Chlamydia pneumoniae serology: interlaboratory variation in microimmunofluorescence assay results

The lack of standardization in chlamydia serology has made interpretation of published data difficult. This study was initiated to determine the extent of interlaboratory variation of microimmunofluorescence (MIF) test results for the serodiagnosis of Chlamydia pneumoniae infections. Identical panels of 22 sera were sent to 14 laboratories in eight countries for the determination of IgG and IgM antibodies by MIF. Although there was extensive variation in the numeric titer values, the overall percentage agreement with the reference standard titers from the University of Washington was 80%. For results by serodiagnostic category, the best agreement was for four-fold rise in IgG titers, while the lowest agreement was for negative or low IgG titers. Agreement for IgM titers was 50%-95%. Four laboratories failed to discern false-positive IgM titers possibly because of the presence of rheumatoid factor. Further studies are underway to determine the source of interlaboratory variation for the MIF test.

Combined seropositivity for H. pylori and C. pneumoniae is associated with age, obesity and social factors

BACKGROUND

Manifestations of cardiovascular disease (CVD) have been associated with chronic infection by Helicobacter pylori and Chlamydia pneumoniae both in cross-sectional and in prospective follow-up cohort studies. This association may be partly due to an increase in metabolic risk factors for CVD, secondary to low-grade inflammation caused by infections.

OBJECTIVE

To investigate for subjects classified according to serology titres for infection with C. pneumoniae and H. pylori associations between seropositivity and the degree of obesity and fasting insulin levels, as well as social factors.

METHODS

Using methods based on those in earlier investigations of hypertensive patients in the Dalby primary-health-care district, southern Sweden, we investigated frozen samples from serum of 310 middle-aged treated hypertensives and 288 age-matched and sex-matched normotensive controls from a defined population. The baseline examination included the measurement of weight, height and blood pressure as a mean of two office readings with the subject supine. The body mass index (BMI) was calculated as kg/m2. Fasting blood samples were drawn for measurements of levels of serum lipids, blood glucose, plasma insulin and serum lipids, including total cholesterol and triglycerides. The serology titres for H. pylori were determined by an enzyme-linked immunosorbent assay. The titres for C. pneumoniae were determined by a micro-immunofluorescence method. Self-reported factors concerning social and lifestyle backgrounds were recorded.

RESULTS

The group (n = 245) of subjects with combined positive serology for H. pylori and C. pneumoniae differed from the group without any positive serology (n = 57) in age (61.6 versus 57.4 years, P < 0.05) and BMI (27.3 versus 25.8 kg/m2, P < 0.05). The seropositive group also differed in terms of fasting levels of insulin (12.7 versus 11.6 pmol/l, P < 0.05), but this difference did not remain significant after adjustment for age and BMI. We detected no intergroup difference in blood pressure and levels of glucose and lipids. Members of the group with combined seropositivity reported having a lower social-class position (educational level) than that of members of the seronegative group.

CONCLUSION

Subjects with combined positive serology for H. pylori and C. pneumoniae are characterized by greater age, lower social class and higher BMI, as well as higher fasting levels of insulin than those of seronegative subjects. Obesity might be a marker not only for lower social class but also for greater than normal susceptibility to such infections.

PAC1 receptor-deficient mice display impaired insulinotropic response to glucose and reduced glucose tolerance

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a ubiquitous neuropeptide of the vasoactive intestinal peptide (VIP) family that potentiates glucose-stimulated insulin secretion. Pancreatic beta cells express two PACAP receptor subtypes, a PACAP-preferring (PAC1) and a VIP-shared (VPAC2) receptor. We have applied a gene targeting approach to create a mouse lacking the PAC1 receptor (PAC1(-/-)). These mice were viable and normoglycemic, but exhibited a slight feeding hyperinsulinemia. In vitro, in the isolated perfused pancreas, the insulin secretory response to PACAP was reduced by 50% in PAC1(-/-) mice, whereas the response to VIP was unaffected. In vivo, the insulinotropic action of PACAP was also acutely reduced, and the peptide induced impairment of glucose tolerance after an intravenous glucose injection. This demonstrates that PAC1 receptor is involved in the insulinotropic action of the peptide. Moreover, PAC1(-/-) mice exhibited reduced glucose-stimulated insulin secretion in vitro and in vivo, showing that the PAC1 receptor is required to maintain normal insulin secretory responsiveness to glucose. The defective insulinotropic action of glucose was associated with marked glucose intolerance after both intravenous and gastric glucose administration. Thus, these results are consistent with a physiological role for the PAC1 receptor in glucose homeostasis, notably during food intake.

Limiting the spread of penicillin-resistant Streptococcus pneumoniae: experiences from the South Swedish Pneumococcal Intervention Project

In an attempt to limit the spread of penicillin-resistant pneumococci (PRP), an intervention project was initiated in the Malmöhus County, southern Sweden in January 1995. The ongoing project combines traditional communicable disease control measures and actions aiming at reducing antibiotics consumption. All patients in the county with a nasopharyngeal culture positive for PRP with MIC of Penicillin G > or =0.5 mg/L are followed with nasopharyngeal cultures until PRP-negative. Nasopharyngeal cultures are obtained from family members and close contacts of the index cases. Preschool children carrying PRP are denied attendance at group day-care. From January 1995 to March 1997, 1,038 PRP-carriers (429 index cases and 609 contact cases) were identified. Children aged 1-6 years dominated (83%). Antibiotics sales decreased during the study period, and epidemiologic data indicate that the intervention may have limited the dissemination of PRP in the county, but further evaluation is needed.

Introduction and clonal spread of penicillin- and trimethoprim/sulfamethoxazole-resistant Streptococcus pneumoniae, serotype 9V, in southern Sweden

As part of an intervention project, all patients in Malmöhus county with a culture positive for penicillin-resistant pneumococci, MIC > or =0.5 mg/L (PRP), have been registered since January 1995. Nasopharyngeal specimens were obtained from family members and close contacts of identified carriers. Children were denied attendance at regular day-care until PRP-negative. In 1995 and 1996, PRP were isolated from 882 individuals, 364 of whom had clinical infection and the remaining of whom were asymptomatic carriers. In 49%, the PRP were of serogroup 9, with MIC of penicillin 0.5-2.0 mg/L and resistance to trimethoprim/sulfamethoxazole. Further analyses with serotyping and genetic fingerprinting suggested strongly that most of the isolates belonged to a single serotype 9V clone. Month by month, an apparently continuous spread appeared from one municipality to a neighboring one. In most communities, the serotype 9V PRP appeared and disappeared within a few months. The active procedures of the intervention project may have limited the spread of the clone in the county.

How to dress donor sites of split thickness skin grafts: a prospective, randomised study of four dressings

We investigated the effects of four dressings on donor sites of split thickness skin grafts. Eighty patients undergoing elective split thickness skin grafting were randomly allocated to one of four groups. The dressings were paraffin gauze, polyurethane foam, polyethane film, and polyurethane film. The main outcome measures were pain and discomfort, healing of donor sites, and time to remove dressings. Polyurethane film caused less pain and discomfort and was also easiest to remove. There were no differences in healing among the four groups.

The frequency of salpingitis and ectopic pregnancy as epidemiologic markers of Chlamydia trachomatis

BACKGROUND

To study the incidence of non-gonococcal salpingitis, gonococcal salpingitis and ectopic pregnancy in a defined population over a 28-year period on the assumption that the frequency of salpingitis and ectopic pregnancy may indirectly illustrate the epidemiological pattern of Chlamydia trachomatis.

DESIGN

A retrospective epidemiological study.

SETTING

University hospital with an urban catchment area.

PATIENTS

Five thousand two hundred and thirty-three patients admitted to the hospital between 1969 and 1996 with a diagnosis of ectopic pregnancy, non-gonococcal salpingitis, or gonococcal salpingitis.

RESULTS

The frequencies of both non-gonococcal and gonococcal salpingitis increased steeply early in the period under study, rising to a peak in the early 1970s, then decreasing throughout the period except for the last 3 years when a slight increase was seen again. The frequency of ectopic pregnancy showed a steady increase, peaking in the late 1980s and early 1990s and then declining at the end of the study period. While the introduction of more sensitive pregnancy tests and programs for assisted fertility would increase the rate of ectopic frequency the decline during the 'nineties cannot be accounted for in this way. The peak of salpingitis cases in the early 'seventies seems to be mirrored exactly by the peak of ectopic pregnancies fifteen years later in the late 'eighties.

CONCLUSION

The frequencies of salpingitis and of ectopic pregnancy can probably be used to estimate the incidence of preceding Chlamydia trachomatis. Thus the incidence of C. trachomatis has probably declined since the early 'seventies like that of N. gonorrheae.

Evaluation of a commercial test for antibodies to the chlamydial lipopolysaccharide (Medac) for serodiagnosis of acute infections by Chlamydia pneumoniae (TWAR) and Chlamydia psittaci

A commercial test (rELISA) based on a recombinant chlamydial lipopolysaccharide (LPS) antigen has been evaluated for the diagnosis of acute infections caused by Chlamydia pneumoniae (TWAR) and Chlamydia psittaci. This test and a microimmunofluorescence test (MIF) were compared in 160 patients with community-acquired pneumonia. Seventeen of nineteen cases with significant titre changes detected by rELISA were confirmed by MIF. The two remaining cases not confirmed by MIF were considered false-positive reactions. One case positive by MIF only was judged not to be a true-positive reaction. All three cases occurred in patients with Mycoplasma pneumoniae infection and may be the result of a mitogenic effect. High antibody titres have been used to indicate acute C. pneumoniae infection. We found high MIF or rELISA titres to be equally common in patients and controls; no association between the two tests was detected. An unexpected cross-reactivity between the rELISA antigen and parvovirus was observed, which might have diagnostic implications. Both MIF and rELISA detected acute C. pneumoniae and C. psittaci infection, and there was good agreement between the tests. Single serum diagnosis was generally not feasible with either MIF or rELISA.

Role of the enteric nervous system in the fluid and electrolyte secretion of rotavirus diarrhea

The mechanism underlying the intestinal fluid loss in rotavirus diarrhea, which often afflicts children in developing countries, is not known. One hypothesis is that the rotavirus evokes intestinal fluid and electrolyte secretion by activation of the nervous system in the intestinal wall, the enteric nervous system (ENS). Four different drugs that inhibit ENS functions were used to obtain experimental evidence for this hypothesis in mice in vitro and in vivo. The involvement of the ENS in rotavirus diarrhea indicates potential sites of action for drugs in the treatment of the disease.

Effects of group motor skill intervention on five- to six-year-old children with developmental coordination disorder

The purpose of this study was to determine whether group motor skill intervention is an effective form of treatment when added to consultative services in 5- to 6-year-old children with developmental coordination disorder (DCD). An experimental group of DCD children (n = 17) was compared with a DCD control group without intervention (n = 20). The intervention was conducted once a week for 10 weeks. No significant differences between the groups in either Movement ABC motor test or the Movement ABC checklist were found before or after this intervention. When subgroups with different categories of motor difficulties were compared, significantly more children with borderline motor difficulties in the experimental group than in the control group had changed (improved) their category after intervention. It is concluded that children with definite motor difficulties do not benefit from this type of intervention. Future research should include comparison of well-defined subgroups of children with DCD.

Seropositivity to chlamydial lipopolysaccharide and Chlamydia pneumoniae, systemic inflammation and stable coronary artery disease: negative results of a case-control study

OBJECTIVES

We investigated the association between seropositivity to chlamydial lipopolysaccharide (cLPS) or Chlamydia pneumoniae (CP) and angiographically documented coronary artery disease (CAD), and we examined the relationship between serostatus and markers of systemic inflammation.

BACKGROUND

The potential contribution of CP to atherogenesis is still a matter of debate, and inflammation has been suggested to represent the link between infection and atherosclerotic disease.

METHODS

Subjects age 40 to 68 years were recruited for this case-control study between October 1996 and November 1997: 312 patients with at least one coronary stenosis >50% and 479 age- and sex-matched blood donors without manifest CAD or history of angina. Antibodies against cLPS and CP, C-reactive protein (CRP), fibrinogen, plasma viscosity, leukocytes and neutrophils were determined. The study had a power of >80% to detect an odds ratio (OR) of 1.55 or above for the prevalence of immunoglobulin (IgG) antibodies against cLPS at a significance level of alpha = 0.05.

RESULTS

Prevalence of IgG antibodies against cLPS was not different between cases and controls (61% vs. 62%; p = 0.7). The adjusted OR for the presence of CAD given positive IgG serostatus against cLPS was 0.9 (95% CI; 0.6 to 1.3). Similarly, no difference in the prevalence of IgG antibodies against CP was seen (88% vs. 87%; p = 0.6); the adjusted OR was 1.0 (95% CI; 0.6 to 1.6). Markers of inflammation did not show any statistically significant difference between cLPS seropositives and seronegatives.

CONCLUSIONS

Our results indicate no strong association between CP and CAD, and increased systemic inflammation in patients with CAD does not seem to be due to seropositivity to cLPS or CP.

Nitric oxide modulates captopril-mediated angiotensin-converting enzyme inhibition in porcine iliac arteries

The influence of the angiotensin-converting enzyme inhibitor captopril on bradykinin-and angiotensin I-induced responses with special regard to nitric oxide (NO) was studied. Auxometric tension and angiotensin-converting enzyme activity was studied in isolated porcine iliac arteries. Captopril potentiated bradykinin-induced contraction of preparations with intact endothelium; this potentiation was not seen with the kininase I inhibitor mergepta or a bradykinin B(1)-receptor antagonist. Captopril did not affect bradykinin-induced relaxation. The captopril-mediated increase of bradykinin-induced contraction was only seen in preparations with intact endothelium, while captopril did not affect arterial strips treated with Nomega-nitro-L-arginine. Angiotensin I-induced contractions was less reduced by captopril when the strips were pretreated with Nomega-nitro-L-arginine. Both captopril and the NO donor S-nitroso-N-acetyl-penicillamine inhibited angiotensin-converting enzyme activity. An additional reduction in angiotensin-converting enzyme activity was seen when S-nitroso-N-acetyl-penicillamine was added to captopril-treated preparations. In conclusion, captopril increased bradykinin-induced contraction in a NO-dependent manner. This potentiation is probably mediated by the increased metabolism of bradykinin by kininase I, and the additive angiotensin-converting enzyme inhibitory effect of captopril and NO.

Crystal structure analysis of a pentameric fungal and an icosahedral plant lumazine synthase reveals the structural basis for differences in assembly

Lumazine synthase catalyzes the penultimate step in the synthesis of riboflavin in plants, fungi, and microorganisms. The enzyme displays two quaternary structures, the pentameric forms in yeast and fungi and the 60-meric icosahedral capsids in plants and bacteria. To elucidate the structural features that might be responsible for differences in assembly, we have determined the crystal structures of lumazine synthase, complexed with the inhibitor 5-nitroso-6-ribitylamino-2,4-pyrimidinedione, from spinach and the fungus Magnaporthe grisea to 3.3 and 3.1 A resolution, respectively. The overall structure of the subunit and the mode of inhibitor binding are very similar in these enzyme species. The core of the subunit consists of a four-stranded parallel beta-sheet sandwiched between two helices on one side and three helices on the other. The packing of the five subunits in the pentameric M. grisea lumazine synthase is very similar to the packing in the pentameric substructures in the icosahedral capsid of the plant enzyme. Two structural features can be correlated to the differences in assembly. In the plant enzyme, the N-terminal beta-strand interacts with the beta-sheet of the adjacent subunit, thus extending the sheet from four to five strands. In fungal lumazine synthase, an insertion of two residues after strand beta1 results in a completely different orientation of this part of the polypeptide chain and this conformational difference prevents proper packing of the subunits at the trimer interface in the icosahedron. In the spinach enzyme, the beta-hairpin connecting helices alpha4 and alpha5 participates in the packing at the trimer interface of the icosahedron. Another insertion of two residues at this position of the polypeptide chain in the fungal enzyme disrupts the hydrogen bonding in the hairpin, and the resulting change in conformation of this loop also interferes with proper intrasubunit contacts at the trimer interface.

Localization and activity of nitric oxide synthases in the gastrointestinal tract of Trypanosoma cruzi-infected mice

Chagas' disease, caused by the protozoan parasite, Trypanosoma cruzi, is associated with gastrointestinal abnormalities. Since nitric oxide (NO) has been shown to be a factor influencing intestinal function we evaluated the distributions and activities of the NO synthase (NOS) isoforms, in the gut of mice infected with T. cruzi. Ca2+-dependent (NOS1/NOS3) activity was decreased, whereas Ca2+-independent (NOS2) activity was increased in infected mice. NOS2-immunoreactivity was demonstrated in cells within the muscle layers and epithelium in infected mice and NOS1 immunoreactivity was seen in nerve structures. These data indicate that alterations in the NO-system may be important in the pathogenesis of the gastrointestinal manifestations in Chagas' disease.

Antibodies to Chlamydia trachomatis heat shock proteins in women with tubal factor infertility are associated with prior infection by C. trachomatis but not by C. pneumoniae

The antibody response to heat shock proteins 60 and 10 were studied in 163 patients with tubal factor infertility and in 163 age-matched pregnant women. The associations of these antibodies with specific antibodies to Chlamydia trachomatis and to Chlamydia pneumoniae as well as with antibodies to the common chlamydial lipopolysaccharide antigen were studied. Patients with tubal factor infertility had significantly higher frequencies and titres of all antibodies except to C. pneumoniae. In a logistic regression model an association was found between the prevalence of antibodies to the heat shock proteins and to C. trachomatis but no independent influence of antibodies to C. pneumoniae. No interaction between C. trachomatis and C. pneumoniae suggesting a synergistic effect was found although the heat shock proteins from these two organisms are immunologically similar. Antibodies to the chlamydial lipopolysaccharide also seemed to be related to C. trachomatis and not to C. pneumoniae in these women.

The functional intronless S-adenosylmethionine decarboxylase gene of the mouse (Amd-2) is linked to the ornithine decarboxylase gene (Odc) on chromosome 12 and is present in distantly related species of the genus Mus

S-Adenosylmethionine decarboxylase (AdoMetDC) is a key enzyme in the biosynthesis of polyamines. We have previously identified a mouse AdoMetDC gene that exhibits the hallmarks of a retroposon; that is, it has no introns, is flanked by direct repeats, and has a poly(dA) tract at its 3'-end. This gene, termed Amd-2, is not a processed pseudogene; rather, it is transcribed in a variety of mouse tissues and encodes a functional enzyme. In the current report, we present the sequence of a 6.7-kb genomic segment of the Amd-2 locus. Several sequences of interest, including an intercisternal A particle (IAP) element, a transposon-related sequence, and several expressed sequence tags (ESTs), were found within or near Amd-2. We also show, through analysis of an interspecific backcross, that Amd-2 is located on Chr 12, tightly linked to the gene (Odc) that encodes ornithine decarboxylase, another key enzyme in polyamine synthesis. Finally, we show that Amd-2 is present among several divergent species of the genus Mus. Thus, the integration event that generated Amd-2 may have occurred early during Mus evolution.

[Reduced frequency of resistant pneumococci in Southern Sweden. Community based disease control projects to minimize antibiotic resistance]

In an attempt to limit the spread of penicillin non-susceptible pneumococci (PNSP) in southern Sweden, early in 1995 an intervention project was launched, using a combination of traditional communicable disease control measures and actions aimed at reducing antibiotics consumption. Patients carrying PNSP (penicillin G MIC (0.5 mg/L) are monitored with nasopharyngeal cultures until PNSP-negative. Pre-school children are kept home from group day-care facilities. Previous antibiotic consumption was identified as a risk factor for PNSP carriage. Antibiotics sales decreased during the study period, and epidemiological findings suggest the dissemination of PNSP in the area to have been reduced by the intervention project.

Amplification and overexpression of p40 subunit of eukaryotic translation initiation factor 3 in breast and prostate cancer

Amplification at the long arm of chromosome 8 occurs in a large fraction of breast and prostate cancers. To clone the target genes for this amplification, we used suppression subtraction hybridization to identify overexpressed genes in the breast cancer cell line SK-Br-3, which harbors amplification at 8q (8q21 and 8q23-q24). A differentially expressed gene identified by SSH, the p40 subunit of eukaryotic translation initiation factor 3 (eIF3), was localized to 8q23 and found to be highly amplified and overexpressed in the breast and prostate cancer cell lines studied. High-level amplification of eIF3-p40 was found in 30% of hormone-refractory prostate tumors and in 18% of untreated primary breast tumors. In the vast majority of the cases, p40 and c-myc were amplified with equal copy numbers. Tumors with higher copy numbers of p40 than c-myc were also found. Expression of p40 mRNA was analyzed with in situ hybridization. The amplification of eIF3-p40 gene was associated with overexpression of its mRNA, as expected for a functional target gene of the amplification. These results imply that genomic aberrations of translation initiation factors, such as eIF3-p40, may contribute to the pathogenesis of breast and prostate cancer.

Chromosomal aberrations in breast cancer: a comparison between cytogenetics and comparative genomic hybridization

The analysis of chromosomal imbalances in solid tumors using comparative genetic hybridization (CGH) has gained much attention. A survey of the literature suggests that CGH is more sensitive in detecting copy number aberrations than is karyotyping, although careful comparisons between CGH and cytogenetics have not been performed. Here, we compared cytogenetics and CGH in 29 invasive breast cancers after converting the karyotypes into net copy number gains and losses. We found 15 tumors (56%) with a significant agreement between the two methods and 12 tumors (44%) where the methods were in disagreement (two cases failed CGH analysis). Interestingly, in 13 of the 15 tumors where the two methods were concordant, there was also a strong correlation between chromosome index and DNA index by flow cytometry. In the opposite situation, i.e., when chromosome and DNA indices were not matching, there was disagreement between cytogenetics and CGH in 10 of the 12 tumors. Of the discordant cases, all except one had a "simple" abnormal karyotype. Unresolved chromosomal aberrations (marker chromosomes, homogeneously staining regions, double minutes) could not completely explain the differences between CGH and karyotyping. A likely explanation for the discrepancies is that the methods analyzed different cell populations. Gains and losses found by CGH represented the predominant (often aneuploid) clone, whereas the abnormal, near-diploid karyotypes represented minor cell clone(s), which, for unknown reasons, had a growth advantage in vitro.

Morphological and biochemical investigation of nitric oxide synthase and related enzymes in the rat and pig urothelium

We investigated the enzymes involved in the NADPH-diaphorase (d) reaction in the rat and pig bladder urothelium. The urothelial cell layer displayed intense and uniform NADPH-d activity. Preincubation with the flavoprotein inhibitor diphenyleneiodionium chloride (DPI) and the alkaline phosphatase inhibitor levamisole concentration-dependently decreased the urothelial NADPH-d activity. Immunoreactivities to neuronal (n), endothelial (e), or inducible (i) nitric oxide synthase (NOS) were not detected in rat or pig urothelial cells. In rats, the urothelium was uniformly immunoreactive for NADPH cytochrome P450 reductase, whereas the pig urothelium displayed inconsistent labeling. In lipopolysaccharide (LPS)-treated rats, the bladder urothelium showed positive iNOS immunoreactivity. The iNOS labeling was found predominantly in cells located in the basal layer of the urothelium. In the pig bladder mucosa, a Ca2+-dependent NOS activity was evident in cytosolic and particulate fractions that was quantitatively comparable to the NOS activity found in the smooth muscle. In ultrastructural studies of urothelial cells, NADPH-d reaction products were found predominantly on membranes of the nuclear envelope, endoplasmatic reticulum and mitochondria. In conclusion, NADPH-d staining of the urothelium cannot be taken as an indicator for the presence of constitutively expressed NOS. Activity of alkaline phosphatase and cytochrome P450 reductase may account for part of the NADPH-d reaction in urothelial cells. However, LPS treatment of rats caused expression of iNOS in urothelial cells.

A non-nitrergic smooth muscle relaxant factor released from rat urinary bladder by muscarinic receptor stimulation

PURPOSE

To study the possible release of a relaxant factor from isolated rat bladder tissue.

MATERIALS AND METHODS

Thoracic aortae and urinary bladders were obtained from 55 female Sprague-Dawley rats. The bladder body was used in its original tubular shape as the donor tissue in a co-axial bioassay system, and the aorta served as acceptor tissue.

RESULTS

In a co-axial bioassay system with endothelium-free, norepinephrine-contracted, rat aortic preparations mounted within urothelium-intact urinary bladder, carbachol caused a concentration-dependent relaxation, amounting to 64+/-7% (n = 10) of the induced contraction, suggesting release of a relaxing factor. The relaxant effect of carbachol was lost if the urinary bladder segment was removed. However, the relaxation was affected neither by removal of the urothelium, nor by bladder segment inversion. It was resistant to inhibition of the L-arginine/nitric oxide and cyclo-oxygenase pathways, and unaffected by beta-adrenoceptor blockade and K+ channel inhibition. The relaxation was not associated with any significant changes in the intracellular levels of cGMP or cAMP.

CONCLUSION

A previously unrecognized non-adrenergic, non-nitrergic, non-prostanoid inhibitory mediator is released from the rat urinary bladder by muscarinic receptor stimulation. The physiological importance of such a factor remains to be established.

Short-term outcome of perinatal care in a Swedish county. Mortality, neonatal intensive care and overall evaluation of neuromotor function at 0-10 months of corrected age in preterm and term infants

Improvements in obstetrical and neonatal care during the last decades have led to a marked increase in survival rate of preterm and term infants. In order to study the short- and long-term outcome in infants who survived neonatal intensive care (NIC) and were born in the county of Uppsala between January 1st 1986 and April 30th 1989, a prospective long-term follow-up study was conducted. Epidemiological data on all infants born in the county during the study period and the short-term outcome, measured as overall neuromotor function at term and at 2, 4, 6 and 10 months of corrected age in 245 infants surviving NIC and 72 healthy control infants are presented. The infants' neuromotor function was evaluated with different clinical neurological methods. In the study population of NIC infants 85.9% survived the neonatal period. The early infant mortality was high in this group 11.6% compared to that of all infants born in the county of Uppsala (0.30%). Only a minority of the infants showed abnormal neuromotor function. A comparison of the results of the overall evaluation of neuromotor function at 10 months of age with those of the examinations made at an earlier age showed poor correspondence in individual infants, especially in preterm and very preterm infants.

The spontaneously hypertensive rat: insight into the pathogenesis of irritative symptoms in benign prostatic hyperplasia and young anxious males

Recent epidemiological studies have shown that hypertensive men are more likely to undergo surgical intervention for irritative voiding symptoms from BPH than age-matched controls. Indeed, noradrenergic nerves which regulate vascular tone also participate in the functional component of bladder outlet obstruction due to BPH. Newer, less invasive therapies for BPH such as thermal therapy can relieve symptoms yet do not eliminate obstruction based on urodynamic studies. Coincidentally, drugs such as alpha-adrenoceptor antagonists, which have been thought to relieve obstruction due to a peripheral effect, can be given intrathecally in animals to relieve urinary frequency due to obstruction. Taken together these observations implicate both peripheral and central sympathetic pathways in the motor control of the urinary bladder especially with disease states. We have used the hypertensive and behaviourally hyperactive spontaneously hypertensive rat (SHR), to investigate the roles sympathetic pathways or micturition. Elevated nerve growth factor (NGF) derived from vascular and bladder smooth muscle cells of the SHR appears to direct morphological, biochemical, and functional changes. The increase in NGF can apparently be explained by stabilization of its mRNA leading to increased synthesis in NGF. Bladders from SHRs develop a profuse noradrenergic hyperinnervation compared with the control WKY strain. Since afferents supplying the SHR bladder are hypertrophied, changes in afferent pathways are also likely. These differences in innervation and NGF in the SHR may explain changes in function. SHRs void 3 times as frequently as their genetic controls. Urinary frequency can be reduced by alpha-adrenoceptor antagonists. Cystometrograms performed in SHRs reveal lower bladder capacities and micturition volumes and the presence of unstable contractions compared with the WKY rat. Intrathecal, rather than intra-arterial administration of the alpha-adrenoceptor antagonist doxazosin reduces unstable contractions in the SHR. In vitro muscle bath studies have shown enhanced responses of SHR bladder smooth muscle to alpha-adrenoceptor agonists. It is likely that upregulation of NGF production causes sensory and possibly noradrenergic pathways to elicit hyperactive voiding. Increase in NGF in the adult bladder due to pathological conditions yields similar, yet distinct, consequences for voiding behaviour and innervation. Likewise, increased NGF in adult bladders following obstruction or inflammation triggers neuronal hypertrophy, enhanced reflex activity and urinary frequency. In contrast to the SHR, hyper-innervation is not observed. Moreover, peripheral or spinal alpha-adrenoceptor blockade eliminates urinary frequency following obstruction. These observations support the role for sympathetic pathways in the motor function of the bladder, especially in congenital or adult disease states. A similar process may underlie the neuroplasticity involved in alterations after obstruction or inflammation of the lower urinary tract in humans. The SHR strain raises the possibility that a common genetic defect exists capable of predisposing to both hypertension and overactivity of the urinary bladder. Whether a genetic predisposition to sustained bladder overactivity in response to inflammatory stimuli in obstruction exists in humans is an intriguing prospect.

Murine class I major histocompatibility complex H-2Dd: expression, refolding and crystallization

A truncated soluble form of the murine class I major histocompatibility antigen complex H-2Dd was cloned using an Escherichia coli based system. It was expressed, refolded in vitro and crystallized in a complex with murine beta2 microglobulin and the peptide RGPGRAFVTI from the V3-loop of the gp160 HIV-1 protein. Crystals belonging to the space group P212121 with cell dimensions a = 51.3, b = 92.5, c = 108.8 A were obtained using two different crystallization conditions. The crystals contain one complex per asymmetric unit and diffract to at least 2.4 A resolution.