Consensus sequence-based scheme for epidemiological typing of clinical and environmental isolates of Legionella pneumophila

A previously described sequence-based epidemiological typing method for clinical and environmental isolates of Legionella pneumophila serogroup 1 was extended by the investigation of three additional gene targets and modification of one of the previous targets. Excellent typeability, reproducibility, and epidemiological concordance were determined for isolates belonging to both serogroup 1 and the other serogroups investigated. Gene fragments were amplified from genomic DNA, and PCR amplicons were sequenced by using forward and reverse primers. Consensus sequences are entered into an online database, which allows the assignment of individual allele numbers. The resulting sequence-based type or allelic profile comprises a string of the individual allele numbers separated by commas, e.g., 1,4,3,1,1,1, in a predetermined order, i.e., flaA, pilE, asd, mip, mompS, and proA. The index of discrimination (D) obtained with these six loci was calculated following analysis of a panel of 79 unrelated clinical isolates. A D value of > 0.94 was obtained, and this value appears to be sufficient for use in the epidemiological investigation of outbreaks caused by L. pneumophila. The D value rose to 0.98 when the results of the analysis were combined with those of monoclonal antibody subgrouping. Sequence-based typing of L. pneumophila is epidemiologically concordant and discriminatory, and the data are easily transportable. This consensus method will assist in the epidemiological investigation of L. pneumophila infections, especially travel-associated cases, by which it will allow a rapid comparison of isolates obtained in more than one country.     

Parkinson’s Disease and Current Treatments for Its Gastrointestinal Neurogastromotility Effects

Purpose of Review

Gastrointestinal disturbances are seen in nearly all patients with Parkinson’s disease and lead to impaired quality of life, affect drug pharmacodynamics, and potentially worsen patient’s existing motor fluctuations, leading to further disability. Recent evidence links abnormal accumulations of α-synuclein aggregates in the periphery (gut) as seen in the cortex which causes dysfunctions impacting every level of the gastrointestinal tract from the esophagus, to the stomach, small bowel, colon, and rectum and can even predate the onset of the central neurologic disorder itself. Many treatments exist for the clinical phenotypes that result from the autonomic dysfunction and neuropathy involved in this neurodegenerative disorder.

Recent findings/summary

The treatments for the gut dysfunction seen in Parkinson’s disease (PD) depend on the specific area of the gastrointestinal tract affected. For dysphagia, behavioral therapies with speech pathology, neuromuscular electrical stimulation, or botulinum toxin injection may be helpful. For gastroparesis, domperidone may serve as an antiemetic while also blunting the hypotensive potential of Levodopa while new treatments such as ghrelin agonists may prove beneficial to help appetite, satiety, gastric emptying in those with constipation, and even improve constipation. Antibiotics such as rifaximin with poor systemic absorption may be used to treat small bacterial overgrowth also found in those with PD while the benefits of probiotics is yet to be determined. Finally, constipation in PD can be a reflection of pelvic floor dyssynergia, slow transit constipation, or both, thus treatments targeting the specific anorectal dysfunction is necessary for better outcomes.

     

Longitudinal analysis of retinal changes after branch retinal artery occlusion using optical coherence tomography.

BACKGROUND: Branch retinal artery occlusion (BRAO) causes inner retinal ischemia leading to permanent inner retinal dysfunction and visual field loss in affected retinal sectors. Optical coherence tomography (OCT) offers a novel way to evaluate in vivo retinal morphologic changes in BRAO in both acute and longitudinal phases. This case report describes OCT findings in BRAO at acute presentation and at follow-up, including the longitudinal evaluation of retinal and peripapillary retinal nerve fiber layer (RNFL) thickness. CASE REPORT: A 58-year-old white man with an acute branch retinal artery occlusion was examined by OCT at initial presentation and at 2, 4, and 8 months. At initial presentation, OCT line scan showed thickening and hyper-reflectivity of the inner retina with shadowing of photoreceptor and retinal pigment epithelial layers. At 2 months, hyper-reflectivity and thickening were reduced. At 4 months, the inner retina showed no hyper-reflectivity and was attenuated. Peripapillary RNFL thickness was reduced in corresponding sectors. Findings at the 8-month follow-up were unchanged from the 4-month visit. CONCLUSIONS: OCT provides useful information regarding the evolution of inner retinal attenuation in BRAO. Differential diagnosis of sectoral peripapillary RNFL thinning should include previous BRAO.     

Stimulation by theophylline and sildenafil of rat submandibular secretion of protein, epidermal growth factor and flow rate.

In the present study, the effects of cAMP- and cGMP-phosphodiesterase (PDE) inhibitors, theophylline, and sildenafil on secretion of protein, amylase and epidermal growth factor (EGF) and the flow rate from rat submandibular saliva were examined in an acute experiment. Theophylline at doses of 25, 50, 85mgkg(-1) and sildenafil at doses of 1, 2, 5mgkg(-1) were administered intraperitoneally 2h before saliva collection. Pure submandibular saliva was collected intraorally by microployethylene tubes under anesthesia using dissecting microscope.Theophylline at doses of 25, 50, 85mgkg(-1) increased salivary flow rate to 197% (P<0.01), 186% (P<0.01), and 209% of control, respectively. Sildenafil at doses of 1, 2, 5mgkg(-1) also increased flow rate to 232% (P<0.01), 182% (P<0.01), and 197% of control, respectively. Theophylline at doses of 25, 50, 85mgkg(-1) increased total protein concentration to 98% (P<0.01), 84% (P<0.01), and 210% of control, respectively. Sildenafil at doses of 2 and 5mgkg(-1) increased total protein concentration to 75% (P<0.01), and 240% of control, respectively. Theophylline at dose of 85mgkg(-1) increased EGF concentration to 60% (P<0.01) of control. Sildenafil at doses of 2 and 5mgkg(-1) increased EGF concentration to 44% (P<0.05) and 90% (P<0.01) of control, respectively. No statistically significant change was observed in amylase activity by administration of theophylline or sildenafil. The present results indicate that increasing intracellular levels of cAMP and cGMP have stimulatory effects on salivary functions. Regarding beneficiary effects of increased salivary flow rate and secretion of EGF in maintaining oral health, theophylline and sildenafil may find good places in some oral diseases.     

Hepatitis B virus genotypes in southwest Iran： Molecular, serological and clinical outcomes

AIM： To investigate the associations of hepatitis B virus （HBV） genotype with HBeAg and anti-HBe status, alanine aminotransferase （ALT） levels and HBV-DNA detection in different groups of HBV-infected patients in southwest Iran. METHODS： A total of 89 HBsAg-positive serum samples were collected from the same number of patients. All sera were then investigated to determine HBV DNA and serological markers. For all the polymerase chain reaction （PCR）-positive samples, biochemical, histopathological assays and genotyping were also performed. RESULTS： Genotype D was the only type of HBV foundin different clinical forms of acute and chronic infections. There was a high prevalence of HBeAg-negative HBV- infected patients with chronic hepatitis （52.7%）. Out of 55 patients with chronic hepatitis, seven （12.7%） were diagnosed with cirrhosis. A significant association between the presence of anti-HBe antibody and an increase in ALT level, among either HBeAg-negative （P = 0.01） or HBeAg-positive （P = 0.026） patients, was demonstrated. No significant differences were observed between the clinical outcomes of HBeAg-positive and -negative individuals （P = 0.24）. CONCLUSION： Genotype D has been recognized as the only type of HBV found in different clinical forms of HBV infections, including cirrhosis, among the residents of southwest Iran. Anti-HBe possibly plays a role in disease progression in some patients with chronic hepatitis, at least for a period of disease.     

Identification of SPARC-like 1 protein as part of a biomarker panel for Alzheimer's disease in cerebrospinal fluid

We have used proteomic fingerprinting to investigate diagnosis of Alzheimer's disease (AD). Samples of lumbar cerebrospinal fluid (CSF) from clinically-diagnosed AD cases (n = 33), age-matched controls (n = 20), and mild cognitive impairment (MCI) patients (n = 10) were used to obtain proteomic profiles, followed by bioinformatic analysis that generated a set of potential biomarkers in CSF samples that could discriminate AD cases from controls. The identity of the biomarker ions was determined using mass spectroscopy. The panel of seven peptide biomarker ions was able to discriminate AD patients from controls with a median accuracy of 95% (sensitivity 85%, specificity 97%). When this model was applied to an independent blind dataset from MCI patients, the intensity of signals was intermediate between the control and AD patients implying that these markers could potentially predict patients with early neurodegenerative disease. The panel were identified, in order of predictive ability, as SPARC-like 1 protein, fibrinogen alpha chain precursor, amyloid-β, apolipoprotein E precursor, serum albumin precursor, keratin type I cytoskeletal 9, and tetranectin. The 7 ion ANN model was further validated using an independent cohort of samples, where the model was able to classify AD cases from controls with median accuracy of 84.5% (sensitivity 93.3%, specificity 75.7%). Validation by immunoassay was performed on the top three identified markers using the discovery samples and an independent sample cohort which was from postmortem confirmed AD patients (n = 17).     

Glucocorticoid receptor disruption delays structural maturation in the lungs of newborn mice

In order to better understand the regulation of lung maturation by glucocorticoid-glucocorticoid receptor signaling, we studied glucocorticoid receptor (GR) hypomorphic mice with a mixed C57Bl6/129 sv background, in which disruption of exon 2 of the GR gene produces an N-terminal truncated GR protein. Four groups of mice were compared: homozygous mice that die at birth (non-survivors), homozygous mice that survive the neonatal period (survivors), heterozygotes and wild-type mice. Newborn non-survivors had 50% thicker airspace walls and a 46% decrease in the formation of secondary crests (the beginning of alveolar secondary septation) compared to either survivor or wild-type littermates (n = 9 mice in each group). The lung tissue to airspace ratio in homozygous mice not expressing wild-type GR (non-survivor and survivor) was increased compared to heterozygotes and wild-type mice that do express wild-type GR (0.91 +/- 0.08 vs. 0.49 +/- 0.02, n = 4 in each of the four subgroups), suggesting that complete morphological maturation of the lung is dependent on effective glucocorticoid signaling through a fully functional GR. Moreover, the relatively mature lung morphology of survivor versus non-survivor newborns suggests that a partial reduction in mesenchymal thickness is compatible with capillary remodeling, alveolar septation, and viable respiratory function after birth. Our findings suggest that in mice homozygous for disrupted GR, the severity of newborn respiratory insufficiency correlates with the degree of lung structural immaturity.