Lack of association between C385A functional polymorphism of the fatty acid amide hydrolase gene and polycystic ovary syndrome

The endocannabinoid system contributes to the regulation of appetite, food intake and energy balance. Fatty acid amide hydrolase is responsible for degradating anandamide, a key messenger of the endocannabinoid system. C385A is a common, functionally active genetic polymorphism of the gene encoding fatty acid amide hydrolase and has been associated with overweight and obesity. Our aim was to establish whether single nucleotide polymorphism C385A has an association with polycystic ovary syndrome or its clinical features.A monocentric pilot study was performed on 63 patients with polycystic ovary syndrome and 67 healthy control subjects. Anthropometric parameters and laboratory data were acquired from subjects. The alleles of the polymorphism were detected using polymerase chain reaction and subsequent cleavage by Eco130I (StyI) restriction endonuclease verified by direct DNA sequencing.No difference was found in minor allele frequency between patient and control groups. Those patients, carrying the C385A polymorphism were associated with higher free thyroxine hormone levels. In the control group, carriers of the polymorphism had significantly lower insulin levels.Our data indicate that the C385A polymorphism of the fatty acid amide hydrolase gene is not a genetic susceptibility factor for the development of polycystic ovary syndrome. However, the polymorphism might have a role in influencing the synthesis or metabolism of different hormones including thyroxin and insulin.

Meta-analysis of gene expression profiles associated with histological classification and survival in 829 ovarian cancer samples

Transcriptomic analysis of global gene expression in ovarian carcinoma can identify dysregulated genes capable to serve as molecular markers for histology subtypes and survival. The aim of our study was to validate previous candidate signatures in an independent setting and to identify single genes capable to serve as biomarkers for ovarian cancer progression. As several datasets are available in the GEO today, we were able to perform a true meta-analysis. First, 829 samples (11 datasets) were downloaded, and the predictive power of 16 previously published gene sets was assessed. Of these, eight were capable to discriminate histology subtypes, and none was capable to predict survival. To overcome the differences in previous studies, we used the 829 samples to identify new predictors. Then, we collected 64 ovarian cancer samples (median relapse-free survival 24.5 months) and performed TaqMan Real Time Polimerase Chain Reaction (RT-PCR) analysis for the best 40 genes associated with histology subtypes and survival. Over 90% of subtype-associated genes were confirmed. Overall survival was effectively predicted by hormone receptors (PGR and ESR2) and by TSPAN8. Relapse-free survival was predicted by MAPT and SNCG. In summary, we successfully validated several gene sets in a meta-analysis in large datasets of ovarian samples. Additionally, several individual genes identified were validated in a clinical cohort.

Prenatal ultrasonographic measurement of the fetal iliac angle during the first and second trimester of pregnancy

OBJECTIVES

The aim of this study was to present our results of the sonographic measurement of the fetal iliac angle during the first and second trimesters of pregnancy.

METHODS

A total of 2168 fetal iliac angle measurements were performed in a transverse section of the fetal pelvis. The iliac angle measurements were compared in fetuses with trisomy 21 (n = 52) and fetuses with normal karyotype (n = 1980). The sensitivity, specificity, positive predictive value, negative predictive value and false positive rate in trisomy 21 fetuses were compared for multiple cut-off value. Statistical significance for measurements was estimated for trisomy 21.

RESULTS

A total of 2064 fetuses had adequate images for satisfactory measurement of the iliac wing angle and 1831 patients asked for a genetic invasive procedure. Of the fetuses with chromosomal aberrations, only the fetuses with trisomy 21 were included in the investigation. The risk of trisomy 21 in our population was 1 of 39. In the euploid fetuses, the mean iliac wing angle was 63.72°. The mean iliac wing angle in the fetuses with trisomy 21 was 90.32°, significantly higher than those seen in fetuses with normal karyotype.

CONCLUSION

The proven larger iliac wing angle in neonates with Down syndrome can be demonstrated sonographically during the pregnancy, especially in the first and second trimesters. This marker may be useful in prenatal screening or exclusion of trisomy 21.

A snapshot of microarray-generated gene expression signatures associated with ovarian carcinoma

It was hypothesized that analysis of global gene expression in ovarian carcinoma can identify dysregulated genes that can serve as molecular markers and provide further insight into carcinogenesis and provide the basis for development of new diagnostic tools as well as new targeted therapy protocols. By applying bioinformatics tools for screening of biomedical databases, a gene expression profile databank, specific for ovarian carcinoma, was constructed with utilizable data sets published in 28 studies that applied different array technology platforms. The data sets were divided into four compartments: (i) genes associated with carcinogenesis: in 14 studies, 1881 genes were extracted, 75 genes were identified in more than one study, and only 4 genes (PRKCBP1, SPON1, TACSTD1, and PTPRM) were identified in three studies. (ii) Genes associated with histologic subtypes: in four studies, 463 genes could be identified, but none of them was identified in more than a single study. (iii) Genes associated with therapy response: in seven studies, 606 genes were identified from which 38 were differentially regulated in at least two studies, 3 genes (TMSB4X, GRN, and TJP1) in three studies, and 1 gene (IFITM1) in four studies. (iv) Genes associated with prognosis and progression: 254 genes were found in seven studies. From these genes, merely three were identified in at least two different studies. This snapshot of available gene expression data not only provides independently described potential diagnostic and therapeutic targets for ovarian carcinoma but also emphasizes the drawbacks of the current state of global gene expression analyses in ovarian cancer.

Analysis of perioperative morbidity according to whether the uterine cavity is opened or remains closed during abdominal myomectomy--results of 423 abdominal myomectomy cases

For women who desire pregnancy or who wish to retain their uterus, myomectomy is the standard approach for the treatment of fibroids. Abdominal myomectomy seems to be the best choice when there are large subserosal or intramural fibroids (> 5-7 cm), or submucosal fibroids > 3 cm or when multiple fibroids (> 3) are to be removed. When submucosal myomas are present or multiple fibroids are to be removed, opening the uterine cavity during the surgical procedure is more likely to happen. There is lack of published evidence about whether there is any difference in perioperative morbidity and management of those cases where the uterine cavity is opened during the surgical procedure compared with those where the uterine cavity remains closed.

METHODS

We undertook a retrospective review of 423 abdominal myomectomies via either an opened or closed uterine cavity. As a primary outcome we assessed the overall perioperative morbidity rate and as a secondary outcome we compared the necessity of pre and postoperative transfusions, intraoperative bleeding, febrile morbidity, unintended surgical interventions, life-threatening events, need for relaparotomies and duration of hospital stay between the opened and non opened uterine cavity groups.

RESULTS

The overall perioperative morbidity rate was significantly higher in those cases where the uterine cavity was opened during surgery; however the difference was caused only by the increased risk of intraoperative bleeding. All the other variables, such as febrile morbidity, number of relaparotomies, unintended surgical procedures and life-threatening events did not differ between the two groups.

CONCLUSION

Although there is an increased risk of intraoperative bleeding it seems that entering the uterine cavity during abdominal myomectomy can be considered as safe a procedure as in those cases where the uterine cavity remains closed.

Factors affecting reproductive outcome following abdominal myomectomy

PURPOSE

Fibroids may cause infertility and recurrent pregnancy loss. Studies have analysed the reproductive results after myomectomy according to the size, location and number of fibroids removed, but data are insufficient about comparison of opening the uterine cavity or not during surgery.

MATERIALS AND METHODS

Two hundred twenty-nine abdominal myomectomies with the indication of infertility and/or recurrent pregnancy loss were analysed retrospectively. The main purpose was to compare postoperative pregnancy, delivery and miscarriage rates according to either the uterine cavity was opened or not during the surgery. As a secondary outcome postoperative pregnancy rates were assessed by location, size and number of fibroids.

RESULTS

There was no significant difference in reproductive results according to either the uterine cavity was opened or remained closed. Preoperative location, size and number of fibroids did not influence significantly the postoperative pregnancy rates.

CONCLUSION

Opening the uterine cavity does not impair postoperative pregnancy rates. Preoperative location, size and number of fibroids do not influence postoperative reproductive results.

Infections associated with ventricular assist devices: epidemiology and effect on prognosis after transplantation

BACKGROUND

Ventricular assist devices (VADs) can be used as a bridge to orthotopic heart transplantation (OHT) in people with severe congestive heart failure. Although they can be inserted for an indefinite time period (unlike balloon pumps), they do carry a substantial risk of infection. We studied the epidemiology, microbiology, and consequences of infection in patients with VADs who ultimately had cardiac transplantation.

METHODS

Records of VAD-supported patients at our institution between January 1995 and January 2005 were identified by ICD-9 code. Infection was classified as driveline infection, pocket infection, mediastinitis, or VAD endocarditis in increasing severity of illness.

RESULTS

Of 73 patients identified by ICD-9 code, 60 had charts available for review. Of these 60, 72% had a VAD infection: 13 had VAD endocarditis; 3, mediastinitis; 25, pocket infection; and 29, driveline infection. The only association of infection (43 patients, 72%) and demography or underlying disease was that of endocarditis with older age (median age 59 vs. 53 years; P=0.02) and diabetes mellitus (13 patients, 30%; risk ratio 3.4; P=0.01). The duration of VAD support was longer in infected patients (median 125 days) vs. uninfected ones (25 days). Median survival measured from the time of VAD placement (although also true from the time of transplantation) was shorter in patients with VAD endocarditis (120 days) and pocket infection (350 days) vs. no infection (>2400 days) with a significant P=0.017 for endocarditis. Four patients had infections after transplantation that were caused by the same organism as their VAD infection. The predominant pathogens in VAD infection were Staphylococcus and Enterococcus spp.

CONCLUSION

VAD use as a bridge to cardiac transplantation is associated with a large number of device-related infections. Patients with infected VADs, on average, wait longer for transplantation than patients with uninfected VADs, and patients with VAD endocarditis have a shorter survival than patients with no VAD infection or simple driveline infection.

The evolving role of ultrasound in obstetrics/gynecology practice

The value of ultrasound examinations depends heavily on the preparation of the personnel carrying out the examination and the technical capabilities of the equipment they use. Only well-organized regional or national programs are able to provide high level, cost-effective care based on certification of quality. Such certification must include the training of professionals, the definition of competence levels, accreditation of laboratories and the establishment of professional protocols. Together, these factors can guarantee the standard of care and provide legal protection for practitioners. It is worth carrying out routine screening in each pregnancy because the majority of abnormalities occur in pregnancies with low risk. Abnormalities detected on screening cases and the examination of high risk groups should be referred to higher level centers. Here, appropriate technical background and qualified personnel are present to provide cost-effective care. At the same time, necessary invasive interventions can also be performed. A minimum of three screening tests should be performed during pregnancy. The first should be performed at the fetal age of 10-14 weeks to detect abnormalities and pathological conditions in early pregnancy. The second one has to be performed between the fetal ages of 18 and 22 weeks to assess detailed fetal anatomy and rate of development. The third should be performed between the fetal age of 30 and 34 weeks to assess fetal anatomy, rate of development, placentation and circulation. It is worth considering a fourth screening at approximately 36-38 weeks to assess the intrauterine condition of the fetus and determine the appropriate method of delivery. Finally, besides improving the standard of living, education, and hygienic conditions in developing countries, developed countries also have to help improve the standard of pregnancy care. Within this context, the dissemination of diagnostic ultrasound must be given special emphasis.

Assessment of uterine circulation in ectopic pregnancy by transvaginal color Doppler

OBJECTIVE

The aim of our study was to determine the effect of abnormal implantation on uterine circulation and to evaluate whether the assessment of uterinal blood flow can provide additional information for the diagnosis of tubal pregnancies.

METHODS

Forty-nine patients with ectopic pregnancy were examined by transvaginal color Doppler immediately before surgery. Resistance and pulsatility indices of blood flow in the uterine and tubal arteries were measured.

RESULTS

The blood flow parameters of the uterine and tubal arteries did not change with gestational age. There was a significant increase in blood flow on the side with the tubal gestation. Differences between sides were higher in the tubal arteries than in the main uterine arteries and showed no dependence on gestational age.

CONCLUSION

The abnormal implantation and tubal trophoblast invasion in ectopic pregnancy (EP) can cause more marked blood flow changes in the adjacent supplying vessels than in the main uterine arteries.

Cone differentiation with no photopigment coexpression

PURPOSE

To decide whether the transitory coexpression of cone visual pigments described in the developing rat and gerbil retina is a universal feature of dichromatic mammalian species.

METHODS

The rabbit, a species widely used in eye research, was selected for the study and a search made for the presence of cones that bound more than one cone antibody during the first postnatal week. To plot the densities of individual cone types and to colocalize the two visual pigments, immunocytochemistry on retinal wholemounts and consecutive tangential sections, respectively, were used.

RESULTS

The sequence in which the visual pigments began to be expressed was the same as that observed in other mammals: first, rhodopsin; second, blue pigment; and last, green pigment. The striking increase in blue cone density numbers observed in the rat, however, did not occur in the rabbit. Instead, some days after the first blue cones appeared, the green cones also started to express their visual pigment, and this cone type soon outnumbered the blue cones. Within the limits of the immunocytochemical method, it was established that unlike the developing rat, the presence of double-labeled cones was not a character of the rabbit retina.

CONCLUSIONS

Visual pigment coexpression is an interesting phenomenon of retinal development, however, it is not the exclusive scenario of photoreceptor differentiation. Each species must be carefully studied before deciding whether its retinal cones synthesize both pigments during retinal development.

Photoreceptor distribution in the retinas of subprimate mammals

Relevant data on the distribution of color cones are summarized, with special emphasis on the marked dorsoventral asymmetries observed in a number of mammalian species. In addition, an overview is given of studies that demonstrate the coexistence of two visual pigments within the same cone cell. The biological significance of these phenomena is discussed in conjunction with comparative immunocytochemical analyses of subprimate retinas. Based on various cone distribution patterns and temporal and spatial visual pigment coexpression, two models of cone photoreceptor differentiation are suggested.

Human pancreatic leiomyosarcoma (PZX-7) growing as a serially transplantable xenograft in immunosuppressed mice

BACKGROUND

Several human leiomyosarcoma xenografts have been established, but pancreatic smooth muscle sarcomas have never been serially transplanted and investigated.

METHOD

Immunosuppression of CBA/CA mice was achieved by thymectomy, whole-body irradiation, and bone marrow reconstruction. Tumor fragments were subcutaneously implanted from a Grade III pancreatic leiomyosarcoma and serially passaged for more than 24 mo. The xenografted tumors were characterized by morphological, morphometrical, biochemical, and flow cytometric methods.

RESULTS

The tumor has retained its characteristic morphology and no further differentiation occurred. The mitotic counts and the amount of the connective tissue all remained constant. The calculated volume doubling time was 11.3 d. Immunohistochemically, the tumor proved to be p53-negative, but the strong expression of the bcl-2 remained as a constant feature throughout successive transplantations. The DNA index and the proliferation indices did not change significantly with the time (mean DI: 1.65, range: 1.561-1.70; mean PI: 17.9%, range: 15.3-20.7%). Lactose dehydrogenase (LDH) isoenzyme electrophoresis evidenced a retained human pattern of the tumor even after 32 mo of transplantations.

CONCLUSION

The first human pancreatic leiomyosarcoma xenograft (PZX-7) growing in immuno-suppressed mice is described and characterized.

Effects of fibrates on the glycine conjugation of benzoic acid in rats

In the course of glycine conjugation, benzoic acid is successively converted into benzoyl-CoA and benzoylglycine by mitochondrial enzymes (i.e. benzoyl-CoA synthetase and benzoyl-CoA/glycine N-acyltransferase, respectively), utilizing ATP, CoA, and glycine. Large doses of benzoate deplete CoA from the liver, suggesting that the supply of CoA may limit the capacity for glycine conjugation. Because fibrates are known to increase hepatic CoA synthesis, we examined whether treatment with fenofibrate or bezafibrate enhanced the capacity of rats to conjugate benzoic acid with glycine. Dietary administration of fenofibrate or bezafibrate (2.5 mmol/kg of feed, for 10 days) increased hepatic CoA levels 8-10-fold, while not affecting hepatic ATP levels; only fenofibrate elevated, albeit moderately, the concentration of glycine in liver. Hepatic mitochondria isolated from fibrate-fed rats, compared with those from controls, exhibited unchanged benzoyl-CoA synthetase activity but higher benzoyl-CoA hydrolase and lower benzoyl-CoA/glycine N-acyltransferase activities. Feeding with either fibrate increased liver mass by 50-60%. Control and fibrate-fed rats were administered benzoate at different doses, one to produce a large demand for CoA (i.e. 2 mmol/kg, iv) and two others to produce smaller demands for CoA (i.e. 1 mmol/kg or 2 mmol/kg plus glycine, iv). Fenofibrate-fed rats, and to a lesser extent bezafibrate-fed animals, exhibited increased glycine conjugation capacity, as indicated by faster disappearance of benzoate from the blood and appearance of benzoylglycine in the blood and urine, compared with controls; however, fibrates were not more effective in rats receiving the benzoate dose that produced the greatest demand for CoA. In contrast, benzoylglycine formation from benzoate (0.1-1 mM) was not enhanced in liver slices from fibrate-fed rats; moreover, it was lower than control levels in slices from bezafibrate-fed animals. Bezafibrate, but not fenofibrate, given to rats in a single dose (0.5 mmol/kg, ip) decreased the elimination and glycine conjugation of benzoate, indicating that bezafibrate is a direct inhibitor of glycine conjugation. In summary, fibrates influence glycine conjugation in a complex manner. Some fibrate-induced alterations (i.e. increased benzoyl-CoA hydrolase and decreased glycine transferase activities and direct inhibition by bezafibrate) can potentially hinder conjugation of benzoate with glycine, thus precluding conclusions regarding whether increased CoA availability enhances glycine conjugation. Fibrate-induced hepatomegaly appears to significantly contribute to the increased glycine conjugation capacity of rats treated with fenofibrate or bezafibrate.

Position- and base pair-specific comparison of p53 mutation spectra in human tumors: elucidation of relationships between organs for cancer etiology

A new approach to analyze the p53 mutation database of the European Molecular Biology Laboratory for a comparison of mutation spectra is described, with the aim of investigating organ specificity of etiological factors and putative organ-to-organ relationships in cancer pathogenesis. The number of entries of each nucleotide- and base-pair substitution-specific mutation was divided by the total number of tumors analyzed. For each organ pair, the difference of the mutation-specific frequency differences was calculated. Resulting values could range from 0 (full concordance) to 2 (full discordance). Skin, lung, and urinary bladder showed highly independent mutation spectra (maximum discordance value = 1.48 for skin versus brain), in agreement with the presence of specific factors responsible for a large number of the respective tumors (UV light, smoking, aromatic amines). The three organs with the smallest sum of discordance values were mammary gland (breast), colon and esophagus. The minimum organ-to-organ discordance value was 0.95, for stomach versus colon. For these organs, common, possibly also endogenous, cancer risk factors could be postulated as contributing to the observed mutation spectrum. The remaining cancers (ovary, sarcoma, leukemia/lymphoma, brain, head and neck, and stomach, in order or increasing discordance) were of intermediate range and showed a mix of values. Reasons for close relationship to some of the other organs and marked differences to others are discussed. Exclusion of the "hot-spot" mutations did not markedly alter the observed relationships, indicating that a putative selective growth advantage does not cover up the etiological basis for the observed mutation spectrum. It is expected that much more insight into carcinogenesis and cancer could be gained by further exploratory analyses of mutation databases.

Does hepatic ATP depletion impair glycine conjugation in vivo?

Conjugation with glycine, a reaction important in the elimination of carboxylic acids (e.g. benzoic and salicylic acids), takes place in hepatic mitochondria and uses ATP, coenzyme A, and glycine. Although normal ATP supply does not limit glycine conjugation in vivo (Gregus, Z., et al., Drug Metab. Dispos. 20, 234, 1992), ATP deficiency may impair it. This hypothesis was tested by examining the effect of ATP depletors (oligomycin, fructose, and ethionine) on glycine conjugation and elimination of benzoic acid in rats. Pretreatment with the mitochondrial ATP synthesis inhibitor oligomycin (0.5-2 mg/kg, intraportally) decreased glycine conjugation of benzoic acid markedly and in a dose-dependent manner, as indicated by the delayed elimination of benzoate and delayed appearance of benzoylglycine in blood. Oligomycin also dramatically diminished urinary excretion of benzoylglycine, because it inhibited not only formation of benzoylglycine from benzoate, but also the renal transport of benzoylglycine. Treatment with fructose (a consumer of both cytosolic and mitochondrial ATP) or ethionine (a consumer of cytosolic ATP) depleted hepatic ATP from approximately 2.5 micromol/g to levels comparable with those observed after administration of 1 mg/kg oligomycin (approximately 1.2 micromol/g). Despite this, elimination of benzoate and formation of benzoylglycine were decreased less by fructose than by oligomycin and only negligibly by ethionine. ATP depletors did not influence hepatic glycine levels, and only oligomycin lowered coenzyme A levels in liver. However, the oligomycin-induced decline of hepatic coenzyme A levels was delayed, contrary to impairment of glycine conjugation, which was almost immediate. In summary, impairment of benzoylglycine formation by ATP depletors apparently correlates with their capacity to diminish ATP levels in hepatic mitochondria (i.e. at the site of glycine conjugation). These observations suggest that limited availability of mitochondrial (but not cytosolic) ATP reduces glycine conjugation capacity. Therefore, mitochondrium toxic agents and pathological mitochondrial injuries acting in liver may compromise glycine conjugation by decreasing ATP supply.

Comparative susceptibilities of Klebsiella species, Enterobacter species, and Pseudomonas aeruginosa to 11 antimicrobial agents in a tertiary-care university hospital

The in vitro activity of cefepime was compared versus that of 10 antimicrobial agents commonly used in the treatment of serious infections caused by common aerobic gram-negative bacteria: aztreonam, cefoperazone, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, piperacillin, ticarcillin-clavulanic acid, and tobramycin. We tested 30 clinical isolates representing a cross section of Klebsiella and Enterobacter species and Pseudomonas aeruginosa collected at our tertiary-care university hospital. The most potent beta-lactams were imipenem and cefepime, which demonstrated significant activity against the majority of strains in all 3 genera of bacteria tested, as did ciprofloxacin and tobramycin. Ceftazidime was active against Pseudomonas aeruginosa but was less potent against Klebsiella and Enterobacter spp. Cefoperazone and ceftriaxone were less active than ceftazidime against Pseudomonas aeruginosa. Cefepime was found to be highly active against many resistant organisms that traditionally have been difficult to treat.

Lipoic acid impairs glycine conjugation of benzoic acid and renal excretion of benzoylglycine

Glycine conjugation of benzoic acid is catalyzed by the mitochondrial enzymes benzoyl-coenzyme A(CoA) synthetase and benzoyl-CoA: glycine N-acyltransferase and requires ATP, CoA, and glycine as cosubstrates. Lipoic acid (LA), an important endogenous and also therapeutic compound, depletes hepatic CoA; therefore, it may interfere with glycine conjugation. To test this hypothesis, LA (0.5-1.5 mmol/kg ip) was given to anesthetized, glycine-loaded rats 1 hr before administration of benzoic acid (1 mmol/kg iv). LA inhibited glycine conjugation of benzoic acid in a dose-dependent manner as indicated by: 1) reduced clearance of benzoic acid from blood; 2) delayed appearance of benzoylglycine in blood; and 3) decreased excretion of benzoylglycine in urine. LA also decreased urinary excretion of injected benzoylglycine, indicating that reduced excretion of this metabolite after benzoic acid injection is caused by diminished formation and impaired renal transport of benzoylglycine. Urine formation was decreased by LA in a dose-dependent fashion, and acute renal failure was evident in rats receiving the highest dose. LA depleted hepatic CoA, carnitine, and glutathione, but not ATP, whereas it increased the hepatic concentration of glycine. In isolated and solubilized rat liver mitochondria, LA inhibited both benzoyl-CoA synthetase (IC50 approximately 1.5 mM) and benzoyl-CoA:glycine N-acyltransferase (IC50 approximately 0.3 mM). Thus, depletion of CoA and inhibition of the pertinent enzymes seem responsible for impairment of glycine conjugation of benzoic acid by LA. LA may also impair renal tubular cell function, compromising the tubular secretion of benzoylglycine and causing acute renal failure.

Dose-time response in mouse skin tumor induction by 7, 12-dimethylbenz[a]anthracene and 12-O-tetradecanoyl-phorbol-13-acetate

The question was addressed whether the dose-response relationship derived from a carcinogenicity study can be used for mechanistic interpretation and to what extent the shape of the curve is dependent on the duration of the bioassay and the time of analysis. The mouse skin tumor model was used. It allows recording of the time of tumor appearance without interim sacrifice. Groups of 16 female NMRI mice were treated twice weekly by dermal administration with combinations of (a) 2.5 nmol 12-O-tetradecanoyl-phorbol-13-acetate (TPA) plus 0, 0.3, 1, 3, or 10 nmol 7,12-dimethylbenz[a]anthracene (DMBA) or with (b) 2.5 nmol DMBA plus 0, 0.1, 0.3, 1, 3, or 10 nmol TPA. The appearance of the first papilloma was recorded for each animal and the cumulative incidence data were analyzed in two ways: (i) With the usual dose-prevalence representation at a fixed time point, the dose response for TPA was sigmoidal, while it was linear-superlinear for DMBA. This was observed at all time points, indicating that the dose-response information may be used for a distinction between DNA-reactive and tumor-promoting mechanisms of action. (ii) When time-to-tumor and loss of tumor-free lifetime was analyzed as a function of dose, there was again a marked difference between DMBA and TPA. The tumor-free lifetime increased with each step of dose reduction but the slope was about four times larger for TPA compared with that for DMBA. Further reduction of the TPA dose could result in a situation in which the natural life span sets a limit to an observable effect. Under the conditions of this bioassay for mouse skin papilloma induction by a combination treatment with DMBA plus TPA, the findings support the idea of a no-effect low-dose threshold for the tumor-promoting agent.

Endogenous and exogenous factors in carcinogenesis: limits to cancer prevention

Organ-specific cancer incidence rates can vary dramatically between low- and high-incidence areas. Such differences are due to (1) heritable susceptibility determinants, (2) risk factors associated with the environmental and local living conditions (e.g., viruses, pollution), and (3) personal life-style factors. For organs showing large differences between cancer registries, exogenous factors might be most important, while for organs showing only small differences, endogenous and unavoidable factors are expected to be more important. In this paper, a working hypothesis based on descriptive cancer epidemiology is presented to estimate, in a quantitative manner, the unavoidable contribution to the process of carcinogenesis and to discuss limitations to individual cancer prevention. Cumulative cancer incidence rates for a 75-year period of life (CR74, in percent) were taken from IARC Scientific Publication No. 120 (1992). For each organ, values were ranked in ascending order, and the ratio between high-rate and low-rate registries (90th percentile/10th percentile) was determined. This measure of variability among registries differed strongly between organs. Largest ratios were seen for organs with well-known exogenous risk factors, such as pharynx, lip, tongue, mouth, liver, esophagus, and melanoma in males, and lung, esophagus, gallbladder, liver, and bladder in females. Small ratios were seen for rectum, brain, colon, and Hodgkin's disease in males, and breast, rectum, ovary, brain, and colon in females. It is concluded that the process of carcinogenesis in the latter organs has a stronger endogenous/unavoidable component, for some tissues possibly of hormonal type. A fictitious population was composed where, for each organ, the minimum reported cancer rate was taken. When based on all cancer registries world-wide, CR74 sums over all sites of 2.0% and 2.3% resulted in males and females, respectively. When only Central/Western European countries were included in the analysis in order to reduce differences in risk factors nos. 1 and 2, the sum of the minimum values was 10.4% and 8.7%. After correction of the data for smoking, 'minimum' cancer incidence rates in males and females were estimated to be 7.6% and 6.8%. Based on a median cancer incidence rate for nonsmoking males in Europe of about 21%, therefore, individual preventive measures taken by a nonsmoker can reduce the cancer risk, on average, 'only' by a factor of about 3. A considerable fraction of cases thus appears to be hardly avoidable.

Investigation of a pseudo-outbreak of orthopedic infections caused by Pseudomonas aeruginosa

OBJECTIVE

To report a pseudoepidemic of Pseudomonas aeruginosa infections discovered during an investigation of postoperative joint infections.

DESIGN

A retrospective review of case patients' hospital charts, operative reports, and laboratory data, as well as environmental culturing, polymerase chain reaction (PCR) ribotyping of outbreak isolates, and in vitro analysis of P aeruginosa growth characteristics.

SETTING

A 510-bed, university-affiliated adult tertiary care hospital.

RESULTS

Between October 1 and December 1, 1992, seven postsurgical joint infections were diagnosed, including four caused by P aeruginosa. A bottle of "sterile" saline used to process tissue specimens was found to be contaminated with P aeruginosa. Further investigation revealed that P aeruginosa had grown from seven additional tissue cultures, all of which had been processed with the contaminated saline. PCR ribotypes of the contaminant matched those of the clinical isolates. In vitro, P aeruginosa strains were viable in commercial nonbacteriostatic saline, but never caused visible turbidity. Six patients received antibiotics for their presumed infections; four patients had peripherally inserted central catheters placed, and one experienced severe anaphylactic reactions to several antibiotics.

CONCLUSIONS

Pseudoepidemics due to common organisms are often difficult to detect, and delayed recognition can result in substantial morbidity. This outbreak investigation illustrates the potential for contamination of diluents in the microbiology laboratory and emphasizes the need for meticulous quality control.

A comparison of serial plate agar dilution, Bauer-Kirby disk diffusion, and the Vitek AutoMicrobic system for the determination of susceptibilities of Klebsiella spp., Enterobacter spp., and Pseudomonas aeruginosa to ten antimicrobial agents

The use of rapid, automated technologies for assessment of antimicrobial susceptibility and determination of minimum inhibitory concentrations has been evolving for over a decade. We compared the Vitek AutoMicrobic system and Bauer-Kirby disk diffusion with the National Committee for Clinical Laboratory Standards methods of serial plate agar dilution for qualitative and quantitative susceptibilities of 301 hospital isolates of Klebsiella spp., Enterobacter spp., and Pseudomonas aeruginosa. Antibiotics tested were aztreonam, cefoperazone, ceftazidime, ceftriaxone, ciprofloxacin, gentamicin, imipenem, piperacillin, ticarcillin-clavulanic acid, and tobramycin. Agar dilution and Bauer-Kirby results were more strongly correlated for all three genera than were the results for agar dilution and Vitek. If agar dilution is presumed to be the "gold standard," Bauer-Kirby disk diffusion had only half the number of false susceptibles as did the Vitek. Thus, the Vitek AutoMicrobic system seems to be somewhat less reliable for both qualitative and quantitative measurement of susceptibility and resistance than is Bauer-Kirby disk diffusion.

Effect of valproic acid on glycine conjugation of benzoic acid

Conjugation with glycine proceeds through ATP-dependent coupling of carboxylic acids with coenzyme A (CoA). Therefore, chemicals that form CoA esters may interfere with glycine conjugation. We tested the hypothesis that valproic acid (VPA), which is esterified with CoA in the first step of its mitochondrial beta-oxidation, may compromise glycine conjugation of aromatic carboxylic acids, by investigating the effect of acute VPA administration on glycine conjugation of benzoic acid in rats. VPA administered 1 hr before injection of benzoate only decreased the blood clearance of benzoate and the urinary excretion of benzoylglycine slightly in normal rats. However, in rats loaded with glycine, 2 and 3 mmol/kg of VPA reduced the blood clearance of benzoate by 34 and 59%, diminished the peak blood level of the glycine conjugate and depressed the maximal urinary excretion rate of benzoylglycine by 28 and 66%, respectively. To elucidate the mechanism of VPA-induced inhibition of benzoylglycine formation, the effects of VPA on hepatic levels of cosubstrates and the activities of enzymes involved in glycine conjugation were also determined. One hour after administration of VPA, hepatic ATP levels remained unchanged, whereas the concentration of CoA was reduced by 67 to 73% and that of glycine was increased by 58 to 67%. Activities of the enzymes of glycine conjugation were not influenced by VPA. However, 2-n-propyl-4-pentenoic acid, a metabolite of VPA, inhibited benzoyl-CoA synthetase. In summary, VPA minimally influenced the capacity of glycine conjugation of benzoic acid in normal rats, but decreased it markedly in glycine-loaded rats.(ABSTRACT TRUNCATED AT 250 WORDS)

Dependence of glycine conjugation on availability of glycine: role of the glycine cleavage system

1. Glycine conjugation of benzoic acid was investigated in anaesthetized rats by measuring the disappearance of benzoate from blood, and the appearance of benzoylglycine in blood and urine. 2. Administration of glycine (1-10 mmol/kg,i.v.) increased the capacity of benzoylglycine formation in a dose-dependent fashion, with a maximal rate (8.1 mumol/kg per min) occurring after administration of 5 mmol/kg glycine. The normal endogenous glycine supply (1.7 mM in liver) permits glycine conjugation only at an approximate half-maximal rate (4.5 mumol/kg/per min). 3. The increase in benzoylglycine formation in response to exogenous glycine supply is also a function of the benzoate dosage. Decreased responsiveness at high benzoate dosage indicates that the availability of coenzyme A is another factor that also limits the capacity of glycine conjugation. 4. Cysteamine (200 mg/kg, i.p.), a potent inhibitor of the mitochondrial glycine cleavage system, rapidly increased hepatic glycine concentration 2-3-fold without affecting the concentration of the other co-substrates (i.e. coenzyme A and ATP) of glycine conjugation. 5. Administration of cysteamine increased the blood clearance of benzoate by 50%, the appearance of benzoylglycine in blood, and the urinary excretion of benzoylglycine. 6. It is concluded that the activity of glycine cleavage system is an important determinant of glycine supply and, thereby, the capacity of glycine conjugation of xenobiotics.

Antimicrobial susceptibility testing of Neisseria gonorrhoeae and implications for epidemiology and therapy

Antimicrobial susceptibility testing (AST) of Neisseria gonorrhoeae has been under development since the early days of antimicrobial agents. However, it is rarely applied to clinical isolates today. The history of the various in vitro tests to determine the susceptibility of N. gonorrhoeae to antibiotics is rich with evidence that these results predict response to therapy for almost all agents tested. Further, AST is a useful and important aspect of strain characterization and disease epidemiology in conjunction with the more specific but laborious techniques of auxotyping, serotyping, and plasmid analysis. Current technology has overcome many of the objections to AST for N. gonorrhoeae with standardization of test media and the development of an accurate disk diffusion AST method that is suited to most clinical laboratories regardless of volume or level of technical expertise. Ironically, the very low level of resistance to the current primary treatment strategy in the United States, ceftriaxone or another potent cephalosporin, makes the use of AST somewhat superfluous.

Availability of glycine and coenzyme A limits glycine conjugation in vivo

Using benzoic acid as substrate, this study tested the hypothesis that capacity limitation of glycine conjugation in vivo is due to substrate-induced depletion of hepatic cosubstrates (i.e., ATP, coenzyme A, and glycine) utilized in the conjugation reaction. Benzolyglycine formation was investigated by following the disappearance of benzoic acid from blood and appearance of benzoylglycine in blood and urine after administration of sodium benzoate (0.2-2 mmol/kg, iv) to anesthetized rats whose urine formation was stimulated by mannitol administration. Capacity limitation of glycine conjugation is indicated by (a) the gradual dose-dependent reduction of benzoate blood clearance from 39 ml/min/kg at 0.2 mmol/kg benzoate to 3.7 ml/min/kg at 2 mmol/kg, and (b) the tendency to attain maximal blood levels and urinary excretion rates of benzoylglycine after administration of 0.5-1 mmol/kg benzoate. The maximal urinary excretion rate of benzoylglycine after benzoylglycine administration exceeded the maximal excretion rate of endogenously formed benzoylglycine (approximately 5 mumol/kg/min) 5-fold. This suggests that the urinary excretion rate of endogenously formed benzoylglycine reflects the rate of its formation. Benzoate depleted hepatic glycine (to 40%) and coenzyme A (to 14%) in a dose-dependent fashion; however, it did not change ATP levels in liver. The pattern of this dose-dependent cosubstrate depletion suggests that benzoate primarily causes consumption of hepatic glycine which, at high substrate dosage, leads to marked depletion of coenzyme A in the liver. Thus, these observations indicate that capacity-limited glycine conjugation may be due to limited availability of glycine and coenzyme A for the conjugation process.

Susceptibility of Neisseria gonorrhoeae to cefpodoxime: determination of MICs and disk diffusion zone diameters

We studied the susceptibilities of 77 strains of Neisseria gonorrhoeae to four antibiotics: cefpodoxime, ceftriaxone, penicillin, and tetracycline. All strains were susceptible to ceftriaxone. Cefpodoxime MICs (range, 0.001 to 0.125 micrograms/ml) were parallel to and approximately four times those of ceftriaxone, and all strains will probably be considered susceptible to cefpodoxime. Disk diffusion zone diameters for cefpodoxime ranged from 35 to 57 mm. Of the strains, 32% were penicillin resistant and 51% were tetracycline resistant (MIC, greater than or equal to 2 micrograms/ml). Susceptibility measurements were consistent for disk diffusion zone diameter and MIC, with an overall agreement of 215 of 225 (96%) for ceftriaxone, penicillin, and tetracycline combined. On the basis of these in vitro data, cefpodoxime should be evaluated in the treatment of gonorrhea.

Infections with Chryseomonas luteola (CDC group Ve-1) and Flavimonas oryzihabitans (CDC group Ve-2) in neurosurgical patients

During a 20-month period at Temple University Hospital, three cases of infection with bacteria of the Ve group--Chryseomonas luteola (CDC group Ve-1) and Flavimonas oryzihabitans (CDC group Ve-2)--were seen in neurosurgical patients. Two of the patients, including one with what is thought to be the first reported case of meningitis due to C. luteola, had complications caused by prosthetic material. A review of the literature revealed 14 well-described cases of infection with C. luteola or F. oryzihabitans, the majority of which were cases of bacteremia or peritonitis in patients undergoing dialysis. The presence of foreign material and the use of corticosteroids may predispose to and influence the course of disease. As prosthetic material becomes even more widely used, the incidence of infection with bacteria of the Ve group will likely increase and the manifestations of the infections will probably become more varied.

Microalbuminuria, as predictor of late diabetic complications. A prospective study

To assess the predictive value of microalbuminuria (M) for diabetic macro- and microangiopathy, neuropathy and some related risk factors studies were carried out in 105 diabetic subjects. All examinations were repeated after one year. Microalbuminuria was found to parallel all late diabetic complications, at the beginning of investigations and also after a one-year evolution. It also positively correlated with some risk factors for angiopathy, such as plasma lipid parameters, blood pressure, body mass index and duration of disease.

Controversies in the prevention of infective endocarditis related to dental procedures

There is a long historical relationship between dental procedures and infective endocarditis. Yet despite the availability and wide use over the past three decades of inexpensive, relatively safe antibiotics before dental work, the incidence of endocarditis has not decreased. Can any conclusion be drawn about the merits of antibiotic prophylaxis around the time of dental procedures? If so, is there a preferred regimen? This article outlines the historical developments that have led to current recommendations and presents a critique of current opinion on the advisability of specific programs to prevent cardiac infections related to professional dental work.

Susceptibility to cephalosporins of penicillin-susceptible and penicillin-resistant strains of Neisseria gonorrhoeae from Philadelphia

Using agar dilution, we determined MICs of penicillin, cefoxitin, ceftriaxone, cefmetazole, tetracycline, and spectinomycin for 129 strains of Neisseria gonorrhoeae. All strains were susceptible to ceftriaxone (MIC range, less than or equal to 0.008 to 0.06 micrograms/ml) and spectinomycin (16 to 32 micrograms/ml). The MICs for 50, 90, and 100% of strains tested were 1.0, 2.0, and greater than 8.0 micrograms/ml; 0.12, 1.0, and greater than 8.0 micrograms/ml; 0.5, 1.0, and 2.0 micrograms/ml; and 1.0, 2.0, and greater than 8.0 micrograms/ml for cefmetazole, penicillin, cefoxitin, and tetracycline, respectively. Seven strains were beta-lactamase producers; eight were chromosomally resistant to penicillin. There was a log-linear relation for non-beta-lactamase-producing strains between the MICs of cefmetazole, cefoxitin, and tetracycline and the MIC of penicillin (Pearson r = 0.787, 0.544, and 0.358, respectively).

Strongyloidiasis in an institution for mentally retarded adults

A serologic and epidemiologic survey was undertaken to explain the high incidence of eosinophilia (14.1%) in nine of 64 residents of a facility for mentally retarded adults in Pennsylvania. Seven residents had antibodies to Strongyloides stercoralis as determined by an IgG enzyme-linked immunosorbent assay system (10.9%) and five (71.4%) of this subset had persistent eosinophilia, suggesting a strong association. Sex, race, age, ward, degree of retardation, and medication were not associated with eosinophilia. Stool examination revealed S stercoralis larvae in two residents with S stercoralis antibodies and eosinophilia. Follow-up studies after thiabendazole treatment of the residents with S stercoralis antibodies showed resolution of eosinophilia and disappearance of S stercoralis antibodies in most. Eosinophilia in an adult institutional setting may be associated with strongyloidiasis, even in a nonendemic area. The enzyme-linked immunosorbent assay for antibody to S stercoralis may be useful in diagnosing or monitoring therapy of strongyloidiasis.

Plasma lipoproteins in chronic obstructive pulmonary disease

Plasma lipoprotein fractions have been assessed in 29 patients with chronic obstructive pulmonary disease (COPD), and compared with non-COPD subjects. Triglycerides were significantly lower in COPD females only, the other parameters being almost identical. Thus, the atherosclerosis index of plasma lipoproteins in COPD did not differ almost at all from that of non-COPD subjects, demonstrating that the low prevalence of angina and/or myocardial infarction in COPD patients is not only a consequence of reduced coronary atherosclerosis.

Activity of cefazolin and two beta-lactamase inhibitors, clavulanic acid and sulbactam, against Bacteroides fragilis

One hundred clinical isolates of the Bacteroides fragilis group of bacteria were tested by agar dilution for susceptibility to cefazolin alone or in combination with clavulanic acid or sulbactam. For cefazolin, the MIC for 50% of the isolates (MIC50) was 32 micrograms/ml, the breakpoint for susceptibility. With the addition of 0.5 micrograms of clavulanic acid per ml, the MIC for 90% of the isolates (MIC90) was 8 micrograms/ml, well within the achievable range of concentrations in serum or tissue. Similarly, with the addition of 0.5 micrograms of sulbactam per ml, the MIC90 was 16 micrograms/ml. The addition of a higher concentration (4.0 micrograms/ml) of clavulanic acid or sulbactam resulted in MIC90S which were fourfold lower than those with 0.5 micrograms/ml. A fixed ratio of cefazolin-beta-lactamase inhibitor of 4:1 resulted in an MIC50 and MIC90 which were intermediate between the 0.5- and 4.0-micrograms/ml fixed concentration of beta-lactamase inhibitor.

Glycaemic control and reticulocyte count in diabetic patients

Correlation coefficients between glycosylated haemoglobin, mean fasting glycaemia, and reticulocyte count have been assessed in 61 diabetic patients. When excluding those with overt anaemia and with serum iron below 12.5 mumol/l, the correlations became significant. Thus, reticulocyte count may be a useful indicator of glycaemic control (paralleling HbgAIc), provided anaemia and low serum iron are excluded.

Vascular risk factors in the obliterative peripheral arteriopathy of diabetic patients

To estimate the role of some vascular risk factors in the obliterative arteriopathy of diabetic patients, 71 subjects have been investigated: diabetics without arteriopathy, diabetics with arteriopathy and non-diabetics with arteriopathy. Age, sex, body weight, smoking habits, blood pressure, sedentary life style, diabetes therapy, plasma glucose, cholesterol, triglycerides, total lipids, HDL-cholesterol, uric acid, and fibrinogen have been assessed, the parameters investigated. The results show that the risk factors studied maintain their role even in the obliterative peripheral arteriopathy of diabetic patients; however, there are differences in the relative importance of some of them.

Fibrinolysis in diabetes mellitus. Role of overweight and hypertriglyceridemia

The variations of dilute blood clot lysis time (DBCLT) in 103 diabetic patients were investigated in terms of insulin dependency, body weight, serum lipids and presence of diabetic vascular diseases. The results showed that DBCLT was significantly longer in the 34 overweight diabetic patients (437 +/- 68 min) than in the 69 diabetics at or below the ideal body weight (240 +/- 28 min) or in the 76 normalipidemic normal weight control subjects (253 +/- 12 min). DBCLT was also longer in the hypertrigliceridemic diabetic patients than in the normolipidemic ones. The mean lysis time was similar in diabetic patients with and without retinopathy. However, a higher level of fibrinolytic inhibitors was found in patients with diabetic small vessel disease. In vitro inhibition of plasma factor XIII by p-chlormercuribenzoate (PCMB) caused an acceleration of DBCLT and the differences between lysis time in the overweight diabetics and in the controls were attenuated. These results suggested that deficient thrombolysis is rather due to overweight and to disturbances of lipid metabolism than to diabets and/or its vascular complications and that enhanced fibrin crosslinking is at least partially responsible for delayed clot lysis.

Arterial hypertension in diabetic patients. Role of obesity

In order to assess the role of obesity and to correlate it with other possible factors which cause the well-known higher prevalence of arterial hypertension in diabetic patients without nephropathy, 829 non-proteinuric diabetic outpatients and 856 controls have been investigated. A significantly higher prevalence of arterial hypertension was found in obese patients than in normal-weight subjects. Likewise, hypertensive diabetic patients were more frequently obese than those with normal blood pressure. Arterial hypertension was more often encountered in female diabetics, since women were more obese. The duration of diabetes and age-related increase of arterial hypertension was augmented by the presence of obesity. The practical implications of the observations are emphasized.