Epidemiology of community-acquired pneumonia in adults: a population-based study.

In this prospective study, the authors assessed the incidence, aetiology, and outcome of patients with community-acquired pneumonia in the general population. From December 1993 to November 1995, a study was performed in a mixed residential-industrial urban population of the "Maresme" region in Barcelona, Spain. All subjects > or =14 yrs of age (annual average population size 74,368 inhabitants) with clinically suspected community-acquired pneumonia were registered. All cases were re-evaluated by chest radiographs on the 5th day of illness and at monthly intervals until complete recovery. Urine and blood samples were obtained for culture and antigen detection. When lower respiratory tract secretions were obtained, these were also cultured. There were 241 patients with community-acquired pneumonia, with an annual incidence rate of 1.62 cases (95% confidence interval, 1.42-1.82) per 1,000 inhabitants. Incidence rates increased by age groups and were higher in males than in females. Of 232 patients with aetiological data, 104 had an identifiable aetiology. A total of 114 pathogens were found (single pathogen 94, two pathogens 10). There were 81 episodes of bacterial infection and 33 of viral infection. The most common pathogens were Streptococcus pneumoniae, Chlamydia pneumoniae, and influenza A and B viruses. No case of Hantavirus infection was found. The rate of hospital admission was 61.4% with a mean+/-SD length of 11.7+/-10.1 days, a mean period of 23.0+/-14.3 days inactivity, and an overall mortality rate of 5%. The high rate of hospital admission, prolonged stay in hospital, and long period of inactivity all continue to constitute a social and health care burden of community-acquired pneumonia.     

Increased Amoeboid Microglial Density in the Olfactory Bulb of Parkinson's and Alzheimer's Patients

The olfactory bulb (OB) is affected early in both Parkinson's (PD) and Alzheimer's disease (AD), evidenced by the presence of disease‐specific protein aggregates and an early loss of olfaction. Whereas previous studies showed amoeboid microglia in the classically affected brain regions of PD and AD patients, little was known about such changes in the OB. Using a morphometric approach, a significant increase in amoeboid microglia density within the anterior olfactory nucleus (AON) of AD and PD patients was observed. These amoeboid microglia cells were in close apposition to β‐amyloid, hyperphosphorylated tau or α‐synuclein deposits, but no uptake of pathological proteins by microglia could be visualized. Subsequent analysis showed (i) no correlation between microglia and α‐synuclein (PD), (ii) a positive correlation with β‐amyloid (AD), and (iii) a negative correlation with hyperphosphorylated tau (AD). Furthermore, despite the observed pathological alterations in neurite morphology, neuronal loss was not apparent in the AON of both patient groups. Thus, we hypothesize that, in contrast to the classically affected brain regions of AD and PD patients, within the AON rather than neuronal loss, the increased density in amoeboid microglial cells, possibly in combination with neurite pathology, may contribute to functional deficits.     

Compression asymmetric static experimental model of degenerative disk diseases

We propose an experimental model of degenerative-dystrophic changes in intervertebral disks of rat tail. The results of X-ray examination and histological studies showed that degenerative changes in the disk tissues caused by experimental compression of intervertebral disks in rat tails are identical to those in humans. __________ Translated from Kletochnye Tehnologii v Biologii i Medicine, No. 3, pp. 139–142, July, 2007     

Prevalence of hidden carbon monoxide poisoning in auto service workers; a prospective cohort study

Background

Carbon monoxide (CO) is formed as a result of the incomplete burning of hydrocarbon-containing fuels such as natural gas, coal, liquid petroleum gas, and wood. CO is a colorless, odorless, and poisonous gas that produces various acute and chronic effects in CO-exposed people. In this study, we aimed to measure CO levels in auto care repairmen with chronic CO-related illnesses using a serial, non-invasive method.A prospective cohort study.

Methods

A total of 99 people from six different auto-repair services were included in the study. Carboxyhemoglobin (COHb) levels were measured at four different times with 2-hour intervals starting at 08:00 AM. Data concerning employees’ ages, working hours, smoking statuses, and types of home heating fuel were collected. A control group of 100 cases was created based on this data. The measurements were done on the control group in the morning with a Masimo Rad-57 CO-oximeter.

Results

The highest mean (± SD) COHb value was 7.04%?±?3.32% after the third measurement. The mean value for the control group was 1.61%?±?1.43%. A statistically significant difference between the groups was found for each value.

Discussion

We determined that the risk of being affected by CO is high in buildings in which the auto services were located. The effects of chronic or prolonged exposure to low amounts of CO were found to be ambiguous. However, in some studies, it was found that low-grade CO exposure could lead to coronary artery disease and some neurological complications. Therefore, it is necessary to be careful about the health of employees who have been exposed to CO.

Conclusions

We concluded that there is a need for more detailed studies concerning chronic CO poisoning. Also, in workplaces in which there is high exposure to CO, proper workplace safety measures should be taken to reduce this gas’s harmful effects to employees.

     

A microdevice for parallelized pulmonary permeability studies

We describe a compartmentalized microdevice specifically designed to perform permeability studies across a model of lung barrier. Epithelial cell barriers were reproduced by culturing Calu-3 cells at the air-liquid interface (AIC) in 1 mm² microwells made from a perforated glass slide with an embedded porous membrane. We created a single basolateral reservoir for all microwells which eliminated the need to renew the growth medium during the culture growth phase. To perform drug permeability studies on confluent cell layers, the cell culture slide was aligned and joined to a collection platform consisting in 35 μL collection reservoirs connected at the top and bottom with microchannels. The integrity and functionality of the cell barriers were demonstrated by measurement of trans-epithelial electrical resistance (TEER), confocal imaging and permeability assays of ¹⁴C-sucrose. Micro-cell barriers were able to form confluent layers in 1 week, demonstrating a similar bioelectrical evolution as the Transwell systems used as controls. Tight junctions were observed throughout the cell-cell interfaces, and the low permeability coefficients of ¹⁴C-sucrose confirmed their functional presence, creating a primary barrier to the diffusion of solutes. This microdevice could facilitate the monitoring of biomolecule transport and the screening of formulations promoting their passage across the pulmonary barrier, in order to select candidates for pulmonary administration to patients.     

Functional imaging of visual semantic processing in the human brain

Previous neuroimaging studies have identified a large network of cortical areas involved in semantic processing in the human brain, which includes left occipito-temporal and inferofrontal areas. Most studies, however, investigated exclusively the associative/functional semantic knowledge by using mainly words and/or language related tasks, and this factor may have contributed to the large left hemisphere superiority found in semantic processing and to the controversial involvement of left prefrontal structures. The present study investigates the neural basis of visual objects knowledge, accessed exclusively through pictorial information. Regional cerebral blood flow (rCBF) was assessed using positron emission tomography (PET) during 3 conditions in right-handed normal volunteers: resting with eyes closed, retrieval of semantic information related to visual properties of objects (real size), and visual categorization based on physical properties of the image. Confirming previous experiments and neuropsychological findings, most activations were found in left occipito-temporal areas during retrieval of visual semantic knowledge. The absence of any activation in the left prefrontal inferior cortex for visual semantic processing confirms recent observations which suggest that this region would not be involved in retrieval of visual semantic knowledge from living entities. Rather, such knowledge about visual properties of objects, situated closely to cortical regions mediating perception of the visual attributes, can be retrieved directly from these regions when visual images are used as entry level stimuli.     

Assessment of rigid multi-modality image registration consistency using the multiple sub-volume registration (MSR) method

Registration of different imaging modalities such as CT, MRI, functional MRI (fMRI), positron (PET) and single photon (SPECT) emission tomography is used in many clinical applications. Determining the quality of any automatic registration procedure has been a challenging part because no gold standard is available to evaluate the registration. In this note we present a method, called the 'multiple sub-volume registration' (MSR) method, for assessing the consistency of a rigid registration. This is done by registering sub-images of one data set on the other data set, performing a crude non-rigid registration. By analysing the deviations (local deformations) of the sub-volume registrations from the full registration we get a measure of the consistency of the rigid registration. Registration of 15 data sets which include CT, MR and PET images for brain, head and neck, cervix, prostate and lung was performed utilizing a rigid body registration with normalized mutual information as the similarity measure. The resulting registrations were classified as good or bad by visual inspection. The resulting registrations were also classified using our MSR method. The results of our MSR method agree with the classification obtained from visual inspection for all cases (p < 0.02 based on ANOVA of the good and bad groups). The proposed method is independent of the registration algorithm and similarity measure. It can be used for multi-modality image data sets and different anatomic sites of the patient.     

Activation of the NF-kB pathway downregulates TFF-1 in gastric carcinogenesis

Trefoil factor 1 (TFF1) is expressed in the normal superficial epithelium of the stomach and is implicated in the maintenance of gastric epithelial structure and function. During gastric carcinogenesis, in which pro-inflammatory cytokines play a crucial role, its expression level decreases suggesting a role as tumor suppressor factor. We have compared expression of TFF1 in gastric mucosa from cancer patients, in which several degrees of inflammatory infiltrate are present, with that in normal mucosa from non-cancer patients without infiltrating inflammatory cells. TFF1 is less expressed in the superficial gastric epithelium from cancer patients than in that from normal individuals in which the nuclear factor (NF)-κB pathway is not activated. We analyzed TFF1 expression in ex vivo samples of gastric mucosa from cancer patients, and in MKN45 gastric cancer cell line after exposure to proinflammatory cytokines interleukin (IL)-1β or tumor necrosis factor (TNF)-α, that activate the NF-κB pathway. We found that IL-1β and TNF-α activate the NF-κB pathway, as reflected in the nuclear expression of p65 and the activation of p-IκBα, and downregulate TFF1 expression after 1 or 2 h of exposure. Moreover, cells in the superficial gastric epithelium in ex vivo samples co-expressed TFF1/p65 at cellular level, whereas tumor cells did not. In summary, downregulation of TFF1 expression during gastric neoplastic transformation is associated with activation of the NF-κB pathway through IL-1β or TNF-α, but other regulatory mechanisms might also be involved.