Delta-opioid receptor agonists inhibit neuromuscular transmission in human colon

The present study was undertaken to investigate the possible role of delta-opioid receptors in the neuroregulation of human colonic motility by using a superfusion model. Spontaneous mechanical activity and responses to electrical transmural nerve stimulation of both longitudinal and circular muscle strips from the human sigmoid colon were studied. Exogenously added delta-opioid receptor agonists did not modify spontaneous contractile activities of either type of strip. Nerve stimulation induced a triphasic response composed of an initial contraction followed by a relaxation and an off-contraction. This response was mediated by cholinergic excitatory nerves and non-adrenergic, non-cholinergic excitatory and inhibitory nerves. [Met5]Enkephalin and the synthetic delta-opioid receptor agonist [D-Pen2,D-Pen5]enkephalin (DPDPE) significantly decreased the amplitude of the initial contraction and of the off-contraction. The effects of both delta-opioid receptor agonists were reduced in the presence of either the delta-opioid receptor antagonist, ICI 174864, or another delta-opioid receptor antagonist, naltrindole. ICI 174864 prevented neither the effects of a natural kappa-opioid receptor agonist, dynorphin-(1-13) nor those of the mu-opioid receptor agonist, PL017. Therefore, these data suggest that delta-opioid receptors might be involved in the neuroregulation of smooth muscle of human colon and may mediate inhibition of cholinergic and non-cholinergic excitatory transmission within the myenteric plexus.

Control of red cell function of late chick embryos: role of extracellular ATP/AMP and egg size

Hypoxia is the alleged stimulus for initiation of increase of carbonic anhydrase II (CAII) and 2,3-diphosphoglycerate (2,3-DPG) synthesis of red blood cells from late chick embryos. The PO2-dependent regulation of red cell metabolism is mediated by unknown humoral factors [Million et al., Am. J. Physiol. 261 (Regulatory Integrative Comp. Physiol. 30): R1188-R1196, 1991]. In the present investigation we have analyzed whether interindividual differences in egg size (which result in different surface area-to-mass ratios) affect the timing of initiation of 2,3-DPG and CAII synthesis in late chick embryos. We also investigated the effect of extracellular adenine nucleotides on red cell organic phosphate pattern and O2 affinity to test whether the inhibitory effect of normal or elevated PO2 on 2,3-DPG synthesis and the concomitant increase of ATP (and O2 half-saturation pressure) can be mimicked by these agents. The results show that differences in egg size affect the timing of CAII and 2,3-DPG synthesis, indicating that PO2-dependent regulation of red cell function allows adjustment to the properties of the individual egg. We also found that extracellular ATP, which is rapidly degraded to AMP by red cell ectoenzymes, can alter the red cell phosphate pattern and O2 affinity, i.e., significantly increase red cell ATP, decrease red cell 2,3-DPG and O2 affinity, and thus mimic the effect of normoxia and hyperoxia. These findings suggest that extracellular adenine nucleotides may be involved in the PO2-dependent regulation of embryonic red cell metabolism.

Development of resistance to macrolide antibiotics in an AIDS patient treated with clarithromycin for Campylobacter jejuni diarrhea

In an AIDS patient with diarrhea, identical isolates of Campylobacter jejuni susceptible and, later, resistant to macrolide antibiotics were isolated from feces before and after treatment with clarithromycin. Results of rRNA gene restriction analysis and serotyping suggest that development of resistance rather than simultaneous infection with a susceptible and a resistant strain was responsible for this phenomenon. This is the first report of in vivo development of resistance by Campylobacter jejuni in a patient treated with a macrolide for Campylobacter jejuni infection.

Prevalence and significance of anticardiolipin antibodies in Crohn's disease

Crohn's disease is a chronic inflammatory bowel syndrome in which thrombotic complications occur in the active phase. Phospholipid-binding antibodies such as anticardiolipin antibodies and lupus anticoagulants have been shown to be associated with thrombosis. Their presence has been assessed in a group of 50 patients with Crohn's disease among whom 44 had active disease. The overall prevalence of anticardiolipin antibodies was about 22%, while none of these patients had lupus anticoagulant. Anticardiolipin antibodies have been observed in both active and quiescent CD and their presence does not seem to be related to the site of CD lesions. The presence of phospholipid-binding antibodies could be a sign of vascular alterations that are potentially thrombogenic per se, and their predictive value with respect to the specific inflammatory syndrome of Crohn's disease is discussed.

Chloride and bicarbonate transport in chick embryonic red blood cells

1. Unidirectional efflux of 36Cl- and H14CO3- from erythrocytes of 4- to 16-day-old chick embryos was measured under steady-state conditions at 37 degrees C and pH 7.7. The efflux rates were high, > 3 s-1, and were, therefore, measured by means of the continuous flow tube method. 2. At day 4 of development the range of permeability coefficients for bicarbonate and chloride (PHCO3 and PCl was 1-30 x 10(-4) cm s-1, with average values of respectively 10 x 10(-4) and 8 x 10(-4) cm s-1. However, the results can be divided into two groups, one with PHCO3 and PCl above 12 x 10(-4) cm s-1, and one with values below 5 x 10(-4) cm s-1. The same range of values was also obtained for day 6 erythrocytes, but the overlap is more conspicuous. At day 16, PHCO3 and PCl were respectively 9 x 10(-4) and 6 x 10(-4) cm s-1 (37 degrees C, pH 7.7). In adult chicken red blood cells PHCO3 and PCl were respectively 7 x 10(-4) and 4 x 10(-4) cm s-1, and in human red blood cells the respective values were 5.6 x 10(-4) and 4 x 10(-4) cm s-1. 3. Chloride self-exchange, measured at 0 degrees C, was almost completely inhibited by addition of 1 mM 4,4'-diisothiocyanostilbene-2,2'-disulphonate (DIDS) at both days 6 and 16 of embryonic development, supporting the finding that the embryonic chick erythrocytes also have a transmembrane anion exchanger similar to that of other red cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Systemic treatment of ectopic pregnancies with single-dose methotrexate

STUDY OBJECTIVE

To evaluate the success rate, side effects, reproductive outcome, and possible pitfalls of systemic low-dose methotrexate (MTX) for treatment of ectopic pregnancy (EP).

DESIGN

Longitudinal, nonrandomized trial Setting. Department of Obstetrics and Gynaecology at a teaching hospital in Germany.

PATIENTS AND INTERVENTIONS

Forty women with EP were treated with a single dose of MTX 20 to 40 mg intravenously. The highest pretreatment human chorionic gonadotropin (hCG) titer was 21,100 mIU/ml.

MEASUREMENTS AND MAIN RESULTS

Thirty-seven patients (92.5%) were treated successfully. Thirty-four (85%) received a single dose of MTX. Six (15%) required a second dose about a week later. Three patients (7. 5%) required surgical intervention. Serum MTX levels decreased below 0.1 micromol/L (45.4 microg/L) within 24 hours. In 53.8% of women hCG levels decreased directly after treatment; in 46.2% levels increased within the first 5 days after treatment.

CONCLUSIONS

In selected patients, systemic low-dose MTX is an effective way to treat EP, and has no demonstrable side effects.

[Pregnancy following sterilization and endometrium resection]

We report on the successful outcome of a pregnancy after bipolar electrocoagulation of Fallopian tubes for sterilisation followed by electroresection of the endometrium for menorrhagia. Reasons for sterilisation failure are discussed with special attention to benefits and risks of endometrial ablation as a new "minimally invasive" therapy for menstrual disorders. We propose guidelines for patients' counselling and preoperative consent.

Comparing regions of the Epstein-Barr virus ZEBRA protein which function as transcriptional activating sequences in Saccharomyces cerevisiae and in B cells

The ZEBRA protein activates expression of Epstein-Barr virus early-lytic-cycle genes in human B lymphocytes. Here it is shown that ZEBRA also behaves as a sequence-specific transcriptional activator in Saccharomyces cerevisiae. Deletional mutagenesis defined three regions of ZEBRA that participate in activation in S. cerevisiae. These regions are designated YI (amino acids [aa] 1 to 25), YII (aa 51 to 102), and YIII (aa 228 to 245). Two of the three regions of the native ZEBRA protein act together to mediate activation when assayed on ZEBRA binding sites. However, when fused to the DNA binding domain of GAL4 and assayed on GAL4 binding sites, regions YII and YIII were each sufficient to confer activation in S. cerevisiae. Regions of ZEBRA which affected activation in S. cerevisiae were also required in human B lymphocytes. The amino-terminal region of ZEBRA (aa 1 to 98) was required for activation both in S. cerevisiae and in human B cells; deletion of the carboxy-terminal 18 aa also significantly reduced activation in both cell types. Thus, the behavior of ZEBRA in human B cells and S. cerevisiae suggests that the protein contains universal activation motifs that interact with conserved components of the transcription machinery. However, certain deletion mutants of ZEBRA containing mutations in the N-terminal region exhibited discordant behaviors in S. cerevisiae and in B cells. For example, deletion of ZEBRA aa 26 to 51 impaired activation to a great extent in B cells but had little or no effect in S. cerevisiae. The discordant mutants may reflect interactions with a variable domain of a conserved component or unique interactions with specialized components of the basal transcription apparatus in different cells.

Changing Epstein-Barr viral ZEBRA protein into a more powerful activator enhances its capacity to disrupt latency

The Epstein-Barr viral transcriptional activator ZEBRA induces expression of viral early lytic genes when introduced into cells bearing latent Epstein-Barr virus. We show here that a ZEBRA-herpes simplex viral protein 16 (VP16) fusion protein induces early viral lytic gene expression in Epstein-Barr virus-containing cells more efficiently than does wild-type ZEBRA. The fusion protein is also a more powerful transcriptional activator in these cells, as assayed with reporter constructs. Our experiments also suggest that ZEBRA manifests a function required for full activity on certain natural promoters but not on promoters bearing oligomerized ZEBRA binding sites; this function cannot be provided by VP16.

Control of cell pH in immature primitive red cells from chick embryo

1. The intracellular pH in primitive red cells from 4 day chick embryos was measured with the digitonin null-point method and the fluorescent indicator SNARF-1. At physiological pHe of 8.0 red cell pH is 7.39 at day 4. 2. The calculated proton equilibrium potential of -38 mV is in good agreement with previous measurements of Em (Engelke et al., 1988) and supports the conclusion that the Em is dominated by a proton conductance. 3. The sodium-proton exchanger is present in primitive red cells but quiescent under physiological conditions. 4. The results indicate that the bicarbonate-chloride exchange via Band 3 protein is impaired.

Intestinal carcinoid tumor and myotonic dystrophy. A new association?

The occurrence of multiple carcinoid tumors of the small bowel with liver metastases is reported in a patient with a previous myotonic dystrophy. In addition to the association of myotonic dystrophy with multiple endocrine adenomatosis type 2A, hyperparathyroidism, and neurofibromatosis, this case report gives further evidence for the propensity of such patients to develop neuroendocrine tumors.

[HIV-associated malignant lymphomas]

In a retrospective analysis of data from 35 cases with malignant lymphoma from a cohort of 2017 HIV-infected patients, the stage of HIV-disease, the CD4 counts at the time of diagnosis, and the use of antineoplastic agents or radiotherapy were correlated with outcome. 6 patients had Hodgkin's lymphoma (HL) and 29 non-Hodgkin-lymphoma (NHL). 11 of these lymphomas were classified according to the international working formulation (IWF) as high grade (H, I and J, respectively) and 8 as intermediate grade (G). 10 could not be classified. 22 patients with NHL had stage IV disease according to the Ann Arbor classification, all of whom had manifestations at extranodular sites. 23 patients with NHL were treated with multiagent chemotherapy (18 with m-BACOD or CHOP, 5 patients with various other regimens) and four of them had additional radiotherapy. One patient received radiotherapy only. Two of 24 treated patients showed complete and five a partial response. Median survival of patients without treatment (all of them in poor general condition at the time of diagnosis) was 1.8 months and treated patients survived a median of 5 months. The pretreatment CD4 count was the most important predictor of survival. Patients with prior Aids-diagnosis showed a tendency towards shorter survival. The observed remission rate indicates that HL in HIV-infected patients is better treatable than HIV-associated NHL. However, the overall outcome of HL in our patients was clearly less favorable compared to the course of HL usually seen in patients without HIV infection. The proportion of patients with HL among all patients with malignant lymphoma and HIV disease was unexpectedly larger in our cohort compared to others. Therefore, a possible association of HL and HIV infection, as addressed by several other authors, needs further clarification.

Trophoblast tissue culture of human intrauterine and ectopic pregnancies and treatment with methotrexate

The application of drugs for conservative treatment of patients with ectopic pregnancy has been used worldwide for several years. In-vitro studies, however, are very few. We therefore examined the effects of methotrexate on trophoblast tissue cultures derived from intrauterine and ectopic pregnancies. Methotrexate was administered either 12 h or 6 days after initiation of the culture. Human chorionic gonadotrophin (HCG) levels were measured in the culture medium. All cultures showed secretion of HCG within the first 16 days. Methotrexate concentrations less than 3.8 x 10(-4) mol/l had no effect on HCG secretion. Cultures of ectopic pregnancies required a concentration about 10x higher to induce an equivalent reduction of HCG levels compared to intrauterine pregnancies. A few intrauterine and ectopic pregnancies showed no reduction of HCG values after treatment. These results suggest that data obtained from studies on intrauterine pregnancies may not be transferable to ectopic pregnancies in all instances. In some regimens approximately 8 days are required before the effect becomes measurable. In combination with our clinical data, we therefore recommend not to repeat a methotrexate dose too early in treatment of patients with ectopic pregnancies. The possibility that non-responding patients could exist should be kept in mind.

Oxygen pressure-dependent control of carbonic anhydrase synthesis in chick embryonic erythrocytes

During chick embryonic development carbonic anhydrase (CA) expression of erythrocytes is kept at a very low level until the last week of incubation (i.e., up to day 14). We have previously obtained evidence that hypoxia is the physiological stimulus for rapid onset of CA synthesis before hatching. Looking for putative signals we have carried out in vitro incubations of embryonic erythrocytes, screening a large number of hormones and second messengers, which were all ineffective, with the exception of the A1 agonist N6-phenylisopropyladenosine (adenosine had no effect). However, incubation with embryonic plasma (10%) from embryos greater than 6 days caused a 10-fold increase of the CA activity during 24 h. This increase was not observed when the incubation was carried out with the addition of actinomycin D, cycloheximide, aluminum fluoride, pertussis toxin, or heat-inactivated plasma. Mammalian plasma had no effect on CA activity. Filtration experiments show that the molecular mass of the factor is less than 2,000 Da. We conclude that embryonic plasma contains a heat-labile factor which stimulates CA synthesis via activation of transcription and whose receptor is coupled to a pertussis toxin-sensitive G protein. In vivo the action of the plasma factor is suppressed as long as blood Po2 is high, suggesting the presence of an inhibitor molecule whose synthesis is controlled by the Po2.

Prospective comparison of videopelviscopy with laparotomy for ectopic pregnancy

OBJECTIVE

To compare operative laparoscopy with laparotomy for the management of ectopic pregnancy in haemodynamically stable women.

DESIGN

Non-randomized prospective cohort study, treatment allocation depending on the surgical preference and experience of the on-call medical team.

SETTING

Provincial undergraduate teaching hospital.

SUBJECTS

87 consecutive and unselected haemodynamically stable women treated for ectopic pregnancy between 1 March 1988 and 31 August 1989.

INTERVENTIONS

Salpingotomy, salpingectomy, salpingo-oophorectomy or simple extraction of the ectopic pregnancy depending on its site, size and nature performed under laparoscopic control or laparotomy.

MAIN OUTCOME MEASURES

Operative outcome, duration of surgery, intra- and post-operative complications, post-operative hospital stay, return to normal domestic activities, return to work, changes in plasma beta-hCG concentrations, health and social service costs.

RESULTS

60 women were treated by videopelviscopy on 65 occasions and the other 27 were treated by laparotomy. The two groups were similar for age, parity and gestation at presentation. Of the 65 operative laparoscopies 61 (94%) were successful and all 27 laparotomies were completed uneventfully. Whereas the operating time was similar in the two groups, 55.3 and 51.1 min for videopelviscopy and laparotomy respectively, operative laparoscopy was associated with significantly shorter post-operative hospital stay (1.7 vs 5.2 days), faster return to domestic activities (1.5 vs 3.3 weeks) and work (2.5 vs 5.7 weeks) (P less than 0.001 for all). In economic terms, successful videopelviscopy was associated with a reduction in hospital accommodation costs by 69% (248 pounds vs 808 pounds), drug costs by 52% (8.38 pounds vs 17.57 pounds) and statutory sickness payment by 51% (130.25 pounds vs 266.51 pounds), that is an overall saving to the health and social services of 701.47 pounds or 50% per ectopic pregnancy (P less than 0.001).

CONCLUSIONS

Operative laparoscopy can be used to successfully treat most cases of extrauterine pregnancy with advantages over laparoscopy in terms of reduced hospitalization, faster recovery and lower health service costs.

Combined treatment with zidovudine and lymphoblast interferon-alpha in patients with HIV-related Kaposi's sarcoma

A combination of oral zidovudine (250 mg twice daily) and subcutaneous interferon-alpha (10 x 10(6) units daily) was evaluated for clinical, antiretroviral, and immunological efficacy and for side effects in 17 patients with AIDS-related Kaposi's sarcoma. Fifteen patients were evaluable. During the study period of 12 weeks, tumor responses were complete in two patients and partial in two patients (27% major response rate). Minimal responses were seen in two patients (40% overall response rate). An anti-HIV effect (reduction of serum p24 antigen by 70% or more) was observed in seven of ten evaluable patients who were initially antigenemic. CD4 lymphocyte counts remained unchanged. In six patients who had either a tumor response or a marked decline of HIV antigenemia, the treatment was continued between 12 and 59 weeks beyond the study period. Two of four patients with tumor regression at 12 weeks had an additional tumor response in this period despite prior dose reduction of interferon due to toxicity. Late progression of KS was eventually observed in four of six patients on prolonged treatment. The responsiveness of Kaposi's sarcoma seen in this study in patients with low CD4 counts and prior constitutional symptoms (fever, weight loss) was unexpected and needs further confirmation by larger patient groups. Dose-limiting toxicities were bone marrow depression (severe anemia in four and neutropenia with anemia in two patients), subjective adverse experiences (fever, fatigue, myalgia; four patients) and both (two patients).(ABSTRACT TRUNCATED AT 250 WORDS)