Biomedical subjects
Publications and source records attributed to S Katz.
Surgical management of chronic otitis media with effusion. One hundred and twenty six children suffering from chronic otitis media with effusion (OME) were operated. Ninety two point eight percent had a satisfactory outcome. Surgical management of chronic OME is discussed.
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OBJECTIVES: Reports of Crohn's disease (CD)-associated colorectal carcinoma are being cited in the medical literature with increasing frequency. Our aim was to identify subgroups of patients with risk factors that may account for this. METHODS: We reviewed the medical records of 16 patients with the simultaneous diagnosis of CD and colorectal carcinoma and, in addition, reviewed previously reported cases of CD-associated colorectal carcinoma. RESULTS: Eight male and eight female patients presented with 18 carcinomas: four right colon, four transverse, two descending colon, and eight rectal lesions. Median age at presentation was 48 yr. The mean duration of CD before presentation of carcinoma was 19.7 yr. Two lesions were discovered in strictured bowel segments. Two patients had multiple cancers. One had simultaneous cecal and left colon adenocarcinomas. The other underwent resection of a right colon lesion and 5 yr later presented with transverse colon carcinoma. Eight patients had rectal cancer; all were diagnosed preoperatively. Six of these patients had a history of severe perianal CD. Six had undergone multiple incision and drainage procedures for perirectal abscesses and fistulas. Two developed malignancies in defunctionalized rectal stumps. One of these patients presented with simultaneous squamous rectal carcinoma and papillary bile duct cholangiocarcinoma. CONCLUSIONS: Gastrointestinal malignancy in association with CD has been reported. Symptoms of chronic inflammatory disease may obscure clinical manifestations of occult malignancy and thereby delay diagnosis. Crohn's patients with long-standing anorectal or perianal disease and stricture may well warrant surveillance endoscopy and biopsy of involved areas with the hope of earlier detection and treatment of these rectal cancers.
Our experience with 11 cases of cystic dilation of the biliary tract is reported. 10 children with choledochal cyst were treated by cystduodenostomy (5 cases) and excision of the cyst with hepaticojejunostomy (5 cases). 1 patient who presented with Caroli's disease was not operated. At long term follow-up, all patients except 1 are asymptomatic. A 16-year-old girl who presented with acute pancreatitis 13 years following cystduodenostomy, early in our experience, underwent excision of the choledochal cyst and hepaticojejunostomy, with uneventful postoperative course. We conclude that in the era of modern imaging, accurate preoperative diagnosis may contribute to better planning and outcome of the surgical treatment of these relatively rare congenital biliary anomalies.
The differential diagnosis between intrahepatic and extrahepatic cholestasis in the newborn is difficult and has therapeutic implications. 61 cases of neonatal cholestasis were retrospectively analyzed to assess the efficacy of various tests and procedures in differentiating between the 2 types. Determination of serum gamma-glutamyl transpeptidase, ultrasonography and radionuclide scanning differed significantly in the 2 types (p '0.05 for all 3 determinations). A diagnostic program for evaluation of infants with neonatal cholestasis is proposed.
Certain cells present in mouse skin are resistant to calcium-induced terminal differentiation. It is believed that these calcium-resistant cells (CRCs) represent an early stage in the carcinogenic process, in part, because frequency increases after treatment with mutagens. The frequency of CRCs in C3H mouse skin was measured before and after treatment with certain petroleum-derived materials. One objective was to determine whether this assay could differentiate between genotoxic and nongenotoxic mouse skin carcinogens. An additional objective was to determine whether CRCs are an important factor in the tumorigenicity of petroleum middle distillates (PMDs), a class of apparently nongenotoxic mateials. Three petroleum-derived materials were tested: mineral oil (MO), a noncarcinogenic product used as the negative control; catalytically cracked clarified oil (CCCO), a highly carcinogenic and mutagenic material; and a lightly paraffinic (LRPO), a PMD which has produced tumors when repeatedly applied, but is not mutagenic and does not initiate most skin tumors. The CRC frequency was not increased by LRPO treatment; however, a statistically significant and dose-related increase was produced by CCCO. These results are consistent with observations that genotoxic, petroleum-derived liquids are capable of tumor initiation in mouse skin, whereas PMDs which are not genotoxic do not initiate skin tumors. The number of CRCs in untreated and MO-treated mice was approximately twice the tumor frequency measured in bioassays of PMDs. Thus, tumor production associated with these products could be due to promotion of preexisting, spontaneously initiated cells.
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The laryngeal mask airway (LMA) was recently introduced in pediatric anesthesia as an alternative to the face mask or tracheal intubation for airway maintenance. The authors report their experience with LMA on 120 consecutively treated children who underwent elective inguinal herniorrhaphy or orchidopexy. The patients were monitored with electrocardiograms, noninvasive blood pressure determinations, pulse oxymetry, and capnometry. Anesthesia was induced and maintained with halothane, nitrous oxide, and oxygen. There were 96 males and 24 females; the age range was 1 month to 14 years (average, 3.2 years). They weighed between 2.5 and 46 kg (mean, 14 kg). Patients were allowed to breath spontaneously until anesthesia was deep enough (average, 6.3 minutes; range, 2 to 15 minutes). The appropriate-size LMA was inserted and inflated, and patients were divided into three groups. Group I patients (n = 24) weighed 2.6 to 6 kg and received LMA size no. 1. Group II (n = 84) weighed 6 to 30 kg and received LMA size no. 2. Group III (n = 12) weighed more than 30 kg and received LMA size no. 3. Patients in groups II and III breathed spontaneously; those in group I were on volume-controlled ventilation. The LMA was easily inserted in 115 patients (95.8%)--on the first attempt in 100, and on the second attempt in 15. In five patients, LMA was successfully inserted on the third attempt. The ease of insertion was not significantly different between the groups. Anesthesia was maintained by halothane (mean, 1.34%; range, 0.8% to 2.54%) for an average of time of 39.2 minutes (range, 15 to 90 minutes).(ABSTRACT TRUNCATED AT 250 WORDS)
Inositol 1,4,5-trisphosphate (IP3)-, GTP-, arachidonic acid- and thapsigargin-mediated Ca2+ release from endoplasmic reticulum (ER)-enriched microsomes was studied in a PANC-1 cell line. IP3 maximally caused an approximately 20% release of actively accumulated Ca2+. This effect was completely blocked by heparin. In the presence of 3% polyethylene glycol (PEG), GTP maximally discharged about 60% of Ca2+ from the microsomes. This effect involved a GTP hydrolytic process, not the IP3-activated Ca2+ channel. Arachidonic acid maximally released approximately 80% of Ca2+ from PANC-1 microsomes. Metabolites of arachidonic acid did not appear to be involved in arachidonic acid-mediated Ca2+ release. However, other fatty acids also induced similar releasing effects suggesting that arachidonic acid-induced Ca2+ release appeared to be non-specific. Thapsigargin was shown to inhibit Ca2+ accumulation into and induce Ca2+ release from PANC-1 microsomes. The thapsigargin-releasable Ca2+ pool included the IP3- or arachidonic acid-sensitive pool. Studies on liposomes suggested that both arachidonic acid and thapsigargin did not exert either a Ca2+ ionophore-like or a membrane detergent-like effect. The present results have provided evidence for the existence of multiple non-mitochondrial Ca2+ pools in PANC-1 cells. These Ca2+ pools could be released by various Ca2+ mediators via different mechanisms.
This paper describes a two year holistic transition programme for persons with a learning disability in Israel and a follow-up of the first cohort of trainees. The programme which was initiated by the National Insurance Institution and 'Nitzan' a parent voluntary organization was developed to provide these persons with the vocational, personal and social skills required for successful independent living and vocational adjustment. The training was carried out in a residential setting and included vocational training, activities of daily living, educational activities and personal adjustment counselling. The results indicated that two years after completing the programme the trainees were generally meeting the expectations of the goals of the project.
Necrotizing pneumonia, massive necrosis of lung tissue, is a serious, often fatal, complication of lobar pneumonia. Four children 1.3 to 7.5 yr of age were hospitalized with bacteremic pneumococcal pneumonia. All of them were acutely ill on presentation with arterial desaturation, and they developed anemia and thrombocytosis. Two patients had pleural effusion requiring drainage. A chest CT scan revealed segmental or lobar pulmonary liquification, which led to the diagnosis of necrotizing pneumonia. This finding could be demonstrated early in the course of the disease. Subsequently, all of the patients developed cavitating lesions. With adequate antipneumococcal therapy and/or chest tube drainage, all of the patients recovered completely; however, clinical improvement was prolonged: fever lasted 9 to 20 days, and length of hospitalization was 12 to 26 days. Contrary to that in adults, complete recovery is anticipated in children with bacteremic necrotizing pneumococcal pneumonia, and no invasive investigations are required.
Previous work has shown that the scaling of mechanical behaviour in bending of the metathoracic tibiae of the African desert locust (Schistocerca gregaria) is not predicted by the scaling of external dimensions. The flexural stiffness of the tibia scales to (body mass)1.53, which is similar to the predictions of the elastic similarity model of scaling. The external dimensions, however, scale in a manner that produces relatively more elongate limb segments ­ an observation that differs from the predictions of any existing scaling model. In this paper, we examined two alternative hypotheses to explain this uncoupling of morphology and mechanics: (1) that the load-bearing cuticular material is distributed in the legs in a manner that is not indicated by changes in external dimensions, or (2) that the stiffness of the cuticular material is altered to produce the observed scaling of flexural stiffness. The second moment of area (I) scaled to (body mass)1.19, which was similar to scaling I to (tibial radius)4. This indicates that the relationship between the external dimensions of the tibiae and the specific distribution of load-bearing material is conserved independently of scale. Therefore, the locust achieves the observed scaling of flexural stiffness by altering the modulus of the load-bearing cuticular material. In fact, the time-dependent modulus (E') scales to (body mass)0.311. In essence, the scaled material stiffness provides a degree of freedom in design in addition to external morphological dimensions in accommodating the changing demands placed on a skeletal structure with increases in body size.
The ventilatory patterns of air-breathing fish are commonly described as 'arrhythmic' or 'irregular' because the variable periods of breath-holding are punctuated by seemingly unpredictable air-breathing events (see Shelton et al. 1986). This apparent arrhythmicity contrasts with the perceived periodism or regularity in the gill ventilation patterns of some fish and with lung ventilation in birds and mammals. In this sense, periodism refers to behaviour that occurs with a definite, recurring interval (Bendat and Piersol, 1986). The characterisation of aerial ventilation patterns in fish as 'aperiodic' has been generally accepted on the basis of qualitative examination and it remains to be validated with rigorous testing. The bowfin, Amia calva (L.), is a primitive air-breathing fish that makes intermittent excursions to the air­water interface to gulp air, which is transferred to its well-vascularized gas bladder. Its phylogenetic position as the only extant member of the sister lineage of modern teleosts affords a unique opportunity to examine the evolution of aerial ventilation and provides a model for the examination of ventilatory patterns in primitive fishes. To establish whether Amia calva exhibit a particular pattern of air-breathing, we examined time series records of aerial ventilations from undisturbed fish over long periods (8 h). These records were the same as those used to calculate average ventilation intervals under a variety of experimental conditions (Hedrick and Jones, 1993). Their study also reported the occurrence of two distinct breath types. Type I breaths were characterised by an exhalation followed by an inhalation, whereas type II breaths were characterised by inhalation only. It was also hypothesized that the type I breaths were employed to meet oxygen demands, whereas the type II breaths were used to regulate gas bladder volume. However, they did not investigate the potential presence of a periodic ventilatory pattern. We now report the results of just such an analysis of ventilatory pattern that demonstrates a clear periodism to air-breathing in a primitive fish.
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