Clinical evaluation of six intraocular lens calculation formulas

We examined the results of posterior chamber intraocular lens (IOL) implantation and evaluated six commonly used IOL power calculation formulas (original Binkhorst, modified Binkhorst, Colenbrander, Shammas, Hoffer, and SRK regression) to determine which ones produce the most accurate and predictable results. We found that the accuracy of the various formulas depends upon several factors, including the surgeon's technique, the type and style of posterior chamber IOL implanted, and the axial length of the eye being operated on. Furthermore, we found that the results using the different formulas vary in a consistent pattern. Surgeons must therefore evaluate their cases periodically to determine which formulas and IOL styles will provide their patients with the most accurate and satisfying results.     

Thorotrast-associated hepatic leiomyosarcoma and cholangiocarcinoma in a single patient

A 66-year-old man developed two distinct primary malignant hepatic neoplasms (leiomyosarcoma and cholangiocarcinoma) 50 years after Thorotrast administration. This is the first case report of Thorotrast-associated primary hepatic leiomyosarcoma. Ultrastructural and immunohistochemical studies are discussed.     

Phylogenetic and Ecologic Perspectives of a Monkeypox Outbreak,Southern Sudan, 2005

Identification of human monkeypox cases during 2005 in southern Sudan (now South Sudan) raised several questions about the natural history of monkeypox virus (MPXV) in Africa. The outbreak area, characterized by seasonally dry riverine grasslands, is not identified as environmentally suitable for MPXV transmission. We examined possible origins of this outbreak by performing phylogenetic analysis of genome sequences of MPXV isolates from the outbreak in Sudan and from differing localities. We also compared the environmental suitability of study localities for monkeypox transmission. Phylogenetically, the viruses isolated from Sudan outbreak specimens belong to a clade identified in the Congo Basin. This finding, added to the political instability of the area during the time of the outbreak, supports the hypothesis of importation by infected animals or humans entering Sudan from the Congo Basin, and person-to-person transmission of virus, rather than transmission of indigenous virus from infected animals to humans.     

Rising incidence of type 1 diabetes in Scottish children, 1984-93. The Scottish Study Group for the Care of Young Diabetics

OBJECTIVES: To calculate the incidence of type 1 diabetes in Scottish children aged less than 15 years between 1984 and 1993; to examine changes in incidence; and to calculate the prevalence of diabetes at the end of this period. DESIGN: Three data sources were used to construct the Scottish Study Group for the Care of Young Diabetics register: active reporting of all new cases; reports from the Scottish Morbidity Register 1; and local registers. SUBJECTS: All children resident in Scotland diagnosed with primary insulin dependent diabetes mellitus when less than 15 years of age between 1984 and 1993. MAIN OUTCOME MEASURES: Annual incidence and prevalence rate for Scotland; time trend in incidence over the 10 years; differences in incidence between the three different age groups; and completeness of the register. RESULTS: The average annual incidence for Scotland was 23.9/100,000 children. The prevalence rate was 1.5/1000 in 1993. A total of 2326 cases was identified from the three sources. Capture-recapture analysis suggests a case ascertainment of 98.6%. The annual incidence rates increased at a rate of 2% each year (rate ratio = 1.02, 95% confidence interval (CI) 1.01 to 1.03). The incidence was higher in boys than girls (rate ratio = 1.08, 95% CI 1.00 to 1.18), and the incidence rates increased with age: 15.3/100,000/year for age 0-4 years, 24.4/ 100,000/year for age 5-9 years, and 31.9/ 100,000/year for age 10-14 years. CONCLUSIONS: The incidence of type 1 diabetes in Scotland is increasing and the prevalence is relatively high. These findings have important implications for health service resource allocation. The Scottish Study Group for the Care of Young Diabetics' register provides a base for monitoring and research.     

Overdependence on degraded gist memory in Alzheimer's disease

Alzheimer's disease (AD) reduces associative effects on false recognition in the Deese-Roediger-McDermott task, either due to impaired memory for gist or impaired use of gist in memory decisions. Gist processes were manipulated by blocking or mixing studied words according to their associations and by varying the associative strength between studied and nonstudied words at test. Both associative blocking and associative strength had smaller effects on false recognition in AD patients than in control participants, consistent with gist memory impairments. However, unlike the case with control participants, blocking influenced true and false recognition equally in AD patients, demonstrating an overdependence on gist when making memory decisions. AD also impaired item-specific recollections, relative to control participants, as true recognition of studied words was reduced even when the two groups were equated on gist-based false recognition. We propose that the overdependence on degraded gist memory in AD is caused by even larger impairments in item-specific recollections.     

Interventional radiologic procedures in the renal transplant

Percutaneous interventional procedures can be valuable in the evaluation and treatment of urologic complications of renal transplantation. Thirty-three patients underwent percutaneous procedures, including relief of obstruction by catheter nephrostomy, diagnostic antegrade pyelography with Whitaker testing, aspiration of various fluid collections (lymphocele, hematoma, urinoma, and abscess), and renal artery angioplasty, during a three year period at three institutions, to provide temporizing treatment and anatomic data. Surgical intervention was sometimes avoided, but more often it could be deferred to allow the patient to stabilize prior to surgery. Complications that required surgery occurred in two patients.     

Survival of adult 5-HT neurons following intraocular transplantation

The present study was undertaken to provide an improved environment in which to examine the capacity of more mature CNS tissue to survive following transplantation. Tissue containing serotonin (5-HT) neurons from nucleus raphe dorsalis of 4- and 8-week-old rats was transplanted to the anterior chamber of the eye. Baseline conditions were improved by minimizing the time of the grafting procedure and enhancing the nutrition and oxygenation of the grafting medium. Additional treatment of the grafts during the 4 weeks of in oculo development included either: (1) intermittent hyperbaric oxygen (HBO), (2) continuous hyperoxia, or (3) control. In vivo measurement revealed that all grafts decreased significantly in size, a majority of which still demonstrated a small degree of vascularization. Microscopically, a significant percentage of the grafts demonstrated 5-HT-immunoreactive (5-HT-ir) fiber outgrowth into the host irides, although 5-HT-ir cell bodies could not always be discerned. In terms of percentage of grafts with surviving 5-HT-ir fibers, the best results were seen with the grafts treated with continuous hyperoxia (3 out of 4), as compared to HBO-treated grafts (4/18) and the control group (3/24). For both the HBO-treated and control groups, slightly better results were seen with 4-week-old vs 8-week-old donor tissue. The density and the surface area covered by the 5-HT-ir fibers was not correlated with either treatment or donor age. Thus, while continuous hyperoxia or HBO treatment may have a positive effect, the enhanced baseline conditions appear to provide an environment in which to demonstrate that 5-HT neurons from 4- and 8-week-old rats possess the capacity to survive transplantation.     

Decreased level of nerve growth factor (NGF) and its messenger RNA in the aged rat brain

Trophic factors such as nerve growth factor (NGF) are thought to support survival, differentiation and maintenance of neurons. Recent results indicate that NGF produced in cortical and hippocampal areas is required for the function of cholinergic neurons in the basal forebrain. With the use of enzyme immunoassay and RNA blot hybridization we studied the NGF protein and NGF mRNA, respectively, in regions of the brain innervated by basal forebrain cholinergic neurons in adult and aged rats. Levels of NGF protein were decreased by 40% in hippocampus of aged (28 months) Fischer 344 rats compared with adults (6 months), whereas no alterations were observed in cerebral cortex. Moreover, a reduction by 50% in the NGF mRNA was found in samples of the aged forebrain (cerebral cortex, hippocampus, basal forebrain and hypothalamus) compared to the adult. NGF deficiencies may thus account for the loss of cholinergic neurons in the basal forebrain generally found to accompany normal aging and resulting in altered cognitive functions.