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Biomedical subjects

K Washington

Publications and source records attributed to K Washington.

44 records · Page 3Linked to original sources

Helicobacter pylori-like microorganisms and chronic active gastritis in ferrets.

To determine the prevalence and histology of Helicobacter pylori (HP) associated gastritis in young ferrets, we examined 36 normal 2- to 4-month old ferrets. Identification of HP-like microorganisms included Warthin Starry stains of tissue sections, rapid urease test on fresh tissue, and culture. HP-like microorganisms were found in the stomachs of 35/36 ferrets. The highest density of microorganisms was seen in the antrum, where HP-like microorganisms were present in the pits and in deep glands. HP-like microorganisms were also seen in the cardia and on the foveolar epithelium of the fundus, but not in fundic glands. Chronic active gastritis was seen in all animals with HP-like microorganisms, but involved only the antrum. The distal antrum was most severely involved. One animal had no evidence of HP-like microorganisms on tissue sections or by rapid urease test. Gastric tissue sections from this animal showed only minimal infiltration of the lamina propria by polymorphonuclear leukocytes and lymphocytes. Gastritis associated with HP-like microorganisms is common in ferrets and is acquired at a young age. It is associated with chronic active antral gastritis similar to that seen in humans, suggesting that ferrets should provide a useful experimental model for HP-associated gastritis and peptic ulcer.

Animals↗

Dye binding probes of lipid-binding structures. An investigation of 2-p-toluidinylnaphthylene-6-sulfonate binding to human and bovine prothrombin and fragment 1 in the presence and absence of calcium and magnesium ions.

TNS (2-p-toluidinylnaphthylene-6-sulfonate) binds to human and bovine prothrombin and Fragment 1 in the absence and presence of added Ca2+. The stoichiometry of TNS binding is 1:1 for human and bovine prothrombin and Fragment 1. The Ca2+-dependence of the fluorescence of TNS bound to bovine prothrombin Fragment 1 yields a modified Hill plot slope of 2.7, which is consistent with the slope obtained by monitoring the Ca2+ dependence of protein fluorescence quenching, CD changes and phospholipid binding. Mg2+ has have no effect on the fluorescence of TNS-prothrombin fluorescence. TNS binding to the amino-terminal region of prothrombin is the first relatively simple probe of the subtle and complex relationship which exists between protein structure and phospholipid binding.

Animals↗

Inflammatory cloacogenic polyp in a child: part of the spectrum of solitary rectal ulcer syndrome.

A 15-year-old boy with Marshall-Smith syndrome presented with increased frequency and urgency of stooling, hematochezia, and rectal pain. A polypoid mass was found at the anorectal junction and excised. Microscopically, the lesion was covered by both squamous and columnar mucosa. It was villiform in configuration with focal ulceration and strands of smooth muscle in the lamina propria. These features are characteristic of an inflammatory cloacogenic polyp, a lesion not previously reported in the pediatric age group. Inflammatory cloacogenic polyp is related to solitary rectal ulcer syndrome and is most likely due to prolapse of the anorectal transition zone. Although rare in this age group, solitary rectal ulcer and its variants should be considered in the differential diagnosis of anorectal and rectal lesions in the pediatric patient.

Adolescent↗

Pathology of the liver in severe combined immunodeficiency and DiGeorge syndrome.

Review of liver biopsy or autopsy material from 33 patients with severe combined immunodeficiency or combined immunodeficiency and four patients with DiGeorge syndrome revealed a wide range of hepatic pathology. The most common abnormality was graft-versus-host disease (16 patients), followed by viral infection (4 patients had adenovirus hepatitis, 3 had cytomegalovirus hepatitis). Centrilobular fibrosis with or without veno-occlusive disease was seen in five patients. Three patients had nonspecific hepatitis, four had changes attributed to total parenteral nutrition, and two had lymphoproliferative disorders involving the liver. Both patients with lymphoproliferative disorders had received transplants. Two patients had resolving necrosis probably secondary to non-A, non-B hepatitis. One had atypical mycobacterial infection. Hemosiderosis was a common nonspecific abnormality, seen in nine patients. All patients with hepatic graft-versus-host disease had received transplants or nonirradiated blood products. Hepatic graft-versus-host disease varied in severity from hepatic necrosis with destruction of both large and small bile ducts in a transfusion-associated case to subtle damage to interlobular bile ducts. Even minimal bile duct changes correlated with the clinical impression of graft-versus-host disease in these patients. Late chronic graft-versus-host disease was not seen in any patient, although acute graft-versus-host disease sometimes occurred late after transplant.

Bone Marrow Transplantation↗

Ki-1+ large-cell anaplastic lymphoma after Ewing sarcoma.

PURPOSE: A large cell anaplastic lymphoma that developed after treatment of a Ewing sarcoma (ES) is described. PATIENT: An 11-year-old girl with a pelvic ES developed a large cell, Ki-1+, anaplastic lymphoma in the same anatomic location 10 months after multimodal therapy. RESULTS: ES recurred in the primary site 16 months after allogeneic marrow transplantation and 3.5 years after initial diagnosis, but the patient remains in remission from her lymphoma. CONCLUSION: The occurrence of lymphoma and ES in a short time interval in the same patient is very unusual. Whether etiologic factors other than chemoradiotherapy, including genetic disposition, play a role remains to be elucidated.

Antineoplastic Combined Chemotherapy Protocols↗

RT in situ PCR for the detection of mRNA transcripts of Fas-L in the immune-privileged placental environment.

Rapid and reproducible detection of RNA in cells and tissue sections is routinely accomplished using in-situ hybridization technique provided that the target number of mRNA copies is above a minimum number. Detection of low copy transcripts is problematic when threshold detection occurs below clear signal resolution or alternatively, when technical problems result in background noise which occludes clear signal. RT in-situ PCR methodology utilizes both the power and specificity of PCR to amplify target whose localization is subsequently detected at the cellular level. RT in-situ PCR methods routinely involve a two-step methodology. mRNA copies are initially transcribed into cDNA. This step is followed by a separate PCR step wherein amplification of the newly synthesized cDNA takes place. A simplified one-step procedure biochemically compartmentalizes these sequential steps within a single applications methodology using the enzyme rTth. This method was successfully applied to detect and localize mRNA transcripts for Fas ligand within the immune privileged placental environment and to provide verification of immunohistochemical localization of gene product.

Base Sequence↗