Preventing congestive heart failure

The morbidity, mortality and health care costs associated with congestive heart failure make prevention a more attractive public health strategy than treatment. Aggressive management of etiologic factors, including hypertension, coronary artery disease, valvular disease and excessive alcohol intake, can prevent the left ventricular remodeling and dysfunction that lead to heart failure. Early intervention with angiotensin converting enzyme inhibitors in patients with chronic left ventricular dysfunction can prevent, as well as treat, the syndrome. Several intervention strategies in patients with acute myocardial infarction can slow or prevent the left ventricular remodeling process that antedates congestive heart failure. The primary care physician must be alert to the need for aggressive intervention to reduce the burden of heart failure syndrome on the patient and on society.     

A directed shrinkage approach to the provision of foundations for decimated teeth

The directed shrinkage approach was developed to create sealed tooth-restoration interfaces in posterior composite restorations. Creative application of this technique can result in foundations that are suitable for a variety of applications, including salvaging broken-down teeth and supporting free-hand restorations. The sealed interface reduces microleakage and postoperative tooth sensitivity. The components required for this technique are readily available and are usually part of the practice's armamentarium.     

Long-term follow-up on hydroxylapatite-coated cylindrical dental implants: a comparison between developmental and recent periods

PURPOSE: To compare success rates for dental implants placed from 1985 through 1988 and from 1989 through 1991, and to investigate the factors associated with success or failure. PATIENTS AND METHODS: All hydroxylapatite-coated cylindrical implants placed from 1985 through 1991 were followed yearly. Lifetable survival analyses compared implant success for a "developmental period" from 1985 through 1988 (4 to 8 years follow-up) and a "recent period" from 1989 through 1991 (1 to 4 years follow-up). Reasons for success or failure, time from implant placement to removal related to failure reason, outcome after implant removal, and a morbidity analysis are included. RESULTS: The 7 to 8-year cumulative success rate for all implants placed in the developmental period (maxilla and mandible combined) was 86.5%; it was 84.2% for all maxillary implants and 87.5% for all mandibular implants. The cumulative success rate for all implants placed in the recent period was 97.5%; it was 97.5% for all maxillary implants and 97.6% for all mandibular implants. The difference between the two periods was statistically significant only for the anterior maxilla. Regression analysis on the interval success rates indicates that interval failure did not follow a linear relationship with time. The most common reasons associated with failure were lack of keratinized gingiva, poor oral hygiene, mechanical overload, and malposition. CONCLUSION: Comparison with previously reported cumulative success rates indicated learning curve experiences comparable with other implant systems. Improvements in hardware, surgical and prosthetic techniques, and patient selection have led to an improvement in success rates with the recent period implants.     

What is "special" about face perception?

There is growing evidence that face recognition is "special" but less certainty concerning the way in which it is special. The authors review and compare previous proposals and their own more recent hypothesis, that faces are recognized "holistically" (i.e., using relatively less part decomposition than other types of objects). This hypothesis, which can account for a variety of data from experiments on face memory, was tested with 4 new experiments on face perception. A selective attention paradigm and a masking paradigm were used to compare the perception of faces with the perception of inverted faces, words, and houses. Evidence was found of relatively less part-based shape representation for faces. The literatures on machine vision and single unit recording in monkey temporal cortex are also reviewed for converging evidence on face representation. The neuropsychological literature is reviewed for-evidence on the question of whether face representation differs in degree or kind from the representation of other types of objects.     

In vitro processing of herpes simplex virus type 1 DNA replication intermediates by the viral alkaline nuclease, UL12

Herpes simplex virus type 1 (HSV-1) DNA replication intermediates exist in a complex nonlinear structure that does not migrate into a pulsed-field gel. Genetic evidence suggests that the product of the UL12 gene, termed alkaline nuclease, plays a role in processing replication intermediates (R. Martinez, R. T. Sarisky, P. C. Weber, and S. K. Weller, J. Virol. 70:2075-2085, 1996). In this study we have tested the hypothesis that alkaline nuclease acts as a structure-specific resolvase. Cruciform structures generated with oligonucleotides were treated with purified alkaline nuclease; however, instead of being resolved into linear duplexes as would be expected of a resolvase activity, the artificial cruciforms were degraded. DNA replication intermediates were isolated from the well of a pulsed-field gel ("well DNA") and treated with purified HSV-1 alkaline nuclease. Although alkaline nuclease can degrade virion DNA to completion, digestion of well DNA results in a smaller-than-unit-length product that migrates as a heterogeneous smear; this product is resistant to further digestion by alkaline nuclease. The smaller-than-unit-length products are representative of the entire HSV genome, indicating that alkaline nuclease is not inhibited at specific sequences. To further probe the structure of replicating DNA, well DNA was treated with various known nucleases; our results indicate that replicating DNA apparently contains no accessible double-stranded ends but does contain nicks and gaps. Our data suggest that UL12 functions at nicks and gaps in replicating DNA to correctly repair or process the replicating genome into a form suitable for encapsidation.     

Laparoscopic versus open appendectomy

BACKGROUND: Clinical manifestations and course of sickle-cell anemia are variable. Knowledge about the factors, possibly geographic, that influence prognosis are still scanty. POPULATION AND METHODS: Data of hospitalization and management of children with sickle-cell disease were studied during two years (1992-1993) in the Pediatric Unit of Libreville Hospital. They concerned 205 admissions of 171 children and 131 outpatients. RESULTS: The main causes of hospitalization were: acute anemia (36 cases before the age of 5 years); painful crisis whose frequency increased with age (23% before 5 years, 35% between 5 and 10, 42% after 10 years); infections, essentially pulmonary occurring early, and bone infections at any age. Eight children died (because a complication of their disease). Among the 131 outpatients, half were detected because pyrexia, anemia and/or more often "hand-foot syndrome". More than 60% had hepatomegaly, one third still had splenomegaly after five years of age and more than one third was icteric. More than half children older than ten years had growth disorders. Mean hemoglobin level was 7 g/dL. 21 of the 83 tested children for HBsAg were positive and only one out of 79 was positive for HIV. CONCLUSIONS: Clinical manifestations and course of sickle-cell anemia in our patients are similar to those reported in Congolese children. Genetic and environmental factors may be responsible for differences with children from other, in particular French, cohorts.     

Automatic measurement of arterial pressure

PURPOSE: To identify patients with lymphoma at risk for tumor lysis after chemotherapy. PATIENTS AND METHODS: The case records of 102 patients receiving combination chemotherapy for non-Hodgkin's lymphoma (intermediate to high-grade histology) were reviewed. Patients were considered to have "laboratory tumor lysis" if two of the following metabolic changes occurred within 4 days of treatment: a 25% increase in the serum phosphate, potassium, uric acid, or urea nitrogen concentrations, or a 25% decline in the serum calcium concentration. "Clinical tumor lysis" was defined as laboratory tumor lysis plus one of the following: a serum potassium level greater than 6 mmol/L, a creatinine level greater than 221 mumol/L, or a calcium level less than 1.5 mmol/L, the development of a life-threatening arrhythmia, or sudden death. RESULTS: Laboratory tumor lysis occurred in 42% of patients and clinical tumor lysis in 6%. There was no statistical difference in the frequency of either tumor lysis syndrome among lymphoma subgroups. Clinical tumor lysis occurred more frequently in patients with pretreatment renal insufficiency (serum creatinine level greater than 132 mumol/L) than in patients with normal renal function (36% versus 2%; p = 0.01). The development of azotemia correlated with high pretreatment serum lactate dehydrogenase concentrations (p < 0.01; r2 = 0.11). CONCLUSION: Clinically significant tumor lysis is a rare occurrence in patients with lymphoma when they are receiving allopurinol. However, tumor lysis can occur in patients with all types of moderate to high-grade non-Hodgkin's lymphoma. Patients with a high serum lactate dehydrogenase level or renal insufficiency are at increased risk for metabolic complications after chemotherapy and should be closely monitored.     

Complications of surgery for discogenic disease of the spine

Disc disease is benign and not life threatening. Its long-term prognosis is uncertain, and spontaneous recoveries are common. The decision to perform surgery thus carries with it a heavy responsibility to provide safe treatment. "Good safe surgical technique" is essential, but it is much more than a well-rehearsed routine procedure. From preoperative evaluation to surgery to postoperative care, the surgeon must look ahead to problems that might arise. Where anticipated risks cannot be avoided, they should be minimized, and when adverse events occur, active recognition will lead to early and accurate management.