Fabrication of a laser-welded fixed-detachable prosthesis for immediate loading.

Immediate loading of dental implants in completely edentulous patients is receiving great attention. Standard surgical protocol is used with primary stabilization of the implants as a goal. The restorative dentist must coordinate with the surgeon and the laboratory technician to make immediate loading a reality for the completely edentulous patient. This article describes a technique developed to fabricate an immediately loaded fixed-detachable prosthesis using laser welding technology. Advantages, which are applicable to various implant systems and patients, are discussed.

Scientific vs. clinical-based knowledge in psychology: a concealed moral conflict.

Psychology and the other mental health professions are bitterly divided between the proponents of scientific vs. clinical-based knowledge. Though these two groups agree on little related to assessment, treatment or outcome evaluation, they share a belief in the moral neutrality of the knowledge they do possess. It is argued here that this moral neutrality is a myth, and that it is exactly the unacknowledged and incompatible moral positions inherent in clinical and research practices that are at the center of this controversy. The nature of moral problems, the fundamental moral value positions prevalent in our culture, and the specific moral values associated with each side of this schism are explored. While these moral differences may not all be resolved by being recognized and discussed, the process of dialogue can not but help us bridge the current chasm. To this end it is recommended that psychologists and other mental health professionals adopt a "truth-in-moral-packaging" rule that requires both clinicians and scientific researchers to define openly and clearly the moral objectives that infuse their work.

Marriage and family therapists evaluate managed mental health care: a qualitative inquiry.

This study examined the experiences of 26 marriage and family therapists working in managed mental health care. A qualitative strategy was used to explore therapists' perspectives regarding practice in a managed care environment. Using an open-ended, semi-structured, mailed questionnaire four themes emerged from the data. These are the adaptations of clinical practice, issues of treatment duration/abandonment, effects of managed care on the therapeutic relationship, and issues of diagnosis. Recommendations are drawn from the findings and discussed.

Evaluation of interarch space for implant restorations in edentulous patients: a laboratory technique.

This article describes a laboratory procedure for the visual evaluation of interarch space and its effect on implant prosthesis design. The method is applicable to patients presenting with completely edentulous arches. Silicone impression material is used to form a resilient cast and an external mold from an existing denture. The denture is duplicated using autopolymerizing acrylic resin. The duplicate denture and resilient cast are mounted on an articulator. Spatial relationships of anatomic landmarks can be evaluated, and a quantitative evaluation of available space can be made. The duplicate denture can also be used as a surgical template to direct implant placement. Reference tables are provided to serve as guidelines in the correlation between available space and minimum space required for various implant-assisted restorations.

Vagal paraganglioma: the Jefferson experience.

Vagal paraganglioma is a rare tumor of neural crest origin. Although the literature is in agreement with regard to epidemiology, diagnosis, and tumor biology, there is some controversy over treatment modalities for these patients. We performed a nonrandomized retrospective study in a large single-institution series of patients (n = 19) in whom vagal paraganglioma was diagnosed. General statistics included age, male/female ratio, tumor size, and duration of follow-up. Other variables such as signs and symptoms at presentation, family history, multicentricity, metastatic disease, and secretion of catecholamines were included. CT scan, MRI, and angiography were used in combination for diagnostic purposes as well as for treatment planning. Preoperative embolization was performed in 5 of the more recently treated patients. Current issues regarding the use of preoperative embolization and choice of surgical approach were analyzed. In this article the possibility and sequela of vagus nerve-sparing procedures will be presented. Operative complications and postoperative morbidity related to cranial neuropathies will be discussed. The rationale for performing adjunct procedures, including cricopharyngeal myotomy and vocal fold medialization, to facilitate the rehabilitation of patients with postoperative cranial nerve deficits will be given. Our findings and recommendations will be compared with currently accepted treatment protocols in conjunction with a review of the literature.

The pretectum mediates rapid eye movement sleep regulation by light.

A variety of sensory stimuli (e.g., visual, auditory, and thermal) are known to induce rapid eye movement (REM) sleep in mammals. Studies have examined the induction of REM sleep in albino rats by light-to-dark transitions, a phenomenon referred to as REM sleep triggering. Recent research has demonstrated that aspiration lesions of the superior colliculus (SC) and pretectal area attenuated REM sleep triggering. To define more specifically the area or areas involved in mediating REM sleep responses to changes in illumination, fiber-sparing neurotoxic lesions were made to the pretectum (PT) or the SC. Lesions of the PT attenuated REM sleep triggering, whereas lesions of the SC did not. Thus, the role of the PT may be expanded to include the regulation of REM sleep in response to photic stimulation in albino rats. These findings provide a paradigm in which to study mechanisms of REM sleep generation and the effects of light on behavioral state.

NO causes perinatal pulmonary vasodilation through K+-channel activation and intracellular Ca2+ release.

Evidence suggests that nitric oxide (NO) causes perinatal pulmonary vasodilation through K+-channel activation. We hypothesized that this effect worked through cGMP-dependent kinase-mediated activation of Ca2+-activated K+ channel that requires release of intracellular Ca2+ from a ryanodine-sensitive store. We studied the effects of 1) K+-channel blockade with tetraethylammonium, 4-aminopyridine, a voltage-dependent K+-channel blocker, or glibenclamide, an ATP-sensitive K+-channel blocker; 2) cyclic nucleotide-sensitive kinase blockade with either KT-5823, a guanylate-sensitive kinase blocker, or H-89, an adenylate-sensitive kinase blocker; and 3) blockade of intracellular Ca2+ release with ryanodine on NO-induced pulmonary vasodilation in acutely prepared late-gestation fetal lambs. N-nitro-L-arginine, a competitive inhibitor of endothelium-derived NO synthase, was infused into the left pulmonary artery, and tracheotomy was placed. The animals were ventilated with 100% oxygen for 20 min, followed by ventilation with 100% oxygen and inhaled NO at 20 parts/million (ppm) for 20 min. This represents the control period. In separate protocols, the animals received an intrapulmonary infusion of the different blockers and were ventilated as above. Tetraethylammonium (n = 6 animals) and KT-5823 (n = 4 animals) attenuated the response, whereas ryanodine (n = 5 animals) blocked NO-induced perinatal pulmonary vasodilation. 4-Aminopyridine (n = 5 animals), glibenclamide (n = 5 animals), and H-89 (n = 4 animals) did not affect NO-induced pulmonary vasodilation. We conclude that NO causes perinatal pulmonary vasodilation through cGMP-dependent kinase-mediated activation of Ca2+-activated K+ channels and release of Ca2+ from ryanodine-sensitive stores.

Willingness to treat HIV-positive patients at different stages of medical education and experience.

The willingness of physicians to provide care to HIV-positive patients has been linked to a number of attitudinal factors, but little is known concerning the impact of premedical, medical, and residency training on these factors. The purpose of this study is to elicit responses to the same series of questions concerning HIV and its treatment from respondents at different stages of training, to detect trends in attitudes and to measure the impact of those attitudes on willingness to provide care for HIV/AIDS patients. Study data come from a cross-sectional survey (n = 249) of respondents across the training continuum, from premedical students to faculty physicians, using a self-administered questionnaire at a single medical school. The response rate was 59.6%. The study showed significant decreases in personal fear and misgivings concerning HIV, coupled with a substantial decrease in the perceived need for testing of non-high-risk individuals, as respondents gained additional education and training. Overall, the intent to treat HIV did not change significantly by training level, but multivariate analyses showed that while the initially strong influence of attitudes toward AIDS and its attendant risks diminishes, comfort relative to being around homosexuals per se continues to exert an impact on the intent to treat. Appropriate use of protective measures when providing care becomes far more common once individuals enter their clinical training years. The impact of medical education through its entire continuum therefore shows a positive impact on attitudes toward HIV, despite the absence of a significant trend in respondents' stated intent to treat. However, negative attitudes toward homosexuals continue to exert a negative influence on intent to treat that endures into the clinical training years.

Regulation of SNARE complex assembly by an N-terminal domain of the t-SNARE Sso1p.

The fusion of intracellular transport vesicles with their target membranes requires the assembly of SNARE proteins anchored in the apposed membranes. Here we use recombinant cytoplasmic domains of the yeast SNAREs involved in Golgi to plasma membrane trafficking to examine this assembly process in vitro. Binary complexes form between the target membrane SNAREs Sso1p and Sec9p; these binary complexes can subsequently bind to the vesicle SNARE Snc2p to form ternary complexes. Binary and ternary complex assembly are accompanied by large increases in alpha-helical structure, indicating that folding and complex formation are linked. Surprisingly, we find that binary complex formation is extremely slow, with a second-order rate constant of approximately 3 M(-1) s(-1). An N-terminal regulatory domain of Sso1p accounts for slow assembly, since in its absence complexes assemble 2,000-fold more rapidly. Once binary complexes form, ternary complex formation is rapid and is not affected by the presence of the regulatory domain. Our results imply that proteins that accelerate SNARE assembly in vivo act by relieving inhibition by this regulatory domain.

The process of change in couples therapy: a qualitative investigation.

Open-ended interviews with 24 couples therapy clients regarding their experience of the process of change revealed shifts in clusters of affect, communication, and cognition. Six additional contextual preconditions for change were also identified. The change process within couples was uniformly reported to be gradual.

Recurrence of haemolytic-uraemic syndrome in renal transplants: a single-centre report.

BACKGROUND: The incidence of recurrence of haemolytic-uraemic syndrome (HUS) in renal allografts appears to vary by centre, with the highest rates reported from the University of Minnesota. It is possible that the high rate of HUS recurrence at this institution reflects a transplant population skewed towards patients with a form of HUS that is more likely to recur in the allograft. METHODS: This study examined whether the initial episode of HUS in the native kidneys was preceded by a diarrhoeal prodrome ('classical HUS') or not ('atypical HUS'), and evaluated transplant outcomes in 24 patients who received 36 transplants at the University of Minnesota between 31 May 1972 and 31 December 1994. RESULTS: Eighteen of the 24 patients had atypical HUS, three had classical HUS, and in three patients the presence or absence of a diarrhoeal prodrome could not be determined. Recurrent HUS, defined as microangiopathic haemolytic anaemia, thrombocytopenia, renal insufficiency, and allograft biopsy findings compatible with HUS, occurred 16 times in 14 grafts in 11 patients. Nine of these patients had atypical HUS, one had classical HUS, and in one the nature of the prodrome could not be determined. Eleven of the 14 initial recurrences took place within 2 months of transplant. Recurrence was not more frequent in patients who received cyclosporin or antilymphocyte preparations. Actuarial analysis using matched controls showed poorer graft survival in patients with a primary diagnosis of HUS (P = 0.007), due to the high frequency of graft loss in HUS patients with recurrence. CONCLUSION: Based upon these data and a review of the literature, it can be concluded that the risk of recurrence of HUS in the allograft is confined almost entirely to patients with atypical forms of HUS.

The effect of core translucency on the aesthetics of all-ceramic restorations.

Recent advances in ceramic technology have revolutionized aesthetic dentistry. When treating a single anterior tooth in need of a full-coverage restoration, a multitude of options in restorative materials and techniques is available to the clinician. The learning objective of this article is to present and evaluate a selection of all-ceramic dental materials currently available for aesthetic full-coverage crown restorations. When selecting an all-ceramic system, there are several major factors to consider, including the inherent translucency of the ceramic material and of the adjacent dentition, the color of the prepared tooth, and the forces anticipated in that region. Preparation and restoration of discolored and nondiscolored tooth structure are reviewed. The techniques presented can be utilized to obtain predictable results in the anterior region for aesthetic all-ceramic full-coverage restorations.

Effect of water content in perchloric acid on the non-aqueous potentiometric titration of nitrogen-containing compounds.

In the United States Pharmacopeia (USP), 0.1 N perchloric acid in acetic acid volumetric solution (hereafter HClO4 VS) used for non-aqueous titration has specified a water content between 0.02 and 0.05%. Preparing this titrant with such a narrow range of water content is very time consuming, precludes the use of commercially available titrants, and, consequently, prompted an investigation to try and expand the range up to 0.5%. In this study, the titrimetric results obtained using HClO4 VS containing more water were very close to those obtained using the USP specified titrants. A maximum assay difference of 0.7% in the titrations of three selected nitrogen-containing compounds, clonidine hydrochloride, dipyridamole, and adenosine were observed. The titrimetric results obtained using these titrants were also precise with RSDs of not more than 0.4%. Therefore, a wider range of water content in HClO4 VS between 0.02 and 0.5% is suggested for the USP potentiometric titration of nitrogen-containing compounds.

Respiratory syncytial virus infections in pediatric renal transplant recipients.

Immunocompromised patients are considered at increased risk from respiratory syncytial virus (RSV) infection. We examined the incidence and outcome of RSV infection in pediatric renal transplant (Tx) recipients on chronic immunosuppressive therapy. Of 173 recipients transplanted between November 1985 and April 1993, 5 (3%) developed RSV infection (age range 11-39 months). Initial immunosuppression included prednisone, azathioprine, cyclosporine, and polyclonal antibody therapy. Time from Tx to onset of RSV infection was 1 day to 7 months. Symptoms included rhinorrhea, cough, tachypnea, retractions, fever, wheezing, and abnormal chest X-ray. Treatment included bronchodilator therapy, bronchial drainage, ribavirin, and mist tent. Azathioprine was transiently withheld for leukopenia during treatment in 2 recipients. Three recipients developed biopsy-proven acute rejection during (n = 2) or immediately following (n = 1) RSV infection; all responded to corticosteroid treatment. RSV infection is not commonly diagnosed in pediatric renal Tx recipients. The course of RSV infection in our patients did not differ from that reported in normal children. The possible association between RSV and acute rejection warrants further observation. When diagnosed early, RSV infection does not appear to be associated with increased mortality in pediatric renal Tx recipients. Larger numbers of recipients need to be studied to confirm these results.