MR imaging, flow and motion.

The present work is intended as a nonmathematical review of the role of flow and motion in nuclear magnetic resonance (MR) imaging. A historical review of MR flow measurement techniques is given, followed by a short overview of flow models in vitro and in vivo. The theory behind the influence of motion on the modulus and phase MR signal information is discussed and effects such as washin/washout, flow-induced signal void, phase offset, and phase dispersion are defined. A simple approach to the concept of MR angiography is given, and methods for quantitative flow measurements such as the phase mapping technique, are surveyed. Aspects of the measurement of diffusion and microcirculation are given, and finally, an overview of the role of MR flow imaging in present and future clinical application is given.     

Endothelial cell implantation and survival within experimental gliomas.

The delivery of therapeutic genes to primary brain neoplasms opens new opportunities for treating these frequently fatal tumors. Efficient gene delivery to tissues remains an important obstacle to therapy, and this problem has unique characteristics in brain tumors due to the blood-brain and blood-tumor barriers. The presence of endothelial mitogens and vessel proliferation within solid tumors suggests that genetically modified endothelial cells might efficiently transplant to brain tumors. Rat brain endothelial cells immortalized with the adenovirus E1A gene and further modified to express the beta-galactosidase reporter were examined for their ability to survive implantation to experimental rat gliomas. Rats received 9L, F98, or C6 glioma cells in combination with endothelial cells intracranially to caudate/putamen or subcutaneously to flank. Implanted endothelial cells were identified by beta-galactosidase histochemistry or by polymerase chain reaction in all tumors up to 35 days postimplantation, the latest time examined. Implanted endothelial cells appeared to cooperate in tumor vessel formation and expressed the brain-specific endothelial glucose transporter type 1 as identified by immunohistochemistry. The proliferation of implanted endothelial cells was supported by their increased number within tumors between postimplantation days 14 and 21 (P = 0.015) and by their expression of the proliferation antigen Ki67. These findings establish that genetically modified endothelial cells can be stably engrafted to growing gliomas and suggest that endothelial cell implantation may provide a means of delivering therapeutic genes to brain neoplasms and other solid tumors. In addition, endothelial implantation to brain may be useful for defining mechanisms of brain-specific endothelial differentiation.     

Mycobacterium gastri arthritis: septic arthritis due to Mycobacterium gastri in a patient with a renal transplant

We describe an 18-year-old man with a renal transplant who developed septic metacarpophalangeal arthritis due to Mycobacterium gastri. He had several episodes of crystal induced synovitis, and treatment with intraarticular steroids was complicated 3 months later by iatrogenic septic arthritis. Appropriate treatment based on in vitro drug susceptibility was successful. This seems to be the first case of articular infection and the third report of human infection caused by this atypical mycobacteria.     

Endocrine organ failure due to systemic AA-amyloidosis

We describe a patient with panhypopituitarism and adrenal insufficiency associated with systemic AA-amyloidosis caused by tuberculosis. This case demonstrates the ongoing process of amyloidosis, despite a presumed cure for the tuberculosis more than 30 years previously. Difficulties in recognizing clinical symptoms and interpreting laboratory data in a patient on regular haemodialysis are discussed.     

Comparison of Health and Safety Executive and Cumbrian birth cohort studies of risk of leukaemia/non-Hodgkin's lymphoma in relation to paternal preconceptional irradiation.

In 1993, a case-control study by the Health and Safety Executive (HSE) assessed the risk of leukaemia and non-Hodgkin's lymphoma (LNHL) among children of fathers employed at the Sellafield nuclear installation in relation to paternal preconceptional irradiation (PPI). It concluded that the statistical association between risk of LNHL and PPI was confined to children born in the village of Seascale, where the dose-response was extremely high and very significant. In contrast, in 2002, a Cumbrian birth cohort study, investigating largely the same cases, concluded that this statistical association was not significantly different among children born inside and outside Seascale and estimated the dose-response inside Seascale to be much lower. This review makes a detailed comparison of the two studies, considering their design, data and analyses. The differences between their findings are due to: (i) differences in the distribution of offspring-years which are differential with respect to dose category and Seascale birth status, (ii) a non-Seascale high-dose case included in the Cumbrian but not the HSE study, (iii) differences between analyses using categorical and continuous PPI dose and (iv) the presence of Seascale controls with PPI over 200 mSv in the Cumbrian but not the HSE study.     

Mother's education and perinatal problems in Finland.

This study using nationwide data expands a previous study from one area in Finland. The purpose was to study how perinatal problems (mortality, short gestation, low birthweight and low Apgar scores) vary by mother's social class, which is measured by level of education. Outcomes of all births in the 1987 Medical Birth Register were linked to the 1988 National Education Register with gives the estimated number of years of completed education. In unadjusted analyses, the lowest educational groups (less than 9 years) had the worst results for outcomes other than neonatal mortality. Results in the two highest educational groups (greater than or equal to 13 and 12 years of education) were similar and if anything, better in the second highest group. Excluding twins and adjusting for confounding variables (age, parity, county, urbanization of residence) by logistic regression analysis did not alter the results much. Adjustment for possible mechanisms correlated with social class (marital status, smoking, time of first antenatal visit) decreased the higher occurrence of low birthweight infants in the low educational groups. Reported previous miscarriages were more common in the higher educational groups. Based on the available background characteristics one would expect to have found the usual social gradient in perinatal problems to have persisted between the two highest educational groups. Further studies on factors causing the plateau in the gradient between these groups might be useful.     

Search for retrovirus in the chronic fatigue syndrome.

AIM: To examine peripheral blood and skeletal muscle from patients with chronic fatigue syndrome for exogenous retrovirus. METHODS: Blood samples from 30 patients and muscle biopsy specimens of 15 patients were examined for retroviral sequences by DNA extraction, polymerase chain reaction (PCR), and Southern blotting hybridisation. Sera were examined for human foamy virus by western immunoblotting and indirect immunofluorescence techniques. RESULTS: No differences between the patient and control populations was found for any of the PCR primer sets used (gag, pol, env, and tax regions of HTLV I/II). An endogenous gag band was observed in both the patient and control groups. All sera were negative for antibody to human foamy virus. CONCLUSION: The results indicate that there is no evidence of retroviral involvement in the chronic fatigue syndrome.     

Factors affecting renal allograft function in long-term recipients.

The natural history of renal allograft function in long-term recipients is not known. To characterize renal allograft function and the factors that affect it, we reviewed the records of all patients who received a renal allograft at the University of Wisconsin between 1965 and 1981 and selected those who had annual data on renal function for at least 10 years. We identified 155 patients--78 with living-related donors and 77 with cadaveric donors. All patients were adults receiving azathioprine and prednisone. Renal function was estimated by calculated creatinine clearances (Ccr), which correlated well with measured 24-hour creatinine clearances. The creatinine clearance data for each patient were plotted versus time. In 73% of patients, the creatinine clearance increased for several years before reaching a peak value. After the peak, the creatinine clearance declined in a linear manner. Stepwise regression analyses indicated that allografts from cadaveric donors had a greater increase in creatinine clearance from the value at year 1 to the peak than allografts from living-related donors (0.35 +/- 0.25 v 0.21 +/- 0.23 mL/s [21.4 +/- 15.0 v 12.7 +/- 13.8 mL/min]; P less than 0.001). The average time to reach the peak value of creatinine clearance was longer in cadaveric allografts (6.8 +/- 3.5 v 4.6 +/- 4.0 years; P less than 0.001). Postpeak, the rate of decline in creatinine clearance was faster in cadaveric allografts than in living-related ones (0.06 +/- 0.05 v 0.04 +/- 0.04 mL/s/yr [3.50 +/- 2.99 v 2.55 +/- 2.16 mL/min/yr]; P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)     

Review article: the dietary management of Crohn's disease

Enteral feeding has been shown to be as effective as primary therapy for Crohn's disease, but it requires high patient motivation, may be unpalatable and is expensive. However, in adolescents with growth failure and when corticosteroid therapy is contra-indicated or has failed, it may become the treatment of choice. Furthermore, dietary therapy allows circumvention of the adverse side-effects of repeated courses of steroids.
A number of different hypotheses have been proposed to explain the effect of enteral feeds but none has reached universal acceptance. Prospective trials suggest that the exclusion of whole protein is not necessary. Comparison of feeds with differing composition suggests that a low fat content increases efficacy and various explanations have been offered. The reduction of colonic bacterial load may also be important.
Because symptoms of Crohn's disease may be provoked by eating, there is a risk of falsely attributing symptoms to specific foodstuffs. However, in many individuals foods can be identified which affect disease activity, and their exclusion leads to prolongation of disease remission. Dietetic supervision during food testing is important to avoid detrimental effects on nutrient and micronutrient intake.