Multifocal pattern electroretinogram: cellular origins and clinical implications.

PURPOSES: The purposes of this article are to gain insight into the cellular origins of the multifocal pattern electroretinogram (mPERG) and evaluate its potential for clinical use. METHODS: mPERGs were recorded from four anesthetized monkeys before and after pharmacologic blockade of light-driven activity of inner-retinal neurons and from 55 normal human subjects (19-91 years) and six patients with glaucoma (43-77 years of age). Stimuli consisted of counterphase-modulated black and white triangles organized in 61-scaled hexagons with mean luminance 100 cd/m2 and 100% contrast. The stimulus array subtended 31 degrees vertically and 37 degrees horizontally at 48 cm. The amplifier cutoff frequencies were 3 and 100 Hz. Responses were grouped as quadrants and the first slice of the second-order kernel was analyzed. RESULTS: The mPERG responses of monkeys and humans were similar. In the monkey responses, there was an early positive potential (P1) around 25 ms and a later positive potential (P2) found selectively in the nasal field quadrants around 31 ms. These responses were seen around 22 and 36 ms in the human responses. After blockade of inner-retinal activity in monkeys, P1 amplitude was greatly reduced at all retinal locations and P2 was eliminated. P1 and P2 amplitudes were significantly reduced in the glaucomatous eyes relative to amplitudes of age-matched controls. Reductions in the amplitudes of P1 and P2 could easily discriminate between glaucomatous visual field quadrants with and without behavioral sensitivity losses. However, these alterations are likely to reflect diffuse losses. CONCLUSIONS: mPERG responses contain prominent contributions from inner-retinal neurons that can be reduced in glaucomatous eyes. These findings raise the possibility that the mPERG could be potentially useful in the objective estimation of neural damage in glaucoma. However, further refinement of recording techniques will be required if the mPERG is to be used to detect focal damage.     

Biochemical Changes and Pulmonary Response of Guinea Pigs to Asbestos Dust

Abstract The biochemical and histopathological changes in lungs of guinea pigs were studied 120 days after intratracheal injection of three varieties of asbestos dusts, viz. chrysotile, amosite and anthophyllite. The salient histopathological features observed were the development of dust cell lesions in the lungs of animals exposed to the different varieties of asbestos. Maximum fibrosis and minimal asbestos body formation was observed in animals exposed to chrysotile and anthophyllite, respectively. With amosite and anthophyllite the development of diffuse interstitial fibrosis ensued, accompanied by well developed asbestos body formation in the amosite exposed animals. Biochemical studies revealed significant alterations in various phosphorylated compounds, an accumulation of orthophosphate and depletion of esters and nucleotides being very marked. RNA content increased significantly in the amosite treated group while the nucleic acid content remained unaltered in the chrysotile group.     

Influence of Casearia esculenta root extract on glycoprotein components in streptozotocin diabetic rats

The present study was aimed to evaluate the role of the indigenous antidiabetic medicinal plant Casearia esculenta on glycoprotein components in streptozotocin-induced diabetic rats in plasma, liver, kidney and cardiac tissues. Streptozotocin injection (50 mg/kg body weight) caused massive elevation of glycoprotein components such as hexose, hexosamine, sialic acid and fucose in plasma and tissues of diabetic control and experimental animals. Oral administration of C. esculenta root extract (200 and 300 mg/kg body weight) for 45 days significantly reverted the hexose, hexosamine, sialic acid and fucose levels to near normal values. These results suggest a normalizing effect of C. esculenta on glycoprotein components in STZ diabetic rats.     

Unintentional injuries in the home in the United States Part I: mortality

BACKGROUND: Unintentional injuries are a leading cause of death in the United States. It is unclear, however, what proportion of these injuries occur in the home. The purpose of this paper is to quantify and describe fatal unintentional injuries that take place in the home environment. METHODS: Data from the National Vital Statistics System (NVSS) were used to calculate average annual rates for unintentional home injury deaths, with 95% confidence intervals from 1992 to 1999 for the United States overall, and by mechanism of injury, gender, and age group. RESULTS: From 1992 to 1999, an average of 18,048 unintentional home injury deaths occurred annually in the United States (6.83 deaths per 100,000). Home injury deaths varied by age and gender, with males having higher rates of home injury death than females (8.78 vs 4.97 per 100,000), and older adults (>/=70 years) having higher rates than all other age groups. Falls (2.25 per 100,000), poisoning (1.83 per 100,000), and fire/burn injuries (1.29 per 100,000) were the leading causes of home injury death. Rates of fall death were highest for older adults, poisoning deaths were highest among middle-aged adults, and fire/burn death rates were highest among children. Inhalation/suffocation and drowning deaths were important injury issues for young children. CONCLUSIONS: Unintentional injury in the home is a significant problem. Specific home injury issues include falls among older adults, poisonings among middle-aged adults, fire/burn injuries among older adults and children, and inhalation/suffocation and drowning among young children. In addition, recommendations are presented for improvements to the NVSS.     

Nature and correlates of SF-12 physical and mental quality of life components among low-income HIV adults using an HIV service center

Objectives: This study describes health-related quality of life (HRQOL) among low-income HIV adults using an HIV service center, compares participants scores to US published norms for the general population and persons with chronic conditions, and examines relationships between patient characteristics, nonadherence, and HRQOL. Methods: A cross-sectional survey of individuals on antiretroviral therapy was conducted. The Medical Outcomes Study SF-12 was used to assess HRQOL. Medication nonadherence was assessed using the 9-item Morisky Adherence Scale. Data also were collected on social support, CD4 cell count, and time since diagnosis. Results: Approximately 84% of the 86 participants were male, 50% were white, and 39% were black. The ean ± SD Physical component summary (PCS-12) score of 41.0 ± 12.5 and Mental component summary (MCS-12) score of 41.9 ± 11.0 were lower than US general population norms (p < 0.001). PCS-12 scores were similar to those of patients with other chronic conditions. Respondents reported lower MCS-12 scores than patients with hypertension and diabetes (p < 0.006). Employment and higher social support had positive associations with PCS-12 scores and nonadherence had a negative association with MCS-12 scores (p < 0.05). Conclusions: HRQOL in this sample of low-income HIV adults was comparable to other HIV populations. Identifying strategies for increasing social support and medication adherence for economically disadvantaged persons with HIV/AIDS may improve their HRQOL.Rodney Anderson: At the time of the study Dr. Anderson was Director of Health & Education Services The Damien Center 1350 Pennsylvania Indianapolis, IN 46202, USA     

Myocardial infarction in young adults

Although myocardial infarction (MI) mainly occurs in patients older than 45, young men or women can suffer MI. Fortunately, its incidence is not common in patients younger than 45 years. However, the disease carries a significant morbidity, psychological effects, and financial constraints for the person and the family when it occurs at a young age. The causes of MI among patients aged less than 45 can be divided into four groups: (1) atheromatous coronary artery disease; (2) non-atheromatous coronary artery disease; (2) hyper-coagulable states; (4) MI related to substance misuse. There is a considerable overlap between all the groups. This article reviews the literature and highlights the practical issues involved in the management of young adults with MI.     

ENPP1/PC-1 K121Q polymorphism and genetic susceptibility to type 2 diabetes

Genetic susceptibility modulates the impact of obesity on risk for type 2 diabetes. The present study evaluates the role of ENPP1 K121Q polymorphism in prediction of type 2 diabetes in three populations that differ in susceptibility to diabetes and environmental exposure. The three cohorts included 679 nonmigrant South Asians living in Chennai, India (223 with type 2 diabetes); 1,083 migrant South Asians living in Dallas, Texas (121 with type 2 diabetes); and 858 nonmigrant Caucasians living in Dallas, Texas (141 with type 2 diabetes). Patients with type 2 diabetes were included in these cohorts if they had diabetes onset before the age of 60 years. The prevalence of subjects carrying the polymorphic ENPP1 121Q allele was 25% in the nondiabetic group and 34% in the diabetic group of South Asians living in Chennai (P = 0.01). The prevalence in the nondiabetic and diabetic groups were 33 and 45% (P = 0.01) for the South Asians living in Dallas and 26 and 39% (P = 0.003) for the Caucasians. Although further replication studies are necessary to test the validity of the described genotype-phenotype relationship, our study supports the hypothesis that ENPP1 121Q predicts genetic susceptibility to type 2 diabetes in both South Asians and Caucasians.