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Biomedical subjects

C Berg

Publications and source records attributed to C Berg.

At least 73 records · Page 4Linked to original sources
PubMed2001

Insulin's effect on synthesis rates of liver proteins. A swine model comparing various precursors of protein synthesis.

Insulin's effect on the synthesis of liver proteins remains to be fully defined. Previous studies using various surrogate measures of amino acyl-tRNA have reported variable results of insulin's effect on liver protein synthesis. We determined the effect of insulin with or without amino acid supplementation on the synthesis rates of liver proteins (tissue, albumin, and fibrinogen) using L-[1-13C]Leu as a tracer in 24 male miniature swine. In addition, we compared the isotopic enrichment of different precursors of liver proteins with that of amino acyl-tRNA using L-[1-13C]Leu and L-[15N]Phe as tracers. Although liver tissue fluid enrichment of [13C]Leu and [15N]Phe and that of plasma [13C]ketoisocaproatic acid (KIC) were very similar to that of tRNA, plasma isotopic enrichment of both Leu and Phe were substantially higher (P < 0.01) and VLDL apolipoprotein-B100 enrichment was lower (P < 0.01) than the respective amino acyl-tRNA enrichment. Plasma KIC enrichment most accurately predicted leucyl-tRNA enrichment, whereas plasma Leu enrichment was best correlated with that of tRNA. Neither insulin alone nor insulin plus amino acid infusion had an effect on liver tissue protein synthesis. In contrast, insulin alone decreased the albumin synthesis rate, and insulin with amino acids maintained the albumin synthesis rate. Insulin with or without amino acids inhibited the fibrinogen synthesis rate. These results, based on synthetic rates using amino acyl-tRNA, were consistent with those obtained using KIC or tissue fluid Leu or Phe as precursor pools. These studies demonstrated that plasma KIC enrichment is a convenient and reliable surrogate measure of leucyl-tRNA in liver. We also concluded that insulin has differential effects on the synthesis rates of liver proteins. Whereas insulin with or without amino acid supplement has no acute effect on the synthesis of liver tissue protein, insulin has a substantial inhibitory effect on fibrinogen synthesis. In contrast, insulin administration along with amino supplement is necessary to maintain albumin synthesis rate.

Amino Acids↗
PubMed2001

Effects of bisphenol A and tetrabromobisphenol A on sex organ development in quail and chicken embryos.

The plastic monomere bisphenol A (BPA) and the flame retardant tetrabromobisphenol A (TBBPA) were examined for estrogen-like developmental effects on the reproductive organs in avian embryos. The synthetic estrogen diethylstilbestrol (DES) was used as a positive control. The test compounds were injected into the yolk of quail and chicken eggs early during incubation and the embryos were examined 2 d before anticipated hatching. At 200 microgram/g egg, BPA induced Müllerian duct (embryonic oviduct) malformation in female quail embryos and feminization of the left testis (ovotestis) in male chicken embryos. The estrogenic potency of BPA compared with DES was species and endpoint specific. Müllerian duct malformation was the most sensitive endpoint in quail embryos, whereas ovotestis formation was the most sensitive response in chicken embryos. Tetrabromobisphenol A caused high embryo mortality at 45 microgram/g egg in both species, but no estrogen-like effects were observed. Bisphenol A caused mortality only in chicken embryos at 67 and 200 microgram/g egg. To our knowledge, this is the first report on estrogen-like or embryolethal effects of BPA and TBBPA in birds.

Animals↗
PubMed2001

Health and welfare in organic poultry production.

This review paper deals with the major health and welfare aspects of organic poultry production. The differences between organic and conventional egg and poultry meat production are discussed, with the main emphasis on housing and management requirements, feed composition and the use of veterinary prophylactic and therapeutic drugs. The effects of the legislation and statutes for organic farming on the health and welfare of the birds are also discussed, especially in relation to the biosecurity problems associated with free-range systems, the occurrence of behavioural disturbances in loose housed flocks and the use of veterinary drugs and vaccinations in general. The results from a questionnaire sent out to all Swedish organic egg producers, where questions about the farmer's perception of the birds' health status were included, are presented at the end of the paper. It is concluded that most of the health and welfare problems seen in conventional poultry systems for loose housed or free ranging birds can also been found on organic poultry farms. It is also concluded that there is a need for information about biosecurity, disease detection and disease prevention on organic poultry farms.

Animal Husbandry↗
PubMed2000

Effect of radiotherapy after breast-conserving treatment in women with breast cancer and germline BRCA1/2 mutations.

PURPOSE: Recent laboratory data suggest a role for BRCA1/2 in the cellular response to DNA damage. There is a paucity of clinical data, however, examining the effect of radiotherapy (RT), which causes double-strand breaks, on breast tissue from BRCA1/2 mutation carriers. Thus the goals of this study were to compare rates of radiation-associated complications, in-breast tumor recurrence, and distant relapse in women with BRCA1/2 mutations treated with breast-conserving therapy (BCT) using RT with rates observed in sporadic disease. PATIENTS AND METHODS: Seventy-one women with a BRCA1/2 mutation and stage I or II breast cancer treated with BCT were matched 1:3 with 213 women with sporadic breast cancer. Conditional logistic regression models were used to compare matched cohorts for rates of complications and recurrence. RESULTS: Tumors from women in the genetic cohort were associated with high histologic (P =.0004) and nuclear (P =.009) grade and negative estrogen (P=.0001) and progesterone (P=.002) receptors compared with tumors from the sporadic cohort. Using Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer toxicity scoring, there were no significant differences in acute or chronic morbidity in skin, subcutaneous tissue, lung, or bone. The 5-year actuarial overall survival, relapse-free survival, and rates of tumor control in the treated breast for the patients in the genetic cohort were 86%, 78%, and 98%, respectively, compared with 91%, 80%, and 96%, respectively, for the sporadic cohort (P = not significant). CONCLUSION: There was no evidence of increased radiation sensitivity or sequelae in breast tissue heterozygous for a BRCA1/2 germline mutation compared with controls, and rates of tumor control in the breast and survival were comparable between BRCA1/2 carriers and controls at 5 years. Although additional follow-up is needed, these data may help in discussing treatment options in the management of early-stage hereditary breast cancer and should provide reassurance regarding the safety of administering RT to carriers of a germline BRCA1/2 mutation.

Adult↗
PubMed2000

Caspase-8/FLICE functions as an executioner caspase in anticancer drug-induced apoptosis.

Caspase-8 plays an essential role in apoptosis triggered by death receptors. Through the cleavage of Bid, a proapoptotic Bcl-2 member, it further activates the mitochondrial cytochrome c/Apaf-1 pathway. Because caspase-8 can be processed also by anticancer drugs independently of death receptors, we investigated its exact role and order in the caspase cascade. We show that in Jurkat cells either deficient for caspase-8 or overexpressing its inhibitor c-FLIP apoptosis mediated by CD95, but not by anticancer drugs was inhibited. In the absence of active caspase-8, anticancer drugs still induced the processing of caspase-9, -3 and Bid, indicating that Bid cleavage does not require caspase-8. Overexpression of Bcl-x(L) prevented the processing of caspase-8 as well as caspase-9, -6 and Bid in response to drugs, but was less effective in CD95-induced apoptosis. Similar responses were observed by overexpression of a dominant-negative caspase-9 mutant. To further determine the order of caspase-8 activation, we employed MCF7 cells lacking caspase-3. In contrast to caspase-9 that was cleaved in these cells, anticancer drugs induced caspase-8 activation only in caspase-3 transfected MCF7 cells. Thus, our data indicate that, unlike its proximal role in receptor signaling, in the mitochondrial pathway caspase-8 rather functions as an amplifying executioner caspase.

Adenocarcinoma↗
PubMed2000

Fast, generic gradient high performance liquid chromatography coupled to fourier transform ion cyclotron resonance mass spectrometry for the accurate mass analysis of mixtures

Fast gradient high performance liquid chromatography (HPLC) has been combined with a commercially available Fourier transform ion cyclotron resonance (FTICR) mass spectrometer for the routine and high performance analysis of mixtures. With this combination we were able to separate and detect, under high mass accuracy conditions, a six-component drug mixture in less than 5 minutes. The fast gradients described are now possible due to the development of mechanically robust, ultra pure silica packing materials, which allow relatively high flow rates (ca. 1 mL/min for a 2 mm diameter column). For the six compounds present in the model mixture, relative mass errors of less than 1 ppm were obtained (based on an external calibration) providing sufficient mass accuracy to make unequivocal assignments of empirical formulae. Preliminary results of fast gradient HPLC/FTICR-MS/MS are also shown for the same six-component mixture. Copyright 2000 John Wiley & Sons, Ltd.

Journal Article↗
PubMed2000

Understanding choice of milk and bread for breakfast among Swedish children aged 11-15 years: an application of the Theory of Planned Behaviour.

The present study examined the influences of attitudes, social norms, perceived control and underlying beliefs on 11 to 15-year-olds' breakfast choices of milk with different fat content and high-fibre bread. All pupils in the 5th, 7th and 9th grades in Mölndal community (N=1730), Sweden, were asked to complete a questionnaire based on the Theory of Planned Behaviour. Two weeks later, they were asked to fill in a 7-day record of food consumed for breakfast. Consumption of milk and high-fibre bread was predicted from intentions, and for milk also by perceived behavioural control. Intentions were influenced by attitudes, perceptions of significant others' preferences, and perceived control. In addition, perception of the parents' consumption (descriptive norm) of the specific food played an important role. Attitudes, norms and perceived control predicted intentions to a similar extent in each age group. Attitudes to the consumption of milk and high fibre bread were influenced by beliefs about their sensory and health aspects. Females and the oldest children had greater knowledge about the healthier alternatives and the oldest children had a tendency to choose healthier options.

Adolescent↗
PubMed2000

Reproductive outcome of 32 patients with primary or secondary infertility and uterine pathology.

We did a retrospective study on 102 patients who had a laparoscopy and a hysteroscopy during investigations for primary or secondary infertility. 32 of the 102 patients had uterine pathology. Seven of them had septate uteri, eight had uterine synechiae, another six had uterine fibroids, four had a bicornuated uterus, while the remaining had either a combination of all or other uterine anomalies. After surgical treatment of these conditions ten women conceived and five pregnancies including one twin pregnancy resulted in term deliveries.

Adult↗
PubMed2000

Fluorescence diagnosis of endometriosis using 5-aminolevulinic acid.

BACKGROUND: The diagnosis of nonpigmented endometrial lesions by simple laparoscopic visualization is difficult and often inaccurate. We therefore sought to establish a new and more accurate method to visualize these nonpigmented peritoneal changes caused by endometriosis. METHODS: A total of 37 patients received 30 mg 5-aminolevulinic acid/kg body weight 10 to 14 hs prior to surgery. Laparoscopy was then performed using a D-light system (Storz, Tuttlingen, Germany). The findings were evaluated first in the white-light mode; the D-light system was then activated, and all areas of fluorescence were documented. Multiple specimens were obtained by biopsy. RESULTS: The sensitivity of the fluorescence diagnosis in detecting endometriosis in nonpigmented areas and normal-looking peritoneum is 100%, with a specificity of 75%. Diagnosis by simple visualization under white illumination has a sensitivity of only 69% and a specificity of 70%. Occult areas of endometriosis were discovered using fluorescence diagnosis. CONCLUSIONS: Our findings suggest that fluorescence diagnosis using 5-aminolevulinic acid is feasible and can improve the diagnosis of endometriosis in nonpigmented and occult endometrial lesions. Fluorescence diagnosis is a promising new tool in the diagnosis of endometriosis.

Aminolevulinic Acid↗
PubMed2000

Subjective evaluation of the therapeutic value of laparoscopic adhesiolysis: a retrospective analysis.

BACKGROUND: Adhesions are believed to be one of the principal causes of chronic pelvic pain. Although there may be some discrepancy between the degree of adhesions and the severity of the symptoms, surgical adhesiolysis is still considered to be useful for the relief of pain. METHODS: A total of 187 patients who underwent laparoscopic adhesiolysis at the Medical University of Ulm, Germany, within a 2-year period were asked to rank their discomfort on a visual pain scale before surgery and up to 1 1/2 years postoperatively. RESULTS: In this retrospective study, we found that nearly one-third of patients suffered from functional irritations that were either ameliorated or completely relieved by laparoscopic adhesiolysis. When other causes of chronic pain (such as endometriosis) are excluded, the results show that most patients benefited from laparoscopic adhesiolysis. CONCLUSIONS: It appears that laparoscopic adhesiolysis is an effective therapeutic measure to relieve chronic pelvic pain. Therefore, adhesiolysis should be performed in all patients with chronic or intermittent pain, and a complete lysis of adhesions should be planned. However, since pelvic pain may have organic or functional causes other than adhesions, complete adhesiolysis in patients with persistent pelvic pain may be of only limited importance.

Adult↗
PubMed2000

Fluorescence diagnosis of endometriosis on the chorioallantoic membrane using 5-aminolaevulinic acid.

The chorioallantoic membrane (CAM) is a useful model for the fluorescence diagnosis of experimentally induced endometriosis. In our experimental setup 75.7% of the histologically examined tissue preparations were viable and only 24.3% showed signs of necrosis on the CAM after various periods of incubation. Best results were obtained when grafting to the CAM was performed between days 7 and 9 and when implants were left on the CAM for 3-5 days (P < 0.05). We were able to demonstrate that 5-aminolaevulinic acid (ALA) is stored selectively in ectopic endometrium. The subsequent fluorescence of the endometrium shows a rapid increase that reaches a peak after 10-14 h which can be clearly differentiated from the weaker fluorescence of grafted normal peritoneum and fimbriae (P < 0.01).

Adult↗
PubMed2000

Mesalazine inhibits activation of transcription factor NF-kappaB in inflamed mucosa of patients with ulcerative colitis.

OBJECTIVES: The salicylate mesalazine is commonly used for the treatment of inflammatory bowel diseases, yet its precise mechanism of action is unknown. Because transcription factor NF-kappaB plays an important role in inflammatory bowel diseases, we investigated the effects of mesalazine therapy on NF-kappaB activation in patients with ulcerative colitis. METHODS: A total of 20 patients with moderately active ulcerative colitis received mesalazine for 8 wk. Biopsies were taken before and after drug administration and analyzed for NF-kappaB activation using an antibody specific for active NF-kappaB. RESULTS: In biopsies of active ulcerative colitis but not in noninflamed mucosa, activation of NF-kappaB was detected predominantly in macrophages. Mesalazine therapy resulted, in a strong abrogation of NF-kappaB activation in situ. CONCLUSIONS: Our results suggest that the therapeutic properties of mesalazine rely at least in part on the inhibition of NF-kappaB activation, resulting in the suppression of proinflammatory gene expression in the inflamed mucosa.

Adult↗
PubMed1999

The avian egg as a test system for endocrine disrupters: effects of diethylstilbestrol and ethynylestradiol on sex organ development.

Many environmental contaminants are known or suspected to interfere with hormonal function in animals. In vivo test methods to detect and characterize chemicals that disrupt the endocrine system are therefore urgently needed. In this study, we assessed the usefulness of abnormalities of the reproductive organs as test endpoints for estrogenic activity of xenobiotics in Japanese quail embryos. Two synthetic estrogens, diethylstilbestrol (DES) and ethynylestradiol (EE2), were injected into the yolks of embryonated eggs. At a dose as low as 2 ng EE2/g egg, all male embryos became feminized, containing ovary-like tissue in the left testis. The extent of feminization of the testes was determined by measuring the relative area of the ovary-like component. Persistent Müllerian ducts (oviducts) in male embryos, and malformations of the Müllerian ducts in females occurred at 2 ng EE2/g egg and higher doses. DES was approximately one-third to one-tenth as potent as EE2. The morphological changes studied were dose-dependent, indicating that they are useful as test endpoints for estrogenic activity. Feminization of the left testis in males proved to be the most sensitive endpoint. We propose the quail egg as a simple in vivo test system for estrogenic compounds.

Androgen-Insensitivity Syndrome↗
PubMed1999

Serious maternal morbidity after childbirth: prolonged hospital stays and readmissions.

OBJECTIVE: To determine the frequency of and risk factors for serious morbidity resulting in a prolonged hospital stay or readmission among women enrolled in Tennessee's Medicaid program who delivered live or dead infants in 1991. METHODS: This retrospective cohort study included 33,251 women of white or black ethnicity. Main outcome measures included childbirth-related medical conditions serious enough to result in death, prolonged delivery hospitalization, or readmission within 60 days of delivery. RESULTS: Among 25,810 women with vaginal (78%) and 7441 (22%) women with cesarean deliveries, 2.6% and 8.9%, respectively, had at least one childbirth-related medical condition requiring prolonged delivery hospitalization or readmission, including infection (1.8% and 7.9%), hypertension-related complications (0.7% and 2.0%), or hemorrhage (0.5% and 2.4%). After controlling for other risk factors, maternal age over 32 years was independently associated with increased rate of serious morbidity among women who had vaginal (relative risk [RR] 1.9, 95% confidence interval [CI] 1.4, 2.7) or cesarean deliveries (RR 1.6, 95% CI 1.1, 2.2). Black women had approximately twice the rate of maternal morbidity with vaginal (RR 1.9, 95% CI 1.5, 2.4) or cesarean deliveries (RR 2.3, 95% CI 1.9, 2.9). Primiparous women who had vaginal or cesarean deliveries had a 60% (RR 1.6, 95% CI 1.3, 2.0) and 70% (RR 1.7, 95% CI 1.4, 2.0), respectively, greater risk of serious maternal morbidity than women with 1-3 prior births. CONCLUSION: Predictors of serious maternal morbidity included age over 32 years, black ethnicity, and primiparity.

Adolescent↗
PubMed1999

Assembly line enzymology by multimodular nonribosomal peptide synthetases: the thioesterase domain of E. coli EntF catalyzes both elongation and cyclolactonization.

BACKGROUND: EntF is a 142 kDa four domain (condensation-adenylation-peptidyl carrier protein-thioesterase) nonribosomal peptide synthetase (NRPS) enzyme that assembles the Escherichia coli N-acyl-serine trilactone siderophore enterobactin from serine, dihydroxybenzoate (DHB) and ATP with three other enzymes (EntB, EntD and EntE). To assess how EntF forms three ester linkages and cyclotrimerizes the covalent acyl enzyme DHB-Ser-S-PCP (peptidyl carrier protein) intermediate, we mutated residues of the proposed catalytic Ser-His-Asp triad of the thioesterase (TE) domain. RESULTS: The Ser1138-->Cys mutant (kcat decreased 1000-fold compared with wild-type EntF) releases both enterobactin (75%) and linear (DHB-Ser)2 dimer (25%) as products. The His 1271-->Ala mutant (kcat decreased 10,000-fold compared with wild-type EntF) releases only enterobactin, but accumulates both DHB-Ser-O-TE and (DHB-Ser)2-O-TE acyl enzyme intermediates. Electrospray ionization and Fourier transform mass spectrometry of proteolytic digests were used to analyze the intermediates. CONCLUSIONS: These results establish that the TE domain of EntF is both a cyclotrimerizing lactone synthetase and an elongation catalyst for ester-bond formation between covalently tethered DHB-Ser moieties, a new function for chain-termination TE domains found at the carboxyl termini of multimodular NRPSs and polyketide synthases.

Amino Acid Sequence↗
PubMed1999

Sexual behavior in Japanese quail as a test end point for endocrine disruption: effects of in ovo exposure to ethinylestradiol and diethylstilbestrol.

Chemicals having a capacity to disturb the endocrine system have attracted considerable interest during recent years. There is a shortage of well-characterized in vivo tests with which to study such disturbances in different classes of vertebrates. In the present study, test end points related to reproduction in the Japanese quail were used to examine the estrogenic activity of chemicals. The synthetic estrogens ethinylestradiol (EE(2)) and diethylstilbestrol (DES), used as model compounds, were injected into the yolk of embryonated eggs. After the birds had been raised to sexual maturity, we examined sexual behavior, plasma testosterone concentrations, and testis morphology in adult males. The lowest doses resulting in a significantly depressed male sexual behavior were 6 ng/g egg for EE(2) and 19 ng/g egg for DES. Testis weight asymmetry was increased at 6 ng EE(2)/g egg, but DES had no effect at any treatment level. The area of the androgen-dependent cloacal gland was significantly reduced at 57 ng DES/g egg. No effects on plasma testosterone concentration or body weight following exposure to EE(2) or DES were observed at any dose level. Depressed male sexual behavior was the most sensitive of the end points studied, and we suggest that this ecologically relevant end point be included in avian in vivo testing for neuroendocrine disruptors.

Animals↗