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Early evidence from COVID-19 patients and autopsy series indicates that moderate to severe cases are accompanied by damage to the pulmonary endothelium and microcirculation. These data indicate that SARS-CoV-2 infection is particularly avid for lung microvascular endothelium, reflecting endothelial cell infection, inflammation, and focal thrombi occluding the pulmonary circulation leading to progressive fibrosis reminiscent of endothelial-mesenchymal transition. This appears to be a potential mechanism by which COVID-19 causes progressive fibrotic changes, impairment in the pulmonary vasculature, and loss of lung function that persists after acute recovery. Early data from the SARS-CoV-1 epidemic indicated that CD34+ cells in the lung could also be a target of infection and that destruction of lung CD34+ progenitors could account for persistence of pulmonary manifestations. Preclinical studies reveal that restoration of microvasculature in the lung can trigger and sustain regeneration of lung tissue. The microvascular repair function of CD34+ has been documented in preclinical models and multiple human trials in ischemic tissue repair. Accordingly, we designed a clinical trial to evaluate autologous CD34+ cells (CLBS119) for amelioration/repair of COVID-19 lung damage. Subjects must be hospitalized for COVID-19 and have ongoing pulmonary involvement based on room air hypoxia. The study will include approximately 50% of subjects who cannot be liberated from ventilatory support. CD34+ cells will be mobilized with plerixafor and selected from the mononuclear fraction following apheresis. Doses up to 500 x 10 6 cells will be administered IV. Subjects will receive a single administration of cells. Key measures will include assessment of oxygenation, need for supplemental oxygen, pulmonary function assessments, radiographic assessments, and biomarkers. Subjects will be followed for 6 months following administration. Interim findings will be presented.

Background Simulations show that paradoxical anterior femoral slide in conventional dual radius total knee arthroplasty (TKA) is initiated by sudden reduction of the femoral radius from distal to posterior. Therefore, we hypothesized that a new TKA prosthesis design with a gradually reducing femoral radius may minimize the anterior slide in navigation-based in vivo knee kinematics. The purpose of this study was to compare the kinematics of TKA in vivo using a prosthesis with a gradually reducing radius, in comparison with the conventional dual radius design. Methods A retrospective case series report was performed for 12 knees with osteoarthritis using a CT-free navigation system. Six knees received TKA using a prosthesis with a gradually reducing femoral radius (Attune CR) and the other 6 knees underwent TKA using a conventional dual radius design (PFCΣ CR). Anterior-posterior (AP) displacement of the medial and lateral femoral condyles relative to the tibia, and kinematic patterns of the femur throughout the range of motion were compared between the groups. Results The average AP displacement in the Attune CR group indicated no paradoxical anterior movement of both condyles, and kinematic data showed a medial pivot pattern. In contrast, AP displacement in the PFCΣ CR group indicated that both condyles showed paradoxical anterior movement, and kinematically both condyles moved in the same manner, showing a parallel motion pattern. Conclusion TKA using a prosthesis with a gradually reducing radius minimized paradoxical anterior slide in navigation-based in vivo knee kinematics., Highlights • The case series of TKA using a prosthesis with a gradually reducing radius by navigation system was performed. • TKA with a gradually reducing femoral radius minimized paradoxical anterior slide in navigation-based in vivo knee kinematics. • The kinematic pattern was a medial pivot pattern using a prosthesis with a gradually reducing radius.

Background. Costimulatory molecules such as CD28 and B7 are essential for T cell activation, as well as playing a role in the T cell receptor and major histocompatibility complex pathway. It is well known that rejection in allotransplantation is diminished by treatment with CTLA4Ig, but whether a similar effect occurs in xenotransplantation remains to be determined. Methods. In this study, we investigated whether adenovirus-mediated gene transfer with CTLA4Ig cDNA by intravenous injection to the recipient is effective in suppression in hamster-to-rat cardiac xenotransplantation. Results. With CTLA4Ig gene transfer, the duration of gene expression was clearly prolonged, based on reduced production of antiadenovirus antibody and shrinkage of the spleen. The survival of cardiac xenografts was significantly prolonged with CTLA4Ig gene transfer compared to the control graft, and survival with combination use of FK506 and CTLA4Ig gene transfer in xenotransplantation was also significantly prolonged compared to that with CTLA4Ig gene transfer alone. Cessation of the cardiac graft in the combination treatment occurred in parallel with the elevation of antihamster IgM antibodies in rat sera. Conclusions. These results suggest that adenovirus-mediated CTLA4Ig gene transfer is effective for immunosuppression in hamster-to-rat xenotransplantation.

Seven cases of pancreatic serous cystadenoma were examined immunohistochemically and molecular biologically. Six were benign tumors and one was clinically malignant. Immunohistochemical studies were performed with the avidin-biotin peroxidase complex technique on paraffin-embedded tumor tissue and were stained with antibody to carcinoembryonic antigen (CEA), CA19-9, and p53 protein. Two-stage polymerase chain reaction-restriction fragment length polymorphism analysis was used to detect K-ras oncogene mutation at codon 12. No tumor cells were stained with anti-CEA and anti-p53 protein, but two cases were stained focally with anti-CA19-9. One case was benign and one was clinically malignant. In the anti-CA19-9 staining, tumor cells of the benign case were positive only on the apical membrane and supranuclear cytoplasm of the cells, whereas those of the clinically malignant case were positive over the entire surface and cytoplasm of the cells. All seven cases were without K-ras gene mutation. So the features of serous cystadenoma of the pancreas suggest a tumor genesis different from that of ductal adenocarcinoma. They also suggest a relationship between immunohistochemical localizations of CA19-9 in the tumor cells and the biological behavior of the tumor itself.

In this study, we attempted to detect K-ras point mutations by means of two-stage polymerase chain reaction/ restriction fragment length polymorphism (PCR/RFLP) to diagnose micrometastases in paraaortic lymph nodes of patients with pancreatic adenocarcinoma. Main carcinoma tissues and corresponding lymph nodes in the paraaortic region were obtained from 15 patients who underwent extended radical surgery including the wide dissection of lymph nodes and who were diagnosed as lymph node negative by routine histological examination. DNA was extracted from the tissue specimens, and PCR/RFLP analysis was used to detect K-ras oncogene mutations at codon 12. Thirteen of the primary tumors were found to have K-ras mutations. In eight of the 13 cases, 42 of the 101 lymph nodes showed K-ras point mutations in the paraaortic lymph nodes. These results suggested that PCR/ RFLP analysis is potentially highly sensitive for the detection of micrometastases in lymph nodes and that it may be useful in reaching an accurate assessment of the lymphatic dissemination of pancreatic adenocarcinoma at the molecular level.

Peritoneal metastases are the second most common site of involvement, following the liver, in pancreatic cancer. Thus, we performed peritoneal washing cytology at laparotomy to diagnose accurately the intraperitoneal spread of carcinoma cells to determine the appropriate therapy. Peritoneal washings were collected at laparotomy from 20 Japanese pancreatic carcinoma patients at Nagoya University Hospital between April 1993 and December 1994. From centrifuged deposits, we examined the cytology by three methods as follows. The first method was conventional cytology, including May-Grünwald and Giemsa, Papanicolaou, periodic acid-Schiff, and Alcian blue. The second method was immunocytochemical staining, using antibodies to carbohydrate antigen (CA19-9) and carcinoembryonic antigen. After extracting DNA from the remaining pellet, we studied the last method, detecting K-ras point mutation, by two-step polymerase chain reaction and restriction fragment length polymorphism analysis. In two cases, peritoneal metastases were macroscopically recognized, and the results of all three methods were positive. In the two other cases, where peritoneal dissemination was not macroscopically recognized, the judgments of conventional cytological study and detecting K-ras point mutation were negative. However, a few malignant cells were found by the immunocytochemical staining method. Judging from their clinical course, the positively stained cells were suggestive of malignancy. At present, the immunocytochemical staining method is the most sensitive of these three methods in peritoneal washing cytology. However, preserving DNA is suitable for repeated examination, and a modified method can be applied. If the sensitivity increases, the method of detecting K-ras has the potential to become the standard for peritoneal washing cytology in pancreatic cancer.

The accurate diagnosis of inferior vena cava infiltration is important not only for preoperative staging but also for performing surgery for hepatic tumor involving the inferior vena cava (IVC). We investigated the diagnostic value of intracaval endovascular ultrasonography (ICEUS) in the diagnosis of invasion of the IVC by a prospective study of 30 consecutive patients with hepatic tumors with possible invasion of the IVC. The procedure was performed using an 8F, 20-MHz intravascular ultrasonography (US) from the right femoral vein. Twenty-nine of the 30 patients underwent surgery, and the tumor was resected in 25 cases, including 3 cases of combined resection of the IVC. The diagnostic criterion for IVC infiltration with ICEUS was obliteration of a single echogenic layer of the IVC wall or intracaval tumor mass. The results of ICEUS were compared with those of computed tomography (CT), cavography, conventional US, and intraoperative US. Vascular invasion was identified in 7 of 30 cases and was subsequently confirmed by pathological examination of four resected specimens, including one autopsy and two operative findings. The sensitivity, specificity, and overall accuracy of ICEUS for the diagnosis of the IVC invasion was 100%, 95.8%, and 96.7%, respectively, against 85.7%, 60.8%, and 66.7% for CT, and 71.4%, 73.9%, and 73.3%, respectively, for cavography. The sensitivity, specificity, and overall accuracy of conventional US was 87.5%, 59%, and 66.7%, respectively; those of intraoperative US were 100%, 81.8%, and 86.2%, respectively. ICEUS is a useful technique that can precisely evaluate the IVC for possible hepatic tumor invasion.

Information on genetic abnormalities in primary hyperparathyroidism has accumulated gradually. Genetic alterations responsible for tumorigenesis have been identified in multiple endocrine neoplasia types 1 and 2. Point mutations in a calcium-sensing receptor gene were recently found to be responsible for familial hypocalciuric hypercalcaemia and neonatal severe hyperparathyroidism. Evidence has been provided that abnormalities of cell cycle regulation participate at tumorigenesis in parathyroid adenoma and carcinoma. Clonal analysis has shown that in renal hyperparathyroidism the parathyroid glands initially grow diffusely and polyclonally, after which foci of nodular hyperplasia are transformed to monoclonal neoplasia. Somatic changes of specific genes have been suspected of being responsible for parathyroid tumorigenesis in renal hyperparathyroidism. However, the genetic loci responsible for the frequent monoclonality largely remain to be identified, and heterogeneous genetic abnormalities may contribute to the progression of secondary parathyroid hyperplasia.

This study was designed to clarify the effects of changes in liver tissue glutathione (GSH) concentration on postischemic liver injury together with the effects of gamma-glutamylcysteine ethyl ester (GCE), a prodrug of GSH, and GSH. Rats were pretreated with GSH (50 mg/kg, i.v.), or GCE (50 mg/kg, i.v.), or untreated. In each rat, liver was isolated, and liver mitochondria were prepared after 2 h of ischemia or 1 h of reperfusion following 2 h of ischemia. Mitochondrial function was measured polarographically. Liver adenine nucleotide concentrations were also determined using high-performance liquid chromatography. Liver tissue GSH, an oxidized form of glutathione (GSSG) concentrations, and activities of GSH peroxidase and GSSG reductase were determined enzymatically. Liver hypoxanthine and xanthine concentrations were determined by HPLC. Liver tissue concentration of lipid peroxide was measured. Leakages of aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), and adenine nucleotides into the hepatic vein after reperfusion were also measured. Administration of GCE improved the recovery of mitochondrial function and maintained tissue GSH concentration concomitantly. Increases in liver lipid peroxide concentration after reperfusion, and leakage of liver cell enzymes and adenine nucleotides were mitigated by administration of GCE. Administration of GSH itself failed to maintain tissue GSH concentration and had no protective effects. From these results, it is concluded that in the postischemic process, free radical formation might be enhanced, and the radical scavenging system deteriorated. To enhance the radical scavenging system is a possible maneuver to prevent radical-related cell damage associated with reperfusion, because pharmacological reduction of breakdown of ATP to hypoxanthine and xanthine seems to be difficult. GCE maintained liver GSH concentrations and mitigated postischemic liver injury, concomitantly. Clinical use of GCE might be recommended.

The discovery of cyclosporine has had a significant impact on preventing the rejection of transplanted organs in humans. In this study, we present another positive aspect of cyclosporine. Rats were pretreated with cyclosporine (10 mg/kg, i.v.), or untreated. After 2-hr ischemia or 1 hr of reperfusion following 2-hr ischemia, livers were isolated and liver adenine nucleotide concentrations were determined. Liver mitochondria were prepared and their function was estimated polarographically. Leakage of AST, ALT, LDH, and adenine nucleotides into the hepatic vein just after reperfusion was also measured. Cyclosporine treatment did not affect ischemia-induced mitochondrial dysfunction, nor did it prevent the associated decrease in adenosine triphosphate concentration. However, treatment with cyclosporine accelerated the recovery of mitochondrial function and of tissue adenosine triphosphate concentrations. Cyclosporine treatment also mitigated leakage of AST, ALT, LDH, and adenine nucleotides after reperfusion. These results indicate that cyclosporine shows a potent protective effect on ischemia-reperfusion-related liver injury.

The relationship between operative findings of hepatoma and the postoperative prognosis was studied to clarify indications for adjuvant hepatic arterial chemotherapy after hepatectomy. The results of adjuvant hepatic arterial chemotherapy using 0.4 mg/kg of doxorubicin and 0.12 mg/kg of mitomycin C and infusion of 5-fluorouracil were reported. One hundred sixty patients who had undergone hepatectomy for hepatoma were studied. In the operative findings of hepatoma, with a surgical margin of less than 10 mm, intrahepatic metastasis, tumor embolus in the second or more proximal branch of the portal vein, or lack of capsule formation related to the prognosis were the risk factors for recurrence. In 132 patients with these risk factors the survival rate of 19 patients with adjuvant arterial chemotherapy was significantly higher than for the 113 patients without it. Adjuvant hepatic arterial chemotherapy thus may be an effective therapy and should be studied prospectively in patients undergoing hepatectomy for high-risk hepatoma.

We retrospectively examined the effect of HLA-DRB1 matching at the DNA level compared with serological HLA-DR matching on acute rejection and graft survival in patients who underwent primary cadaveric renal transplantation. For patients with serological HLA-DR zero mismatch, the incidence of acute rejection in patients with zero DRB1 mismatch (3/20; 15%) was significantly lower than in those with one or two DRB1 mismatches (10/21; 48%). Five-year graft survival in patients with zero DRB1 mismatch was 100%, whereas that in those with one or two DRB1 mismatches was 76%, although the difference was not statistically significant. The fact that HLA-DRB1 matching at the DNA level influenced incidence of graft rejection after cadaveric renal transplantation is analogous to results in living-related renal transplantation. It is suggested that avoidance of mismatching for DRB1 alleles at the DNA level in recipient selection of cadaveric renal transplantation leads to an improvement of graft outcome.

We analyzed the genotype for HLA-DRB1 alleles by digestion of polymerase chain reaction-amplified genes with the restriction endonucleases (PCR-RFLP) method to investigate the influence of HLA-DR antigen "splits" at the DRB1 gene level on the incidence of acute graft rejection in the renal transplant. For all patients, the incidence of acute rejection was proportional to the number of the serological HLA mismatch (0% in patients with two-haplotype match; 18% with HLA-A, -B, and -DR zero mismatch; 33% with HLA-DR zero mismatch; and 48% with HLA-DR one mismatch). For the patients with serological HLA-DR zero mismatch, the incidence of acute rejection in patients with HLA-DRB1 one mismatch (10/13: 77%) was significantly higher than that in those with zero mismatch (2/27: 7%). It was concluded that genotyping for HLA-DRB1 alleles would be beneficial in predicting acute rejection in patients with serological HLA-DR zero mismatch, although no difference was noted in the graft survivals.

Three noninvasive imaging methods, CT, scintigraphy with /sup 201/TlCl and /sup 99m/TcO4-, and ultrasonography, were performed on 36 patients with chronic renal failure and secondary hyperparathyroidism. The patients subsequently underwent total parathyroidectomy and parathyroid autograft. The detection rates of the three methods for the 143 excised parathyroid glands were compared according to gland weight and location. Computed tomography detected 53.8% of all glands and 77.6% of 76 glands weighing more than 500 mg. Scintigraphy detected 51.0% of all glands and 77.6% of glands heavier than 500 mg. Ultrasonography detected 42.7% of all glands and 65.8% of glands heavier than 500 mg. The detection rate of upper glands was best with CT (53.5 and 87.9%): that of lower glands was best with scintigraphy (62.0 and 78.6%). Although the combination of the three methods diagnosed 66.4% of all glands and 89.5% of glands heavier than 500 mg, CT and scintigraphy, the best two combinations, visualized 64.3 and 88.2%.

Computed tomography (CT) of the neck and mediastinum was performed in 15 patients with secondary hyperparathyroidism. Twenty-eight of 32 excised parathyroid glands weighing more than 500 mg were visualized preoperatively (87.5%). The visualization of enlarged parathyroid glands is valuable not only for localization, but also for unequivocal evidence of hyperparathyroidism.

Bradykinin, a potent pain-producing substance, injected into the common iliac artery of the rat produced flexor reflexes of the hind-limb. The bradykinin-induced response was reduced following the repetition of such noxious stimuli in some male Sprague-Dawley rats classified as the noxious-adaptable group, while the reduction of bradykinin-response did not occur in the majority of the same strain rats in the noxious-non-adaptable group. Naloxone in doses of 0.1 – 2.0 mg/kg restored the flexor reflexes to the noxious stimulation, in a dose dependent manner, in the former group; ED 5 0 value being 0.61 mg/kg. On the other hand, naloxone in doses up to 5.0 mg/kg produced no hyperalgesic effect in the latter group. Thus, genetic variation in endogenous opioid systems has to be considered.