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Biomedical subjects

I Pepper

Publications and source records attributed to I Pepper.

8 recordsLinked to original sources
PubMed2002

Quantifying relative afferent pupillary defects using a Sbisa bar.

AIM: To compare the Sbisa bar (Bagolini filter bar) with neutral density filters (NDF) in quantifying relative afferent pupillary defects (RAPD). METHODS: 11 patients with a RAPD were graded and a neutral density filter bar was used to quantify the RAPD. This was repeated using the Sbisa bar. The Sbisa bar (Bagolini filter bar) is used by orthoptists to quantify density of suppression in amblyopia and is of a similar construct to NDFs. Before this clinical part of the study the luminance for each filter was measured, which enabled a direct comparison to be made. RESULTS: In the analysis of patients with RAPD a high correlation was found when comparing the Sbisa and NDF bars r = 0.95. This was statistically significant (p = <0.001). Correlation was also high when the luminance values for the filters were substituted for the clinical readings (r = 0.92; p=<0.001). CONCLUSION: The Sbisa bar is a comparable instrument to the NDF bar in measuring RAPD. Its availability in the clinical situation makes it a practical choice.

Female↗
PubMed2000

Reliability of Snellen charts for testing visual acuity for driving: prospective study and postal questionnaire.

OBJECTIVES: To assess the ability of patients with binocular 6/9 or 6/12 vision on the Snellen chart (Snellen acuity) to read a number plate at 20.5 m (the required standard for driving) and to determine how health professionals advise such patients about driving. DESIGN: Prospective study of patients and postal questionnaire to healthcare professionals. SUBJECTS: 50 patients with 6/9 vision and 50 with 6/12 vision and 100 general practitioners, 100 optometrists or opticians, and 100 ophthalmologists. SETTING: Ophthalmology outpatient clinics in Sheffield. MAIN OUTCOME MEASURES: Ability to read a number plate at 20.5 m and health professionals' advice about driving on the basis of visual acuity. RESULTS: 26% of patients with 6/9 vision failed the number plate test, and 34% with 6/12 vision passed it. Of the general practitioners advising patients with 6/9 vision, 76% said the patients could drive, 13% said they should not drive, and 11% were unsure. Of the general practitioners advising patients with 6/12 vision, 21% said the patients could drive, 54% said they should not drive, and 25% were unsure. The level of acuity at which optometrists, opticians, and ophthalmologists would advise drivers against driving ranged from 6/9(-2) (ability to read all except two letters on the 6/9 line of the Snellen chart) to less than 6/18. CONCLUSIONS: Snellen acuity is a poor predictor of an individual's ability to meet the required visual standard for driving. Patients with 6/9 vision or less should be warned that they may fail to meet this standard, but those with 6/12 vision should not be assumed to be below the standard.

Automobile Driving↗
PubMed1997

Kupffer cell function in thyroid hormone-induced liver oxidative stress in the rat.

The influence of thyroid hormone (L-3, 3', 5-triiodothyronine, T3) on Kupffer cell function was studied in the isolated perfused rat liver by colloidal carbon infusion. Rates of carbon uptake were determined from the influent minus effluent concentration difference and the flow rate, and the respective carbon-induced respiratory activity was calculated by integration of the area under the O2 curves during carbon infusion. In the concentration range of 0.2 to 2.0 mg of carbon/ml, livers from euthyroid rats exhibited a sigmoidal-type kinetics of carbon uptake, with a Vmax of 4.8 mg/g liver/min and a concentration of 0.82 mg/ml for half-maximal rate; carbon-induced O2 uptake presented a hyperbolic-type kinetics, with a Vmax of 4.57 mumol of O2/g liver and a K(m) of 0.74 mg of carbon/ml, which significantly correlates with the carbon uptake rates. Light-microscopy showed that carbon was taken up exclusively by non-parenchymal cells, predominantly by Kupffer cells. Thyroid calorigenesis was found in parallel with increased rates of hepatic O2 consumption and thiobarbituric acid reactive substances (TBARS) formation, glutathione (GSH) depletion, and higher sinusoidal lactate dehydrogenase (LDH) efflux compared to control values. In the concentration range of 0.25 to 0.75 mg/ml, carbon infusion did not modify liver LDH efflux in control rats, while it was significantly enhanced in T3-treated animals. In this latter group, higher carbon concentrations (1 and 1.3 mg/ml) led to loss of viability of the liver. At 0.25 to 0.75 mg of carbon/ml, both the rates of carbon uptake and the associated carbon-induced respiratory activities were significantly increased by T3 treatment, effects that were abolished by pretreatment of the rats with gadolinium chloride (GdCl3). In addition, GdCl3 decreased by 50% the changes induced by T3 in hepatic GSH content and TBARS formation. It is concluded that hyperthyroidism enhances Kupffer cell function, correlated with the increased number of liver macrophages observed histologically, which may represent an alternate source of reactive O2 species to that induced in parenchymal cells, thus contributing to the enhanced oxidative stress status developed.

Animals↗
PubMed1997

[Gastric cancer: a unique etiological entity?].

Based on epidemiological, clinical and pathological data, the existence of two etiologic entities, for what is generically considered as gastric carcinoma, is postulated. Environmental factors would be more important in the etiology of the differentiated type of gastric cancer and genetic factors would have a relevant role in the etiology of the undifferentiated type. Geographic, ethnic, environmental and genetic factors participate in the epidemiology of gastric cancer. This review emphasizes the evidences supporting the role of genetic factors in the etiology of undifferentiated gastric cancer. The importance of looking for a shared phenotype among patients with this type of cancer is underscored.

Carcinoma↗