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Biomedical subjects

H A Gaafar

Publications and source records attributed to H A Gaafar.

At least 19 recordsLinked to original sources
PubMed2000

Experimental intravenous inoculation of Klebsiella rhinoscleromatis bacilli in albino rats: a histopathological and bacteriological study.

Scleroma, chronic specific granuloma of the nose and upper respiratory tract, is endemic in Egypt and many other countries. The exact pathogenesis of the disease as regards the aetiological role of Klebsiella rhinoscleromatis is contradictory. This work investigated the effect of experimental intravenous injection of K. rhinoscleromatis in albino rats to demonstrate that the micro-organism can fulfil Koch's postulates. Micro-organisms were isolated from biopsy specimens taken from nasal lesions of 10 patients in the granulomatous stage of scleroma. Specimens were subjected to bacteriological and histopathological examinations to confirm the diagnosis. A 100 microl volume of freshly prepared bacterial inoculum containing 10(8) cfu/ml was injected weekly in the tail vein of each of 30 albino rats for 5 consecutive weeks. Biopsy specimens were taken from sacrificed animals and subjected to bacteriological and histopathological examinations. Positive histopathological diagnosis of scleroma was reported in the nose of 66.7% of rats, the larynx of 46.7%, the lungs of 26.7% and liver of 20% of rats. Bacteriological techniques were successful in revealing K. rhinoscleromatis from the nose of 36.7% of rats, the larynx of 30% and the lungs of 20% of rats. Various techniques were carried out to demonstrate the micro-organisms in tissue sections. Two histochemical stains for bacteria were employed: silver and Periodic Acid Schiff (PAS) stains. Immunoperoxidase technique using Klebsiella capsular type 3 antiserum was applied. It gave positive results in 66.7% of the 6 stained liver sections in spite of negative bacteriological cultures. The histiocytic nature of the Mikulicz cells was confirmed using alpha-1 antitrypsin, an immunohistochemical marker of histiocytes, and by studying the ultrastructural features of Mikulicz cells using the transmission electron microscope.

Adult↗
PubMed1998

The vomeronasal (Jacobson's) organ in adult humans: frequency of occurrence and enzymatic study.

The vomeronasal system in adult humans has commonly been regarded as absent or vestigial, but recently it was found to be more common than previously reported. In this study, a search for the frequency of occurrence of the vomeronasal organ (VNO) was performed by examining the nasal septae of 200 adult patients. The frequency of occurrence was found to vary according to the method of examination. By anterior rhinoscopy, large pits and even deep grooves lined by glistening mucosa were visible in 16% of the people examined. Using nasal endoscopes this ratio increased to 76%. After receiving informed, written consent, from 13 patients undergoing endonasal surgery under general anaesthesia, one VNO was dissected out. Specimens were examined histologically and histochemically for succinic dehydrogenase and alkaline phosphatase enzymes. One specimen was processed for transmission electron microscopy. Two morphologically distinct cell types were differentiated. One cell type was previously suggested to have some of the features associated with nerve cells and could have a sensory function. A possible function for the VNO is postulated.

Adult↗
PubMed1991

Scleroma of the upper respiratory passages: a CT study.

Scleroma is a chronic specific granulomatous disease endemic in Egypt. The nasal cavities were all affected in the 37 patients examined. The paranasal sinuses and nasopharynx were involved in 17 patients, while the larynx and upper trachea were affected in five patients, four of whom were females. Twenty-three patients were in the granulomatous stage; the rest of the patients were in the atrophic and fibrotic stages. The main nasal and nasopharyngeal CT findings were soft tissue masses of variable sizes. The lesions were characteristically homogenous, non-enhancing and had distinct edge definition; adjacent fascial planes were not invaded. The subglottic area was involved in laryngeal and tracheal scleroma. The lesions were mainly in the form of concentric irregular narrowing of the airway. In the trachea, crypt-like irregularities were diagnostic of scleroma. Intra-orbital, intra-cranial and infratemporal parapharyngeal scleromatous masses were detected in one patient.

Adolescent↗
PubMed1983

Endoscopy of lower respiratory tract scleroma.

Eleven cases of scleroma with lower respiratory tract affection were examined by the flexible and rigid bronchoscopes. The patterns of laryngeal, tracheal and bronchial scleroma as seen through the flexible scope are presented. In the larynx, diffuse and localized forms are found. The trachea was affected by granular or atrophic lesions. Stenosis of the main bronchi was seen in two patients. The present-day treatment of lower respiratory tract scleroma is discussed.

Adolescent↗
PubMed1983

Toxofactor associated with Toxoplasma gondii infection is toxic and teratogenic to mice.

A toxin associated with Toxoplasma gondii infection was obtained from the trophozoites and culture medium used to propagate the parasite in cell cultures. The toxin, named Toxofactor (TF), administered parenterally or nonparenterally in adult mice, produces transient symptoms of lethargy, ruffled fur, and body weight loss. Organ changes which accompanied the outward symptoms included hepatosplenomegaly and involuted thymus. TF activity was detected in extracts of the blood, peritoneal fluid, liver, and spleen of infected mice. Severe damage to embryonal and fetal development was induced when TF was administered during pregnancy. Resorption, abortion, and congenital abnormalities were produced, dependent upon the stage of development at the time of exposure. Adult mice which had reacted to and recovered from an initial intraperitoneal injection to TF were protected against a secondary challenge from TF. Fetal development was also protected from damage when TF was used to challenge adults previously exposed to TF. Mouse and rabbit anti-TF sera neutralized TF activity in the adult. In no instance did control mice show any deleterious effect when exposed to soluble cell lysate from the uninfected cell line (BHK-21) used to propagate the organism plus the used medium from these same uninfected cells. TF activity was not attributed to bacterial, myocoplasmal, or viral contamination. TF toxic activity is labile to elevated temperature and high or low pH, which also destroy its protective properties. TF activity was sensitive to trypsin and was obtained in the elution fraction (alpha-methyl-D-mannoside) from affinity chromatography (concanavalin A-Sepharose 4B). Ultrafiltration indicated the molecular weight to be between 50,000 and 100,000. TF, apparently a glycoprotein, was quantitated for activity by a weight loss assay. A unit of activity was defined as the minimum quantity of TF (highest dilution) which produced at least a 10% average body weight loss in adult Nya:NYLAR female mice between days 7 and 12 post-intraperitoneal injection.

Abnormalities, Drug-Induced↗
PubMed1983

Absorption of Rickettsia rickettsii antibodies by Rickettsia rickettsii antigens in four diagnostic tests.

Immunoabsorption profiles were determined for Rickettsia rickettsii antigens used in four confirmatory tests for detection of antibodies to Rocky Mountain spotted fever. A human serum reactive in the four tests was absorbed with each test antigen and then reexamined by all four tests. The results indicated that the whole organism and complement-fixation antigen absorbed the whole array of antibodies to R. rickettsii, whereas erythrocyte-sensitizing substance coated on latex or erythrocytes did not. With erythrocyte-sensitizing substance coated on latex there was a decrease in titer when tested by the latex, indirect hemagglutination, and complement fixation tests but none when tested by the microimmunofluorescence test. With erythrocyte-sensitizing substance coated on sheep erythrocytes there was a decrease in titer when tested by indirect hemagglutination or complement fixation but none when tested by latex or microimmunofluorescence. These findings confirm that erythrocyte-sensitizing substance contains more than a single antigenic substance and plays a major role in the complement fixation test and a minor role in the microimmunofluorescence test.

Antibodies, Bacterial↗
PubMed1982

The effect of cigarette smoke on the tracheal mucosa of the rabbit. An electron microscopic study.

The effect of whole cigarette smoke on the tracheal mucosa of the rabbit has been studied by the electron microscope. The epithelium shows oedema and disturbed stratification. The cilia are sparse and some show clubbing. The basal cells are active. Large amorphorous bodies and numerous vacuoles are found in the tunica propria. Some damage in the smooth muscles is found. The irritative effect of cigarette smoke on the epithelium is demonstrated. Factors which may explain the rare incidence of malignancy in the trachea are discussed.

Animals↗
PubMed1981

The effect of cigarette smoke on the vocal cord mucosa of the rabbit: An electron microscopic study.

The effect of whole cigarette smoke on the vocal cord mucosa of the rabbit has been studied with the electron microscope. The epithelium shows variable degrees of hyperplasia, with enlargement of the basal cells. Variable degrees of damage are found in the nerves and muscles in the tunica propria. The relationship between these changes, some endogenous factors in the larynx and the development of cancer are discussed. A possible toxic effect of cigarette smoke on the nerves and muscles of the larynx is mentioned.

Animals↗
PubMed1981

Evaluation of preservation methods and solid media suitable for recovery of Ureaplasma urealyticum from transported urine specimens.

Urine specimens to be tested for Ureaplasma urealyticum (T-strain mycoplasma) must often be transported to a central laboratory for identification. To examine survival of these organisms over 2 days of transport, fresh urine samples were tested for the presence of ureaplasmas and then divided into four groups: (i) fresh, (ii) frozen, (iii) preserved with 1% (wt/vol) boric acid at room temperature, and (iv) preserved with 10% dimethyl sulfoxide and frozen. The samples were cultured on both A7 and New York City solid media, and the estimates of survival were compared to that of fresh urine. Less than 10% survival of Ureaplasma was observed in 11 of 14 specimens stored frozen for 2 days without preservation; six specimens lost all organisms. Specimens containing either dimethyl sulfoxide or boric acid showed higher survival rates, although neither method consistently approached the full recovery of the T-strains found with the fresh urine. Ureaplasmas from fresh specimens grew well on both New York City and A7 media; however, the New York City medium proved superior for those preserved with boric acid and for urine samples containing few ureaplasmas. These results indicate that preservation of samples does increase the yield of U. urealyticum from urine samples delayed in transit.

Bacteriological Techniques↗
PubMed1979

Application of fluoroimmunoassay to cerebrospinal fluid immunoglobulin G and albumin.

Special solid-phase fluoroimmunoasssay protocols were used to measure the amount of immunoglobulin G (IgG) and albumin in 1,511 samples of cerebrospinal fluid. The fluoroimmunoassay is an inhibition test conducted on the surface of a plastic probe, whose fluorescence is inversely related to the concentration of spinal fluid IgG or albumin. A microcomputer interfaced with the fluorometer calculates the sample IgG or albumin from a calibration curve based on standard cerebrospinal fluid values. The test and interpretation take less than 90 min. Correlation coefficients for over 100 cerebrospinal fluid samples tested by both fluoroimmunoassay and radial immunodiffusion were: IgG, 0.90 (slope, 1.04); albumin, 0.95 (slope, 0.99). The within-run precision (coefficient of variation) was: IgG, 4.4%; albumin, 6.3%. Run-to-run precision on a midrange sample was: IgG, 7.7%, albumin, 11.7%. These findings establish the simplicity, speed, and precision of the modified fluoroimmunoassay system for specific cerebrospinal fluid proteins.

Adolescent↗
PubMed1979

Serologic diagnosis of gonococcal infection.

Infection with N. gonorrhoeae stimulates the production of antibodies to many common, species-specific, and type-specific antigens. The L-antigen is an envelop antigen and antibodies to it could be demonstrated by various methods in more than 90% of the patients after the first 10 days of infection. Serologic tests are not yet available in the United States. If and when they become available, they may be recommended for: (1) Screening asymptomatic men and women, (2) Use as an adjunct diagnostic tool in cases of prostatitis, arthritis, disseminated gonococcal infection, and pelvic inflammatory disease, (3) Use (alone or in conjunction with culture) when specimens must be mailed to a central laboratory, when mailing conditions do not allow for incubation within 24-48 hr, or when proper media and qualified bacteriologists are not available.

Antigens, Bacterial↗
PubMed1979

Yersinia enterocolitica in Oneida County, New York.

In a 7-month study during and after an outbreak of Yersiniosis in Oneida, N.Y., a total of 963 specimens were examined for Yersinia enterocolitica. Of the 103 Y. enterocolitica isolates recovered, 91 were from Oneida County. Sixty-two (60.2%) were from humans including 52 from Oneida County. The isolates from the outbreak were mainly serotype 0:8, which on biotypnig proved to be Niléhn type 2, Wauters type 1, Knapp and Thal type 2. The rest of the isolates were distributed among various biotypes and included organisms which belonged to eight different serotypes. The results suggest that Y. enterocolitica may be ubiquitous in New York State, as it was isolated from 10 to 25% of 275 water, milk, and animal specimens examined and from about 2.3% of 300 sequential stool specimens submitted for Salmonella and Shigella screening.

Animals↗
PubMed1978

Evaluation of reagin card tests for syphilis.

The macroscopic rapid plasma reagin (RPR) and reagin screen (RST) card tests for syphilis were compared. Test specimens were also examined with the Venereal Disease Research Laboratory (VDRL) microscopic slide test; those reactive in the card or slide tests were examined with the fluorescent treponemal antibody-absorption (FTA-ABS) procedure. Agreement between the card tests with 2,300 specimens was 99%; among all three reagin tests it was 96.3%. With 348 specimens reactive in one or more of the tests, there was 75.6% agreement among all three tests. The FTA-ABS was reactive with 71% of the RPR- or RST- and 65% of the VDRL-reactive specimens. The comparison showed that the card tests give results in close agreement with those of VDRL while offering a number of practical advantages over it.

Adult↗