Anterior keratoconus associated with unilateral cornea guttata.

PURPOSE: To describe a 30-year-old man with bilateral but asymmetric anterior keratoconus and unilateral cornea guttata in the eye with more advanced keratoconus. METHOD: Case report. RESULTS: The patient's keratoconus was diagnosed three or four years earlier. The keratoconus was confirmed by slit-lamp examination, keratometry, and computer-assisted topographic analysis. Cornea guttata were confirmed by clinical examination and specular microscopy. CONCLUSION: This is a rare case of unilateral cornea guttata associated with asymmetric keratoconus, showing severe guttate change only in the eye with more advanced keratoconus.

Making sense of refractive surgery in 2001: why, when, for whom, and by whom?

Surgical alteration of the focusing or refractive properties of the eye has been performed on millions of patients. An array of procedures to correct myopia, hyperopia, astigmatism, and presbyopia have been introduced over the past 25 years with varying degrees of success. Improved technology has increased patient and physician satisfaction and enthusiasm. Currently available surgical procedures can be categorized as incisional, surface-altering, lamellar, and intraocular. The choice of procedure depends on individual patient indications and contraindications based on results of ocular examinations, eg, corneal pachymetry to measure corneal thickness, keratometry to measure the corneal curvature, basal tear secretory rate, and dark-adapted pupil size. The postoperative uncorrected visual acuity depends, in large part, on the quality of the preoperative evaluation and refraction. Before scheduling a patient for surgery, the ophthalmologist must ensure that the patient understands the potential risks of the procedure and has realistic expectations for the postoperative level and quality of uncorrected visual acuity. Postoperative complications include corneal flap displacement, undercorrection and overcorrection, and epithelial ingrowth under the corneal flap and inflammatory keratitis. Postoperative dry eye, infection, and inflammation are usually treated medically. Ongoing technological innovations to customize the surgical approach to an individual patient's eye continue to improve outcomes.

Peripheral nonulcerative keratitis as a presenting sign of microscopic polyangiitis.

PURPOSE: To report a 16-year-old woman who had peripheral keratitis as a presenting sign of microscopic polyangiitis (MPA), which rapidly progressed to acute renal failure. METHOD: Case report. RESULTS: The patient's vasculitis was diagnosed by renal biopsy, which was evaluated with histologic, immunofluorescence, and electron microscopy. The diagnosis was confirmed by laboratory study, which showed a positive antimyeloperoxidase antibody. CONCLUSION: MPA may rarely present with ocular findings and should be considered in the differential diagnosis when a patient has peripheral keratitis.

Disinfection of Goldmann tonometers after contamination with hepatitis C virus.

PURPOSE: To compare methods of disinfecting Goldmann tonometer tips inoculated with hepatitis C virus. METHODS: Hepatitis C virus was placed on Goldmann tonometer tips, air dried, and then disinfected by dry gauze wipes, isopropyl alcohol wipes, cold water washes, povidone iodine 10% wipes, and hydrogen peroxide or isopropyl alcohol soaks followed by a cold water wash and dry. Hydrogen peroxide and isopropyl alcohol disinfection techniques followed the Centers for Disease Control and Prevention guidelines for prevention of possible transmission of human immunodeficiency virus (HIV). After disinfection, samples from tonometer tips were amplified by polymerase chain reaction to quantitate the amount of hepatitis C virus RNA remaining. RESULTS: Percentage of hepatitis C virus RNA remaining after disinfection: dry gauze wipes 95.65%, isopropyl alcohol 5-second wipes 88.91%, cold water wash 4.78%, povidone iodine 10% 5-second wipes 0.72%, hydrogen peroxide soak with cold water wash 0.07%, and isopropyl alcohol soak and cold water wash 0.02%. CONCLUSIONS: After inoculation of Goldmann tonometer tips with hepatitis C virus, a 5-minute soak in 3% hydrogen peroxide or 70% isopropyl alcohol followed by washing in cold water resulted in the greatest reduction in hepatitis C virus RNA.

The Black-Scholes pricing formula in the quantum context.

A natural explanation for extreme irregularities in the evolution of prices in financial markets is provided by quantum effects. The lack of simultaneous observability of relevant variables and the interference of attempted observation with the values of these variables represent such effects. These characteristics have been noted by traders and economists and appear intrinsic to market dynamics. This explanation is explored here in terms of a corresponding generalization of the Wiener process and its role in the Black-Scholes-Merton theory. The differentiability of the Wiener process as a sesquilinear form on a dense domain in the Hilbert space of square-integrable functions over Wiener space is shown and is extended to the quantum context. This provides a basis for a corresponding generalization of the Ito theory of stochastic integration. An extension of the Black-Scholes option pricing formula to the quantum context is deduced.

The outpatient evaluation of hematochezia.

OBJECTIVE: The objective of this study was to determine whether specific clinical symptoms associated with hematochezia are predictive of important GI pathology and whether full colonoscopic examination is necessary. METHODS: A total of 103 outpatients (> or = 45 yr) with hematochezia, defined as the passage of bright red blood per rectum, underwent anoscopy and colonoscopy. Before endoscopy, patients completed a detailed interview, quantitating the amount and frequency of bleeding, weight loss, use of aspirin/NSAIDs, change in bowel habits, family history, and prior GI illnesses. Based on this information, physicians were asked to predict whether the bleeding was from a perianal or more proximal site. At colonoscopy, pathology was stratified as either proximal or distal to the sigmoid/descending junction. Substantial pathology was defined as one or more adenomas > 8 mm, carcinoma, or colitis. RESULTS: Anoscopy demonstrated internal and external hemorrhoids in 78 and 29 patients, respectively. On colonoscopy, 36 patients had 43 substantial lesions. Thirty-seven of these lesions were distal to the junction of the descending and sigmoid colons and six were proximal lesions. Four patients had cancer; all were distal lesions. Patients with substantial lesions were more likely to give a history of blood mixed within their stool (p = 0.03), to have more episodes of hematochezia per month (p = 0.008), and to have a significantly shorter duration of bleeding before medical evaluation (p = 0.02) than did patients without such lesions. However, the physician's clinical assessment did not predict reliably which patients were likely to have substantial pathology. CONCLUSIONS: In patients with hematochezia, clinicians were unable to distinguish between those patients with and those without significant colonic lesions by history alone. Flexible sigmoidoscopy would have demonstrated most (95%) substantial lesions. The lesions that flexible sigmoidoscopy missed were an unlikely cause of bleeding in this small group of patients.

Hemorrhage in the upper gastrointestinal tract in the older patient.

OBJECTIVE: To characterize the natural history of bleeding in the upper GI tract in the older age patient. METHODS: We retrospectively reviewed data on 200 patients admitted with the diagnosis of upper GI bleeding (100 consecutive patients less than 60 yr of age and 100 consecutive patients more than 60 yr of age). Information collected included historical features of presentation, physical examination findings, laboratory data, endoscopic findings, and length of hospital stay. Results were analyzed using X2 and Student's tests. RESULTS: Upon presentation, fewer patients over 60 had a history of alcohol consumption (29 vs 65 patients, p < 0.05). They also had significantly less dyspepsia (49 vs 64 patients, p < 0.05). Findings at endoscopy included more ulcer disease in the older patients (duodenal or gastric ulcer in 73 vs 48 patients, p < 0.05) and more acid peptic disease as well (duodenal ulcer, gastric ulcer, duodenitis, gastritis, or esophagitis in 91 vs 70 patients, p < 0.05). Younger patients had more Mallory-Weiss tears (14 vs three patients, p < 0.05) and a trend toward more variceal bleeds (19 vs 11 patients; p = 0.39). The hospital course in the two groups was not different with regard to the need for intensive care (61 patients under 60 vs 54 patients over 60), number of patients rebleeding (13 patients under 60 vs 15 patients over 60), mean number of blood units transfused (4 units in each group), mean duration of hospital stay (5.6 days in patients under 60 vs 6.0 days in patients over 60), or mortality (six patients in each group). CONCLUSIONS: Compared with younger patients, patients 60 yr of age and older admitted to the hospital for upper GI bleeding are less likely to have a history of alcohol consumption or dyspepsia. They do have a greater likelihood of peptic disease, which accounts for their bleeding. Patients aged 60 yr and older do not have a significantly different hospital course from that of patients less than 60 yr old with regard to need for intensive care, transfusion requirements, duration of hospital stay, or mortality.

Microbial metabolism of tholin.

In this paper, we show that a wide variety of common soil bacteria are able to obtain their carbon and energy needs from tholin (a class of complex organic heteropolymers thought to be widely distributed through the solar system; in this case tholin was produced by passage of electrical discharge through a mixture of methane, ammonia, and water vapor). We have isolated aerobic, anaerobic, and facultatively anaerobic bacteria which are able to use tholin as a sole carbon source. Organisms which metabolize tholin represent a variety of bacterial genera including Clostridium, Pseudomonas, Bacillus, Acinetobacter, Paracoccus, Alcaligenes, Micrococcus, Corynebacterium, Aerobacter, Arthrobacter, Flavobacterium, and Actinomyces. Aerobic tholin-using bacteria were first isolated from soils containing unusual or sparse carbon sources. Some of these organisms were found to be facultatively anaerobic. Strictly anaerobic tholin-using bacteria were isolated from both carbon-rich and carbon-poor anaerobic lake muds. In addition, both aerobic and anaerobic tholin-using bacteria were isolated from common soil collected outside the laboratory building. Some, but not all, of the strains that were able to obtain carbon from tholin were also able to obtain their nitrogen requirements from tholin. Bacteria isolated from common soils were tested for their ability to obtain carbon from the water-soluble fraction, the ethanol-soluble fraction, and the water/ethanol-insoluble fraction of the tholin. Of the 3.5 x 10(7) bacteria isolated per gram of common soils, 1.7, 0.5, and 0.2%, respectively, were able to obtain their carbon requirements from the water-soluble fraction, the ethanol-soluble fraction and the water/ethanol-insoluble fraction of the tholin. The palatability of tholins to modern microbes may have implications for the early evolution of microbial life on Earth. Tholins may have formed the base of the food chain for an early heterotrophic biosphere before the evolution of autotrophy on the early Earth. Where tholins are present on other planets, they could possibly be metabolized by contaminant microorganisms transported to these bodies via spacecraft. Thus, the presence of tholins should be taken into account when evaluating the planetary quarantine requirements for probes to other planets.

Statistical invalidation of the Hubble law.

An optimal nonparametric technique for elimination of the observation cutoff bias, on the assumption of a given theoretical cosmology, is applied to the redshift-magnitude and redshift-angular diameter relationships in objectively specified large galaxy samples. The estimates obtained on the assumptions of linear and square redshift-distance laws are uniformly and strongly favorable to the square law. The question of whether the relative inferiority of the linear law can scientifically be ascribed to ancillary extragalactic phenomena is addressed by nonparametric crosstesting of the alternative hypotheses. Each law is used to predict the results of a statistical analysis based on the alternative law by using the given data and computer simulations. The result is that the square law predicts with statistical exactitude the results of the analyses of the linear law; but the linear law predicts with near certainty that the fit of the square law will be much worse than is observed. In the absence of independent validation of a variety of ancillary hypotheses that have been adduced in connection with the linear law, it seems necessary to conclude that the Hubble law lacks an objective statistical foundation.

The x-ray luminosity-redshift relationship of quasars.

Chronometric cosmology provides an excellent fit for the phenomenological x-ray luminosity-redshift relationship for 49 quasars observed by the Einstein satellite. Analysis of the data on the basis of the Friedmann cosmology leads to a correlation of absolute x-ray luminosity with redshift of >0.8, which is increased to approximately 1 in the bright envelope. Although the trend might be ascribed a priori to an observational magnitude bias, it persists after nonparametric, maximum-likelihood removal of this bias.

Tumor-immunotherapeutic efficacy of Serratia marcescens polyribosomes.

The ability of polyribosomes, obtained from several bacterial species, to suppress the development of cutaneous SaD2 fibrosarcomas in DBA/2 mice were evaluated. Suppression of tumor appearance depended upon the tumor load at the time of treatment, dose of polyribosomes, and species source of polyribosomes, with Serratia marcescens being superior to Escherichia coli, Streptococcus pneumoniae, Mycobacterium bovis (Pasteur), Mycobacterium smegmatis, and Propionibacterium acnes (formerly Corynebacterium parvum). A single injection of 5 or 50 microgram of Serratia polyribosomes at the tumor site 72 hr after the intradermal administration of 1.5 X 10(3) SaD2 cells resulted in 66 to 95% survival. All untreated animals expired within 50 days. Tumor suppression occurred at both flank and footpad sites. Presensitization with polyribosomes and incorporation of polyribosomes into adjuvant were not required for the tumor-suppressive effect. Treatment of Serratia polyribosomes with RNase or pronase reduced the number of survivors. Endotoxin was not detectable with the Limulus amebocyte lysate assay.

Nutrition and family practice.

Where necessary, women should be counselled so as to understand that a slim, elegant figure is not the prerogative of all. An inherited large frame requires a corresponding body contour, and dieting to change this situation will be in vain. All weight reducing diets must provide an adequate amount of vitamins and minerals. Women on the contraceptive pill often have diminished serum levels of folic acid and vitamin B6, and there have been suggestions that vitamin supplementation may help overcome depression and diminished libido in some women. This has been partially successful. A well-balanced diet should be recommended prior to trial of supplements. During pregnancy and lactation there is an increased need for protein, calcium, iron, iodide and fluoride. Vitamin and iron supplementation may be required where deficiencies exist due to dietary neglect. Excessive alcohol and smoking should be discouraged--especially during pregnancy. The elderly are particularly vulnerable to diseases of nutritional deficiency for various reasons. The importance of foods providing protein, calcium and vitamins should be stressed, as these are the main nutrients lacking. The consumption of meat, milk, cheese, eggs, fish, fresh fruit and vegetables should be encouraged.