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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

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

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

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

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

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

Detection of antibodies to Neisseria gonorrhoeae by counterimmunoelectrophoresis.

Antigen was partially purified from Neisseria gonorrhoeae B370 saline wash and used to assay human sera for the presence of antibodies to N. gonorrhoeae. The antigen activity as monitored by counterimmunoelectrophoresis (CIE) is resistant to trypsin and papain but sensitive to heat and periodate oxidation. Of the sera from patients with bacteriologically confirmed cases of gonorrhea, 80% were positive by CIE using this antigen preparation. Of the sera in the negative control group 11% were reactive.

Antibodies, Bacterial

Babesiosis: malaria mimic.

Human infection with blood parasites of the genus Babesia can result in a hemolytic disease very similar to malaria. Laboratory diagnosis of babesiosis is dependent upon the detection and identification of the parasite in blood films. The distinguishing criteria are: lack of pigment in infected red blood cells; no circulating schizonts or gametocytes; "atypical" malarialike organisms; tetrad groups, rods, or exclamation-mark forms; and persisting parasitemia after treatment for malaria.

Animals

Gonorrhea card test: an agglutination test for uncomplicated gonorrhea.

An antigen extracted and purified from Neisseria gonorrhoeae B370, type 4, was employed to sensitize charcoal particles for use in an agglutination assay of human sera for antibodies that indicate active gonorrheal infection. The screening card test is more sensitive than the fluorescent gonorrheal test-heated (FGT-H), especially in men. A simple one-step absorption improved the specificity without reducing the sensitivity of the test.

Agglutination Tests

Purification of Neisseria gonorrhoeae surface L-antigen.

A purified preparation of the L-antigen of Neisseria gonorrhoeae with a 40-fold increase of antigenic activity over the crude extract was prepared. The antigen was extracted from the cell envelope by mild treatment with sodium dodecyl sulfate and purified by Sepharose 4B, diethylaminoethyl-cellulose, and diethyl-(2-hydroxypropyl)aminoethyl (QAE)-Sephadex column chromatography. The purified antigen was heat labile and trypsin sensitive. The smallest antigenically active subunit appeared to have a molecular weight of 38,500, as shown by polyacrylamide gel electrophoresis of the product incubated with sodium dodecyl sulfate.

Antigens, Bacterial

The role of plasma cells in scleroma. Electron-microscopic study.

Three cases of rhinoscleroma in the granulomatous stage were examined under the electrom microscope. The rough endoplasmic reticulum of plasma cells in scleroma displayed cisternal dilatations forming Russell bodies and cytoplasmic vacuolations containing viable and degenerated bacilli forming Mikulicz cells. Thus, they play a double role, producing antibodies and providing protection for the intracellular bacilli. New ultrastructural findings of Klebsiella rhinoscleromatic bacilli were described.

Humans

Bacteriocin production by Neisseria gonorrhoeae.

Seventeen apparently unrelated isolates of Neisseria gonorrhoeae out of 2,123 tested produced a diffusible growth-inhibitory substance against other gonococci. The inhibitor was destroyed by trypsin, not blocked by bovine serum albumin, and not soluble in chloroform-methanol; each isolate was resistant to the inhibitor it produced. Thus, the substance differs from previously described gonococcal inhibitors, and since it fits the description of a bacteriocin we designated it gonocin. The use of gonocin for typing was complicated by the observation that susceptibility to gonocin appears to depend on the gonococcal colony type.

Bacteriocins

Fluorescent antibody test for the serological diagnosis of gonorrhea.

An indirect fluorescent antibody technique has been developed for the serological diagnosis of gonorrhea. The selected strain(s) of Neisseria gonorrhoeae possesses a heat-labile surface antigen (L-antigen). Sera are diluted 1:10, and an aliquot is hear inactivated at 59 C for 30 min. The treated and untreated aliquots are then examined for human immunoglobulin G anti-L-antigen. In a prelimiary study of 495 sera, 95% of those from women with a bacteriologically confirmed diagnosis of gorrhea and 87% of those from male patients were reactive in this test, whereas only 1.4% fo the sera from presumably normal individuals were reactive.

Antibodies, Bacterial

Evaluation of the fluorescent gonococcal test-heated.

In a 1-year evaluation of the indirect fluorescent antibody test for gonorrhea, 16,127 specimens from low-and high-risk groups were examined, and the results were compared with culture, history of exposure to a known patient, and clinical signs and symptoms. The results confirmed the usefulness of the indirect fluorescent antibody test for gonorrhea as a screening procedure, especially for women in the low-risk group. The test is more economic and probably more sensitive than culture for mass screening of asymptomatic women.

Adult