Retinal function and PKC alpha expression after focal laser photocoagulation

Purpose

To examine the effects of focal laser photocoagulation on general and local retinal function and to relate electrophysiological findings with changes in protein kinase C (PKC) alpha expression.

Methods

Twelve rabbits were treated with 70 spots of laser photocoagulation in the central cone-rich retina. The operated eyes were investigated with electroretinography (full-field ERG and multifocal electroretinography, mfERG) preoperatively and at 1, 3, and 5 weeks after surgery. The expression of PKC alpha was examined at all three time points using immunohistochemistry, and PKC alpha mRNA levels were quantified using real-time polymerase chain reaction (PCR). Immunohistochemistry for glial fibrillary acidic protein (GFAP) and hematoxylin and eosin staining was employed to monitor the extent and dynamics of the morphological response.

Results

The full-field ERG revealed a significant increase in b-wave amplitudes derived from the isolated rod response (blue light) at all three time points after surgery (p?Conclusions Focal laser treatment in the rabbit eye induces local and wide-spread alterations in both rod- and cone-mediated retinal function in the form of supernormal b-wave amplitudes in the full-field ERG and increased latency in the mfERG. The electrophysiological abnormalities are accompanied by a progressive down-regulation of the PKC alpha isoenzyme in rod bipolar cells, reaching far beyond the treated area. PKC alpha is down-regulated directly by impaired protein synthesis, and also possibly indirectly by protein consumption related to GFAP up-regulation. The results indicate that focal laser photocoagulation interferes with PKC-alpha-mediated inhibitory regulation of inner retinal signal transmission.     

Vestibular myogenic potentials evoked by air-conducted stimuli at safe acoustic intensity levels retain optimal diagnostic properties for superior canal dehiscence syndrome

Background: Vestibular-evoked myogenic potential (VEMP) is commonly conducted with air-conducted (AC) stimuli whose intensity may exceed the prudential levels of acoustic exposure in susceptible subjects.

Objectives: To determine the diagnostic accuracy of AC VEMP for superior canal dehiscence syndrome (SCDS) at lowered acoustic stimulation levels.

Material and methods: VEMP was tested in 10 SCDS patients and in 10 age/sex matched control subjects. VEMP were recorded on cervical muscles (cVEMP) and extraocular muscles (oVEMP) in response to short AC tone bursts at 500, 1000 and 2000?Hz delivered at 80?dB nHL (103?dB peSPL). Parameters of interest were the response amplitude and the frequency tuning.

Results: VEMP evoked by AC stimuli at safe acoustic stimulation levels did effectively separate SCDS patients from healthy controls. The separation was optimal at all the frequencies tested, however 500?Hz resulted the best VEMP tuning frequency, especially at oVEMP.

Conclusions: Lowering the AC stimulation to the levels compatible with testing of patients susceptible to acoustic exposure didn’t affect the VEMP diagnostic properties for SCDS.

Significance: SCDS may be screened by VEMP even among subjects susceptible for acoustic exposure.     

An outbreak of legionnaires disease caused by long-distance spread from an industrial air scrubber in Sarpsborg, Norway.

BACKGROUND: On 21 May 2005, the Norwegian health authorities were alerted by officials from a local hospital that several recent patients had received the diagnosis of legionnaires disease; all patients resided in 2 neighboring municipalities. We investigated the outbreak to identify the source and to implement control measures. METHODS: We interviewed all surviving case patients and investigated and harvested samples from 23 businesses with cooling towers and other potential infection sources. The locations of the businesses and the patients' residences and movements were mapped. We calculated attack rates and risk ratios among people living within various radii of each potential source. Isolates of Legionella pneumophila were compared using molecular methods. RESULTS: Among 56 case patients, 10 died. The case patients became ill 12-25 May, resided up to 20 km apart, and had not visited places in common. Those living up to 1 km from a particular air scrubber had the highest risk ratio, and only for this source did the risk ratio decrease as the radius widened. Genetically identical L. pneumophila serogroup 1 isolates were recovered from patients and the air scrubber. The air scrubber is an industrial pollution-control device that cleans air for dust particles by spraying with water. The circulating water had a high organic content, pH of 8-9, and temperature of 40 degrees C. The air was expelled at 20 m/s and contained a high amount of aerosolized water. CONCLUSIONS: The high velocity, large drift, and high humidity in the air scrubber may have contributed to the wide spread of Legionella species, probably for >10 km. The risk of Legionella spread from air scrubbers should be assessed.     

Control of suture hole bleeding after aortic valve replacement by application of BioGlue during circulatory arrest

Bleeding from suture holes in aortic valve replacement (AVR) may represent a difficult problem especially if the aortic wall is friable. We describe a case in which suture hole bleeding after AVR was present at the posterior aortic wall close to the pulmonary artery. Following several attempts to suture the leak using felt pledget armed prolene sutures, deep hypothermic circulatory arrest was induced and BioGlue in combination with Tabotamp was applied for successful sealing of the bleeding source.     

Repair of erosions in rheumatoid arthritis does occur. Results from 2 studies by the OMERACT Subcommittee on Healing of Erosions

The committee was charged with determining whether healing of erosions in rheumatoid arthritis (RA) occurs. Two exercises were performed: The first asked the committee members, as a panel of experts, to express agreement or disagreement with the presence of improvement and features of bone reaction to injury in images submitted by members as examples of healing. The second presented panel members with 28 pairs of serial images, 14 chosen to illustrate progression and 14 chosen to illustrate repair. Agreement was tested on 8 items: global judgment on which image in the pair was better, relative size of the erosion in the 2 images, judgment on which image was first, presence and extent of sclerosis, cortication, filling-in, remodeling, and reconstituting normal structure. Our results showed good agreement, among the 15 respondents, on global assessment of which image was better and which image showed the smaller erosion. Correct assignment of sequence was only slightly better than expected by chance (in 65% of the cases). Agreement was poor regarding the presence of morphologic features of bone repair. A majority of a panel of experts agreed on which 2nd images in a set of paired, serial images represented improvement and which showed progression based on global assessment of which was better and on size of erosion. Features of bone repair were not distinctive and did not enable the panel to deduce the correct sequence of the serial images. This study provides evidence that repair of bone damage in RA does occur, resulting in some degree of improvement, which was recognized by a majority of a panel of experts.     

Functional capacity vs side effects: treatment attributes to consider when individualising treatment for patients with rheumatoid arthritis

Clinical Rheumatology - Individualisation of rheumatoid arthritis (RA) treatment needs to take account of individual patients’ preferences to increase patient-centeredness in treatment...     

Evaluation of the Paradoxical Sphincter Contraction by a Strain/Squeeze Index in Constipated Patients

PURPOSE One finding in patients with constipation is the paradoxical puborectalis contraction, i.e. , activation of the sphincter muscles during straining instead of relaxation. The aims of this study were to evaluate the importance of needle placement in sphincter-electromyography and to evaluate a strain/squeeze index in constipated patients and control subjects. METHODS We investigated consecutively 194 constipated patients and 16 control subjects with integrated electromyography during straining and squeezing and calculated a strain/squeeze index. The examination was performed in the puborectalis and in the external anal sphincter muscle through hook-electrodes. RESULTS There was a strong correlation between indices in the puborectalis muscle and in the external anal sphincter muscle (r = 0.70–0.80, P < 0.001). Forty-seven patients (24 percent) had a mean index of greater than 50 compared with none in the control group (P = 0.01). Mean overall index in patients was 24 (range, 0–306) vs. 18 (range, 0–45) in controls (P = 0.12). Patients with an index greater than 50 had impaired rectal evacuation (P < 0.001), increased threshold for urge (P < 0.05), and tended to have fewer stools (P = 0.06). CONCLUSION Quantification of paradoxical contraction in the puborectalis and external anal sphincter with a strain/squeeze index differentiates patients in whom paradoxical activity may be a cause of constipation. An index above 50 may be of pathologic significance. Correlations between activity in the puborectalis and external anal sphincter muscle were strong which suggests that investigation in one of them is sufficient. Reprints are not available.     

Normocomplementaemic urticarial vasculitis: effective treatment with omalizumab

We report two patients with normocomplementaemic urticarial vasculitis with impressive response to omalizumab. This contrasts recent reports on hypocomplementaemic urticarial vasculitis syndrome, highlighting the need for clinical trials of omalizumab in normocomplementaemic urticarial vasculitis.