Serial magnetic resonance spectroscopy reveals a direct metabolic effect of cediranib in glioblastoma

Proton magnetic resonance spectroscopy is increasingly used in clinical studies of brain tumor to provide information about tissue metabolic profiles. In this study, we evaluated changes in the levels of metabolites predominant in recurrent glioblastoma multiforme (rGBM) to characterize the response of rGBM to antiangiogenic therapy. We examined 31 rGBM patients treated with daily doses of cediranib, acquiring serial chemical shift imaging data at specific time points during the treatment regimen. We defined spectra from three regions of interest (ROI)--enhancing tumor (ET), peritumoral tissue, and normal tissue on the contralateral side (cNT)--in post-contrast T1-weighted images, and normalized the concentrations of N-acetylaspartate (NAA) and choline (Cho) in each ROI to the concentration of creatine in cNT (norCre). We analyzed the ratios of these normalized metabolites (i.e., NAA/Cho, NAA/norCre, and Cho/norCre) by averaging all patients and categorizing two different survival groups. Relative to pretreatment values, NAA/Cho in ET was unchanged through day 28. However, after day 28, NAA/Cho significantly increased in relation to a significant increase in NAA/norCre and a decrease in Cho/norCre; interestingly, the observed trend was reversed after day 56, consistent with the clinical course of GBM recurrence. Notably, receiver operating characteristic analysis indicated that NAA/Cho in tumor shows a high prediction to 6-month overall survival. These metabolic changes in these rGBM patients strongly suggest a direct metabolic effect of cediranib and might also reflect an antitumor response to antiangiogenic treatment during the first 2 months of treatment. Further study is needed to confirm these findings.

MRI-measured water mobility increases in response to chemotherapy via multiple cell-death mechanisms

Numerous pre-clinical and clinical reports have demonstrated that the MRI-measured apparent diffusion coefficient of water (ADC) increases early in the response to a wide variety of anti-cancer therapies. It has been proposed that this increase in ADC generally results from an increase in the tumor extracellular volume fraction leading to a greater degree of unrestricted water motion. Furthermore, an increase in extracellular volume has been ascribed to the cell shrinkage that occurs early in the process of programmed cell death. However, other modes of death can be initiated soon after beginning therapy. These other modes of death include mitotic catastrophe and necrosis, and may also involve changes in the fraction of water with unrestricted motion. This work examines whether MRI-measured ADC is altered in response to therapies that induce cell death via non-apoptotic mechanisms and correlates ADC changes with cell death modalities regionally within the tumor. Apoptotic responses were limited to the tumor periphery in apoptosis-proficient tumors. Apoptosis was not observed in deficient tumors. Mitotic catastrophe was observed after treatment at the periphery and deeper into the tumor. Necrosis was the predominant response in the center of the tumor. ADC changes were moderate in the periphery and larger in the center. The results indicate that early and significant changes in ADC can occur in concert with mitotic catastrophe and lytic necrosis in the absence of apoptosis. Hence, changes in ADC may be a generalized measure of cytotoxic response to chemotherapy.

Combination therapy with an ACE inhibitor and an angiotensin receptor blocker for diabetic nephropathy: a meta-analysis

AIMS

Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) prevent the progression of diabetic nephropathy (DN). Studies suggest that combination renin-angiotensin-aldosterone system (RAAS)-inhibiting therapy provides additive benefit in DN. However, these studies are small in size. We performed a meta-analysis of studies investigating combination therapy for DN.

METHODS

Studies were identified through a search of medline, embase, cinahl and the Cochrane Database. All trials involving combined ACEI and ARB for slowing progression of DN were included. The primary end point was 24-h urinary protein excretion. Blood pressure, serum potassium and glomerular filtration rate (GFR) were secondary end points.

RESULTS

In the 10 included trials, 156 patients received ACEI + ARB and 159 received ACEI only. Most studies were 8-12 weeks in duration. Proteinuria was reduced with ACEI + ARB (P = 0.01). This was associated with significant statistical heterogeneity (P = 0.005). ACEI + ARB was associated with a reduction in GFR [3.87 ml/min (7.32-0.42); P = 0.03] and a trend towards an increase in serum creatinine (6.86 micromol/l 95% CI -0.76-13.73; P = 0.09). Potassium was increased by 0.2 (0.08-0.32) mmol/l (P < 0.01) with ACEI + ARB. Systolic and diastolic blood pressure were reduced by 5.2 (2.1-8.4) mmHg (P < 0.01) and 5.3 (2.2-8.4) mmHg (P < 0.01), respectively.

CONCLUSIONS

This meta-analysis suggests that ACEI + ARB reduces 24-h proteinuria to a greater extent than ACEI alone. This benefit is associated with small effects on GFR, serum creatinine, potassium and blood pressure. These results should be interpreted cautiously as most of the included studies were of short duration and the few long-term studies (12 months) have not demonstrated benefit.

Medical care utilization by AFDC recipients under reformed Medicaid

As Medicaid moves toward a system of managed care, Aid for Families with Dependent Children (AFDC) recipients often are assigned to an organization that assumes responsibility for managing their annual receipt of health care. This study reports the results of an investigation into the patterns of medical care utilization by AFDC recipients and their children under reformed Medicaid. The issues explored include whether or not medical care utilization patterns vary by race, and if there are identifiable factors that determine the utilization patterns of AFDC recipients and their children. We conclude that racial differences in medical care utilization do exist for AFDC recipients, but not for their children. Policy makers involved in reforming Medicaid should recognize that certain cohorts continue to exhibit undesirable medical care utilization patterns, and implement measures to rectify this situation.

Managing the quality effort in a health care setting: an application

Recent marketplace realities and trends have forced health care institutions to adopt strategic orientations that stress a customer focus. Central to such strategic orientations is the effective utilization of service quality practices and philosophies. Toward that end, this research offers health care institutions an affordable methodology. A real-life application of the rapid assessment methodology (RAM) in a health care operational setting is presented. Finally, a framework to guide the implementation of the RAM methodology is outlined and explored.

In vitro karyotypic and immunophenotypic characterisation of primitive neuroectodermal tumours: similarities to malignant gliomas

Monoclonal antibody (Mab) mediated immunotherapy of brain tumours requires the identification of tumour-restricted cell surface antigens. We have characterised four primitive neuroectodermal tumours, which included pineoblastoma, medulloblastoma and ependymoblastoma cultures, that demonstrated in vitro evidence of malignant behaviour (anchorage-independent growth and nu/nu xenograft tumour formation). The cytogenetic findings ranged from normal G-banded and Q-banded karyotypes through mixed near-diploid/hyperdiploid. These cultures resembled the cell surface immunophenotypic spectrum of malignant gliomas. They were distinguished from normal glia in vitro by the expression of restricted fetal mesenchymal, neuronal, myoblastic, melanocytic, epidermal, chondrocytic, lymphoid and epithelial antigens. Certain antigens appeared sufficiently represented among central nervous system (CNS) neoplasms to afford potential targets for Mab-mediated immunotherapy.

High-level penicillin-resistant gonococcal infections in Port Elizabeth

The prevalence of penicillin-resistant Neisseria gonorrhoeae in black men with acute urethritis at two clinics for sexually transmitted diseases in Port Elizabeth was assessed during the latter half of 1986. Gonococcal aetiology was confirmed in 80% of 290 patients. Penicillinase-production was detected in 4.3% culture-positive cases, while intermediate penicillin resistance was demonstrated in another 28 isolates (13.9%). At least two strains exhibited high-level penicillin resistance without producing beta-lactamase. All isolates tested were susceptible to tetracycline and spectinomycin. The emergence of penicillin-resistant gonococci throughout southern Africa will require new approaches to the treatment of acute urethritis in men.

Human Yersinia enterocolitica infection in the eastern Cape. A report on 18 cases and a review of yersiniosis in the RSA

Yersinia enterocolitica infections with a wide spectrum of clinical presentations have been reported in South Africa. An additional 18 cases were encountered in the eastern Cape region during the period May 1982 - December 1984. Y. enterocolitica isolates comprised 1% of 1,634 faecal examinations performed by the Microbiology Department of the South African Institute for Medical Research in Port Elizabeth during this period, compared with isolation rates of 5.1% for shigellae, 3.7% for salmonellae and 1.3% for Campylobacter jejuni. The majority of Y. enterocolitica infections were in children who presented with diarrhoea and only 2 systemic cases were documented. Although more cases were seen in summer there was no distinct seasonal incidence and this may be attributed to the even climatic conditions prevailing in the region.