PubMed Health⌕ Search

Biomedical subjects

J Chernin

Publications and source records attributed to J Chernin.

16 recordsLinked to original sources
PubMed2000

Perioperative extracorporeal membrane oxygenation for tracheal reconstruction in congenital tracheal stenosis.

The management of a critical airway in infants and toddlers with congenital tracheal stenosis (CTS) continues to be an enormous challenge to the surgeon. Until recently, this condition often proved fatal. Improvements in surgical techniques, anesthetic management, and postoperative critical care have resulted in successful outcomes in children not long ago considered untreatable. However, issues such as the best operative approach and the optimal perioperative management are still unresolved. The diagnosis of CTS, often delayed, must be considered in any infant with stridor, wheezing, cyanosis, or recurrent episodes of pneumonia. Associated anomalies are the rule, including frequently vascular rings and rarely pulmonary agenesis. These defects can be repaired with conventional ventilatory support under cardiopulmonary bypass, or using extracorporeal membrane oxygenation (ECMO). We report our experience in which ECMO was used to support two patients with CTS during the perioperative period. ECMO proved to be both safe and practical, allowing unrushed, precise repair of the tracheal stenosis and providing brief postoperative support. Perioperative outcomes were excellent, although one of our patients died months after the repair. A review of the literature and our experience in which ECMO was used to provide cardiopulmonary support during repair of CTS showed uniformly successful perioperative outcomes.

Extracorporeal Membrane Oxygenation↗
PubMed2000

Use of L4 larvae of Nippostrongylus brasiliensis for the in vivo screening of anthelmintic drugs.

Five groups of Wistar rats were subcutaneously infected with 5,000 L3 stage larvae of Nippostrongylus brasiliensis. Four groups were dosed orally with 5, 10, 15, and 20 mg/kg body weight of albendazole at 5 h postinfection, and one group served as an untreated control. The animals were euthanized and the intestines were dissected out 72 h postinfection and were incubated on a Baermann's apparatus to recover L4 stage larvae. No larvae were recovered from the 20 mg/kg albendazole-treated group, and means of 15, 33, and 175 L4 larvae were recovered from the 15, 10, and 5 mg/kg albendazole-treated groups, respectively. Levamisole and fenbendazole were also tested using the same procedure. Means of 100 and 1,887 L4 larvae were obtained from the 50 and 10 mg/kg of levamisole-treated groups respectively; while, 191 and 583 L4 larvae were recovered from rats treated with 50 and 10 mg/kg of fenbendazole, respectively. These results indicate that the L4 stage of N. brasiliensis could be useful for in vivo screening of new nematocide drugs.

Animals↗
PubMed1994

The effect of the tetrathyridia of Mesocestoides corti on the livers and peripheral blood of three different strains of mice.

Three strains of male and female mice, CFLP, BALB/c and CBA/ca, were infected i.p. with the tetrathyridia of Mesocestoides corti and examined in groups of 5 at 0, 7, 14, 21, 28 and 42 days post-infection. At post-mortem the numbers of parasites both loose in the peritoneal cavity and in the liver tissue were counted, the livers weighted fresh and sections of liver stained to examine the inflammatory response, encapsulation of the tetrathyridia and for eosinophils, neutrophils, mast cells and plasma cells. BALB/c mice had significantly more parasites loose in the peritoneal cavity than CFLP and CBA/ca mice. Infected livers of all three strains were significantly heavier than control livers; the heaviest livers were those of the CFLP followed by the CBA/ca mice which also showed the greatest rate of weight increase. The tetrathyridia from the peritoneal cavities of the CBA/ca and CFLP mice were covered with a 'mucilage-like' substance. Tetrathyridia within the host capsules of the CBA/ca mice contained host cells. There was no strain difference with regard to numbers of tetrathyridia in the liver but male mice harboured significantly more parasites than females. Differences in the numbers of cell types within the liver were detected between the strains but no one strain showed any consistent pattern. There was an overall increase in total white blood counts as well as an increase in the number of eosinophils, monocytes, neutrophils and lymphocytes during the course of the infection.

Animals↗
PubMed1988

Mesocestoides corti: parameters of infection in CBA/Ca mice and the effect of introducing a concomitant trematode infection.

CBA/Ca mice infected with the tetrathyridia of Mesocestoides corti were exposed to Schistosoma mansoni cercariae either simultaneously, or at varying intervals after the initial M. corti infection. Cohorts were infected with either parasite alone. The dual infected mice and the mice harbouring M. corti alone were significantly heavier than either naive controls or mice carrying the S. mansoni infection only. The livers and spleens from dual infection mice were also found to be significantly heavier than those from other groups. Free M. corti tetrathyridia were reduced in number in the peritoneal cavity of dual infected mice, as compared with mice harbouring a single infection. Furthermore, the intensity of the initial M. corti infection, as measured by the number of capsules surrounding parasites in the liver, was reduced when the mice experienced an S. mansoni infection 21 days later. The mice which were exposed to M. corti only exhibited more mast cells and eosinophils around encapsulated tetrathyridia in the liver than did dual infection mice, while cells surrounding S. mansoni egg granulomas in the liver were significantly increased in dual infection mice. An increase in serum alkaline phosphatase levels was detected in both the mice receiving the dual infection and the mice with the S. mansoni only infection, but not in mice harbouring M. corti alone.

Alkaline Phosphatase↗
PubMed1988

Cytotoxic activity of rat granulocytes against Mesocestoides corti.

Rat eosinophils or neutrophils were purified from peritoneal washings which had been enriched either for eosinophils by infection with the parasite Mesocestoides corti or by intravenous injection with Sephadex G200 particles, or for neutrophils by the intraperitoneal injection of glycogen. Neither eosinophils nor neutrophils attached to or damaged live M. corti parasites in vitro although they did lyse chick erythrocytes in the presence of rat anti-chick red blood cell antibody, with the neutrophils showing the highest level of cytotoxicity and the eosinophils from the infected rats the lowest. Neutrophils gave a specific antibody-dependent cytotoxic response to chick erythrocytes coated with solubilized M. corti extract, a response not seen with eosinophils. The cytotoxicity shown by neutrophils could not be blocked by adding eosinophils or sera obtained from chronically infected rats although it was reduced by incubating the neutrophils with cell-free supernatants obtained from the spleen cells of infected rats following stimulation with solubilized parasite extract in vitro. Eosinophils from infected rats expressed fewer membrane Fc receptors for antibody than did neutrophils or eosinophils from uninfected animals. Incubation of neutrophils and eosinophils from uninfected rats with the immune spleen cell supernatants reduced Fc receptor expression to levels similar to those seen with eosinophils from infected animals. These same supernatants had no effect on the expression of granulocyte complement receptors. It is suggested that infection of rats with M. corti can lead to the production of an antigen-specific suppression capable of impairing the antibody-dependent activity of granulocytes in vitro.

Animals↗
PubMed1988

Proteinase phenotypes and fixation properties of rat mast cells in parasitic lesions caused by Mesocestoides corti: selective and site-specific recruitment of mast cell subsets.

The distribution, fixation properties, and protease phenotypes of mast cells populating lesions caused by the metacestode stage of the cestode Mesocestoides corti in the rat were characterized. Intraperitoneal infection with M. corti induced severe granulomatous types of reactions around the pancreas and further lesions in the liver. These sites were infiltrated with mast cells which contained either rat mast cell protease I or II derived respectively from connective tissue (CTMC) or mucosal mast cells (MMC). A proportion of cells in pancreatic granulomas had staining and fixation properties identical to those of intestinal mucosal mast cells; others were typical connective tissue mast cells. Subcutaneous inoculation of parasites was associated with nodular dermal reactions, and all of the infiltrating mast cells had the fixation and staining properties of CTMC and contained RMCPI uniquely. Increased numbers of RMCPII-containing mast cells were present in the intestines of rats infected intraperitoneally. Significant quantities of RMCPII were present in homogenates of pancreatic granulomas and in livers of rats harbouring intraperitoneal infections but none was detected in skin. These findings suggest that mast cells of different phenotypes are selectively recruited to some, but not all, lesions.

Animals↗
PubMed1985

Analysis of six serum components from rats infected with tetrathyridia of Mesocestoides corti.

The serum from rats infected intraperitoneally (i.p.) and subcutaneously (s.c.) with the tetrathyridia of Mesocestoides corti was analysed for alpha-amylase, alkaline phosphatase, gamma-glutamyltransferase, glucose, corticosterone and total proteins. A histochemical analysis for hepatic alkaline phosphatase was also carried out. A significant decrease in activity of serum alkaline phosphatase was detected in both the i.p. and s.c. infections, whereas a large increase in hepatic alkaline phosphatase was observed in i.p. infections. A significant increase in serum corticosterone was found in both the i.p. and s.c. infections. No changes were detected in the other four components. The relevance of these findings is discussed with respect to the host-parasite relationship.

Alkaline Phosphatase↗
PubMed1983

The pathology induced in laboratory rats by metacestodes of Taenia crassiceps and Mesocestoides corti (Cestoda).

Sprague-Dawley rats were infected by intraperitoneal injection with either the cysticerci of Taenia crassiceps or the tetrathyridia of Mesocestoides corti. Both species of metacestodes reproduce asexually in the peritoneal cavity. The effect of T. crassiceps upon the rats was to cause chronic inflammation of the peritoneum, fibrous adhesions between the visceral organs and hyperplasia of the gut mesenteries which became extended into a large sac-like structure. Dead parasites surrounded by white calcareous material were found free in the peritoneum and attached to the inner body wall and viscera. The histopathology of the hyperplastic mesenteries and fibrous membrane is described. The tetrathyridia of M. corti were found free in the peritoneal cavity as well as in the liver (mainly the left liver-lobe), gut mesenteries and in an outgrowth of the connective tissue associated with the pancreas. The connective tissue outgrowth comprised 2 layers; an inner reticular layer and a thickened marginal layer. Metacestodes were found in collagen-fibrin capsules within the connective tissue. A layer of mucopolysaccharide material was interposed between the parasite and the capsule wall. A possible method by which the parasites gain entry into the connective tissue is described. The connective tissues of rats harbouring either M. corti or T. crassiceps had increased numbers of mast cells compared to connective tissues from control rats. Younger mast cells containing biogenic amines predominated in infected tissues whereas older heparin-containing cells dominated control tissues.

Animals↗
PubMed1982

The nature of antigens common to both the metacestodes of Taenia crassiceps and its laboratory host.

Metacestodes of Taenia crassiceps were cultured in laboratory rats and mice, washed in glycine/hydrochloric acid (Gly/Hcl) buffer pH 2.4 and phosphate buffered saline (PBS) pH 7.2 and a soluble extract of the metacestodes (SEM) was prepared from larvae washed in both buffers. The SEM and the original washings were examined for host IgG and a common host antigen (CHA). CHA was present in both the SEM and washings but IgG only in the washings and, in metacestodes from mice only in the Gly/HCl washings). Metacestodes washed in Gly/HCl were not viable. Metacestodes were also maintained in vitro in a peptide nutrient agar and 0.9% saline at 37 degrees C and a SEM was prepared from these; metacestodes from mice had neither host IgG nor CHA but those from rats had CHA but not IgG. SEM prepared from 'normal' metacestodes showed that the CHA consisted of at least two entities, only one having a common identity with the IgG. These results suggest that molecules of both host IgG and a common host antigen are present on the tegument of these parasites.

Animals↗
PubMed1981

The growth and antigenicity of the metacestodes of Taenia crassiceps in several different strains of rats.

The metacestodes of Taenia crassiceps removed from a stock infection of Sprague Dawley rats were injected into seven inbred and one outbred strain of rats. The results showed that over-all female rats are more susceptible to the infection than male rats. Only one strain of rat, the Lewis male rats, was found to be resistant to the infection. There was no significant differences in the volume of metacestodes recovered from the male and female rats. The sizes of the metacestodes, after two passages through the rats, were compared to those of the original mouse strain and it was found that metacestodes from two strains of rats were significantly smaller. The antigenic expression of the metacestodes from the different strains of rats was compared and some variation in the antigenicity was observed.

Animals↗
PubMed1977

Aspects of the humoral response to laboratory white mice infected with the metacestodes of Taenia crassiceps.

Two strains of laboratory white mice, CFLP and LACA, were infected with the metacestodes of Taenia crassiceps. The serum from each infected mouse was tested for antibodies on double-diffusion gel plates and the number of antigen-antibody precipitin lines formed related (a) to the duration of the infection and (b) to the volume of metacestodes. There was a significant increase in the number of antigen-antibody precipitins with regard to the time infected but not to the volume of metacestodes. The pattern of development of the antigen-antibody precipitation system was also examined.

Animals↗
PubMed1977

Common host antigens in laboratory rats infected with the metacestodes of Taenia crassiceps.

Laboratory rats were infected by intra-peritoneal injection with the metacestodes of Taenia crassiceps. A soluble extract was prepared from the metacestodes removed from the peritoneal cavity of the rats. Double-diffusion, immuno-electrophoresis and fluorescent labelled antibody staining techniques were used. The extract tested against rabbit anti-normal rat serum was found to contain an antigen common to both the host and the parasite.

Animals↗
PubMed1975

The growth of the metacestodes of Taenia crassiceps in white mice.

The effect of the sex of the intermediate host on the growth and development of the metacestodes of Taenia crassiceps has been investigated. Three different strains of mice were used, the C R S, L A C A and C F L P strains and two strains of metacestode, the Toi and the E R S strains. The results show that matacestodes of T. crassiceps grow and multiply more rapidly in female than in male mice, although both sexes are equally susceptible to the infection. The origin of the parasite, i.e., from a rat or mouse host, affects the parasite growth.

Animals↗