Liver repopulation with xenogenic hepatocytes in B and T cell-deficient mice leads to chronic hepadnavirus infection and clonal growth of hepatocellular carcinoma

To investigate host and viral mechanisms determining hepadnaviral persistence and hepatocarcinogenesis, we developed a mouse model by transplanting woodchuck hepatocytes into the liver of mice that contain the urokinase-type plasminogen activator transgene (uPA) and lack mature B and T lymphocytes due to a recombination activation gene 2 (RAG-2) gene knockout. The woodchuck hepatocytes were transplanted via intrasplenic injection and were found to integrate into the recipient mouse liver cord structure. Normal adult woodchuck hepatocytes proliferated and reconstituted up to 90% of the uPA/RAG-2 mouse liver. uPA/RAG-2 mice containing woodchuck hepatocytes were infectable with woodchuck hepatitis virus (WHV) and showed WHV replication for at least 10 months with titers up to 1 × 10¹¹ virions per ml in the peripheral blood. WHV-infected hepatocytes from chronic carrier woodchucks also established a persistent infection in uPA/RAG-2 mice after an 8- to 12-week lag period of viremia. Although WHV envelope, core, and X proteins were produced in the uPA/RAG-2 mice, no inflammatory host immune response was observed in the liver of WHV-replicating mice. A first antiviral test demonstrated a greater than four orders of magnitude drop in WHV titer in response to interferon α treatment. WHV replication was up-regulated by dexamethasone treatment. Comparison of precancerous lesions in donor woodchucks versus recipient uPA/RAG-2 mice revealed an enrichment of dysplastic precancerous hepatocytes in transplanted mice. Clonal amplification of hepatocytes from a woodchuck with hepatocellular carcinomas was demonstrated by the detection of unique WHV DNA integration patterns in hepatocellular carcinomas that arose in uPA/RAG-2 mice. In the absence of B or T cell-mediated immune responses, WHV establishes a persistent noncytotoxic infection of woodchuck hepatocytes in uPA/RAG-2 chimeric mouse livers. Further studies of the kinetics of hepadnavirus infection and replication in quiescent and proliferating hepatocytes should increase our understanding of hepadnavirus spread and aid in the design of therapies to block or cure persistent infection.     

Prognostic value of estimated glomerular filtration rate in hospitalized elderly patients

A multicenter observational study, REPOSI (REgistro POliterapie Società Italiana di Medicina Interna), was conducted to assess the prognostic value of glomerular filtration rate (eGFR) on in-hospital mortality, hospital re-admission and death within 3 months, in a sample of elderly patients (n = 1,363) admitted to 66 internal medicine and geriatric wards. Based on eGFR, calculated by the new Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) formula, subjects at hospital admission were classified into three groups: group 1 with normal eGFR (≥60 ml/min/1.73 m², reference group), group 2 with moderately reduced eGFR (30–59 ml/min/1.73 m²) and group 3 with severely reduced eGFR (<30 ml/min/1.73 m²). Patients with the lowest eGFR (group 3) on admission were more likely to be older, to have a greater cognitive and functional impairment and a high rate of comorbidities. Multivariable logistic regression analysis showed that severely reduced eGFR at the time of admission was associated with in-hospital mortality (OR 3.00; 95 % CI 1.20–7.39, p = 0.0230), but not with re-hospitalization (OR 0.97; 95 % CI 0.54–1.76, p = 0.9156) or mortality at 3 months after discharge (OR 1.93; 95 % CI 0.92–4.04, p = 0.1582). On the contrary, an increased risk (OR 2.60; 95 % CI 1.13–5.98, p = 0.0813) to die within 3 months after discharge was associated with decreased eGFR measured at the time of discharge. Our study demonstrates that severely reduced eGFRs in elderly patients admitted to hospital are strong predictors of the risk of dying during hospitalization, and that this measurement at the time of discharge helps to predict early death after hospitalization.     

Can ultrasound guidance reduce the risk of pneumothorax following thoracentesis?,

OBJECTIVE:

Thoracentesis is one of the bedside procedures most commonly associated with iatrogenic complications, particularly pneumothorax. Various risk factors for complications associated with thoracentesis have recently been identified, including an inexperienced operator; an inadequate or inexperienced support team; the lack of a standardized protocol; and the lack of ultrasound guidance. We sought to determine whether ultrasound-guided thoracentesis can reduce the risk of pneumothorax and improve outcomes (fewer procedures without fluid removal and greater volumes of fluid removed during the procedures). In our comparison of thoracentesis with and without ultrasound guidance, all procedures were performed by a team of expert pulmonologists, using the same standardized protocol in both conditions.

METHODS:

A total of 160 participants were randomly allocated to undergo thoracentesis with or without ultrasound guidance (n = 80 per group). The primary outcome was pneumothorax following thoracentesis. Secondary outcomes included the number of procedures without fluid removal and the volume of fluid drained during the procedure.

RESULTS:

Pneumothorax occurred in 1 of the 80 patients who underwent ultrasound-guided thoracentesis and in 10 of the 80 patients who underwent thoracentesis without ultrasound guidance, the difference being statistically significant (p = 0.009). Fluid was removed in 79 of the 80 procedures performed with ultrasound guidance and in 72 of the 80 procedures performed without it. The mean volume of fluid drained was larger during the former than during the latter (960 ± 500 mL vs. 770 ± 480 mL), the difference being statistically significant (p = 0.03).

CONCLUSIONS:

Ultrasound guidance increases the yield of thoracentesis and reduces the risk of post-procedure pneumothorax. (Chinese Clinical Trial Registry identifier: ChiCTR-TRC-12002174 [http://www.chictr.org/en/])     

An approach to iatrogenic deaths

Iatrogenic deaths are a concern for patients, physicians, and public health specialists. Most medicolegal investigation jurisdictions in the United States have the legal authority and mandate to investigate deaths associated with diagnostic/therapeutic procedures. Given the decreasing trends of autopsies performed in U.S. hospitals, forensic pathologists are likely to take on an even greater role in investigating these deaths. This is an overview and forensic pathological approach to fatal complications due to diagnostic and therapeutic medical events.