Salivary dysbiosis and the clinical spectrum in anti-Ro positive mothers of children with neonatal lupus.

Mothers giving birth to children with manifestations of neonatal lupus (NL) represent a unique population at risk for the development of clinically evident pathologic autoimmunity since many are asymptomatic and only become aware of anti-SSA/Ro positivity (anti-Ro+) based on heart block in their fetus. Accordingly, we hypothesized that the microbiome in saliva is associated with the development of autoreactivity and in some cases the progression in health status from benign to overt clinical disease including Sjögren's syndrome (SS) and systemic lupus erythematosus (SLE). The study comprised a clinical spectrum of anti-Ro+ mothers, all of whom gave birth to a child with NL: 9 were asymptomatic or had an undifferentiated autoimmune disease (Asym/UAS) and 16 fulfilled criteria for SS and/or SLE. Microbial diversity was reduced across all levels from kingdom to species for the anti-Ro+ mothers vs healthy controls; however, there were no significant differences between Asym/UAS and SS/SLE mothers. Relative abundance of Proteobacteria and more specifically class Betaproteobacteria decreased with clinical severity (healthy controls < Asym/UAS < SS/SLE). These ordered differences were maintained through the taxonomic hierarchy to three genera (Lautropia, Comamonas, and Neisseria) and species within these genera (L. mirabilis, N. flavescens and N. oralis). Biometric analysis comparing von Willebrand Factor domains present in human Ro60 with L. mirabilis proteins support the hypothesis of molecular mimicry. These data position the microbiome in the development of anti-Ro reactivity and subsequent clinical spectrum of disease.

Engineering the third wave of biocatalysis.

Over the past ten years, scientific and technological advances have established biocatalysis as a practical and environmentally friendly alternative to traditional metallo- and organocatalysis in chemical synthesis, both in the laboratory and on an industrial scale. Key advances in DNA sequencing and gene synthesis are at the base of tremendous progress in tailoring biocatalysts by protein engineering and design, and the ability to reorganize enzymes into new biosynthetic pathways. To highlight these achievements, here we discuss applications of protein-engineered biocatalysts ranging from commodity chemicals to advanced pharmaceutical intermediates that use enzyme catalysis as a key step.

A functional screen for recovery of 4'-phosphopantetheinyl transferase and associated natural product biosynthesis genes from metagenome libraries.

The single-module non-ribosomal peptide synthetase BpsA from Streptomyces lavendulae has the unique ability to autonomously synthesize a coloured product (indigoidine) from a single substrate (l-glutamine), conditional upon activation by a 4'-phosphopantetheinyl transferase (PPTase) partner. We show that bpsA can be expressed in an entD PPTase gene deleted mutant of Escherichia coli to yield a sensitive reporter strain for recovery of PPTase genes from metagenome libraries. We also show that recombinant bpsA constructs, generated by substitution of the native peptidyl carrier protein domain followed by directed evolution to restore function, can be used to increase the diversity of PPTase genes recovered from a sample. As PPTases are essential for activation of non-ribosomal peptide synthetase and polyketide synthase enzymes, they are frequently associated with secondary metabolite gene clusters. Nearly half of the PPTases recovered in our screening of two small-insert soil metagenome libraries were genetically linked to recognizable secondary metabolite biosynthetic genes, demonstrating that PPTase-targeting functional screens can be used for efficient recovery of natural product gene clusters from metagenome libraries. The plasticity and portability of bpsA reporter genes can potentially be exploited to maximize recovery and expression of PPTase-bearing clones in a wide range of hosts.

Opioid-related narcosis in a woman with myopathy receiving magnesium.

An Asian multiparous woman weighing 47 kg, who suffered from a rare myopathy, congenital fibre type disproportion, was given morphine 10 mg intramuscularly for labour analgesia. After delivery, she had diastolic hypertension and proteinuria and was prescribed magnesium sulphate. Some hours later she became unresponsive with little respiratory effort. Blood gas analysis revealed a respiratory acidosis. Naloxone administration reversed the symptoms. Further doses were required as the respiratory depression recurred. Opioid-related narcosis is the most likely diagnosis in this case. Other possible differential diagnoses were magnesium overdose or a post-ictal state. The presence of a myopathy could render this patient susceptible to the respiratory effects of opioids. Other explanations for an exaggerated and delayed response to opioids include co-administration of other respiratory depressant drugs such as magnesium sulphate, co-morbidity such as renal impairment and genetic variability in the metabolism of morphine. Robust guidelines and highlighting patients with risk factors are required to prevent this complication from recurring.

Chlorhexidine spray versus single use sachets for skin preparation before regional nerve blockade for elective caesarean section: an effectiveness, time and cost study.

INTRODUCTION: The importance of skin preparation before regional nerve blockade to prevent infection remains unchallenged. A multi-use spray chlorhexidine may have benefits over single use sachets in terms of convenience and cost, but its efficacy is unknown. We conducted a prospective randomised trial to compare spray and sachet chlorhexidine. METHODS: Elective caesarean section patients were randomised to receive chlorhexidine as a spray (chlorhexidine 0.5% in an alcoholic solution Hydrex DS Derma spray, Adams Healthcare, Leeds, UK) or sachet chlorhexidine (chlorhexidine 0.05% aqueous solution, Unisept, Seton. Leeds, UK) before a standardised combined spinal epidural technique. Skin colonisation was examined before skin preparation and again after epidural catheter removal. RESULTS: Both techniques were effective in reducing skin colonisation (P=0.0001). There was no difference in effectiveness between the groups, with the spray reducing skin colonisation from 88.5% before to 3% after catheter removal, compared with 90% to 12% in the sachet group. Time to achieve skin preparation was significantly reduced in the spray group (2.6 min compared to 4.5 min; P=0.02). The spray cost per patient was 0.01 compared to sachet 0.33. CONCLUSIONS: We suggest a chlorhexidine spray is as effective as single use sachets and is also quicker to apply and less costly.

Supraventricular tachycardia in pregnancy.

We present four cases of supraventricular tachycardia in pregnancy of varied aetiology. Risk factors for the development of supraventricular tachycardia and options for obstetric anaesthetic management, during pregnancy, labour, and at Caesarean section are discussed. We recommend the use of adenosine as first line therapy.

Liver in leprosy--I. Functional changes.

Liver function tests were carried out in 79 leprosy patients, out of which 28 patients were being treated and 42 patients were not receiving any treatment. The rest 9 patients were clinically quiescent. In the untreated group there were 28 tuberculoid and 14 lepromatus cases. The 28 patients receiving treatment were composed of equal number of lepromatus and tuberculoid groups. The liver function tests of 10 of the untreated tuberculoid patients were repeated after six months of specific therapy with D.D.S. The values of liver function tests of these patients were compared with that of 20 normal adults. The most important abnormality observed in the patients were a reversal of albumin/globulins ratio which was more common in the lepromatus group than in the tuberculoid group. Treatment with D.D.S. has resulted in the reduction of the serum globulin. There were no changes in transaminases and alkaline phosphatase activities in the untreated patients. But however a rise in the above enzymes were observed in patients on treatment. The mean serum cholesterol values of the patients were lower than that of the controls.

Coordination of respiration and swallowing: effect of bolus volume in normal adults.

The coordination of swallowing and respiration, as measured by nasal airflow, and the effect of changes in the volume of the swallow bolus (0-20 ml) were investigated in 12 normal subjects. Both nonbolus and bolus swallows were usually preceded and followed by expiratory airflow. Swallows followed by inspiratory airflow accounted for 20% of nonbolus swallows but decreased further in frequency in the presence of a bolus. Swallowing was associated with an apneic period lasting 1.90 +/- 0.26 s for nonbolus swallows. Based on the apneic period response to bolus volume, the subjects were divided into two groups. The apneic period decreased by 60% in seven of the subjects regardless of bolus volume. The remaining five subjects gradually increased swallow apnea as bolus volume was increased. At larger bolus volumes, the latter group also exhibited an earlier onset of the swallow apnea and an increase in the number of swallows preceded by inspiration. The duration of the swallow-associated respiratory cycle was similarly prolonged by an increase in bolus volume in both groups. The results indicate that the respiratory pattern associated with swallowing is modulated by the volume of the swallow bolus. Within the normal population, at least two different patterns of response to bolus volume are identified.

Liver in leprosy - II. Histopathological changes.

Liver biopsy studies were conducted in 77 leprosy patients. The first group of 42 patients were not on any treatment, whereas the 28 patients in the second group were being treated for varying periods. The rest 7 patients in the third group were clinically quiscent. Microscopic changes in the liver biopsy specimens were mainly epitheloid cell granuloma, foam cell granuloma, nonspecific inflammatory reaction characterised by lymphocytes and polymorpho nuclear leukocytes, and to a lesser degree hepatocytolysis and fatty degeneration. The lesions were fewer in the group getting treatment compared to the untreated group.

Isometric contraction of arm flexor muscles as a method of evaluating cardiac vagal tone in man.

1. We have previously shown that brief voluntary isometric contractions of upper arm flexor muscles performed for one respiratory cycle elicit a significant decrease in the R-R interval. The present study was designed to determine if similar changes are produced by non-voluntary electrically evoked contractions and, if so, to establish the consistency and repeatability of the associated changes in the R-R interval. 2. The heart rate (R-R interval) response to voluntary or non-voluntary brief isometric contraction equivalent to 40% of the maximum voluntary contraction was studied in 10 healthy young male subjects during controlled ventilation at supine rest. 3. The absolute values of R-R intervals occurring in any one of 10 arbitrary phases of a respiratory cycle were measured and plotted by a computer. 4. Both voluntary and non-voluntary contractions elicited similar changes in heart rate and R-R interval, which were greater during expiration than during inspiration. 5. This confirms our previous finding that the magnitude of the R-R interval changes, with brief isometric contraction, is positively related to the degree of cardiac vagal tone. 6. Analysis of the variability between repeated tests initiated in either inspiration or expiration revealed that there was significantly less variability with the electrically induced contraction. 7. It was concluded that electrically induced contractions of 40% maximal voluntary contraction are a viable alternative to voluntary contractions and provide a more controllable means of measuring cardiac vagal withdrawal.

Environmental Analysis by ab Initio Quantum Mechanical Computation and Gas Chromatography/Fourier Transform Infrared Spectrometry.

Computational chemistry, in conjunction with gas chromatography/mass spectrometry/Fourier transform infrared spectrometry (GC/MS/FT-IR), was used to tentatively identify seven tetrachlorobutadiene (TCBD) isomers detected in an environmental sample. Computation of the TCBD infrared spectra was performed with the Gaussian quantum chemistry software. The Hartree-Fock/6-31G* level of theory was employed, with IR frequencies scaled by a standard factor of 0.89. This approach shows great promise as a means of characterizing or confirming environmental analyte identifications when standard spectra, or pure standards required to measure standard spectra, are unavailable.