Jagjit Singh

Identification, cellular localization, isolation, and characterization of human Clara cell-specific 10 KD protein.

Human lung lavage proteins were fractionated by centrifugation and molecular sieving. An antiserum to the post-albumin fraction of the soluble proteins reacted with a 10 KD protein and this protein was isolated by conventional chromatography. The protein, which has a pI of 4.8, consists of two 5 KD polypeptides and is rich in glutamic acid, leucine, serine, and aspartic acid amino acids. The protein does not bind to concanavalin A, pancreatic elastase, leukocyte elastase, or trypsin, and lacks anti-protease activity. It constitutes about 0.15% of the soluble proteins in lung lavage. Antibodies to the 10 KD protein specifically and exclusively stain Clara cells in human, dog, and rat. Staining of granules of Clara cells was prominent in the distal bronchioles; however, the non-ciliated cells of respiratory bronchioles did not stain for the 10 KD protein. This 10 KD protein appears in fetal lungs at 21 weeks of gestation, and was present in about 10% of the primary pulmonary adenocarcinomas. As a specific marker for Clara cells, this protein could be useful in the study of development, regulation of secretion, and pathobiology of these cells.

Pig kidney graft survival in a baboon for 136 days: longest life‐supporting organ graft survival to date

The longest survival of a non‐human primate with a life‐supporting kidney graft to date has been 90 days, although graft survival > 30 days has been unusual. A baboon received a kidney graft from an α‐1,3‐galactosyltransferase gene‐knockout pig transgenic for two human complement‐regulatory proteins and three human coagulation‐regulatory proteins (although only one was expressed in the kidney). Immunosuppressive therapy was with ATG+anti‐CD20mAb (induction) and anti‐CD40mAb+rapamycin+corticosteroids (maintenance). Anti‐TNF‐α and anti‐IL‐6R were administered. The baboon survived 136 days with a generally stable serum creatinine (0.6 to 1.6 mg/dl) until termination. No features of a consumptive coagulopathy (e.g., thrombocytopenia, decreased fibrinogen) or of a protein‐losing nephropathy were observed. There was no evidence of an elicited anti‐pig antibody response. Death was from septic shock (Myroides spp). Histology of a biopsy on day 103 was normal, but by day 136, the kidney showed features of glomerular enlargement, thrombi, and mesangial expansion. The combination of (i) a graft from a specific genetically engineered pig, (ii) an effective immunosuppressive regimen, and (iii) anti‐inflammatory agents prevented immune injury and a protein‐losing nephropathy, and delayed coagulation dysfunction. This outcome encourages us that clinical renal xenotransplantation may become a reality.

Ultrastructural localization of rat Clara cell 10 KD secretory protein by the immunogold technique using polyclonal and monoclonal antibodies.

Using a monoclonal antibody and affinity-purified polyclonal antiserum against a 10 KD protein isolated from rat pulmonary lavage, we have localized the protein within Clara cells by a post-embedment protein A-gold technique. The gold particles were localized over the secretory granules of rat Clara cells. Ultrastructural immunolocalization was abolished when the primary antibodies were previously absorbed with purified 10 KD protein. Other pulmonary cells, including type II pneumocytes and ciliated cells, were negative with this technique. These results demonstrate the presence of the 10 KD protein in the secretory granules of the Clara cell and support the concept that this protein constitutes a specific and unique secretory product of Clara cells.

Bleeding polyp of the osseous nasal septum: a rarely seen lesion.

The nasal septal hemangioma or “bleeding polyp,” first reported by Ash and Old’ in 1950, is an uncommon lesion of the nasal cavity. Histological confirmation of the diagnosis is crucial to make the appropriate diagnosis and institute definitive treatment because these tumors often mimic malignancy. We present an unusual case of a patient with a nasal septal hemangioma that originated on the osseous nasal septum rather than the more commonly described anterior cartilaginous septum. Computed tomography (CT) and early biopsy assisted in definitive treatment planning.

Expression of SSEA-1 (Lewisx) on Transitional Cell Carcinoma of the Bladder

The expression of stage-specific embryonic antigen 1 (SSEA-1) in transitional cell carcinomas of the bladder (TCCB) has been reported to correlate with tumor grade and the likelihood of lymphatic metastases. We examined the expression of this antigen in TCCBs to evaluate if staining correlated with grade, stage, recurrence, progression and response to intravesical chemotherapy. We studied the expression of SSEA-1 in TCCBs from 74 patients by staining with two different monoclonal antibodies (Mabs), P-12 and anti-SSEA-1, to evaluate if staining correlated with grade, stage and tumor recurrence. Staining was considered as positive or negative irrespective of the intensity of staining. Extent of tumor staining was measured in quartiles of 100% (25, 50, 75 and 100). Follow-up was available in 47/74 (63%) patients and ranged from 6 months to 13 years (median 2 years). Staining with one or both Mabs was observed in 57/75 (76%) tumors. None of the grade I tumors showed > 50% staining while 26% of grade II and only 33% of grade III tumors showed staining of > 50% of cells. 21% of patients whose tumors showed staining with both Mabs were free of recurrence after resection of the primary tumor; 41% of patients with tumors staining negative with both Mabs showed no recurrence. Expression of SSEA-1 does correlate with tumor recurrence especially in grade II tumors, but the correlation is not very strong (0.05 < p < 0.1). Expression of this antigen is a weak indicator of recurrence in superficial TCCBs.

Transplantation of hepatocytes from genetically engineered pigs into baboons

Some patients with acute or acute‐on‐chronic hepatic failure die before a suitable human liver allograft becomes available. Encouraging results have been achieved in such patients by the transplantation of human hepatocyte progenitor cells from fetal liver tissue. The aim of the study was to explore survival of hepatocytes from genetically engineered pigs after direct injection into the spleen and other selected sites in immunosuppressed baboons to monitor the immune response and the metabolic function and survival of the transplanted hepatocytes.

MYROIDES INFECTION IN A BABOON AFTER PROLONGED PIG KIDNEY GRAFT SURVIVAL.

Background Immunosuppressed patients and experimental nonhuman primates are at risk of opportunistic infection. We report a Myroides spp. infection in an immunosuppressed baboon that had received a life-supporting kidney from a genetically engineered pig. Case Report The baboon received a costimulation blockade-based immunosuppressive regimen as well as 2 anti-inflammatory agents (tocilizumab and etanercept). Although the pig kidney functioned well, approximately 4 months after the transplantation, the baboon became less active and ate and drank poorly. On day 136, it collapsed and died despite inotropic and fluid support. A blood culture drawn before death grew Myroides spp. Discussion and Conclusions To our knowledge, Myroides spp. has not been reported as a cause of opportunistic infection in either patients with organ allotransplants or experimental animals. We summarize what is known about this rare organism and suggest it should be considered in any immunocompromised patient or animal. In the present case, we suggest the baboon died of circulatory shock following infection through an indwelling intravenous catheter.