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Biomedical subjects

S McCarthy

Publications and source records attributed to S McCarthy.

At least 55 records · Page 3Linked to original sources
PubMed1996

Diffuse adenomyosis: comparison of endovaginal US and MR imaging with histopathologic correlation.

PURPOSE: To compare the accuracy of endovaginal ultrasound (US) and magnetic resonance (MR) imaging in the diagnosis of adenomyosis. MATERIALS AND METHODS: The authors prospectively studied 119 consecutive patients undergoing hysterectomy. The endovaginal US scans and MR images were interpreted independently in a double-blind fashion. Imaging findings were compared with those at histopathologic examination. RESULTS: At histopathologic examination, adenomyosis was found in 28 of the 119 patients (24%). Sensitivity and specificity was 89% for endovaginal US and 89% for MR imaging. The positive predictive value was 71% for US and 65% for MR imaging. The negative predictive value was 96% for US and 95% for MR imaging. There was no statistically significant difference between the sensitivities (P = .65) and specificities (P = .75) of endovaginal US and MR imaging. The mean junctional zone (JZ) thickness on MR images in patients with and without proved adenomyosis was 15.0 mm +/- 4.9 and 7.7 mm +/- 3.3, respectively (P < .0001). When receiver operating characteristic curves were applied retrospectively, the optimal JZ value for the diagnosis of adenomyosis with MR imaging was > or = 12 mm. CONCLUSION: Endovaginal US was as accurate as MR imaging in the diagnosis of uterine adenomyosis. Use of a JZ thickness of > or= 12 mm should further optimize the diagnostic accuracy of MR imaging.

Double-Blind Method↗
PubMed1996

Hyperleptinemia: an early sign of juvenile obesity. Relations to body fat depots and insulin concentrations.

Leptin, the OB gene product, is an adipocyte-derived circulating protein. In several rodent models of obesity, such as the db/db mice, fa/fa rats, and ventromedial hypothalamus-lesioned mice, as well as adult obese subjects, leptin mRNA expression and the circulating levels are elevated, suggesting resistance to its action. However, it is unknown whether the rise in leptin concentration occurs early in the natural evolution of human obesity or is a chronic adaptation to the obese state. Moreover, whether the distribution of body fat (i.e., visceral vs. subcutaneous abdominal fat) influences circulating leptin levels has not been assessed. We have determined in a group of obese and nonobese children and young adults whether leptin levels 1) are increased early in the development of obesity, 2) are related to a specific fat depot measured by magnetic resonance imaging, 3) vary during hyperinsulinemic, euglycemic, and hyperglycemic clamp studies, and 4) are different in males vs. females. In the basal state, leptin levels were elevated in obese children. Children and adults demonstrated a strong positive correlation between leptin concentrations and the subcutaneous fat depot (r = 0.84, P < 0.001). Surprisingly, a weaker correlation was found with visceral fat mass (r = 0.59, P = 0.001). Leptin levels remained unchanged under both euglycemic and hyperglycemic hyperinsulinemic conditions in both obese and nonobese subjects. A pronounced effect of gender on leptin levels was also observed. We conclude that, early in the development of juvenile obesity, leptin concentrations are elevated and are more closely linked to subcutaneous than visceral fat mass. Acute increases in insulin concentrations do not affect circulating leptin levels.

Adipose Tissue↗
PubMed1996

Diagnosis of acute flank pain: value of unenhanced helical CT.

OBJECTIVES: The purpose of our study was to determine the value of unenhanced CT in the diagnosis of acute flank pain. We determined the accuracy of unenhanced Ct for stone detection as well as the detection of abnormalities unrelated to stone disease. MATERIALS AND METHODS: During an 18-month interval, 292 patients with acute flank pain were imaged with unenhanced CT. Confirmation of the CT diagnosis was obtained for 210 patients: One hundred patients were proved to have ureteral stones based on other imaging studies (58 patients), lithotripsy (seven patients), ureteroscopic stone extraction (five patients), and stone recovery (30 patients). One hundred ten patients were proved not to have ureteral stones based on other imaging studies (24 patients), failure to recover a stone (56 patients), or a confirmed diagnosis unrelated to stone disease (30 patients). This latter group of 30 patients included diagnoses of adnexal masses (eight patients), appendicitis (five patients), diverticulitis (four patients), and common bile duct stones (three patients), as well as other diagnoses. RESULTS: Unenhanced CT findings were falsely negative for stone disease in three patients and falsely positive for stone disease in four patients. These data yield a sensitivity of 97%, a specificity of 96%, and an accuracy of 97% for diagnosing ureteral stone disease. Of 31 patients with a CT abnormality unrelated to stone disease, there was one false-negative diagnosis of acute appendicitis. CONCLUSION: Unenhanced CT is a valuable technique for examining patients with acute flank pain in whom a clinical diagnosis is uncertain. It can accurately determine the presence or absence of ureteral stones as well as extraurinary causes of acute flank pain. In most cases, other imaging studies are not required.

Acute Disease↗
PubMed1996

Acute ureteral obstruction: value of secondary signs of helical unenhanced CT.

OBJECTIVE: The purpose of our study was to determine the value of secondary signs of ureteral obstruction on helical unenhanced CT. MATERIALS AND METHODS: Over a 19-month interval, 312 patients with acute flank pain were imaged with helical unenhanced CT. Ureteral stone disease was confirmed to be present in 109 patients and confirmed to be absent in 111 patients Ninety-two remaining patients had no confirmatory imaging studies or surgery and were unable to be contacted for follow-up. For each of the 220 patients with a confirmed diagnosis, we determined the presence or absence of ureteral or collecting system dilatation, perinephric stranding, symmetry of renal size, and renal stones. In all patients with a ureteral stone, we noted the presence or absence of a circumferential rim of soft-tissue attenuation ("tissue-rim" sign) surrounding each stone and each phlebolith. RESULTS: The sensitivity of each secondary sign was ureteral dilatation, 90%; perinephric stranding, 82%; collecting system dilatation, 83%; and renal enlargement, 71%. The specificity of each secondary sign was ureteral dilatation, 93%; perinephric stranding, 93%; collecting system dilatation, 94%; and renal enlargement, 89%. Ureteral dilatation and perinephric stranding were both present or both absent in 181 of the 220 patients with a confirmed diagnosis. In this subgroup, this combination of signs had a positive predictive value of 99% and a negative predictive value of 95%. The odds ratio for the frequency of the tissue-rim sign with stones versus tissue-rim with phleboliths was 31:1. CONCLUSION: When using unenhanced CT to help diagnose acute flank pain, if one does not see a ureteral stone or does see an indeterminate but suspicious calcification, then secondary signs of obstruction are important for diagnosis. The results of this study form the basis of an imaging algorithm that can be used when interpreting unenhanced CT images of patients with acute flank pain.

Acute Disease↗
PubMed1995

'Doing the right thing': the symbolic meanings and experiences of having an HIV antibody test.

Very few studies have been undertaken to explore in depth the reasons why individuals seek HIV antibody testing. This paper discusses the socio-cultural meanings surrounding the HIV antibody test, using the findings from a qualitative study directed at understanding why 'low risk' individuals make the decision to have an HIV test, their experiences of testing and their use of the result, especially in negotiating sexual relationships. It is concluded that the less obvious reasons for taking the test include pressure from parents or lovers, as a symbolic closure or commencement of a sexual relationship, the discourse of mutuality, the privileging of 'knowledge' and notions of responsibility and purity. Implications for AIDS education programs and policy are addressed.

AIDS Serodiagnosis↗
PubMed1995

Substance use among schoolchildren in the north of England.

A confidential and anonymous survey of 3623 adolescents was carried out in eight schools (six state comprehensive and two independent) in Newcastle upon Tyne. The survey enquired about cigarette use, alcohol consumption and illicit drug use together with key demographic variables. The results showed that 21% were currently smoking and 11% on a frequent basis. Regular smoking was more prevalent among girls. There was substantial use of alcohol, with 75% having used, and 20% drinking on a regular basis. This high level of alcohol consumption may be characteristic of northern Britain. The relatively low reported use of cannabis and relatively high reported use of naturally occurring hallucinogens may constitute a further regional variation. A minority of the sample (1.5%) were using illicit substances on a regular basis. Findings are discussed in terms of previous literature.

Adolescent↗
PubMed1995

Central adiposity and its metabolic correlates in obese adolescent girls.

To establish whether alterations in insulin action and secretion and their relationship to body fat distribution occur early in the course of developing obesity, we studied 14 obese adolescent girls [13.2 +/- 0.7 yr, body mass index (BMI) 32 +/- 1.4], 16 nonobese young women (24.0 +/- 0.6 yr, BMI 21.0 +/- 0.9). Insulin action was assessed by a sequential two-step (8 and 40 mU,m-2.min-1) euglycemic insulin clamp in combination with [1-13C]glucose and indirect calorimetry. Insulin secretion was determined by the hyperglycemic clamp technique (6.9 mmol/l). Magnetic resonance imaging was used to quantify visceral and subcutaneous abdominal fat depots. In obese girls, an impairment in glucose disposal was present with both insulin doses; at the higher dose, rates of glucose uptake were reduced by 30% in nonobese girls (240 +/- 30 vs. 340 +/- 19 mg.m-2.min-1, P < 0.05) and by an additional 29% (170 +/- 17 mg.m-2.min-1, P < 0.05) in obese girls. Insulin infusion failed to stimulate glucose oxidation and to suppress lipid oxidation only in obese girls. Suppression of free fatty acid levels, but not hepatic glucose production, was decreased in obese girls compared with controls. Fasting and glucose-stimulated insulin responses were greater in obese than in nonobese adolescents, who, in turn, had greater responses than lean women. In obese girls, visceral fat, but neither waist-to-hip circumference ratio nor subcutaneous fat, was highly correlated with basal insulin secretion (r = 0.89, P < 0.001), stimulated insulin secretion (r = 0.61, P < 0.05), and insulin resistance (r = -0.87, P < 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue↗
PubMed1995

Elevated levels of authentic plasma hydroperoxides in NIDDM.

Using a precise technique for measuring authentic plasma lipid hydroperoxides (ROOHs), we show that individuals with non-insulin-dependent diabetes mellitus (NIDDM) have higher levels of ROOH than do control subjects. ROOHs were measured by the ferrous oxidation with xylenol orange assay coupled with the selective ROOH reductant triphenylphosphine. Formation of the ferric xylenol orange complex was determined at 560 nm and calibrated against H2O2. For 22 individuals with NIDDM, a concentration of 9.04 +/- 4.3 mumol/l (mean +/- SD) ROOH was recorded. This concentration was higher (P < 0.0005 by separate-variance t test) than that of plasma ROOHs from control subjects (3.76 +/- 2.48 mumol/l). There was no difference between concentrations of plasma malondialdehyde measured as thiobarbituric acid-reactive material (TBARM) in NIDDM or control subjects (1.00 +/- 0.70 vs. 1.21 +/- 0.62 mumol/l, respectively; P > 0.1). A trend to lower vitamin E levels in the NIDDM group (9.03 +/- 3.31 vs. 10.31 +/- 5.02 micrograms/ml in control subjects) failed to achieve significance at the 95% confidence level. Plasma ROOHs in the diabetic group did not correlate with total plasma cholesterol, triglyceride, fasting glucose, HbA1, vitamin E, or TBARM levels. These data indicate that measurement of authentic ROOHs shows NIDDM to be associated with oxidative stress, which may be unrelated to abnormalities in lipid metabolism and glycemic control.

Adult↗
PubMed1994

Detection of aortic tear in the acute trauma patient using MRI.

Traumatic aortic tears are life threatening and, therefore, need to be evaluated urgently. Typically, a thoracic aortogram is conducted; however, aortography occasionally demonstrates nonspecific abnormalities. These equivocal examinations can lead to unnecessary thoracotomies, or repeated angiography and catastrophic delays in aortic repair. We report a case in which magnetic resonance (MR) imaging was very useful in the diagnosis of aortic tear.

Acute Disease↗
PubMed1994

Pelvic varices as a cause for pelvic pain: MRI appearance.

Pelvic venous congestion, as a cause of pelvic pain, is often overlooked. MR offers a noninvasive means of diagnosing this entity. Its appearance, as discussed, is important to recognize in patients who are referred for MR evaluation.

Adult↗
PubMed1994

Magnetic resonance imaging evaluation of adnexal masses.

Anatomically, the adnexa encompasses the region within the pelvis that includes the ovary, fallopian tube, round ligament, and structures arising from associated embryologic rests. The scope and spectrum of gynecologic pathology seen in this area is enormously diverse, and specific diagnoses are often elusive to conventionally-used imaging techniques such as ultrasound and CT. MRI has become an important tool in the evaluation of the adnexal mass because of its multiplanar capability and undersurpassed soft tissue contrast. It is particularly effective in defining the origin of a pelvic mass. The recent development of fast spin-echo sequences along with new phased array coils have enabled higher resolution imaging in shortened imaging times. The result is improved characterization of adnexal masses, which often leads to specific diagnoses.

Adnexal Diseases↗
PubMed1994

Pseudoaneurysm of the brachial artery: a rare complication of blood donation.

BACKGROUND: Serious complications of blood donation are rare. Reported here is a significant vascular event that resulted from whole-blood phlebotomy and required surgical repair. CASE REPORT: A 49-year-old woman donated whole blood without incident in November 1992, but reported ecchymosis and tenderness in the antecubital area of the right arm immediately following the procedure (her medical history was unremarkable). Over the next several days, the ecchymosis extended to the axilla and she complained of numbness in all her fingers, particularly the thumb and adjacent two fingers of the involved side. Coincident to these findings, an egg-sized lump developed under the skin at the phlebotomy site. Her symptoms and the mass persisted for several weeks. Examination and ultrasound performed in January 1993 demonstrated a pulsatile mass over the brachial artery. The donor underwent an exploratory surgical procedure that revealed a 3.3 x 2.5 x 2.0-cm pseudoaneurysm of the brachial artery. Unlike a true aneurysm, this lesion was composed only of a blood clot that was compressing the outer wall of the artery. A pinpoint-sized hole was seen in the artery when the lesion was excised. The phlebotomy is believed to have caused blood to leak out of the artery, creating the lesion and exerting pressure on the median nerve. CONCLUSION: Pseudoaneurysm of the femoral artery is a well-documented complication of cardiac catheterization and other invasive arterial procedures, but this is the first known reported case following blood donation. Blood collectors should be made aware of this potentially serious complication of blood donation.

Aneurysm↗
PubMed1994

Phase I AIDS Clinical Trials Group (075) study of adriamycin, bleomycin and vincristine chemotherapy with zidovudine in the treatment of AIDS-related Kaposi's sarcoma.

OBJECTIVE: To determine the toxicity and maximum tolerated dose of doxorubicin (adriamycin) in combination with fixed doses of bleomycin, vincristine (ABV) and zidovudine in patients with advanced AIDS-related Kaposi's sarcoma. PATIENTS AND METHODS: Twenty-six HIV-seropositive men with Kaposi's sarcoma were treated daily with 100 mg zidovudine orally every 4 h, along with combination chemotherapy using bleomycin 10 U/m2 and vincristine 1.4 mg/m2 (maximum, 2 mg) given intravenously in 2-week cycles. In addition, three successive cohorts of eight patients received escalating doses of doxorubicin each beginning with no doxorubicin (level I), doses of 10 mg/m2 (level II), and 15 mg/m2 (level III). RESULTS: The major dose-limiting toxicity experienced with the combination therapy was severe neutropenia in eight patients, four of whom received level III doxorubicin (15 mg/m2). Therefore, 10 mg/m2 of doxorubicin in combination with zidovudine and BV chemotherapy was defined as the maximum tolerated dose. Other dose-limiting toxicities included neuropathy (n = 2), cutaneous toxicity associated with bleomycin (n = 1), and diarrhea (n = 1). Seventeen patients (71%; 95% confidence interval, 46-85) experienced either partial (n = 13) or clinical complete remission (n = 4) to therapy after a median of five cycles (range, 2-9). CONCLUSION: The maximum tolerated dose of doxorubicin is 10 mg/m2 when given in combination with zidovudine and BV chemotherapy. Response rates observed with the combined antiretroviral and chemotherapy regimen are similar to those previously reported with ABV chemotherapy alone.

Acquired Immunodeficiency Syndrome↗
PubMed1994

Platelet function in patients with hypercholesterolaemia.

Platelets and plasma lipoproteins, particularly low density lipoprotein, have important roles in atherogenesis. Evidence from several sources suggests that important interactions occur between these individual components of the atherogeneic process. Here we review work from our own laboratory on platelet function in normal individuals and patients heterozygous for familial hypercholesterolaemia (FH). Data is presented on the role of platelet noradrenaline and also on altered cellular signalling in platelets from FH individuals who have plasma low density lipoprotein concentrations which are approximately double those seen in normal subjects.

Blood Platelets↗
PubMed1994

Female pelvis: impact of MR imaging on treatment decisions and net cost analysis.

PURPOSE: To determine the impact of gynecologic magnetic resonance (MR) imaging on treatment decisions and net cost. MATERIALS AND METHODS: Sixty-nine consecutive women were referred for 70 pelvic MR imaging examinations. Diagnosis and treatment plans were obtained from referring physicians before and immediately after they were given verbal reports of MR imaging results. Outcome regarding treatment and symptoms was obtained at a mean follow-up of 10.9 months. RESULTS: Of 49 (71%) patients originally recommended for surgery, 36 (73%) either did not undergo surgery or less invasive surgery was performed. In 58 (84%) patients, the treatment performed was that recommended after performance of MR imaging. Symptoms resolved in 57 (83%) patients. Use of MR imaging resulted in an overall savings of $63 per patient ($1,736 per patient originally recommended for surgery). CONCLUSION: Use of pelvic MR imaging in diagnosis of some gynecologic diseases may alter treatment, decrease the number of invasive surgical procedures performed, and reduce total health care expenditures.

Adolescent↗
PubMed1994

Biobehavioral effects of weight cycling.

An association between weight cycling and mortality and morbidity has been pointed out in epidemiological studies. However, the mechanisms underlying this association are difficult to demonstrate, and earlier studies have been contradictory. In this work we investigated several mechanisms which have been suggested as possible mediators for the association between weight cycling and a number of prevalent diseases. Fat consumption, fat preference, fat distribution and metabolism, lipid profile, oral glucose tolerance test (OGTT), blood pressure and steroid hormone determinations were performed in 28 women with or without a weight cycling history, who were matched for weight and age. No differences were found between cyclers and non-cyclers for any of the behavioral, physiological, metabolical and health parameters measured, with the exception of an increase in subcutaneous abdominal fat in the cyclers. It was concluded that, in generally healthy young women, weight cycling does not differentially increase risk factors that are harmful for health. However adverse effects might still be detectable in situations where women are biologically challenged.

Adipose Tissue↗
PubMed1994

Magnetic resonance staging of neoplasms of the uterus.

The treatment of patients with uterine neoplasms may be significantly altered by the stage of disease at the time of diagnosis. A noninvasive and accurate means of staging these tumors is therefore desirable. This article discusses the magnetic resonance imaging techniques and findings that are essential for the accurate staging of uterine neoplasms. The imaging findings are presented following a discussion of the histopathologic findings, clinical presentation, diagnosis and staging, pathways of tumor spread, and treatment of each neoplasm. A comparison of magnetic resonance and other imaging techniques is also provided.

Combined Modality Therapy↗