[T lymphocyte immunological response to different antigenic fractions of Mycobacterium bovis in juvenile chronic polyarthritis]

BACKGROUND

The possible relationship of stress or heat-shock proteins (hsp) with the pathogenesis of autoimmune disease has been intensely studied recently. In adult rheumatoid arthritis, a bacterial hsp (65 kDa hsp from Mycobacterium tuberculosis or bovis) would have a cross reactivity with a hsp of ARTICULAR cartilage.

AIM

To assess the cellular immune response to the 65 kA hsp from M Bovis in children.

PATIENTS AND METHODS

The proliferative response of peripheral mononuclear cells of 20 children with juvenile chronic polyarthritis and 20 healthy controls, against the 65 kDa hsp and other antigenic fractions from M bovis, was studied.

RESULTS

Patients with juvenile chronic polyarthritis had a intense reaction against 65 kDa fraction and a second fraction located between 32.5 and 27.5 kDa. Patients with a prolonged evolution of the disease (more than five years), reacted preferentially to an antigenic segment located between 32.5 and 27.5 kDa and those with a shorter evolution did so with an antigen of 27.5-18.5 kDa.

CONCLUSIONS

These results support the hypothesis that 65 kDa hsp from M bovis is involved in the pathogenesis of chronic juvenile polyarthritis and suggest that patients with short or prolonged evolutions of the disease would react to different antigenic fractions.

Epidemic and endemic seroprevalence of antibodies to Cryptosporidium and Giardia in residents of three communities with different drinking water supplies

This study was carried out to compare cryptosporidiosis and giardiasis seroprevalence rates in residents of three communities. Community (Com 1) uses drinking water from deep wells, community 2 (Com 2) uses surface water from a protected watershed, and community 3 (Com 3) uses surface water frequently containing Cryptosporidium oocysts and Giardia cysts. Unfiltered drinking water from each community was collected at the tap and tested for Cryptosporidium oocysts and Giardia cysts during the 12 months in which sera were collected for testing. No oocysts or cysts were detected in the water from the Com 1 deep wells; oocysts and cysts were detected intermittently in the drinking water from the other two communities. A waterborne outbreak of cryptosporidiosis occurred in a municipality adjacent to Com 3 six months into this 12-month study. Sera from residents of each of the communities were collected proportionately by month and by population size. Coded sera were tested for IgG to Cryptosporidium using a previously developed Western blotting method. The presence or absence of bands at 15-17 kD and/or 27 kD was recorded for the 1,944 sera tested. Definite bands at 15-17 kD and/or 27 kD were detected in 981 (50.5%) of the sera. A total of 33.2% of sera from Com 1 (community using deep wells) were positive using the same criteria compared with 53.5% (Com 2) and 52.5% (Com 3) of sera from the two communities using surface drinking water. Both bands (15-17 kD plus 27 kD) were detected in 582 sera (29.9%) from the three communities: 14.1% of sera from Com 1 compared with 32.7% from Com 2 and 31.5% from Com 3. These findings are consistent with a lower risk of exposure to Cryptosporidium from drinking water obtained from deep well sources. However, analysis of results by calendar quarter showed a significant (P < 0.001) increase in the number of Com 3 positive sera (compared with Com 1) following the waterborne outbreak. Without this outbreak-related observation, a significant overall difference in seropositivity would not have been seen. We also observed that in sera from the community affected by the outbreak, the presence on immunoblots of both Cryptosporidium bands appeared to be the best indicator of recent infection. Seroprevalence rates using an ELISA to detect IgG to Giardia were estimated using the same sera. Overall 30.3% (590 of 1,944) of sera were positive by the ELISA. A total of 19.1% of sera from Com 1, 34.7% from Com 2 and 16.0% from Com 3 were seropositive. Rates for both Com 3 and Com 1 did not change significantly over time. In Com 2, rates decreased significantly (P < 0.001) during the last half of the study period (third and fourth calendar quarters). The reasons for the decrease in seroprevalence in Com 2 sera are presently not known. These studies show intriguing associations between seroprevalence, outbreak-related laboratory serologic data, and patterns of parasite contamination of drinking water. Further studies are required to validate the serologic approach to risk assessment of waterborne parasitic infections at a community level.

Flexibility of the major antigenic loop of foot-and-mouth disease virus bound to a Fab fragment of a neutralising antibody: structure and neutralisation

The interaction of foot-and-mouth disease virus (FMDV) serotype C (clone C-S8c1) with a strongly neutralising monoclonal antibody (MAb) 4C4 has been studied by combining data from cryoelectron microscopy and x-ray crystallography. The MAb 4C4 binds to the exposed flexible GH-loop of viral protein 1 (VP1), which appears to retain its flexibility, allowing movement of the bound Fab. This is in striking contrast to MAb SD6, which binds to the same GH-loop of VP1 but exhibits no movement of the bound Fab when observed under identical conditions. However, MAbs 4C4 and SD6 have very similar neutralisation characteristics. The known atomic structure of FMDV C-S8c1 and that of the 4C4 Fab cocrystallised with a synthetic peptide corresponding to the GH-loop of VP1 were fitted to the cryoelectron microscope density map. The best fit of the 4C4 Fab is compatible only with monovalent binding of the MAb in agreement with the neutralisation data on 4C4 MAbs, Fab2s, and Fabs. The position of the bound GH-loop is related to other known positions of this loop by a hinge rotation about the base of the loop. The 4C4 Fab appears to interact almost exclusively with the G-H loop of VP1, making no other contacts with the viral capsid.

An alternative medicine study of herbal effects on the penetration of zona-free hamster oocytes and the integrity of sperm deoxyribonucleic acid

OBJECTIVE

To analyze the effects of certain herbs on sperm DNA and on the fertilization process.

DESIGN

Prospective comparative study.

SETTING

Clinical and academic research environment.

PATIENT(S)

Donor sperm specimens.

INTERVENTION(S)

Zona-free hamster oocytes were incubated for 1 hour in saw palmetto (Serenoa repens), echinacea purpura, ginkgo biloba, St. John's wort (Hypericum perforatum), or control medium before sperm-oocyte interaction. The DNA of herb-treated sperm was analyzed with denaturing gradient gel electrophoresis.

MAIN OUTCOME MEASURE(S)

Oocyte penetration and integrity of the sperm BRCAI exon 11 gene.

RESULT(S)

Pretreatment of oocytes with 0.6 mg/mL of St. John's wort resulted in zero penetration. A lower concentration (0.06 mg/mL) had no effect. High concentrations of echinacea and ginkgo also resulted in reduced oocyte penetration. Exposure of sperm to echinacea purpura and St. John's wort resulted in DNA denaturation. In contrast, saw palmetto and ginkgo had no effect. Sperm exposed to 0.6 mg/mL of St. John's wort showed mutation of the BRCA1 exon 11 gene.

CONCLUSION(S)

High concentrations of St. John's wort, echinacea, and ginkgo had adverse effects on oocytes. Saw palmetto had no effect. The data suggested that St. John's wort, ginkgo, and echinacea at high concentrations damage reproductive cells. St. John's wort was mutagenic to sperm cells.

Co-stimulation of human decidual natural killer cells by interleukin-2 and stromal cells

At the late secretory phase of the menstrual cycle and in early pregnancy, the uterine mucosa is infiltrated by large numbers of natural killer (NK) cells with a distinctive phenotype (CD56bright CD16- CD3-) and large granular lymphocyte (LGL) morphology. Circulating CD56bright NK cells generally proliferate in the presence of interleukin-2 (IL-2), but it is clear that cofactors besides IL-2 are required for optimal response. In the bone marrow, this co-stimulating signal is provided by stromal cells. In the present study we observe that uterine CD56+ cells from early pregnancy decidua similarly proliferate vigorously when cultured with decidual stromal cells and a suboptimal dose of IL-2. This response is dependent on cell-cell contact, as no proliferation of decidual NK cells was observed when they were separated from stromal cells by a permeable cyclopore membrane. In addition, we have studied the expression of Bcl-2 by decidual CD56+ cells. Our results show that the microenvironment of the uterus is likely to have a significant influence on the proliferation and survival of uterine CD56+ cells.

Glucose metabolism in vitro of cultured and transplanted mouse pancreatic islets microencapsulated by means of a high-voltage electrostatic field

The aim of this study was to assess the function of mouse pancreatic islets microencapsulated using a high-voltage electrostatic field. Islets were microencapsulated in alginate/poly-L-lysine/alginate (APA) capsules and maintained in tissue culture. Rates of glucose oxidation and insulin release were then assessed. Glucose metabolism was also measured in microencapsulated islets retrieved after transplantation to normal syngeneic mice. The high-voltage electrostatic system made possible the production of uniformly sized microcapsules, which were smaller than those produced by co-axial air-jet systems. Nonencapsulated islets were used as controls. Empty microcapsules or islet-containing microcapsules were transplanted intraperitoneally and retrieved after 2 weeks for assessment of foreign-body reactions and glucose oxidation rates. After 1 day and 2 weeks in tissue culture, both control islets and microencapsulated islets increased their rates of glucose oxidation and insulin release 7- to 10-fold in response to an increase in glucose concentration from 1.7 to 16.7 mmol/l. Both empty and islet-containing microcapsules, retrieved 2 weeks after transplantation, showed high rates of glucose oxidation at both low and high glucose concentrations, suggesting overgrowth with metabolically active fibroblasts. Morphological studies indicated a marked foreign-body reaction on the surface of all transplanted microcapsules. The islets in cultured microcapsules had a normal histological appearance, whereas the islets within transplanted microcapsules showed a range of morphological appearances, from intact islets to cell debris. In conclusion, this study shows that mouse pancreatic islets survive and remain functionally competent for at least 2 weeks in vitro after microencapsulation in APA capsules generated in an electrostatic field. However, a foreign-body reaction with cellular growth on the capsular surface was present after intraperitoneal syngeneic transplantation.

Inhibition of human sperm motility by specific herbs used in alternative medicine

PURPOSE

Our purpose was to analyze sperm motility parameters in the presence of herbs.

METHODS

Washed sperm were incubated in either saw-palmetto (Serenoa repens, Permixon Sabal serrulatum), echinacea purpura, ginkgo biloba, St. John's wort (Hypericum perforatum), or control medium. Parameters were measured on a Hamilton-Thorn analyzer after 1, 4, 24, and 48 hr at 37 degrees C.

RESULTS

Sperm motility was inhibited at the high concentration (0.6 mg/mL) of St. John's wort. Curvilinear velocities and beat cross frequencies also decreased, but not hyperactivation. High-concentration saw-palmetto, echinacea, or gikgo inhibited motility at 24 and 48 hr.

CONCLUSIONS

A potent inhibition of sperm motility was seen in St. John's wort unrelated to changes in pH. Furthermore, sperm viability was compromised in St. John's wort, suggesting a spermicidal effect. Metabolic changes were observed in saw-palmetto-treated sperm. High-concentration echinacea purpura interfered with sperm enzymes. Ginkgo did not have an antioxidant effect on sperm motility.

The influence of the maternal uterine immune response on placentation in human subjects

The immunological relationship between the mammalian fetus and its mother during pregnancy has been considered similar to that between a transplanted allograft and its recipient ever since Medawar (1953) first proposed the concept of the 'fetus as an allograft' in the early 1950s. Based on this analogy, it has been assumed that implantation of the fetal placenta in the uterus would be controlled similarly by a maternal immune response mediated by T-cells recognizing paternally-derived alloantigens expressed by the placenta. Surprisingly, recent evidence suggests that implantation might involve predominantly a novel allogeneic recognition system based on natural killer cells rather than T-cells (Loke & King, 1995). The cellular and molecular basis of this local immune interaction between the fetal placenta and maternal uterus is now the focus of intense research interest. Since aberrant implantation can cause a variety of clinical problems, including miscarriage, intrauterine growth retardation and pre-eclampsia, an understanding of the immunological mechanism by which this process is controlled could lead to the development of regimens to improve fetal growth and development.

Localization of leukemia inhibitory factor and its receptor in human placenta throughout pregnancy

Mice in which the gene that encodes the receptor (R) for leukemia inhibitory factor (LIF) has been deleted show abnormal growth and development of the placenta. This indicates that LIF plays an important role in placental development. The expression of LIF-R and LIF was examined in human trophoblast and decidua using in situ hybridization and immunocytochemistry. LIF-R mRNA and immunoreactivity was localized in villous and extravillous trophoblast throughout pregnancy, and in endothelial cells of the fetal villi. Strong expression of mRNA encoding LIF was detected in decidual leukocytes, which are abundant at the implantation site. Extravillous trophoblast, which invades the maternal decidua, therefore expresses LIF-R as it moves past decidual leukocytes, which express LIF mRNA. The effect of LIF on cultured human trophoblast was examined in vitro. Recombinant human LIF had no effect on [3H]thymidine incorporation by purified extravillous trophoblast, nor on expression of integrins alpha1, alpha5, or beta1 by isolated trophoblast. These results identify fetal endothelial cells and all cells of the trophoblast lineage as targets for the action of LIF in human placenta. Although its effects on trophoblast are not yet clear, LIF appears to mediate interactions between maternal decidual leukocytes and invading trophoblast. LIF may also play a critical role in controlling angiogenesis in the placental villi, since human fetal endothelial cells express LIF-R, and mice lacking a functional LIF receptor gene show altered vascular development in the placenta.

Characteristics and occurrence of phenolic phytochemicals

Phenolic phytochemicals are the largest category of phytochemicals and the most widely distributed in the plant kingdom. The 3 most important groups of dietary phenolics are flavonoids, phenolic acids, and polyphenols. Flavonoids are the largest group of plant phenols and the most studied. Phenolic acids form a diverse group that includes the widely distributed hydroxybenzoic and hydroxycinnamic acids. Phenolic polymers, commonly known as tannins, are compounds of high molecular weight that are divided into 2 classes: hydrolyzable and condensed tannins. Quantification of food phenolics is just beginning, and preliminary results indicate high variability, even within a given food. Phenolics are biologically active compounds that may possess some disease-preventive properties. Evidence for their ability to prevent cancer or heart disease is preliminary and conflicting. The health benefits of phytochemicals have been reported in the popular press, and the public will come to dietitians for answers to their questions about phytochemicals.

Absence of human papillomavirus E6-E7 transforming genes from HPV 16 and 18 in malignant ovarian carcinoma

Ovarian carcinoma is one of the frequent causes of death from malignancies in the United States. A report excited the scientific community when human papillomavirus were identified in advanced epithelial ovarian carcinoma tissues in 10 of 12 patients. A few studies also identified HPV DNA in ovarian carcinoma tissues. However, several researchers employing polymerase chain reaction techniques and using different oligonucleotide probes did not detect HPV DNA in ovarian carcinoma tissues. The objective was to determine the presence of the E6-E7 genes of HPV types 16 and 18 in archived paraffin-embedded malignant ovarian carcinoma using primers targeting. Archived human malignant ovarian cancer tissues (N = 20 cases) embedded in paraffin blocks were processed, and DNA was extracted and the presence of DNA verified by p53 amplifications. PCR analyses were performed on the extracted DNA together with appropriate controls. The results showed an absence of E6-E7 genes of HPV types 16 and 18 in ovarian carcinoma. However, the presence of other HPV types or gene regions is not ruled out and more studies are needed to resolve the question of HPV involvement in ovarian carcinogenesis.

Investigation of variant Creutzfeldt-Jakob disease and other human prion diseases with tonsil biopsy samples

BACKGROUND

Prion diseases are associated with the accumulation of an abnormal isoform of cellular prion protein (PrPSc), which is the principal constituent of prions. Prions replicate in lymphoreticular tissues before neuroinvasion, suggesting that lymphoreticular biopsy samples may allow early diagnosis by detection of PrPSc. Variant Creutzfeldt-Jakob disease (variant CJD) is difficult to distinguish from common psychiatric disorders in its early stages and definitive diagnosis has relied on neuropathology. We studied lymphoreticular tissues from a necropsy series and assessed tonsillar biopsy samples as a diagnostic investigation for human prion disease.

METHODS

Lymphoreticular tissues (68 tonsils, 64 spleens, and 40 lymph nodes) were obtained at necropsy from patients affected by prion disease and from neurological and normal controls. Tonsil biopsy sampling was done on 20 patients with suspected prion disease. Tissues were analysed by western blot to detect and type PrPSc, by PrP immunohistochemistry, or both.

FINDINGS

All lymphoreticular tissues obtained at necropsy from patients with neuropathologically confirmed variant CJD, but not from patients with other prion diseases or controls, were positive for PrPSc. In addition, PrPSc typing revealed a consistent pattern (designated type 4t) different from that seen in variant CJD brain (type 4) or in brain from other CJD subtypes (types 1-3). Tonsil biopsy tissue was positive in all eight patients with an adequate biopsy sample and whose subsequent course has confirmed, or is highly consistent with, a diagnosis of variant CJD and negative in all patients subsequently confirmed to have other diagnoses.

INTERPRETATION

We found that if, in the appropriate clinical context, a tonsil biopsy sample was positive for PrPSc, variant CJD could be diagnosed, which obviates the need for a brain biopsy sample to be taken. Our results also show that variant CJD has a different pathogenesis to sporadic CJD.

Suicidality in borderline personality disorder

Recent research on the relationship between borderline personality disorder (BPD) and suicidal behavior is reviewed. Risk factors for attempted and completed suicide as well as the effect of the comorbidity of BPD with other Axis I and II disorders are considered. Explanations for suicidality in BPD are discussed. General assessment strategies are offered, along with treatment recommendations. Specifically, research has shown that borderline patients improve in the long-term, decreasing in suicidality, self-destructiveness, and interpersonal maladjustment, if survival is effectively managed during the turbulent years of youth. Clinical lore at times can lead clinicians to disregard the danger of suicide completion among chronically parasuicidal patients, which can prevent effective intervention during suicidal crises and result in unfortunate outcomes.

Asymmetric direduction of 1,2-indanedione to cis (1S,2R) indanediol by Trichosporon cutaneum MY 1506

Cis (1S,2R) indanediol is a potential precursor to (-)-cis (1S,2R)-1-aminoindan-2-ol, a key chiral synthon for a leading HIV protease inhibitor, Crixivan (Indinavir). A potential route to the biosynthesis of this important precursor, the microbial asymmetric direduction of 1,2-indanedione to its corresponding diol, cis (1S,2R) indanediol, was investigated. The screening of 32 yeast strains yielded Trichosporon cutaneum MY 1506 as a suitable biocatalyst. At the 2-l shake-flask scale, 1,2-indanedione (charged at 1.0 g/l) was bioconverted to cis (1S,2R) indanediol at a final bioconversion yield of 99.1% and an enantiomeric excess of >99%. When scaled up in a 23-l bioreactor, T. cutaneum produced 8.4 g of pure cis (1S,2R) indanediol, and the isolated yield of cis (1S,2R) indanediol was 52%. Purification of the scale-up also yielded 0.9 g of the more polar trans (1S,2R) indanediol diastereomer, a minor bioreduction product. Supercritical fluid chromatography analyses of the purified cis (1S,2R) and trans (1S,2S) indanediol demonstrated that the enantiomeric excesses during this bioconversion scale-up were 99% and 26%, respectively.

Aggregation of human sperm at higher temperature is due to hyperactivation

Chemotaxis of sperm cells to chemicals and hormones, such as progesterone, helps us to understand the concept of sperm transport. Here, the hypothesis was that heat increased sperm hyperactive motility, which caused the sperm to aggregate at the higher temperature. The objectives were (1) to determine the concentration of sperm at both halves of an artificial female reproductive tract made from a hermetically sealed cryopreservation straw filled with culture medium and placed with each end at different temperatures, and (2) to analyze the motility or kinematic parameters and hyperactivation of sperm found at the different temperatures. Cryopreserved-thawed human donor sperm (N = 6) were pooled and processed through 2-layer colloid solution. Analyses of the motile sperm were carried out and the washed sperm were homogeneously mixed and pipetted into several 0.5-mL French cryopreservation straws and heat-sealed. The control substance, consisting of acid-treated sperm, was also placed in several straws. The plastic straws of sperm were placed half at 23 degrees C and half was at either 37 or 40 degrees C. After 4 h, sperm at different sections of the straws were analyzed using the Hamilton Thorn motility analyzer (HTM-C). After 4 h of incubation, the concentration of sperm was doubled at the 40 degrees C heated half of the straw when compared with the other half of the straw at 23 degrees C. There were no differences in sperm concentration in the straw kept half at 37 degrees C and half at 23 degrees C. There were significantly higher percent motility, mean average path velocity, straight line velocity, lateral head displacement, and percent hyperactivation in sperm at the 40 degrees C temperature. The aggregation of sperm at the higher temperature of 40 degrees C may be due to enhanced motility, increased sperm velocities, and a 10-fold increase in hyperactivation at that temperature. The 37 degrees C temperature was not sufficient to attract sperm. Sperm cells migrating into the higher temperature site of ovulation begin nonprogressive hyperactivation movement, which is the physiological "brake" to detain the sperm at the site of ovulation.

Use of mass spectrometric methods for protein identification in receptor research

In recent years, mass spectrometry has become the method of choice for identifying small amounts of gel separated proteins. Using high mass accuracy peptide mass mapping followed if necessary by nanoelectrospray sequencing, most mammalian proteins can now be identified quickly and sensitively either in amino acid or in EST sequence databases. These methods are illustrated here using an ongoing project in the author's laboratory, a mass spectrometric screen for new mouse brain receptors and their interaction partners.

Molecular studies of trophoblast HLA-G: polymorphism, isoforms, imprinting and expression in preimplantation embryo

There is considerable interest in human HLA-G arising from the observation that it is expressed selectively on the surface of extravillous trophoblast, the fetal cell population directly in contact with the mother. We investigated several aspects of the molecular biology of this unusual molecule. Limited polymorphism at the nucleotide level, and even more restricted variation at the amino acid level, was found in our Caucasian population. A further unusual aspect of HLA-G is the occurrence of alternatively spliced mRNAs. Spliced messages that could give rise to either membrane-bound or soluble proteins have been reported and six of these alternative forms were detected in all first trimester and term placentae, highly purified villous and extravillous trophoblast and the cell lines, JEG-3 and 221-G. An additional novel splice variant involving loss of part of the 3'-untranslated region was observed with two alleles. Using a sensitive RNase protection assay higher levels of the membrane-bound RNAs as compared to the soluble forms were detected in first trimester and term placentae as well as in JEG-3. Contrary to previous findings our term samples taken from the maternal aspect showed higher levels of both mRNA species when compared to first trimester placenta. The question of imprinting was addressed through the detection of heterozygotes both in placental tissue and, more tellingly, in the purified trophoblast cells. There was no evidence of imprinting. In addition we did not find mRNA for HLA-G in human two to eight-cell embryos or in blastocyst or in sperm samples.

Apoptosis in the early human placental bed and its discrimination from necrosis using the in-situ DNA ligation technique

Extensive areas of necrosis are present in the early human placental bed. Our aim was to determine whether apoptosis is also a feature. A method was therefore required to differentiate unequivocally necrosis and apoptosis. Initially, terminal deoxynucleotide transferase-mediated dUTP nick-end labelling was used to visualize apoptotic cells. However, non-specific labelling, probably due to free DNA released by necrotic cells, was excessive; thus, in-situ DNA ligation was employed. In this technique, two DNA fragments with single-base 3' overhangs and blunt-ends were labelled with a fluorochrome and then ligated to the DNA breaks on the sections. Immunolabelling for cytokeratin or leukocyte common antigen was performed to determine the phenotype of apoptotic cells identified by the in-situ DNA ligation technique. A proportion of the dying cells was confirmed to be trophoblasts. No co-localization with leukocyte common antigen was found in this region, suggesting that maternal macrophages and natural killer cells (CD56+) were not dying by apoptosis in significant numbers. In conclusion, in-situ DNA ligation in association with immunocytochemistry can readily distinguish apoptosis from necrosis in the placental bed. The results suggest that a proportion of invading trophoblast cells are eliminated by apoptosis in early pregnancy.

Comparative activity of quinupristin/dalfopristin and RPR 106972 and the effect of medium on in-vitro test results

Quinupristin/dalfopristin and RPR 106972 were active in vitro against a wide range of aerobic Gram-positive organisms including Enterococcus faecium. However, most isolates of Enterococcus faecalis were resistant or of intermediate sensitivity. Against Staphylococcus aureus quinupristin/dalfopristin was more active but for all other species the range of activity of the two drugs was the same or RPR 106972 was more active. RPR 106972 was also more active against the respiratory pathogens Haemophilus influenzae and Moraxella catarrhalis. Quinupristin/dalfopristin MICs for isolates of H. influenzae (1-8 mg/L) clustered around the breakpoint. There were differences in the quality of growth, but little difference in MICs or zone diameters was obtained on three different media: Mueller-Hinton (MHA), Iso-Sensitest (ISA), and Diagnostic Sensitivity Test (DST) agars. The addition of blood to the medium increased MICs 2- to 4-fold, with MHA showing the greatest increase, and reduced zone diameters around quinupristin/dalfopristin discs by 3-4 mm, with the greatest effect on ISA.

Assessment of archived paraffin-embedded cervical condyloma tissues for mycoplasma-conserved DNA using sensitive PCR-ELISA

Clinically, it is important to detect mycoplasmas because these organisms have been implicated in gastric and ovarian cancer, pneumonia, postabortal fever, pelvic inflammatory disease, pyelonephritis, endometritis, urethritis, perinatal mortality, arthritis, spontaneous abortion, infertility and interference with sperm development and they act as cofactors catalyzing the HIV disease state. Recently, the combined polymerase chain reaction and enzyme-linked immunosorbent assay method targeting the consensus DNA of over 15 species of mycoplasmas was shown to be superior for the detection of mycoplasmas. The objective was to determine if there was an association between mycoplasmas and cervical neoplasia. Cervical tissues, histopathologically categorized by cervical intraepithelial neoplasia (CIN) grade, flat or exophytic, and acanthosis or koilocytotic, were used. The results showed that mycoplasmas DNA were present in 21.4% of the condyloma tissues and in 33.3% of condyloma tissues with CIN. In contrast, mycoplasmas DNA were not detected when there were no CIN. The presence or absence of human papillomavirus (HPV) did not make a difference. Mycoplasmas DNA were present in 40.0 and 12.5% of the exophytic and flat condylomas, respectively. A higher percentage of cervical tissues graded with slight koilocytosis had (P = 0.05) mycoplasmas DNA compared with tissues graded with moderate koilocytosis. The detection of mycoplasmas DNA in archived cervical condyloma tissues with CIN corroborated previous reports of an association between mycoplasmas and CIN. However, the association between mycoplasmas and the presence of HPV could not be made in this study.

An unusual case of primary leptomeningeal marginal zone B-cell lymphoma

Primary leptomeningeal lymphomas are rare, and usually follow a rapid clinical course with early systemic involvement. A 60-year-old woman presented with a 3-year history of worsening seizures and memory loss. Neuroimaging showed widespread meningeal calcification. After extensive investigations a meningeal biopsy revealed a low-grade B-cell lymphoma categorized as an extranodal marginal zone B-cell lymphoma, attributed to the same histological group as the MALT (mucosa-associated lymphoid tissue) lymphomas described in the stomach, thyroid, salivary glands and orbit. There was no evidence of systemic involvement. The extensive meningeal calcification would appear to be a novel finding in primary leptomeningeal lymphoma whereas the unusually long clinical history in this case is possibly related to the particular histological type of low-grade B-cell lymphoma.

Incidence of antibiotic resistance in blood and urine isolates from hospitalized patients. Report from a European collaborative study. European Study Group on Antibiotic Resistance (ESGAR)

During 1992-93, 2544 isolates from blood cultures, comprising 52% gram-negative bacilli, 24% Staphylococcus aureus, 15% other staphylococci, 7% Enterococcus faecalis and 2% E. faecium, were consecutively collected and identified in 30 laboratories in 21 European countries. In addition 2512 urine isolates, comprising 82% gram-negative bacilli, 3% S. aureus, 4% other staphylococci and 11% enterococci were collected. The bacteria were sent to 3 laboratories for susceptibility testing by the microdilution method in Mueller-Hinton broth. The MICs of penicillins and aztreonam for all susceptible gram-negative bacilli were 0.25-8 mg/l, penems 0.032-2 mg/l, cefotaxime, ceftazidime and cefpirome or cefepime 0.032-0.25 mg/l, gentamicin, tobramycin and netilmicin 0.125-2 mg/l, amikacin 0.5-4 mg/l, ciprofloxacin 0.016-1 mg/l, trimethoprim 0.25-1 mg/l and tetracycline 1-2 mg/l. For susceptible staphylococci the MICs of erythromycin were 0.25-0.5 mg/l, clindamycin 0.125-0.25 mg/l, methicillin 2-8 mg/l, vancomycin and trimethoprim 1-4 mg/l, ciprofloxacin 0.25-1 mg/l, gentamicin and tobramycin 0.25-1 mg/l. For the enterococci the MICs of ampicillin and vancomycin were 2-4 mg/l and of imipenem, teicoplanin and trimethoprim 0.5-1 mg/l. The antibiotic resistance rates varied between laboratories, being lower in northern Europe, except for the penems, cefpirome and cefepime, which showed uniformly lower resistance rates. Compared to the earlier European studies the resistance rates to beta-lactam antibiotics among the gram-negatives have not changed except with an increase to cefotaxime and ceftazidime in central Europe. Resistance to aminoglycosides had also increased in central Europe from 7-8% to 20-21%, but decreased in southern Europe from 22-24% to 13-14% among the blood isolates and from 12-28% to 6-7% among the urine isolates. There was an increase in resistance to ciprofloxacin and gentamicin in staphylococci from southern Europe. The prevalence of MRSA was significant in central and southern Europe. It is of importance that collaborative national and international studies on the incidence of antibiotic resistance are being performed on a repetitive basis.

Nalmefene causes greater hypothalamic-pituitary-adrenal axis activation than naloxone in normal volunteers: implications for the treatment of alcoholism

Among other actions, opioid antagonists modulate the control endogenous opioids exert on the hypothalamic-pituitary-adrenal (HPA) axis. Naloxone, nalmefene, and naltrexone are the opioid antagonists approved for use in man and are primarily mu-opioid selective. Naltrexone and nalmefene have been demonstrated to be useful in the treatment of alcoholism. Compared with naloxone, nalmefene has a longer half-life, is more potent at the mu-receptor, and has a higher affinity for kappa- and delta-opioid receptors. We conducted an inpatient study comparing the effects of 10 and 30 mg doses of intravenous naloxone and nalmefene in normal, nonsubstance nor alcohol-abusing, volunteers. Significant increases in ACTH and cortisol were observed after both antagonists, without an apparent dose-response relationship; however, both doses of nalmefene resulted in greater HPA axis activation than either dose of naloxone (ACTH: p <0.005). These results indicate that kappa- and delta-opioids may play important roles in the regulation of the HPA axis; nalmefene may be useful as both a probe to explore the HPA axis physiology and as a pharmacotherapeutic agent.

Free alpha-subunit and intact TSH secretion in vitro are closely associated in human somatotroph adenomas

OBJECTIVE

GH-secreting pituitary adenomas frequently co-secrete prolactin and glycoprotein hormone alpha-subunit (alphaSU), but expression of additional hormones is considered unusual. The aim of this study was to establish the frequency with which acromegalic tumours secrete intact glycoprotein hormones LH, FSH and TSH, in comparison with other types of pituitary adenoma.

DESIGN AND METHODS

Pituitary tumours were studied by cell culture, measuring the basal secretion of anterior pituitary hormones in vitro. Light microscopy was used to exclude tumours where normal pituitary tissue was present, and immunocytochemistry was employed to confirm the clinical diagnosis and for comparison with tissue culture data.

RESULTS

TSH secretion was observed in vitro in 15/23 somatotroph adenomas, but from only 1/8 lactotroph, 4/29 null cell, 2/12 gonadotroph and 1/10 corticotroph adenomas; moreover, somatotroph adenomas secreted the largest amounts of TSH (P < 0.(001). Somatotroph adenomas also secreted LH (7/23) and FSH (2/23) but less frequently than gonadotroph adenomas. Immunocytochemistry demonstrated glycoprotein expression in somatotroph adenomas (LHbeta: 13%, FSHbeta: 26%, TSHbeta: 30%, alphaSU: 46%) more frequently than in lactotroph, corticotroph and null cell adenomas. A strong correlation was found between alphaSU secretion and TSH secretion in somatotroph adenomas (rho= 0.683, P < 0.001.

CONCLUSIONS

TSHbeta is frequently expressed by somatotroph adenomas, often associated with alphaSU expression. Both GH and TSHbeta are dependent on the transcription factor, Pit-1, which is frequently expressed in somatotroph adenomas, although the expression of alphaSU requires an alternative explanation. Increased expression of alphaSU compared with TSHbeta may account for the secretion of free alphaSU by somatotroph adenomas.

Positive intravenous line tip cultures as predictors of bacteraemia

Intravenous line tip cultures provide valuable information when taken in conjunction with blood culture, but in practice are often performed in isolation. This retrospective study has evaluated: (1) the frequency of isolated line tip culture; and (2) whether the species of microorganism isolated from line tip culture, using the Maki semi-quantitative culture method, is predictive of bacteraemia. Of 2753 line tip culture episodes in 1659 patients between May 1993 and August 1995, 2230 were performed in isolation (81%). Evaluation of 792 positive line tip culture episodes in 654 patients where blood cultures were performed in the period from 48 h before, to 24 h after tip culture, identified 825 line tip isolates. Of these, 194 were associated with a blood culture positive for the same species. The rate of positive blood culture, according to species, ranged from 10-72%. The highest rate was seen for methicillin-susceptible Staphylococcus aureus where 70 of 97 line tip episodes (72%) were associated with positive blood culture. This compared with a rate of 17% for coagulase-negative staphylococci (P < 0.0001). Patients with line tip cultures positive for S. aureus should be considered to be at high risk of bacteraemia.