Pars plana vitrectomy and direct diathermy for complications of multiple retinal angiomas.

A 16-year-old female had multiple retinal capillary angiomas, complicated by marked retinal and optic disc neovascularization, preretinal membranes, and retinal detachment in her right eye. Pars plana lensectomy, vitrectomy, fluid/gas exchange, direct transvitreal diathermy of the angiomas, endolaser scatter photocoagulation, and scleral buckling resulted in retinal reattachment and regression of the neovascularization. Although additional surgery was necessary for recurrent tractional retinal detachment, long-term retinal reattachment and stable vision was achieved following obliteration of all angiomas.     

Using serial observations to identify predictors of progression to AIDS in the Toronto Sexual Contact Study.

The Toronto Sexual Contact Study comprises a cohort of 249 male sexual contacts of men with HIV disease which has been followed every 3 months for almost 5 years. On enrollment 143 were seropositive and 16 seroconverted during the follow-up period. By 31 December 1989, 41 of the 159 seropositive cohort members had developed AIDS. Using Cox relative risk regression models, we investigated the association of a number of laboratory and clinical variables and progression to AIDS. Fixed covariate models examined laboratory variables from the enrollment visit of cohort members, with time calculated from this date. In models assessing time dependent covariates, time was calculated from the estimated date of HIV infection. In the univariate models of either fixed or time dependent covariates, many variables were significantly associated with risk of progression to AIDS (T4 cell count, T4/T8 ratio, blastogenic responses to phytohemagglutinin, concanavalin A, and pokeweed mitogen, serum IgA, appearance of p24 antigen, and the development of oral hairy leukoplakia, thrush, or herpes zoster). Appearance of persistent generalized lymphadenopathy was not associated with increased risk of progression. In the multivariate model which evaluated fixed laboratory covariates, T4/T8 ratio, IgA level, and PHA response at enrollment were significantly associated with elevated risk.(ABSTRACT TRUNCATED AT 250 WORDS)     

Rejuvenation in the early 20th century

Summary. The first theoretical reflections concerning the relation of hormone production with the ageing process stemmed from Charles Edouard Brown-Sequard (1817–1894). At the age of 72 years he experimented on himself with an injection of animal testicular extract.
The Viennese physiologist Eugen Steinach (1861–1944) gained world-wide acknowledgement for his theory of 'autoplastic' treatment of ageing. He deduced that after vasoligation, an increased incretory hormonal production would ensue following the cessation of the secretory output of the gonads. The first operation was performed in 1918 and resulted in a vasectomy boom over the next two decades.
The Russian Serge Voronoff (1866–1951), working in Paris, was one of the first to transplant testicular tissue from a monkey into a human reproductive gland in 1920. Five years later he had already performed this procedure on 300 patients and attracted patients from all over the world.
In America early efforts of human testicular transplantation were performed by Frank Lydston and V.D. Lespinasse. Steinach's vasoligation was taken over by many American doctors, e.g., Harry Benjamin and Charles H. Chetwood. Among the patients who underwent a rejuvenation operation according to Steinach's method were Sigmund Freud (1856–1939) and the Irish poet and Nobel Prize winner William Butler Yeats (1865–1939). Two caricatures from the German magazine Simplicissimus published in 1927, confirm that the rejuvenation operations were constantly in the limelight of the printed media. From 1935 onwards rejuvenation operations gradually lost their appeal due to the introduction of artificial androgens.     

Milk nasendoscopy in the assessment of dysphagia.

The bedside assessment of dysphagia may be difficult, due to the inability to witness the act of swallowing directly. The milk test described in this paper gives a good assessment of swallowing, is cheap and easily portable and allows an instant decision to be made without recourse to special investigations.     

In vivo biological validation and biophysical modeling of the sensitivity and positive accuracy of endocrine peak detection. II. The follicle-stimulating hormone pulse signal

Despite interest in the in vivo control of gonadotropin release, valid assessment of the physiological regulation of the pulsatile secretion of the gonadotropin FSH has been hampered by the uncertain validity and reliability of available FSH peak detection algorithms. Difficulties in identifying FSH peaks accurately are believed to arise in part because of the slow metabolic clearance of this glycoprotein hormone. Here, we have used two complementary strategies to test the validity of FSH pulse detection. First, by means of a computer-assisted mathematical model for simulating episodic hormone secretion, we evaluated the effects of various putative FSH secretory pulse amplitudes and half-lives on the sensitivity and positive accuracy of peak detection. Secondly, we used an in vivo primate animal model, in which presumptively true FSH pulses were evaluated independently by continuous electrophysiological monitoring of mediobasal hypothalamic multiunit activity. These two approaches allowed us to define optimal pulse analysis parameters that yield maximal sensitivity and positive accuracy for detecting FSH peaks in synthetic and biological time series. We found (as predicted intuitively) that increasing half-times of hormone disappearance decrease both the sensitivity and positive accuracy of peak detection for any given peak detection thresholds and hormone secretory amplitudes. However, adequately sampled episodic FSH time series could be analyzed for FSH pulsatility by an appropriately constrained, objective computerized algorithm with reasonable (less than 10-15%) false negative and false positive errors, such that resultant sensitivity and positive accuracy exceed 85-90%. Of interest, computer simulations and the in vivo animal model exhibited similar discriminative capabilities. We conclude that increasing half-times of hormone (e.g. FSH) removal do impair hormone peak detection sensitivity and positive accuracy. Nevertheless, gonadotropin time series can be analyzed for FSH pulsatility in a valid manner with adequately constrained false negative and false positive error rates.     

Behavioral risk factors for injury among rural adolescents.

This 3-year, longitudinal, prospective study examined behavioral risk factors for medically attended injuries among a cohort of 758 rural students from Maryland's Eastern Shore region who were 12-14 years of age in 1987. Students were surveyed annually in the eighth, ninth, and tenth grades with a self-administered questionnaire. Information was obtained on the number of injuries experienced, risk-taking behaviors, delinquency, alcohol and drug use, physical exercise and sports, parental supervision, and work experience. Information on the parents' education was obtained from a parental interview. Slightly more than half (53.5%) of the students reported having experienced one or more injuries in the eighth grade as compared with one-third of the students in ninth grade, and 38% of those in the tenth grade. Poisson regression analyses were conducted to examine the association of eighth grade variables with ninth grade injuries and ninth grade variables with tenth grade injuries. Results from these analyses indicated that, in addition to sex and race, a high degree of risk taking, frequent cruising, and having high and low parental supervision in the eighth grade significantly increased the number of injuries in ninth grade. In the tenth grade, risk taking continued to be associated with injuries. In addition, students who reported disciplinary problems in school, working 1-10 hours per week, drinking on 1-2 days during the past month, lifetime use of marijuana equal to 1-5 occasions, and involvement in sports experienced greater numbers of injuries in the tenth grade.     

Turbulent stress measurements downstream of three bileaflet heart valve designs in pigs

Objective: Mechanical heart valves can cause thromboembolic complications, possibly due to abnormal flow patterns that produce turbulence downstream of the valve. The objective of this study was to investigate whether three different bileaflet valve designs would exhibit clinically relevant differences in downstream turbulent stresses. Methods: Three bileaflet mechanical heart valves (Medtronic Advantage^®, CarboMedics© Orbis™ Universal and St. Jude Medical^® Standard) were implanted into 19 female 90 kg pigs. Blood velocity was measured during open chest conditions in the cross sectional area downstream of the valves with 10 MHz ultrasonic probes connected to a modified Alfred^® Pulsed Doppler equipment. As a measure of turbulence, Reynolds normal stress (RNS) was calculated at three different cardiac output ranges (3–4, 4.5–5.5, 6–7 L/min). Results: Data from 12 animals were obtained. RNS correlated with increasing cardiac outputs. The highest instantaneous RNS observed in these experiments was 47 N/m², and the mean RNS taken spatially over the cross sectional area of the aorta during systole was between 3 N/m² and 15 N/m². In none of the cardiac output ranges RNS values exceeded the lower critical limit for erythrocyte or thrombocyte damage for any of the valve designs. Conclusions: Reynolds normal stress values were below 100 N/m² for all three valve designs and the difference in design was not reflected in generation of turbulence. Hence, it is unlikely that any of the valve designs causes flow induced damage to platelets or erythrocytes.     

Anosognosia in mild cognitive impairment: Relationship to activation of cortical midline structures involved in self-appraisal.

Awareness of cognitive dysfunction shown by individuals with Mild Cognitive Impairment (MCI), a condition conferring risk for Alzheimer's disease (AD), is variable. Anosognosia, or unawareness of loss of function, is beginning to be recognized as an important clinical symptom of MCI. However, little is known about the brain substrates underlying this symptom. We hypothesized that MCI participants' activation of cortical midline structures (CMS) during self-appraisal would covary with level of insight into cognitive difficulties (indexed by a discrepancy score between patient and informant ratings of cognitive decline in each MCI participant). To address this hypothesis, we first compared 16 MCI participants and 16 age-matched controls, examining brain regions showing conjoint or differential BOLD response during self-appraisal. Second, we used regression to investigate the relationship between awareness of deficit in MCI and BOLD activity during self-appraisal, controlling for extent of memory impairment. Between-group comparisons indicated that MCI participants show subtly attenuated CMS activity during self-appraisal. Regression analysis revealed a highly significant relationship between BOLD response during self-appraisal and self-awareness of deficit in MCI. This finding highlights the level of anosognosia in MCI as an important predictor of response to self-appraisal in cortical midline structures, brain regions vulnerable to changes in early AD.     

Non-invasive cardiac output monitoring.

Outcomes in the management of critically ill patients may be improved using goal-directed peri-operative haemodynamic monitoring. A conservative approach may no longer be acceptable but in view of the significant morbidity associated with balloon tipped flow directed pulmonary artery catheters a non-invasive approach would be preferable. In this review we consider the different non-invasive techniques available and discuss the advantages and disadvantages of each technique.