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Biomedical subjects

C G Torres

Publications and source records attributed to C G Torres.

11 recordsLinked to original sources
PubMed2000

MRI with mangafodipir trisodium in the detection and staging of pancreatic cancer.

The purpose of this study was to compare prospectively computed tomography (CT) and magnetic resonance (MR) imaging before and after mangafodipir trisodium infusion for the detection and staging of focal pancreatic lesions. From November 1996 to October 1997, 43 consecutive patients suspected to have a focal pancreatic lesion were included in a phase III study. Triphasic helical CT was performed, as well as MRI at 1.5 T, as follows: axial T1-weighted (T1w) turbo spin echo (TSE), spectral presaturation with inversion recovery (SPIR) T1w TSE, T1w turbo field echo (TFE), and SPIR T2w TSE before and after mangafodipir trisodium (0.01 mmol/ml, 0.5 ml/kg) infusion. Imaging results were correlated with surgery, laparoscopy, laparoscopic ultrasound, and biopsy. Objective measurements were performed by measuring signal intensities (SIs) of lesion and parenchyma and calculating contrast indexes (CIs) and contrast-to-noise-ratios (CNRs) to assess the delineation of the tumor. SIs were correlated with four phantom standards with a known SI. Thirty-eight pancreatic adenocarcinomas were present, as well as one cystadenoma, two papillomas, and two cases of focal pancreatitis. SI measurements revealed significant increases in CIs for the lesion compared with the parenchyma in T1w TSE (69.7 vs 152.7; P = 0. 0003) and T1w TFE (107.8 vs 194.2; P = 0.0002). These series also revealed significant increases in CNRs (for T1w TSE: 9.7 vs 13.0; P = 0.0407 and for T1w TFE: 14.5 vs 26.1; P = 0.0001). In the other series, there was no significant increase. CT detected 38 lesions, MRI without mangafodipir trisodium detected 39 lesions, and MRI with mangafodipir trisodium detected 40 lesions, giving detection accuracy rates of 88%, 91%, and 93%, respectively. Staging accuracy rates for vascular ingrowth were 81%, 75%, and 81%, respectively. Overall staging accuracy rates were 57%, 54%, and 54%, respectively, mostly due to undetected small metastases in the peritoneum, omentum, or liver (< 1 cm). This study indicates that a) MRI after mangafodipir trisodium gives a better delineation of the tumor in T1w series, but b) does not significantly improve the detection rate and staging accuracy of focal pancreatic lesions over MRI without this contrast medium.

Adult↗
PubMed1997

MnDPDP for MR imaging of the liver. Results from the European phase III studies.

PURPOSE: To evaluate the diagnostic efficacy and safety of MnDPDP (Teslascan) in enhanced MR imaging. MATERIAL AND METHODS: In 2 multiple independent trials in Europe 624 patients were given MnDPDP intravenously at 5 mumol/kg b.w. Patients underwent an unenhanced MR examination comprising T1-weighted spin-echo and breath-hold gradient-echo sequences and a T2-weighted spin-echo sequence. The T1 sequences were repeated after the administration of MnDPDP. In a subgroup of 137 patients the results of the enhanced MR images were compared with the results of contrast-enhanced CT (CECT) images. RESULTS: For both types of T1-weighted sequences and when evaluating the maximum numbers of lesions seen in all imaging sequences, the total numbers of lesions seen were significantly higher in the MnDPDP-enhanced images than in the unenhanced images (p = 0.0005 and p = 0.0001, respectively). The investigators considered the enhanced images to contain "other additional information not found in the unenhanced images" in 279 (45%) of the 621 patients examined. The MnDPDP-enhanced images were also superior to the CECT images in the detection of lesions (p = 0.02). Adverse events were reported by 46 patients (7%) and infusion-associated discomfort by 26 (4%). Heart rates and systolic and diastolic blood pressures showed no clinically significant changes from baseline as a result of the administration of the contrast medium. CONCLUSION: MnDPDP was shown to be effective and safe in enhanced MR imaging of the liver.

Adult↗
PubMed1997

MnDPDP for MR imaging of the liver. Results of an independent image evaluation of the European phase III studies.

PURPOSE: To evaluate the diagnostic efficacy of mangafodipir trisodium (MnDPDP, Teslascan) as a new contrast agent for MR imaging of the liver based on an independent evaluation of the MR images from the European phase III studies. MATERIAL AND METHODS: MR imaging of the liver was done at 0.5-2.0 T in 17 European centres and included T1-weighted spin-echo and gradient-echo sequences before and after administration of MnDPDP to patients at a dose of 5 mumol/kg b.w. T2-weighted images were also obtained in all cases before the i.v. injection of the agent. Images of a total of 592 patients were evaluated by 4 independent experienced radiologists who were not involved in the on-site clinical trials. RESULTS: Statistically significantly more lesions were detected (p = 0.0014) in MnDPDP-enhanced T1-weighted MR images than in unenhanced images. T1-weighted gradient-echo sequences were found to be superior to T1-weighted spin-echo sequences after injection of MnDPDP. The post-contrast images were found to be statistically significantly superior to the pre-contrast images in confidence in the presence of a lesion (p < or = 0.0001), quality of lesion delineation (p < or = 0.0001), lesion conspicuity (p < or = 0.0001) and in the confidence in the diagnosis of a lesion (p = 0.001). CONCLUSION: This independent evaluation of the European phase III trials confirmed the superiority of MnDPDP-enhanced MR images over unenhanced images for lesion detection and characterization.

Adult↗
PubMed1994

Neuropsychological deficit among elderly workers in aluminum production.

A cross-sectional study was conducted at a Norwegian primary aluminum plant. All workers aged 61-66 years were offered early retirement benefits. Among the workers, 47 met the study criteria and 38 (81%), comprising 14 potroom workers, 8 foundry workers, and 16 controls, volunteered to participate. They were tested with a neuropsychological test battery. Workers in potrooms with Søderberg electrolytic cells were found to show signs of impairment of the nervous system. A test for tremor discriminated significantly between the potroom group and the controls. There was a suggestion of increased risk of impaired visuospatial organization and a tendency to a decline in psychomotor tempo in the potroom workers. We suggest that the above findings may be related to long-term occupational exposure in the potroom, and further to chronic low-dose exposure to aluminum.

Aged↗
PubMed1993

Epidemiologic patterns of nosocomial infections in 10 Oklahoma hospitals.

The epidemiology of nosocomial infections was studied for 5 years in 10 Oklahoma hospitals. These were categorized into small and large hospitals. The seven small hospitals averaged 47 beds and the three large hospitals averaged 266 beds. Overall, most of the infected patients were < 5 years of > 60 years of age. Females accounted for the majority of the infections. In general, the three most common sites of infection were the urinary tract, surgical wounds, and the lower respiratory tract. Escherichia coli was the single most frequently identified agent followed by Staphylococcus aureus and Staphylococcus epidermidis. The most frequently reported risk factors among patients acquiring a nosocomial infection were the use of prior antibiotics, indwelling urinary catheters, and intravenous catheters or cut-down. The specific problems associated with nosocomial infections, such as sites of infection, risks of infection, and the types of organisms isolated, essentially had not changed much since the 1960s, the 1970s, and for most of the 1980s.

Adolescent↗
PubMed1992

A nationwide cross-sectional study of retinopathy and microalbuminuria in young Norwegian type 1 (insulin-dependent) diabetic patients.

A nationwide cohort of Type 1 (insulin-dependent) diabetic patients was studied to determine the prevalence of retinopathy and microalbuminuria and to evaluate the association to various risk factors. Of 600 subjects with mean age of 19.8 years (range 8.0-30.3) and a mean duration of diabetes of 10.5 years (range 6.2-17.3), 371 (60%) volunteered for a clinical examination which included fundus photography, timed overnight urine samples for albumin excretion rate, measurement of arterial blood pressure and determination of HbA1c. Retinopathy was found in 122 of 371 patients (32.8%), in 3 of 41 (7.3%) patients aged less than 13 years. The youngest subject with retinopathy was 9.6 years old. Microalbuminuria was found in 44 of 351 patients (12.5%), in 1 of 41 (2.4%) patients aged less than 13 years. The youngest subject with microalbuminuria was 11.5 years old. Mean HbA1c was 8.6% (normal range 4.5-601%). Patients with retinopathy had significantly higher mean age (p = 0.0001), longer mean duration of diabetes (p = 0.0001), higher mean HbA1c (p = 0.009), and higher mean arterial blood pressure (p = 0.0001) compared to patients without retinopathy. In microalbuminuric patients HbA1c (p = 0.001) and mean arterial blood pressure (p = 0.01) were significantly higher compared to non-microalbuminuric patients, but there was no difference in age or diabetes duration. In a multiple logistic regression model, age, HbA1c, duration of diabetes and mean arterial blood pressure were found to be significantly associated with retinopathy, while HbA1c, mean arterial blood pressure and onset before 13.0 years of age were found to be associated with microalbuminuria.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

The effect of sperm number on fertility in blue fox vixens (Alopex lagopus ) artificially inseminated with frozen silver fox (Vulpes vulpes ) semen.

During the breeding seasons of 1989 and 1990, a total of 617 blue fox vixens aged 1 to 6 years (mean +/- SEM, 2.6 +/- 0.1) were inseminated with frozen silver fox semen with either 150 million (n = 213, 1989 + 1990), 100 million (n=172, 1990), 75 million (n = 119, 1989) or 37.5 million (n = 113, 1989) spermatozoa per insemination. Two intrauterine inseminations, each with an insemination volume of 1.0 ml, were performed at 24-hour intervals on the first and second days after maximum vaginal electrical resistance was measured. Conception rates were 87% (186 of 213) with 150 million spermatozoa per insemination, 85% (146 of 172) with 100 million, 77% (91 of 119) with 75 million and 68% (77 of 113) with 37.5 million. The mean numbers of cubs per litter +/- SEM for the four groups were 7.6 +/- 0.2 (168 registered litters), 7.5 +/- 0.3 (115 litters), 6.4 +/- 0.4 (86 litters) and 6.4 +/- 0.4 (75 litters). A negative effect on both the conception rate and mean litter size at whelping was observed with decreasing sperm numbers (conception rate percentage: p = 0.0001, Chi-square, litter size: p = 0.02, Kruskal-Wallis Test). Only the two larger numbers of spermatozoa gave litter sizes comparable to those obtained by artificial insemination (AI) with fresh semen.

Journal Article↗
PubMed1992

The optimum time for single artificial insemination of blue fox vixens (Alopex lagopus) with frozen-thawed semen from silver foxes (Vulpes vulpes).

During the breeding season of 1991 a total of 608 blue fox vixens aged 1 to 6 years (2.3 +/- 0.1 years, mean +/- SEM) from 2 farms were artificially inseminated intrauterine once with frozen-thawed silver fox semen (1 ml dose containing a total of 150 million spermatozoa). The vixens were allocated to 3 different groups according to the time of insemination. Vixens in Group 1 (n = 203), Group 2 (n = 198), and Group 3 (n = 207) were inseminated on the first, second or third day after the peak value of vaginal electrical resistance, respectively. An overall conception rate of 75% (456 of 608) and 6.0 +/- 0.1 (mean +/- SEM) cubs per litter was obtained. Conception rates and mean litter sizes were significantly different between groups of vixens with respect to day of insemination (P = 0.02, Chisquare, Kruskall-Wallis Test). Vixens inseminated on the second day (Group 2) had the highest conception rate (81%) and the largest mean litter size (7.0 +/- 0.2 cubs) of the three groups, while those inseminated on the third day (Group 3) had the lowest conception rate and mean litter size (70%, 5.4 +/- 0.3 cubs).

Journal Article↗
PubMed1991

Security measures for AIDS and HIV.

This study describes the measures being taken by AIDS surveillance offices across the country to ensure the security of information regarding patients with AIDS and HIV infection. Security measures were evaluated according to the cumulative number of AIDS cases reported, whether partner notification services were provided, and whether HIV seropositive reporting by name was also required. This study showed that public health departments have taken extra steps to ensure the security of AIDS and HIV data.

Acquired Immunodeficiency Syndrome↗
PubMed1983

A descriptive study of Kaposi's sarcoma in south Florida.

A larger-than-expected incidence of Kaposi's sarcoma in women is observed in south Florida. The possibility of a shift in cancer experience to groups previously considered at low risk (eg, women and blacks) or tumors (eg, Kaposi's sarcoma) is suggested.

Adult↗