Search PubMed⌕ Search

Biomedical subjects

J Katz

Publications and source records attributed to J Katz.

At least 73 records · Page 4Linked to original sources
PubMed2001

Stafne's bone cavity in the anterior mandible: a possible diagnostic challenge.

Stafne was the first to report the presence of "bone cavities" in the angle of 35 mandibles. Such cavities generally appear in the area between the mandibular first molar and the mandibular angle, and are not considered rare. One of their primary radiological diagnostic features is the characteristic location below the mandibular canal. Stafne's bone cavity is relatively rare in the anterior mandible. The mandibular canal is not present in the anterior mandible. As a result, diagnosis in the anterior mandible may be missed. Needless treatment modalities such as endodontic treatment, bone trephining, and bone exploration may be conducted. The purpose of the present report is to describe a new case of Stafne's bone cavity in the anterior mandible and discuss the differential diagnosis process. The dental computerized tomography scan is suggested as the most suitable noninvasive diagnostic and follow-up modality for this bony configuration in the anterior mandible.

Diagnosis, Differential↗
PubMed2001

Difficult airway in obstetric anesthesia: a review.

UNLABELLED: Failed intubation and ventilation are important causes of anesthetic-related maternal mortality. The purpose of this article is to review the complex issues in managing the difficult airway in obstetric patients. The importance of prompt and competent decision making in managing difficult airways, as well as a need for appropriate equipment is emphasized. Four case reports reinforce the importance of a systematic approach to management. The overall preference for regional rather than general anesthesia is strongly encouraged. The review also emphasizes the need for professional and experienced team cooperation between the obstetrician and the anesthesiologist for the successful management of these challenging cases. LEARNING OBJECTIVES: After completion of this article, the reader will be able to break down the complex issues in managing the difficult airway in the obstetric patient, outline the reasons for difficult intubations in pregnancy, and describe the evaluation used to predict a difficult intubation.

Adult↗
PubMed2001

Pneumococcal nasopharyngeal colonization in young South Indian infants.

BACKGROUND: Streptococcus pneumoniae is the most frequent bacterial cause of morbidity and mortality in young children. Bacteria carried in the nasopharynx of healthy children reflect the prevalent strains circulating in the community. METHODS: We recruited 464 newborns from a rural area in South India with endemic vitamin A deficiency. Nasopharyngeal specimens were collected from each infant at ages 2, 4 and 6 months. RESULTS: Fifty-four percent of study infants were colonized by age 2 months, with 64.1 and 70.2% carriage prevalence at ages 4 and 6 months, respectively. The odds of carriage at 2 months were significantly increased in female infants, infants living in a household in which 20 or more cigarettes were smoked each day, infants whose mothers had less than 1 year of schooling and infants fed colostrum. At age 4 months infants having 2 or more siblings <5 years of age were at significantly increased risk of carriage. At age 6 months none of the potential risk factors examined achieved statistical significance, but maternal night blindness increased the risk of colonization 3-fold. The odds of carrying a PncCRM197 vaccine serotype were increased among infants born to mothers who experienced night blindness during pregnancy. The most prevalent serogroups/types during the first 6 months of life were 6, 9, 10, 11, 14, 15, 19, 23 and 33, accounting for 76.7% of all serotyped isolates. CONCLUSIONS: South Indian infants experience high rates of pneumococcal carriage during the first 6 months of life, which may partially explain their increased risk for pneumonia.

Age Factors↗
PubMed2001

Superior vena cava syndrome following neonatal cardiac surgery.

OBJECTIVE: To review the incidence, diagnosis, and management of superior vena cava syndrome (SVCS) after surgery for congenital heart disease. DESIGN: Retrospective clinical review. All patients were computer registered. Our database includes daily follow-up. SETTING: Pediatric cardiac surgery intensive care unit in a university hospital. PATIENTS: A total of 1853 consecutive pediatric cardiac operations performed in 285 neonates and 1568 older children from 1993 to 1999 are reviewed. MEASUREMENTS AND MAIN RESULTS: The diagnosis of SVCS was suspected clinically: Color changes and swelling of the upper part of the body, confirmed by echo-Doppler, showed no or minimal flow in the superior vena cava at the beginning and collateral flow later on. Nine patients developed SVCS (0.5%). All the study patients were neonates. The prevalence of SVCS in our neonatal patients was 3.15% (nine of 285), with no SVCS in older children. Accompanying complications included chylothorax (five), hydrocephalous (four)-three of whom required ventriculoperitoneal shunt during follow-up. Thrombolytic therapy was used in five patients, and thrombectomy was used in one patient. The ventilation period ranged from 4 to 46 days (mean 20.1 days), and the length of hospital stay ranged from 37 to 120 days (mean 61.3 days). No mortality was observed during follow-up. CONCLUSIONS: SVCS is an uncommon, severe complication following neonatal cardiac surgery. It may cause chylothorax, hydrocephalus, and severe respiratory complications leading to high morbidity. Early diagnosis and thrombolytic therapy may prevent the progression of this syndrome to its subsequent sequels.

Journal Article↗
PubMed2001

Central neuroplasticity and pathological pain.

The traditional specificity theory of pain perception holds that pain involves a direct transmission system from somatic receptors to the brain. The amount of pain perceived, moreover, is assumed to be directly proportional to the extent of injury. Recent research, however, indicates far more complex mechanisms. Clinical and experimental evidence shows that noxious stimuli may sensitize central neural structures involved in pain perception. Salient clinical examples of these effects include amputees with pains in a phantom limb that are similar or identical to those felt in the limb before it was amputated, and patients after surgery who have benefited from preemptive analgesia which blocks the surgery-induced afferent barrage and/or its central consequences. Experimental evidence of these changes is illustrated by the development of sensitization, wind-up, or expansion of receptive fields of CNS neurons, as well as by the enhancement of flexion reflexes and the persistence of pain or hyperalgesia after inputs from injured tissues are blocked. It is clear from the material presented that the perception of pain does not simply involve a moment-to-moment analysis of afferent noxious input, but rather involves a dynamic process that is influenced by the effects of past experiences. Sensory stimuli act on neural systems that have been modified by past inputs, and the behavioral output is significantly influenced by the "memory" of these prior events. An increased understanding of the central changes induced by peripheral injury or noxious stimulation should lead to new and improved clinical treatment for the relief and prevention of pathological pain.

Afferent Pathways↗
PubMed2001

An enzyme-linked immunosorbent assay for the convenient serodiagnosis of contagious equine metritis in mares.

An enzyme-linked immunosorbent assay (ELISA) was developed for the serodiagnosis of contagious equine metritis (CEM), a sexually transmitted disease caused by Taylorella equigenitalis. Antigen preparation was simple, and antigens derived from both classical and atypical forms of T. equigenitalis enabled detection of antibody responses elicted in horses experimentally exposed to either form of the bacterium. Sera serially obtained from these horses from 0 to 63 days postexposure were tested by the traditional complement fixation test (CFT) for CEM and with the ELISA, using both antigens separately. There was close agreement between CFT and ELISA methodologies during the postexposure time period used to detect CEM serodiagnostically in regulatory animal health testing programs. Unlike the CFT, which requires an overnight incubation step, the ELISAs are more convenient and can be completed in 3 hours.

Animals↗
PubMed2001

A vaccine against dental caries: an overview.

Dental caries continues to be a costly and prevalent oral disease. Research efforts towards developing a well tolerated and effective vaccine against dental caries were initiated following the demonstration of a specific bacterial aetiology for this disease. The cariogenic mutans streptococci are the principal bacteria causing this disease. Specific immune defence against these bacteria is provided mainly by secretory immunoglobulin (Ig) A antibodies present in saliva, which are generated by the common mucosal immune system. Progress in the development of a vaccine against dental caries has increased due to both advancements in molecular biology and our understanding of the mucosal immune system and mucosal vaccines. Advancements in molecular biology have facilitated the cloning and functional characterisation of virulence factors of the mutans streptococci, including the cell-surface fibrillar proteins, which mediate adherence to the tooth surface, and the glucosyltransferase enzymes, which synthesise adhesive glucans and allow microbial accumulation on the teeth. Current strategies for immunisation against dental caries are using these virulence factors as key antigens and incorporating them into novel mucosal vaccine systems and delivering them with or without adjuvants to mucosal IgA inductive sites. The most popular routes of mucosal immunisation are via the oral or nasal route. The mucosal immune system is functional in newborn infants, who develop salivary IgA antibodies as they become colonised by oral micro-organisms. Mucosal immunisation strategies result in the induction of salivary IgA antibody responses and pose fewer problems than parenteral injection of antigen. Therefore, mucosal immunisation of infants prior to the appearance of their first teeth may be a well tolerated and effective way to induce immunity against the colonisation of teeth by mutans streptococci and protection against subsequent dental caries. The purpose of this article is to provide an overview of the recent progress on the development of a vaccine against infection by Streptococcus mutans for the prevention of dental caries, with emphasis on the mucosal immune system and vaccine design.

Animals↗
PubMed2001

Update on the evaluation and therapy of autoimmune neuromuscular junction disorders.

Many recent strides have increased our understanding of the immune-mediated diseases of neuromuscular junction transmission. Nevertheless, patients with myasthenia gravis and the Lambert-Eaton myasthenic syndrome often present diagnostic and therapeutic challenges to clinicians. Both conditions have a wide range of clinical presentations and the number of treatment modalities available to these patients continues to increase. This creates a need for an individualized approach for managing these patients. Other important controversies exist because the benefits of some treatments are not firmly established by clinical trials. After a brief review of the pertinent scientific basis of these diseases, we focus on present issues governing the clinical evaluation and management of myasthenia gravis and the Lambert-Eaton myasthenic syndrome.

Autoimmune Diseases↗
PubMed2001

A postoperative prognostic nomogram for renal cell carcinoma.

PURPOSE: Few published studies have combined prognostic factors to predict the likelihood of recurrence after surgery for renal cell carcinoma. We developed a nomogram for this purpose. MATERIALS AND METHODS: With Cox proportional hazards regression analysis, we modeled pathological data and disease followup for 601 patients with renal cell carcinoma who were treated with nephrectomy. Predictor variables were patient symptoms, including incidental, local or systemic, histology, including chromophobe, papillary or conventional, tumor size, and pathological stage. Treatment failure was recorded when there was either clinical evidence of disease recurrence or death from disease. Validation was performed with a statistical (bootstrapping) technique. RESULTS: Disease recurrence was noted in 66 of the 601 patients, and those in whom treatment was successful had a median and maximum followup of 40 and 123 months, respectively. The 5-year probability of freedom from failure for the patient cohort was 86% (95% confidence interval 82 to 89). With statistical validation, predictions by the nomogram appeared accurate and discriminating with an area under the receiver operating characteristic curve, that is a comparison of the predicted probability with the actual outcome of 0.74. CONCLUSIONS: A nomogram has been developed that can be used to predict the 5-year probability of treatment failure among patients with newly diagnosed renal cell carcinoma. The nomogram may be useful for patient counseling, clinical trial design and patient followup planning.

Carcinoma, Renal Cell↗
PubMed2000

Night blindness during pregnancy and subsequent mortality among women in Nepal: effects of vitamin A and beta-carotene supplementation.

Night blindness due to vitamin A deficiency is common during pregnancy among women in Nepal. The authors assessed the risk of maternal death during and after a pregnancy with night blindness among women participating in a cluster-randomized, placebo-controlled vitamin A and beta-carotene supplementation trial in Nepal from July 1994 to September 1997. Subjects were 877 women with night blindness and 9,545 women without night blindness during pregnancy. Women were followed from the time they declared that they were pregnant through the end of the study, representing a median follow-up of 90 weeks (interquartile range: 64-121 weeks). Mortality of night-blind women in the placebo group was 3,601 per 100,000 pregnancies. In comparison, the relative risk of dying among nonnight-blind women in the placebo group was 0.26 (95% confidence interval (CI): 0.13, 0.55), and the relative risk among women with or without night blindness in the vitamin A/beta-carotene group was 0.32 (95% CI: 0.10, 0.91) and 0.18 (95% CI: 0.09, 0.36), respectively. Night-blind women were five times (95% CI: 2.20, 10.58) more likely to die from infections than were women who were not night blind. These findings show that night blindness during pregnancy is a risk factor of both short- and long-term mortality among women. Vitamin A/beta-carotene supplementation ameliorates this risk to a large extent.

Adolescent↗
PubMed2000

Second primary malignancies associated with renal cell carcinoma: influence of histologic type.

OBJECTIVES: This study was performed to determine which histologic types of renal cell carcinoma have an association with a second primary malignancy. METHODS: Seven hundred sixty-three patients underwent an operation for renal cell carcinoma between July 1989 and January 1999. The incidence of antecedent, synchronous, or subsequent second malignancies was determined. Statistical tests based on the Poisson model were used to compare the observed number of subsequent malignancies developing after a diagnosis of renal cell carcinoma with the expected number calculated using the 1973 to 1994 U.S. Surveillance, Epidemiology, and End Results age, race, gender, and calendar-year specific incidence rates. RESULTS: Second primary malignancies were present in 209 of 763 (27.4%) patients, with prostate, breast, colon, and bladder cancer and non-Hodgkin's lymphoma being the five most common second malignancies. The other malignancies were antecedent in 118 cases (44.5%), synchronous in 104 cases (39.2%), and subsequent in 43 cases (16.2%). Patients with papillary renal cell carcinoma were at increased risk of developing bladder cancer (standardized incidence ratio [SIR] 6.5, P = 0.038). Men with papillary renal cell carcinoma were also at increased risk of developing prostate cancer (SIR 2.8, P = 0.035). CONCLUSIONS: There is an increased risk of subsequent bladder and prostate cancer in patients with papillary renal cell carcinoma.

Adolescent↗
PubMed2000

Pneumocystis carinii mutations are associated with duration of sulfa or sulfone prophylaxis exposure in AIDS patients.

This study was conducted to determine whether Pneumocystis carinii dyhydropteroate synthase (DHPS) gene mutations in AIDS patients with P. carinii pneumonia (PCP) are affected by duration of sulfa or sulfone prophylaxis and influence response to sulfa or sulfone therapy. The P. carinii DHPS genes from 97 AIDS patients with PCP between 1991 and 1999 from 4 medical centers were amplified, using polymerase chain reaction (PCR), and sequenced. Mutations were observed in 76% of isolates from patients exposed to sulfa or sulfone prophylaxis compared with 23% of isolates from patients not exposed (P=.001). Duration of prophylaxis increased the risk of mutations (relative risk [RR] for each exposure month, 1.06; P=.02). Twenty-eight percent of patients with mutations failed sulfa or sulfone treatment; mutations increased the risk of sulfa or sulfone treatment failure (RR, 2.1; P=0.01). Thus, an increased duration of sulfa or sulfone prophylaxis increases the chance of developing a P. carinii mutation. The majority of patients with mutations respond to sulfa or sulfone therapy.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Patterns of detection in patients with cutaneous melanoma.

BACKGROUND: Despite the importance of early detection in preventing mortality from melanoma, little is known regarding how patients with the disease come to diagnosis. METHODS: The authors prospectively evaluated 471 newly diagnosed melanoma patients between 1995 and 1998. Patients completed a questionnaire that included 1) identification of the person who detected the lesion, 2) the anatomic location of the lesion, and 3) family history of melanoma. Logistic regression analysis was performed to examine the relation between detection patterns and lesion thickness, adjusting for age, gender, anatomic site of the primary lesion, and family history of melanoma. RESULTS: The majority of patients detected their own melanoma (n = 270; 57%). Females were more likely to self-detect than males (69% vs. 47%; P < 0.0001). Physicians detected the melanoma in 16% of patients (n = 74), followed by "spouse" in 11% of patients (n = 51). Within this group, detection by wives was 7.5 times more common than detection by husbands (P < 0.0001). Logistic regression analysis revealed that physicians were 3.6 times more likely to detect thin lesions (</=0.75 mm) compared with nonphysician detectors (95% confidence interval [95% CI], 2.1, 6.5; P = 0.0001). In addition, patients who reported a family history of melanoma had a 2.7-fold increased likelihood of presenting with a thin lesion (95% CI, 1.6, 4.7; P = 0.0003). CONCLUSIONS: Physician detection and a report of a family history of melanoma are associated with the presentation of patients with early melanoma, suggesting that awareness of the disease among physicians and the public is critical for preventing mortality from melanoma. Increasing melanoma awareness in males may be a particularly effective means of secondary prevention.

Adult↗
PubMed2000

The value of routine preoperative medical testing before cataract surgery. Study of Medical Testing for Cataract Surgery.

BACKGROUND: Routine preoperative medical testing is commonly performed in patients scheduled to undergo cataract surgery, although the value of such testing is uncertain. We performed a study to determine whether routine testing helps reduce the incidence of intraoperative and postoperative medical complications. METHODS: We randomly assigned 19,557 elective cataract operations in 18,189 patients at nine centers to be preceded or not preceded by a standard battery of medical tests (electrocardiography, complete blood count, and measurement of serum levels of electrolytes, urea nitrogen, creatinine, and glucose), in addition to a history taking and physical examination. Adverse medical events and interventions on the day of surgery and during the seven days after surgery were recorded. RESULTS: Medical outcomes were assessed in 9408 patients who underwent 9626 cataract operations that were not preceded by routine testing and in 9411 patients who underwent 9624 operations that were preceded by routine testing. The most frequent medical events in both groups were treatment for hypertension and arrhythmia (principally bradycardia). The overall rate of complications (intraoperative and postoperative events combined) was the same in the two groups (31.3 events per 1000 operations). There were also no significant differences between the no-testing group and the testing group in the rates of intraoperative events (19.2 and 19.7, respectively, per 1000 operations) and postoperative events (12.6 and 12.1 per 1000 operations). Analyses stratified according to age, sex, race, physical status (according to the American Society of Anesthesiologists classification), and medical history revealed no benefit of routine testing. CONCLUSIONS: Routine medical testing before cataract surgery does not measurably increase the safety of the surgery.

Aged↗
PubMed2000

Personality features differentiate late adolescent females and males with chronic bulimic symptoms.

OBJECTIVE: The authors examined gender differences in bulimia-related personality variables among late adolescents with chronic bulimic symptoms. METHOD: Ninety-seven females and 14 males were included in the study. They participated in surveys in 1982, and again in 1992, and at each session reported elevated bulimic symptoms. Each respondent completed subscales of the Eating Disorders Inventory (Bulimia, Drive for Thinness, Perfectionism, and Interpersonal Distrust). RESULTS: Even compared to males with similar levels of chronic bulimic symptoms, females with chronic bulimic symptoms reported more drive for thinness; compared to females with chronic bulimic symptoms, males with chronic bulimic symptoms reported more perfectionism and interpersonal distrust. DISCUSSION: Late adolescent males and females with chronic bulimic symptoms can be distinguished on the basis of personality features. These findings have implications for theory, as well as for clinical assessment and therapeutics.

Adolescent↗