The Role of Computed Tomography and Radiographs in the Management of Intertrochanteric Fractures

Introduction

The Intertrochanteric fracture is a common hip trauma encountered in elderly patients. There is a lack of general agreement regarding its surgical management and choice of implant. Purpose of this study to conclude the final decision matrix regarding surgical management of intertrochanteric fractures based on parameters assessed on plain radiographs and CT scan.

Materials and methods

We have retrospectively evaluated 55 patients with intertrochanteric fractures presented to our institute after informed consent with radiographs and CT scans between July 2017 to July 2018. Assessment of various parameters regarding fracture geometry and classification as well as measurement was done.

Results

Mean lateral wall thickness in present study was 20.76mm. Incidence of coronal fragments was 90.9% and absence of coronal fragment in 5 patients. We noted the cases with anterior comminution had also a posterior comminution rendered the fracture unstable in almost 20 % cases.

Conclusion

Better understanding of fracture geometry by combined used of radiograph and CT scan enhanced preoperative planning, choice of suitable implant, helps in reduction manoeuvre and improving quality of osteosynthesis.

Corrigendum: The Vacc-SeqQC project: Benchmarking RNA-Seq for clinical vaccine studies

[This corrects the article DOI: 10.3389/fimmu.2022.1093242.].

The Vacc-SeqQC project: Benchmarking RNA-Seq for clinical vaccine studies

Introduction

Over the last decade, the field of systems vaccinology has emerged, in which high throughput transcriptomics and other omics assays are used to probe changes of the innate and adaptive immune system in response to vaccination. The goal of this study was to benchmark key technical and analytical parameters of RNA sequencing (RNA-seq) in the context of a multi-site, double-blind randomized vaccine clinical trial.

Methods

We collected longitudinal peripheral blood mononuclear cell (PBMC) samples from 10 subjects before and after vaccination with a live attenuated Francisella tularensis vaccine and performed RNA-Seq at two different sites using aliquots from the same sample to generate two replicate datasets (5 time points for 50 samples each). We evaluated the impact of (i) filtering lowly-expressed genes, (ii) using external RNA controls, (iii) fold change and false discovery rate (FDR) filtering, (iv) read length, and (v) sequencing depth on differential expressed genes (DEGs) concordance between replicate datasets. Using synthetic mRNA spike-ins, we developed a method for empirically establishing minimal read-count thresholds for maintaining fold change accuracy on a per-experiment basis. We defined a reference PBMC transcriptome by pooling sequence data and established the impact of sequencing depth and gene filtering on transcriptome representation. Lastly, we modeled statistical power to detect DEGs for a range of sample sizes, effect sizes, and sequencing depths.

Results and Discussion

Our results showed that (i) filtering lowly-expressed genes is recommended to improve fold-change accuracy and inter-site agreement, if possible guided by mRNA spike-ins (ii) read length did not have a major impact on DEG detection, (iii) applying fold-change cutoffs for DEG detection reduced inter-set agreement and should be used with caution, if at all, (iv) reduction in sequencing depth had a minimal impact on statistical power but reduced the identifiable fraction of the PBMC transcriptome, (v) after sample size, effect size (i.e. the magnitude of fold change) was the most important driver of statistical power to detect DEG. The results from this study provide RNA sequencing benchmarks and guidelines for planning future similar vaccine studies.

Outcomes of Desidustat Treatment in People with Anemia and Chronic Kidney Disease: A Phase 2 Study

BACKGROUND

Desidustat (ZYAN1) is an oral hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) that stimulates erythropoiesis. Stabilizing HIF via PHI is developing as a new therapeutic approach to treat anemia secondary to chronic kidney disease (CKD). This trial evaluated the safety, tolerability, and efficacy of Desidustat in adult CKD patients with anemia, who were not on dialysis.

METHODS

This was a Phase 2, randomized, double-blind, 6-week, placebo-controlled, dose-ranging, safety and efficacy study. A total of 117 eligible patients were randomized to 4 arms: 100, 150, 200 mg, or placebo. The investigational product was administered every alternate day for 6 weeks in fasting conditions. The primary endpoint was change in hemoglobin (Hb) from baseline to week 6.

RESULTS

Baseline demographics were well balanced among all the treatment arms. In the modified intent-to-treat (mITT) population, a mean Hb increase of 1.57, 2.22, and 2.92 g/dL in Desidustat 100, 150, and 200 mg arms, respectively, was observed post 6 weeks treatment. The responder rate (≥1 g/dL increase) was 66% in 100 mg, 75% in 150 mg, and 83% in 200 mg treatment arms, in the mITT population. Eighteen patients had at least one treatment emergent adverse event (TEAE), and 5 patients reported at least one drug-related mild TEAE. No death or serious adverse event was reported during the trial.

CONCLUSION

There was dose-related increase in Hb across all doses compared to placebo in mITT and per-protocol populations. Desidustat also increased pharmacokinetic parameters Cmax and AUC in dose-related manner. There was no significant change in vital signs, electrocardiographic parameters, or safety laboratory values. Clinical Trial Registration Number CTRI/2017/05/008534 (registered on May 11, 2017).

Slow Delivery Immunization Enhances HIV Neutralizing Antibody and Germinal Center Responses via Modulation of Immunodominance

Conventional immunization strategies will likely be insufficient for the development of a broadly neutralizing antibody (bnAb) vaccine for HIV or other difficult pathogens because of the immunological hurdles posed, including B cell immunodominance and germinal center (GC) quantity and quality. We found that two independent methods of slow delivery immunization of rhesus monkeys (RMs) resulted in more robust T follicular helper (TFH) cell responses and GC B cells with improved Env-binding, tracked by longitudinal fine needle aspirates. Improved GCs correlated with the development of >20-fold higher titers of autologous nAbs. Using a new RM genomic immunoglobulin locus reference, we identified differential IgV gene use between immunization modalities. Ab mapping demonstrated targeting of immunodominant non-neutralizing epitopes by conventional bolus-immunized animals, whereas slow delivery-immunized animals targeted a more diverse set of epitopes. Thus, alternative immunization strategies can enhance nAb development by altering GCs and modulating the immunodominance of non-neutralizing epitopes.

Ivabradine in Congestive Heart Failure: Patient Selection and Perspectives

Heart failure (HF) is the fourth-most frequent cause of death and remains a challenge for public health. Therapy goals for HF with reduced ejection fraction (HFrEF) are the improvement in the quality of life, prolonged survival, a reduction of signs and symptoms, and the prevention of hospitalization. Angiotensin-converting enzyme inhibitors, beta‐blockers, and mineralocorticoid receptor antagonists are the treatments of choice for HFrEF. Although ivabradine is not available in all countries, it is likely a new promising approach to improve outcomes in patients with HFrEF, either alone or with beta-blockers. Here, we review the current knowledge about ivabradine in HFrEF and assess its effect on outcomes in HF.

Diagnosis and Management of a Cardiac Amyloidosis Case Mimicking Hypertrophic Cardiomyopathy

Cardiac amyloidosis is an acquired heart disease secondary to the deposition of β-pleated amyloid proteins in heart tissue. Amyloid light chain (AL) amyloidosis is usually secondary to multiple myeloma and can rapidly deteriorate cardiac function, with high mortality. Up to 50% of AL patients have cardiac involvement presenting as heart failure, conduction abnormalities, and cardiomyopathies. One of the rare presentations is the likely simulation of disease with hypertrophic cardiomyopathies like left ventricular outflow tract (LVOT) obstruction due to the systolic anterior motion of the mitral valve and irregular septal hypertrophy secondary to amyloid deposits. We present a case of cardiac amyloidosis secondary to multiple myeloma who presented with dynamic LVOT obstruction resembling hypertrophic obstructive cardiomyopathy and complicated by acute pulmonary edema. These complicated cases can be initially treated for pulmonary edema with an elevation of the head of the bed, furosemide, and nitroglycerin intravenously. For multiple myeloma, chemotherapy was continued. Beta-blockers, calcium channel blockers and angiotensin-converting enzyme inhibitors, and aldosterone receptor blocker were avoided due to poor tolerability. After symptomatic control, the patient can likely be scheduled for septal myotomy and the placement of a pacemaker or implantable cardiac defibrillator to prevent any arrhythmias causing sudden cardiac death in these subsets of patients.

Carglumic Acid Treatment of a Patient with Recurrent Valproic Acid-induced Hyperammonemia: A Rare Case Report

Valproic acid, first manufactured as an anticonvulsant, is commonly used to treat both neurological and psychiatric conditions. A rare and deadly side effect of this medication is hyperammonemia, presenting as lethargy, confusion, seizure, and, ultimately, coma. In rare circumstances, hyperammonemia can be recurrent and devastating, especially in patients with an underlying N-acetyl glutamate synthase (NAGS) deficiency, as the valproic acid can enhance this enzyme deficiency and inhibit the conversion of ammonia into urea in the liver. For these subtypes of patients, the United States Food and Drug Administration (US FDA) has recently approved carglumic acid, a medication that can act as a scavenger by effectively increasing the levels of NAGS, ultimately enhancing the conversion of ammonia to urea. In our case report, we have mentioned a patient with treatment-resistant bipolar disorder, who presented with elevated ammonia levels secondary to valproic acid treatment. Valproic acid was the only drug that was effective in his case, so we initiated therapy to reduce his elevated ammonia levels. After a thorough evaluation, we found the patient had a genetic NAGS deficiency. Carglumic acid was initiated and proved efficacious in our patient.

Progestin-based contraception regimens modulate expression of putative HIV risk factors in the vaginal epithelium of pig-tailed Macaques

PROBLEM

In women, the use of progestin-based contraception may increase the risk of vaginal HIV acquisition. We previously showed in macaques that there is a significantly higher simian-human immunodeficiency virus (SHIV) acquisition rate in the luteal phase of the menstrual cycle, which presents a naturally high-progesterone state, and this may be attributable to altered expression of innate immune factors. We hypothesized that progestin-based contraception, especially depot medroxyprogesterone acetate (DMPA), would, in a similar way, affect mucosal immune factors that influence HIV acquisition risk.

METHOD OF STUDY

We used a pig-tailed macaque model to evaluate the effects of two progestin-based contraceptives, DMPA, and levonorgestrel (LNG)/ethinyl estradiol (EE)-based combined oral contraceptives (COCs), on innate mucosal factors. We compared the vaginal epithelial thickness data from previous studies and used cytokine profiling and microarray analysis to evaluate contraception-induced molecular changes in the vagina.

RESULTS

The administration of DMPA caused a reduction in the thickness of the vaginal epithelium relative to that of the follicular or luteal phase. DMPA also induced a significant increase in vaginal levels of the anti-inflammatory cytokine IL-10. Both DMPA- and LNG-based contraception induced a signature of gene expression similar to that of the luteal phase, only more exacerbated, including widespread downregulation of antiviral genes.

CONCLUSION

The use of progestin-based contraception might engender a milieu that poses an increased risk of HIV acquisition as compared to both the luteal and follicular phases of the menstrual cycle.

Pulmonary Involvement in Crohn's Disease: A Rare Case Report

Crohn’s disease (CD) is a granulomatous inflammatory disease that can involve any part of the gastrointestinal tract, from mouth to anus. In most cases, it remits and relapses in the terminal ileum, requiring treatment via steroid boluses. In rare cases, however, CD can involve the pulmonary system presenting as dyspnea on exertion and dry cough. We present a case of a 38-year-old man who developed shortness of breath, cough, and wheezing for one month after a colectomy procedure due to recurrent toxic megacolon. He recovered and tolerated extubation successfully and was prescribed mesalamine as maintenance therapy for CD. His pulmonary symptoms after the colectomy, along with his imaging and pulmonary function tests, indicated pulmonary involvement in the lungs as a progression of the primary inflammatory bowel disease. After confirming this diagnosis, he was treated with oral high-dose steroids after successful diagnosis, and the patient’s symptoms improved dramatically. This case highlights often overlooked CD bronchopulmonary involvement in the postoperative period.

A Review of the Mechanism of Antagonism of N-methyl-D-aspartate Receptor by Ketamine in Treatment-resistant Depression

The biochemical processes involved in depression go beyond serotonin, norepinephrine, and dopamine. The N-methyl-D-aspartate (NMDA) receptor has a major role in the neurophysiology of depression. Ketamine, one of the prototypical NMDA antagonists, works rapidly in controlling depressive symptoms, including acutely suicidal behavior, by just a single injection. Ketamine may rapidly increase the glutamate levels and lead to structural neuronal changes. Increased neuronal dendritic growth may contribute to synaptogenesis and an increase in brain-derived neurotrophic factor (BDNF). Activation of the mechanistic target of rapamycin (mTOR), as well as increased levels of BDNF, may increase long-term potentiation and result in an improvement in the symptoms of depression. The mechanisms of ketamine's proposed effect as an off-label treatment for resistant depression are outlined in this paper.

Sooty mangabey genome sequence provides insight into AIDS resistance in a natural SIV host

In contrast to infections with human immunodeficiency virus (HIV) in humans and simian immunodeficiency virus (SIV) in macaques, SIV infection of a natural host, sooty mangabeys (Cercocebus atys), is non-pathogenic despite high viraemia¹. Here we sequenced and assembled the genome of a captive sooty mangabey. We conducted genome-wide comparative analyses of transcript assemblies from C. atys and AIDS-susceptible species, such as humans and macaques, to identify candidates for host genetic factors that influence susceptibility. We identified several immune-related genes in the genome of C. atys that show substantial sequence divergence from macaques or humans. One of these sequence divergences, a C-terminal frameshift in the toll-like receptor-4 (TLR4) gene of C. atys, is associated with a blunted in vitro response to TLR-4 ligands. In addition, we found a major structural change in exons 3–4 of the immune-regulatory protein intercellular adhesion molecule 2 (ICAM-2); expression of this variant leads to reduced cell surface expression of ICAM-2. These data provide a resource for comparative genomic studies of HIV and/or SIV pathogenesis and may help to elucidate the mechanisms by which SIV-infected sooty mangabeys avoid AIDS.

BALDR: a computational pipeline for paired heavy and light chain immunoglobulin reconstruction in single-cell RNA-seq data

B cells play a critical role in the immune response by producing antibodies, which display remarkable diversity. Here we describe a bioinformatic pipeline, BALDR (BCR Assignment of Lineage using De novo Reconstruction) that accurately reconstructs the paired heavy and light chain immunoglobulin gene sequences from Illumina single-cell RNA-seq data. BALDR was accurate for clonotype identification in human and rhesus macaque influenza vaccine and simian immunodeficiency virus vaccine induced vaccine-induced plasmablasts and naïve and antigen-specific memory B cells. BALDR enables matching of clonotype identity with single-cell transcriptional information in B cell lineages and will have broad application in the fields of vaccines, human immunodeficiency virus broadly neutralizing antibody development, and cancer.

BALDR is available at https://github.com/BosingerLab/BALDR.

A case-control study of epidemiological factors associated with leptospirosis in South Gujarat region

BACKGROUND

The current study was planned to identify the epidemiological factors associated with leptospirosis in South Gujarat region using neighborhood controls.

METHODS

A total of 100 cases of leptospirosis occurred in South Gujarat region during the year 2012 were selected using simple random sampling. Three neighbors of the selected cases formed the controls (n = 300). A pretested structured questionnaire was used for data collection and data were analyzed using Epi Info 2007.

RESULTS

There was significant association of illiteracy (odds ratio [OR] =1.82, 95% confidence interval [CI] =1.14-2.89), working in waterlogged fields during the reference season (OR = 4.6, 95% CI = 1.6-17.9), swimming/bathing in canals, open air defecation practices, storage of cow dung in or surrounding house, residence in the house made up of cow dung walls, households with access of food to rodents, injuries over hands/foot during the endemic season (OR = 3, 95% CI = 1.8-4.8), and history of skin disease during the endemic season (OR = 4.2, 95% CI = 2-8.5), with leptospirosis. Only 10% of individuals had gumboots for protection. A total of 83 (83%) cases and 240 (80%) controls had taken oral doxycycline chemoprophylaxis (P > 0.05). Cases had taken chemoprophylaxis for a median 4 weeks (range: 1-8) while controls had taken the same for median 8 weeks (range = 1-8) (P < 0.002).

CONCLUSIONS

Although the commonly established factors appear to be associated with leptospirosis, the role of host factors seems to play a more important role in determining susceptibility to leptospirosis in exposed individuals.

Systems biology of immunity to MF59-adjuvanted versus nonadjuvanted trivalent seasonal influenza vaccines in early childhood

The dynamics and molecular mechanisms underlying vaccine immunity in early childhood remain poorly understood. Here we applied systems approaches to investigate the innate and adaptive responses to trivalent inactivated influenza vaccine (TIV) and MF59-adjuvanted TIV (ATIV) in 90 14- to 24-mo-old healthy children. MF59 enhanced the magnitude and kinetics of serum antibody titers following vaccination, and induced a greater frequency of vaccine specific, multicytokine-producing CD4(+) T cells. Compared with transcriptional responses to TIV vaccination previously reported in adults, responses to TIV in infants were markedly attenuated, limited to genes regulating antiviral and antigen presentation pathways, and observed only in a subset of vaccinees. In contrast, transcriptional responses to ATIV boost were more homogenous and robust. Interestingly, a day 1 gene signature characteristic of the innate response (antiviral IFN genes, dendritic cell, and monocyte responses) correlated with hemagglutination at day 28. These findings demonstrate that MF59 enhances the magnitude, kinetics, and consistency of the innate and adaptive response to vaccination with the seasonal influenza vaccine during early childhood, and identify potential molecular correlates of antibody responses.

Memory deficits associated with khat (Catha edulis) use in rodents

Khat products and chewing practices are common in East Africa, Middle East for centuries with concomitant socio-economic and public health repercussions. We assessed memory deficits associated with khat use in rodents. Young male CBA mice, 5-7 weeks old (n = 20), weighing 25-35 g were used. Mice were treated with either 40, 120 or 360 mg/kg body weight (bw) methanolic khat extract, or 0.5 ml saline for 10 days. Spatial acquisition, reversal and reference memory were assessed using modified Morris Water maze (MMWM). Mice treated with 40 mg/kg khat extract had longer (t4 = 4.12 p = 0.015) and t4 = 2.28 p = 0.065) escape latency on first and second day during reversal relative to the baseline. Under 120 mg/kg khat dose, the escape latency was shorter (t4 = -2.49 p = 0.05) vs (t3 = -2.5 p = 0.05) on third and fourth day. Further, treatment with 360 mg/kg khat extract resulted in significantly longer time (49.13, 33.5, 40.2 and 35.75) vs. (23.5 s), compared to baseline. Mice treated with khat or control preferred the target quadrant post acquisition while differential pattern was seen during reversal phase. Mice treated with 40 or 120 mg/kg khat showed significant preference for target quadrant. Substantial time (19.9) was spent in the old target compared to the new (16.9 s) by animals treated with highest dose however, the difference was not significant. There is a biological plausibility that chronic khat use may induce memory deficits and impair cognitive flexibility. The differential patterns of memory deficits may reflect the differences in dose effect as well as time dependent impairment.

Acne vulgaris, probiotics and the gut-brain-skin axis: from anecdote to translational medicine

Acne vulgaris has long been postulated to feature a gastrointestinal mechanism, dating back 80 years to dermatologists John H. Stokes and Donald M. Pillsbury. They hypothesised that emotional states (e.g. depression and anxiety) could alter normal intestinal microbiota, increase intestinal permeability, and contribute to systemic inflammation. They were also among the first to propose the use of probiotic Lactobacillus acidophilus cultures. In recent years, aspects of this gut-brain-skin theory have been further validated via modern scientific investigations. It is evident that gut microbes and oral probiotics could be linked to the skin, and particularly acne severity, by their ability to influence systemic inflammation, oxidative stress, glycaemic control, tissue lipid content, and even mood. This intricate relationship between gut microbiota and the skin may also be influenced by diet, a current area of intense scrutiny by those who study acne. Here we provide a historical background to the gut-brain-skin theory in acne, followed by a summary of contemporary investigations and clinical implications.

Reverse halo sign on chest imaging in a renal transplant recipient

Without proper treatment, the mortality of pulmonary mucormycosis is nearly 100%. Although the diagnosis is often made histologically, it can be suspected when patients have a reverse halo sign on computed tomography (CT) of the chest, along with the right clinical findings. We describe the case of a woman 7 months post renal transplant who presented with fevers, malaise, and chest pain. Her chest CT revealed a round, focal area of ground-glass attenuation surrounded by a complete rim of consolidation in the left upper lobe, consistent with the reverse halo sign. Pulmonary mucormycosis was diagnosed by transbronchial lung biopsy. She was successfully treated with combined medical and surgical therapies. In the context of this case, we provide a brief review of the diagnosis of pulmonary mucormycosis, with a focus on radiographic and pathologic findings.

Identification of pigment epithelium-derived factor as an adipocyte-derived inflammatory factor

Obesity is a major risk factor for insulin resistance, type 2 diabetes mellitus and cardiovascular disease. The pathophysiology of obesity is associated with chronic low-grade inflammation. Adipose tissue in obesity is significantly infiltrated by macrophages that secrete cytokines. The mechanisms of interaction between macrophages and adipocytes, leading to macrophage activation and increased cytokine release, remain to be elucidated. We reasoned that an adipocyte-derived factor might stimulate activation of macrophages. We have identified pigment epithelium-derived factor (PEDF) as a mediator of inflammation that is secreted by adipocytes and mediates macrophage activation. Recombinant PEDF activates macrophages to release tumor necrosis factor (TNF) and interleukin-1 (IL-1). The PEDF receptor adipose triglyceride lipase (ATGL) is required for PEDF-mediated macrophage activation. Selective inhibition of ATGL on macrophages attenuates PEDF-induced TNF production, and PEDF enhances the phosphorylation of p38 and extracellular signal-regulated kinase 1/2 mitogen-activated protein kinases. PEDF administration to rats results in increased serum TNF levels, and insulin resistance. Together, these findings suggest that PEDF secreted by adipocytes contributes to the onset and maintenance of chronic inflammation in obesity, and may be a therapeutic target in ameliorating insulin resistance.

Naked mole-rats: behavioural phenotyping and comparison with C57BL/6 mice

Naked mole-rats (NMR) live underground in large eusocial colonies in East Africa. They are extremely long-lived, some individuals having a lifespan of over 30 years. This has attracted research into longevity and possibly neurodegenerative disorders. However, very little is known about their basic behaviour, particularly in tests commonly used to characterise the behaviour of the laboratory rat and mouse, for which there is an enormous database. Recently the authors carried out comprehensive behavioural phenotyping on NMRs, comparing them on most tasks directly with C57BL/6 mice, the strain for which there is the largest behavioural database. The NMR colony had been obtained from the wild originally, but housed in an animal facility for about two years. Large inter-species differences in behaviour were seen between the mice and the NMRs. The latter had generally poor sensorimotor function, including cutaneous sensation, strength and even grasp reflexes. They were often reluctant to enter or head-dip into small holes that mice readily entered. Their vision (generally considered to be very poor) was sufficient to distinguish the two zones of a light-dark box. Although, as expected, the NMRs were capable of burrowing and digging, when individually housed they did not shred cotton material to make nests. Shredding was seen in a colony cage containing a queen, but no nests were made there even when a nesting box was provided. In cognitive testing, although, unlike mice and rats, they did not spontaneously alternate in a T-maze, they learnt rewarded alternation and a cued position task well. This study demonstrates how behaviour uniquely reflects the natural environment in which these unusual animals have evolved and live, and provides baseline data for future work.

The human respiratory syncytial virus nonstructural protein 1 regulates type I and type II interferon pathways

Respiratory syncytial viruses encode a nonstructural protein (NS1) that interferes with type I and III interferon and other antiviral responses. Proteomic studies were conducted on human A549 type II alveolar epithelial cells and type I interferon-deficient Vero cells (African green monkey kidney cells) infected with wild-type and NS1-deficient clones of human respiratory syncytial virus to identify other potential pathway and molecular targets of NS1 interference. These analyses included two-dimensional differential gel electrophoresis and quantitative Western blotting. Surprisingly, NS1 was found to suppress the induction of manganese superoxide dismutase (SOD2) expression in A549 cells and to a much lesser degree Vero cells in response to infection. Because SOD2 is not directly inducible by type I interferons, it served as a marker to probe the impact of NS1 on signaling of other cytokines known to induce SOD2 expression and/or indirect effects of type I interferon signaling. Deductive analysis of results obtained from cell infection and cytokine stimulation studies indicated that interferon-γ signaling was a potential target of NS1, possibly as a result of modulation of STAT1 levels. However, this was not sufficient to explain the magnitude of the impact of NS1 on SOD2 induction in A549 cells. Vero cell infection experiments indicated that NS1 targeted a component of the type I interferon response that does not directly induce SOD2 expression but is required to induce another initiator of SOD2 expression. STAT2 was ruled out as a target of NS1 interference using quantitative Western blot analysis of infected A549 cells, but data were obtained to indicate that STAT1 was one of a number of potential targets of NS1. A label-free mass spectrometry-based quantitative approach is proposed as a means of more definitive identification of NS1 targets.

Synthesis and Antibacterial and Antifungal Studies of Novel Nitrogen Containing Heterocycles from 5-Ethylpyridin-2-ethanol

A novel series of chalcones, pyrimidines and imidazolinone is described; chalcones (4a-o) were prepared from the lead molecule 4-[2-(5-ethylpyridin-2-yl)ethoxy]benzaldehyde. Pyrimidine (5a-o) derivatives were prepared from the reaction of chalcones and guanidine nitrate in alkali media. Imidazolinones (6a-o) were synthesized from reaction of pyrimidine and oxazolone derivatives (prepared by Erlenmeyer azlactone synthesis). The structures of the synthesized compounds were assigned on the basis of elemental analysis, IR, (1)H and (13)C NMR spectral data. All the products were screened against different strains of bacteria and fungi. Most of these compounds showed better inhibitory activity in comparison to the standard drugs.

Whole blood cytokine attenuation by cholinergic agonists ex vivo and relationship to vagus nerve activity in rheumatoid arthritis

OBJECTIVE

The central nervous system regulates innate immunity in part via the cholinergic anti-inflammatory pathway, a neural circuit that transmits signals in the vagus nerve that suppress pro-inflammatory cytokine production by an alpha-7 nicotinic acetylcholine receptors (alpha7nAChR) dependent mechanism. Vagus nerve activity is significantly suppressed in patients with autoimmune diseases, including rheumatoid arthritis (RA). It has been suggested that stimulating the cholinergic anti-inflammatory pathway may be beneficial to patients, but it remains theoretically possible that chronic deficiencies in this pathway will render these approaches ineffective.

METHODS

Here we addressed the hypothesis that inflammatory cells from RA patients can respond to cholinergic agonists with reduced cytokine production in the setting of reduced vagus nerve activity.

RESULTS

Measurement of RR interval variability (heart rate variability, HRV), in RA patients (n = 13) and healthy controls (n = 10) revealed that vagus nerve activity was significantly depressed in patients. Whole blood cultures stimulated by exposure to endotoxin produced significantly less tumour necrosis factor in samples from RA patients as compared to healthy controls. Addition of cholinergic agonists (nicotine and GTS-21) to the stimulated whole blood cultures however significantly suppressed cytokine production to a similar extent in patients and healthy controls.

CONCLUSION

These findings suggest that it is possible to pharmacologically target the alpha7nAChR dependent control of cytokine release in RA patients with suppressed vagus nerve activity. As alpha7nAChR agonists ameliorate the clinical course of collagen induced arthritis in animals, it may be possible in the future to explore whether alpha7nAChR agonists can improve clinical activity in RA patients.

The selective alpha7 agonist GTS-21 attenuates cytokine production in human whole blood and human monocytes activated by ligands for TLR2, TLR3, TLR4, TLR9, and RAGE

The cholinergic antiinflammatory pathway modulates inflammatory cytokine production through a mechanism dependent on the vagus nerve and the alpha7 subunit of the nicotinic acetylcholine receptor. GTS-21 [3-(2,4-dimethoxybenzylidene) anabaseine], a selective alpha7 agonist, inhibits inflammatory cytokine production in murine and human macrophages and in several models of inflammatory disease in vivo, but to date its antiinflammatory efficacy in human monocytes has not been characterized. We report here our findings that GTS-21 attenuates tumor necrosis factor (TNF) and interleukin 1beta levels in human whole blood activated by exposure to endotoxin. GTS-21 inhibited TNF production in endotoxin-stimulated primary human monocytes in vitro at the transcriptional level. The suppressive effect of GTS-21 was more potent than nicotine in whole blood and monocytes. Furthermore, GTS-21 attenuated TNF production in monocytes stimulated with peptidoglycan, polyinosinic-polycytidylic acid, CpG, HMGB1 (high-mobility group box 1 protein), and advanced glycation end product-modified albumin. GTS-21 decreased TNF levels in endotoxin-stimulated whole blood obtained from patients with severe sepsis. These findings establish the immunoregulatory effect of GTS-21 on human monocytes, and indicate the potential benefits of further exploration of GTS-21's therapeutic uses in human inflammatory disease.

Khat (Catha edulis) lowers plasma luteinizing hormone (LH) and testosterone secretion, but increases cortisol levels in male rabbits

AIM

This study investigated the effects of fresh khat extract on specific circulating hormones in male rabbits.

MATERIALS AND METHODS

A total of 25 male New Zealand White rabbits were divided into five groups each comprising five animals. The first four groups were fed four doses (1.5 g/kg, 4.5 g/kg, 13.5 g/kg and 40.5 g/kg body weight) of khat extract twice a week for 5 weeks while the last group, serving as control, was fed only normal saline via intragastric tube. Blood samples were collected at 15 min interval for up to 3 h after khat extract administration and plasma assayed for luteinizing hormone (LH), testosterone and cortisol levels using radioimmunoassay technique.

RESULTS

Khat extract at all doses significantly lowered (P<0.05) LH pulse frequency, area under LH curve, mean plasma LH and mean plasma testosterone levels. Plasma cortisol levels were significantly elevated (P<0.05) in khat-treated rabbits in a dose-dependent manner.

CONCLUSION

This study demonstrates that khat may impair reproductive function in male rabbits by interfering with sex hormone profiles.

Effect of Catha edulis (khat) on behaviour and its potential to induce seizures in Sprague Dawley rats

BACKGROUND

Khat is a plant whose young shoots and leaves are habitually used in Eastern Africa and the Arabian Peninsula as a drug of recreation. Although it is used without any control in these regions, it contains two controlled substances, cathinone (schedule I) which is present in fresh khat and cathine (schedule VI) which is a degradation product of cathinone abundant in old khat.

OBJECTIVE

To determine the effect of khat on locomotor behaviour and seizures in rats.

DESIGN

Experimental study.

SETTING

University of Nairobi.

SUBJECTS

Adult male rats in groups of six were given fresh khat, old khat, methylphenidate and saline at varying doses and observed over three hours.

RESULTS

Fresh khat at low doses and old khat at high doses stimulated locomotor activity. High doses of fresh and old khat induced stereotype behaviour and seizures.

CONCLUSION

The results show that khat stimulates locomotor and stereotypic behavioural activity and can induce seizures; results similar to those observed with amphetamine analogs.

Cholinergic anti-inflammatory pathway activity and High Mobility Group Box-1 (HMGB1) serum levels in patients with rheumatoid arthritis

High Mobility Group Box-1 (HMGB1) is a cytokine implicated in the pathogenesis of rheumatoid arthritis (RA) and other inflammatory diseases. The cholinergic anti-inflammatory pathway, a vagus nerve-dependent mechanism, inhibits HMGB1 release in experimental disease models. Here, we examine the relationship between vagus nerve activity and HMGB1 in patients with RA. We compared RR interval variability, an index of cardiac vagal modulation, HMGB1 and hsCRP serum levels, and disease activity scores in thirteen RA patients and eleven age- and sex-matched controls. In RA patients, serum levels of HMGB1 and hsCRP were elevated as compared with controls (HMGB1=71 ng/mL [45-99] vs. 18 ng/mL [0-40], P<0.0001; hsCRP=14.5 mg/L [0.7-59] vs. 1 mg/L [0.4-2.9], P<0.001). RR interval variability in RA patients was significantly decreased as compared with controls (HF=38 msec2 [14-80] vs. 288 msec2 [38-364], P<0.0001; rMSSD=20.9+/-9.79 msec, 52.6+/-35.3 msec, P<0.01). HMGB1 levels and RR interval variability were significantly related (rho=-0.49, P<0.01). HMGB1 serum levels significantly correlated with disease activity scores (DAS-28) in patients with RA (P=0.004). The study design does not enable a determination of causality, but the results are consistent with the hypothesis that decreased cholinergic anti-inflammatory pathway activity is associated with increased HMGB1 levels in patients with RA.

Cholinergic anti-inflammatory pathway activity and High Mobility Group Box-1 (HMGB1) serum levels in patients with rheumatoid arthritis

High Mobility Group Box-1 (HMGB1) is a cytokine implicated in the pathogenesis of rheumatoid arthritis (RA) and other inflammatory diseases. The cholinergic anti-inflammatory pathway, a vagus nerve-dependent mechanism, inhibits HMGB1 release in experimental disease models. Here, we examine the relationship between vagus nerve activity and HMGB1 in patients with RA. We compared RR interval variability, an index of cardiac vagal modulation, HMGB1 and hsCRP serum levels, and disease activity scores in thirteen RA patients and eleven age- and sex-matched controls. In RA patients, serum levels of HMGB1 and hsCRP were elevated as compared with controls (HMGB1=71 ng/mL [45-99] vs. 18 ng/mL [0-40], P<0.0001; hsCRP=14.5 mg/L [0.7-59] vs. 1 mg/L [0.4-2.9], P<0.001). RR interval variability in RA patients was significantly decreased as compared with controls (HF=38 msec2 [14-80] vs. 288 msec2 [38-364], P<0.0001; rMSSD=20.9+/-9.79 msec, 52.6+/-35.3 msec, P<0.01). HMGB1 levels and RR interval variability were significantly related (rho=-0.49, P<0.01). HMGB1 serum levels significantly correlated with disease activity scores (DAS-28) in patients with RA (P=0.004). The study design does not enable a determination of causality, but the results are consistent with the hypothesis that decreased cholinergic anti-inflammatory pathway activity is associated with increased HMGB1 levels in patients with RA.

"Mitotic drive" of expanded CTG repeats in myotonic dystrophy type 1 (DM1)

In myotonic dystrophy type 1 (DM1), an expanded CTG repeat shows repeat size instability in somatic and germ line tissues with a strong bias toward further expansion. To investigate the mechanism of this expansion bias, 29 DM1 and six normal lymphoblastoid cell lines (LBCLs) were single-cell cloned from blood cells of 18 DM1 patients and six normal subjects. In all 29 cell lines, the expanded CTG repeat alleles gradually shifted toward further expansion by "step-wise" mutations. Of these 29 cell lines, eight yielded a rapidly proliferating mutant with a gain of large repeat size that became the major allele population, eventually replacing the progenitor allele population. By mixing cell lines with different repeat expansions, we found that cells with larger CTG repeat expansion had a growth advantage over those with smaller expansions in culture. This growth advantage was attributable to increased cell proliferation mediated by Erk1,2 activation, which is negatively regulated by p21(WAF1). This phenomenon, which we designated "mitotic drive" , is a novel mechanism which can explain the expansion bias of DM1 CTG repeat instability at the tissue level, on a basis independent of the DNA-based expansion models. The lifespans of the DM1 LBCLs were significantly shorter than normal cell lines. Thus, we propose a hypothesis that DM1 LBCLs drive themselves to extinction through a process related to increased proliferation.

Mechanism of action of cathinone: the active ingredient of khat (Catha edulis)

OBJECTIVE

To review the current understanding of the mechanism of action of cathinone, the active ingredient of khat.

DATA SOURCE

Published experimental studies on the nature and action and effect of cathinone on the central nervous system both in animals and humans.

DATA EXTRACTION

Data was taken from work published on the mechanism of action of cathinone and also from work where the action of cathinone and amphetamine was compared.

DATA SYNTHESIS

Data from various studies on cathinone was compared for common themes with regards to its action and similarity with the known mechanism of action of amphetamine.

CONCLUSION

The experimental work shows that cathinone is a liable substance, structually related to amphetamine, and similarly to amphetamine, increases the levels of dopamine in the brain by acting on the cathecholaminergic synaspes. Hence the psychostimulant effect of khat can be accounted for by the mechanism of cathinone, which is considered to be its main active ingredient.

Multicentre evaluation of a commercial test for the rapid diagnosis of Clostridium difficile-mediated antibiotic-associated diarrhoea

An immunoassay for the detection of Clostridium difficile toxin A in stool samples (Clearview C. DIFF A; Unipath, UK) was evaluated against the cell cytotoxicity assay using 407 stool samples from patients suspected to have, or considered at risk of, antibiotic-associated diarrhoea. Of the samples tested, 98 were positive and 280 were negative by both tests (sensitivity 83.1%, specificity 96.9%). Following resolution of the 29 discrepant results, the sensitivity and specificity of the immunoassay were 91% and 98%, respectively, and the sensitivity for the cell cytotoxicity assay was calculated as 91.5%, with a specificity of 99%. The Clearview C. DIFF A test proved to be a rapid simple assay for the detection of Clostridium difficile toxin A in stool samples. The test was equally suited to single or batch testing, required minimal sample handling, and provided results within 30 min of applying the sample to the test unit.

UK study of intrapartum care for low risk primigravidas: a survey of interventions

STUDY OBJECTIVE

To determine the extent of intrapartum intervention received by primigravidas.

DESIGN

Cross sectional survey of NHS hospitals in the UK.

SETTING

One hundred and one randomly selected hospital maternity units.

PARTICIPANTS

Forty consecutive primigravid women, judged to be at low risk at the start of labour, in each hospital.

MAIN OUTCOME MEASURES

Seven groups of interventions or monitoring procedures were identified from the first, second, and third stages of labour: fetal monitoring, vaginal examinations, artificial rupture of membranes, augmentation of labour, pain relief, type of delivery, and episiotomy. Data were collected during 1993.

MAIN RESULTS

Ninety eight hospitals took part in the study and data were collected on 3160 low risk primigravidas. Seventy four per cent of these women had continuous cardiotocography. The proportion of women having restrictive or invasive fetal monitoring showed appreciable geographical variation for both the first and second stages of labour. Using the criterion of a vaginal examination every four hours and allowing for the length of each woman's labour, 72% had more vaginal examinations than expected; there was a significant geographical variation in the number of women receiving more than five examinations. Fifty three per cent had artificial rupture of membranes; the procedure was performed over a wide range of cervical dilatations (0 cm-10 cm). Thirty eight per cent of labours were augmented, most commonly by intravenous syntocinon; the procedure showed significant geographical variation. Twenty eight per cent had a spinal block or epidural analgesia for the relief of pain; this intervention varied by geographical region only for the second stage of labour. Over one quarter of the women required instrumental delivery. Forty six per cent had an episiotomy; the frequency of this intervention varied substantially by region. There were no infant deaths. Twelve babies were recorded at birth as having a congenital anomaly.

CONCLUSIONS

The rates of several interventions seem high for this low risk group and there was substantial geographical variation in the use of six interventions. Clinical trials are needed to evaluate the optimum criteria for using these interventions from which guidelines should be drawn up by local groups and the Royal College.

Evaluation of risk factors for Alzheimer's disease in elderly east Africans

A number of biological risk factors have been implicated for Alzheimer's disease (AD). The investigation of prevalence rates of AD in crosscultural populations has much potential in validating these factors. We previously assessed brain amyloid beta (A beta) protein deposition and other lesions associated with AD as possible markers for preclinical AD in elderly nondemented East Africans. In further analysis, we demonstrate that 17-19% of elderly East African subjects without clinical neurological disease exhibited neocortical A beta deposits and minimal neurofibrillary changes at necropsy that was qualitatively and quantitatively similar to that in an age-matched elderly control sample from Cleveland, OH. A beta deposits varied from numerous diffuse to highly localized neuritic plaques and were predominantly reactive for the longer A beta 42 species. In parallel studies, we evaluated another recently implicated factor in AD, the apolipoprotein E genotype. We found relatively high frequencies of the apolipoprotein E-epsilon 4 allele in elderly nondemented East Africans. The frequencies were comparable to those in other African populations but higher than in subjects from developed countries. Our limited study suggests that elderly East Africans acquire cerebral lesions found in AD subjects but the apolipoprotein E-epsilon 4 allele may not be a highly specific factor for the disease among East Africans.

Plasma luteinizing hormone levels in response to gonadotropin-releasing hormone agonist and clonidine in Trypanosoma congolense-infected female goats

Trypanosomiasis, a parasitic disease of humans and animals, occurs over a wide area of Africa and imposes a large socioeconomic burden on the people. In the present study, we investigated whether trypanosomiasis-induced reproductive disorders were due to pituitary or hypothalamic dysfunction by determining plasma luteinizing hormone (LH) response to gonadotropin-releasing hormone (GnRH) agonist or clonidine in Trypanosoma congolense-infected female goats. With GnRH agonist administration, the total amount of LH secreted over a 140-min sampling period on day 23 and day 60 postinfection was consistently higher (71 and 21%, respectively) in infected goats compared to controls. In contrast, clonidine administration to infected goats on day 28 and day 69 postinfection failed to significantly alter the LH pulse frequency or the mean LH pulse amplitude over a 80-min sampling period. The results, especially the lack of response to clonidine, indicate that trypanosomiasis impairs GnRH release from the hypothalamus.

Apolipoprotein E polymorphism in elderly east Africans

Current advances have shown the apolipoprotein E (APOE)-epsilon 4 allele to be highly associated with late-onset familial and sporadic Alzheimer's disease (AD) in Western populations. The association of APOE allele frequencies and dementia remain unknown in populations from developing countries. We recently initiated a project to examine APOE frequencies in non-demented and demented elderly East Africans. Blood DNA collected from two hospital-based populations showed that the APOE allele frequencies in a group of non-demented 67 Tanzanians over the age of 65 years were found to be 14% for epsilon 2, 61% for epsilon 3 and 25% for epsilon 4. By comparison, the frequency of APOE-epsilon 4 in an age-matched demented group was also 25%. Assessment of APOE genotypes in the group of elderly Kenyan subjects from Nairobi also revealed high frequencies of the epsilon 4 allele with no clear difference in frequency between demented and non-demented subjects. Our preliminary observations suggest that elderly East Africans with no apparent clinical AD possess relatively high APOE-epsilon 4 allele frequencies compared to normal ageing subjects from Western countries including African-Americans. These results appear similar to those reported in a recent study in Nigerian Africans where a lack of correlation between APOE-epsilon 4 allele frequency and Alzheimer type of dementia was noted, and imply that APOE-epsilon 4 allele may not necessarily be a risk factor in some populations of Africa.

Standards for ultrasound fetal growth velocity

OBJECTIVES

An ultrasound study to establish the nature and limits of fetal growth in a low risk population from 22 weeks of gestation until term.

DESIGN

Prospective, longitudinal ultrasound study of 274 low risk pregnancies involving organised scanning schedules with all measurements performed by one observer using the same equipment.

RESULTS

Growth velocity charts have been created for a number of ultrasound parameters including estimated fetal weight, by applying appropriate statistical methods to the serial data. The rates of growth of the biparietal diameter, femur length, abdominal area and estimated weight each have characteristic patterns demonstrating maximal growth rates at different gestations.

CONCLUSIONS

Appropriately derived and calculated ultrasound fetal growth velocity standards have been established. These data are suitable for the evaluation of ultrasonically estimated fetal growth rates in the prediction of adverse perinatal outcome and the further investigation of the role of the intrauterine environment in the origin of adult disease.

Neonatal cerebral arterial flow velocity waveforms in term infants with and without metabolic acidosis at delivery

To define the effects of acid base status at delivery on neonatal cerebral artery flow velocity waveform patterns obtained using Doppler ultrasound during the first week of life, a longitudinal comparative study of neonates born at term with and without evidence of metabolic acidosis in the umbilical artery was undertaken. Eighty-two appropriate for gestational age infants delivered after uncomplicated pregnancies with non-acidotic umbilical artery blood gases and in whom no neonatal complications were noted were studied to establish reference values of neonatal cerebral arterial vascular resistance index (RI) in normal term infants during the first week of life. A further 189 infants were grouped according to the presence and severity of metabolic acidosis at delivery, and also the presence of high risk features in the antenatal period. In the normal non-acidotic infants, over the first 24 h of life, there was a significant fall in the cerebral arterial resistance index (RI) in all the vessels examined, after which a steady state value was attained with no significant changes in vascular resistance index being noted during the remainder of the study period. The fall in RI between 12 and 24 h of age was consistent in all study groups. Infants with metabolic acidosis at delivery had blood flow patterns compatible with decreased resistance to flow in both anterior and middle cerebral arteries which persisted throughout the first week of life. This reduction in cerebral vascular resistance was most marked in those infants with severe metabolic acidosis. The majority of severely acidotic infants had a benign clinical outcome in the first week of life and all infants had normal cerebral ultrasound scans during the neonatal period. These findings suggest that metabolic acidosis at birth is associated with changes in neonatal cerebral arterial vascular resistance during the first week of life, and in the presence of benign clinical course the significance of this observation with regard to neurodevelopmental outcome requires evaluation.

Are 'notched' uterine arterial waveforms of prognostic value for hypertensive and growth disorders of pregnancy?

In a case-control controlled study of 86 women identified as having bilaterally 'notched' uterine arterial waveform patterns at 18 weeks, the presence of bilateral 'notched' uterine arterial waveforms at that time was associated with the subsequent development of hypertension and small-for-gestational-age infants, but the predictive value was poor. For those women in whom the bilateral uterine 'notches' were observed to persist to 24 weeks, the relative risk of developing proteinuric hypertension increased 14 times, and in these women the positive predictive value for the subsequent development of hypertension increased to 58.6% when compared with their matched controls. The identification of women with persistent bilateral uterine 'notches' provides a means of identifying women at significant risk of hypertensive and growth disorders at a stage when therapeutic intervention aimed at limiting the severity of the disease and its associated complications could be commenced.

Neonatal cerebral Doppler flow velocity waveforms in the pre-term infant with cerebral pathology

In a longitudinal study of 217 infants delivering at < 37 completed weeks gestation, Doppler flow velocity waveforms were obtained, and resistance index (RI) values calculated from the middle (MCA) and anterior (ACA) cerebral arteries during the first 10 days of life. Sixty infants demonstrated ultrasound evidence of cerebral pathology, of which five cases were congenital, and an additional 13 cases were complicated by patent ductus arteriosus during the study period. The Doppler data obtained during the first week of life from the remaining 42 infants who developed cerebral pathology, and 15 infants who had evidence of metabolic acidosis at delivery without ultrasound evidence of cerebral pathology were compared with local reference data obtained from non-acidotic infants with normal cranial ultrasound from 24 h of age. In those infants who had evidence of minor periventricular haemorrhage alone (Grade I/II PVH), there was no significant difference between the ACA or MCA RI during the study period compared with the reference data. In those groups of infants who demonstrated major PVH (Grade III/IV) or persistent periventricular flares, the ACA and MCA RI was found to be consistently significantly higher than the reference group throughout the study period. In those infants who developed ultrasound evidence of periventricular cystic leukomalacia (PVCL), the MCA RI was significantly lower than the reference data between 48 and 72 h of age, there being no significant difference in the ACA RI. The Doppler findings in those infants with evidence of metabolic acidosis at delivery (umbilical arterial pH < 7.20; BD > 8 mmol/l) but with normal ultrasound findings were similar to those infants who developed PVCL, namely a significant fall in MCA RI between 48 and 72 h of life, with no significant difference in the ACA RI during the study period. These findings suggest that variable changes in cerebral vascular resistance occur with the evolution of, or as a consequence of the development of cerebral pathology in the pre-term infant, and these changes of increased and decreased vascular resistance are discussed. Further investigation of the changes occurring in the cerebral circulation in the early neonatal period of infants who develop PVCL is required to clarify the vascular changes taking place, but if the findings of this study are confirmed, this technique may provide a means of identifying infants at risk of developing ischaemic cerebral pathology at an early stage when it may be possible to initiate therapeutic intervention to limit the cerebral damage.

Neonatal cerebral Doppler flow velocity waveforms in the uncomplicated pre-term infant: reference values

In a longitudinal study of 217 infants delivering at < 37 completed weeks gestation, Doppler flow velocity waveforms were obtained and resistance index (RI) values calculated from the middle (MCA) and anterior (ACA) cerebral arteries during the first 10 days of life. One hundred thirty-seven of these infants were non-acidotic at delivery and during the early neonatal period, and had normal cerebral ultrasound scans throughout the study period. These infants formed the reference group. In three gestational subgroups considered (< or = 32 weeks, 33-34 weeks, > or = 35 weeks) from the reference group, the median RI for both the ACA and MCA was noted to fall significantly during the first 12 h of life (P < 0.01 for all groups). For infants delivering at > or = 33 weeks gestation, both MCA and ACA RI values reached a steady state with no significant change in the median value for the remainder of the study period. For infants delivering at < or = 32 weeks, there was a further significant fall in both the MCA and ACA RI between 12 and 24 h of life (P < 0.05), after which a steady state value was reached. During the first 12 h of life the RI for both vessels was significantly higher in infants delivering at < or = 32 weeks compared to the more mature infants (P < 0.01), but for the remainder of the study period, there were no significant differences in RI values between the gestational subgroups.(ABSTRACT TRUNCATED AT 250 WORDS)

Risk of preterm delivery in pregnant women with group B streptococcal urinary infections or urinary antibodies to group B streptococcal and E. coli antigens

OBJECTIVE

To establish whether there is an association between preterm delivery and either group B streptococcal urinary infection or the presence of urinary antibodies to group B streptococcal or E. coli antigens.

DESIGN

A prospective study with urine culture and antibody measurement performed at the first antenatal visit and at 28 weeks gestation.

SETTING

Ninewells Hospital, Dundee.

SUBJECTS

Two thousand and forty-three women registering consecutively at an antenatal clinic.

MAIN OUTCOME MEASURE

Delivery at less than 37 weeks gestation.

RESULTS

No increase in preterm delivery was observed in women with positive urine cultures for group B streptococci either at booking or at 28 weeks, even when confirmed by positive repeat cultures. Preterm delivery was more common in women with elevated urinary antibodies to E. coli antigens at booking (relative risk 1.81, 95% CI 1.22-2.68, P = 0.005) and at 28 weeks (relative risk 2.36, 95% CI 1.60-3.48, P < 0.0001) and to group B streptococcal antigens at 28 weeks (relative risk 2.24, 95% CI 1.46-3.43, P = 0.0003).

CONCLUSIONS

These data do not support previous reports that positive urine cultures for group B streptococci are associated with an increased risk of preterm delivery. Our report of an association between elevated levels of urinary antibodies and preterm delivery is a new finding consistent with the possibility that a local inflammatory response to uro-genital infection may be important in stimulating the onset of preterm labour. The results suggest that screening for urinary antibodies at 28 weeks gestation might help to identify a group of women at increased risk of prematurity.

Nitric oxide: a new biological messenger molecule

Nitric oxide, a recently discovered gaseous biological messenger molecule, has been found to play a fundamental regulatory role in the body. It is involved in the cardiovascular, immune, reproductive, and digestive physiology and its presence in the brain indicates that it will have a neuronal function as well. Several areas of research suggest that low levels or absence of nitric oxide may be the underlying cause of some forms of essential hypertension and impotence, while over-production could be the cause of neuronal damage, septic shock, and immune-related tissue damage.