Intracellular Reservoir of Streptococcus pyogenes In Vivo: A Possible Explanation for Recurrent Pharyngotonsillitis

Numerous theories have been presented that attempt to explain the frequent recurrences of pharyngotonsillitis caused by Streptococcus pyogenes; these recurrences occur after seemingly adequate antibiotic treatment. We previously have demonstrated that S pyogenes can survive for up to 7 days intracellularly in immortalized human respiratory epithelial cells grown in an antibiotic supplemented medium. Viable S pyogenes were externalized and established an extracellular infection, whenever the extracellular antibiotic was removed. We have investigated the presence of intracellular S pyogenes in two in vivo studies using respiratory epithelial cells collected from patients with tonsillitis and the tonsils of asymptomatic carriers. Electron microscopy and immunohistochemistry demonstrated intracellular S pyogenes in pharyngeal epithelial cells in 13 of 14 patients with tonsillitis (93%). Furthermore, intracellular S pyogenes were found in macrophage-like cells in eight (73%) and in epithelial cells in four (36%) tonsils from 11 asymptomatic S pyogenes carriers. These in vivo data strongly support the hypothesis that intracellular S pyogenes can constitute a reservoir of bacteria with the potential to cause reinfections     

Chlamydial antibodies and risk of prostate cancer.

OBJECTIVE: We assessed the risk of prostate cancer by exposure to Chlamydia trachomatis. METHOD: Seven hundred thirty eight cases of prostate cancer and 2,271 matched controls were identified from three serum sample banks in Finland, Norway, and Sweden by linkage to the population based cancer registries. RESULTS: A statistically significant inverse association (odds ratio, 0.69; 95% confidence interval, 0.51-0.94) was found. It was consistent by different serotypes and there was a consistent dose-response relationship. CONCLUSION: C. trachomatis infection is not likely to increase the risk of prostate cancer. Whether the inverse relationship is true or due to difficulties in measuring the true exposure in prostatic tissue by serology, confounders or other sources of error remain open.     

Amyloid and metabolic positron emission tomography imaging of cognitively normal adults with Alzheimer's parents

This study examines the relationship between fibrillar beta-amyloid (Aβ) deposition and reduced glucose metabolism, a proxy for neuronal dysfunction, in cognitively normal (NL) individuals with a parent affected by late-onset Alzheimer's disease (AD). Forty-seven 40–80-year-old NL received positron emission tomography (PET) with ¹¹C-Pittsburgh compound B (PiB) and 18F-fluoro-2-deoxy-d-glucose (FDG). These included 19 NL with a maternal history (MH), 12 NL with a paternal history (PH), and 16 NL with negative family history of AD (NH). Automated regions of interest, statistical parametric mapping, voxel-wise intermodality correlations, and logistic regressions were used to examine cerebral-to-cerebellar PiB and FDG standardized uptake value ratios across groups. The MH group showed higher PiB retention and lower metabolism in AD regions compared with NH and PH, which were negatively correlated in posterior cingulate, frontal, and parieto-temporal regions (Pearson r ≤ −0.57, p ≤ 0.05). No correlations were observed in NH and PH. The combination of Aβ deposition and metabolism yielded accuracy ≥ 69% for MH vs. NH and ≥ 71% for MH vs. PH, with relative risk = 1.9–5.1 (p values < 0.005). NL individuals with AD-affected mothers show co-occurring Aβ increases and hypometabolism in AD-vulnerable regions, suggesting an increased risk for AD.     

A 13-year follow-up of Finnish patients with Salla disease

Background

Salla disease (SD) is a rare lysosomal storage disorder leading to severe intellectual disability. SD belongs to the Finnish disease heritage, and it is caused by mutations in the SLC17A5 gene. The aim of the study was to investigate the course of neurocognitive features of SD patients in a long-term follow-up.

Methods

Neuropsychological and neurological investigations were carried out on 24 SD patients, aged 16–65 years, 13 years after a similar examination.

Results

The survival analysis showed excess mortality among patients with SD after the age of 30 years. The course of the disease was progressive, but follow-up of SD patients revealed that motor skills improved till the age of 20 years, while mental abilities improved in most patients till 40 years of age. Verbal comprehension skills did not diminish during the follow-up, but productive speech deteriorated because of dyspraxia and dysarthria. Motor deficits were marked. Ataxia was prominent in childhood, but it was replaced by athetotic movements during the teens. Spasticity became more obvious with age especially in severely disabled SD patients.

Conclusions

Younger SD patients performed better in almost every task measuring mental abilities that then seem to remain fairly constant till early sixties. Thus, the results indicate better prognosis in cognitive skills than earlier assumed. There is an apparent decline in motor skills after the age of 20 years. The early neurocognitive development predicts the later course of motor and cognitive development.     

Lack of CD44 variant 6 expression in rectal cancer invasive front associates with early recurrence

AIM: To investigate the prognostic value of CD44 variant 6 (CD44v6), a membranous adhesion molecule, in rectal cancer.METHODS: Altogether, 210 rectal cancer samples from 214 patients treated with short-course radiotherapy (RT, n = 90), long-course (chemo) RT (n = 53) or surgery alone (n = 71) were studied with immunohistochemistry for CD44v6. The extent and intensity of membranous and cytoplasmic CD44v6 staining, and the intratumoral membranous staining pattern, were analyzed.RESULTS: Membranous CD44v6 expression was seen in 84% and cytoplasmic expression in 81% of the cases. In 59% of the tumors with membranous CD44v6 expression, the staining pattern in the invasive front was determined as “front-positive” and in 41% as “front-negative”. The latter pattern was associated with narrower circumferential margin (P = 0.01), infiltrative growth pattern (P < 0.001), and shorter disease-free survival in univariate survival analysis (P = 0.022) when compared to the “front-positive” tumors.CONCLUSION: The lack of membranous CD44v6 in the rectal cancer invasive front could be used as a method to identify patients at increased risk for recurrent disease.     

DNA Flow Cytometry in Surgically Treated Lung Cancer: Prognostic Significance

Although DNA aneuploidy and high proliferative activity (S-phase fraction, SPF) of tumour cells, measured by flow cytometry, have proved to be indicators of poor prognosis in most solid tumours, there have been conflicting results in lung cancer studies. During a four-year period we studied the prognostic significance of DNA ploidy and SPF in 99 surgically treated lung cancer patients. Flow cytometric analysis was done from archival, formalin-fixed, paraffin-embedded tumour specimens. DNA index and SPF were determined, using MultiCycle software with sliced nuclear correction to compensate for debris. There were 61 DNA diploid and 38 DNA aneuploid tumours. The median SPF was 10.2%. Neither ploidy nor SPF was associated with previously known prognostic factors. Survival was poorer in patients with aneuploid tumours than in the other patients, but the difference was not statistically significant. DNA ploidy and SPF thus do not seem to be useful prognostic indicators in surgically treated lung cancer.