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Biomedical subjects

B Steinberg

Publications and source records attributed to B Steinberg.

At least 37 records · Page 2Linked to original sources

A force field evaluation tool for telephone service in ambulatory health care.

The tool presented here is useful in analyzing the constraints and capabilities of a health care telephone service. It also provides a systematic method for assessing systems problems. As part of our analysis, we recommended that the manager implement the following steps. First, the manager determines whether the driving force on the unit is continuity of care by an individual provider or consistency of response. This focus directly affects how the unit's telephone service can be best organized (i.e., decentralized or centralized) and clarifies the factors most needed for success. For example, to function effectively and efficiently, a centralized phone service needs strong provider-endorsed protocols. Second, the manager should carefully examine neutral constraint factors to determine methods to transform these constraints into capabilities, such as planning for extra staff or office hours (or both) during influenza season. Planning for extra hours or staff depends largely on whether budget and resource planning is done in advance and whether value is placed on customer access and satisfaction during peak demand periods. The manager must next determine whether the service delivery format (centralized or decentralized) is consistent with the force field analysis findings. If the findings are not consistent, can the analysis present a compelling argument for using the opposite approach? Finally, the manager must create a plan of action for minimizing the constraints revealed and maximizing existing capabilities to achieve the overall goal of excellent phone service. The process of analysis and creating a plan of action is an excellent opportunity to involve staff, providers, and administrators in efforts to achieve better health care telephone service for all customers.

Appointments and Schedules↗

Ultrastructural characteristics of a cell line derived from a melanotic neuroectodermal tumor of infancy.

Thin section and freeze-fracture transmission electron microscopy were used to examine and identify the cytoplasmic and membrane structures in a cell line derived from a melanotic neuroectodermal tumor of infancy (MNTI). The cultured cells had a uniform appearance after 70 population doublings characterized by long dendritic processes and evidence of melanin production. The cytoplasm contained numerous melanosomes in various stages of development, vesiculated rough endoplasmic reticulum, microfilaments and uncoated as well as coated vesicles. The membrane specializations included caveoli, coated pits, gap junctions, microfilaments, desmosome-like structures and lamellipodia. The ultrastructural appearance of the cultured MNTI cells was similar to features previously seen in electron micrographs of MNTI tumor specimens. However, correlated freeze-fracture and thin section micrographs permitted further identification of structures previously described. The MNTI cell line represents one of the cell types of the tumor and provides an opportunity for further study of the pathogenesis of this rare tumor.

Cell Line↗

Protein binding of active ingredients and comparison of serum ethinyl estradiol, sex hormone-binding globulin, corticosteroid-binding globulin, and cortisol levels in women using a combination of gestodene/ethinyl estradiol (Femovan) or a combination of desogestrel/ethinyl estradiol (Marvelon) and single-dose ethinyl estradiol bioequivalence from both oral contraceptives.

Results from two clinical pharmacokinetic studies are given. The first study was an observational study in oral contraceptive users who took either a combination of gestodene and ethinyl estradiol (pill A, Femovan) or desogestrel and ethinyl estradiol (pill B, Marvelon). A total of 69 women (39 receiving pill A and 30 receiving pill B) were evaluated to determine serum ethinyl estradiol, sex hormone-binding globulin, corticosteroid-binding globulin, and cortisol levels. Samples were obtained on 1 day during the tenth to twenty-first days of pill intake. All women received the respective oral contraceptive for at least 3 months. The test power was such that an 80% difference of 1 standard deviation of each target variable would have been detected (alpha = 0.05; beta = 0.1). No statistically significant differences were found in sex hormone-binding globulin, corticosteroid-binding globulin, or cortisol serum levels between both groups. Time and height of maximum ethinyl estradiol levels were identical as was the area under the curves. Ex vivo protein-binding analysis of the progestins revealed a free portion of 0.6% for gestodene and 2.5% for 3-ketodesogestrel as the active metabolite of desogestrel. Sex hormone-binding globulin-bound portions were much higher for gestodene (75.3% +/- 9.1%) than for 3-ketodesogestrel (31.6% +/- 12%). The remaining fractions were bound to albumin. In a second study, ethinyl estradiol-bioequivalence from pills A and B was investigated in 18 women in a controlled, single-dose, randomized, crossover design. The area under the ethinyl estradiol serum levels were identical up to 4 hours after pill intake between both treatments. According to the relatively low variation in data in this group of women, a 10% difference in ethinyl estradiol-availability could have been detected. Both studies indicate that the pharmacokinetics of ethinyl estradiol were independent of the concomitantly administered progestin, that is, desogestel and gestodene.

Adult↗

Assessment of criteria used in the histologic diagnosis of human papillomavirus-related disease of the female lower genital tract.

The goal of this study was to evaluate the histologic criteria used to establish the diagnosis of human papillomavirus (HPV)-associated disease, especially in borderline lesions. In a completely blinded study, 21 patients had one biopsy each of the cervix and vulva. Each specimen was evaluated by RNA and DNA in situ hybridization, a histologic diagnosis was rendered, and then each was evaluated for 12 histologic criteria commonly associated with HPV. On the cervix only binucleation and dysplasia correlated well with in situ hybridization. Koilocytosis correlated very strongly with the histologic diagnosis. On the vulva, koilocytosis, papillomatosis, elongated rete pegs, binucleation, and hypergranulosis correlated well with in situ hybridization. When four other pathologists reviewed the slides, they agreed on the histologic diagnosis and the presence of koilocytosis, binucleation, and dysplasia on the cervix but on none of the other criteria. On the vulva the pathologists disagreed on the overall diagnosis and the presence of any of the criteria with the exception of papillomatosis. Nonclassic histologic criteria should not, by themselves, be used to make the diagnosis of condyloma. The use of such terminology as "suggestive of condyloma" in histologic diagnoses should be avoided in favor of more descriptive terminology to avoid possibly unnecessary treatment for lesions of questionable significance.

DNA, Viral↗

Aetiology and diagnosis of clinically evident jaw trismus.

Trismus is a common problem presenting to the dental practitioner. It is usually of a benign nature; however a number of types can have serious implications. This review outlines the aetiology and diagnosis of clinically evident jaw trismus.

Humans↗

Comparison of serum ethinyl estradiol, sex-hormone-binding globulin, corticoid-binding globulin and cortisol levels in women using two low-dose combined oral contraceptives.

The study included 69 women taking a desogestrel (n = 30)- or gestodene (n = 39)-containing low-dose combined oral contraceptive for at least 3 months. Group size was calculated to detect a difference in mean values of 80% of 1 standard deviation (alpha = 0.05, beta = 0.1). Seven serum samples were obtained up to 4 h, and 1 sample 24 h, after drug intake on 1 day between the 10th and the 21st day of the cycle. The concentrations of sex-hormone-binding globulin (SHBG), corticoid-binding globulin (CBG) and cortisol were measured in a 0- to 4-hour serum pool by radioimmunoassay. Ethinyl estradiol (EE2) levels were analyzed in single and pooled samples using anti-EE2-6 beta-carboxymethyloxime-bovine serum albumin antiserum. The area under the curves (AUC) up to 4 and 24 h and Cmax and tmax were evaluated. Statistical analysis (analysis of covariance) did not reveal a dependence of values on duration of treatment or day of cycle. Both treatments resulted in almost identical values for all parameters evaluated. The mean levels of SHBG, CBG and cortisol were in the range of 186-226 nmol/l, 89-93 mg/l and 280-281 micrograms/l, respectively. Mean maximum EE2 levels of 106-129 pg/ml were found 1.6-1.8 h after pill intake and AUC0-4 h accounted for 329-374 pg.h.ml-1. The recently reported differences in serum EE2 and CBG levels between two groups of 11 women each treated with desogestrel- and gestodene-containing pills, respectively, could not be confirmed.

Adult↗

Relative bioavailability of ethinyl estradiol from two different oral contraceptive formulations after single oral administration to 18 women in an intraindividual cross-over design.

Two low-dose oral contraceptives, both containing the same dose of ethinyl estradiol (EE2) but different progestins (gestodene and desogestrel, respectively), were compared with respect to the relative bioavailability of EE2. After single-dose administration of both formulations to 18 women in an intraindividual cross-over design, there was no difference in the target variables for EE2 (Cmax, tmax and AUC). With respect to EE2, both formulations were bioequivalent. The observation of others, reporting higher EE2 levels in the serum of women taking the gestodene-containing formulation as compared to those taking the desogestrel-containing formulation, was not confirmed.

Adult↗

Detection of conditions related to human papillomavirus. Comparison of cytology, colposcopy, histology and hybridization.

The diagnosis of lesions associated with human papillomavirus infection can be difficult because the results of the tests used can be contradictory. Our goal was to compare some of these tests and to evaluate their comparative strengths and weaknesses as clinically useful tools in confirming the diagnosis, especially in borderline cases. Twenty-one consecutive patients from our colposcopy clinic were screened with cytology and colposcopy. Biopsies were taken from representative areas on the cervix and vulva and divided. One-half was evaluated with Southern blot hybridization and the other half with histology and with RNA and DNA in situ hybridization. Cytology and histology were interpreted as either "positive" (showing definite evidence of human papillomavirus infection or cervical intraepithelial neoplasia [CIN]), "negative" (showing no evidence of human papillomavirus infection or CIN) or "equivocal" (atypical [class II] Papanicolaou smears or histology suggestive but not diagnostic of condyloma). In order to determine the clinical significance of equivocal results the sensitivity and specificity of these tests were calculated, with the equivocal results reclassified as either positive or negative. Colposcopy was the most sensitive technique but was not very specific. Cytology was a very sensitive screening tool when the atypical (class II) smears were considered positive but not when they were considered negative. The specificity of the histologic diagnosis was doubled with the equivocal results considered negative when compared to the specificity of the histologic diagnosis with the equivocal results considered positive, with no loss of sensitivity. Each technique has drawbacks, and therefore no one should be used to diagnose and treat these lesions to the exclusion of all others.

Biopsy↗

A study of facially expressed emotions as a function of age, exposure time, and sex in children.

Facial expressions and body language constitute a major component of communication in the human population. There are no studies in the dental literature that have examined children's ability to recognize facial expressions. The purpose of this study was to determine children's accuracy and latency to respond to facial expressions (photographs) as a function of age and sex. Sixty children were recruited randomly and placed into three groups according to their age (3, 6, and 9 years) with 20 children per group. They were shown photographs of three different emotions (happiness, anger, and sadness) expressed by actors at three different exposure times (0.2, 0.5, and 1.0 sec), tachistoscopically. The children's responses (accuracy and latency) were recorded. The results indicated that three year olds were significantly less accurate and took longer to respond than the older children. Factors that may have influenced the results and clinical implications are discussed.

Age Factors↗

Human papillomavirus 6/11 and 16/18 in Schneiderian inverted papillomas. In situ hybridization with human papillomavirus RNA probes.

Schneiderian inverted papillomas may be troublesome lesions for clinicians with propensity for recurrences. Dysplasia is not uncommonly seen, and some of these lesions do progress to develop squamous carcinoma. The authors hybridized in situ seven inverted papillomas with RNA probes to human papillomavirus (HPV) 6, 11, 16, and 18. Four of these contained dysplasia, two were without dysplasia, and one contained invasive squamous cell carcinoma. Five inverted papillomas showed evidence of HPV infection based on hybridization. One with mild to moderate and one with severe dysplasia, and one without dysplasia hybridized with mixed probe HPV 6/11. One with mild dysplasia and one associated with invasive squamous cell carcinoma hybridized with mixed probe HPV 16/18. One inverted papilloma without dysplasia and one with severe dysplasia did not definitively hybridize with either mixed probe. These findings raise interesting questions as to role of HPV 6/11 and 16/18 in the development of inverted papillomas, and probably on the progression to and carcinoma.

Adult↗

Transfusion history, T cell subsets and natural killer cytotoxicity in patients with colorectal cancer.

Blood transfusions are associated with clinical phenomena which are attributable to immune suppression. Since suppression of immune function is associated with a high risk of spontaneous malignancies, we studied T cell subsets and natural killer (NK) cytotoxicity in colorectal cancer patients and correlated the results with patients' transfusion histories. Twelve percent (14) of the 115 patients had been transfused an average of 19 years previously. Recipients of blood transfusions had low levels of peripheral lymphocytes (p = 0.191), T cells (p = 0.015), helper cells (p = 0.016) and suppressor cells (p = 0.2651) compared to previously untransfused patients. NK cytotoxicity was also significantly reduced in transfusion recipients although NK cell numbers were comparable in both groups. These results support previous studies indicating that blood transfusions cause lifelong immune modulation in the recipient. Since blood transfusions have numerous beneficial effects and immune modulation is often beneficial, longitudinal studies are necessary to define the lifetime risks and benefits.

Aged↗

Effect of norfloxacin on theophylline metabolism.

The purpose of this study was to investigate the effect of norfloxacin on theophylline elimination. Ten normal volunteers were studied. In a randomized crossover sequence, each subject received 6 mg of aminophylline per kg of body weight by a 30-min intravenous infusion on day 4 of taking norfloxacin (400 mg every 12 h) or while drug free. Mean theophylline clearance decreased and mean elimination half-life increased after norfloxacin administration (from 0.036 +/- 0.006 to 0.033 +/- 0.004 liter/h per kg and from 8.7 +/- 1.2 to 9.5 +/- 1.5 h, respectively; P less than 0.05, Wilcoxon signed-ranks test). We conclude that norfloxacin taken in recommended doses for 3 days has a small inhibitory effect on theophylline metabolism that would probably not cause clinically important elevations in theophylline concentrations in most patients.

Adult↗

[Effects of low molecular weight hydroxyethyl starch (HES 40) in comparison with Ringer solution on oxygen tension in skeletal muscles of infected patients].

Volume expansion for the establishment of normal to slightly hyperdynamic systemic circulation has become part of a standard concept in the treatment of septicemic patients. The goal is an improvement of microcirculation with beneficial effects on tissue oxygen supply. This study investigates the effect of hydroxyethyl starch solution (HES 6%: mean molecular weight = 40,000) versus ringer's solution on tissue oxygen tensions in human skeletal muscle during periods of septicemia in 10 mechanically ventilated ICU-patients. Measurement of tissue oxygen tension was achieved by a polarographic pO2-sensitive flexible probe. After computer assisted analysis pO2-histograms were calculated out of 200 single pO2-values measured consecutively within a time period of 4 min. Infusions of 500 ml ringer's solution or 500 ml HES were given over 60 min in each patient in a randomized order. The second infusion was begun when the pO2-histogram had reproducibly regained control values as measured before treatment. Measurements were made every 30 min after starting the infusion for a total period of 150 min. As a result the median pO2 improved by 24.5% 90 min after the infusion of HES was begun with a simultaneous significant (30 to 150 min; p less than 0.05) drop in hematocrit from 34.3% to 32.4%. In contrast ringer's solution had no significant effect on tissue pO2 whereas the hematocrit was comparable to the HES group in the time period of 30-60 min. In both groups no linear correlation between hematocrit and pO2-tensions could be established. It remains unclear if pO2-tensions during and after HES infusion can be correlated to an improved capillary perfusion. However, as was clearly demonstrated, different types of solutions used for volume expansion may exert different effects on pO2-tissue tension in septic patients.

Adult↗

Melanotic neuroectodermal tumor of infancy: evidence for multicentricity.

The melanotic neuroectodermal tumor of infancy (MNTI) is a rare neoplasm that is believed to be derived from cells of the neural crest. This case demonstrates a multicentric distribution of the MNTI. The possibility of a multicentric variant of benign MNTI is discussed with respect to both the present case and previously described reports. Suggestions for evaluation and surgical management are given.

Alveolar Process↗

The prognostic significance of natural killer cytotoxicity in patients with colorectal cancer.

We evaluate the prognostic significance of preoperative natural killer (NK) cytotoxicity for K562 cells and its relationship to other prognostic factors in 102 patients with colorectal cancer who underwent curative resections between February 1984 and February 1985. The 18 patients who had recurrences within two years of surgery had significantly higher numbers of preoperative peripheral blood suppressor/cytotoxic and NK cells and significantly lower preoperative NK cytotoxicity than disease-free patients. Low preoperative NK cytotoxicity was predictive of recurrence independent of age, sex, hematocrit, procedure, blood loss, duration of surgery, Dukes' stage, specimen length, tumor size, tumor differentiation, and post-operative therapy. Low levels of in vitro NK-cell cytotoxicity may identify a subgroup of patients at high risk for recurrence.

Aged↗

Popliteal pterygium syndrome.

Popliteal pterygium syndrome (PPS) is a rare congenital disorder consisting of limb, genital, and orofacial malformations. Approximately fifty cases have been described, and the extremely variable nature of this syndrome has been shown. Two new cases of PPS are reported in this article. Surgical management and airway control are also described.

Abnormalities, Multiple↗

P NMR evaluation of hypoxic stress in brain of animal models.

Quantification by NMR of hypoxic stress is best afforded by the ratio of phosphocreatine (PCr) to inorganic phosphate (Pi). The thin cranium and sternum of neonates affords ideal conditions for NMR evaluation of impaired oxidative metabolism. Brains of animal models (dog and cat) are best studied with muscles retracted with the rf coil placed on the bare skull. 31P and 1H (lactate) signals are time shared with a doubly tuned coil. Servo-stabilized hypoxia gives simplified steady state analysis. Hypoxic insults of the brain are evaluated by the integral of the deviation of the PCr/Pi ratio from the normoxic values. Generally, a deviation of 1 unit of PCr/Pi for an interval of 3 hr will lead to a severe metabolic damage and recovery from hypoxia is often 30-fold delayed. Comprehensive monitoring of energy metabolism (PCr/Pi), respiratory chain redox states, intracellular pH and lactate accumulation allow the calculation of integrated pH and lactate "insults" and thus offer new insights on the effects of hypoxia on brain oxidative metabolism.

Animals↗