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Biomedical subjects

F W Chandler

Publications and source records attributed to F W Chandler.

At least 37 records · Page 2Linked to original sources
PubMed1992

Detection of Borrelia burgdorferi in laboratory-reared Ixodes dammini (Acari: Ixodidae) fed on experimentally inoculated white-tailed deer.

Larvae and nymphs of Ixodes dammini Spielman, Piesman, Clifford & Corwin from a laboratory colony were fed on two white-tailed deer, Odocoileus virginianus (Zimmerman) inoculated with either the SH2-82 or JD-1 strains of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner. Ticks were exposed to one deer 43 and 69 d after inoculation of the spirochete and to a second deer 35 and 61 d after inoculation. Polymerase chain reaction assays amplified the 158 bp OspA DNA target sequence in 11.1% (n = 9) of fed larvae and 3.3% (n = 30) of nymphs from the deer inoculated with the SH2-82 strain, and 22.7% (n = 22) of larvae and 0% (n = 21) of nymphs from a second deer inoculated with the JD-1 strain of B. burgdorferi. One of three females derived from nymphs fed on one of the inoculated deer showed presence of B. burgdorferi DNA, but none of four males was positive. Experimentally inoculated deer can serve as a source of at least two geographic strains of B. burgdorferi to I. dammini larvae and nymphs for at least several weeks.

Animals↗
PubMed1992

Detection of Borrelia burgdorferi in human blood and urine using the polymerase chain reaction.

We investigated the use of the polymerase chain reaction (PCR) to detect Borrelia burgdorferi strain B-31 in human blood and urine experimentally inoculated with 5 and 1 borreliae/cm3, respectively, and to biotinylate a DNA probe specific for B. burgdorferi in the dot blot and Southern blot assays. When the blood and urine samples were subjected to PCR, a 370-bp amplified product was consistently visible on agarose gel electrophoresis after 30 and 45 cycles, respectively. The total human genomic DNA extracted from a 1-cm3 sample of inoculated blood was approximately 6.25 micrograms, and the total amount of B. burgdorferi DNA was estimated to be 0.01 pg/6.25 micrograms of the human DNA. For PCR, 2.5 micrograms of human DNA which contained the equivalent of 0.004 pg of borrelia DNA (approximately two borreliae) were used for enzymatic amplification. When 1/20 or 1/10 of the PCR-amplified products were used either for dot blot or Southern blot hybridization, the accessible copies of amplified B. burgdorferi DNA were sufficient for detectable hybridization to occur. PCR amplification of B. burgdorferi DNA in clinical specimens followed by dot blot hybridization may be a valuable adjunct or alternative to current but inadequate laboratory methods for the diagnosis of Lyme disease.

Base Sequence↗
PubMed1991

Chlamydia trachomatis in chronic abacterial prostatitis: demonstration by colorimetric in situ hybridization.

Twenty-three transurethral resected prostate specimens with histologic evidence of chronic abacterial prostatitis were evaluated by colorimetric in situ hybridization for evidence of Chlamydia trachomatis. Intracellular chlamydia bodies were detected in seven of 23 cases (30.4%). In five of seven positive cases, chlamydia inclusion bodies were present within both epithelial cells and intraluminal histiocytes. In two of seven positive cases, extracellular chlamydia bodies were identified in conjunction with intraepithelial inclusions. In only one case were extraductal, extraacinar, intrahistiocytic inclusion bodies observed. Our study confirms previous reports implicating C trachomatis as an etiologic agent in chronic abacterial prostatitis, and underscores the applicability of DNA probes for the detection and identification of C trachomatis in routinely fixed, paraffin-embedded tissues.

Chlamydia Infections↗
PubMed1991

Differential expression of c-myc and H-ras oncogenes in Barrett's epithelium. A study using colorimetric in situ hybridization.

To determine the role of c-myc and H-ras in progressive, dysplastic Barrett's mucosa (BM), and the usefulness of these oncogenes as markers for dysplastic lesions at high risk for malignant transformation, sequential formaldehyde solution-fixed, paraffin-embedded biopsy specimens that were obtained from 12 patients with BM were evaluated by in situ hybridization with the use of biotinylated complimentary DNA probes. Nine of the patients were taken from a previous prospective study. Four of these nine patients had dysplasia, and adenocarcinoma had developed in two of them; five had nondysplastic BM only. Two additional patients had adenocarcinoma, but their initial biopsy specimens had revealed dysplasia. One additional patient had intermediate-grade dysplasia. The intensity of oncogene expression was quantified by computerized color-image analysis. Enhanced c-myc expression of approximately equal intensity was consistently observed in all grades of dysplasia and carcinoma. H-ras was also consistently expressed in higher grades of dysplasia and carcinoma but not in low-grade dysplasia. Neither c-myc nor H-ras expression was detected in nondysplastic BM. The expression of H-ras in dysplastic BM appears to be a helpful marker for identifying which dysplastic lesions will progress to carcinoma.

Chronic Disease↗
PubMed1990

Focal hepatic candidiasis with perihepatic adhesions: laparoscopic and immunohistologic diagnosis.

Two patients developed fever, cholestasis, and neutropenia following chemotherapy for acute leukemia. Computed tomographic scans of the liver were nondiagnostic, but peritoneoscopy in each case showed diffuse studding of the liver surface with white plaques. Microbiological cultures of the biopsy specimens were negative, but direct immunofluorescence stains of deparaffinized sections of the biopsies confirmed candidiasis. Follow-up laparoscopy in 1 patient after 2 mo of treatment with amphotericin B showed development of diffuse perihepatic adhesions. Peritoneoscopy is valuable in the diagnosis and management of focal hepatic candidiasis, and an etiologic diagnosis can be provided by immunohistology when microbiological culture of the biopsy specimen is negative or unavailable.

Adult↗
PubMed1990

Giant forms of Blastomyces dermatitidis in the pulmonary lesions of blastomycosis. Potential confusion with Coccidioides immitis.

Typical yeast-phase cells of Blastomyces dermatitidis have a characteristic appearance in tissue sections. Fungal morphologic variation occurs infrequently in the lesions of blastomycosis, yet it can complicate the differential diagnosis, particularly if fresh tissue is not available for microbiologic culture. The authors report a case of pulmonary blastomycosis, confirmed by culture and direct immunofluorescence, in which some of the yeast-like cells were abnormally large. These giant yeast-like cells exceeded the size range accepted for the tissue forms of B. dermatitidis; therefore, coccidioidomycosis was considered initially in the differential diagnosis. Otherwise characteristic morphologic features of these cells, in particular multinucleation and the production of broad-based blastoconidia, helped resolve the differential diagnosis. The diagnosis can be confirmed by direct immunofluorescence or microbiologic culture.

Blastomyces↗
PubMed1990

Enhanced expression of c-myc and H-ras oncogenes in Letterer-Siwe disease. A sequential study using colorimetric in situ hybridization.

Tissues from two patients with disseminated histiocytosis X (Letterer-Siwe disease) in which histiocytosis X cells exhibited histologic and cytologic features of malignancy were evaluated by in situ hybridization with the use of biotinylated nucleic acid probes to c-myc and H-ras oncogenes. Enhanced expression of these oncogenes was observed in mononucleated and multinucleated cells of histiocytosis X in the terminal proliferative phase but not in the early quiescent phase of Letterer-Siwe disease in both patients. Our findings indicate that deregulation of c-myc and H-ras in histiocytosis X are late events that likely confer a selective growth advantage to histiocytosis X cells.

DNA Probes↗
PubMed1989

Cerebral phaeohyphomycosis caused by Chaetomium globosum in a renal transplant recipient.

A 32-year-old male patient developed headaches, vomiting, blurring of vision, and focal seizures of the left side of the face 2 months after a renal transplant. He developed a brain abscess and died. Direct KOH examination of the brain tissue demonstrated hyaline as well as dematiaceous, septate hyphae. Histologic examination of brain sections revealed polymorphous fungal elements consisting of septate, dark-pigmented hyphae, intercalary and terminal swollen fungal cells, and budding yeastlike cells characteristic of phaeohyphomycosis. Chaetomium globosum was isolated from the brain tissue on all of the fungal media used. This case represents the first histologically and culturally documented phaeohyphomycotic brain infection caused by C. globosum.

Adult↗
PubMed1989

Demonstration of human immunodeficiency virus by colorimetric in situ hybridization: a rapid technique for formalin-fixed paraffin-embedded material.

A colorimetric method of in situ hybridization has been developed for the rapid detection of human immunodeficiency virus (HIV) in formalin-fixed paraffin-embedded material. Following optimization of digestion conditions, biotin-labeled DNA probes are detected with an alkaline phosphatase conjugate. The method is verified using fixed paraffin-embedded cell blocks of HIV-infected and uninfected lymphocyte cell cultures. Hybridization specifically detects both viral RNA and proviral DNA. Formalin fixation for intervals up to 21 d did not significantly hamper the signal under the appropriate digestion conditions; however, Trump's fixation for even 12 h greatly reduced the intensity of the hybridization. This technique for in situ hybridization is amenable to automation, provides results within 6 h, and results in good morphologic preservation. A key feature of the technique is the use of human placental DNA as an endogenous positive control to optimize the empirically determined conditions for protein digestion.

Cells, Cultured↗
PubMed1988

Pathogenesis of rabies virus from a Danish bat (Eptesicus serotinus): neuronal changes suggestive of spongiosis.

Rabies virus strains isolated from a European bat (Eptesicus serotinus) in Denmark (DBV), a North American big brown bat (Eptesicus fuscus) in New York State (NY-bat), and a human in South Africa (Duvenhage strain (DUV-1) were studied by using a panel of monoclonal antibodies and by inoculating mice, cats, and dogs. The ten Danish virus isolates from the same bat species reacted identically with a panel of monoclonal antibodies. Immunofluorescence, monoclonal antibody, and histopathologic studies showed that the Danish bat isolates were similar to Duvenhage, and to some degree, to classical rabies virus. All isolates produced fatal infections in mice when inoculated by the intracerebral, footpad, and oral routes. Dogs and cats inoculated intracerebrally with the DBV and DUV-1 virus strains died of rabies-like illnesses within 10 days. Although no dogs that were inoculated intramuscularly or intravenously showed signs of disease, all developed neutralizing antibodies and resisted challenge with lethal dose of street rabies virus. All dogs inoculated with the NY-bat virus, with the exception of those inoculated intravenously, showed classical signs of rabies and one of the intramuscularly inoculated dogs recovered. Cats inoculated intramuscularly also died of rabies-like illness within 15 days. At necropsy, rabies antigen was detected by immunofluorescence in frozen sections of several organs, including brain and salivary glands. Histopathologic and electron microscopic studies of the central nervous system of mice, dogs and cats that died of DBV infection showed neuronal cytoplasmic changes considered to be a form of spongiosis.

Animals↗
PubMed1988

Use of the avidin-biotin peroxidase system to detect rabies antigen in formalin-fixed paraffin-embedded tissues.

We stained rabies-infected nervous and salivary-gland tissues fixed in formalin or acetone and embedded in paraffin with the avidin-biotin peroxidase system. With this system, rabies-virus antigen was detected in neurons, glandular acinar cells, and vascular endothelial cells more effectively than by immunofluorescence, especially when tissues were enzyme-digested with pronase before immunoperoxidase staining. The avidin-biotin peroxidase system should be useful for routine diagnosis, retrospective studies of rabies, and identification of specific cells involved in the spread of virus in rabies-infected hosts.

Animals↗
PubMed1988

First case of subcutaneous zygomycosis caused by Saksenaea vasiformis in India.

The first case of subcutaneous zygomycotic infection caused by Saksenaea vasiformis in a rice mill worker from India is described. The infection, confined to the man's left foot, showed multiple draining sinuses, inflammation, and intermittent low-grade fever following a crushing injury when a log fell on his foot. Histopathologic examination of two biopsy specimens, taken at 3-wk intervals, revealed the presence of broad, sparsely septate, branched, hyaline hyphae characteristic of a zygomycete. When they were grown on a nutritionally deficient medium, two cultures isolated from the biopsied tissues formed numerous, vase-shaped sporangia typical of S. vasiformis. Necrosis of the affected area led to amputation of the fore part of the foot. A split thickness graft was well accepted, and treatment with potassium iodide, following the graft, cured the infection.

Adult↗