Semiautomatic brain region extraction: a method of parcellating brain regions from structural magnetic resonance images

Structural MR imaging has become essential to the evaluation of regional brain changes in both healthy aging and disease-related processes. Several methods have been developed to measure structure size and regional brain volumes, but many of these methods involve substantial manual tracing and/or landmark identification. We present a new technique, semiautomatic brain region extraction (SABRE), for the rapid and reliable parcellation of cortical and subcortical brain regions. We combine the SABRE parcellation with tissue compartment segmentation [NeuroImage 17 (2002) 1087] to produce measures of gray matter (GM), white matter (WM), ventricular CSF, and sulcal CSF for 26 brain regions. Because SABRE restricts user input to a few easily identified landmarks, inter-rater reliability is high for all volumes, with all coefficients between 0.91 and 0.99. To assess construct validity, we contrasted SABRE-derived volumetric data from healthy young and older adults. Results from the SABRE parcellation and tissue segmentation showed significant differences in multiple brain regions in keeping with regional atrophy described in the literature by researchers using lengthy manual tracing methods. Our findings show that SABRE is a reliable semiautomatic method for assessing regional tissue volumes that provides significant timesavings over purely manual methods, yet maintains information about individual cortical landmarks.

Survival after proton-beam irradiation of uveal melanomas

PURPOSE

To evaluate the independent prognostic factors for survival, metastasis, local recurrence, and enucleation in patients who had undergone proton-beam therapy for posterior uveal melanomas.

DESIGN

Interventional case series.

METHODS

In this retrospective study, 224 consecutive incident cases were treated at the Biomedical Cyclotron Centre (Nice, France) from June 1991 to December 1997. Overall, metastasis-free, local recurrence-free, and enucleation-free survival rates were calculated according to the Kaplan-Meier method using the log-rank test. The multivariate prognostic analysis was performed using the Cox proportional hazards model.

RESULTS

The 5-year overall survival rate was 78.1% (SE: 3.7%). A largest basal tumor diameter (LTD) below 10 mm and female sex were independently associated with a better prognosis. The 5-year metastasis-free survival rate was 75.6% (SE: 3.6%). Only an LTD above 10 mm and ciliary body involvement were independently associated with metastasis. Ten patients (4.5%) had a local recurrence, which was correlated with the risk of metastasis (P =.045). The 5-year enucleation-free survival rate was 69.6% (SE: 4.0%). Once again, an LTD below 10 mm and female sex were predictive of a better prognosis.

CONCLUSION

Our results with proton-beam therapy correspond to those reported in the literature. This treatment strategy is safe and yields predictably good results. In addition to the two independent prognostic factors for survival and metastasis, namely LTD and ciliary body involvement, sex also had a significant impact in our case series, but the clinical relevance of this finding is unknown.

Survival, anatomic, and functional long-term results in choroidal and ciliary body melanoma after ruthenium brachytherapy (15 years' experience with beta-rays)

PURPOSE

To analyze survival, radiation-related complications, local recurrence, enucleation, and visual acuity after ruthenium-106 irradiation of malignant uveal melanoma.

DESIGN

Retrospective study.

METHODS

A total of 213 patients treated with ruthenium-106 brachytherapy between 1983 and 1995. End point rates were estimated by life tables, and prognostic factors by Cox proportional hazards regression. Main outcome measures were survival rate, radiation-related maculopathy, radiation-related vascular occlusion, local tumor recurrence, enucleation, and visual acuity (<20/100 at 3 years).

RESULTS

At 5 and 10 years, survival was 82% (standard error [SE] 2.7%) and 72% (SE 3.4%), local recurrence 21.7% (SE 3.0%) and 24.3% (SE 3.2%), and enucleation 18.0% (SE 2.7%) and 19.2% (SE 2.8%), respectively. Sixty-one patients showed maculopathy (29%), 36 retinal vascular occlusion (17%), in 33 local recurrence (16%), and 38 enucleation (18%). Age and large tumor diameter were independently associated with survival (P <.0001 and P <.0075, respectively). Age below 40 and melanoma located posteriorly were significant risk factors for maculopathy (P <.0085 and P <.0004, respectively) and vascular occlusion (P <.0415 and P <.0114, respectively). Diameter and Bruch membrane rupture were significant predictors (P <.0032 and P <.0390, respectively) of local recurrence. Visual acuity <20/100 was observed in only 26 of 97 (27%) cases of anterior but 34 of 42 (81%) of posterior tumor (P <.001).

CONCLUSION

Although percentage tumor recurrence was high, survival was comparable to series using other treatments. Radiation-related complication rates were acceptable, especially for anterior tumors. Ruthenium therapy can, therefore, be recommended for small and medium-sized tumors with anterior location.

Estimating the relative risk of developing melanoma in INK4A carriers

Estimation of the relative risk of cancer due to rare germline mutations using population-based epidemiological techniques is challenging, since studies with very large numbers of subjects are required. In this pilot study using a novel study design, we evaluated the role of INK4A mutations in melanoma by comparing patients with multiple primary melanomas to those with single primaries. Patients were ascertained from the Surgery and Dermatology Clinics at Memorial Sloan-Kettering Cancer Center and at the Yale University Pigmented Lesion Clinic. Subjects completed a questionnaire covering risk factors for melanoma and were tested for INK4A mutations. Five (8%) of 65 patients with multiple primaries had a mutation, compared with none of 88 patients with single primaries (P=0.03). Examination of other factors, such as number of nevi on the arms of the patients, fair skin, hair and eye colour, and other phenotypic characteristics associated with the risk of melanoma, demonstrates that these factors exhibit higher prevalence in the multiple primary cases than in the single primaries. These results provide evidence of the utility of the new study design in evaluating the impact of rare but highly penetrant cancer risk factors.

Clinico-mycological Profile of Superficial Mycosis in a Hospital in North-East India

A clinico-mycological study of superficial mycoses was conducted on 121 cases (98 males and 23 females). Direct microscopy by KOH mount and culture was undertaken to isolate the fungal pathogen in each case. The commonest age group involved was 21-30 years (39.6%). Dermatophytosis was the commonest clinical presentation (70.5%), followed by candidiasis (20.5%) and Pityriasis versicolor (9.0%). The commonest dermatophytosis was Tinea pedis (29.2%), followed by T cruris (26.2%). The commonest dermatophyte isolated was Trichophyton tonsurans (20.5%), followed by T rubrum (8.7%). Cultures grew a high proportion of non dermatophyte moulds (34%), of which Cladosporium spp (37.1%) was the commonest mould isolated. Total KOH positivity rate was 53.3% and total culture positivity rate was 79.1%. Our study revealed a variant local dermatophyte flora, a clinical pattern typical to our work environment in the Defence Services and a high isolation of yeasts and NDM.

Nature and duration of protective immunity to bluetongue virus infection

Genetic engineering offers a variety of approaches to producing viral vaccines. An exciting advance in this field is the ability to construct virus-like particles (VLPs) that resemble their natural counterparts but lack genetic information. To develop a rationally designed vaccine for bluetongue disease of sheep that is caused by virus (BTV), we have synthesised individual BTV proteins and BTV-like particles (VLPs and CLPs) using baculovirus expression systems and insect cell cultures. A series of clinical trials were undertaken using these proteins and particles in BTV-susceptible sheep. The accumulated data obtained from these studies are: (i) the two surface proteins when used in high doses (approximately 100 microg/dose) could afford complete protection in sheep against virulent virus challenge; (ii) in contrast, only 5-10 microg of VP2 of a related virus, African horse sickness virus (AHSV) afforded protection in horses against virulent virus challenges when vaccinated in the presence of appropriate adjuvant; (iii) vaccination with as little as 10 microg VLPs (consisting of all four major proteins) gave long lasting protection (at least for 14 months) against homologous BTV challenge; (iv) cross-protection was also achieved depending on the challenge virus and amounts of antigen used for vaccination and (v) limited vaccination trials with CLPs (containing only two highly conserved internal proteins) afforded partial (with slight fever) protection against homologous and heterologous virus challenges. Since CLPs are conserved across the twenty four BTV serotypes, CLPs could have potential for a candidate vaccine that may at least mitigate the disease and inhibit virus spread. In summary, VLPs and CLPs offer completely safe and efficacious vaccines as their particles are devoid of any detectable amount of insect, baculovirus proteins or nucleic acids and thus pose no potential adverse effects.

Patterns of outcome and prognostic factors in primary large-cell lymphoma of the testis in a survey by the International Extranodal Lymphoma Study Group

PURPOSE

To determine clinical features and patterns of outcome of primary testicular diffuse large B-cell lymphomas (DLCL).

PATIENTS AND METHODS

A retrospective international survey of 373 patients with primary testicular DLCL.

RESULTS

Most patients presented with localized disease (stage I to II), and the median age at diagnosis was 66 years (range, 19 to 91 years). Anthracycline-based chemotherapy was administered to 255 patients (68%), and prophylactic intrathecal chemotherapy was given to 68 patients (18%); 133 patients (36%) received prophylactic scrotal radiotherapy. Median overall survival was 4.8 years, and median progression-free survival was 4 years. The survival curves showed no clear evidence of a substantial proportion of cured patients. A favorable international prognostic index score (IPI), no B-symptoms, the use of anthracyclines, and prophylactic scrotal radiotherapy were significantly associated with longer survival at multivariate analysis. However, even for patients with stage I disease and good-risk IPI, the outcome seems worse than what was reported for DLCL at other sites. At a median follow-up of 7.6 years, 195 patients (52%) had relapsed. Extranodal recurrence was reported in 140 cases. Relapses in CNS were detected in 56 patients (15%) up to 10 years after presentation. A continuous risk of recurrence in the contralateral testis was seen in patients not receiving scrotal radiotherapy.

CONCLUSION

Testicular DLCL is characterized by a particularly high risk of extranodal relapse even in cases with localized disease at diagnosis. Anthracycline-based chemotherapy, CNS prophylaxis, and contralateral testicular irradiation seem to improve the outcome. Their efficacy is under evaluation in a prospective clinical trial.

Tumour inhibitory activity of chicory root extract against Ehrlich ascites carcinoma in mice

The tumour-inhibitory effect of an ethanolic extract of chicory root was studied against Ehrlich ascites carcinoma in mice; significant results were obtained at doses from 300 to 700 mg/kg.

Effect of age, period of diagnosis and birth cohort on large bowel cancer incidence in a well-defined French population, 1976-1995

The objective of this study was to present trends in colorectal cancer incidence by sex and subsite in a well-defined French population. All of the 4486 large bowel cancer cases registered between 1976 and 1995 in the Burgundy registry of digestive tract cancers was included in this study. Time trends in colorectal cancer incidence were analysed over the 1976-95 period. The effects of age, period and cohort were evaluated using a log-linear Poisson model. The incidence rates for right colon cancer increased over time: + 21.6% (95% CI: + 13.5; + 29.7) per 5-year period in males and +10.4% (95% CI: + 3.4; + 17.3) in females. Left colon cancer rates increased in males (+ 10.6% 95% CI: + 4.6; + 16.6). Left colon cancer in females and rectal cancer incidence rates did not significantly change. Between the 1901 cohort to the 1941 cohort, estimated cumulative risks for right colon cancer increased sharply. The increase was less marked for left colon and the cumulative risk for rectal cancer remained almost stable. Temporal trends were different by subsites and sexes. In conclusion, our results confirm the existence of different trends in colorectal cancer incidence between subsites and sexes. These differences probably reflect aetiological distinctions.

Amifostine reduces mucosal damage after high-dose melphalan conditioning and autologous peripheral blood progenitor cell transplantation for patients with multiple myeloma

High-dose melphalan (HDM) has been adopted as standard therapy in the treatment of multiple myeloma. This treatment is associated with non-selective cytotoxicity, causing oral mucositis as the major non-hematological side-effect. Amifostine is a cytoprotector which prevents toxicity induced by anticancer therapy. We prospectively compared two groups of patients who either received (group A, n = 21) or did not receive (group B, n = 20) amifostine (740 mg/m(2)) before HDM (200 mg/m(2)) followed by autologous peripheral blood progenitor cell transplantation. The occurrence of severe oral mucositis was significantly decreased in group A in comparison to group B (33% vs 65%, P < 0.05). Six patients in group A required opioid analgesic therapy during a mean period of 4.8 days as compared to eight patients for 6.5 days in group B (P = NS). Delayed vomiting was less frequent in group A (43% vs 70%, P = 0.07) and significantly less severe in group A (grade 2-4) vomiting: two patients vs nine patients, P < 0.02). No difference was observed between the two groups in either hematological toxicity after HDM or in response rate. Grade I emesis was the only immediate side-effect observed after amifostine administration. We conclude that amifostine can reduce mucositis induced by HDM.

Interethnic marriage: identifying the second generation in Australia

"Studies in Australia show that an increasing proportion of the population have ancestors from more than one country. Evidence regarding differences in the marriage patterns of first and second generation migrants has been restricted in scope as published marriage registration data includes only birthplace of partners. Marriage registration records include information about the birthplace of parents of partners, but is available only through specially produced tabulations. Changes in the census for 1986 and 1991 make it possible to identify the second generation in households, and this article examines the use of census data as an alternative to marriage registration records in tracing changes in intermarriage patterns and differences between urban and rural areas."

Nondestructive analysis of the transverse structure of novel optical fibers by third-harmonic-generation microscopy

We demonstrate the suitability of the third-harmonic-generation technique as a new nonlinear microprobe for nondestructive determination of the index profile of optical fibers. Photonic bandgap (Bragg-type) and air-silica microstructure (ASM) fibers were tested. The complete spatial characteristics, such as hole diameter and spacing into ASM fibers or sandwiched layer thickness into Bragg fibers, were demonstrated to be attainable anywhere along a bare fiber.

Targeted surveillance to assess the prevalence of BSE in high-risk populations in western France and the associated risk factors

A pilot study was set up for the first time in France in August 2000, to obtain more precise estimates on the BSE epidemic in France. Three categories of cattle at risk of BSE (found dead on-farm, euthanased and emergency slaughtered) were sampled exhaustively from August 7 to December 22, 2000, in the three regions assumed to be the most affected with BSE in France (Basse-Normandie, Bretagne and Pays de la Loire). The samples were checked by using Prionics tests, and positive samples were confirmed by Western blot or immunohistochemistry. The overall prevalence of positive cattle was 0.16 per cent. Multifactorial logistic regression showed that there was a significantly higher prevalence among cattle from the birth cohorts July 1993 to June 1994 and July 1994 to June 1995, than among those born before July 1993, and among the categories 'euthanased' and 'emergency slaughtered' than among the category 'dead on-farm, and a higher prevalence in the regions Pays de la Loire and Bretagne than in Basse-Normandie. No significant differences in the prevalence of BSE were observed between dairy, beef suckler and mixed herds.

Effect of flow on the detoxification function of rat hepatocytes in a bioartificial liver reactor

Ethoxyresorufin-o-deethylation (EROD) can be used as a sensitive measure of hepatic detoxification function. In this study, we employed a fluorescence assay based on EROD to study the effect of varying Peclet number (or flow) on hepatic function in a microchannel flat-plate bioartificial liver (BAL) reactor containing a coculture of hepatocytes and fibroblasts. Static culture and reactor flow experiments established that: 1) a pseudo-steady-state detoxification rate could be attained at each Peclet number, 2) the steady-state detoxification rate increased nonlinearly with Peclet number (ranging from 167 to 2500), 3) the uptake rate of substrate was a linear function of cell surface substrate concentration (<1 microM), and 4) a shear stress of 10 dyne/cm2 did not adversely affect hepatic function for at least 12 h. A convection-diffusion-reaction model supports the conclusion that increased convective mass transfer of substrate to the cell surface is the primary cause of the observed increase in EROD rate with Peclet number. Our results suggest that detoxification rates can be enhanced by an order of magnitude by choosing an appropriate Peclet number. For our bioreactor configuration, this optimum corresponds to a Peclet number range of 1000-2000 at a Damkohler number of 0.55. The usefulness of the mathematical model is discussed in the context of scale-up to a clinical BAL reactor for human application.

Evaluation of minimum inhibitory concentration of quinolones and third generation cephalosporins to Salmonella typhi isolates

A total of 323 Salmonella typhi isolates (261 isolates obtained during 1995-99 from Ludhiana and 62 randomly selected isolates obtained between 1980-99 from Chandigarh) were analyzed for drug resistant pattern. S. typhi isolates prior to 1986 were sensitive to all the antimicrobials tested by disc diffusion method. Most common multidrug resistance pattern noticed was ACCo T i.e. resistance to ampicillin, Chloramphenicol, cotrimoxazole and tetracycline. This study has revealed that withdrawal of chloramphenicol due to high level of resistance during 1990-94, has led to re-emergence of 43-93 percent chloramphenicol sensitive mutants during 1995-99. Two S. typhi isolates in 1995 and one in 1999 from Ludhiana depicted resistance to ciprofloxacin. Susceptibility of S. typhi isolates to third generation cephalosporins ranged between 87 to 100 per cent. There was a gradual increase with time period in mean minimum inhibitory concentration (MIC) of ciprofloxacin as it increased from 0.066 ug/ml for 1980-83 S. typhi isolates to 0.13 ug/ml for the 1996-99 isolates. Similarly, cefotaxime mean MIC for 1980-83 isolate was 0.172 ug/ml which further increased up to 0.32 ug/ml for S. typhi isolates encountered between 1996-99. In contrast, mean MIC value of 0.62 ug/ml of Ceftriaxone remained unchanged irrespective of the year of isolation of S. typhi isolates.

Human immunodeficiency virus type 1 env sequences from Calcutta in eastern India: identification of features that distinguish subtype C sequences in India from other subtype C sequences

India is experiencing a rapid spread of human immunodeficiency virus type 1 (HIV-1), primarily through heterosexual transmission of subtype C viruses. To delineate the molecular features of HIV-1 circulating in India, we sequenced the V3-V4 region of viral env from 21 individuals attending an HIV clinic in Calcutta, the most populous city in the eastern part of the country, and analyzed these and the other Indian sequences in the HIV database. Twenty individuals were infected with viruses having a subtype C env, and one had viruses with a subtype A env. Analyses of 192 subtype C sequences that included one sequence for each subject from this study and from the HIV database revealed that almost all sequences from India, along with a small number from other countries, form a phylogenetically distinct lineage within subtype C, which we designate C(IN). Overall, C(IN) lineage sequences were more closely related to each other (level of diversity, 10.2%) than to subtype C sequences from Botswana, Burundi, South Africa, Tanzania, and Zimbabwe (range, 15.3 to 20.7%). Of the three positions identified as signature amino acid substitution sites for C(IN) sequences (K340E, K350A, and G429E), 56% of the C(IN) sequences contained all three amino acids while 87% of the sequences contained at least two of these substitutions. Among the non-C(IN) sequences, all three amino acids were present in 2%, while 22% contained two or more of these amino acids. These results suggest that much of the current Indian epidemic is descended from a single introduction into the country. Identification of conserved signature amino acid positions could assist epidemiologic tracking and has implications for the development of a vaccine against subtype C HIV-1 in India.

Validation of denaturing high performance liquid chromatography as a rapid detection method for the identification of human INK4A gene mutations

The incidence of melanoma is increasing rapidly in western countries. Genetic predisposition in familial and in some sporadic melanomas has been associated with the presence of INK4A gene mutations. To better define the risk for developing sporadic melanoma based on genetic and environmental interactions, large groups of cases need to be studied. Mutational analysis of genes lacking hot spots for sequence variations is time consuming and expensive. In this study we present the application of denaturing high performance liquid chromatography (DHPLC) for screening of mutations. Exons 1alpha, 2, and 3 were amplified from 129 samples and 13 known mutants, yielding 347 products that were examined at different temperatures. Forty-two of these amplicons showed a distinct non-wild-type profile on the chromatogram. Independent sequencing analysis confirmed 16 different nucleotide variations in Leu32Pro; Ile49Thr; 88 del G; Gln50Arg; Arg24Pro; Met53Ile; Met53Thr; Arg58stop; Pro81Leu; Asp84Ala; Arg80stop; Gly101Trp; Val106Val; Ala148Thr; and in positions (-2) in intron 1 (C --> T); and in the 3' UTR, nucleotide 500 (C --> G). No false negatives or false positives were obtained by DHPLC in samples with mutations or polymorphisms. We conclude that the DHPLC is a fast, sensitive, cost-efficient, and reliable method for the scanning of INK4A somatic or germline mutations and polymorphisms of large number of samples.