A prototype retractor system designed to minimize ischemic brain retractor injury: initial observations

The authors have developed and patented a neurosurgical retractor system incorporating an infrared emitter and detector that allows detection of cerebral pulsations. Gentle contact with the surface of cat brains shows cerebral pulsations that correlate with arterial pulse as well as mechanical ventilation. The amplitude of cerebral pulsations decreases with higher retraction pressure and disappears at approximately 20 mmHg. The pressure on the surface of the brain decreased 50% in 5 minutes even though the position of the retractor was maintained constant. The authors postulate that monitoring cerebral pulsation may prove useful in clinical neurosurgery with respect to avoiding excessive retraction, which causes brain damage.     

Non-ulcerative fungal keratitis diagnosed by posterior lamellar biopsy*

We report a case of Fusarium solani keratitis which highlights the difficulties often associated with management of fungal corneal infections. This case demonstrates several unusual and interesting features: the occurrence of deep fungal pathology after superficial injury, the difficulties encountered in attempting to isolate and identify the causative organism, and the protracted course taken by an organism often noted to be rapidly destructive. These features necessitated an individual approach to therapy, employing unconventional medical and surgical techniques to achieve a satisfactory outcome     

An optimal three-stage design for phase II clinical trials

A phase II clinical trial in cancer therapeutics is usually a single-arm study to determine whether an experimental treatment (E) holds sufficient promise to warrant further testing. When the criterion of treatment efficacy is a binary endpoint (response/no response) with probability of response p, we propose a three-stage optimal design for testing H₀: p ≤ p₀ versus H₁: p ≥ p₁, where p₁ and p₀ are response rates such that E does or does not merit further testing at given levels of statistical significance (α) and power (1 ? β). The proposed design is essentially a combination of earlier proposals by Gehan and Simon. The design stops with rejection of H₁ at stage 1 when there is an initial moderately long run of consecutive treatment failures; otherwise there is continuation to stage 2 and (possibly) stage 3 which have decision rules analogous to those in stages 1 and 2 of Simon's design. Thus, rejection of H₁ is possible at any stage, but acceptance only at the final stage. The design is optimal in the sense that expected sample size is minimized when p = p₀, subject to the practical constraint that the minimum stage 1 sample size is at least 5. The proposed design has greatest utility when the true response rate of E is small, it is desirable to stop early if there is a moderately long run of early treatment failures, and it is practical to implement a three-stage design. Compared to Simon's optimal two-stage design, the optimal three-stage design has the following features: stage 1 is the same size or smaller and has the possibility of stopping earlier when 0 successes are observed; the expected sample size under the null hypothesis is smaller; stages 1 and 2 generally have more patients than stage 1 of the two-stage design, but a higher probability of early termination under H₀; and the total sample size and criteria for rejection of H₁ at stage 3 are similar to the corresponding values at the end of stage 2 in the two-stage optimal design.     

Familias Unidas: The Efficacy of an Intervention to Promote Parental Investment in Hispanic Immigrant Families

This paper reports a test of the efficacy of Familias Unidas, a Hispanic-specific, ecologically focused, parent-centered preventive intervention, in promoting protection against and reducing risk for adolescent behavior problems. Specifically, the intervention was designed to foster parental investment, reduce adolescent behavior problems, and promote adolescent school bonding/academic achievement, all protective factors against drug abuse and delinquency. One-hundred sixty seven Hispanic families of 6th and 7th grade students from three South Florida public schools were stratified by grade within school and randomly assigned to intervention and no-intervention control conditions. Results indicated that Familias Unidas was efficacious in increasing parental investment and decreasing adolescent behavior problems, but that it did not significantly impact adolescent school bonding/academic achievement. Summer-vacation rates of adolescent behavior problems were six times higher in the control condition than in the intervention condition. Furthermore, change in parental investment during the intervention was predictive of subsequent levels of adolescent behavior problems. The findings suggest that Familias Unidas is efficacious in promoting protection and reducing risk for adolescent problem behaviors in poor immigrant Hispanic families.     

Dipyridamole technetium 99m sestamibi myocardial tomography as an independent predictor of cardiac event-free survival after acute ischemic events

Background  

A total of 137 consecutive patients with recent uncomplicated myocardial infarction (n=31) or unstable angina (n=106) were studied to determine the relative prognostic value of predischarge clinical risk stratification and intravenous dipyridamole stress sestamibi (MIBI) myocardial tomography in patients unable to exercise maximally after an acute ischemic coronary event.     

Abdominoperineal resection for adenocarcinoma of the low rectum

Current understanding of the routes of spread of rectal cancer along with technical innovations such as the circular stapler have allowed surgeons to treat most rectal cancers with an anterior resection and low anastomosis. Appropriate use of local therapy options has further decreased the need for abdominoperineal resection (APR). Nonetheless, APR remains the procedure of choice for many distal rectal adenocarcinomas. Numerous factors influence the decision to perform an APR and are discussed in detail. Although mortality for APR has been reduced significantly, morbidity remains high. Specific complications commonly seen after APR are discussed. Operative technique is outlined since much of the specific morbidity of APR can be reduced by attention to detail in the conduct of this complex procedure.

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Resumen El conocimiente actual de las rutas de extensión del cáncer rectal junto con innovaciones técnicas tales como el suturador circular han permitido a los cirujanos tratar la mayoría de los cánceres rectales mediante la resección anterior con anastomosis baja. El uso apropiado de opciones de tratamiento local ha disminuido aún más la necesidad de practicar la resección abdominoperineal (RAP). Sin embargo, la RAP sigue siendo el procedimiento de escogencia para muchos adenocarcinomas del recto distal. Son numerosos los factores que influyen sobre la decisión de realizar una RAP y éstos son motivo de discusión detallada en el presente artículo. Aunque la mortalidad asociada con la RAP se ha reducido significativamente, la morbilidad se mantiene elevada. Se revisan las complicaciones específicas más comunes después de la RAP. Se detalla la técnica quirúrgica, puesto que mucha de la morbilidad específica de la RAP puede ser disminuida si se presta especial atención al detalle en la ejecución de este complejo procedimiento.

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Résumé La connaissance récente des voies de dissémination lymphatique du cancer du rectum ainsi que les innovations techniques comme la machine à agraphage mécanique ont permis de traiter la plupart des tumeurs rectales par une résection antérieure et une anastomose basse. L'utilisation de la radiothérapie locale a diminué encore les indications d'amputations abdomino-périneales. Néanmoins, l'amputation reste l'indication de choix dans beaucoup de cancers rectaux distaux; les facteurs qui interviennent dans ce choix sont discutés. Bien que la mortalité des amputations abdomino-périneales ait beaucoup diminuée, la morbidité reste élevée. Les complications spécifiques de l'amputation sont exposées. La technique opératoire est exposée parce que la morbidité peut être souvent réduite lorsque le chirurgien fait attention à tous les détails au cours de cette intervention complexe.

     

Salmon farming: occupational health in a new rural industry

The medical hazards of salmon farming can be grouped into thoserelated to marine safety, fish husbandry, fish-farm diving anddisease treatments. The hostile water environment requires thermalprotection and personal buoyancy aids as workers frequentlyfall in the water from boats or cages. Feedstuffs may generaterespirable dust and attract rats, creating a risk of leptospirosis.Musculo-skeletal injuries are common from lifting nets. Fish-farmdiving has particular risks which can be minimized. Organophosphorouspesticides are used to treat sea lice and employees requirehealth surveillance. Fish immunization is required to reducethe incidence of Aeromonas salmonitica. Needlestick injurieswhen using oil-based vaccines are a serious hazard to employees.The occupational health problems of salmon farming are predictableand preventable with primary safety measures. This new industryis safer than land-based agriculture on current evidence.     

Cholecystokinin and neuropeptide Y receptors on single rabbit vagal afferent ganglion neurons: site of prejunctional modulation of visceral sensory neurons

A [¹²⁵I]cholecystokinin (CCK) analog and [¹²⁵I]peptide YY (PYY) were used to localize and characterize CCK and neuropeptide Y (NPY) receptor binding sites in the rabbit vagal afferent (nodose) ganglion. High concentrations of CCK and NPY binding sites were observed in 10.6% and 9.2% of the nodose ganglion neurons, respectively. Pharmacological experiments using CCK or NPY analogs suggest that both subtypes of CCK (CCK-A and CCK-B) and NPY (Y1 and Y2) receptor binding sites are expressed by discrete populations of neurons in the nodose ganglion. These results suggest sites at which CCK or NPY, released in either the nucleus of the solitary tract or a peripheral tissue, may modulate the release of neurotransmitters from a select population of visceral primary afferent neurons. Possible functions mediated by these receptors include modulation of satiety, opiate analgesia, and the development of morphine tolerance.