Measurements of neutron radiation in aircraft

Radiation environment is a complex mixture of charged particles of the solar and galactic origin, as well as of secondary particles created in an interaction of galactic cosmic particles with the nuclei of the Earth's atmosphere. A radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. In order to measure a neutron component of the cosmic radiation, we investigated a few combinations of a track etch detector (CR-39, LR-115) with a plastic converter or boron foil. Detector calibration was performed on neutrons coming from the nuclear reactor, as well as in the CERN-EU high-energy Reference Field (CERF) facility. From November 2007 to September 2008, the neutron dose equivalent was measured by the track detectors during five aircraft flights, in the north geographical latitude from 21° to 58°; the respective average dose rate, determined by using the D-4 detector (CR-39/B), was Ḣ(n)=5.9 μSv/h. The photon dose rate, measured by the electronic dosimeter RAD-60 SE, had the average value of Ḣ(f)=1.4 μSv/h.

Hepatitis C infected hemodialysis and renal transplant patients with elevated α-glutathione S-transferase have increased risk for liver damage

Patients on hemodialysis (HD) and renal transplant recipients (RT) have a high prevalence of HCV infection. Theaimof our study was to determine the prevalence of HCV-RNA in the anti-HCV positive patients and to compare the biochemical parameters of PCR(+) and PCR(−) subgroups.Methods:The 525 sera were screened for anti-HCV. HCV-RNA was detected by polymerase chain reaction (PCR) and liver enzymes [SGOT, SGPT, GGT,α-glutathione S-transferase (GST)] were measured.Results:Active viraemia was found only in 187 of 289 (65%) seropositive HD patients in contrast to 53 of 53 (100%) of seropositive RT patients. Significantly increased (p<0.05) GST values (9.9 μg/l) were found in the PCR(+) subgroups compared to GST levels (2.7 μg/l) of the PCR(−) subgroups. Elevated GST concentration was found in 80% (208/251) of PCR(+) patients. The measured enzymes were not elevated in HCV infected patients. Six percent of HD and 11% of RT patients were screened before seroconversion. Diagnostic sensitivity (80%) and specificity (79%) of GST were calculated as good for early liver damage caused by HCV. In contrast, the sensitivity of the measurement of other liver enzymes were very weak (SGOT: 8%; SGPT: 10%; GGT: 42%).Conclusion:The significantly higher viraemia of the RT subgroup could be related to the immunosuppressive therapy. Increased GST level may be a useful indicator of tissue damage during HCV infection. If HCV infection is suspected, PCR and GST measurement should be performed, even if anti-HCV result is negative.

The iQ200 Microscopic Analyzer is valuable tool for evaluation of urinary sediment at transplanted patients

The value of urinary cytology in the diagnosis of different pathological conditions in renal transplantation is particularly important. Manual microscopic urinalysis is a high-volume procedure that currently requires significant labour.

Objective: To automate the sediment evaluation and to make this more accurate using the Iris Diagnostics Automated Urine Microscopy Analyzer (iQ200). Our goal was to compare the manual and automated microscopic data to apply iQ200 in renal function monitoring.

Method: The iQ200 uses digital imaging and Auto Analyte Recognition software to classify urine constituents into 12 analyte categories and quantitatively report.

Results: We determined cut-off values of urine particles in every category, which correlated well with manual microscopic results. The iQ200 was more sensitive for pathological casts than manual microscopic analysis. iQ200 helped the operator to differentiate between isomorphic and dismorphic erythrocytes and between lymphocytes and granulocytes, too. Every pathological constituent could be recognized, which is very important for early recognition of renal impairment, graft rejection and urinary tract infection.

Conclusions: The iQ200 system automatically classifies 12 particles, significantly reducing the need for additional sample preparation, manual microscopic review achieving a high degree of standardization in urinalysis.

[Clinical experience with cold-preservation of venous and arterial allografts. long-term outcomes]

INTRODUCTION

Venous and arterial allografts extend the possibilities of peripheral arterial disease as well as vascular prosthesis infections treatment.

MATERIAL AND METHODS

Between 10/1997 and 1/2009 we used 112 allogeneic vessels (30 arteries, 82 veins) in 104 patients. Venous allografts were used for 82 reconstructions in 75 patients (M/F 41/34, aged 41-85 years, median 66 years) with critical limb ischemia and no suitable autogenous venous material. Arterial allografts were used in 9 patients (M/F 8/1, aged 56-77 years, median 63 years) with aortoiliac prosthetic infections or mycotic abdominal aortic aneurysms and in 20 transplanted patients (M/F 11/9, aged 32-67 years, median 56 years) with aortoiliac atherosclerotic disease.

RESULTS

Patients survival rate after allovenous bypasses was 92% at 1 year and 78% at 3 years. Limb salvage rate was 67% at 1 year and 53% and 3 years. Secondary patency rate was 48% at 1 year and 27% at 3 years. Patient survival rate after alloarterial bypasses was 86% at 1 year and 69% at 3 years. No signs of arterial grafts aneurysmal formation and no need for secondary intervention of any arterial reconstruction was observed during the follow up period in any patient after alloarterial transplantation.

CONCLUSIONS

Cold-stored venous and arterial allografts are suitable alternative conduits for limb salvage procedures, vascular prosthesis infections as well as for arterial reconstructions in transplanted patients.

The positive effect of immunosuppression on adaptation of venous allografts to arterialisation in rats

OBJECTIVES AND DESIGN

We investigated whether immunosuppression was necessary for transplanted allogeneic veins to adapt to arterialisation. We used a transplant rat model with or without immunosuppression.

MATERIAL AND METHODS

Iliolumbar veins from Lewis (LEW) or Brown-Norway (BN) rats were transplanted into the abdominal aorta of isogeneic (LEW to LEW; group A) or allogeneic (BN to LEW; groups B and C) rats. Group C had daily intramuscular injections of 0.2mgkg(-1) FK506. Light microscope evaluations of grafts were performed at 30 days following transplantation. We determined the presence of endothelial cells, the intensity of intimal proliferation and the degree of infiltration by Lewis major histocompatibility complex (MHC) class II positive, CD4-positive and CD8-positive cells into the adventitia.

RESULTS

Groups A and C displayed similar results in intimal thickness (12.7+/-7.0microm vs. 15.0+/-8.4 mum, respectively) and degree of adventitial infiltration by MHC class II positive (16.6+/-7.5 vs. 14.6+/-6.2, respectively), CD8-positive (0.8+/-1.7 vs. 1.8+/-2.6, respectively) and CD4-positive (12.5+/-7.7 vs. 5.8+/-4.6, respectively) cells. In contrast, allogeneic rats without immunosuppression (group B) showed infiltration of host immunocompetent cells and destruction of the venous wall with no histological signs of arterialisation.

CONCLUSION

Immunosuppressive therapy is necessary for venous allograft adaptation to arterialisation in rats.

Intermittent pneumatic compression acts synergistically with manual lymphatic drainage in complex decongestive physiotherapy for breast cancer treatment-related lymphedema

The application of intermittent pneumatic compression (IPC) as a part of complex decongestive physiotherapy (CDP) remains controversial. The aim of this study was to investigate whether the combination of IPC with manual lymph drainage (MLD) could improve CDP treatment outcomes in women with secondary lymphedema after breast cancer treatment. A randomized study was undertaken with 13 subjects receiving MLD (60 min) and 14 receiving MLD (30 min) plus IPC (30 min) followed by standardized components of CDP including multilayered compression bandaging, physical exercise, and skin care 10 times in a 2-week-period. Efficacy of treatment was evaluated by limb volume reduction and a subjective symptom questionnaire at end of the treatment, and one and two months after beginning treatment. The two groups had similar demographic and clinical characteristics. Mean reductions in limb volumes for each group at the end of therapy, and at one and two months were 7.93% and 3.06%, 9.02% and 2.9%, and 9.62% and 3.6%, respectively (p < 0.05 from baseline for each group and also between groups at each measurement). Although a significant decrease in the subjective symptom survey was found for both groups compared to baseline, no significant difference between the groups was found at any time point. The application of IPC with MLD provides a synergistic enhancement of the effect of CDP in arm volume reduction.

[Transarterial chemoembolization in hepatocellular carcinoma]

INTRODUCTION

Hepatocelullar carcinoma (HCC) is the fifth most common cancer in the world. It mostly occurs in patients with cirrhosis. In the Czech Republic, about 250 new cases are reported per year. Surgery, i.e. liver resection or transplantation, as the only potentially curable method is possible in 15-20% of them. For the rest, palliative treatment is indicated. This includes ablative methods (radiofrequency ablation, alcoholization), transarterial chemoembolization (TACE), systemic chemotherapy or biological treatment by sorafenib. TACE is method of choice in patients unsuitable for surgery and ablative treatment. Another indication is embolization of HCC before liver transplantation to prevent tumour progression. In combination with other methods, down staging of the tumour and curable treatment afterward is possible.

AIMS

To assess the outcome of transarterial chemoembolisation in patients with hepatocellular carcinoma.

METHODS

Between 2004-2008 we performed 30 TACE. Of that number, 28 TACE were performed in 20 patients with HCC. We super selectively catheterized the tumour via arteria femoralis and used Doxorubicin with Lipiodol as embolic material. In follow up, we carried out laboratory studies and CT.

RESULTS

We have not noticed any major complications. Post-embolization syndrome with fever, nausea and right upper quadrant pain occurred after 10 TACE (33%). One-, two- and three years survival of the patients was 53%, 40% a 20%.

CONCLUSION

TACE is safe method prolonging patients' survival with unresectable HCC. For the correct treatment of HCC, its concentration to cancer centres and the cooperation between multiple specialists is necessary.

[One-year survival outcomes in patients with pancreatic head and portomesenteric veins resection]

INTRODUCTION

Hemipancreatoduodenectomy is a standard technique for surgical management of pancreatic head carcinomas. However, so far, mesenteric and/or portal vein resections have not been commonly indicated. This original report presents one-year survival outcomes in a group of operated subjects.

METHODOLOGY

From 7/2005 to 7/2008, 13 pancreatic resections with concomitant resection of the mesenteric or portal vein were performed in the IKEM Transplant Surgery Clinic. The study objective was to assess the perioperative complications and 30-day mortality rates, and the overall survival period.

RESULTS

The study group included 13 patients, 8 males and 5 females, the mean age was 66 (48 to 85) years. Concomitantly, resection of the portal vein (6x) or the superior mesenteric vein (3x), or of the both veins (4x) was performed. In 11 subjects of this patient group, the time period between the surgical procedure and the assessment was over a year. During the portomesenteric reconstruction phase, end-to-end anastomoses were performed in eight subjects, and the resected vein was replaced with the internal jugular vein in two subjects. In three subjects, the venous wall excision site was closed using a simple defect suture. Out of the study group, 5 subjects were surviving at 12 months. Three patients exited due to their primary diagnosis and the fourth one for internal complications two months after the procedure.

CONCLUSION

The authors belive that hemipancreatoduodenectomy with concomitant resection of portomesenteric veins should become a standard treatment method in indicated patients, performed in specialized centres.

Reduced insight in bipolar I disorder: neurofunctional and neurostructural correlates: a preliminary study

BACKGROUND

To correlate measures of insight for own psychopathology to structural and functional brain imaging findings in 21 patients with DSM-IV bipolar I disorder.

METHODS

Insight was assessed using the Scale to Assess Unawareness of Mental Disorder (SUMD). Resting single photon emission computed tomography (SPECT) and computed tomography (CT) was conducted in patients and 21 normal comparison subjects matched for age, gender and handedness.

RESULTS

Reduced general insight and symptom awareness, but not symptom attribution, were significantly related to cortical and subcortical atrophy, respectively. No correlations between SPECT and insight measures were identified.

LIMITATIONS

Limited sample size and the use of resting state SPECT.

CONCLUSIONS

General and symptom awareness were related to measures of brain atrophy but not to neurofunctioning as measured by SPECT. Future research should consider the structure and function of specific cortical regions, including the frontal and parietal cortices.

[Pancreatic resection for metastatic renal cell carcinoma]

BACKGROUNDS

Late metastases of renal cell carcinoma (RCC) are quite common. However, metastases in the pancreas are rare. Between 2004-2008 the Department of transplantation surgery of the institute of clinical and experimental medicine performed 87 pancreatic resections for tumour. From this, metastasis of RCC was histologically verified in four cases.The aim of this study was to summarize in the form of brief case reports our experience with the surgical treatment of pancreatic metastasis of RCC.

OBSERVATION

The interval from nephrectomy to the occurrence of pancreatic metastasis was 10, 11, 15 and 16 years. All patients were examined to exclude metastatic generalization. Surgical treatment was: one total pancreatectomy, two subtotal pancreatectomies and one caudal resection. Two patients had solitary pancreatic metastasis, one had two metastases and one had multiple metastatic lesions. No complications were observed in the postoperative period. All patients are living with survival time of 7, 23, 26 and 52 months. None of them has signs of recurrence of the primary disease.

CONCLUSION

The follow up in patients with a history of RCC should be lifelong. Considering the low response of RCC and its metastases to oncological treatment, pancreatic resection is a safe method with a low rate of complications in patients with RCC metastases limited only to the pancreas and detected in time.

[Primary retroperitoneal tumor--extraadrenal paraganglioma--a case review]

Primary retroperitoneal tumors are extremely rare tumors of this location. The authors present a case review of a 53-year-old patient operated for unexplained retroperitoneal neoplasm. No complications were recorded during the postoperative course and histology demonstrated extraadrenal paraganglioma structures, ranked among the above neoplasms. Preoperative hypertension subsided postoperatively, following the active neuroendocrinne tumor removal. The aim of this work is to present clinical and histopathological characteristics of this rare retroperitoenal neoplasm.

Cosmic radiation dose in aircraft--a neutron track etch detector

Cosmic radiation bombards us at high altitude by ionizing particles. The radiation environment is a complex mixture of charged particles of solar and galactic origin, as well as of secondary particles produced in interaction of the galactic cosmic particles with the nuclei of atmosphere of the Earth. The radiation field at aircraft altitude consists of different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard ATR 42 and A 320 aircrafts (flight level of 8 and 11 km, respectively) was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter. The estimated occupational effective dose for the aircraft crew (A 320) working 500 h per year was 1.64 mSv. Other experiments, or dose rate measurements with the neutron dosimeter, consisting of LR-115 track detector and boron foil BN-1 or 10B converter, were performed on five intercontinental flights. Comparison of the dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level showed that the neutron component carried about 50% of the total dose. The dose rate measurements on the flights from the Middle Europe to the South and Middle America, then to Korea and Japan, showed that the flights over or near the equator region carried less dose rate; this was in accordance with the known geomagnetic latitude effect.

Thymus and myasthenia gravis: antigen processing in the human thymus and the consequences for the generation of autoreactive T cells

Peptides displayed by antigen presenting cells in the thymus shape the T cell repertoire. We investigated the antigen processing machinery of the MHC class II presentation pathway and describe the differential expression of lysosomal proteases in compartments of the thymus and the peripheral lymphoid tissue. Overexpression of certain proteases found in the thymus and thymoma associated with myasthenia gravis is likely to affect tolerance induction and may promote the generation autoreactive CD4(+) T helper cells.

Insight, symptoms and neurocognition in bipolar I patients

BACKGROUND

Level of insight and its relationship to clinical variables and neurocognitive functions was assessed in bipolar I patients.

METHODS

Verbal memory, executive functioning, sustained attention, general intelligence and other neurocognitive functions were compared between 37 chronic in- and outpatients and 31 matched normal controls. Detailed psychiatric interviews were completed to define the level of symptomatology and psychosocial functioning. Insight was assessed by the Scale to Assess Unawareness of Mental Disorder (SUMD).

RESULTS

Seventy percent of the patients were classified as having impaired insight. Prevalence of impaired insight was 47% and 94% in remitted and symptomatic patients, respectively. Symptomatic patients scored significantly below remitted patients on insight and neurocognition. Illness and symptom unawareness were related to overall level of symptoms, measures of memory, conceptual ability and right hand psychomotor speed and accuracy. Misattribution of symptoms and signs was correlated to visuomotor speed and visuospatial performance in addition to affective symptoms and thought disturbance.

CONCLUSIONS

Our findings support the hypothesis that impaired insight and other neurocognitive dysfunctions were present in a large percentage of cases among symptomatic as well as remitted bipolar patients. This may be of clinical relevance and raises important questions about the course and outcome of the illness.