Survey of glaucoma in an eye clinic in Ghana,West Africa

PURPOSE: To report the various types of glaucoma among West African patients presenting to an eye clinic in Ghana. METHODS: A complete evaluation was performed in 198 consecutive Ghanaian glaucoma patients. Main outcome measures included intraocular pressure, visual acuity, gonioscopy findings, visual field, and total number of glaucoma medications. RESULTS: The most common form of glaucoma was primary open-angle glaucoma (44.2%). Open-angle glaucoma suspects also comprised a large percentage of the group (30.5%). Chronic angle-closure glaucoma was diagnosed in 6.6% of the patients. CONCLUSIONS: Primary open-angle glaucoma is the most common form of glaucoma being treated in this outpatient eye clinic in Ghana. Chronic angle-closure glaucoma was the second most common form of glaucoma in this series and was usually undiagnosed due to a lack of gonioscopic evaluation. Gonioscopy is an important diagnostic tool that should be promoted to guide more effective glaucoma treatment in this region. Pseudoexfoliation and pseudoexfoliation-associated glaucoma were not seen in this population.     

Neurofibromatosis and renal artery stenosis: a case of familial incidence

Hypertension as a result of proximal renal artery stenosis has been described in patients with neurofibromatosis, but a review of the English language literature showed no familial incidence of renovascular lesions in association with neurofibromatosis. We report a case of neurofibromatosis in a 24-year-old white woman with renovascular hypertension resulting from a proximal renal artery stenosis and poststenotic aneurysmal degeneration. Her sister, aged 38 years, presented similarly but without clinical evidence of neurofibromatosis. Both sisters had reversed saphenous vein bypass grafting for renal artery stenosis and showed no evidence of pheochromocytoma. Histologic examination of both surgical specimens revealed similar fibrodysplastic changes of the media and adventitia without abnormal neural tissue, findings consistent with those described in patients with neurofibromatosis.     

Health literacy and adherence to glaucoma therapy

PURPOSE: To describe the health literacy of subjects with open angle glaucoma and to investigate the hypothesis that low health literacy is associated with poor glaucoma medication adherence. DESIGN: Cross-sectional patient survey and concomitant chart review. METHODS: One hundred and ninety-seven subjects with open angle glaucoma participated in a survey which included basic demographic information such as age, gender, ethnicity, and level of education completed, and a test of heath literacy, the Rapid Assessment of Adult Literacy in Medicine. Information was collected regarding visual field tests and prescribed medication. The subjects' pharmacies were contacted to ascertain the number of refills requested over the previous six months. RESULTS: Although 146 subjects (74%) reported completing high school, only 94 subjects (48.0%) read at or above a ninth grade level; 23 (11.7%) read at a level of third grade or below. The mean number of refills requested by a subject in the preceding six months was not predicted by race (P = .27,) gender (P = .31), age (P = .92), mean deviation of the visual field (P = .36), or level of education (P = .58). There was a positive relationship between health literacy and the number of refills obtained (P = .003). CONCLUSIONS: Many patients with open angle glaucoma may have poor health literacy. The subjects in our study with low literacy were less adherent with their glaucoma medications than those with a higher level of literacy. Interventions specifically targeting patients with low literacy may improve medication adherence.     

Laparoscopic radiofrequency ablation of the liver in proximity to major vasculature: effect of the Pringle maneuver

BACKGROUND AND OBJECTIVES: The Pringle maneuver has been shown to increase ablation size during radiofrequency ablation (RFA). Efficacy of laparoscopic Pringle in proximity to major vasculature has not been well described. Laparoscopic RFA was performed in proximity to major hepatic vessels to examine effects of the Pringle on ablation size and vascular damage. METHODS: Laparoscopic RFA was performed in 10 pigs. Each underwent ablation of a peripheral site, and sites adjacent to the portal and hepatic veins. Ultrasound was used to position the RFA adjacent to vascular structures. US flow characteristics verified occlusion of blood flow. Five pigs underwent laparoscopic RFA with Pringle and five underwent laparoscopic RFA alone. Animals were then sacrificed for gross and microscopic evaluation. RESULTS: Peripheral, hepatic, and portal vein ablations showed no significant differences in volume between non-Pringle and Pringle lesions, though the median ablation volume for the peripheral site in the Pringle group was approximately twice that of the non-Pringle group. Pringle group overall median time to target temperature was significantly shorter (P = 0.047). Histologic examination revealed no evidence of endothelial damage or thermal-induced intravascular thrombosis of the hepatic or portal veins. CONCLUSIONS: Laparoscopic RFA with Pringle in proximity to major vascular structures does not significantly increase ablation size, or cause acute vascular damage. Further studies are necessary to determine the utility of the Pringle in proximity to major intrahepatic blood vessels.     

Red cell phosphate metabolism in full-term neonates

The effects of hypoxia and feeding on red cell inorganic phosphate (Pi) concentrations were studied in neonates. Although hypoxia caused a rise in extracellular Pi, the intracellular concentration of this ion did not change in comparison to control infants of the same age (first 24 h). As a result of these changes, the distribution of phosphate ions across the erythrocyte membrane was significantly lower in the hypoxic infants than in the controls. In the hypoxic infants, adenosine triphosphate (ATP) levels in the red cells were found significantly lower than in controls, while the 2,3-diphosphoglycerate (2,3-DPG) levels were raised. In breast-fed 2 or 3-day-old neonates, both plasma and red cell Pi were found to be increased but to different degrees, affecting therefore the molar Pi distribution, which was lower than in the controls of the first day. In these infants, ATP was lower and 2,3-DPG higher than in the controls of the first day of life. These findings suggest that intracellular phosphate metabolism in neonates does not follow extracellular phosphate changes. Further investigation is needed to elucidate the controlling factors.     

Decreased production of suppressive-B-cell factor by synovial membrane B-lymphocytes in rheumatoid arthritis

Suppressive-B-cell factor (SBF) is an autoregulatory B-cell lymphokine produced by heat-aggregated-IgG stimulated B-lymphocytes which suppresses polyclonal immunoglobulin production. SBF production by rheumatoid arthritis (RA) patients' peripheral blood B-lymphocytes inversely correlates with disease activity and in vitro rheumatoid factor production. To further define the role of SBF in the pathogenesis of RA, the present study measured SBF production by surgically-obtained synovial membrane mononuclear leukocytes. SBF production by RA synovial leukocytes was similar to the levels previously described for RA peripheral blood leukocytes. Both RA and osteoarthritis (OA) synovial leukocytes produced significantly less SBF than leukocytes obtained from otherwise healthy patients with plica. OA patients produced less SBF than RA patients, but the difference was not statistically significant. SBF values for combined RA patients and controls with OA or plica correlated with the degree of histological plasma cell infiltration providing further evidence for SBF production by cells of the B-lymphocyte lineage. Depletion studies also demonstrated that synovial SBF was produced by B-lymphocytes. The molecular weight (34,000) of synovial SBF was similar to the molecular weight of peripheral blood SBF. Decreased SBF production by RA synovial B-lymphocytes is a functional abnormality in RA which may contribute to the perpetuation of synovial rheumatoid factor production and chronic synovial inflammation.     

Features of the cerebral vascular pattern that predict vulnerability to perfusion or oxygenation deficiency: an anatomic study

In an ongoing study of brain microvasculature in humans at autopsy, we had the opportunity to analyze the overall scheme of this vascular supply. The native endothelial membrane enzyme, alkaline phosphatase, is used to precipitate black lead sulfide salt in the vessel wall, rendering the brain microvasculature visible by both light microscopy and microradiography. There are six distinct patterns of intraparenchymal afferent blood supply to the supratentorial brain: short arterioles from a single source (e.g., those in the cortex); short- to intermediate-length arterioles, single source (anterior two-thirds of the corpus callosum); short- to intermediate length arterioles and arteries, dual source (subcortical U fibers); intermediate-length arterioles and arteries, triple source (extreme/external capsule and claustrum); long arteries and arterioles, single source (centrum semiovale); and large, long muscular arteries, single source (thalamus and basal ganglia). The nature of this arrangement offers some protection to certain regions of the cerebrum from circulatory challenges such as hypotension, while leaving other areas vulnerable. The distal arterioles supplying two of these protected regions, the U-fiber area and the extreme/external capsule and claustrum area, also exhibit the feature of interdigitation, which can offer additional collateral potential from one arteriolar territory to the next. Aging, hypertension, diabetes mellitus, and atherosclerosis can have a significant impact on brain microcirculation. The way in which vascular patterns dictate the distribution of these effects is discussed. The ability to stain the cerebral microvessels and demonstrate the finer points of their patterns in sections and microradiographs has enabled us to resolve some long-standing questions about vascular connections and directions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Bone minerals in β-thalassemia minor

Homozygous β-thalassemia is a severe hereditary disorder associated with osteopenia. Recently it was suggested that thalassemia minor may be a risk factor for osteoporosis. The purpose of the present study was to investigate this suggestion. Bone mineral status was assessed in 22 premenopausal women and 21 men with β-thalassemia minor. In vivo neutron activation analysis was applied to measure hand-bone phosphorus (HBP), single-photon absorptiometry to measure forearm bone mineral content (BMC), and dual-energy X-ray absorptiometry to measure spinal bone mineral density (BMD). Comparison of the HBP, BMC, and BMD values with those of sex- and age-matched healthy subjects without the β-thalassemia trait failed to indicate a statistically significant difference for either sex group. Concerning the biochemical markers of bone metabolism that were studied (serum calcium, phosphate, alkaline phosphatase, osteocalcin, and parathyroid hormone, and 3-h fasting urine calcium-tourine creatinine ratio) no difference was observed between thestudy subjects and matched controls. In conclusion, the present study showed that subjects with β-thalassemia minor are not at risk for osteoporosis.     

Apoptosis in leukoaraiosis

We report a case of leukoaraiosis that was studied for apoptosis. In the neuropil, the number of cells that showed DNA fragmentation was 2.5 times as great in the area of leukoaraiosis as in the adjacent white matter (P = .004) and 25 times as great as in the nearby cortex (P < .001). Our findings suggest that apoptosis, predominantly of oligodendrocytes, is involved in the pathogenesis of leukoaraiosis. Within the area of leukoaraiosis, we also found numerous small veins that were partially occluded by severe collagenous thickening of the vessel walls. This collagenosis may have contributed to or resulted from chronic ischemia in that area.     

Use of phosphorous-31 nuclear magnetic resonance spectroscopy to determine safe timing of chemotherapy after hepatic resection

Liver resection induces accelerated growth of residual hepatic micrometastases. Adjuvant chemotherapy may improve outcome if administered early after resection but may prove lethal if initiated prior to completion of DNA synthesis in regenerating liver. This study investigates phosphorus-31 nuclear magnetic resonance ((31)P-NMR) as a noninvasive tool for measuring energy changes reflective of hepatic DNA synthesis and for predicting safe timing of chemotherapy after 70% hepatectomy. To evaluate metabolic changes in regenerating liver, quantitative three-dimensional (31)P-NMR was performed, using the technique of chemical shift imaging at various time points after 70% hepatectomy in adult male Fischer rats. Animals receiving a course of 2'-deoxy-5-fluorouridine (FUDR; 100 mg/kg, i.p. four times per day x 5), initiated at the time of operation, were also evaluated to observe the effects of chemotherapy on liver regeneration. Forty-eight hours after resection, hepatic nucleoside triphosphate (NTP), which reflects ATP content, fell 37% (P < 0.03) in animals undergoing hepatectomy alone. By contrast, animals receiving FUDR after hepatectomy demonstrated a mitigated NTP response, with a drop of only 17% (P = not significant), suggesting that interruption of DNA synthesis leads to a reduced consumption of ATP. Direct measures of DNA synthesis and nuclear proliferation were correlated with NMR findings. [(3)H]Thymidine incorporation and Ki67 immunohistochemistry were performed on liver samples from rats undergoing 70% hepatectomy with and without FUDR. Both [(3)H]thymidine incorporation and Ki67 expression were inhibited significantly at 48 h in animals receiving hepatectomy and FUDR, compared with those not treated with FUDR. To determine whether NMR changes could be used to identify safe timing of chemotherapy after hepatectomy, rats were treated with a 5-day course of FUDR initiated either prior to or after NMR changes normalized. Animals treated with FUDR at the point of NTP normalization (72 h) showed significantly improved survival over those that began treatment at operation (75 % versus 17 %; P = 0.0005, log rank test). FUDR inhibits hepatic DNA synthesis and influences mortality if administered too early after hepatectomy. Chemical shift imaging is a noninvasive tool that can identify metabolic changes coinciding with DNA synthesis and nuclear proliferation after hepatectomy. (31)P-NMR may be useful for determining safe timing of chemotherapy after liver resection.