Failure of aneurysm sac shrinkage after endovascular repair; the effect of mural calcification

AIM

To evaluate the effect of abdominal aortic aneurysm wall calcification on subsequent sac shrinkage after endovascular repair.

MATERIALS AND METHODS

Seventy-three patients underwent endovascular aneurysm repair. The degree of sac wall calcification on pre-procedural computed tomography (CT) examination was graded from 1 to 4 according to the degree of circumferential involvement. On follow-up CT imaging, the maximum transverse diameter (MTD) of the sac was recorded, as well as the presence or absence of endoleak. In those patients with a non-shrinking aneurysm, but no CT evidence of endoleak, contrast-enhanced ultrasound (USS) was performed. Any patient with an endoleak, however diagnosed, was excluded from the study. Kruskal-Wallis and Spearman's rank correlation coefficient testing was applied to compare the degree of calcification and change in MTD.

RESULTS

Sixty-three pre-procedural CT images were available for calcification grading. Six of this group had endoleaks resulting in 57 sets of data being available for the study. A reduction in MTD occurred in 68.25% of these patients by 1 year post-procedure. Our figures show aortic calcification is inversely associated with MTD reduction at 6 months (p = 0.01), 1 year (p = 0.05) and 2 years (p = 0.05).

CONCLUSION

This study indicates that the degree of aortic wall calcification is significant in predicting MTD reduction post-endovascular repair. The possible mechanisms and implications of this are discussed.

Differential modulation of withdrawal reflexes by a cannabinoid in the rabbit

Inhibition of spinal and trigeminal withdrawal reflexes by morphine and by the cannabinoid agonist HU 210 has been studied in anaesthetized and in decerebrated rabbits. In intact, pentobarbitone-anaesthetized animals, the jaw-depressor reflex (JDR) evoked by stimulation of the tongue, and the reflex elicited in the ankle flexor tibialis anterior (TA) by stimulation of the toes were inhibited to the same extent by morphine (1-30 mg kg(-1) i.v. cumulative). In spinalized, anaesthetized rabbits morphine depressed the JDR to the same level as in non-spinal preparations, but the effect of the opioid on the TA reflex was significantly reduced. All effects of morphine were reversed by naloxone (0.25 mg kg(-1), i.v.). In anaesthetised intact animals, HU 210 depressed the JDR at a dose of 100 nmol kg(-1) i.v. cumulative, reduced reflexes evoked in the knee flexor muscle semitendinosus (ST) by stimulation at the toes at a dose of 30 nmol kg(-1) i.v. cumulative, but had no consistent or significant effects on the TA reflex to toe stimulation. The same results were obtained in spinalized, anaesthetised animals. In decerebrated, spinalized rabbits with no anaesthesia, HU 210 (30 nmol kg(-1)) depressed both ST and TA reflexes evoked by toe stimulation. These data reveal that trigeminal and spinal withdrawal reflexes are equally sensitive to morphine provided the spinal cord is intact, suggesting that at least part of the action of systemic morphine is due to activation of descending inhibition. The present results also show for the first time that cannabinoid agonists can inhibit trigeminal withdrawal reflexes. HU 210 had differential effects on the three reflexes studied depending on the presence or absence of anaesthesia. This is the first occasion on which we have found pharmacological distinctions between withdrawal reflexes, and indicates that spinal sensorimotor processing is more heterogeneous than has been suspected previously.

New disc-based technologies for diagnostic and research applications

The role of genotypic analysis in disease diagnostics and drug response assessment is continually expanding. New genomic discoveries combined with new, novel technologies may provide a greater range of testing capabilities in the near future. We describe the application of nanotechnology, in which DNA microarrays have been placed in a microchannel environment that can be read and analyzed in an optical (CD/DVD) disc drive system. The potential exists to combine molecular and immunological applications together into a rapid, low-cost, high-capacity screening platform. The relevance of this technology is discussed in respect to infectious agent detection, pharmacogenomics, neurogenomics and genetic variations associated with neurologic diseases.

A case of Balamuthia mandrillaris meningoencephalitis

Balamuthia mandrillaris is a newly described pathogen that causes granulomatous amebic encephalitis, an extremely rare clinical entity that usually occurs in immunosuppressed individuals. We report a case of pathologically proven Balamuthia encephalitis with unusual laboratory and radiologic findings. A 52-year-old woman with idiopathic seizures and a 2-year history of chronic neutropenia of unknown cause had a subacute illness with progressive lethargy, headaches, and coma and died 3 months after the onset of symptoms. Cerebrospinal fluid (CSF) glucose concentrations were extremely low or unmeasurable, a feature not previously described (to our knowledge). Cranial magnetic resonance imaging scans showed a single large temporal lobe nodule, followed 6 weeks later by the appearance of 18 ring-enhancing lesions in the cerebral hemispheres that disappeared after treatment with antibiotics and high-dose corticosteroids. The initial brain biopsy specimen and analysis of CSF samples did not demonstate amebae, but a second biopsy specimen and the postmortem pathologic examination showed Balamuthia trophozoites surrounded by widespread granulomatous inflammation and vasculitis. The patient's neutropenia and antibiotic use may have caused susceptibility to this organism. Amebic meningoencephalitis should be considered in cases of subacute meningoencephalitis with greatly depressed CSF glucose concentrations and multiple nodular lesions on cerebral imaging. Arch Neurol. 2000;57:1210-1212

Multicenter evaluation of the Abbott LCx Mycobacterium tuberculosis ligase chain reaction assay

Four Australian hospital laboratories evaluated the performance of the Abbott LCx Mycobacterium tuberculosis assay with 2,347 specimens (2,083 respiratory and 264 nonrespiratory specimens) obtained from 1, 411 patients. A total of 152 specimens (6.5%) were culture positive for Mycobacterium tuberculosis complex (MTBC); of these, 79 (52%) were smear positive. After resolution of discrepant data, the overall sensitivity, specificity, and positive and negative predictive values for the LCx assay were 69.7, 99.9, 99.1, and 97.7% respectively. For smear-positive respiratory specimens that were culture positive for MTBC, the values were 98.5, 100, 100, and 98.4%, respectively, while the values for smear-negative respiratory specimens were 41.5, 99.9, 96.4, and 98%, respectively. Relative operating characteristic curves were constructed to demonstrate the relationship between sensitivity and specificity for a range of possible cutoff values in the LCx assay. These graphs suggested that the assay sensitivity for respiratory samples could be increased from 70.2 to 78.6%, while the specificity would be reduced from 99.9 to 99.4% by inclusion of a grey zone (i.e., LCx assay values of between 0.2 and 0.99). An algorithm is presented for the handling of specimens with LCx assay values within this grey zone.

Associations of smoking, alcohol and physical activity with risk factors for coronary heart disease and diabetes in the first follow-up cohort of the Heart Disease and Diabetes Risk Indicators in a Screened Cohort study (HDDRISC-1)

OBJECTIVES

To investigate the associations between risk factors for cardiovascular disease and cigarette smoking, alcohol intake, and physical activity in a group of predominantly healthy men.

DESIGN

Cohort study with baseline characterisation, clinical follow-up, and identification of predictors of coronary artery disease and diabetes.

SETTING

University hospital metabolic day ward.

SUBJECTS

Participants in a company health programme (n=742).

MAIN OUTCOME MEASURES

Routine haematology and biochemistry, cholesterol, triglycerides, high density lipoprotein (HDL) cholesterol (on a subset of 522 subjects), and glucose and insulin levels during a 3 h oral glucose tolerance test (OGTT).

RESULTS

Independent associations with previous cigarette smoking included high uric acid and low HDL cholesterol, and with current cigarette smoking, high haemoglobin and white cell count and low OGTT insulin. Increasing alcohol intake was associated with increasing blood pressure, uric acid, HDL cholesterol and fasting glucose. The moderate range of exercise intensity in this cohort was associated with decreasing systolic blood pressure, fasting insulin and OGTT glucose and insulin. Factor analysis distinguished principal factors comprising features of the metabolic syndrome with low physical activity, and high white cell count, high haemoglobin concentration and low HDL cholesterol with increasing previous and current cigarette smoking and alcohol intake.

CONCLUSIONS

Some characteristics of the metabolic syndrome were seen with previous but not current smoking habit. Regular alcohol consumption was associated with mainly unfavourable metabolic characteristics, although there was an independent beneficial association with HDL cholesterol. The improved metabolic syndrome profile seen with increasing exercise is consistent with even moderate degrees of physical activity having beneficial effects on metabolism.

Factors of the metabolic syndrome: baseline interrelationships in the first follow-up cohort of the HDDRISC Study (HDDRISC-1). Heart Disease and Diabetes Risk Indicators in a Screened Cohort

Syndromes of risk factor disturbance may contribute to the development of coronary heart disease and non-insulin-dependent diabetes mellitus, but their definition and quantification remain problematic. Using factor analysis, constellations of risk factor variables that could indicate distinct syndromes of metabolic disturbance were explored in the baseline data of the first follow-up cohort of 742 men from the Heart Disease and Diabetes Risk Indicators in a Screened Cohort (HDDRISC) study. The primary analysis considered 16 intercorrelated variables measured in more than 90% of cohort participants. A missing-values estimation routine was used to ensure inclusion of all participants in the analysis. Subanalyses were undertaken, including a repeat of the primary analysis on the 522 individuals who had received measurement of HDL cholesterol, an oblique rather than orthogonal factor rotation procedure performed on primary and HDL subset analyses, a repeat of these two primary and HDL subset analyses using only those participants with complete measurements, and a repeat of these six analyses including only the seven variables conventionally associated with the metabolic syndrome. The principal factor that emerged in all analyses undertaken comprised oral glucose tolerance test insulin and glucose response, serum uric acid, and body mass index. Fasting serum triglyceride concentration was included in this factor in 11 of the 12 analyses undertaken, fasting plasma insulin in 8, fasting plasma glucose in 5, and mean arterial pressure in 3. HDL cholesterol factored in isolation from insulin in all analyses undertaken. These findings provide strong support for a core metabolic cluster, which is unlikely to include blood pressure and does not include HDL. The factor scores relating to this cluster will provide a means of assessing its quantitative importance in prospective analysis of the development of CHD and diabetes in this cohort.

New solution for prolonged myocardial preservation for transplantation

BACKGROUND

A solution for prolonged cold storage of the heart has been developed. The Jerusalem-Cape Town Solution (JCT) is an "intracellular" type cardioplegic solution and is formulated to (1) minimize hypothermic-induced cell swelling, (2) diminish intracellular acidosis, (3) prevent the expansion of the interstitial space during the reperfusion, (4) protect against oxygen free radical injury during early reperfusion, and (5) provide substrates for regenerating high-energy phosphates.

METHODS

With a Langendorff model, rat hearts were subjected to 15 minutes of perfusion with Krebs-Henseleit, 10 minutes of cardioplegic infusion and 20 hours of cold storage (5 degrees to 6 degrees C). Hearts were reperfused for 60 minutes and hemodynamic recovery was assessed. The hearts were assigned to three groups (eight hearts in each), according to the cardioplegic solution used: group 1, JCT; group 2, Bretschneider's HTK cardioplegic solution; and group 3 University of Wisconsin cold storage solution.

RESULTS

After 60 minutes of reperfusion, the recovery of the coronary artery flow in group 1 (JCT) was significantly better than in group 2, and slightly better than in group 3 (64% +/- 8.9%, 47.2% +/- 11.6%, 52.5% +/- 19.9%, mean +/- SD, respectively; group 1 versus group 2, p < 0.01). The recovery of the left ventricular developed pressure (LVDP) was significantly better in group 1 compared with group 2 and group 3 (60.2% +/- 14.5%, 41.1% +/- 12.6% and 36.5% +/- 10.1%, respectively; p < 0.01). The recovery of the heart contractility expressed by the product of LVDP and the heart rate (LVDP x heart rate) was significantly higher in group 1 than in group 2 and group 3 (47.5% +/- 3.4%, 23.6% +/- 9.6%, and 28.7% +/- 8.3%, respectively, p < 0.001). In hearts stored for 12 hours in JCT or HTK, the recovery of the heart contractility did not differ significantly (73.4% +/- 12.7% or 70.8% +/- 30.8%, respectively). Modified reperfusion aimed to improve postischemic heart recovery did not bring significant changes in cardiac mechanical function but resulted in an increase in postischemic coronary artery flow recovery in hearts reperfused with amino acid-enriched buffer.

CONCLUSIONS

The JCT solution is effective (as well as HTK) in preserving the ischemic hearts for up to 12 hours. It is superior to HTK or University of Wisconsin solution at 20 hours of isolated ischemic storage.

Cytomegalovirus colitis mimicking colon carcinoma in an HIV-negative patient with chronic renal failure

Cytomegalovirus (CMV) colitis is thought to occur almost exclusively in immunosuppressed persons. Colonoscopy in patients with CMV colitis usually shows diffuse or localized ulceration, although mucosal friability, erosions, hemorrhage, and plaque-like pseudomembranes may be observed. We report on a patient with chronic renal failure undergoing hemodialysis therapy who had abdominal symptoms, including bloody diarrhea, along with colonoscopic findings suggestive of carcinoma of the colon. The patient was not infected with the human immunodeficiency virus and had normal lymphocyte subset numbers. He was subsequently found to have invasive CMV disease of the colon. CMV colitis can occur in persons who are not severely immunosuppressed, and its colonoscopic appearance may mimic that of colon cancer.

Body fat distribution, rather than overall adiposity, influences serum lipids and lipoproteins in healthy men independently of age

PURPOSE

We investigated the relationships between the amount and distribution of body fat and fasting serum lipids and lipoproteins to explore whether coronary artery disease (CAD) risk may be mediated through effects on the serum lipid profile.

PATIENTS AND METHODS

We determined serum total cholesterol and triglyceride, low-density lipoprotein cholesterol, high-density lipoprotein (HDL) cholesterol, and HDL subfractions 2 and 3 in 103 healthy men, aged 21 to 77 years (mean 48.7). The amount and distribution of fat were determined directly by dual energy X-ray absorptiometry. Adiposity was determined as the ratio between total body fat tissue and total body lean tissue, while fat distribution was taken as the ratio between the mass of fat tissue in the android (central) and gynoid (hip and thigh) regions.

RESULTS

Univariate analysis showed both adiposity and fat distribution to be correlated with total serum cholesterol and triglyceride concentrations (adiposity r = .20, .21; both P < 0.05: fat distribution r = .25, .38; P < 0.05, P < 0.001, respectively). Fat distribution was also negatively correlated with HDL2 cholesterol (r = -.20, P < 0.05). In multiple linear regression analysis, neither age nor adiposity was significantly correlated with any serum lipid or lipoprotein concentration, while increasing android-to-gynoid ratio was independently associated with elevated total serum triglyceride (r = .40, P < 0.01) and decreased HDL2 (r = -.25, P < 0.05) concentrations.

CONCLUSIONS

The association of both age and overall adiposity with the fasting serum lipid profile are mediated via their correlations with body fat distribution. In men, the distribution, rather than the amount, of body fat is related to adverse changes in serum lipids and lipoproteins, and hence potentially to increased CAD risk.

Spectrum and significance of bacteremia due to Moraxella catarrhalis

Fifty-eight cases of bacteremia due to Moraxella catarrhalis, including seven that occurred in patients treated at our facilities, are analyzed. The host's medical history plays a major role in the presentation and outcome of M. catarrhalis bacteremia. Bacteremia is typically accompanied by pneumonia in adults with underlying respiratory disease. Many neutropenic patients do not manifest a focus of infection; in contrast, the source identified in healthy, immunocompetent patients is usually the upper airway or the ears. In the recent literature, it has been reported that a rash is typically absent in adults with bacteremic pneumonia and in immunocompetent hosts and that only some neutropenic patients have a rash. The prognosis is grave for patients with endocarditis and for patients with immunoglobulin deficiency or neutropenia not related to a hematologic malignancy. In addition, mortality is substantial among bacteremic patients with respiratory conditions or other chronic debilities, especially when respiratory copathogens are present. The prognosis is good for febrile neutropenic patients with underlying leukemia or lymphoma when the neutropenia resolves. When healthy, immunocompetent individuals are affected with M. catarrhalis bacteremia, their presentations range from self-limited febrile illness to life-threatening disease.

Effect of continuous combined estrogen and desogestrel hormone replacement therapy on serum lipids and lipoproteins

OBJECTIVE

To determine the effects of continuous combined hormone replacement therapy with desogestrel and 17 beta-estradiol (E2) on serum lipids and lipoproteins.

METHODS

Fifty-seven healthy postmenopausal women of less than 60 years of age were studied prospectively and treated with oral desogestrel 0.15 mg/day and micronized 17 beta-E2 1 mg/day, both taken continuously. Fasting venous blood samples for serum lipids and lipoproteins were taken before and after 6 and 12 months of treatment.

RESULTS

Thirty-two women completed the study. Levels of all serum lipids and lipoproteins fell significantly by 6 months and remained low at 12 months. The mean percentage reduction after 12 months of treatment was 12.8% for high-density lipoprotein (HDL) cholesterol, which largely resulted from a reduction in the HDL2 subfraction, which fell by 25.7%. The mean percentage reduction for both low-density lipoprotein (LDL) cholesterol and triglycerides was 7.7%. The median percentage reduction for lipoprotein (a) was 17.6%.

CONCLUSIONS

This combination of hormone replacement therapy had profound effects on serum lipids and lipoproteins. According to current concepts, reductions in total and LDL cholesterol, triglycerides, and lipoprotein (a) may reduce cardiovascular disease risk. The reduction in HDL was unexpected, given the rise in HDL that has been demonstrated when desogestrel is combined with ethinyl estradiol in the contraceptive pill. The lowering of HDL observed in this study is undesirable and may be potentially harmful. Our results indicate that when desogestrel 0.15 mg/day is combined with micronized 17 beta-E2 1 mg/day in a continuous manner, the effects of the progestogen on HDL predominate and cause a reduction in HDL and the HDL2 subfraction.

A comparative metabolic study of two low-estrogen-dose oral contraceptives containing desogestrel or gestodene progestins

OBJECTIVES

Our objective was to compare the effects of low-estrogen-dose oral contraceptives containing desogestrel or gestodene progestins on metabolic risk markers for coronary heart disease.

STUDY DESIGN

A cross-sectional comparison of 70 women who used a formulation that contained 30 micrograms ethinyl estradiol and 150 micrograms desogestrel, 43 women who used a formulation that contained 30 micrograms ethinyl estradiol and 75 micrograms gestodene, and 54 women who did not use steroidal contraceptives was performed.

RESULTS

Oral contraceptive users had higher concentrations of high-density lipoproteins than did women in the control group (+10% to +20%, p < 0.001) primarily because of increases in high-density lipoprotein subfraction 3. High-density lipoprotein subfraction 2 concentrations were higher in users of the desogestrel formulation. Low-density lipoprotein cholesterol concentrations were normal in oral contraceptive users, but triglyceride concentrations were high (+80% to +100%, p < 0.001). Fasting glucose, insulin, and C-peptide concentrations were similar in the three groups, but their responses to a glucose load were higher in oral contraceptive users than in controls (p < 0.01 to p < 0.001). The late plasma insulin response to glucose was higher in the women who used the gestodene formulation than in those who used the desogestrel formulation.

CONCLUSIONS

The metabolic profiles induced by these oral contraceptives were remarkably similar and may reflect the activity of the estrogen component.

Effects of a low-estrogen, desogestrel-containing oral contraceptive on lipid and carbohydrate metabolism

Fasting serum lipids, lipoproteins and apolipoproteins, and fasting plasma glucose, insulin and C-peptide were measured in 107 non-users and 83 users of an oral contraceptive containing the progestin desogestrel, combined with 20 micrograms ethinyl estradiol. Plasma glucose, insulin and C-peptide concentrations during an oral glucose tolerance test (OGTT) were measured in a subgroup of 69 non-users and 39 users. Compared with non-users, users had higher concentrations of total, high density lipoprotein (HDL), HDL subfraction 3 and very low density lipoprotein (VLDL) cholesterol, total triglycerides, VLDL triglycerides, apolipoproteins AI and AII and fasting plasma insulin. There were no differences in HDL subfraction 2, low density lipoprotein cholesterol and apolipoprotein B. OGTT glucose was 60% higher in the users and OGTT insulin response 19% higher. The OGTT C-peptide response did not differ. The effects of 20 micrograms ethinyl estradiol combined with 150 micrograms desogestrel on lipid, lipoprotein, glucose and insulin metabolism are similar to those described previously with a 30 micrograms ethinyl estradiol combination containing the same dose of desogestrel. The relatively favourable metabolic profile associated with the higher estrogen dose desogestrel combination is maintained at the lower dose.

A randomized comparative study of the metabolic effects of two regimens of gestrinone in the treatment of endometriosis

OBJECTIVE

To study some of the metabolic effects of oral gestrinone on plasma lipoprotein risk markers for cardiovascular disease and on bone density, a risk marker for osteoporosis.

DESIGN

Randomized double-blind study.

SETTING

All patients were referred to Gynaecology Clinic of Royal Free Hospital Medical School.

PATIENTS

Twenty premenopausal women with laparoscopically confirmed endometriosis.

INTERVENTIONS

Subjects were randomized in a double-blind fashion to receive either 1.25 mg or 2.5 mg gestrinone two times per week for 6 months.

MAIN OUTCOME MEASURE

Laparoscopy was performed before treatment, and clinical responses were determined by second laparoscopy after 6 months. Plasma lipid and bone density measurements during and after therapy were compared with baseline.

RESULT

Median total endometriosis scores decreased from 7.5 to 1.0 in the 1.25-mg group and from 7.0 to 0 in the 2.5-mg group. There were no significant between-group differences in endometriosis scores. At both doses, bone density in the spine and the proximal femur was conserved, but plasma concentrations of low-density lipoproteins rose by 13% and those of high-density lipoproteins fell by 40%.

CONCLUSIONS

Reducing the dose of gestrinone to 1.25 mg appeared to maintain the therapeutic effectiveness of this treatment but was still associated with potentially unfavorable effects on lipids and lipoproteins.

Effect of simvastatin on high density lipoprotein subfractions and apolipoproteins in type IIa hypercholesterolemia

Changes in plasma concentrations of high density lipoproteins (HDL) and triglycerides may partly explain the ability of cholesterol-lowering drugs to decrease the incidence of coronary heart disease. We measured the response of fasting plasma lipids, lipoproteins, and apolipoproteins in 46 subjects with Type IIa hypercholesterolemia treated with simvastatin for 3 months. The initial dose of simvastatin (10 mg/day) was subsequently increased up to 40 mg/day if the plasma cholesterol concentration had not fallen below 5.2 mmol/l. Plasma concentrations of HDL cholesterol and of the apolipoproteins AI and AII were increased by simvastatin. The increase in HDL cholesterol (9%) was due to increases in both subfractions (HDL2 17%; HDL3 7%), changes that would be consistent with a beneficial effect on cardiovascular risk. Simvastatin decreased plasma triglyceride concentrations by 25%. Plasma total cholesterol concentrations fell by 35% after 3 months of treatment; this fall was proportional to the initial concentration and was due almost entirely to a 45% fall in low density lipoprotein cholesterol. In contrast, plasma concentrations of lipoprotein Lp(a) were not affected by simvastatin.

Comparison of transdermal and oral estrogen-progestin replacement therapy: effects on serum lipids and lipoproteins

OBJECTIVE

We attempted to ascertain whether transdermal postmenopausal estrogen-progestin therapy has the typical effects of oral therapy on serum lipoprotein risk markers for cardiovascular disease.

STUDY DESIGN

Sixty-one postmenopausal women were randomized to receive either transdermal continuous 17 beta-estradiol, 0.05 mg/day, with transdermal cyclic norethindrone acetate, 0.25 mg/day, or oral continuous conjugated equine estrogens, 0.625 mg/day, with oral cyclic dl-norgestrel, 0.15 mg/day. Twenty-nine untreated subjects served as controls. Lipoprotein profiles at 3 and 6 months were compared with baseline values by means of analysis of variance.

RESULTS

In the estrogen-alone phase both therapies reduced serum levels of total and low-density lipoprotein cholesterol; high-density lipoproteins were largely unchanged. Oral therapy increased triglycerides whereas this lipid fell with transdermal therapy. In the combined phase of the cycle both therapies reduced triglycerides, total cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol.

CONCLUSION

Transdermal and oral therapies had similar effects on lipoprotein cholesterol but different effects on triglycerides.