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Biomedical subjects

O A Husain

Publications and source records attributed to O A Husain.

At least 19 recordsLinked to original sources

Monoclonal immunofluorescence compared with silver stain for investigating Pneumocystis carinii pneumonia.

Two hundred and eighty two specimens from 220 patients positive for HIV with respiratory tract symptoms, or febrile illness, or both, were examined for the presence of Pneumocystis carinii. Specimens were either induced sputum samples or bronchoalveolar lavage fluids. To establish the optimal method for laboratory diagnosis a comparison was made of detection of the organism by use of monoclonal antibody and immunofluorescence with conventional silver staining methods. Three commercially available reagents for immunofluorescence were also compared. Immunofluorescence was significantly more sensitive than the silver stain and the best results for immunofluorescence were obtained using. Northumbria Biologicals Ltd reagents.

Bronchoalveolar Lavage Fluid

Sputum induction for diagnosis of Pneumocystis carinii pneumonia.

51 patients infected with the human immunodeficiency virus (HIV) and with suspected Pneumocystis carinii pneumonia underwent sputum induction. Sputum specimens from 18 patients were positive for P carinii and patients were treated appropriately 25 of the 33 patients with negative specimens underwent bronchoscopy and bronchoalveolar lavage within 4 days of sputum induction, only 1 of whom had evidence of Pneumocystis infection. For diagnosis of Pneumocystis carinii pneumonia, sputum induction according to a strict protocol had a sensitivity of 94.7% and a negative predictive value of 96%, compared with bronchoalveolar lavage.

Acquired Immunodeficiency Syndrome

Oesophageal symptoms, their causes, treatment, and prognosis in patients with the acquired immunodeficiency syndrome.

In a prospective study of 154 AIDS patients, 48 (31%) complained of pain on swallowing both liquids and solids and 32 (21%) of these also had dysphagia. While candidiasis was the most common cause of symptoms (26 patients), discrete ulceration of the oesophagus occurred in 12 instances in 10 patients (four cytomegalovirus, four herpes simplex virus, three aphthous ulcer, one peptic ulcer). One patient had a diffuse oesophagitis caused by Mycobacterium avium intracellulare. No cause was found for the oesophageal symptoms in four patients. Kaposi's sarcoma (KS) was found in seven patients associated with other pathology in four. All 26 patients with oesophageal candidiasis only, also had oral involvement. All the patients with herpes simplex virus (four) and aphthous ulcers (three) had obvious perioral involvement. Three of the four patients with cytomegalovirus ulceration had evidence of disease elsewhere (colon or retina). All patients with Kaposi's sarcoma lesions had skin and buccal cavity involvement. The cause of oesophageal disease was usually obvious at endoscopy. The appearance of candidiasis was typical and the various ulcerating lesions also had different macroscopic configurations. Cytomegalovirus infection produced deep linear ulcers in the distal oesophagus, herpes simplex oesophagitis is similar in appearance to the typical perioral lesions of fluid filled vesicles. Diagnostic radiology was not helpful in most patients. In nine of 17 patients with candidiasis, the barium swallow examination performed within 24 hours of presentation was normal. In only three of seven patients with oesophageal ulceration (three cytomegalovirus, two herpes simplex virus, one aphthous, one peptic) was there evidence of an abnormality. Treatment produces symptomatic relief. All patients with candidiasis responded to ketoconazole, the four with herpes simplex virus to acyclovir and one of three with aphthous ulceration had a dramatic response to thalidomide. The three patients with cytomegalovirus infection who were treated with foscarnet had a prolonged remission of symptoms. The overall prognosis of patients with oesophageal symptoms is poor, with an average survival time from a definitive diagnosis of five months (range one to 13).

Acquired Immunodeficiency Syndrome

Cytology services.

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Cell Biology

Quantitative DNA analysis of low grade cervical intraepithelial neoplasia and human papillomavirus infection by static and flow cytometry.

Quantitative deoxyribonucleic acid (DNA) analysis of cervical biopsy specimens from 26 women with cytological, colposcopic, and histological evidence of mild cervical atypia consistent with cervical intraepithelial neoplasia grade I, reactive atypia, or human papillomavirus infection alone or in combination was performed in a comparative evaluation of Feulgen microspectrophotometry, the fast interval processor image analysis system, and flow cytometry. The fast interval processor image analysis system showed a distinct advantage over the other methods, being faster and allowing the operator to see the cells that were selected for measurement. The three methods of measurement together showed that the DNA content of at least 2% of the cells measured exceeded 5C (C being the haploid amount of DNA in a normal cell and 2C representing the diploid complement of a normal cell) in all cases of cervical intraepithelial neoplasia grade I and reactive atypia and in 87% of those reported as showing human papillomavirus infection alone. In contrast, the DNA content of cervical biopsy specimens from the transformation zone of 11 normal controls did not exceed 4C. This study shows the value of using a DNA threshold--that is, the "5C exceeding rate"--to distinguish between normal and neoplastic appearances of the cervix. These results support the view that cervical infection by human papillomavirus is a true precursor of neoplasia.

Aneuploidy

Quantitative deoxyribonucleic acid analysis of patients with mild cervical atypia: a potentially malignant lesion?

Quantitative deoxyribonucleic acid (DNA) analysis of cervical biopsy material from 32 women with cytologic, colposcopic, and histologic evidence of mild cervical atypia consistent with cervical intraepithelial neoplasia I, reactive atypia, or human papillomavirus infection was carried out using flow cytometry and Feulgen microspectrophotometry. Evidence of aneuploidy, ie, neoplastic transformation, was demonstrated in all cases of cervical intraepithelial neoplasia I and 68% of cases with human papillomavirus-induced atypia. These results support the growing impression that human papillomavirus-induced cervical atypia should be regarded as a true precursor of cervical neoplasia, and emphasize the necessity to refer patients with mild atypia for definitive diagnosis and management.

Carcinoma in Situ

Preparatory methods for DNA hydrolysis, cytochemistry, immunocytochemistry and ploidy analysis. Their application to automated and routine diagnostic cytopathology.

A review is presented of some methods used to prepare cytologic specimens for analytical and/or automated studies, with the steps of the procedures detailed in appendices. The preparation of the cell monolayers required for optimal automated cell image analysis and classification, e.g., by the Cytoscan 110, is discussed, as is the preparation of poly-L-lysine-coated slides used in the production of monolayered specimens. These monolayers, which can be prepared from a variety of specimens, are also useful for cytochemical and immunocytochemical studies and DNA ploidy analysis. For DNA analysis, a modified gallocyanin chrome alum staining procedure is described as a stoichiometric alternative to the time-consuming Feulgen reaction. The hydrolysis technique required by the latter method is also detailed. The freeze-fracturing technique for the enhancement of monoclonal antibody immunocytochemical staining of detectable antigens is described, along with an indirect immunoalkaline phosphatase staining method. The use of enzyme cytochemical reactions for glucose 6 phosphate dehydrogenase and lysosomal naphthylamidase is also presented.

DNA

Interpretation of negative results in fine needle aspiration of discrete pulmonary lesions.

A retrospective analysis was carried out on a consecutive series of 181 percutaneous fine needle aspiration biopsies of discrete pulmonary lesions, in which the outcome was established in 95%. In primary bronchial carcinoma the technique had a sensitivity of 86%. There was no relationship between the size, location, or radiological appearance of the lesion and the incidence of false negative results. The principal reason for failure to diagnose malignancy was inadequacy of the material provided for cytological examination. For metastatic neoplasms of non-bronchial origin the procedure had a sensitivity of 42% and a significantly greater false negative rate than for primary bronchial malignancy. For the entire series 72 (40%) of the procedures failed to produce a definite diagnosis, 29 (40%) of these cases subsequently proving to be malignant. A positive diagnosis was established in only 16% of patients with benign conditions. Review of published reports and consideration of the role of this and other biopsy techniques in the investigation of discrete pulmonary lesions lead to the conclusion that needle aspiration biopsy seems particularly appropriate in the investigation of inoperable patients with probable bronchial carcinoma in whom sputum cytology and bronchoscopy do not yield a diagnosis.

Biopsy, Needle

Cross contamination of cytological smears, with automated staining machines and bulk manual staining procedures. With a specific study of the problems of the Cytotek and the Shandon Elliott staining machines.

Further development of an individual staining machine is to be strongly encouraged but meanwhile, using bulk stainers, frequent changing of wash fluids and staining solutions, particularly leading up to and following the haematoxylin pot, is essential to reduce the risk of cross contamination. Certain smears, such as from semen or from serous fluids where malignancy is suspected or known, must be stained on separate racks. In some laboratories it is the rule not to stain semen or serous fluids in bulk staining machines at all and this may have to become the rule everywhere until we are provided with safe individual slide stainers.

Adenocarcinoma

Use of a mucolytic agent (Cytoclair) in the preparation of cell material for the detection of malignant cells in sputum.

A mucolytic agent, methyl cysteine HC1 (Cytoclair), has been used to obtain a centrifuged cell deposit for the detection of malignant cells in sputum. In 178 sputum samples from 52 patients with primary lung cancer there was a slightly higher rate of detection with the mucolytic method than with the routine method: 54 positives from 27 patients compared with 48 positives from 24 patients. Morphological studies using the mucolytic agent indicated that a millipore filter with fixation of cells in suspension produces a satisfactory cell preparation and is valuable in certain problem cases.

Cysteine

Cervical smears.

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Adolescent