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Biomedical subjects

M J Lane

Publications and source records attributed to M J Lane.

At least 37 records · Page 2Linked to original sources

Non-contrast spiral CT for patients with suspected renal colic.

Renal colic, defined as acute flank pain caused by the passage of a ureteral calculus, is a common condition, but the correct diagnosis may not be apparent clinically. For decades, intravenous urography has been the test of choice for evaluating patients with suspected renal colic. Recently, unenhanced (non-contrast) helical CT has been shown to be an accurate and highly effective examination which can be used instead of intravenous urography. In this article, the technique is reviewed in detail, including its advantages and potential pitfalls.

Adult↗

Spontaneous intramural small bowel haemorrhage: importance of non-contrast CT.

The purpose of this study was to evaluate the abdominal CT findings in patients with spontaneous intramural small bowel haemorrhage. We retrospectively reviewed the abdominal CT scans of six patients with known intramural small bowel haemorrhage. All of the patients had an underlying coagulopathy. All six patients underwent CT examinations without oral or intravenous contrast media. All six non-contrast CT scans showed hyperattenuation of the involved bowel segments, with thickened and dilated proximal small bowel. Therefore, patients who are clinically at risk for intramural small bowel haemorrhage should undergo a non-contrast CT scan of the abdomen prior to the routine oral and intravenous contrast-enhanced scan. In most cases the non-contrast scan will provide definitive diagnostic information which may not be evident from the contrast-enhanced scan alone.

Adult↗

Unenhanced helical CT for suspected acute appendicitis.

OBJECTIVE: The purpose of this study was to determine the diagnostic accuracy of unenhanced helical CT scans in patients with a suspected acute appendicitis. SUBJECTS AND METHODS: Over a 20-month period, 109 adult patients with suspected acute appendicitis were referred by the emergency department for an unenhanced helical CT scan. Each scan was obtained in a single breath-hold from the T12 vertebral body to the public symphysis using a 5-mm collimation and a pitch of 1.6. No patients were given oral or IV contrast media. The primary CT criteria for diagnosing acute appendicitis was the identification of an appendix with a transverse diameter larger than 6 mm with associated periappendiceal inflammatory changes. The presence of an appendicolith was considered a secondary finding as was isolated periappendiceal inflammation; however, appendicitis was not diagnosed in such patients unless an enlarged appendix was definitely identified. Final diagnoses were established by surgical or clinical follow-up and were compared with the original CT reports. RESULTS: We found 66 true-negatives, 37 true-positives, four false-negatives, and two false-positives that yielded a sensitivity of 90%, a specificity of 97%, a positive predictive value of 95%, a negative predictive value of 95%, and an accuracy of 94%. An alternative diagnosis was established by an unenhanced helical CT scan in 24 patients (22%), which included cecal diverticulitis (seven patients), urinary tract disease (five patients), adnexal pathology (four patients), sigmoid diverticulitis (two patients), small bowel disease (three patients), right lower quadrant tumor (two patients), and an infected dialysis catheter (one patient). CONCLUSION: Unenhanced thin-section helical CT is an accurate, effective technique for diagnosing acute appendicitis.

Acute Disease↗

Diagnosis of pancreatic injury after blunt abdominal trauma.

Expeditious diagnosis and treatment of pancreatic injury continues to elude the trauma surgeon and radiologist. Missed or underestimated pancreatic injury is responsible for a high level of morbidity and mortality after blunt or penetrating trauma. Unfortunately, inappropriate therapy can lead to devastating consequences such as severe endocrine or exocrine insufficiency. Abdominal CT is currently the imaging method of choice for evaluating patients with blunt trauma. This article reviews the constellation of CT findings that the radiologist must rely on to establish the diagnosis of pancreatic injury.

Abdominal Injuries↗

Optimization of thoracic spiral CT: effects of iodinated contrast medium concentration.

PURPOSE: To determine the effect of varying iodine concentration on arterial enhancement and perivenous artifact during thoracic spiral computed tomographic (CT) scanning. MATERIALS AND METHODS: One hundred thirty-eight outpatients received 15.0 g (n = 76) or 22.5 g (n = 62) of iodine (300 mg/mL iodine) while undergoing thoracic spiral CT. Patients received either undiluted contrast medium, 1:1 normal saline dilution, or 3:1 normal saline dilution. Contrast medium was injected at a flow rate determined to deliver the entire iodine dose within 40 seconds. Attenuation was measured within arteries and veins. Three blinded thoracic radiologists independently graded perivenous artifact and arterial enhancement. RESULTS: Perivenous artifacts were statistically significantly reduced with successive iodine dilution (P < .002). Arterial enhancement was statistically significantly better with 15.0 g of iodine diluted 1:1 when compared with the same iodine dose undiluted or diluted 3:1 (P < .01). Arterial enhancement achieved with 15.0 g of iodine diluted 1:1 was not statistically significantly lower than that achieved with 22.5 g of iodine diluted 1:1 (P > .31); however, venous artifact was greater with 22.5 g of iodine (P < .004). CONCLUSION: Reduced iodine concentration appears to diminish perivenous artifact and to result in improved arterial enhancement during thoracic spiral CT.

Adult↗

Unenhanced helical CT of ureteral stones: incidence of associated urinary tract findings.

OBJECTIVE: The objective of this study was to determine the incidence of urinary tract findings associated with ureteral stones on unenhanced helical CT scans of patients with acute renal colic. MATERIALS AND METHODS: One hundred forty-one consecutive patients with suspected renal colic were referred by the emergency department for a helical CT scan that was obtained without oral or IV contrast. The CT scans of 54 of these patients were interpreted as positive for ureteral calculi, and these CT scans were reviewed retrospectively. The size and location of each ureteral calculus and of any concurrent urinary tract calculi were recorded. The presence or absence of hydronephrosis, hydroureter, perinephric edema or soft-tissue stranding, and periureteral edema was also noted. RESULTS: We reviewed the original 5-mm axial images from the 54 CT scans. Calculi were present in the proximal, mid, and distal ureter in eight, four, and 14 patients respectively, and at the ureterovesicular junction in 28 patients. Only two patients had more than one ureteral calculus, and none had a contralateral ureteral calculus. Concurrent renal parenchymal and/or nonobstructing calculi in the renal pelvis were seen in five patients with proximal, mid, or distal ureteral stones and in 16 patients with ureterovesicular junction stones. Hydronephrosis was found in 37 patients, hydroureter in 36 patients, and perinephric soft-tissue changes in 35 patients. Periureteral edema could not be evaluated in the 28 patients with ureterovesicular junction calculi because of the adjacent bladder, but periureteral edema was clearly seen immediately adjacent to the ureteral stone in 17 of the other 26 patients. Only two of the 54 patients had no evidence of hydronephrosis, hydroureter, or perinephric soft-tissue changes. CONCLUSION: In patients with ureteral calculi imaged with unenhanced CT for acute renal colic, associated findings included hydronephrosis, hydroureter, perinephric soft-tissue changes, and periureteral edema. These common findings provided supportive evidence that an acute obstructive process was present.

Adolescent↗

Trends in mortality and health behaviors: status of white and African-American women.

A substantial proportion of mortality in the United States can be attributed to three major behaviors: using tobacco, maintaining an unhealthy diet, and being physically inactive. Using data from the South Carolina mortality files and Behavioral Risk Factor Surveillance System we were able to document state trends in mortality, cigarette smoking, physical inactivity, and unhealthy dietary practices. We found that, in spite of the declines in heart disease and stroke mortality noted nationally and in the state, the risk factor profiles for most women in South Carolina did not improve. This analysis further suggests that physical inactivity and dietary issues (excess caloric intake, low fruit and vegetable consumption) would be good choices for lifestyle interventions among women in South Carolina, not only because they ultimately affect mortality, but also because they exert interim effects on morbidity, including physical functioning and independence.

Black or African American↗

Predictors of adopting leisure-time physical activity among a biracial community cohort.

Literature on the correlates and predictors of leisure-time physical activity among African-American population is sparse. This cohort study assessed correlates of leisure-time physical activity (specific large muscle activities during the past month at least three times a week) in a biracial population in 1987 and predictors for the adoption of this behavior 4 years later among those initially inactive. Random digit dialing methods were used to identify residents of two South Carolina communities in 1987. In 1991, 3,223 of these residents were resurveyed (62% response rate). In general, the correlates of leisure-time physical activity (education, > or = 12 years; nonsmoking; weight loss behaviors; and physician advice) were similar for each sex and race group. In 1987, the definition of leisure-time physical activity was not met by 831 (54% of 1,542) white women, 374 (76% of 489) African-American women, 586 (59% of 991) white men, and 126 (63% of 201) African-American men. Among those who were inactive in 1987, 22-24% of white adults and African-American men and 14% of African-American women adopted physical activity 4 years later. Twelve years or more of education was a predictor among white women (risk ratio = 1.7, 95% confidence interval 1.2-2.6) and African-American women (risk ratio = 3.1, 95% confidence interval 1.4-6.9), but not among men. Having a physician discuss physical activity was a predictor among white women (risk ratio = 1.9, 95% confidence interval 1.3-2.7), African-American women (risk ratio = 1.7, 95% confidence interval 0.9-3.2), white men (risk ratio = 2.0, 95% confidence interval 1.3-3.1), and African-American men (risk ratio = 2.7, 95% confidence interval 1.0-7.6). These results highlight the strong effect of educational attainment on adoption of healthy behaviors and support the involvement of physicians to promote physical activity among all race and sex groups.

Adult↗

Regional localization of the putative cell surface receptor for HTLV-I to human chromosome 17q23.2-17q25.3.

The gene for the cell surface receptor for HTLV-I, the etiologic agent of adult T-cell leukemia and HTLV-I-associated myelopathy, has been localized to distal human chromosome 17q. A panel of somatic cell hybrids containing fragments of human 17q as the only human genetic component was mapped with a set of 10 chromosome 17 probes and utilized to regionally localize the gene. When compared to the murine fibroblast fusion partner, L-M(TK-), and a hybrid cell line containing human chromosome 20, human 17q-containing hybrid cells bound high levels of both HTLV-I virions and the monoclonal antibody, Mab 34-23, which may be directed against the putative HTLV-I receptor. Additional experiments revealed that the human 17q-containing hybrids could also be more efficiently infected by cell-free HTLV-I virions than could the control cell lines. Western blot analyses of cell lysates showed that recombinant HTLV-I envelope gp46 protein and Mab 34-23 both bound to proteins of approximate MW 30 and 31 kDa which were found only in the hybrid cell lines which contained human chromosome 17q. The data suggest that the gene for the HTLV-I receptor is located on the distal region of human chromosome 17q demarcated by the tk-1 locus (17q23.2-17q25.3).

Antigens, Surface↗

Increased detection of hepatitis C virus infection in commercial plasma donors by a third-generation screening assay.

BACKGROUND: Routine screening of blood donations with second-generation hepatitis hepatitis C virus (HCV) assays has substantially reduced the occurrence of posttransfusion hepatitis. However, following the development of third-generation assays, several studies indicated that these assays may identify HCV-infected individuals who are not identified by second-generation assays. STUDY DESIGN AND METHODS: The sensitivity of a third-generation HCV enzyme-linked immunosorbent assay (ELISA-3) was compared with a second-generation ELISA (ELISA-2) in a side-by-side study of 9936 commercial blood donors. ELISA-reactive specimens were subjected to supplemental analysis by third-generation recombinant immunoblot assay and polymerase chain reaction. RESULTS: ELISA-3 demonstrated greater sensitivity than ELISA-2, detecting 1 additional recombinant immunoblot assay-positive specimen per 2000 tested. ELISA-3 also detected 1 additional HCV-infectious polymerase chain reaction-positive unit among approximately 10,000 units screened. CONCLUSION: The incremental sensitivity achieved with ELISA-3 can be expected to eliminate approximately 20 infectious donations per week among those made by commercial donors in the United States. In accordance with previous studies, most of the improved sensitivity of ELISA-3 derives from its increased detection of anti-c33c (NS3), rather than from the inclusion of HCV antigen NS5.

Blood Donors↗

The association between alcohol use and health behaviors related to the risk of cardiovascular disease: the South Carolina Cardiovascular Disease Prevention Project.

OBJECTIVE: This study examines the relationship between alcohol use and health behaviors related to the risk of cardiovascular disease (CVD). In particular, we examined the relationship between alcohol use and leisure time physical activity, participation in community physical activity programs and behaviors used for weight loss. Numerous studies have found a "protective" effect of moderate alcohol consumption on the risk of CVD. However, most of these studies have not adequately controlled for potential confounding by health behaviors associated with alcohol use. METHOD: We used descriptive and logistic regression analyses to examine cross-sectional survey data from 2,072 participants in the South Carolina Cardiovascular Disease Prevention Project. RESULTS: After controlling for age, race, education and preexisting CVD, moderate and heavy drinkers who do not smoke were more likely than nondrinkers to report engaging in regular leisure time physical activity. The relationship between other health behaviors and alcohol consumption was less clear. Among men, moderate and heavy drinkers were no more likely than nondrinkers to participate in community physical activity programs; among women, moderate and heavy drinkers were more likely than nondrinkers to report this activity. Moderate drinkers were more likely than nondrinkers to report that they were attempting to lose weight, however this difference was not statistically significant. CONCLUSIONS: These data suggest that at least some of the apparent protective effect of moderate alcohol consumption found in other studies may be due to differences between nondrinkers and drinkers with respect to physical activity and other health practices.

Adolescent↗

CT diagnosis of blunt pancreatic trauma: importance of detecting fluid between the pancreas and the splenic vein.

OBJECTIVE: The purpose of this study was to determine the value of detecting fluid between the splenic vein and the pancreas on CT scans in the diagnosis of pancreatic injury after blunt abdominal trauma. MATERIALS AND METHODS: We retrospectively reviewed the abdominal CT scans of 10 patients with surgical- or autopsy-proved pancreatic injury after blunt abdominal trauma. The finding of fluid interdigitating between the pancreas and the splenic vein was then studied along with the reported CT features of pancreatic injury. These included intraperitoneal fluid, fluid in the lesser sac, extraperitoneal fluid, pancreatic edema or hematoma, and thickening of the anterior renal fascia. RESULTS: The CT scans of all 10 patients reviewed showed abnormalities suggesting pancreatic injury. Only 40% of patients showed all of the findings reported in the literature. Fluid interdigitating between the splenic vein and the pancreatic parenchyma was seen on CT scans in 90%. CONCLUSION: Our experience suggests that fluid between the splenic vein and the pancreas is a helpful CT finding for the diagnosis of pancreatic injury after blunt abdominal trauma. This finding was easy to recognize and in the proper clinical setting directs attention to additional subtle findings of pancreatic injury.

Adult↗

Identification of a putative cellular receptor for HTLV-I by a monoclonal antibody, Mab 34-23.

The ability of HTLV-I to infect cells is presumed to be dependent, in some part, on the attachment of the virus to a target cell via a specific cell surface receptor which is, as yet, unknown. Here we present evidence that a monoclonal antibody, Mab 34-23, inhibits the binding of HTLV-I to IL-2 and phytohemagglutinin-activated peripheral blood mononuclear cells and also inhibits virus entry into these cells. Analysis of a variety of target cells, including a human:mouse somatic hybrid which contains only human chromosome 17q, indicates that the binding of Mab 34-23 correlates with HTLV-I adsorption and entry. SDS-PAGE and Western blot analysis show that Mab 34-23 binds to four major proteins of MW 31, 45, 55, and 70 kDa and this binding can be inhibited by HTLV-I and not HIV proteins. HTLV-I virions bind to proteins of similar molecular weight and virus-binding to these proteins can be inhibited by preincubation with Mab 34-23. These data suggest that Mab 34-23 may identify a specific cell surface receptor(s) for HTLV-I.

Antibodies, Monoclonal↗

Gilvocarcin V exhibits both equilibrium DNA binding and UV light induced DNA adduct formation which is sequence context dependent.

The relative degree of both equilibrium binding and of ultraviolet light induced adduct formation for the antitumor antibiotic gilvocarin V with two hexaecamer DNA sequence isomers, d[ATATATAGCTATATAT]2 and d[AAAAAAAGCTTTTTTT]2, was assessed. The experiments reveal that gilvocarin V binds, under equilibrium conditions, and reacts, in the presence of exogenously applied UV light, more efficiently with the alternating purine:pyrimidine sequence hexadecamer than the homopurine:homopyrimidine duplex at identical gilvocarcin V to DNA duplex ratios. DNAse I digests of adduct containing duplexes derived from the d[AAAAAAAGCTTTTTTT]2 duplex, identified and isolated using gel shift assays employing denaturing polyacrylamide gels, confirm that gilvocarcin V adducts can be formed with thymine residues but suggest that adduct formation with either adenine or guanine residues is also possible.

Aminoglycosides↗

Variation in genomic Alu repeat density as a basis for rapid construction of low resolution physical maps of human chromosomes.

Human DNA restriction fragments containing high numbers of Alu repeat sequences can be preferentially detected in the presence of other human DNA restriction fragments in DNA from human: rodent somatic cell hybrids when the DNA is fragmented with enzymes that cleave mammalian DNA infrequently. This ability to lower the observed human DNA complexity allowed us to develop an approach to order rapidly somatic hybrid cell lines retaining overlapping human genomic domains. The ordering process also generates a relative physical map of the human fragments detected with Alu probe DNA. This process can generate physical mapping information for human genomic domains as large as an entire chromosome (100,000 kb). The strategy is demonstrated by ordering Alu-detected NotI fragments in a panel of mouse: human hybrid cells that span the entire long arm of human chromosome 17.

Chromosome Mapping↗