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Biomedical subjects

M Singer

Publications and source records attributed to M Singer.

359 records · Page 20Linked to original sources
PubMedDate not supplied

Recurrent squamous cell carcinoma of the true vocal cord.

None of the consultants disagree with the initial plan to treat this T1N0 squamous cell carcinoma of the true vocal cord with radiotherapy. The consensus is that 10% to 20% of these lesions can fail conventional treatment. Dr. Rice cites incorrect radiotherapy ports, understaging, and extension into muscle or cartilage as the likely reasons for failure. He also believes that a patient who continues to smoke is at risk for persistent or recurrent disease. Drs. Wetmore and Singer add that some tumors are radioresistant for indefinable reasons. Although all the consultants agree that the differentiation between severe atypia and carcinoma in situ can be very difficult, Dr. Singer warns that the surgeon should not play a role in the histologic decision-making. He does not make a distinction between the two and suggests treating a lesion on the basis of its clinical behavior. Dr. Rice draws the line at treating T3 glottic carcinomas with radiotherapy. He states that the greater the tumor bulk the less well the lesion will do with radiotherapy. All the experts caution that involvement of cartilage at the anterior commissure and arytenoid is also a reason for failure. Dr. Wetmore adds that subglottic extension and verrucous carcinoma also contribute to radiotherapy failure. The real controversy lay with how to proceed in this case. Dr. Rice suggests excision of the lesion with the laser or microsurgical stripping. If the margins were positive he would proceed with a vertical hemilaryngectomy. Dr. Wetmore would excise the lesion with a CO2 laser and would follow the patient closely thereafter. He would only plan a hemilaryngectomy if the lesion recurred again.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMedDate not supplied

HIV serostatus and risk behaviors in a multisite sample of drug users.

In developing HIV prevention efforts, it is critical to determine whether interventions are effective in achieving declines in risk behavior among both HIV-positive and HIV-negative individuals. Based on a multisite intervention study of injection drug users (IDUs) and crack smokers, 488 seropositive IDUs and 364 seropositive crack users were compared with randomly selected matched samples of seronegatives (with matching based on recruitment site, gender, age group and ethnicity) at baseline and six-month follow-up to compare changes in risk behaviors by serostatus. Results indicated that overall, risk behaviors declined substantially over time; significant interaction effects indicated that seropositives reported a greater decline in sex risk behaviors than seronegatives. These data support the utility of HIV testing for high-risk drug users, and indicate that interventions have produced reductions in risk behaviors of both seropositives and seronegatives. Further research on the impact of site seroprevalence, and to enhance our understanding of those who continue to engage in risky behaviors, is needed.

Adolescent↗
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Correlation between halothane-induced myocardial depression and decreases in La3+-displaceable Ca2+ in cardiac muscle cells.

The relationship between myocardial contractility and the amount of La3+-displaceable Ca2+ was studied in the presence and absence of halothane using dog trabecular muscle. The La3+-displaceable Ca2+ is believed to represent surface-located Ca2+ which enters the cytoplasm and interacts with the contractile proteins during membrane depolarization. It was found that there was a linear relationship between the halothane-induced decrease in contractility and the reduction in the amount of La3+-displaceable Ca2+. Additional data suggest that halothane increases the Ca2+ binding of the plasma membrane, thereby decreasing the availability of the surface-located Ca2+.

Animals↗
PubMedDate not supplied

Operant control of alpha EEG and the effects of illumination and eye closure.

The effects of eyelid position (open or closed) and three levels of room illumination on operant control of alpha EEG were investigated utilizing a factorial design. After base-line levels were determined, subjects were given alpha-contingent feedback and instructed to increase and decrease alpha production during six successive 4-min intervals. In addition, a comparison was made between percent time and average amplitude as dependent measures. The percent time data indicated that eyes-open training facilitated alpha enhancement and suppression. However, this was not supported by the average amplitude data. Ambient illumination, regardless of the measure utilized, facilitated alpha training, particularly when the eyes were open. These results are related to previous research and theoretical issues.

Acoustic Stimulation↗
PubMedDate not supplied

Integration of multidisciplinary sensory data: a pilot model of the human brain project approach.

The paper provides an overview of neuroinformatics research at Yale University being performed as part of the national Human Brain Project. This research is exploring the integration of multidisciplinary sensory data, using the olfactory system as a model domain. The neuroinformatics activities fall into three main areas: 1) building databases and related tools that support experimental olfactory research at Yale and can also serve as resources for the field as a whole, 2) using computer models (molecular models and neuronal models) to help understand data being collected experimentally and to help guide further laboratory experiments, 3) performing basic neuroinformatics research to develop new informatics technologies, including a flexible data model (EAV/CR, entity-attribute-value with classes and relationships) designed to facilitate the integration of diverse heterogeneous data within a single unifying framework.

Amino Acid Sequence↗
PubMedDate not supplied

Unbundling the corporation.

No matter how monolithic they may seem, most companies are really engaged in three kinds of businesses. One business attracts customers. Another develops products. The third oversees operations. Although organizationally intertwined, these businesses have conflicting characteristics. It takes a big investment to find and develop a relationship with a customer, so profitability hinges on achieving economies of scope. But speed, not scope, drives the economics of product innovation. And the high fixed costs of capital-intensive infrastructure businesses require economies of scale. Scope, speed, and scale can't be optimized simultaneously, so trade-offs have to be made when the three businesses are bundled into one corporation. Historically, they have been bundled because the interaction costs--the friction--incurred by separating them were too high. But we are on the verge of a worldwide reduction in interaction costs, the authors contend, as electronic networks drive down the costs of communicating and of exchanging data. Activities that companies have always believed were central to their businesses will suddenly be offered by new, specialized competitors that won't have to make trade-offs. Ultimately, the authors predict, traditional businesses will unbundle and then rebundle into large infrastructure and customer-relationship businesses and small, nimble product innovation companies. And executives in many industries will be forced to ask the most basic question about their companies: What business are we really in? Their answer will determine their fate in an increasingly frictionless economy.

Commerce↗
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Unexpected deaths and referrals to intensive care of patients on general wards. Are some cases potentially avoidable?

OBJECTIVES: (i) To determine the incidence of unexpected deaths occurring on general wards, and whether any were potentially avoidable; (ii) to assess whether the quality of care on general wards prior to admission to intensive care affected subsequent outcome. DESIGN: Six-month audit in teaching hospital. Review of medical, nursing and physiotherapy notes, bedside charts and laboratory data in ward patients either dying unexpectedly (i.e. not having a prior 'do not resuscitate' order) or requiring intensive care unit (ICU) admission. Panel assessment of quality of ward care prior to unexpected ward death or ICU admission. SUBJECTS: Adult general ward patients admitted to ICU or dying unexpectedly. OUTCOME MEASURES: ICU and hospital mortality. RESULTS: (i) In the six-month study period, 317 of the 477 hospital deaths occurred on the general wards, of which 20 (6%) followed failed attempts at resuscitation. Thirteen of these unexpected deaths were considered potentially avoidable: gradual deterioration was observed in physiological and/or biochemical variables, but appropriate action was not taken; (ii) in the same period, 86 hospital inpatients were admitted on 98 occasions to the ICU, 31 of whom received suboptimal care pre-ICU admission due either to non-recognition of (the severity of) the problem or to inappropriate treatment. Both ICU (52% vs 35%) and hospital (65% vs 42%) mortality was significantly higher in these patients compared to well managed patients (p < 0.0001). CONCLUSIONS: Patients with obvious clinical indicators of acute deterioration can be overlooked or poorly managed on the ward. This may lead to potentially avoidable unexpected deaths or to a poorer eventual outcome following ICU admission. Early recognition and correction of abnormalities may result in outcome benefit, but this requires further investigation.

Adolescent↗
PubMedDate not supplied

Serum amyloid protein (SAP) as a marker of autoimmune disease in mice.

Acute phase proteins are good markers of inflammatory processes. To clarify whether Serum Amyloid Protein (SAP) can be a marker for the onset of SLE disease in mice, we measured constitutive and inducible SAP levels in normal mice of different strains, in C57Bl/6 lpr/lpr (B6lpr) and [NZB x NZW]F1 (NZB/W) SLE-prone mice, in mice that develop Lupus-like syndrome during chronic Graft versus Host (GvH) reaction and in mice suffering acute GvH reaction. In comparison to B6lpr, NZB/W mice showed higher blood levels of SAP but those levels did not correlate with autoimmune parameters. In B6lpr, the SAP levels steadily increased with age and correlated with some of the parameters used for monitoring the SLE disease. High levels of SAP were also found in mice suffering acute GvH reaction whereas the lupus-like chronic GvH disease was associated with limited increase of SAP levels.

Age of Onset↗
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Local control after the use of adjuvant electron beam intraoperative radiotherapy in patients with high-risk head and neck cancer: the UCSF experience.

PURPOSE: We assess the effect of electron beam intraoperative radiotherapy (EB-IORT) on local-regional control and any associated complications in patients with locally advanced or recurrent head and neck cancer. MATERIALS AND METHODS: The records of 30 patients with head and neck cancer who received EB-IORT from March 1991 to December 1994 were retrospectively reviewed. The indications for EB-IORT in 25 patients were recurrent or persistent disease despite previous treatment with full-course external-beam radiotherapy and/or one or more resections. In five other cases the indication was extensive primary disease with multiple high-risk factors for local recurrence, including extension into the base of the skull, advanced extensive disease, and perineural or bony invasion. All patients had a Karnofsky performance score > or = 70 prior to EB-IORT. Median age was 65 years. Final pathology revealed positive or close surgical margins in all patients. The areas treated were generally inaccessible to catheter placement for brachytherapy. The most common histology was squamous cell carcinoma. EB-IORT was given as a single fraction of 1500 cGy to the 90% isodose with 6 or 9 Mev electrons using cone sizes ranging from 2.5 to 7 cm in diameter. Data were analyzed to determine the local-regional control rate, survival, and complications after EB-IORT. RESULTS: With a median follow-up time of 30 months, nine patients (27%) had only local recurrence. Of these, only one recurrence was inside the EB-IORT field and eight were outside the EB-IORT field. Two patients (7%) developed distant metastases only and one patient (3%) had both local recurrence and distant metastasis. Seven patients died, five with disease. Twenty-two patients are known to be alive, 15 (68%) of whom have no evidence of disease. One patient was lost to follow-up after 12 months; when last examined he was free of disease. Five patients (16%) have had mild-to-moderate transient complications probably related to EB-IORT. The 3-year actuarial local-regional control rate was 60%. CONCLUSIONS: Our data suggest that EB-IORT may play an important role in decreasing local recurrence in patients with multiple high-risk factors. Despite previous full-course external beam radiotherapy and extensive resections, EB-IORT did not confer significant additional long-term morbidity. Although results are encouraging, randomized studies are required to definitively establish the role of EB-IORT in the management of advanced or recurrent head and neck cancer.

Adenocarcinoma↗
PubMedDate not supplied

Insertion of a pulmonary artery flotation catheter: how to do it.

This article outlines a safe and successful technique of inserting the pulmonary artery catheter. Readers should regard it as a supplement, not a substitute, to bedside instruction by an experienced and competent clinician.

Catheterization, Swan-Ganz↗