoic acid, 13-hydroxyeicosa-5Z,8Z,11Z,14Z,17Z-pent aenoic acid and 10-hydroxyeicosa-5Z,8Z,11Z,14Z,17Z-pent aenoic acid as major metabolites. The bisallylic hydroxy fatty acids are chemically unstable and decompose rapidly to cis-trans conjugated hydroxy fatty acids during acidic extractive isolation. Bisallylic hydroxylase activity appears to be augmented in microsomes induced by the synthetic glucocorticoid dexamethasone and by some other agents, but the P450 gene families of these hydroxylases have yet to be determined. The fatty acid epoxides, which are formed by cytochrome P450, are chemically stable, but are hydrolyzed to diols by soluble epoxide hydrolases. Epoxidation of polyunsaturated fatty acids is a prominent pathway of metabolism in the liver and the renal cortex and epoxy-genase activity appears to be under homeostatic control in the kidney. Many arachidonate epoxygenases have been identified belonging to the CYP2C gene subfamily. Epoxygenases have also been found in the central nervous system, endocrine organs, the heart and endothelial cells. Epoxides of arachidonic acid have been found to exert pharmacological effects on many cells.

Animals↗