Hospital reorganization after merger

Major organizational changes among hospitals, like system affiliation, merger, and closure, would seem to offer substantial opportunities for hospitals and health systems to be strategic in the local reconfiguration of health services. This report presents the results of a unique survey on what happened to hospitals after mergers occurring between 1983 and 1988, inclusive. Building on an ongoing verification process of the American Hospital Association, surviving institutions from all 74 mergers that occurred during the study frame were surveyed in the fall of 1991. Responses were received from 60 of the 74 mergers (81%), regarding the primary, postmerger use of the hospitals involved. Topics surveyed included the premerger competition between the hospitals and in their environment, and what happened to the hospitals after their mergers. Mergers frequently served to convert acute, inpatient capacity to other functions, with less than half of acquired hospitals continuing acute services after merger. In the context of health care reform, mergers may offer an expeditious way locally to restructure health services. Evidence on the postmerger uses of hospitals and about the reasons given for merger suggests that mergers may reflect two general strategies: elimination of direct acute competitors or expansion of acute care networks.     

Minimally invasive cardiac surgical techniques in the closure of ventricular septal defect: an alternative approach

BACKGROUND: Minimally invasive cardiac surgical techniques recently have been applied in the management of a variety of intracardiac lesions. METHODS: Fourteen patients (6 boys and 8 girls; age, 8.9 +/- 5.5 years; body weight, 29.0 +/- 13.5 kg) were operated on using minimally invasive cardiac surgical techniques for the closure of a ventricular septal defect (subarterial in 11 patients and perimembranous in 3 patients). The operations were performed through a left anterior minithoracotomy and were guided by video-assisted endoscopic techniques under femorofemoral cardiopulmonary bypass. The myocardium was protected by continuous coronary perfusion with hypothermic fibrillatory arrest. The right ventricular outflow tract was entered after pericardiotomy was performed. RESULTS: Closure of the defect (directly in 4 patients and by patch in 10 patients) was performed successfully in all patients. A right ventricular outflow tract obstruction and ruptured sinus of Valsalva aneurysm also were repaired in 1 patient each. The duration of cardiopulmonary bypass was 41 +/- 10 minutes (range, 28 to 100 minutes) and the total operative time was 2.2 +/- 0.8 hours (range, 1.3 to 3.5 hours). All the patients recovered rapidly from their operation and had an uneventful postoperative course. Follow-up (mean, 6.2 months; range, 6 to 9 months) was complete in all patients. There were no late deaths. Transthoracic echocardiographic examination showed no residual shunt and no aortic regurgitation in all patients. CONCLUSIONS: Our experience demonstrates that minimally invasive cardiac surgical techniques are technically feasible and an alternative option for the repair of a ventricular septal defect.     

Implantable hearing device performance measured by laser Doppler interferometry

Recent application of the Doppler principle laser interferometry to audiology, acoustics and otology has facilitated the development of implantable hearing devices (IHDs). During the design and testing of two different electromagnetic middle ear implants for sensorineural hearing loss, we used single-point laser Doppler interferometry (LDI). A commercially available interferometer, internally calibrated and validated against a National Institute for Standards and Technology (NIST) standard, was used with both mechanical fixtures and fresh temporal bones to evaluate implant mass, shape and orientation, attachment, electromagnetic coupling and acoustic properties. At both Hough Ear Institute and Symphonix Devices, Inc., we have shown that high fidelity and amplitudes can be recorded in vitro over a frequency range of 500 Hz to 10 kHz. These data can provide greater assurance of safety and efficacy to regulatory agencies before entering clinical trials. We propose that LDI be considered as an international standard for accurate, consistent comparison of performances of all IHDs during development. Furthermore, the future availability of human IHD data will allow for the extrapolation of a mechanical bench model of the middle ear transfer function for use in quality control during manufacturing and diagnosis of failure in IHDs.     

Identification of a membrane-spanning domain of the thiol-activated pore-forming toxin Clostridium perfringens perfringolysin O: an alpha-helical to beta-sheet transition identified by fluorescence spectroscopy

Clostridium perfringens perfringolysin O (PFO or theta-toxin) is a cytolytic toxin that binds to cholesterol-containing membranes and then self-associates to spontaneously form aqueous pores of varying size in the bilayer. In this study, a membrane-spanning domain has been identified in PFO by a combination of fluorescence spectroscopic methods using the fluorescent dye N, N'-dimethyl-N-(iodoacetyl)-N'-(7-nitrobenz-2-oxa-1, 3-diazolyl)ethylenediamine (NBD) whose emission properties are sensitive to water. PFO was substituted with a single cysteine at most of the residues between amino acids K189 and N218, and then each cysteine was modified with NBD. Each purified NBD-labeled PFO was then bound to membranes, and the probe's environment was ascertained by measuring its fluorescence lifetime, emission intensity, and collisional quenching with either aqueous (iodide ions) or nonaqueous (nitroxide-labeled phospholipids) quenchers. Lifetime and intensity measurements revealed that the amino acid side chains in this region of the membrane-bound PFO polypeptide alternated between being in an aqueous or a nonaqueous environment. This pattern indicates that this portion of the membrane-bound PFO spans the membrane in an antiparallel beta-sheet conformation. The alternating exposure of these residues to the hydrophobic interior of the bilayer was demonstrated by their susceptibility to quenching by nitroxide moieties attached to phospholipid acyl chains. Residues K189-N218 therefore form a two-stranded, amphipathic beta-sheet in the membrane-bound PFO that creates a stable interface between the pore and the membrane. This same region packs as three short alpha-helices in the soluble, monomeric form of PFO, and therefore, the cholesterol-dependent conversion of PFO to a membrane-bound oligomer involves a major structural transition in which three alpha-helices unfold to form a membrane-spanning amphipathic beta-sheet.     

Retrobulbar anesthesia for repair of ruptured globes

PURPOSE: To describe two cases involving patients with ruptured globes in whom retrobulbar anesthesia was used successfully. METHOD: A modified retrobulbar anesthesia technique was used to repair two ruptured globes in two patients in whom general anesthesia was contraindicated. RESULT: Using a modified technique, retrobulbar anesthesia did not cause wound gape or prolapse of intraocular contents. CONCLUSIONS: Most open globes should be repaired after administration of general anesthesia. Modified retrobulbar anesthesia can provide a reasonable alternative in rare situations in which general anesthesia subjects the patient to an unacceptable risk.     

Popliteal aneurysm presenting as acute thrombosis and ischemia in a middle-aged man with a history of Kawasaki disease

Kawasaki disease is known to cause a vasculitis of small and medium-sized vessels, with subsequent aneurysm formation. Most of the severe manifestations of the disease occur as a result of coronary aneurysm formation. However, many other arteries have been documented to be involved. A case is presented of a middle-aged man with a history of Kawasaki disease who had an acute ischemic limb from a thrombosed popliteal aneurysm that formed as a result of the disease. This is the first known case report of Kawasaki disease resulting in delayed lower extremity ischemia. Typical findings of patients with Kawasaki disease are presented, along with a case report and review of the literature. A history of Kawasaki disease is an extremely rare but possible cause of peripheral aneurysms, even in middle-aged patients.     

Stimulation of type 1 and type 8 Ca2+/calmodulin-sensitive adenylyl cyclases by the Gs-coupled 5-hydroxytryptamine subtype 5-HT7A receptor

The neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) plays an important regulatory role in developing and adult nervous systems. With the exception of the 5-HT3 receptor, all of the cloned serotonin receptors belong to the G protein-coupled receptor superfamily. Subtypes 5-HT6 and 5-HT7 couple to stimulation of adenylyl cyclases through Gs and display high affinities for antipsychotic and antidepressant drugs. In the brain, mRNA for 5-HT6 is found at high levels in the hippocampus, striatum, and nucleus accumbens. 5-HT7 mRNA is most abundant in the hippocampus, neocortex, and hypothalamus. To better understand how serotonin might control cAMP levels in the brain, we coexpressed 5-HT6 or 5-HT7A receptors with specific isoforms of adenylyl cyclase in HEK 293 cells. The 5-HT6 receptor functioned as a typical Gs-coupled receptor in that it stimulated AC5, a Gs-sensitive adenylyl cyclase, but not AC1 or AC8, calmodulin (CaM)-stimulated adenylyl cyclases that are not activated by Gs-coupled receptors in vivo. Surprisingly, serotonin activation of 5-HT7A stimulated AC1 and AC8 by increasing intracellular Ca2+. 5-HT also increased intracellular Ca2+ in primary neuron cultures. These data define a novel mechanism for the regulation of intracellular cAMP by serotonin.     

Efficacy of radical hysterectomy as treatment for patients with small cell carcinoma of the cervix

BACKGROUND: This study was performed to identify pathologic and clinical features that best predict disease free survival of patients with early stage small cell carcinoma of the cervix treated by radical hysterectomy. METHODS: Three hundreds and seventy patients with cervical carcinoma were analyzed retrospectively to define those variable that best predict disease free survival (DFS). Variables included age, weight, race, marital status, economic status, tumor size, depth of invasion (DI), lymph-vascular space involvement (LVSI), cell type, tumor grade, lymph node metastasis (LNM), and total number of lymph nodes removed. Patients with lymph node metastasis, parametrial involvement, and positive or close surgical margins were offered postoperative radiation. RESULTS: Twelve patients were found to have small cell carcinoma (3.2%). One patient had microinvasive carcinoma of the cervix (MIC) as defined by the Society of Gynecologic Oncologists with a depth of invasion of 3 mm or less and no lymph-vascular space invasion, and has been reported previously. A detailed analysis of the other patients with nonsmall cell carcinoma is presented separately. Five patients achieved a DFS of at least 5 years, whereas 7 patients died with disease. Excluding the patient with MIC, the 5-year DFS rate was 36.4%. CONCLUSIONS: Relative to other cell types, small cell carcinomas of the cervix is an aggressive neoplasm with a higher rate of LVSI and LNM despite smaller DI and tumor size. These data suggest that multimodality therapy, combining radical surgery and radiation with cytotoxic chemotherapy, may provide these patients with the best chance for cure.     

The population risk as an explanatory variable in research synthesis of clinical trials

The population risk, for example the control group mortality rate, is an aggregate measurement of many important attributes of a clinical trial, such as the general health of the patients treated and the experience of the staff performing the trial. Plotting measurements of the population risk against the treatment effect estimates for a group of clinical trials may reveal an apparent association, suggesting that differences in the population risk might explain heterogeneity in the results of clinical trials. In this paper we consider using estimates of population risk to explain treatment effect heterogeneity, and show that using these estimates as fixed covariates will result in bias. This bias depends on the treatment effect and population risk definitions chosen, and the magnitude of measurement errors. To account for the effect of measurement error, we represent clinical trials in a bivariate two-level hierarchical model, and show how to estimate the parameters of the model by both maximum likelihood and Bayes procedures. We use two examples to demonstrate the method.