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Biomedical subjects

A Shapiro

Publications and source records attributed to A Shapiro.

At least 109 records · Page 6Linked to original sources
PubMed1994

Safe food manufacturing.

Food safety is a growing preoccupation of the health authorities and the major food companies in any European country. All the aspects of food manufacturing, from the raw materials until the product is consumed have to insure they are innoxious to human health, eliminate any harmful effects related either to food handling or consumption in domestic or common eating places, as well as protect, as much as possible, our environment. Thus, the food manufacturer has to examine step-by-step the security of the agro-cultures, their composition, but also the possible residues of pollutants and contaminants, or chemicals used to protect them against various pests and determine the possible loss or retention of these substances during technological processes. Animal raw materials should not contain veterinary drug residues or an abnormal amount of some components that result from inadequate feeding. Care should be taken to ensure the security of foods manufactured by biotechnology processes. The organisms and the whole processes used in food biotechnologies should eliminate any impurities. Any minor food ingredients, such as food additives, are under a permanent revision from the point of view of their safety. The industry reacts immediately if any justification requires that a particular food additive should not be used. In other words all the raw materials must conform to their specifications. Technological processes must create a food with an adequate microbiological quality, e.g. free of pathogens and their toxic metabolites. Any danger of microbiological contamination or accidental pollution, such as mechanical particles, chemical substances, etc. should be eliminated. The particular role of food packaging is crucial, since this is a barrier to protect the food against further parasites or microbial contamination and preserve the food from alterations due to enzymatic reactions that require particular oxygen and water activity conditions. The packaging should also protect against possible criminal damage. In addition, the material of packaging should not allow micro-migration to the food. It should be inert against its food content. Another aspect of food packaging that has to be taken into account is its recovery and recyclability. Finally, the food manufacturer has to ensure that the nutritional value of the product does not diminish through its shelf-life. The consumer should be advised about the effects of culinary practices since some of them, such as deep frying or grilling under certain circumstances, may create undesirable substances potentially harmful to human health. The food manufacturing in the context of the environment protection requires a separate issue.(ABSTRACT TRUNCATED AT 400 WORDS)

Consumer Product Safety↗
PubMed1994

Chicken soup revisited: calcium content of soup increases with duration of cooking.

Because low dietary calcium intake may accelerate bone loss, patients often are advised to increase their dietary intake of calcium. However, some patients may be unable to tolerate good calcium sources such as dairy products. We postulated that the calcium content of soups and stews could be increased by prolonged cooking with a beef bone. Three experiments were done to prove this theory: (1) a bone soup made with a beef bone and distilled water, cooked for 24 hours; (2) a bone-vegetable soup cooked the same way; and (3) a vegetable soup made the same way but without the bone. It was concluded that prolonged cooking of a bone in soup increases the calcium content of the soup when cooked at an acidic, but not at a neutral pH.

Animals↗
PubMed1994

Obstruction of urethral stents by mucosal overgrowth.

Urethral strictures are difficult to cure. In 1988, a new treatment was reported, consisting of dilation or incision of the stricture followed by implantation of a specially designed stent meant to allow the urethral epithelium to heal and cover the stent while preventing shrinkage of the scar and reappearance of the stricture. Two cases are reported here in which implantation of the stent resulted in a foreign-body reaction and obstruction of the lumen of the urethra. The area obstructed was reopened by transurethral removal of the reactive tissue. The long-term effect of this reaction on the patency of the urethra is still unknown.

Aged↗
PubMed1994

Toxic effects of systemic retinoids on meibomian glands.

Systemic use of retinoids is common in the treatment of various dermatological disorders. Blepharitis and conjunctivitis have been reported in 20-45% of the patients following systemic treatment with 13-cis-retinoic acid. Our purpose was to study the histopathological changes in the eyelids caused by long-term systemic treatment of female New Zealand rabbits with isotretinoin (2 mg/kg) and etretinate (2 mg/kg). The histopathological evaluation showed degenerative changes in the meibomian gland acini, leading to cell necrosis and a decrease in the basaloid cells lining the acini walls. No evidence of acute or chronic inflammatory reaction was noted.

Administration, Oral↗
PubMed1994

Tuberculous arthritis in children. Diagnosis by needle biopsy of the synovium.

In two children ages 8 months and 4 years, tuberculous synovitis of the knee was suggested by pathologic examination of synovial tissue obtained through needle biopsy. Culture of the biopsy material was positive for Mycobacterium tuberculosis in one case. In this child, the tuberculin test was negative, in the absence of anergy, at the time the child was first evaluated, and the primary lung lesion was not identified by the radiologist. Tuberculous synovitis has not previously been recognized as part of primary tuberculosis during the early weeks when the tuberculin skin test may be negative. Magnetic resonance imaging (MRI) is a sensitive modality for demonstrating joint fluid, synovial hypertrophy, and associated osteomyelitis, if present. With the increasing frequency of cases of tuberculosis in the population, greater awareness of the risk of tuberculous arthritis in childhood is important in order to recognize this unusual presentation. If negative early on, the tuberculin skin test should be repeated after 6 weeks of arthritis. A needle biopsy of the synovium is helpful and appropriate in all children with monoarticular arthritis who have a positive tuberculin skin test.

Biopsy, Needle↗
PubMed1994

The clinical utility of transrectal ultrasound and digital rectal examination in the diagnosis of prostate cancer.

The development of high definition transrectal ultrasound probes has led to an increased interest in the ability of transrectal ultrasound of the prostate (TRUS) to assist in the diagnosis and management of prostate cancer. The present study was designed to examine the correlation of TRUS with digital rectal examination (DRE). The study group comprised 471 patients in whom the results of (a) DRE, (b) TRUS, and (c) histology of tissue obtained by transrectal biopsy of the prostate (TB), were all available. In those patients where both TRUS and DRE were negative, but prostate specific antigen (PSA) was greater than 10 micrograms ml-1, six random biopsies were performed. In all other cases the biopsies were TRUS directed to the suspicious lesion. There were 142 cases in whom both DRE and TRUS were negative or only mildly suspicious of malignancy. TB in these cases was positive for cancer in 17 cases (12%). In a further 126 cases, TRUS was positive for cancer, while DRE demonstrated no suspicious nodule. TB was positive in only 17 of these cases (13.5%). Similarly, in the 31 cases in which DRE was positive but TRUS was negative, TB was positive in only three cases (10%). In the 172 cases in whom both DRE and TRUS were positive, 99 biopsies were positive (57.5%). It was concluded from this study that DRE remains the most valuable single examination in the diagnosis of prostate cancer. TRUS increases the sensitivity of DRE if both are positive. When there is a discrepancy between the two examinations, the biopsy yield is low. When both are positive, a high cancer yield is obtained, TRUS having added value in directing the biopsy needle to the suspicious site. TRUS is thus a valuable adjunct to DRE in the diagnosis of prostate cancer.

Diagnosis, Computer-Assisted↗
PubMed1993

[Monocular blindness following blunt head trauma].

An uncommon, devastating complication of blunt head trauma is monocular blindness. We present a 40-year-old man who complained of visual loss in the right eye a few days after minor closed head trauma. Electrophysiologic study (VEP) proved severe damage to the right optic nerve, most probably due to transection of the nerve. Based on the assumption that optic nerve injury might be analogous to spinal cord injury, we used methylprednisolone: a loading dose of 30 mg/kg was followed 2 hours later by 15 mg/kg, which was then given every 6 hours for 48 hours. Surgical decompression of the bony optic canal was not performed. There are no good data to guide our decision-making. A prospective randomized trial is required to provide definitive management guidelines in this severe and dramatic injury.

Adult↗
PubMed1993

The pattern of spontaneous germ-line mutation: relative rates of mutation at or near CpG dinucleotides in the factor IX gene.

Mutations at CpG dinucleotides were delineated in the factor IX gene of 38 hemophilia B patients. When transitions at CpG were considered with those previously reported by us and those compiled in the factor IX mutation database, the following patterns emerged. Many CpG sites were mutated with high frequency, while two CpG sites were infrequently mutated (R29-->Q and R116-->TGA). Of the 6 possible nonsense mutations and the 14 missense mutations that would produce a nonconservative change at conserved amino acids, all have been observed to cause hemophilia B except A-10-->T and R338-->Q. By contrast, none of the 6 missense changes at nonconserved amino acids have been observed to cause hemophilia B. At those CpG sites that are frequently mutated, the rate of transitions is estimated to be 20-fold higher than transitions at non-CpG sites. Point mutations in close proximity to CpG dinucleotides did not seem elevated.

DNA Mutational Analysis↗
PubMed1993

Endoscopic sinus surgery: 4-year follow-up on the first 100 patients.

Endoscopic sinus surgery has been reported to be successful, but lack of a standardized classification system hampers comparison of results between studies, and long-term results of surgery have not been reported in a series of consecutive patients. The results of our first 100 endoscopic sinus surgery procedures, reported previously after an average 9-month follow-up, were reviewed with the application of a new classification scheme and in light of a longer (4-year) follow-up. Surgery was successful in all patients whose sinus symptoms resulted from anatomical variations or suppurative infection, but failed in some patients with hyperplastic disease or polyps. In addition, the presence of reactive airway disease or the acetylsalicylic acid (ASA) triad was a bad prognostic sign. The overall success of the procedure in relieving sinus symptoms decreased from 98% at early follow-up to 91% at 4-year follow-up. Sixty-six percent were successful after one procedure and 25% required more than one procedure to achieve success. The decline in success since our first report in 1990 was mostly attributable to late failure in patients with recurrent symptomatic polyposis. Because symptoms may not recur in these patients for up to 3 years, long-term results of surgery for this disorder are necessary. Symptoms of recurrent polyposis can be controlled medically or by revision surgery.

Endoscopy↗
PubMed1993

Chromatic and luminance sensitivity in diabetes and glaucoma.

The effects of glaucoma and diabetes on the sensitivities of the opponent and achromatic systems were investigated by measuring thresholds along theoretically defined axes in a three-dimensional color space. Thresholds were measured along two equiluminant chromatic axes and one achromatic axis in patients with diabetes or glaucoma and in glaucoma suspects. The results were compared with measures of sensitivities of short- and middle-wavelength-sensitive-cone pathways [S (Stiles pi 1) and M (Stiles pi 4), respectively] and with measures of hue discrimination by use of the Farnsworth-Munsell 100-hue test. The glaucoma suspects and diabetic patients showed preferential S-cone-pathway sensitivity losses. For glaucoma patients, however, these losses were associated with significant decreases in the sensitivity of the L-M opponent system and with decreased sensitivity to achromatic contrast.

Adolescent↗
PubMed1993

Handling punctate keratitis resulting from systemic cytarabine.

A young patient with acute myelogenous leukemia was treated with high-dose cytarabine (3.0 g/m2 every 12 hours). After five days of treatment, he developed severe photophobia and decreased visual acuity. On examination, progressive punctate keratitis was found. We discuss the mechanism of the cytarabine-induced corneal toxicity and the prophylactic use of topical corticosteroids.

Adult↗
PubMed1992

A method for multiple superposition of structures.

The study of families of protein structures is important in analysing the results of NMR structure determinations and in investigating mechanisms of molecular evolution at the level of conformation. A method is discussed for finding the transformations that mutually superpose an arbitrary number of structures in the least-squares sense given specified atom-to-atom correspondence.

Least-Squares Analysis↗
PubMed1992

The effect of adaptation on the differential sensitivity of the S-cone color system.

This paper presents a psychophysical dissection of the S-cone color system. Experiments were guided by a skeletal model that assumed a first stage consisting of S-, M- and L-cones, and a second stage of the opponent combination of the S and L+M signals. The response of the S-cone system was isolated by measuring difference thresholds between lights that were equiluminant tritanopic confusion pairs and thus differed only in S-cone excitation. Two types of mechanisms that control sensitivity in the S-cone system were identified: (i) static mechanisms that have a restricted range and thus limit discrimination to a small range of inputs; and (ii) adaptive mechanisms that change the state of the system in response to changes in steady illumination, so that the system is sensitive to small changes from the adapting light. These mechanisms were localized by lights that stimulated the S-cone system while keeping the signal constant at either the S, the L+M, or the post-opponent stage. The response function of the static mechanism was estimated by measuring difference thresholds at judgment points other than the steady adapting light. This procedure was repeated at a number of adaptation lights to examine the properties of adaptive mechanisms. The data were consistent with an elaborated model that included identical multiplicative gain control mechanisms in the S and L+M pre-opponent branches, and a post-opponent static sigmoidal nonlinearity with different amounts of compression for positive and negative opponent inputs.

Adaptation, Ocular↗
PubMed1992

Extracorporeal shock-wave lithotripsy (ESWL) monotherapy for stones in lower ureter.

Extracorporeal shock-wave lithotripsy (ESWL) has been accepted as the method of choice for most upper urinary tract calculi. However, in cases of stones in the lower ureter, ureteroscopic procedures have generally been preferred. Using the Dornier HM3 lithotriptor with modifications in the patient's position, we were able to successfully treat 155 unselected cases of lower ureteral calculi. The average stone size was 9.6 mm (range 5-23 mm). One hundred forty-three patients had stones located below the lower margin of the sacroiliac joint. These patients were placed in a supine position. The stones were visualized radiologically without use of a ureteral catheter in 78 percent of the patients; in 22 percent a ureteral catheter was inserted prior to ESWL to aid in stone localization. In 145 patients (94%) treatment was completed in one session; 10 patients (6%) required two sessions. Of the patients, 38 percent were free of stones one day after ESWL; 97 percent became stone free within three months, and only 3 patients required endoscopic manipulation, after ESWL. Twelve patients had stones in the midureter overlying the sacroileum. They were placed in the prone position, and the calculi were visualized with the aid of a ureteral catheter. All these patients became free of stones one month after treatment. There were no significant treatment-related complications except for bacteremia in 1 case. In view of the remarkable efficacy, negligible complication rate, and shorter hospital stay as compared to ureteroscopic stone manipulations, we recommend high energy ESWL as the primary monotherapy of mid and lower ureteral stones.

Adolescent↗
PubMed1992

Intravesical lidocaine: topical anesthesia for bladder mucosal biopsies.

The intravesical instillation of lidocaine solution has been used as a topical form of anesthesia for bladder biopsies. We performed 63 ambulatory procedures in which multiple cold-cup biopsies were obtained during cystoscopy. There was no need for electrocautery. All patients tolerated the procedure well and were discharged from the office immediately thereafter. There were no changes in heart rate or blood pressure during the procedures. Serum concentrations of lidocaine were measured in 10 patients at 5, 10 and 30 minutes, and they were clinically insignificant. This simple office procedure can be used for the diagnosis and followup of patients with carcinoma in situ of the bladder.

Administration, Intravesical↗