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Biomedical subjects

L Mandel

Publications and source records attributed to L Mandel.

At least 19 recordsLinked to original sources
PubMed1992

HIV parotid gland lymphoepithelial cysts. Review and case reports.

Lymphoepithelial cysts of the parotid gland are frequently associated with cervical lymphadenopathy. These unique cysts have recently been recognized as another manifestation of HIV disease. Proliferation of lymphocytes and salivary gland tissue contained within intra-parotid lymph nodes is observed. The lymphoepithelial cyst is the end product. Ultrasound imaging serves as an excellent technique to demonstrate the existence of these cysts.

Adult↗
PubMed1992

Skin response to tuberculin in pig foetuses and germ-free piglets.

Cellular response to intradermally administered PPD (2 TU) was demonstrated in pig foetuses of various ages and in germ-free piglets. CD2+, CD4+, CD8-, 86D-, SLA-D- T lymphocytes were the predominant cells in the skin tuberculin reaction in both foetuses and germ-free animals. Reactive T cells were observed as early as in mid-gestation, whereas SLA-D+ (porcine MHC class II) cells appeared only in older foetuses. Polymorphonuclear leukocytes were never observed in the PPD reaction.

Animals↗
PubMed1992

A cluster of vancomycin-resistant Enterococcus faecium in an intensive care unit.

OBJECTIVE: To describe the epidemiology of a cluster of vancomycin-resistant Enterococcus faecium (VAREC) in a cardiothoracic surgery intensive care unit. DESIGN: A case series of patients identified through review of surveillance data on nosocomial infections, review of microbiologic records, and culture survey of patients in the unit. RESULTS: Six patients in the cardiothoracic surgery intensive care unit had VAREC with identical antimicrobic susceptibility patterns over a 6-month period. Four patients were identified with VAREC through prospective surveillance and 2 through retrospective review. Prior vancomycin use was seen more commonly in patients with VAREC (6/6, 100%) than in those without VAREC (3/12, 25%) (Fisher's exact test, p = .01). Six of the 7 patients with prior infection developed VAREC (85.7%). A prior nosocomial infection and prior exposure to vancomycin were found to be important variables in a logistic regression analysis. VAREC also was isolated from the environment. A combination of cohorting of patients and staff, and modifications of standard contact isolation practices eliminated the presence of VAREC from the cardiothoracic surgery intensive care unit. CONCLUSIONS: The results suggest that prior administration of vancomycin, especially in the patient who develops nosocomial infection, can influence the acquisition of vancomycin-resistant enterococci and that VAREC may be transmitted from patient to patient. Using a modification of the standard infection control practice of isolation, we were able to control the spread of this resistant strain of E faecium.

Cross Infection↗
PubMed1992

Persistent infection with Chlamydia pneumoniae following acute respiratory illness.

Chlamydia pneumoniae is emerging as a significant cause of respiratory disease, including pneumonia and bronchitis, in humans. In this recently completed study of infection due to C. pneumoniae in patients presenting with pneumonia to SUNY Health Science Center at Brooklyn, we identified two individuals for whom cultures were positive on multiple occasions over a 1-year period. To determine the frequency of persistent respiratory infection with C. pneumoniae, follow-up specimens were obtained from nine individuals with culture-documented C. pneumoniae infection. Five of these individuals had persistent infection: four had a flulike illness characterized by pharyngitis, and one had bronchitis with prominent bronchospasm. All five individuals appeared to have acute C. pneumoniae infection as determined by results of serologic tests (titers of IgM antibody for all individuals were greater than or equal to 1:16). For three patients, cultures remained positive for 11 months despite therapy with 10- to 21-day courses of tetracycline or doxycycline. These observations suggest that persistent infection with C. pneumoniae may follow acute infection and may persist for many months. Infection with C. pneumoniae may be very difficult to eradicate with use of currently available antibiotics even if there is a clinical response to therapy.

Acute Disease↗
PubMed1992

Autoimmunity: from physiology to pathology. Natural antibodies, mucosal immunity and development of B cell repertoire.

Presence of spontaneously produced immunoglobulins bearing a broad spectrum of "natural" antibody specificities (including autoantibodies) in sera and other body fluids results mainly from inapparent immunization and polyclonal B cell activation by microflora and food antigens occurring mostly on mucosal surfaces. Early postnatal ontogeny in external environment is characterized by rapid growth and functional maturation of secondary lymphatic tissues as a consequence of this "natural" mucosal immunization. Under normal circumstances a state of "oral" tolerance to intestinal antigens is actively established after this period. Studies performed in germ-free, antigen-free and maternal antibody-deprived animals showed that low amounts of natural antibodies (mainly of IgM isotype) are formed without any known cause of stimulation. These "nonstimulated" antibodies, similarly as hybridomas originating from nonimmunized newborns, correspond to the preimmune repertoire of antibodies characterized by poly-specificity, high connectivity and reactivity against self antigens. Together with other innate humoral and cellular factors, they probably represent the first line of anti-infectious resistance. Moreover, due to their connectivity they are supposed to play an important role in B cell repertoire shaping (forming an idiotypic network), through interaction with a broad spectrum of immunological components they act as regulatory molecules, and through their participation in catabolic events they can promote morphogenetic changes during fetal development. Beneficial therapeutic effects of nonspecific gammaglobulin (IVIG) application observed recently in patients with autoimmune diseases suggest that they can influence autoimmune reactivity by a not yet analyzed mechanism. Other functions of natural autoantibodies can be suggested and expected to be found in the near future.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoimmunity↗
PubMed1991

Pneumoparotid: a case report.

Pneumoparotid is an unusual condition resulting from air being forced into the parotid ductal system. When it develops, it is a result of increased intraoral air pressure. Diagnosis is based on the etiologic factor, palpatory evidence of tissue emphysema, the escape of frothy saliva from the involved duct, and the sialographic finding of retained ductal air and ductal infection.

Emphysema↗
PubMed1991

Polycystic parotid disease: a case report.

A case report of a 14-year-old girl, presumed to have PPD, is presented. Those manifestations of this patient's disease that can be added to the classic picture of PPD include a decreased salivary flow rate and a sialochemistry that reflects a mild chronic parotitis. In addition, cysts and sialoliths were demonstrated grossly rather than microscopically.

Adolescent↗
PubMed1991

Parotid enlargement in children seropositive for human immunodeficiency virus: imaging findings.

We investigated the clinical, immunologic, and imaging features of parotid enlargement in 10 children seropositive for human immunodeficiency virus (HIV) who were infected prenatally. In seven patients, sonography revealed many small hypoechoic areas suggestive of lymphoid infiltration. In three older children, large anechoic areas suggesting lymphoepithelial cysts were present. The lesions probably represent generalized lymphoid infiltration akin to pulmonary lymphoid hyperplasia, although only two of our patients had radiologic evidence of pulmonary lymphoid hyperplasia. Four of five of the children with parotid enlargement who had immunologic studies were phenotypically HLA-DR5, an immunophenotype associated with improved immune response, occurring in less than one in four in the normal population. This suggests that painless parotid enlargement may be a good prognostic sign in HIV-seropositive children. Parotid enlargement was found in 10 HIV-positive children from 6 months to 11 years old. All except one were infected prenatally.

Antibodies, Viral↗
PubMed1991

[The gastrointestinal post-irradiation syndrome].

In the recent years, more attention is paid by radiobiologists to both prevention and therapy of a relatively less studied gastrointestinal postirradiation syndrome (GPS). Moreover, the increase in interest in GPS is motivated with the requirement as to obtain the decrease in action of ionizing radiation on the intestinal mucosa at making radiotherapy of abdominal or pelvic region. The GPS occurs consequently to the affected abdominal region or all the organism with ionizing radiation. Its approximal doses from 10 to 100 Gy (gamma) are critical for the survival of intestinal mucosa, especially that of jejunum and ileum. Under the threshold of a single and total dose from 6 to 10 Gy, the intestinal mucosa may usually regenerate, and the survival depends mainly on the preservation or restoration of hemopoietic activity of blood forming tissues. The main pathogenetic GPS factor resides in the afflication of stem cells of mucosal crypts. The intestinal epithelium stops to be fluently replaced after the irradiation. The motion arrests of epithelial cells from crypts to the apex of villi. The elderly cells undergoes degradation, and after several days the denudation of mucosa occurs with possible distortion of deeper layers of intestinal wall. The intestinal microflora is involved in the pathogenesis both directly and indirectly. Amongst the former events is ranged the invasion of distorted mucosa in compromised both local and systemic immunity. Indirectly, the intestinal microflora is GPS associated by stimulating mitotic activity in crypts, therefore more cells are in the radiosensitive phase. In germ-free animals there is a significant decrease in mitotic activity of crypts, and the migration time of epithelial cells from crypts to the apex villi is twice more prolongated, what induces possible restoration of active center after the irradiation. The GPS also results in disorder of metabolic processes which are conditioned with intestinal mucosa. Its typical manifestation resides in the wash-out of mucus, decreased resorption of nutrients and loss of water and minerals into the intestinal lumen. The GPS-related are another disorders of the organism, those of liver and kidney apparently induced due to the intoxication with catabolic products. The microflora has been stated to be involved in GPS by the experiments on germ-free animals. In the absence of microflora, the survival is greater in duration. After a total pigs irradiation with 10-30 Gy, more than two times survival prolongation occurs. The abdominal irradiation with 12 Gy results to the death of only conventional pigs, whereas those germ-free show a survival.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Ontogeny of MHC class II antigens in pigs.

Cells constitutively expressing MHC class II antigens have been studied in the course of prenatal development in the Minnesota miniature pig. Frozen sections, cell suspensions and peripheral blood mononuclear cells were examined by using the HL-40 monoclonal antibody cross-reactive with a light chain determinant of the SLA-D molecule (MHC class II porcine antigen). It could be demonstrated that the yolk sac contained cells expressing SLA-D antigens as early as the 24th day, the liver and the spleen on the 39th day of gestation. Splenic cells bearing SLA-D molecules formed periarteriolar structures. Except the spleen, peripheral blood, lymph nodes, bone marrow and intestinal wall were the main sites of SLA-D expression in the perinatal period of the pig.

Animals↗
PubMed1990

Postirradiation changes in small intestine mucosa of piglets selectively decontaminated by peroral antibiotics.

There was performed light microscopic and morphometric comparison of changes in the intestinal mucosa structure after the irradiation of the lower part of body by radiation 60Co in a dose of 12 Gy, observed the third day after irradiation in piglets kept under conventional conditions and the fifth, the fifteenth and the twentieth days after irradiation in piglets kept under the conditions of selective decontamination by peroral antibiotics. The non-irradiated animals kept conventionally as well as under the conditions of decontamination served as controls. The estimation was performed on transverse slices of the cranial part of jejunum and of the caudal part of ileum. The slices were stained by the method hematoxylin-eosin. The drawings prepared with the help of the projective microscope Pictoval were used for measuring on the apparatus for the quantitative analysis of image MOP AM 03. A markedly lower damage of the intestinal mucosa was evidenced in piglets selectively decontaminated by peroral antibiotics. In the studied time intervals after irradiation in a dose of 12 Gy, the epithelial cover of mucosa, the crypt epithelium and the general outline of mucosa are much better maintained. The favourable effect of the selective decontamination on the maintenance and regeneration of the mucosa of jejunum and ileum is confirmed by a range of morphometric parameters.

Administration, Oral↗
PubMed1989

Stimulating effect of Streptococcus faecalis on phagocytosis in gnotobiotic piglets.

The concentration of active phagocytes in peripheral blood remained in germfree pigs up to the age of one year approximately at the same level as found at the age of 7 d and did not exceed 0.3 X 10(9)/L of blood, whereas a steady increase was established in conventional pigs. Monoassociation of gnotobiotic piglets with Streptococcus faecalis increased during 24 h the concentration of circulating granulocytes and the concentration of active phagocytes. An even more pronounced effect was obtained when formolized S. faecalis cells were applied intraperitoneally to germfree piglets. This treatment elevated the phagocytosis index also in conventional piglets, as well as in germfree piglets previously given cyclophosphamide. Escherichia coli O 83 or a mixture of anaerobic bacteria did not cause any serious changes in the activity of phagocytosis in gnotobiotic piglets. S. faecalis seems to be a natural factor stimulating both the release of granulocytes from their depots as well as their phagocytic activity.

Animals↗