Search PubMed⌕ Search

Biomedical subjects

J Katz

Publications and source records attributed to J Katz.

At least 145 records · Page 8Linked to original sources
PubMed1999

Host responses to recombinant hemagglutinin B of Porphyromonas gingivalis in an experimental rat model.

Porphyromonas gingivalis, a gram-negative, black-pigmented anaerobe, is among the microorganisms implicated in the etiology of adult periodontal disease. This bacterium possesses a number of factors, including hemagglutinins, of potential importance in virulence. Several hemagglutinin genes have been identified, cloned, and expressed in Escherichia coli. The purpose of this study was to characterize host responses to purified recombinant hemagglutinin B (rHag B), using the conventional Fischer rat as the experimental animal model. The effectiveness of immunization with rHag B on protection against experimental periodontal bone loss following infection with P. gingivalis was also evaluated. Groups of rats were immunized by the subcutaneous route with rHag B in complete Freund's adjuvant, immunized with rHag B and orally infected with P. gingivalis, nonimmunized and noninfected, or orally infected with P. gingivalis only. Serum and saliva samples were collected throughout the experiment and evaluated for serum immunoglobulin G (IgG) and IgM and salivary IgA antibody activity by enzyme-linked immunosorbent assay. No salivary IgA anti-Hag B activity was detected in the various groups of rats. A slight serum IgM response similar to that seen in preimmune samples was observed. Serum IgG antibody activity to Hag B was detected only in samples from rats immunized with rHag B. This response was primarily of the IgG1 and IgG2a subclasses, followed by IgG2b and low levels of IgG2c. Supernatants from rHag B-stimulated splenic lymphoid cell cultures from immunized rats contained high levels of gamma interferon, followed by interleukin-2 (IL-2), IL-10, and then IL-4. These results are consistent with the induction of T helper type 1 (Th1)- and Th2-like responses. Western blot analysis of sera derived from rHag B-immunized rats reacted with trichloroacetic acid (TCA) precipitates of P. gingivalis 33277, 381, A7A1-28, and W50, revealing a 50-kDa band reflective of Hag B. However, sera derived from rats immunized with P. gingivalis whole cells or from rats infected with P. gingivalis only did not react with rHag B but did react with TCA precipitates of P. gingivalis strains. Finally, radiographic measurements of periodontal bone loss indicated that rats immunized with rHag B had less bone loss than those infected with P. gingivalis only. These results demonstrate the effectiveness of purified rHag B in inducing a protective immune response and support the potential usefulness of this component of P. gingivalis in the development of a vaccine against adult periodontitis.

Adhesins, Bacterial↗
PubMed1999

Recycling of glucose and determination of the Cori Cycle and gluconeogenesis.

We have derived equations, by employing [U-(13)C]glucose and mass isotopomer analysis, to determine the pathways of glycogen synthesis (J. Katz, W. P. Lee, P. A. Wals, and E. A. Bergner. J. Biol. Chem. 264: 12994-13004, 1989). More recently, by use of these methods we have derived equations to determine the rate of glucose recycling and of gluconeogenesis [Tayek and Katz. Am. J. Physiol. 270 (Endocrinol. Metab. 33): E709-E717, 1996 and 272 (Endocrinol. Metab. 35): E476-E484, 1997, and Katz and Tayek. Am. J. Physiol. 275 (Endocrinol. Metab. 38): E537-E542, 1988]. The former equations have been criticized and challenged by C. Des Rosiers, B. R. Landau, and H. Brunengraber [Am. J. Physiol. 259 (Endocrinol. Metab. 22): E757-E762, 1990], and the latter recently by B. R. Landau, J. Wahren, S. F. Previs, G. K. Ekberg, D. Yang, and H. Brunengraber [Am. J. Physiol. 274 (Endocrinol. Metab. 37): E954-E961, 1998]. Landau et al. claimed that our equations were in error and "corrected" them. Their analysis, and their values for recycling and gluconeogenesis (GNG) differ markedly from ours. We show here our equations and estimates of recycling and GNG to be correct. We present here a theoretical analysis of recycling and discuss the determination of the Cori Cycle and GNG. We illustrate by numerical examples the difference in parameters of glucose metabolism calculated by the methods of Katz and Landau. J. Radziuk and W. N. P. Lee [Am. J. Physiol. 277 (Endocrinol Metab. 40): E199-E207, 1999] and J. K. Kelleher [Am. J. Physiol. 277 (Endocrinol. Metab. 40): E395-E400, 1999] present a mathematical analysis that, although differing in some respects from Landau's, supports his equation for GNG. We show in the APPENDIX that their derivation of the equation for GNG is incorrect.

Animals↗
PubMed1999

Physical and psychological morbidity after axillary lymph node dissection for breast cancer.

PURPOSE: Alternatives to axillary lymph node dissection (ALND) are being developed amid controversy surrounding the therapeutic benefit and overall utility of this routine surgical procedure. Although potential negative side effects associated with ALND are known, we set out to examine whether these side effects contribute significantly to patient reports of quality of life and mental health. PATIENTS AND METHODS: We surveyed 222 women who had received an ALND as part of breast cancer surgery. All women underwent a physical therapy assessment of range of arm/shoulder motion and completed the Modified Post-operative Pain Questionnaire, the Pain Disability Index, the McGill Pain Questionnaire (short form), the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire, and the Mental Health Inventory. RESULTS: Seventy-two percent of the women experienced arm/shoulder pain, weakness, or numbness in the week before the interview, and range of motion of the affected arm/shoulder was impaired in 73% of the women. Severity of pain was reported to be low to moderate, and younger patients experienced greater pain than older patients. Pain severity correlated positively with the number of lymph nodes removed and receipt of chemotherapy and was not significantly related to length of time since surgery or receipt of radiation therapy. Generally high levels of cancer-specific quality of life and mental health were reported. Quality of life was significantly predicted by the McGill Pain Questionnaire, and mental health was significantly predicted by the Pain Disability Index and the physical therapy assessment. CONCLUSION: Surgery-related symptoms after ALND persist for a majority of women with breast cancer and are not significantly related to time since surgery or receipt of radiation therapy. These symptoms and associated disability are significantly predictive of cancer-specific quality of life and mental health.

Axilla↗
PubMed1999

Neural networks for visual field analysis: how do they compare with other algorithms?

PURPOSE: To compare the performance of a neural network in identifying visual field defects with the performance of other available algorithms. METHODS: A feed-forward neural network with a single hidden layer was trained to recognize visual field defects previously collected in a longitudinal follow-up glaucoma study, and then tested on fields taken from the same study but not used in the training. The receiver operating characteristics of the network then were compared with the previously determined performance of other algorithms on the same data set. RESULTS: At a specificity greater than 90%, the neural network was more sensitive than any of the available algorithms (although only the global indices were available for comparison, as the cluster and cross-meridional algorithms did not achieve such high specificity at their current settings). At a lower specificity (80-85%), the neural network was unable to attain the high sensitivity of the cluster or cross-meridional algorithms; in fact, the cluster algorithm from the Low-Tension Glaucoma study was significantly more sensitive. CONCLUSION: The receiver operating characteristics of a feed-forward neural network designed to detect visual field defects were explored. At a very high specificity (90-95%) a neural network performed better than the global indices. However, at a lower specificity (78%-88%), the neural network performed worse than cluster and cross-meridional algorithms.

Algorithms↗
PubMed1999

The prevalence and treatment of dental caries among Israeli permanent force military personnel.

A survey was conducted to determine dental caries prevalence and treatment among 1,095 25- to 44-year-old permanent force Israeli military personnel. Caries experience, by decayed, missing, and filled permanent teeth (DMFT), was 11.66, with an average of 1.37 untreated caries, 2.40 extracted teeth, and 7.90 treated teeth. Caries was positively associated with age (p < 0.001). Females demonstrated statistically higher DMFT levels than males (p = 0.009). Negative associations were detected for education levels and untreated and extracted components (p < 0.001), and a positive association was detected for the treated caries component (p < 0.001). Permanent military personnel treated by private dentists exhibited 17.6% untreated caries, compared with 9.4% among personnel treated in the army. Officers had lower levels of untreated caries (8.6%) than others (13.3%). Among the present population, 77% had attended a dental clinic in the preceding 2 years. Permanent force personnel are offered free, comprehensive, and accessible dental treatment. The data emphasize a need for further dental health education.

Adult↗
PubMed1999

[Absence of bleeding recurrence of peptic ulcer after long term follow-up of successful eradication of Helicobacter pylori].

Helicobacter pylori (HP) eradication reduces dramatically the peptic ulcer relapse rate, but information regarding recurrence of peptic ulcer bleeding after eradication is still scanty. Available data show rebleeding rates of 0-3% per year in successfully eradication patients, compared with figures between 12 and 33% among the non eradicated ones. The aim of this study was to determine the rebleeding rate among successfully eradicated patients with a prior history of rebleeding peptic ulcer. 42 patients (34 male, mean age 49, range 18-74) hospitalised for Hp positive bleeding peptic ulcer undergoing conservative treatment, were given as soon as oral route was re-established, a one-week eradication treatment, followed by the same proton pump inhibitor for three or five weeks for duodenal and gastric ulcer healing respectively. No maintenance antiulcer therapy was indicated. Patients were advised not to take nonsteroideal anti-inflammatory drug. Ulcer healing and Hp eradication was confirmed in all 42 patients by means of endoscopy and biopsies for urease rapid test and histology four weeks after completion of the treatment. After this patients were invited to enter a long-term follow-up program with periodical visits. End point of the study was occurrence of rebleeding. Further endoscopies were planned when rebleeding or symptomatic relapse. Median follow-up time was 24.02 months, ranging from 3 up to 27 months. All patients were compliant with the follow-up visits. None of the patients presented with symptoms suggestive of ulcer relapse or upper gastrointestinal bleeding. Our data suggest, that Hp eradication can prevent bleeding relapses in patients with Hp positive bleeding peptic ulcers.

Adolescent↗
PubMed1999

[Detection of Helicobacter pylori by polymerase reaction in bile samples from gallbladder and bile stones].

Some papers report helicobacter pylori existence in bile from surgical specimens obtained during gallbladder or bile ducts surgery. The aim of this work was search by PCR, H. Pylori presence in bile specimens from patients suffering of gallbladder stones or by bile ducts stones. Bile samples were obtained by gallbladder punction during cholecystectomy in 26 patients, 19 of them with gallbladder stones and 7 also with gallbladder stones and bile duct stones. Age ranged from 22-69 years old, median 49.6 years old. Samples were sent to specialized biomolecular laboratory to perform PCR techniques. Two of 26 patients (7.6%) had positive reaction for the presence of DNA of H. Pylori in bile samples. Our research suggest that DNA of H. Pylori can be founded in bile samples patients with gallbladders and duct stones in Argentina.

Adult↗
PubMed1999

The relationship between optic disc area and open-angle glaucoma: the Baltimore Eye Survey.

PURPOSE: To determine if eyes with larger optic disc area are more likely to have open-angle glaucoma or to have glaucoma at lower intraocular pressure (IOP). METHODS: Data were collected from a population-based sample of adults residing in East Baltimore, consisting of demographic information, ocular examinations, automated and static/kinetic visual field tests, IOP as measured by applanation tonometry, and image analysis of the optic disc. Optic disc area was calculated using refractive error to correct magnification. Open-angle glaucoma was defined by visual field and optic disc criteria. One eye from each of 75 patients with glaucoma was compared to those of 3,518 subjects without glaucoma. RESULTS: Although optic disc area was somewhat larger among patients with glaucoma than control subjects, in a regression model adjusting for age, gender, and race, the significance of this difference had a probability of 0.06. Among patients with glaucoma, disc area was not related to IOP level measured at study examination. CONCLUSION: Disc area is a weak risk factor for open-angle glaucoma. Disc area did not differ between patients with glaucoma who had lower IOP and those who had higher IOP among a group with glaucoma that were identified in a population survey.

Adult↗
PubMed1999

Behavior of dental phobic residents of large and small communities.

The purpose of the present study was to characterize differences among dental phobic patients in past dental experience between residents of standard metropolitan areas (SMSA), and non-SMSA. Over a period of 1 year, the records of 41 dental phobic patients were evaluated. These patients were attending a special Israeli Defense Force clinic designed to treat dental phobics. The mean time since the last routine visit in both groups was 12.42 +/- 6.54 years and the mean age at which the patients had had their last routine dental treatment was 14.56 +/- 4.62 years. Over a two-year period prior to the present visit, the main reason for SMSA patients to seek any dental care was dental pain (P = 0.015). All other variables that compared the dental behavior of SMSA patients with non-SMSA patients showed no difference. The findings suggest that the availability of dentists in the SMSA did not increase the seeking of dental care. The fact that SMSA residents were more likely to seek care because of pain suggests that residents of non-SMSA areas were more likely to tolerate pain without seeking care. These findings underscore the need for proper behavioral and pain management during childhood.

Adult↗
PubMed1999

Electromotive drug administration of lidocaine as an alternative anesthesia for transurethral surgery.

PURPOSE: A multicenter study was undertaken to evaluate the safety, efficacy and cost of electromotive drug administration of intravesical lidocaine to produce bladder local anesthesia as an alternative to traditional methods of spinal or general anesthesia. MATERIALS AND METHODS: A total of 94 patients were enrolled in the study who had either a history of bladder tumor that required cold cup bladder biopsy with fulguration for possible recurrence as a comparison trial, a bladder tumor treated with transurethral resection/fulguration or benign prostatic hyperplasia/carcinoma treated with transurethral resection. Pain scores using a Verbal Rating Scale were recorded for each individual biopsy, fulguration and resection event. Data for direct and indirect costs were collected using a standardized form for each patient to capture the details of the procedure, including times, drugs and disposables for each patient. RESULTS: There was a significant reduction in pain for patients who received electromotive intravesical lidocaine compared to no anesthesia for biopsy (p<0.03). Similarly, electromotive intravesical lidocaine for bladder biopsy and transurethral bladder tumor resection/fulguration was associated with higher patient satisfaction compared to previous treatments (p<0.00002). In contrast, electromotive intravesical lidocaine was insufficient for 3 of 6 transurethral prostatic resections. The cost per patient was about $146 Cdn less with electromotive intravesical lidocaine than with conventional general/spinal anesthesia. CONCLUSIONS: Electromotive intravesical lidocaine may be a safe, effective and affordable form of anesthesia for the ambulatory care of patients requiring transurethral bladder biopsy, resection or fulguration with a potential for cost savings.

Aged↗
PubMed1998

Hereditary febrile seizures: phenotype and evidence for a chromosome 19p locus.

The occurrence of febrile seizures (FSs) in large autosomal dominant FS kindreds makes possible accurate delineation of the pure clinical phenotype of hereditary FS among secondary FS cases, and the identification of gene loci causing susceptibility to FS. Recently FS gene loci on chromosomes 8 and 19 were identified. We studied the phenotype of FS in four large families in which FS is an autosomal dominant trait. Among 30 affected secondary FS cases, mean age of onset was 16.3 months (range 4 to 36 months), sex ratio was equal, and 43% were complex (13 of 30). Among these 30 secondary FS cases, the mean number of FSs was 2.1, half had only a single FS, and none had afebrile seizures. Penetrance was 0.67, approximately the same as in our previous larger group of 40 multicase FS families (0.64). The occurrence of DPT encephalopathy in a sib of a patient with FS raises the possibility that these two etiologies are related. Linkage studies showed that one of the four families (Family 1) was linked to chromosome 19p markers, none of the families was linked to chromosome 8q markers, and the largest FS family (Kindred 6) was unlinked to either 19p or 8q markers, supporting the hypothesis of genetic heterogeneity for FS.

Chromosomes, Human, Pair 19↗
PubMed1998

Salt wars.

Explore the source record for details and available documents.

Blood Pressure↗