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Biomedical subjects

A Rosenbaum

Publications and source records attributed to A Rosenbaum.

At least 19 recordsLinked to original sources

Levels of analysis for the study of environmental health disparities.

Reducing racial/ethnic and socioeconomic environmental health disparities requires a comprehensive multilevel conceptual and quantitative approach that recognizes the various levels through which environmental health disparities are produced and perpetuated. We propose a conceptual framework that incorporates the micro level, contained within the local level, which in turn is contained within the macro level. We discuss the utility of multilevel techniques to examine environmental level (both physical and social) and individual-level factors to appropriately quantify and improve our understanding of environmental health disparities. We discuss the reasoning and the methodological approach behind multilevel modeling, including differentiating between individual and contextual influences on individual outcomes. Next we address the questions and principles that guide the choice of levels or geographic units in multilevel studies. Finally, we address the ways in which different data sources can be combined to produce suitable data for multilevel analyses. We provide some examples of how such data sources can be linked to create multilevel data structures, and offer suggestions to facilitate the integration of multilevel techniques in environmental health disparities research and monitoring.

Environmental Exposure↗

Slaughterhouse survey of pyelonephritis in dairy cows.

Twenty-one rejected kidneys from 2426 slaughtered dairy cows (0.87 per cent) had gross signs of pyelonephritis that were confirmed by histopathology. In all the kidneys the findings were consistent with a chronic rather than an acute infection. One species of bacteria was cultured from 12 of the kidneys and two species of bacteria were cultured from six. The most commonly isolated bacteria were Escherichia coli, from eight kidneys, Arcanobacterium pyogenes, from seven kidneys and Corynebacterium renale, from five kidneys. The other bacteria cultured were Corynebacterium cystitidis, Corynebacterium species, Streptococcus species group G and Enterococcus faecalis. E. coli was cultured from all the kidneys from which two species were isolated; the accompanying bacteria were A. pyogenes in three kidneys, C. renale in two and C. cystitidis in one. No bacteria were cultured from two of the kidneys and no significant bacteria were cultured from another. The kidneys with pyelonephritis were slightly larger than a comparison group of 72 kidneys without nephritis.

Abattoirs↗

[Photodynamic therapy of dysplasias and early carcinomas in Barrett esophagus with a diode laser system--a pilot study].

BACKGROUND: Photodynamic therapy (PDT) of dysplasia and early cancer of the esophagus could show good results in the potential of ablation. Unfortunately, the existing expensive and temperamental dye laser systems foiled a broad clinical use. In this pilot study, we investigated the feasibility of an inexpensive and maintenance-free diode laser system for PDT of dysplasia and early cancer in Barrett's esophagus. PATIENTS AND METHODS: Eight patients with Barrett's esophagus and/or early cancer were treated. As light source we used a diode laser system with a maximum power output of 2 W and a wavelength of 633 +/- 3 nm. One patient was treated initially with Photosan-3, seven patients received 5-aminolevulinic acid. RESULTS: In all patients we could achieve reduction in length and/or histologically proven downgrading. In three quarters of the patients, complete eradication of adenocarcinoma could be attained. Columnar-lined metaplastic epithelium could also be completely eradicated. CONCLUSION: PDT using a diode laser system is comparably effective in Barrett's esophagus/early cancer as PDT with dye laser systems. PDT is a gentle and effective technique with little side effects.

Adenocarcinoma↗

Intravenous midazolam significantly enhances the lethal effect of thiopental but not that of ketamine in mice.

Intravenous (i.v.) drug combinations are used in clinical anaesthesia in order to combine the desired effects and minimize toxicity from large doses of single agents. This fundamental assumption has not been systematically evaluated. We examined its validity by testing the influence of midazolam on the lethal effect of i.v. thiopental and ketamine in mice. Dose-response curves were constructed for the lethal effect of i.v. thiopental and ketamine, and for the loss of righting reflex effect by midazolam, in sexually mature male ICR mice weighing 20-40 g. For each curve, six or seven groups of eight to 10 mice each were used. A quarter of the median effective dose (ED50) for loss of righting reflex by midazolam was combined with the two other drugs to deduce dose-response curves for the lethal effect of the combinations. The ED50 for loss of righting reflex by i.v. midazolam was 43.5 mg x kg(-1) (95% confidence interval [CI], 40.4-46.5). The median lethal dose (LD 50) of i.v. thiopental was 50.6 mg x kg(-1) (95% CI, 50.0-54.9) and that of ketamine 42.9 mg x kg(-1) (95% CI, 32.3-52). In the presence of 10 mg x kg(-1) midazolam, the LD50 of thiopental was reduced to 20 mg x kg(-1) (17.7-22.2), but that of ketamine remained 44.4 mg x kg(-1) (37.7-54.9). Midazolam increased the lethal effect of thiopental 2.5-fold, but did not affect that of ketamine. Interactions at the toxic level between commonly used anaesthetic agents may differ from those at the hypnotic or analgesic levels, which should prompt evaluation of such combinations before their introduction to routine clinical use.

Anesthetics, Dissociative↗

Photodynamic therapy with 5-aminolevulinic acid is not effective in bile duct cancer.

BACKGROUND: The results of preliminary studies of photodynamic therapy (PDT) for palliation of patients with bile duct cancer with hematoporphyrin derivative have been good. Rapid elimination of a photosensitizer could potentially shorten the time requirement for shielding from light. This would enhance the benefit of this form of palliative treatment. Therefore the feasibility of PDT was investigated for nonresectable bile duct cancer by using 5-aminolevulinic acid. METHODS: Four patients with nonresectable bile duct cancer underwent cholangiography, cholangioscopy, and intraductal US before PDT. Light activation was performed 5 to 7 hours after oral administration of 5-aminolevulinic acid. All patients had an endoprosthesis placed in the bile duct after PDT. RESULTS: Cholangioscopy 72 hours after PDT revealed superficial fibrinoid necrosis. However, 4 weeks after PDT there was no significant reduction in bile duct stenoses. Two patients had infectious complications develop, but phototoxicity was not observed. CONCLUSIONS: Although superficial tumor necrosis was evident, PDT with 5-aminolevulinic acid failed to significantly reduce malignant bile duct obstruction. Therefore 5-aminolevulinic acid-PDT cannot be recommended for the palliative treatment of bile duct cancer.

Administration, Oral↗

Photodynamic therapy for palliation of nonresectable bile duct cancer--preliminary results with a new diode laser system.

OBJECTIVES: Preliminary results of photodynamic therapy (PDT) of bile duct cancer have shown astonishingly good results in the reduction of cholestasis, improvement of quality of life, and even prolongation of the survival time. Unfortunately, the existing dye laser systems are large and costly, and their maintenance is expensive. Therefore, we investigated the feasibility of a diode laser system for PDT of nonresectable bile duct cancer. METHODS: Eight patients with nonresectable bile duct cancer were treated. Forty-eight hours after i. v. application of 2 mg/kg body weight of Photosan-3, light activation was performed by a transpapillary (four patients) or percutaneus (four patients) access. We used a cylindrical diffusor tip and illuminated using a wavelength of 633+/-3 nm and a total energy of 200 J/cm2. All patients were additionally provided with bile duct endoprostheses after PDT. RESULTS: Four weeks after initial PDT all patients showed a marked reduction of bile duct stenosis. The median serum bilirubin value declined from 5.8 mg/dl (2.0-10.1) to 1.0 mg/dl (0.8-4.4). The median survival time at the time of writing is 119 days (52-443). Five patients are still alive. In four patients we could change from percutaneous to transpapillary drainage after PDT, two patients showed infectious complications. CONCLUSION: PDT with the diode laser system seems to be effective in reducing malignant bile duct stenosis. This treatment is minimally invasive and has a low specific complication rate. Randomized, controlled studies comparing PDT with the insertion of endoprostheses and long term follow-up of results are needed to confirm the promising short term results.

Aged↗

[Prevention of colorectal carcinoma. Annual hemoccult test and sigmoidoscopy every 5 years].

The slow development of colorectal carcinoma from adenoma over dysplastic state to malignancy within 10-15 years results in a long preclinical phase during which the tumor is readily detectable and curable. Therefore and because of the lack of early alerting signs colorectal cancer is highly suited to screening. The faecal occult blood test has been added to the yearly program of cancer prevention for each individual age 45 and higher. This test has been evaluated in controlled prospective trials. For several reasons the combination of faecal occult blood test with flexible sigmoidoscopy at five year intervals is recommended. Concerning colonoscopy as a screening test to date no data from controlled trails are available. Virtual colonoscopy and gene-based screening which are currently being developed may be future options.

Aged↗

The role of Doppler ultrasound in gastrointestinal bleeding.

The management of acute gastrointestinal bleeding is the domain of endoscopy. More than half of all episodes of upper gastrointestinal bleeding are attributed to bleeding peptic ulcers, and it is important to assess the risk of recurrent bleeding and to determine the appropriate treatment. However, the visual assessment of lesions (Forrest classification) is not always accurate and shows high interobserver variability (especially for visible vessels at the ulcer base, associated with a high rate of re-bleeding). Doppler ultrasound was thus introduced, and several studies have demonstrated that, with Doppler examination, these vessels can be identified. Doppler ultrasound is also used to monitor the effects of endoscopic therapy. In a prospective randomized trial, Doppler ultrasound proved superior to the Forrest classification. Treatment based on this technique resulted in significantly lower rates of re-bleeding and mortality. The Doppler classification may be able to contribute to a safer and more cost-effective management of patients with acute peptic ulcer bleeding.

Blood Flow Velocity↗

Pseudotumor of the sigmoid mimicking carcinoma.

On colonoscopy, the macroscopic aspect of a lesion is an important criterion for the differential diagnosis. We present a case of an apparently malignant tumor in the sigmoid. Histological investigation failed to support the diagnosis made from the gross appearance seen on colonoscopy. After surgical resection, the lesion turned out to be a reactive pseudotumor caused by fibroepithelial hyperplasia related to a severe diverticulitis with perforation of the intestinal wall.

Aged↗

Virtual endoscopic environments in modern neurosurgical practice.

Modern radiographic techniques have allowed the creation of high-definition planar images that can provide important anatomical as well as physiological data. Planar imaging sets can be reformatted into three-dimensional (3-D) data sets that can then be manipulated to demonstrate important anatomical or gross pathological features. Three-dimensional data sets have been used with success in modern image-guided or frameless stereotactic surgery. Another potential application is so-called "virtual endoscopy" or "scopeless endoscopy," in which a 3-D anatomical data set is reformatted into a volume-rendered image that can then be viewed. By reformatting images in this way, a "surgeon's-eye" view can be obtained, which can aid in presurgical planning and diagnosis. The use of virtual endoscopy has the potential to increase our understanding of the appropriate anatomy and the anatomical relationships most apparent during neurosurgical approaches. In so doing, virtual endoscopy may serve as an important means of planning for therapeutic interventions. On the other hand, one must always be cognizant of the technical limitations of these studies regardless of the quality of the reconstructed images. Prospective, correlative, clinical studies in which the anatomical advantages of virtual-based endoscopy are evaluated in large cadaver or patient series must be performed. Until then, the only potential ways to compensate for errors that exist in the algorithms and reconstructions of 3-D endoscopic images are based on the surgeon's understanding of the clinical state of the patient and prior experience with the anatomy in the region of question.

Journal Article↗

Familial encephalopathy with neuroserpin inclusion bodies.

We report on a new familial neurodegenerative disease with associated dementia that has presented clinically in the fifth decade, in both genders, and in each of several generations of a large family from New York State-a pattern of inheritance consistent with an autosomal dominant mode of transmission. A key pathological finding is the presence of neuronal inclusion bodies distributed throughout the gray matter of the cerebral cortex and in certain subcortical nuclei. These inclusions are distinct from any described previously and henceforth are identified as Collins bodies. The Collins bodies can be isolated by simple biochemical procedures and have a surprisingly simple composition; neuroserpin (a serine protease inhibitor) is their predominant component. An affinity-purified antibody against neuroserpin specifically labels the Collins bodies, confirming their chemical composition. Therefore, we propose a new disease entity-familial encephalopathy with neuroserpin inclusion bodies (FENIB). The conclusion that FENIB is a previously unrecognized neurodegenerative disease is supported by finding Collins bodies in a small kindred from Oregon with familial dementia who are unrelated to the New York family. The autosomal dominant inheritance strongly suggests that FENIB is caused by mutations in the neuroserpin gene, resulting in intracellular accumulation of the mutant protein.

Amino Acid Sequence↗

Neuropsychological correlates of domestic violence.

Neuropsychological functioning was assessed in 39 males who had committed domestic violence (batterers) and compared to 63 nonviolent (both maritally discordant and satisfied) subjects recruited by advertisement. Subjects were subsequently divided into two groups (head injured, nonhead injured) and these groups were also contrasted as a function of batterer status. Tests were administered to assess for cognitive and behavioral functions, including executive dysfunction, hypothesized to be a factor contributing to propensity for violence. Questionnaires and structured clinical interviews were used to assess marital discord, emotional distress, and violent behaviors. Batterers differed from nonbatterers across several cognitive domains: executive, learning, memory, and verbal functioning. Batterers were reliably discriminated from nonbatterers based on three neuropsychological tasks: Digit Symbol, Recognition Memory Test-Words, Wisconsin Card Sorting Test. Neuropsychological performance was the strongest correlate of domestic violence of all clinical variables measured. However, the inclusion of two other variables, severity of emotional distress and history of head injury, together with the neuropsychological indices provided the strongest correlation with batterers status. Among batterers, neuropsychological performance did not vary as a function of head injury status, indicating that while prior head injury was correlated with batterer status, it was not the sole basis for their impairments. The findings suggest that current cognitive status, prior brain injury, childhood academic problems, as well as psychosocial influences, contribute along with coexisting emotional distress to a propensity for domestic violence.

Achievement↗

Technetium-99m Q4: a prototype cationic perfusion radiotracer with myocardial washout.

Technetium-99m Q4 is derived from an existing mixed ligand myocardial tracer (99mTc-Q3) by the addition of an ester group to promote myocardial washout. Six subjects with single-vessel coronary disease documented by angiography and/or Q wave myocardial infarction documented by electrocardiography were studied with 99mTc-Q4 injection during exercise and with comparative thallium-201 tomography. Six healthy volunteers were also studied with 99mTc-Q4 imaging following injection at peak exercise. Tomographic images with 99mTc-Q4 and 201Tl each provided correct assessment of the presence or absence of coronary disease in 22 of 30 myocardial segments (73.3%). Six myocardial segments showed defect reversibility with 99mTc-Q4, whereas 14 segments showed reversibility with 201Tl, but the latter included three segments with no angiographic or electrocardiographic evidence of disease. In both normals and subjects with coronary artery disease, significant global washout of 99mTc-Q4 was observed over 4 h. For five patients with angiographic evidence of unrevascularized coronary artery stenosis, the ischemic to normal zone count ratio increased from 0. 782+/-0.107 at 45 min postexercise to 0.891+/-0.115 at 4 h postexercise (P = 0.016), suggesting occurrence of differential washout. It is concluded that addition of an ester group functionality to a previously studied mixed ligand cardiac tracer promotes global and regional myocardial tracer washout. Nevertheless, demonstration of perfusion defect reversibility with comparable frequency to that observed with 201Tl stress and reinjection images, required separate injections of 99mTc-Q4 at peak stress and at rest.

Adult↗

Public health implications of 1990 air toxics concentrations across the United States.

Occupational and toxicological studies have demonstrated adverse health effects from exposure to toxic air contaminants. Data on outdoor levels of toxic air contaminants have not been available for most communities in the United States, making it difficult to assess the potential for adverse human health effects from general population exposures. Emissions data from stationary and mobile sources are used in an atmospheric dispersion model to estimate outdoor concentrations of 148 toxic air contaminants for each of the 60,803 census tracts in the contiguous United States for 1990. Outdoor concentrations of air toxics were compared to previously defined benchmark concentrations for cancer and noncancer health effects. Benchmark concentrations are based on standard toxicological references and represent air toxic levels above which health risks may occur. The number of benchmark concentrations exceeded by modeled concentrations ranged from 8 to 32 per census tract, with a mean of 14. Estimated concentrations of benzene, formaldehyde, and 1,3-butadiene were greater than cancer benchmark concentrations in over 90% of the census tracts. Approximately 10% of all census tracts had estimated concentrations of one or more carcinogenic HAPs greater than a 1-in-10,000 risk level. Twenty-two pollutants with chronic toxicity benchmark concentrations had modeled concentrations in excess of these benchmarks, and approximately 200 census tracts had a modeled concentration 100 times the benchmark for at least one of these pollutants. This comprehensive assessment of air toxics concentrations across the United States indicates hazardous air pollutants may pose a potential public health problem.

Air Pollution↗

[Effects of micronized natural progesterone on the liver during the third trimester of pregnancy].

In France, prescription of micronized progesterone at high doses of 900 to 1200 mg/day is common practice in the case of preterm delivery, even though this is neither an indication nor a posology given for marketing authorisation. A few cases of gestational pruritus have been reported during such use, associated with cholestasic and/or cytolytic hepatic disorders. We report here the results of a controlled, double-blind study versus a placebo, aimed at assessing the effects on the liver of micronized progesterone administered orally at high doses (900-1200 mg/day), conducted in a population of 201 women presenting moderate menace of preterm delivery during the third trimester of pregnancy. 85 patients received micronized progesterone and 116 the placebo. The increase above normal levels of total biliary acids (TBA) and aminotransferases (ASAT, ALAT), was significantly more frequent in the micronized progesterone than in the placebo group. Among the 26 patients (14%) with a level of TBA superior to 10 mumoles/l during treatment, 18 belonged to the progesterone and 8 to the placebo group (p = 0.004); the 6 patients (3.4%) with increased ASAT were all under micronized progesterone (p < 0.001), as were the 10 patients (5.6%) with increased ALAT (p < 0.001). However, there is no statistically significant difference between the two groups regarding the occurrence of clinical manifestations (icterus, pruritus) which could be attributed to gravid cholestasis. We may conclude from this prospective study that, during the third trimester of pregnancy, micronized progesterone is associated with a significant risk of biological cholestasis. This would suggest that in patients genetically predisposed towards gravid cholestasis, micronized progesterone could be a factor favoursing this disease.

Adult↗

Experiences of battered women in health care settings: a qualitative study.

Interventions to help battered women seek and receive optimal health care must be informed by battered women's experiences in health care settings. In this study, we used a Systems Model to categorize the barriers battered women encounter in health care settings into patient, provider, and organizational levels. We conducted in-depth, face-to-face interviews with 31 battered women recruited by random digit dialing of households and by a publicity recruitment campaign. The data revealed that at the patient level, many women chose to conceal their abuse from their health care professionals, some fearing retaliation from their partners if they revealed the source of their injuries. At the provider level, the women perceived health care professionals to be disinterested or unsympathetic toward the needs of battered women, causing the women to feel ignored or trivialized. And at an organizational level, battered women believed that the structure of the health care system did not allow health care professionals enough time to deal with issues beyond treating their immediate presenting injuries. To ensure that battered women seek and receive optimal health care, multicomponent interventions should be designed to address the complex barriers at the three levels. We conclude by suggesting possible ways to help battered women get the tools they need to raise the issue of domestic violence with their health care professional. We also suggest ways to enable these professionals to identify battered women, validate their experiences, and provide appropriate referrals.

Adult↗