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Biomedical subjects

M Hurwitz

Publications and source records attributed to M Hurwitz.

At least 19 recordsLinked to original sources
PubMed2001

The clinical utility of the percent of positive prostate biopsies in predicting biochemical outcome following external-beam radiation therapy for patients with clinically localized prostate cancer.

PURPOSE: An investigation was performed of the clinical utility of the percent of positive prostate biopsies in predicting prostate-specific antigen (PSA) outcome following external-beam radiation therapy (RT) for men with PSA-detected or clinically palpable prostate cancer. METHODS AND MATERIALS: A Cox regression multivariable analysis was used to determine whether the percent of positive prostate biopsies provided clinically relevant information about PSA outcome following external beam RT in 473 men while accounting for the previously established risk groups based on the pretreatment PSA level, biopsy Gleason score, and the 1992 American Joint Commission on Cancer (AJCC) clinical T stage. RESULTS: Controlling for the known prognostic factors, the percent of positive prostate biopsies added clinically significant information (p = 0.02) regarding time to PSA failure following RT. Specifically, 76% of the patients in the intermediate risk group (1992 AJCC T(2b) or biopsy Gleason 7 or PSA > 10 ng/mL and < or = 20 ng/mL) could be classified into either an 30% or 85% 5-year PSA control cohort using the preoperative prostate biopsy data. CONCLUSION: The previously validated stratification of PSA outcome following radical prostatectomy (RP) using the percent of positive prostate biopsies in intermediate-risk patients is also clinically significant for men treated with external beam RT. The percent positive prostate biopsies should be considered in conjunction with the PSA level, biopsy Gleason score, and 1992 AJCC clinical T stage when counseling patients with newly diagnosed and clinically localized prostate cancer about PSA outcome following RP or external beam RT.

Biopsy↗
PubMed2001

The relationship between low level nitrogen dioxide exposure and child lung function after cold air challenge.

BACKGROUND: Nitrogen dioxide (NO(2)) or home gas appliance use has been inconsistently associated with adverse respiratory outcomes in childhood. OBJECTIVES: (i) To examine the contribution of home gas appliance type and personal NO(2) exposure. (ii) To examine the relationship between NO(2) exposure and child lung function and respiratory history. (iii) To assess whether these relationships vary by house dust mite sensitization status. METHODS: A cross-sectional survey of 344 children (71% of the eligible group) with a mean age of 9.1 years from four randomly selected schools in the Australian Capital Territory from July to September 1999. Study measurements included a parental questionnaire, NO(2) exposure by passive gas samplers, skin prick testing for 10 aeroallergens and lung function at rest and after cold air challenge. RESULTS: Total NO(2) exposure was low with a mean concentration of 10.1 ppb. No associations were found between NO(2) exposure or gas appliance use and asthma, wheeze or baseline lung function. Personal NO(2) exposure was associated with a reduction in forced expiratory volume in one second (FEV1)/forced vital capacity (FVC) after cold air challenge (adjusted difference - 0.12% (- 0.23% to - 0.01%) per 1 ppb increase). After exclusion of children who had home heating changed because of asthma, gas heater use was also significantly associated with a reduction in this measure (adjusted difference - 2.0% (- 3.7% to - 0.2%)). There was some evidence that these reductions were greater among the non-mite-sensitized children. CONCLUSIONS: The effect of low-level NO(2) exposure on these respiratory outcomes was not marked. The possible effect of low-level NO(2) exposure on non-specific bronchial reactivity requires confirmation. Future studies on NO(2) and respiratory health should include measures of house dust mite sensitization and bronchial hyper-responsiveness.

Air↗
PubMed2001

Tuberculosis notifications in Australia, 1998.

Since the inception of the National Mycobacterial Surveillance System (NMSS) in 1991, annual crude notification rates for tuberculosis have remained stable at between 5 and 6 per 100,000 population. In 1998, there was a total of 923 TB notifications in Australia of which 884 were new TB cases, and 39 relapsed cases. The corresponding annual crude notification rate for new and relapsed TB was 4.72 and 0.21 per 100,000 respectively. Seventy-seven percent of notifications that had a country of birth reported were overseas born. In keeping with trends observed over recent reporting years, the populations for which notified TB rates are highest include the overseas born from high prevalence countries and Indigenous Australians. The lowest rates of disease have continued to be reported in the non-Indigenous, Australian born population. Surveillance reports over the last seven years indicate that the rate of disease in this population is gradually declining.

Adolescent↗
PubMed2000

Utilizing predictions of early prostate-specific antigen failure to optimize patient selection for adjuvant systemic therapy trials.

PURPOSE: Prostate-specific antigen (PSA) failure within 2 years after radical prostatectomy (RP) has been shown to be a clinically significant predictor of distant failure. This study was performed to estimate 2-year PSA failure rates on the basis of readily available clinical and pathologic factors to identify patients for whom effective adjuvant systemic therapy is needed. PATIENTS AND METHODS: A Cox regression multivariable analysis was used to determine whether the percentage of positive prostate biopsies, PSA level, and the pathologic findings at RP in 1,728 men provided clinically relevant information about PSA outcome after RP. A bootstrapping technique with 2,000 replications was used to provide 95% confidence intervals for the predicted 2-year PSA failure rates, which were determined on the basis of the independent clinical and pathologic predictors of PSA outcome. RESULTS: The independent predictors of time to PSA failure included a percentage of positive prostate biopsies of greater than 34% (P: < or =.009), PSA level greater than 10 ng/mL (P: < or =.01), seminal vesicle invasion (P: =. 02), prostatectomy Gleason score of 8 to 10 (P: =.04), and positive surgical margins (P: =.0001). Predictions of 2-year PSA failure rates and bootstrap estimates of the 95% confidence intervals were arranged in a tabular format, stratified by independent clinical and pathologic predictors of PSA outcome. CONCLUSION: Patients who are most likely to benefit from effective adjuvant systemic therapy after RP can be identified using readily available clinical and pathologic data.

Biopsy↗
PubMed2000

Biochemical outcome following external beam radiation therapy with or without androgen suppression therapy for clinically localized prostate cancer.

CONTEXT: Combined treatment using radiation therapy (RT) and androgen suppression therapy (AST) is used to treat men with clinically localized adenocarcinoma of the prostate, but outcome using this combined therapy compared with RT alone is not known. OBJECTIVE: To determine the relative efficacy of RT plus AST vs RT alone among men with clinically localized prostate cancer. DESIGN, SETTING, AND PATIENTS: Retrospective cohort study of 1586 men with prostate cancer who were treated between January 1989 and August 1999 using 3-dimensional conformal RT with (n = 276) or without (n = 1310) 6 months of AST. MAIN OUTCOME MEASURE: Relative risk (RR) of prostate-specific antigen (PSA) failure (defined according to the American Society for Therapeutic Radiology and Oncology consensus statement), by treatment and high-, intermediate-, or low-risk group based on serum PSA level, biopsy Gleason score, and 1992 American Joint Commission on Cancer clinical tumor category. RESULTS: Estimates of 5-year PSA outcome after RT with or without AST were not statistically different among low-risk patients (P =.09), whereas intermediate- and high-risk patients treated with RT plus AST had significantly better outcomes than those treated with RT alone (P<.001 and =.009, respectively). The RR of PSA failure in low-risk patients treated with RT plus AST was 0.5 (95% confidence interval [CI], 0.3-1.1) compared with patients treated with RT alone. The RRs of PSA failure in intermediate-risk and high-risk patients treated with RT plus AST compared with RT alone were 0.2 (95% CI, 0. 1-0.3) and 0.4 (95% CI, 0.2-0.8), respectively. CONCLUSIONS: Our data suggest a significant benefit in 5-year PSA outcomes for men with clinically localized prostate cancer in intermediate- and high-risk groups treated with RT plus AST vs those treated with RT alone. Results from prospective randomized trials currently under way are needed to validate these findings. JAMA. 2000;284:1280-1283

Adenocarcinoma↗
PubMed2000

Long-term effects of asthma education for physicians on patient satisfaction and use of health services.

This randomized clinical trial evaluated the long-term impact of an interactive seminar for physicians based on principles of self-regulation on clinician behaviour, children's use of health services for asthma, and parent's views of physician performance. Seventy-four general practice paediatricians, and 637 of their asthma patients aged 1-12 yrs, were randomized to treatment or control. Children and parents were blind to physicians' participation. Data were collected at baseline and follow-up through self-administered surveys (paediatricians), telephone interviews (parents) and medical records. The seminar focused on development of communication and teaching skills and use of therapeutic medical regimens for asthma as outlined in the National Asthma Education and Prevention Program guidelines. Approximately 2 yrs postintervention, treatment group physicians were more likely than control physicians to: use protocols for delivering asthma education (odds ratio (OR) 4.9, p=0.2), write down for patients how to adjust medicines when symptoms change (OR 5.7, p=0.05), and provide more guidelines for modifying therapy (OR 3.8, p=0.06). Parents scored treatment group physicians higher than control physicians on five specific positive communication behaviours. Children seen by treatment group physicians had fewer hospitalizations (p=0.03) and those with higher levels of emergency department (ED) use at baseline had fewer subsequent ED visits (p=0.03). No differences regarding the number of office visits were noted. There were no significant differences found between treatment and control group physicians in the amount of time spent with patients during office visits (26 versus 29 min) or in the number of patients treated with anti-inflammatory medicine. It is concluded that interactive asthma seminars for paediatricians had significant long-term benefits for their asthma care.

Adult↗
PubMed2000

Evaluation of the use of botulinum toxin in children with achalasia.

BACKGROUND: Achalasia is rare in children. Recently, injection of botulinum toxin into the lower esophageal sphincter has been studied as an alternative to esophageal pneumatic dilatation or surgical myotomy as treatment for achalasia. In the current study, the effects of botulinum toxin were investigated in the largest known series of children with achalasia. METHODS: Treatment for achalasia was assessed in 23 pediatric patients who received botulinum toxin from June 1995 through November 1998. Those who continued to receive botulinum toxin and did not subsequently undergo pneumatic dilatation or surgery were considered repeat responders. Results were compared with those of published studies evaluating the use of botulinum toxin in adults with achalasia. RESULTS: Nineteen patients initially responded to botulinum toxin. Mean duration of effect was 4.2 months +/- 4.0 (SD). At the end of the study period, three were repeat responders, three experienced dysphagia but did not receive pneumatic dilatation or surgery, three underwent pneumatic dilatation, eight underwent surgery, three underwent pneumatic dilatation with subsequent surgery, and three awaited surgery. Meta-analysis shows that, in the current study group, the data point expressing time of follow-up evaluation versus percentage of patients needing one injection session without additional procedures (botulinum toxin injection, pneumatic dilatation, or surgery) falls within the curve for those in studies on adult patients receiving botulinum toxin for achalasia. CONCLUSIONS: Botulinum toxin effectively initiates the resolution of symptoms associated with achalasia in children. However, one half of patients are expected to need an additional procedure approximately 7 months after one injection session. The authors recommend that botulinum toxin be used only for children with achalasia who are poor candidates for either pneumatic dilatation or surgery.

Adolescent↗
PubMed2000

Comparing prostate specific antigen outcomes after different types of radiotherapy management of clinically localized prostate cancer highlights the importance of controlling for established prognostic factors.

PURPOSE: We evaluated the impact that the composition of prognostic factors in a patient cohort may have on prostate specific antigen (PSA) outcome following external beam radiation therapy for clinically localized prostate cancer. MATERIALS AND METHODS: The distribution of PSA, biopsy Gleason score and American Joint Committee on Cancer (AJCC) T stage in men with prostate cancer treated with interstitial plus external beam radiation therapy was used to select a matched cohort who underwent 3-dimensional (D) conformal external beam radiation therapy. We compared PSA outcomes after 3-D conformal external beam radiation therapy in the overall and matched cohorts of 766 and 570 patients, respectively. RESULTS: Men treated with interstitial plus external beam radiation therapy had a significantly lower rate of PSA greater than 10 to 20 (p = 0. 02) and greater than 20 ng./ml. (p <0.0001), biopsy Gleason score 7 (p = 0.02) and 8 to 10 (p <0.0001), and AJCC stage T2c disease (p <0. 0001). Likewise, these men also had a significantly higher rate of PSA greater than 4 to 10 ng./ml. (p <0.0001), biopsy Gleason score 5 to 6 (p = 0.0001) and AJCC stage T1 disease (p <0.0001) than those who underwent 3-D conformal external beam radiation therapy. The 5-year estimate of PSA failure-free survival after 3-D conformal external beam radiation therapy was 45% versus 67% (p = 0.0007) for all 766 consecutively treated patients and the matched cohort of 570, respectively. CONCLUSIONS: The composition of prognostic factors in a patient cohort may impact PSA outcome. Therefore, controlling for established prognostic factors is essential when comparing PSA outcome after different forms of radiotherapy for adenocarcinoma of the prostate.

Adenocarcinoma↗
PubMed2000

Clinical utility of percent-positive prostate biopsies in predicting biochemical outcome after radical prostatectomy or external-beam radiation therapy for patients with clinically localized prostate cancer.

BACKGROUND AND PURPOSE: The clinical utility of the percentage of positive prostate biopsies in predicting prostate specific antigen (PSA) outcome after radical prostatectomy (RP) or external-beam radiation therapy (EBRT) for men with PSA-detected or palpable prostate cancer is not established. METHODS: A Cox regression multivariable analysis was used to determine whether percent-positive prostate biopsies provided clinically relevant information about PSA outcome after RP in 960 men, while accounting for the previously established risk groups based on the pretreatment PSA concentration biopsy Gleason score, and the 1992 American Joint Commission on Cancer clinical T stage. RESULTS: In the intermediate-risk group, 80% of the patients (stage T(2b) or biopsy Gleason 7 or PSA 10-20 ng/mL) could be classified into either an 11% or an 86% 4-year PSA control cohort using the preoperative prostate biopsy data. These findings were validated using an independent surgical (N = 823) and radiation (N = 473) data set. Percent-positive prostate biopsies added clinically significant information regarding time to PSA failure after RP. CONCLUSIONS: The percentage of positive prostate biopsies should be considered in conjunction with the PSA level, biopsy Gleason score, and clinical T stage when counseling patients with newly diagnosed and clinically localized prostate cancer about PSA outcome after RP or EBRT.

Biopsy↗
PubMed1999

Laparoscopic management of benign solid and cystic lesions of the liver.

OBJECTIVE: The authors present their experience in the laparoscopic management of benign liver disease. The aim of the study is to analyze technical feasibility and evaluate immediate and long-term outcome. SUMMARY BACKGROUND DATA: Indications for the laparoscopic management of varied abdominal conditions have evolved. Although the minimally invasive treatment of liver cysts has been reported, the laparoscopic approach to other liver lesions remains undefined. METHODS: Between September 1990 and October 1997, 43 patients underwent laparoscopic liver surgery. There were two groups of benign lesions: cysts (n = 31) and solid tumors (n = 12). Indications were solitary giant liver cysts (n = 16), polycystic liver disease (n = 9), hydatid cyst (n = 6), focal nodular hyperplasia (n = 3), and adenoma (n = 9). Only solid tumors, hydatid cysts, and patients with polycystic disease and large dominant cysts located in anterior liver segments were included. All giant solitary liver cysts were considered for laparoscopy. Patients with cholangitis, cirrhosis, and significant cardiac disease were excluded. Data were collected prospectively. RESULTS: The procedures were completed laparoscopically in 40 patients. Median size was 4 cm for solid nodules and 14 cm for solitary liver cysts. Conversion occurred in three patients (7%), for bleeding (n = 2) and impingement of a solid tumor on the inferior vena cava (n = 1). The median operative time was 179 minutes. All solitary liver cysts were fenestrated in less than 1 hour. There were no deaths. Complications occurred in 6 cases (14.1%). Two hemorrhagic and two infectious complications were noted after management of hydatid cysts. There were no complications after resection of solid tumors. Three patients received transfusions (7%). The median length of stay was 4.7 days. Median follow-up was 30 months. There was no recurrence of solitary liver or hydatid cysts. One patient with polycystic disease had symptomatic recurrent cysts at 6 months requiring laparotomy. CONCLUSION: Laparoscopic liver surgery can be accomplished safely in selected patients with small benign solid tumors located in the anterior liver segments and giant solitary cysts. The laparoscopic management of polycystic liver disease should be reserved for patients with a limited number of large, anteriorly located cysts. Hydatid disease is best treated through an open approach.

Adult↗
PubMed1999

Increased pertechnegas lung clearance in interstitial lung disease.

BACKGROUND: Interstitial lung disease (ILD) is characterized by inflammation within the alveolar walls and interstitium of the lungs. This causes increased alveolar-capillary membrane permeability. The diagnosis is made by clinical features, chest roentgenography, lung function tests, and high-resolution CT, and it is confirmed by lung biopsy. Radionuclide aerosol tracers such as Tc-99m DTPA show increased lung clearance in ILD. The clearance rate of microaerosol pertechnegas (modified Technegas) from the lungs in the assessment of ILD was evaluated. METHODS: Thirty-two patients (22 with ILD and 10 with non-ILD) were evaluated with pertechnegas. Pertechnegas is formed by adding 3% oxygen to technegas, a microaerosol ventilation agent. Regions of interest were then drawn around the lungs, and clearance rates were determined from the best exponential fit. RESULTS: The mean clearance rate of pertechnegas was significantly increased in ILD and measured 5.78 +/- 2.2 minutes compared with non-ILD, which measured 8.53 +/- 2.42 minutes (P < 0.001). The sensitivity and specificity rates of pertechnegas clearance (less than 8 minutes) in ILD were 90% and 60%, respectively. When combined with chest roentgenography, the sensitivity and specificity rates increased to 100% and 90%, respectively. CONCLUSIONS: Pertechnegas is highly effective in determining the presence of active ILD. It differentiates between active ILD and non-ILD, and it is highly sensitive and specific when combined with chest roentgenography. Its potential role in the management of ILD merits further investigation.

Adult↗
PubMed1998

Impact of education for physicians on patient outcomes.

OBJECTIVES: This study was conducted to assess the impact of an interactive seminar based on self-regulation theory on 1) the treatment practices and communications and education behavior of physicians, 2) the health status and medical care utilization of their pediatric patients with asthma, and 3) the satisfaction with care of the subjects' parents. METHODS: A total of 74 general practice pediatricians were assigned to either a program or a control group in a randomized controlled study. Data were collected from physicians at baseline, and 69 (93%) provided follow-up data 5 months after the program. Data were also collected from 637 of their patients at baseline, and in a 22-month window after the intervention, 472 (74%) of this number provided follow-up data. RESULTS: After the seminar, physicians in the program group were more likely than were control group physicians to address patients' fears about medicines, review written instructions, provide a sequence of educational messages, write down how to adjust the medicines at home when symptoms change, and report that they spent less time with their patients. Parents of the children treated by program physicians were significantly more likely than were control group parents to report that the physician had been reassuring, described as a goal that the child be fully active, and gave information to relieve specific worries. After a visit with the physician, these parents were also more likely to report that they knew how to make management decisions at home. After the intervention compared to controls, patients of physicians in the program group were more likely to have received a prescription for inhaled antiinflammatory medicine and to have been asked by the physician to demonstrate how to use a metered-dose inhaler. After the intervention, children seen by program physicians made significantly fewer nonemergency office visits and visits for follow-up of an episode of symptoms; however, there were no differences in emergency department visits and hospitalizations. Among children who were placed on inhaled corticosteroids during this study, however, children treated by physicians who had received education had significantly fewer symptoms and fewer follow-up office visits, nonemergency physician office visits, emergency department visits, and hospitalizations. CONCLUSIONS: The interactive seminar based on theories of self-regulation led to patient-physician encounters that were of shorter duration, had significant impact on the prescribing and communications behavior of physicians, led to more favorable patient responses to physicians' actions, and led to reductions in health care utilization.

Asthma↗
PubMed1998

Managing care in an integrated delivery system via an Intranet.

The CareGroup Provider Service Network is a managed care contracting organization which provides central administrative services for over 1800 physicians and 200,000 managed care lives. Services include utilization management, disease management and credentialing for the entire network. The management model of the Provider Service Network empowers local physician groups with information and education. To meet the managed care information needs of the network, we implemented an intranet-based executive information system, PSNWeb, which retrieves data from a managed care data warehouse. The project required the integration of diverse technologies and development of a complex security/confidentiality infrastructure to deliver information to 8 major clinician groups, each with different information needs.

Computer Security↗
PubMed1997

Pancreatic endocrine tumors with loss of heterozygosity at the multiple endocrine neoplasia type I locus.

BACKGROUND: Loss of heterozygosity (LOH) at chromosome 11q13 has been demonstrated in multiple endocrine neoplasia type I (MEN I) and sporadic parathyroid tumors, pituitary adenomas, and a few types of pancreatic endocrine tumors. Gastrinomas are the most common pancreatic endocrine tumor in MEN I. We hypothesized that all pancreatic endocrine tumors have LOH at 11q13, resulting in inactivation of the previously described tumor suppressor gene in this region. METHODS: We analyzed a sporadic gastrinoma, a MEN I-associated gastrinoma, and a nonfunctional pancreatic endocrine tumor from a patient with Von Hippel-Lindau (VHL) disease for LOH at seven loci at 11q13: D11S149, PYGM, D11S427, D11S546, SEA, D11S97, and D11S146. RESULTS AND CONCLUSIONS: We found LOH at 11q13 in all three tumors. The MEN I-associated gastrinoma we analyzed is the first tumor of this type to have LOH. This is also the first report of LOH at 11q13 in a pancreatic endocrine tumor from a patient with VHL. These findings suggest that the etiology of pancreatic endocrine tumor formation involves a common genetic pathway for sporadic, MEN I, and VHL tumors.

Chromosome Deletion↗
PubMed1997

Toxocara canis infection and granulomatous hepatitis.

This report describes possible involvement of Toxocara canis in granulomatous hepatitis in three patients who presented with varied clinical features; two were being treated for other diagnoses until Toxocara serology became available. Despite initial nonspecific therapy, there was clinical improvement in all patients and complete resolution of symptoms and abnormal liver biochemistry in two. T. canis infection should be considered in cases of granulomatous hepatitis.

Adult↗
PubMed1996

Elevation of cGMP with normal expression and activity of rod cGMP-PDE in photoreceptor degenerate labrador retrievers.

Cyclic guanosine 3',5'-monophosphate (cGMP) levels were determined in retinas from a strain of Labrador Retrievers with inherited retinal dystrophy manifesting at early stages of retinal differentiation. The cGMP contents of dystrophic retinas of dogs from 1 to 4 months of age (n = 7) were significantly higher (p = 0.001) than in age-matched controls of the same breed (n = 11). Ultrastructure along the vertical retinal meridian was studied in developing retinas and findings were related to those of age-matched wild-type controls of the same breed. Slow central to peripheral progression of degeneration was observed in affected dogs. No differences were found in total cGMP-phosphodiesterase (PDE) activity, in PDE subunit composition as determined by Western blotting of 2-month-old homozygote affected retinas, or in the amino acid sequence deduced from the nucleotide sequence of the PDE beta-subunit as compared to controls. This model of photoreceptor degeneration thus is the first case of an apparent abnormality of cGMP metabolism that is not associated with a defect in the PDE catalytic subunits, and it is also the first reported model not associated with severe developmental abnormalities and rapid degeneration.

3',5'-Cyclic-GMP Phosphodiesterases↗
PubMed1994

Putative tumor-suppressor gene on chromosome 11 is important in sporadic endocrine tumor formation.

Endocrine tumors arising sporadically or as a manifestation of the multiple endocrine neoplasia type I syndrome (MEN I) have been shown to have mutations on chromosome 11. These mutations can be detected at the molecular level by loss of heterozygosity (LOH) for DNA markers from chromosome 11. This study represents one of the largest collections of sporadic endocrine tumors in which LOH was systematically assessed on chromosome 11 for the loci flanking the proposed MEN I region. DNA was isolated from 39 endocrine tumors and probed with 7 DNA probes spanning the region of chromosome 11q13 from the loci PYGM to INT-2. Eleven tumors demonstrated LOH at any two loci in this region. The remaining 28 tumors showed no LOH or were noninformative at these loci. Thus, nearly 30% of these tumors showed LOH in the region (from PYGM to INT-2) that is thought to contain the MEN I gene(s). Previous studies of sporadic endocrine tumors have suggested that these tumors may arise via the same mechanism as tumors of the MEN I syndrome. Namely, these sporadic tumors are thought to result from mutations leading to genetic loss on the long arm of chromosome 11, thereby inactivating a possible tumor-suppressor gene (or genes). These findings strongly support the hypothesis that sporadic pancreatic endocrine tumors share a similar etiology of tumorigenesis with tumors of the MEN I syndrome, which principally involves deletion of a tumor-suppressor element (or elements).

Blotting, Southern↗