Biomedical subjects

Mireya Diaz

Publications and source records attributed to Mireya Diaz.

7 recordsLinked to original sources

PubMed2006

Endoscopic therapy for vesicoureteral reflux: a meta-analysis. I. Reflux resolution and urinary tract infection.

PURPOSE: Current American Urological Association treatment guidelines for vesicoureteral reflux do not include any recommendations pertaining to endoscopic therapy (subureteral injection of bulking agent). We performed a meta-analysis of the existing literature pertaining to endoscopic treatment to allow comparison with reports of open surgical correction. MATERIALS AND METHODS: We searched all peer reviewed articles published through 2003 pertaining to endoscopic treatment of vesicoureteral reflux. A total of 63 articles were double reviewed by 9 pediatric urologists, and the data were tabulated on data retrieval sheets. A mixed effects logistic regression model was used to obtain overall estimates of event probabilities (eg reflux resolution, ureteral obstruction) together with their 95% confidence intervals. Individual study estimates were obtained with overall estimate and observation characteristics using empirical Bayes calculations. Differences between or among specific groups were assessed using the F-test. RESULTS: The database included 5,527 patients and 8,101 renal units. Following 1 treatment the reflux resolution rate (by ureter) for grades I and II reflux was 78.5%, grade III 72%, grade IV 63% and grade V 51%. If the first injection was unsuccessful, the second treatment had a success rate of 68%, and the third treatment 34%. The aggregate success rate with 1 or more injections was 85%. The success rate was significantly lower for duplicated (50%) vs single systems (73%), and neuropathic (62%) vs normal bladders (74%). The success rate was similar among children and adults. Following a previous failed open reimplantation endoscopic treatment was successful in 65% of patients. After endoscopic treatment with variable followup pyelonephritis developed in 0.75% of patients and cystitis in 6%. There were few reports of renal scarring following treatment. CONCLUSIONS: Endoscopic treatment provides a high rate of success in children with reflux that decreases with increasing grade, although multiple treatments may be necessary. Future reports of endoscopic therapy should include rates of urinary tract infection and renal scarring.

Child↗

PubMed2006

Retractile testis--is it really a normal variant?

PURPOSE: Retractile testes are thought to represent a normal variant of descended testes in prepubertal boys. We studied retractile testes to determine their natural history. MATERIALS AND METHODS: We retrospectively reviewed the charts of 122 boys (mean age 5.4 years) who were referred for a suspected undescended testis and were found to have a retractile testis. A retractile testis was defined as a suprascrotal testis that could be manipulated easily into the scrotum and remained there without traction until the cremasteric reflex was induced. The boys were followed by annual examinations, which demonstrated the presence of retractile, descended (nonretractile) or undescended testes, and the presence or absence of a taut or inelastic spermatic cord in association with a retractile testis. RESULTS: Of 204 retractile testes 61 (30%) descended (became nonretractile), 66 (32%) became UDTs and 77 (38%) remained retractile. Of the 62 retractile testes with a taut or inelastic spermatic cord 35 (56%) became UDTs. Of the 61 orchiopexies performed 8 (13%) showed a patent processus vaginalis. Boys in whom UDTs vs descended testes developed were a mean of 4.9 vs 6.6 years old (p = 0.001). The chance of spontaneous descent was 58% in boys 7 years or older, compared to 21% in boys younger than 7 (p <0.0001). CONCLUSIONS: A retractile testis is not a normal variant. Retractile testes have a 32% risk of becoming an ascending or acquired undescended testis. The risk is higher in boys younger than 7 years old, or when the spermatic cord seems tight or inelastic. Boys with retractile testes should be monitored annually until the testes have clearly descended.

Adolescent↗

PubMed2005

The effect of single-detector CT versus MDCT on clinical outcomes in patients with suspected acute pulmonary embolism and negative results on CT pulmonary angiography.

OBJECTIVE: We sought to compare the clinical outcomes of patients in whom pulmonary embolism (PE) has been ruled out with single-detector CT versus MDCT, given the improved visualization of subsegmental clots with the latter and the recent increase in use of CT for evaluation of PE. SUBJECTS AND METHODS: Two cohorts of patients undergoing CT for suspected PE with either single-detector CT (3-mm collimation and pitch of 1.7) or MDCT (2-mm collimation and pitch of 1) scanners were prospectively observed and compared using predefined criteria for evidence of subsequent thromboembolic disease during the 6 months after the acquisition of their initial scan. RESULTS: Ninety-eight patients were scanned using a single-detector CT scanner. Of these, none had evidence of subsequent PE or deep venous thrombosis (DVT), and six (6.1%) died of unrelated causes. Of the 100 patients scanned using an MDCT scanner, one (1.0%) had a subsequent nonfatal PE 2 months after the initial scanning, one (1.0%) had DVT 1 month after the initial scanning, and eight (8.0%) died of unrelated causes. No significant difference was found in either the probability of subsequent thromboembolic events (chi(2) = 0.3183, degrees of freedom [df] = 1, p = 1) or frequency of unrelated deaths (chi(2) = 0.2655, df = 1, p = 0.7829) between patients scanned using single-detector CT or MDCT protocols. CONCLUSION: Our results show that patients with suspected acute PE and negative CT results have acceptable clinical outcomes in the absence of anticoagulation treatment up to 6 months after acquisition of their initial scan. Furthermore, we found that the increased visualization of smaller, more peripheral arteries afforded by multislice technology did not affect clinical outcome.

Adolescent↗

PubMed2004

Regulation of malonyl-CoA concentration and turnover in the normal heart.

The goal of this study was to test the relationship between malonyl-CoA concentration and its turnover measured in isolated rat hearts perfused with NaH(13)CO(3). This turnover is a direct measurement of the flux of acetyl-CoA carboxylation in the intact heart. It also reflects the rate of malonyl-CoA decarboxylation, i.e. the only known fate of malonyl-CoA in the heart. Conditions were selected to result in stable malonyl-CoA concentrations ranging from 1.5 to 5 nmol.g wet weight-(1). The malonyl-CoA concentration was directly correlated with the turnover of malonyl-CoA, ranging from 0.7 to 4.2 nmol.min(-) (1).g wet weight(-1) (slope = 0.98, r(2) = 0.94). The V(max) activities of acetyl-CoA carboxylase and of malonyl-CoA decarboxylase exceeded the rate of malonyl-CoA turnover by 2 orders of magnitude and did not correlate with either concentration or turnover of malonyl-CoA. However, conditions of perfusion that increased acetyl-CoA supply resulted in higher turnover and concentration, demonstrating that malonyl-CoA turnover is regulated by the supply of acetyl-CoA. The only condition where the activity of malonyl-CoA decarboxylase regulated malonyl-CoA kinetics was when the enzyme was pharmacologically inhibited, resulting in increased malonyl-CoA concentration and decreased turnover. Our data show that, in the absence of enzyme inhibitors, the rate of acetyl-CoA carboxylation is the main determinant of the malonyl-CoA concentration in the heart.

Acetyl Coenzyme A↗

PubMed2004

A meta-analysis of controlled studies comparing major malformation rates in IVF and ICSI infants with naturally conceived children.

PURPOSE: To estimate the risk of major malformations in IVF and ICSI infants. METHODS: Forty-four studies published in English since 1990 where the major malformation rate for IVF or ICSI cases was compared to an appropriate control group were reviewed. Nineteen studies met all selection criteria. In addition, a quality score was developed to assess each study based on sample size, timing of diagnosis, appropriateness of control group and other factors. RESULTS: In 19 studies, the major malformation rates ranged from 0-9.5% for IVF; 1.1-9.7 for ICSI; and 0-6.9% in the control groups. When ICSI was compared to IVF, and multiple births compared to singleton, there were no statistically significant differences. When data from 16 studies involving 28,524 IVF infants and 2,520,988 spontaneously conceived controls and 7 studies involving 7234 ICSI infants and 978,078 controls were pooled, we found an overall odds ratio for the 19 studies of 1.29 (95% CI 1.01-1.67). CONCLUSIONS: The overall odds ratio of 1.29 was statistically significant at the 5% level. These results may be useful for counseling ART patients and properly designing the consent forms used for ART procedures. It is not clear whether this risk is due to the procedures used in ART. We found that some of these studies have design flaws. All of them lacked an appropriate control group, i.e. infertile patients conceiving spontaneously. These flaws may create biases that would in almost all instances increase the risk of major malformations in the study group. Further research with better designed studies will likely result in a better estimate of the risk of major malformations associated with IVF and ICSI.

Congenital Abnormalities↗

PubMed2004

CT pulmonary angiography: a comparative analysis of the utilization patterns in emergency department and hospitalized patients between 1998 and 2003.

OBJECTIVE: The purpose of our study was to objectively examine the temporal utilization patterns of CT pulmonary angiography in emergency department and hospitalized patients in an academic tertiary care center. SUBJECTS AND METHODS: Patients who underwent CT examination for suspected pulmonary embolism either through our emergency department or as inpatients during a recent 9-month interval were identified. The absolute number of studies and incidence of positive results and ancillary findings were compared with similar data published from our institution during the corresponding 9-month interval in 1997-1998. RESULTS: The overall number of patients imaged for pulmonary embolism was significantly greater in the 2002-2003 period than in the 1997-1998 period (homogeneity of rates = 88.45, p < 0.0001). The absolute number of scans obtained was significantly greater in both the emergency department (chi(2) = 167.03, p < 0.0001) and inpatient (chi(2) = 210.62, p < 0.0001) groups in the more recent population. Significantly fewer ancillary findings were reported in both the emergency department (chi(2) = 5.93, p = 0.019) and inpatient (chi(2) = 6.03, p = 0.015) groups in the more recent population. The incidence of CT-detected pulmonary embolism was significantly less in both the emergency department (chi(2) = 34.26, p < 0.0001) and inpatient (chi(2) = 8.52, p < 0.01) groups in the more recent population. This decrease in the incidence of scans with positive findings for pulmonary embolism over time was significantly greater in the emergency department group than the inpatient group (homogeneity of odds = 0.003, p < 0.007). CONCLUSION: The evolution of CT pulmonary angiography utilization has led to a significant increase in the number of patients being imaged for pulmonary embolism with a coincident significant decrease in the rates of CT-detected pulmonary embolism and ancillary findings both in emergency department and hospitalized patients.

Adult↗

PubMed2003

T cells containing T cell receptor excision circles are inversely related to HIV replication and are selectively and rapidly released into circulation with antiretroviral treatment.

OBJECTIVE: To examine baseline predictors of T-cell receptor rearrangement excision circle (TREC) levels and their changes during treatment with combined antiretroviral therapy. METHODS: Peripheral blood and lymph node lymphocytes were examined for the presence of TREC by real-time polymerase chain reaction and circulating lymphocyte phenotypes were examined by flow cytometry. Correlates for CD4 and CD8 cell TREC levels at baseline were identified among CD4 and CD8 immunophenotypes, viral load and patient demographics; the significance of TREC changes after initiation of antiretroviral therapy was assessed. RESULTS: Circulating TREC levels correlated inversely with age, with HIV RNA levels, with activation markers on circulating T cells and with naive CD4 but not CD8 cell frequencies. With initiation of antiretroviral therapy, TREC and naive T cell frequencies increased in peripheral blood during the first 2 weeks of treatment and these changes correlated negatively with TREC frequencies in lymph node aspirates, particularly among CD8 T cells. CONCLUSIONS: These findings suggest that recent thymic emigrants are sequestered in lymphoid tissue during uncontrolled HIV replication and are selectively released into circulation rapidly after initiation of antiretroviral therapies.

Adult↗