Computer and robotic assisted osteotomy around the knee.

The outcome variability and failures of conventional osteotomy have been attributed to lack of preoperative planning and inaccuracy in performing the correction. We present a computer and robotic assisted surgery system that can aid in accurate surgical planning for realignment, and in precisely implementing the plan in theatre. The approach seeks to avoid the cost and risks associated with the use of CT, and the insertion of fiducial markers, which are characteristic of existing computer assisted surgical systems. The paper details the architecture of the system as a whole, placing particular emphasis on planning technique. It is anticipated that the increased accuracy possible with the system will prove particularly useful for correcting multi-plane deformities, which are more problematic with conventional techniques.

Dementia in stroke survivors in the Stroke Data Bank cohort. Prevalence, incidence, risk factors, and computed tomographic findings.

We determined the prevalence of dementia in 927 patients with acute ischemic stroke aged greater than or equal to 60 years in the Stroke Data Bank cohort based on the examining neurologist's best judgment. Diagnostic agreement among examiners was 68% (kappa = 0.34). Of 726 testable patients, 116 (16%) were demented. Prevalence of dementia was related to age but not to sex, race, handedness, educational level, or employment status before the stroke. Previous stroke and previous myocardial infarction were related to prevalence of dementia although hypertension, diabetes mellitus, atrial fibrillation, and previous use of antithrombotic drugs were not. Prevalence of dementia was most frequent in patients with infarcts due to large-artery atherosclerosis and in those with infarcts of unknown cause. Computed tomographic findings related to prevalence of dementia included infarct number, infarct site, and cortical atrophy. Among 610 patients who were not demented at stroke onset, we used methods of survival analysis to determine the incidence of dementia occurring during the 2-year follow-up. Incidence of dementia was related to age but not sex. Based on logistic regression analysis, the probability of new-onset dementia at 1 year was 5.4% for a patient aged 60 years and 10.4% for a patient aged 90 years. With a multivariate proportional hazards model, the most important predictors of incidence of dementia were a previous stroke and the presence of cortical atrophy at stroke onset.

Alpha 1-acid glycoprotein in the neonate with and without infection.

In a study of early neonatal infection, 278 babies had a blood culture and an alpha 1-acid glycoprotein (alpha 1-AGP) determination. There were significant differences between the mean (+/- SEM) levels of alpha 1-AGP in infants who were noninfected (26 +/- 1.3 mg/dl, n = 244), infected (81 +/- 11 mg/dl, n = 12) and proved to have sepsis (66 +/- 10 mg/dl, n = 22). In the 'noninfected' group, alpha 1-AGP levels increased with postnatal age. Increasing levels were seen on the 1st day with both increasing gestational age (15-34 mg/dl from less than 30 to greater than or equal to 38 weeks) and birth weight (17-42 mg/dl from less than 1,000 to greater than or equal to 4,000 g), irrespective of the infant's sex. Among the sepsis group, infants who died had lower levels than those who survived (19 mg/dl vs. 90 mg/dl).

Early diagnosis of neonatal sepsis.

To better define the need for antibiotic therapy, several tests recommended as helpful in diagnosing neonatal sepsis were evaluated in 376 neonates during the first week after birth. The five most useful tests (with definitions of abnormality) were: band/total neutrophils (greater than or equal to 0.2); leukocyte count (less than 5,000/cu mm); latex-C-reactive protein (positive greater than 0.8 mg/100 ml); ESR (greater than or equal to 15 mm for the first hour); and latex haptoglobin (positive greater than 25 mg/100 ml). When these five tests were applied early (at the time infection was suspected and blood culture sent), 28 of 30 cases (93%) subsequently proven to have infection had two or more abnormal tests. This compares with only 24 of 320 babies (8%) with no subsequently documented evidence of infection. Of all babies who had two or more tests positive (n = 71), 39% had proven sepsis, and an additional 23% had "very probable" infection. The combination of leukopenia and an elevated band/total neutrophil ratio seems to be particularly predictive of sepsis (13 of 17 babies with this combination had proven sepsis). When less than two tests were positive, the probability that sepsis was not present was 99%. These simple, rapid tests require no special laboratory facilities and provide a valuable adjunct in the early detection of the neonate with sepsis.

The effects of dexamethasone and prostaglandin F2alpha on production and release of surfactant in type II alveolar cells.

Incubation of adult rat Type II alveolar pneumocytes with dexamethasone microM induced an increase of intracellular 3Hphosphatidyl choline (PC), a component of lung surfactant, from precursor 3Hcholine. Release of 3HPC into the media did not differ from control unless prostaglandin F2alpha-THAM microM was added to the dexamethasone-treated cells. This observation corresponds to the ontogenetically observed endogenous increases in cortisol during pregnancy followed by increases in prostaglandins associated with contractions. The model system will serve well to test whether various substances effect synthesis and/or release of pulmonary surfactants.