Blue light exposure in vitro causes toxicity to trigeminal neurons and glia through increased superoxide and hydrogen peroxide generation.

Today the noxiousness of blue light from natural and particularly artificial (fluorescent tubes, LED panels, visual displays) sources is actively discussed in the context of various ocular diseases. Many of them have an important neurologic component and are associated with ocular pain. This neuropathic signal is provided by nociceptive neurons from trigeminal ganglia. However, the phototoxicity of blue light on trigeminal neurons has not been explored so far. The aim of the present in vitro study was to investigate the cytotoxic impact of various wavebands of visible light (410-630 nm) on primary cell culture of mouse trigeminal neural and glial cells. Three-hour exposure to narrow wavebands of blue light centered at 410, 440 and 480 nm of average 1.1 mW/cm2 irradiance provoked cell death, altered cell morphology and induced oxidative stress and inflammation. These effects were not observed for other tested visible wavebands. We observed that neurons and glial cells processed the light signal in different manner, in terms of resulting superoxide and hydrogen peroxide generation, inflammatory biomarkers expression and phototoxic mitochondrial damage. We analyzed the pathways of photic signal reception, and we proposed that, in trigeminal cells, in addition to widely known mitochondria-mediated light absorption, light could be received by means of non-visual opsins, melanopsin (opn4) and neuropsin (opn5). We also investigated the mechanisms underlying the observed phototoxicity, further suggesting an important role of the endoplasmic reticulum in neuronal transmission of blue-light-toxic message. Taken together, our results give some insight into circuit of tangled pain and photosensitivity frequently observed in patients consulting for these ocular symptoms.

Gastric cancer with liver metastasis.

Surgical treatment of gastric cancer with liver metastasis (GCLM) is currently a frequent topic of discussion at professional surgical symposia. There is a low number of patients and a lack of large clinical multi-center studies describing the benefits of this treatment approach. The article describes a patient with GCLM, growing through stomach wall serosa, invading the spleen hilum, distal part of pancreas with metastasis to S7 of the right liver lobe. The patient had total gastrectomy performed with D2 lymphadenectomy, distal pancreatectomy with splenectomy, resection of diaphragm and RFA of the metastatic lesion in S7 of the liver. Post-surgery course was free of complications, followed by adjuvant chemotherapy. 2 years after the surgery, the patient is in full remission, free of any relapse. Liver resection or RFA is not commonly used in the gastric cancer with liver metastasis (GCLM). At present, there is no direct marker available to define the degree of biological aggressiveness of the tumor (indicating or contra-indicating the surgical treatment), therefore we are left to rely on indirect prognostic factors: cancer invasion in the gastric wall serosa, presence of 3 and more liver metastases, size of metastasis exceeding 50 mm (Fig. 2, Ref. 13).

[Central cervical dissection of lymph nodes in the management of differentiated thyroid carcinoma--our experience]. / Centrálna krcná disekcia lymfatických uzlín v liecbe diferencovaného karcinómu stítnej zl'azy--na e skúsenosti.

INTRODUCTION: Total thyroidectomy (TTE) with central compartment lymphonodes (LU) dissection remains a standard procedure in the treatment of differentiated thyroid carcinomas. METHODOLOGY: The retrospective study assessed a group of patients undergoing primary or secondary procedures in our clinic. PATIENT GROUP: From 01.01. 2005 to 31. 07. 2007, a total of 50 patients underwent primary procedures, TTE with dissection of central compartment lymphonodes was performed in 18 patients, 58 patients were reoperated for relapses of the disorder. In the primary procedures, the central compartment lymphonodes were affected with increased rate, proportionally to a T-stage of the disorder 28% (T1), 52 (T2), 58% (T3). Multifocal carcinoma was associated with a high risk, where metastatic lymphadenopathy occured in 53% of the cases. In the reoperated subjects, relapses of the disorder were recorded in 78% of the patients in their central compartment lymphonodes and their thyreoglobulin levels decreased. Out of 126 patients, paresis of the nervus laryngeus reccurens was recorded in 4 subjects (3.1%) and postoperative hypoparathyreosis in 14 subjects (11%). CONCLUSION: Dissection of lymphonodes is a standard part of the surgical management of differentiated carcinomas, providing local control of the disease. 78% of the relapses were located within the central compartment. Risk and complication rates correspond to those reported in total thyroidectomy.

Effect of hyaluronidase on albumin diffusion in lung interstitium.

Albumin diffusion measured in an isolated segment of rabbit lung interstitium with a radioactive tracer ((125)I-albumin) technique was independent of albumin concentration and similar to the free diffusion of albumin in water (Qiu et al, 1998. J Appl Physiol 85: 575-583). We studied the effect of hyaluronidase on the diffusion of albumin. Isolated rabbit lungs were inflated with silicon rubber by way of airways and blood vessels, and two chambers were bonded to the sides of a approximately 0.5-cm thick slab enclosing a vessel with an interstitial cuff. One chamber was filled with 2 g/dl albumin solution containing (125)I-albumin and 0.02 g/dl hyaluronidase. Unbound (125)I was removed from the tracer by dialysis before use. The other chamber filled with Ringer's solution was placed within a NaI(Tl) scintillation detector. Diffusion of tracer was measured continuously for 120 h. Albumin diffusion coefficient (D) and interstitial area (A) were obtained by fitting the tracer-time curve with the theoretical solution of the equation describing one-dimension diffusion of a solute across a membrane. D averaged 5.2 x 10(-7) cm(2)/s for albumin diffusion with hyaluronidase, 20% less than that measured previously without hyaluronidase. Hyaluronidase had no effect on A. Results indicated an interaction between albumin and interstitial hyaluronan that was the opposite of the steric effect on albumin excluded volume measured in solution.

Simulating patients with Parallel Health State Networks.

The American Board of Family Practice is developing a computer-based recertification process to generate patient simulations from a knowledge base. Simulated patients require a stochastically generated history and response to treatment, suggesting a Monte Carlo-like patient generation process. Knowledge acquisition experiments revealed that description of a patient's overall health as a node in a Monte Carlo model was difficult for domain experts to use, severely limited knowledge reusability, and created a plethora of awkwardly defined health states. We explored a model in which patients traverse several parallel health state networks simultaneously, so that overall health is a vector describing the current nodes from every Parallel Network. This model has a reasonable biological basis, more easily defined data, and greatly improved reuse potential, at the cost of more complex simulation algorithms. Experiments using osteoarthritis stages, weight classification, and absence or presence of gastric ulcers as three Parallel Networks demonstrate the feasibility of this approach to simulating patients.

A formal model of family medicine.

BACKGROUND: The American Board of Family Practice is developing a computer-based recertification process. An optimal implementation requires a formal model of family medicine, which will become the basis for a knowledge base. DESIGN: The proposed model of family medicine contains six entities: Population, Record, Agents of Change, Health States, Findings, and Courses of Action. The model illustrates 15 important relations between entities. For instance: Health States Lead to Health States, and Findings Associate with Health States. These two relations describe natural history, manifestations of disease, and the effects of medical interventions and risk factors. Because time is such an important aspect of primary care, nearly all numeric data are represented as graphs of possible values over time, called Patterns, which include details about periodicity. Patterns and other aspects of the model provide a means of describing covariance between observations, such as the influence of height on weight. RESULTS: The model reflects many family practice activities and suggests some formal descriptions of family practice. For instance, diagnostic activities focus largely on classifying early or short segments of Patterns in Findings. Most medical interventions attempt to alter either the probability distributions in a Lead-to relation or the impact of a Finding. CONCLUSION: The proposed model of family medicine could find uses in many applications, including computer-based tests, medical records, reference systems, and decision support tools.

[Determination of chlorinated pesticides in food and in human adipose tissue]. / Stanovení reziduí chlórovaných pesticidü v pozivatinách a lidských tukových tkáních.

Residues of chlorinated pesticides in feed for laying hens, in eggs, poultry organs, potatoes, flour, and human fat tissues were determined by means of gas chromatography using electron recording detector. Further the amount of chlorinated hydrocarbon residues in potatoes from various parts of the South Moravian Region was stated. HCH amounts in human fat tissues recorded in Czechoslovakia were higher than in some West European countries, DDT content being, however, on the same level.