Biomedical subjects

Michael Huerta

Publications and source records attributed to Michael Huerta.

At least 19 recordsLinked to original sources

PubMed2007

A radiological study on the anatomical proximity of the ureters and the cervix.

In order to evaluate risk factors for anatomical proximity between the cervix and the ureters the distance between the ureters and the cervix was measured in 499 computerized tomography (CT) studies at the most dorsal reflection of the ureters. The relationship between the ureter-cervical distance and the presence of pelvic pathology was assessed by correlation tests and regression analysis. Of the 499 CT studies, 252 demonstrated radiographic pathologies. Among abnormal scans, 126 (50%) involved cervical pathology. At least one ureter was within 0.5 cm of the cervix in 3.6% of patients with normal CT scans and in 10.3% of patients with cervical pathology. Overall, the right ureter was significantly closer to the cervix than the left (2.0 +/- -0.8 cm vs. 2.2 +/- 1.0 cm, p < 0.05). In cases were the pathology was limited to the cervix, the right ureter was more distant than the left (2.0 +/- 0.6 cm vs. 1.7 +/- 0.6 cm, p < 0.05). The distance between the ureters and the cervix was inversely correlated with the lateral diameter of the cervix (r = 0.18, p < 0.001) and its anterior-posterior diameter (r = 0.11, p < 0.001). Age did not correlate with the distance of the ureters from the cervix (r = 0.002, p = N.S). In conclusion, approximately 10% of patients with cervical pathology can be expected to have a ureter proximate less than 5 mm from the cervix. For patients with cervical pathology undergoing a planned hysterectomy, preoperative measurement of cervical-ureteric distance may be warranted. In these circumstances intra-operative measures to protect the ureter and ascertain its integrity may be invaluable.

Adult↗

PubMed2006

Perioperative predictors of successful hysteroscopic endometrial ablation.

OBJECTIVE: To determine which perioperative factors influence the success of hysteroscopic endometrial ablation in patients with menorrhagia. STUDY DESIGN: A longitudinal study of 128 women who underwent hysteroscopic endometrial ablation or resection. Clinical data included age, uterine size, the presence of intramural or submucosal myomas and polyps, and length of follow-up from initial hysteroscopic ablation to re-ablation or hysterectomy ('failure'). Kaplan-Meier survival analysis, log-rank tests and Cox proportional hazard regression were used to evaluate the equality of survival distributions and to model the overall effects of the various predictor variables on surgical outcomes. RESULTS: Patients were followed for a median time of 44 months. Thirteen women (10.2%) underwent a second operative procedure. Multivariate analysis identified submucosal myoma as a statistically significant positive predictor of the risk of failure [hazard ratio (HR) 5.22, 95% confidence interval (CI) = 1.63, 16.73)]. Older age was associated with a marginally lower risk of subsequent surgery (HR 0.90 per additional year of age, 95% CI = 0.81, 1.00). CONCLUSIONS: The presence of submucosal myoma increases the risk of subsequent surgery in patients undergoing endometrial ablation.

Adult↗

PubMed2006

Appropriateness of US and international BMI-for-age reference curves in defining adiposity among Israeli school children.

Effective surveillance of trends in paediatric overweight and obesity requires the establishment of valid cutoff values to identify children at risk. In Israel, standard values for childhood BMI-for-age are currently based on growth charts published by the US Centers for Disease Control and Prevention. However, the appropriateness of using US reference values in populations outside the US is questionable, due to inherent differences in ethnicity, culture and socioeconomic status. We recorded data from 9,988 children aged 6-12 selected by random cluster sampling within the framework of school-based health surveys conducted in Israel during the years 1997 and 2000. We constructed population-specific centile BMI-for-age curves valid for Israeli children, and compared these curves to current standard US and international reference values. Curves were constructed using LMS statistical curve smoothing methods. The data set of Israeli schoolchildren produced reference centiles substantially different than those based on US children. Israeli reference values were closer to centile curves published by the International Obesity Task Force. In conclusion, local and national health planners should recognize the intrinsic limitations associated with the use of "standard" reference values in defining paediatric overweight and obesity in dissimilar populations. The results of this large population-based study highlight the need for population-specific BMI-for-age reference values, in order to accurately describe the prevalence of paediatric overweight and obesity.

Body Mass Index↗

PubMed2006

Declining population immunity to mumps among Israeli military recruits.

Population-based seroepidemologic data on mumps have not been available in Israel since 1987, and the effects of mass immigration from the Commonwealth of Independent States during the 1990s have not been investigated. We conducted a seroprevalence study of mumps antibodies among 353 Israeli military recruits aged 18-19, based on a representative sample of sera collected in 1999. The overall seroprevalence rate was 83.3%, which was significantly lower than that measured in 1987 (94.1%, P<0.001). Foreign-born subjects had substantially lower seroporevalence rates than their native Israeli counterparts (68.5% versus 86.1%, P<0.001). Recent seroprevalence levels are below those required for herd immunity, and most likely contributed to an outbreak of mumps observed among young adults in Israel in 2005. Immigration appears to be a contributing factor to the decrease in population seroprevalence over time.

Antibodies, Viral↗

PubMed2006

Prevalence of prehypertension and associated cardiovascular risk profiles among young Israeli adults.

Recently the Joint National Committee on the Prevention, Detection, Evaluation, and Treatment of High Blood Pressure introduced the term "prehypertension" for systolic blood pressure levels of 120 to 139 mm Hg and diastolic BP levels of 80 to 89 mm Hg. Little is known about the prevalence of this entity and the cardiovascular risk factors associated with it. We aimed to determine the prevalence of prehypertension and the cardiovascular risk factors associated with it in a large population-based sample of young Israeli adults. We studied 36,424 Israel Defense Forces employees during the years 1991 to 1999. Subjects completed a detailed questionnaire and underwent physical examination, and blood samples were drawn after a 14-hour fast. Prehypertension was defined as a systolic blood pressure of 120 to 139 mm Hg, and/or a diastolic blood pressure of 80 to 89 mm Hg. We calculated the age- and sex-specific prevalence of prehypertension and other cardiovascular risk factors associated with this condition. Prehypertension was observed among 50.6% of men and 35.9% of women. The prehypertensive group had higher levels of blood glucose, total cholesterol, low-density lipoprotein cholesterol, and triglycerides, higher body mass index, and lower levels of high-density lipoprotein cholesterol than did the normotensive group. Multivariate logistic regression analysis showed that body mass index was the strongest predictor of prehypertension among both males and females (odds ratio, 1.100; 95% CI, 1.078 to 1.122 and odds ratio, 1.152; 95% CI, 1.097 to 1.21, respectively, for every 1 kg/m2 increase). Our findings support the recommendation of lifestyle modification for prehypertensive patients. Further prospective studies are required to determine the role of pharmacotherapy in prehypertension.

Adult↗

PubMed2006

Long-term immunity in young adults after a single dose of inactivated Hepatitis A vaccines.

We evaluated in a prospective study the immune response of naïve subjects to a single dose of inactivated Hepatitis A vaccine. Ninety-seven percent of the vaccinees sero-converted 1 month after vaccination and 93% were still positive 2 years later. All of the vaccinees had a strong booster response 2 years after the single dose. Avaxim was more immunogenic than Vaqta for the primary dose (p = 0.01 for sero-positivity, p<0.001 for antibody level) but no differences were found after boosting with Avaxim. Performance of intense physical activity during the first month after a single vaccine dose was associated with lower antibody levels (p = 0.004). This study indicates that a single dose of inactivated HAV vaccine elicits protective immune memory for at least 2 years.

Adolescent↗

PubMed2006

Parental smoking and education as determinants of overweight in Israeli children.

INTRODUCTION: Obesity is a well-recognized risk factor for many chronic diseases. Pediatric overweight is an especially severe problem because its childhood onset increases the overall length of exposure to the detrimental effects of overweight, accelerates the onset of chronic disease, and affects children's physical, psychological, and social development. Several parental traits have been shown to be associated with an increased risk for childhood overweight. In our study, we quantified the mutual effects of parental education and smoking on the risk of filial overweight in a large population-based sample of Israeli schoolchildren, adjusting for the effects of age, sex, and immigration status. METHODS: Data were collected in 1997 and 2000 from 8623 Israeli schoolchildren aged 8 to 13 years in two cross-sectional samples. Overweight was defined as body mass index (BMI) of greater than the 85th percentile for age and sex, and severe overweight was defined as BMI greater than the 95th percentile for age and sex. RESULTS: Mean BMI was positively associated with number of parental smokers for a child. Parental smoking was an independent risk factor for both overweight and severe overweight, with a dose-response relationship between the number of parental smokers and the risk of filial overweight. Children whose parents did not attend college were at increased risk for overweight (odds ratio [OR], 1.21; 95% confidence interval [CI], 1.03-1.42) and severe overweight (OR, 1.49; 95% CI, 1.09-2.05) compared with children whose parents both attended college. Children with one college-educated parent were at increased risk for severe overweight (OR, 1.31; 95% CI, 1.004-1.71) compared with children whose parents both attended college. CONCLUSION: Parental education and smoking are independent risk factors for filial overweight. Children of less-educated, smoking parents should be targeted for overweight prevention and intervention efforts. These findings should also be included as key messages in adult smoking prevention and cessation campaigns. Parents who smoke should be warned that not only is their own health at stake, but their children are also at increased risk for overweight and its associated diseases.

Adolescent↗

PubMed2006

Ten-year trends in obesity among Israeli schoolchildren: 1990-2000.

AIM: To analyze trends in childhood body mass index (BMI) in Israel between 1990 and 2000, and to determine the proportion of obese children using US and population-specific reference values. METHODS: Cross-sectional data from 13 284 second- and fifth-grade schoolchildren were collected, including age, sex, height, weight, country of birth, and time since immigration. Age- and sex-specific BMI means and centiles were calculated, and the prevalence of obesity was determined using Israeli and US reference values. RESULTS: BMI values at the 95th centile increased monotonously over time in all age and sex categories. Between 1990 and 2000, 95th centile values increased by 12.7% and 11.8% among second-grade boys and girls, respectively. Among fifth-grade children, 95th centile values increased by 10.2% and 8.4%, respectively. Among second graders in 2000, 11.4% of both boys and girls exceeded the BMI value recorded at the 95th centile in 1990. Among fifth-graders in 2000, 10.7% of boys and 11.1% of girls exceeded the 1990 BMI reference value (p for all comparisons < 0.001). The proportion of obese children increased over time using both Israeli and US reference values. CONCLUSION: This substantial increase in childhood obesity poses a serious health threat, and requires implementation of suitable public health interventions.

Age Distribution↗

PubMed2006

Evaluation of arterial compliance in polycythemia vera patients: short and long-term influence of phlebotomy.

BACKGROUND: Thrombosis is a major cause of morbidity and mortality in polycythemia vera. Hypercoagulability is principally due to hyperviscosity of the whole blood, an exponential function of the hematocrit. PV is also associated with endothelial dysfunction that can predispose to arterial disease. Reduction of the red cell mass to a safe level by phlebotomy is the first principle of therapy in PV. This therapy may have some effect on the arterial compliance in PV patients. OBJECTIVES: To estimate the influence of phlebotomies on large artery (Cl) and small artery compliance (C2) in PV patients by using non-invasive methods. METHODS: Short-term hemodynamic effects of phlebotomy were studied by pulse wave analysis using the HDI-Pulse Wave CR2000 (Minneapolis, MN, USA) before and immediately after venesection (350-500 ml of blood). We repeated the evaluation after 1 month to measure the long-term effects. RESULTS: Seventeen PV patients were included in the study and 47 measurements of arterial compliance were performed: 37 for short-term effects and 10 for long-term effects. The mean large artery compliance (C1) before phlebotomy was 12.0 ml/mmHg x 10 (range 4.5-28.6), and 12.6 ml/mmHg x 10 (range 5.2-20.1) immediately after phlebotomy (NS). The mean small artery compliance (C2) before and immediately after phlebotomy were 4.4 mg/mmHg x 10 (range 1.2-14.3) and 5.5 mg/mmHg x 10 (range 1.2-15.6) respectively (delta C2-1.1, P < 0.001). No difference in these parameters could be demonstrated in the long-term arm. CONCLUSIONS: Phlebotomy immediately improves arterial compliance in small vessels of PV patients, but this effect is short lived.

Aged↗

PubMed2005

Beveled needle technique is not associated with low "take" rates in Israeli smallpox revaccination campaign.

BACKGROUND: In its first large-scale smallpox vaccination campaign in the 20(th) century, Israel has experienced an exceptionally high rate of failure to achieve clinical take following vaccination. It was hypothesized that this failure rates might be attributed to the unique vaccination technique adopted in Israel, of using beveled needles rather than bifurcated needles. MATERIALS AND METHODS: We retrospectively identified two cohorts vaccinated in the defined dates during the Israeli revaccination campaign, in which beveled needles and bifurcated needles were used alternately, and studied the impact of different covariates on clinical vaccination outcome measures. RESULTS: Of 116 subjects that were vaccinated within the defined dates, 46 were vaccinated using bifurcated needles, and 70 by beveled needles. 'Take' rates in subjects vaccinated up to 20 years earlier was 77.5%, compared with 97.2% among those vaccinated in the more distant past (p = 0.001). In multivariate analyses, vaccination 'take' was independently associated with a shorter time from previous vaccination (p = 0.013), but not with gender, birth country, vaccinator or the vaccination technique used. CONCLUSIONS: The low take rates observed in the Israeli smallpox revaccination campaign could not be attributed to the unique local vaccination technique, and was most likely induced by a higher rate of residual immunity among vaccinees, compared with the US, as well as by the lower vaccine concentrations used in Israel. In countries and circumstances when bifurcated needles are not sufficiently available, the beveled needle technique may be considered an appropriate alternative.

Adult↗

PubMed2005

Serum anti-Mullerian hormone levels during controlled ovarian hyperstimulation in women with polycystic ovaries with and without hyperandrogenism.

BACKGROUND: Anti-Mullerian hormone (AMH) is expressed in pre- and small-antral follicles. High serum levels are found in women with polycystic ovaries (PCO), accordant with their increased content of small follicles. To evaluate the relationship between AMH, folliculogenesis and hyperandrogenism, we compared serum AMH levels between women with PCO with and without hyperandrogenism and normal controls during controlled ovarian hyperstimulation (COH). METHODS: Nineteen women with PCO and hyperandrogenism (group A), 10 women with PCO but no hyperandrogenism (group B) and 23 ovulatory women with normal ovarian morphology (group C, controls) underwent COH with the long protocol. Serum levels of AMH, estradiol, androstenedione and follicular tracking were determined before gonadotropins treatment (day 0) and every 2-4 days up to the day of HCG administration. RESULTS: AMH levels declined gradually throughout COH in the three groups, but remained higher in groups A and B compared with the controls. Significantly higher levels were found in group A compared with group B, despite comparable numbers of small follicles. Multiple regression analysis revealed that both the number of small follicles and serum androgens were correlated to AMH. CONCLUSIONS: Women with PCO have higher serum AMH levels during COH than controls. Hyperandrogenism is associated with an additional increase in AMH. It is conceivable that hyperandrogenism may reflect more severe disruption of folliculogenesis in women with PCO or may affect AMH secretion.

Adult↗

PubMed2005

Secular trends in age at menarche, smoking, and oral contraceptive use among Israeli girls.

INTRODUCTION: The improved nutrition and socioeconomic status of the population in industrialized countries has resulted in a decrease in the mean age at menarche. This trend raises the question of whether cigarette smoking and the use of oral contraceptives, health behaviors often adopted during adolescence, may also be starting at a younger age. Cigarette smoking and use of oral contraceptives are a public health concern because they pose an increased risk for development of chronic diseases, particularly in combination. This study was designed to identify secular trends in age at menarche, at first cigarette, and at first use of oral contraceptives among a large population-based sample of young Israeli women and to assess whether these trends are associated with sociodemographic factors. METHODS: A systematic, population-based survey used data obtained from female recruits to the Israel Defense Force from 1986 to 2000. During the study period, 11,392 questionnaires were collected from Jewish women aged 18 to 19 years. Participants were interviewed concerning geographic origin and level of education, father's geographic origin and level of education, current smoking status, use of oral contraceptives, and recalled age at first menstruation, first cigarette, and first use of oral contraceptives. RESULTS: Reported mean age (-/+ D) at menarche showed a monotonic trend of decreasing over time, from 13.41 (-/+ .30) years for women born before 1970 to 13.03 (-/+ 1.28) years for those born after 1978 (P < .001). Women born after 1978 were twice as likely to experience menarche by the age of 11 as those born prior to 1970 (odds ratio 2.0; 95% confidence interval, 1.41-2.82). Significant trends toward younger age at first use were observed for cigarettes and oral contraceptives. CONCLUSION: The trends of earlier age at menarche, first cigarette, and first use of oral contraceptives suggest health behaviors among young women that may herald increased chronic disease morbidity in the future. These trends indicate the need for further investigation and preventive measures aimed at this population.

Adolescent↗

PubMed2005

Prevalence of iron deficiency and anemia among strenuously trained adolescents.

PURPOSE: There is a lack of awareness among physicians, dieticians, and public health planners as to the prevalence of iron deficiency and anemia among adolescents undergoing strenuous physical training. The aim of this study was to estimate the prevalence of iron deficiency and anemia among male adolescents undergoing such activity. METHODS: We studied 292 male adolescents on the day of entry into a volunteer military unit. Hemoglobin (Hb), mean corpuscular volume, ferritin, iron, iron-transferrin saturation, and soluble transferrin receptor (TfR) were measured, and TfR-F index was calculated. RESULTS: The mean Hb level (+/-SD) in the study population was 14.7 +/- .9 g/dL (range, 10.8-16.8 g/dL), mean ferritin level was 50.6 +/- 32.6 ng/mL (range, 5.4-162.5 ng/mL), and mean iron level was 97.1 +/- 39.9 microg/dL (range, 24-267 microg/dL). The prevalence of anemia (Hb <14 g/dL) was 18.5%, and 3.4% had Hb concentrations less than 13 g/dL. Iron deficiency (ferritin <22 ng/mL) was present in 18% of the subjects, and 11.3% had ferritin levels less than 17 ng/mL. The mean soluble transferrin receptor concentration was 1.9 +/- .8 mg/L, and the mean TfR-F index was 1.21 +/- .57. CONCLUSIONS: Nearly 19% of the study subjects had mild anemia at recruitment, and depletion of iron stores was observed among 18%. Overall, these changes were not accompanied by a significant increase in soluble TfR. This high prevalence is most likely the result of "sports anemia" due to the intense physical training regimen adopted prior to their recruitment.

Adolescent↗

PubMed2005

Reliability of self-reported smoking history and age at initial tobacco use.

BACKGROUND: Many studies use questionnaires to determine smoking status and age of smoking onset. This study aimed to determine the reliability of self-reported smoking history and age of smoking initiation. METHOD: The proportion of inconsistent answers and correlation coefficients of reported age of initial smoking were measured by an answer-reanswer analysis of questionnaires in an ongoing, two-step, population-based survey of health behavior. Interviews were conducted on the day of recruitment to and the day of discharge from mandatory military service in Israel among a sample of 25,437 young men and women recruited between 1986 and 2000. RESULTS: Of 7276 participants reporting current or past smoking upon recruitment, 559 (7.7%) reported never having smoked upon discharge, thus demonstrating prima facie inconsistency. Variables significantly associated with reliable reporting in a multivariate logistic regression model were female gender (P = 0.04) and more than 4 years of military service (P < 0.01). 6010 subjects who reported a positive smoking history at both recruitment and discharge were available for analysis of reliability of reported age at smoking onset. Intraclass correlation coefficients for recruitment/discharge consistency in reported age at first cigarette were 0.73 (95% CI: 0.71-0.74) and 0.76 (95% CI: 0.74-0.78) for men and women, respectively. Eastern origin, lower subject education level, and lower paternal education level were also associated with lower reliability. CONCLUSIONS: Our results showed a relatively high level of answer-reanswer reliability, with some variance attributable to personal characteristics. These results suggest that self-reported age at onset of tobacco use is practical and reliable in normative, young adult populations. However, time elapsed between questionnaires and demographic and lifestyle characteristics may affect reliability rates, and thus should be carefully regarded in future studies.

Adolescent↗

PubMed2005

Influenza outbreak control in confined settings.

Influenza may rapidly disseminate within populations living in confined settings, causing considerable morbidity and disrupting daily activities. We describe an influenza A outbreak on a military base where 3,000 young adults, most of whom were unvaccinated, lived in close daily contact. Visits to the base clinic by 48 persons with acute respiratory illness within 2 days allowed early identification of this outbreak and prompted immediate epidemiologic investigation. Overall, 85 personnel (2.83% of base population) met the case definition for influenzalike illness. On-site laboratory confirmation with field detection kits, rapid implementation of respiratory illness control protocols, and a mass vaccination campaign were applied to limit disease dissemination. The outbreak was halted 14 days after the mass vaccination campaign was completed. We review the control measures available for controlling influenza outbreaks in confined settings and discuss the role of rapid mass vaccination within this context.

Disease Outbreaks↗

PubMed2005

Cost-benefit of stockpiling drugs for influenza pandemic.

We analyzed strategies for the use of stockpiled antiviral drugs in the context of a future influenza pandemic and estimated cost-benefit ratios. Current stockpiling of oseltamivir appears to be cost-saving to the economy under several treatment strategies, including therapeutic treatment of patients and postexposure prophylactic treatment of patients' close contacts.

Acetamides↗

PubMed2005

Infectious diarrheal outbreaks in the Israeli military, 1988-2002.

We analyzed 865 diarrheal outbreaks with an identified bacterial pathogen or unknown cause that occurred in the Israeli military between 1988 and 2002. The number of outbreaks per year declined over the study period, as did the proportion of outbreaks with an identified pathogen. Shigella, Salmonella, and Staphylococcus species were the bacteria most commonly isolated. Seventy percent of the outbreaks involved < 35 cases and only 5% involved > 100 cases. More than one-half of the outbreaks occurred in field units, but these outbreaks were smaller than those in other units. The most commonly identified cause of the outbreaks was a lapse in maintaining standards of food preparation. Improvements in infrastructure and enhanced attention to surveillance, education, and infection control have resulted in a marked decline in the number of outbreaks in recent years.

Disease Outbreaks↗

PubMed2005

[Smallpox vaccination techniques: considerations and unresolved issues].

The smallpox vaccine is the oldest--and was, for 90 years, the only--vaccine known to man. Many vaccination techniques have been used over time, with no fewer than ten employed during the 20th century alone. In Israel, two main techniques were used prior to smallpox eradication in 1978--multiple punctures using a standard needle, and jet injection--while most other countries adopted the bifurcated needle as the method of choice. Despite the vaccination experience gained over time, doubt remains today as to the preferred vaccination technique. During 2002, when Israel became the first country to conduct large-scale smallpox vaccination in the 21st century, multiple standard needle puncture was adopted as the method of choice, while at the same time the bifurcated needle was readopted in the United States. The article reviews the various smallpox vaccination techniques, the supporting scientific data, and the current lacunae in knowledge related to the subject. Together, these factors will most likely influence the adoption of a preferred vaccination technique during a smallpox emergency.

Humans↗