Magnetic resonance spectroscopy and perfusion weighted imaging as predictors for tumor response to gamma knife radiosurgery: A single center experience

Objective

To test the hypothesis that hemodynamic and metabolic characteristics of intracranial neoplasms detected with magnetic resonance spectroscopy and perfusion weighted imaging are efficient predictors of tumor response to radiosurgery.

Methods

Fifty-four patients with 59 intracranial neoplasms, who underwent evaluation with echoplanar PW and MRS imaging prior to gamma knife radiosurgery were selected for this retrospective analysis. The mean irradiation dose was 13.76 Gy. The mean follow up after GNR constituted 24 months. Predictive diagnostic accuracy was calculated with standard formulas. The association of tumor response to radiosurgery with pretherapeutic MRI parameters was estimated using the Mann–Whitney U test.

Results

Significant association was found between the perfusion and hemodynamic parameters of intracranial neoplasms and the outcome of GKR. Diagnostic accuracy of multimodel MRI was 89% among low grade and 65% among high grade neoplasms. The overall accuracy was 81%. Normalized rCBV, choline, NAA and lipid contents and Chol/cr and NAA/cr were statistically different between low and high grade neoplasms (p < 0.001).

Conclusion

MR perfusion and spectroscopic results provided information that were predictive of the outcome of radiosurgery in this patient pool, increased the diagnostic accuracy of conventional MRI in defining tumor type and grade and may play an important role in pre-therapeutic planning for radiosurgery.     

Predicting final infarct size using acute and subacute multiparametric MRI measurements in patients with ischemic stroke

PURPOSE: To identify early MRI characteristics of ischemic stroke that predict final infarct size three months poststroke. MATERIALS AND METHODS: Multiparametric MRI (multispin echo T2-weighted [T2W] imaging, T1-weighted [T1W] imaging, and diffusion-weighted imaging [DWI]) was performed acutely (<24 hours), subacutely (three to five days), and at three months. MRI was processed using maps of apparent diffusion coefficient (ADC), T2, and a self-organizing data analysis (ISODATA) technique. Analyses began with testing for individual MRI parameter effects, followed by multivariable modeling with assessment of predictive ability (R(2)) on final infarct size. RESULTS: A total of 45 patients were studied, 15 of whom were treated with tissue plasminogen activator (tPA) before acute MRI. The acute DWI and DWI-ISODATA mismatch lesion size, and the interactions of ADC, T2, and T2W imaging lesion with tPA remained in the final multivariable model (R(2) = 70%). A large acute DWI lesion or DWI < ISODATA lesion independently predicted increase in the final infract size, with predictive ability 68%. Predictive ability increased (R(2) = 83%) when subacute MRI parameters were included along with acute DWI, DWI-ISODATA mismatch, and acute T2W image lesion size by tPA treatment interaction. Subacute DWI > acute DWI lesion size predicted an increased final infarct size (P < 0.01). CONCLUSION: Acute-phase DWI and DWI-ISODATA mismatch strongly predict the final infarct size. An acute-to-subacute DWI lesion size change further increases the predictive ability of the model.     

Biliary disease after liver transplantation: the experience of the King Faisal Specialist Hospital and Research Center, Riyadh

BACKGROUND AND AIM: The biliary tract has been referred to as the "Achilles heel" of liver transplantation. The aim of this study was to document the frequency, clinical presentation and management of biliary complications after liver transplantation in the King Faisal Specialist Hospital and Research Center (KFSH&RC), Riyadh, Saudi Arabia. METHODS: The liver transplant clinic at KFSH&RC has registered and followed 220 patients (150 male and 70 female patients; age 40.6 +/- 18.6 years; pediatric 33, adult 187) during the period from 1987 to June 2003. A total of 235 transplants were carried out on these patients. Cadaveric liver transplants had been carried out on 202 patients, non-heart beating liver transplant in three patients, live donor liver transplants in 11 and split transplant in four. Biliary reconstruction was duct-to-duct anastomosis in 147 patients and Roux-en-Y in 73. Biliary complications were suspected on clinical and biochemical parameters and confirmed using imaging techniques. RESULTS: Forty patients (18.2%) developed 53 biliary complications. These included bile leak in 16, strictures in 25, calculi in eight, and sphincter of Oddi dysfunction and possible recurrence of primary sclerosing cholangitis in the donor duct in two patients each. Bile leaks were observed in the early postoperative period (median period 30 days, range 1-150 days, 95% confidence interval [CI] 8-51). Leakage occurred at the anastomotic site in 13 patients. Patients presented with bilious drainage (n = 6), abdominal pain at T-tube removal (n = 3), fever (n = 2), sepsis (n = 1), dyspnea (n = 1) and abnormal liver tests (n = 3). Eleven patients had intra-abdominal bilious collections. Two patients were treated conservatively, eight patients had ultrasound-guided aspiration of biloma, five had biliary stenting at endoscopic retrograde cholangiopancreatography and two patients needed surgery. There were four deaths, two of which were related to bile leak, one patient was left with permanent external biliary drainage and four patients had biliary strictures in the follow-up period. Biliary strictures occurred at a median period of 360 days (range 4-2900 days; 95% CI 50-670) after the transplant. Hepatic artery thrombosis caused biliary strictures in three, while 21 strictures were localized to the anastomotic site. Biliary strictures presented with elevated liver tests in five patients, progressive cholestasis in five, cholangitis (with septicemia in five) in 11, abdominal pain in two and acute pancreatitis in three patients. Repeat sessions of endoscopic or percutaneous dilatation and stenting (mean sessions 4.4/patient, range 3-7) were attempted in 20 patients to relieve strictures, with success in only nine patients. Seven patients had surgery. Four patients with biliary strictures died. Biliary calculi developed late in the follow-up period and had the appearance of biliary casts in five and sludge in three patients. Eleven (27.5%) patients with biliary disease died compared with 35 (19.4%) patients without biliary disease. CONCLUSIONS: Biliary complications occurred in 18.2% of patients after liver transplantation and included biliary leak and biliary strictures with or without calculi. Management involved a combination of endoscopic, radiologic and operative procedures. Biliary complications caused considerable morbidity and mortality in liver transplant patients.     

Predictors of edge stenosis following sirolimus-eluting stent deployment (a quantitative intravascular ultrasound analysis from the SIRIUS trial)

To study the interaction of the sirolimus-eluting stent and vessel margins, we analyzed the intravascular ultrasound parameters in 317 edges of 167 stents having 18 edge stenoses at 8 months of follow-up from the SIRIUS trial. Of the baseline parameters, a larger reference percentage of plaque area and a larger edge stent area/reference minimum lumen area were associated with edge stenosis in the sirolimus-eluting stent cohort compared with the incidence of edge stenosis in the bare metal stent cohort. Thus, full lesion coverage and matching the stented segment properly to the adjacent segment using intravascular ultrasound guidance may improve sirolimus-eluting stent implantation efficacy further.     

Effect of gender on treatment, resource utilization, and outcomes in congestive heart failure in Quebec, Canada

This study assessed whether a gender gap exists in therapy, procedure use, and outcomes in patients who have a new diagnosis of congestive heart failure (CHF) at the population level. The Quebec hospital discharge database was linked with the physician and drug claims databases to identify a cohort of patients who had a diagnosis of CHF (code 428 in the International Classification of Diseases, Ninth Revision) between January 1998 and December 2002. There were 16,017 men and 16,622 women. Women who had CHF were older (78 +/- 11 vs 73 +/- 11 years, p <0.001), had more hypertension (41% vs 28%, p <0.001) and hyperlipidemia (18% vs 14%, p <0.001) but less frequent myocardial infarction (19% vs 25%, p <0.001). Women were less likely to see a cardiologist (30% vs 34%, p <0.001) and required a longer hospital stay (12.0 +/- 14.8 vs 10.6 +/- 13.3 days, p <0.001). During the first year after a first CHF hospitalization, women were less like to have an assessment of left ventricular function (61% vs 65%, p <0.001), diagnostic cardiac catheterization (11% vs 15%, p <0.001), and revascularization procedure (4% vs 6%, p <0.001). Women were less likely to be prescribed an angiotensin-converting enzyme inhibitor (60% vs 66%) and more likely to be prescribed a beta blocker (38% vs 34%). Women and men had similar yearly numbers of rehospitalizations for CHF (1.4 +/- 1.0 vs 1.5 +/- 1.0) and emergency room visits (1.7 +/- 1.2 vs 1.8 +/- 1.3). The adjusted risk of death was minimally higher in men than in women (hazard ratio 1.06, 95% confidence interval 1.03 to 1.1, p <0.01). Thus, despite less frequent cardiologist assessment, fewer cardiac-related procedures, and less frequent use of standard medical therapy, clinical outcomes in women and men who had CHF were similar.     

Mosquito nets and the poor: can social marketing redress inequities in access?

Treated mosquito nets are a practical malaria control tool. However, implementation of efficient delivery mechanisms remains a challenge. We investigated whether social marketing of treated mosquito nets results in decreased equity in rural Tanzania, through household surveys before the start of a social marketing programme and 3 years later. About 12,000 household heads were asked about ownership of nets and other assets including a tin roof, radio, or bicycle. A socio-economic status score was developed for each household. Net ownership was calculated for households in each quintile of this score, from poorest to least poor. In 1997, about 20% of the poorest households and over 60% of the least poor households owned a mosquito net. Three years later, more than half of the poorest households owned a net, as did over 90% of the least poor: the ratio of net ownership among the poorest to least poor increased from 0.3 in 1997 to 0.6 in 2000. Social marketing in the presence of an active private sector for nets was associated with increased equity.     

The influence of selenium supplementation on postpartum thyroid status in pregnant women with thyroid peroxidase autoantibodies

CONTEXT: Pregnant women who are positive for thyroid peroxidase antibodies [TPOAb(+)] are prone to develop postpartum thyroid dysfunction (PPTD) and permanent hypothyroidism. Selenium (Se) decreases thyroid inflammatory activity in patients with autoimmune thyroiditis. OBJECTIVE: We examined whether Se supplementation, during and after pregnancy, influences the thyroidal autoimmune pattern and function. DESIGN: This was a prospective, randomized, placebo-controlled study. SETTING: The study was conducted in the Department of Obstetrics and Gynecology and Department of Endocrinology. PATIENTS: A total of 2143 euthyroid pregnant women participated in the study; 7.9% were TPOAb(+). INTERVENTIONS: During pregnancy and the postpartum period, 77 TPOAb(+) women received selenomethionine 200 microg/d (group S1), 74 TPOAb(+) women received placebo (group S0), and 81 TPOAb(-) age-matched women were the control group (group C). MAIN OUTCOME MEASURES: We measured the prevalence of PPTD and hypothyroidism. RESULTS: PPTD and permanent hypothyroidism were significantly lower in group S1 compared with S0 (28.6 vs. 48.6%, P<0.01; and 11.7 vs. 20.3%, P<0.01). CONCLUSION: Se supplementation during pregnancy and in the postpartum period reduced thyroid inflammatory activity and the incidence of hypothyroidism.     

Combined semi-nested polymerase chain reaction and heteroduplex analysis for detecting monoclonality of IgH rearrangement in patients with follicular lymphoma

A new, sensitive method combining seminested polymerase chain reaction (PCR) and heteroduplex analysis was used to detect follicular lymphoma (FL) cells in peripheral blood. Based on the detection of IgH rearrangement in DNA from peripheral blood leukocytes, the method demonstrated the presence of monoclonal B cells in FL patients with high frequency.     

Gut Permeability and Intestinal Mucins,Invertase, and Peroxidase in Control and Diabetes-Prone BB Rats Fed Either a Protective or a Diabetogenic Diet

This study deals with the enteropathy recently identified in diabetes-prone BB rats (BBdp). Diabetes-resistant BB rats (BBc) and BBdp rats were fed from days 32–39 onward either a protective diabetes-retardant hydrolyzed casein diet (HC) or a plant-based diabetogenic (NTP) diet. The NTP diet decreased body weight and plasma insulin in BBc and BBdp rats. The BBdp rats displayed low intestinal invertase and increased intestinal peroxidase activity. In the BBdp rats fed the HC diet, the mucin content 30–35 cm below the pylorus was higher and the gut permeability lower than in the other three rat groups. There was a significant inverse correlation between gut permeability and the insulinogenic index in the BBdp rats fed the HC or NTP diet. Thus, in BBdp rats, the HC diet somehow prevents the increase in gut permeability and the decrease in the insulinogenic index otherwise found in some of these diabetes-prone animals.     

Compliance to hepatitis B vaccination and subsequent development of seroprotection among health care workers of a tertiary care center of Saudi Arabia

BACKGROUND: There is lack of reliable data on compliance to hepatitis B virus (HBV) vaccine and development of seroprotective levels of antibodies among health care workers (HCWs) from the countries with high HBV endemicity such as Saudi Arabia. This study aimed to assess the compliance with HBV vaccine and subsequent levels of seroprotection among HCWs of a large tertiary care center of the Eastern Province of Saudi Arabia. METHODS: All the HCWs (n = 1302) involved in direct patient care, including 374 (28.7%) physicians, 619 (47.6%) nurses, and 309 (23.7%) technicians, were enrolled for the study. Those having antibody to hepatitis B surface antigens (anti-HBs) levels less than 10 mIU/mL were advised to take 3 doses of yeast-derived recombinant HBV vaccine at 0, 1, and 6 months of 1 mL (20 microg/mL) in the deltoid muscle. Blood samples were checked for anti-HBs antibody levels by enzyme immunoassay during the initial screening of HCWs and 3 months after the third dose of HBV vaccine. The group of physicians included 34.5% (129/374) of consultants, 16.8% (63/374) of specialists, and 48.6% (182/374) of residents. RESULTS: An overall HBV vaccine compliance rate of 71.6% (932/1302) was observed among HCWs including that of 79.5% (492/619) among nurses, 78.3% (242/309) among technicians, and 52.9% (198/374) among physicians. Thus, physicians recorded the lowest compliance (OR, 3.211; 95% CI, 2.259-4.567; P < .0001) to HBV vaccine. Among physicians, the lowest compliance of 42.3% (77/182) was observed in residents (OR, 3.690; 95% CI, 1.067-3.703; P < .0001). The overall seroprotection after vaccination was achieved in 92.2% of the compliant HCWs, and 7.8% of them failed to mount adequate response to HBV vaccine. Nonresponders included mainly the physicians (OR, 2.229; P = .05)-consultants in particular (OR, 3.476; P < .0001). The mean age of nonresponders was higher than those who mounted an adequate anti-HBs response (46.7 +/- 6.3 vs. 32.2 +/- 3.3 years OR, 1.845; 95% CI, 0.999-3.414; P < .05). CONCLUSIONS: Poor compliance to HBV vaccine among physicians--residents in particular-is an issue of immense concern, which demands close examination and identification of the specific action that needs to be taken to enhance the uptake of the vaccine by this target population.