Laparoscopic hepatectomy for hepatocellular carcinoma in patients with clinically significant portal hypertension: a systematic review and meta-analysis

OBJECTIVE

To compare the effects of laparoscopic hepatectomy (LH) on the short-term and long-term outcomes in hepatocellular carcinoma (HCC) patients with and without clinically significant portal hypertension (CSPH).

METHODS

A systematic literature search of the PubMed, EMBASE, and Cochrane databases was performed for articles published from inception to March 1, 2023. Meta-analysis of surgical and oncological outcomes was performed using a random effects model. Data were summarized as mean difference and risk ratio with 95% confidence intervals.

RESULTS

Five cohort studies with a total of 310 HCC patients were included (CSPH 143; Non-CSPH 167). In terms of surgical outcomes, estimated blood loss and the length of hospital stay were significantly lower in the Non-CSPH group than in the CSPH group. There were no significant differences between the two groups regarding other surgical outcomes, including the operative time, ratio of conversion to open surgery, and overall complication rate. In addition, there were also no significant differences between the two groups regarding the oncological outcomes, such as 1-, 3-, and 5-year overall survival.

CONCLUSIONS

HCC patients with and without CSPH who underwent LH had comparable surgical and oncological outcomes. LH is a safe and effective treatment for HCC patients with CSPH under the premise of rational screening of patients.

Robotic versus laparoscopic liver resection for liver malignancy: a systematic review and meta-analysis of propensity score-matched studies

OBJECTIVE

How different surgical procedures, including the robotic-assisted liver resection (RLR) and laparoscopic liver resection (LLR), can affect the prognosis of patients with liver malignancies is unclear. Thus, in this study, we compared the effects of RLR and LLR on the surgical and oncological outcomes in patients with liver malignancies through propensity score-matched cohort studies.

METHODS

The PubMed, Embase, and Cochrane databases were searched using Medical Subject Headings terms and keywords from inception until May 31, 2023. The quality of the included studies was assessed using the Newcastle-Ottawa quality assessment scale. The mean difference with 95% confidence interval (95% CI) was used for analysis of continuous variables; the risk ratio with 95% CI was used for dichotomous variables; and the hazard ratio with 95% CI was used for survival-related variables. Meta-analysis was performed using a random-effects model.

RESULTS

Five high-quality cohort studies with 986 patients were included (370 and 616 cases for RLR and LLR, respectively). In terms of surgical outcomes, there were no significant differences in the operation time, conversion rate to open surgery, overall complication rate, major complication rate, and length of hospital stay between the RLR and LLR groups. In terms of oncological outcomes, there were no significant differences in the 5-year overall survival and disease-free survival between the two groups.

CONCLUSION

Surgical and oncological outcomes are comparable between RLR and LLR on patients with liver malignancies. Therefore, the benefits of applying RLR in patients with liver malignancies need to be further explored.

A visualized MAC nomogram online predicts the risk of three-month mortality in Chinese elderly aneurysmal subarachnoid hemorrhage patients undergoing endovascular coiling

OBJECTIVE

Aneurysmal subarachnoid hemorrhage (aSAH) is an aggressive disease with higher mortality rate in the elderly population. Unfortunately, the previous models for predicting clinical prognosis are still not accurate enough. Therefore, we aimed to construct and validate a visualized nomogram model to predict online the 3-month mortality in elderly aSAH patients undergoing endovascular coiling.

METHOD

We conducted a retrospective analysis of 209 elderly aSAH patients at People's Hospital of Hunan Province, China. A nomogram was developed based on multivariate logistic regression and forward stepwise regression analysis, then validated using the bootstrap validation method (n = 1000). In addition, the performance of the nomogram was evaluated by various indicators to prove its clinical value.

RESULT

Morbid pupillary reflex, age, and using a breathing machine were independent predictors of 3-month mortality. The AUC of the nomogram was 0.901 (95% CI: 0.853-0.950), and the Hosmer-Lemeshow goodness-of-fit test showed good calibration of the nomogram (p = 0.4328). Besides, the bootstrap validation method internally validated the nomogram with an area under the curve of the receiver operator characteristic (AUROC) of 0.896 (95% CI: 0.846-0.945). Decision curve analysis (DCA) and clinical impact curve (CIC) indicated the nomogram's excellent clinical utility and applicability.

CONCLUSION

An easily applied visualized nomogram model named MAC (morbid pupillary reflex-age-breathing machine) based on three accessible factors has been successfully developed. The MAC nomogram is an accurate and complementary tool to support individualized decision-making and emphasizes that patients with higher risk of mortality may require closer monitoring. Furthermore, a web-based online version of the risk calculator would greatly contribute to the spread of the model in this field.

Expression profiles of lncRNAs, miRNAs, and mRNAs during the proliferative phase of liver regeneration in mice with liver fibrosis

The role of lncRNAs in the regeneration of fibrotic liver is unclear. To address this issue, we established a 70% hepatectomy model of liver fibrosis in mice, used high-throughput sequencing technology to obtain the expression profiles of lncRNAs, miRNAs, and mRNAs, and constructed a lncRNA-miRNA-mRNA regulatory network. A total of 1329 lncRNAs, 167 miRNAs, and 6458 mRNAs were differentially expressed. On this basis, a lncRNA-miRNA-mRNA ceRNA regulatory network consisting of 38 DE lncRNAs, 24 DE miRNAs, and 299 DE mRNAs was constructed, and a transcription factor (TF) - mRNA regulatory network composed of 20 TFs and 98 DE mRNAs was built. Through the protein network analysis, a core protein interaction network composed of 20 hub genes was derived. Furthermore, Xist/miR-144-3p/Cdc14b and Snhg3/miR-365-3p/Map3k14 axes in the ceRNA regulatory network were verified by Real-Time quantitative PCR. Therefore, we concluded that these new insights may further our understanding of liver regeneration.

Laparoscopic versus open repeat hepatectomy for recurrent hepatocellular carcinoma: a systematic review and meta-analysis of propensity score-matched cohort studies

OBJECTIVE

The effectiveness of laparoscopic repeat hepatectomy (LRH) versus open repeat hepatectomy (ORH) on recurrent hepatocellular carcinoma (RHCC) is unclear. We compared the surgical and oncological outcomes of LRH and ORH in patients with RHCC with a meta-analysis of studies based on propensity score-matched cohorts.

METHODS

A literature search was conducted on PubMed, Embase, and Cochrane Library with Medical Subject Headings terms and keywords until 30 September 2022. The quality of eligible studies was evaluated with the Newcastle-Ottawa Scale. Mean difference (MD) with a 95% CI was used for the analysis of continuous variables; odds ratio (OR) with 95% CI was used for binary variables; and hazard ratio with 95% CI was used for survival analysis. A random-effects model was used for meta-analysis.

RESULTS

Five high-quality retrospective studies with 818 patients were included; 409 patients (50%) were treated with LRH and 409 (50%) with ORH. In most surgical outcomes, LRH was superior to ORH: less estimated blood loss, shorter operation time, lower major complication rate, and shorter length of hospital stay (MD=-225.9, 95% CI=[-360.8 to -91.06], P =0.001; MD=66.2, 95% CI=[5.28-127.1], P =0.03; OR=0.18, 95% CI=[0.05-0.57], P =0.004; MD=-6.22, 95% CI=[-9.78 to -2.67], P =0.0006). There were no significant differences in the remaining surgical outcomes: blood transfusion rate and overall complication rate. In oncological outcomes, LRH and ORH were not significantly different in 1-year, 3-year, and 5-year overall survival and disease-free survival.

CONCLUSIONS

For patients with RHCC, most surgical outcomes with LRH were superior to those of ORH, but oncological outcomes with the two operations were similar. LRH may be a preferable option for the treatment of RHCC.

Indole alkaloids fusarindoles A-E from marine-derived fungus Fusarium equiseti LJ-1

Five undescribed indole alkaloids, fusarindoles A-E, together with seven known compounds were obtained from the marine-derived fungus Fusarium equiseti LJ-1. Their chemical structures and absolute configurations were determined by comprehensive analysis of the NMR, HRMS, UV, IR, ECD calculation and single-crystal X-ray diffraction data. The possible biosynthetic pathways of fusarindoles C-E were proposed. The cytotoxicities of eleven compounds, including fusarindoles A-E and six known compounds, against five human cancer cell lines A549, CNE2, SUNE1, HepG2 and QGY7701 were evaluated.

Oncological outcomes of anatomic versus non-anatomic resections for small hepatocellular carcinoma: systematic review and meta-analysis of propensity-score matched studies

Background

Primary liver cancer is the second-most commonly occurring cancer and has resulted in numerous deaths worldwide. Hepatic resection is of two main types, i.e., anatomic resection (AR) and non-anatomic resection (NAR). The oncological outcomes of hepatocellular carcinoma (HCC) patients after AR and NAR are still considered controversial. Therefore, we aimed to compare the impact of AR and NAR on the oncological outcomes of HCC patients with tumor diameters ≤ 5 cm using the propensity score matching method and research-based evidence.

Method

A systematic literature search was conducted. The main outcomes were disease-free survival (DFS), overall survival (OS), intrahepatic recurrence rate, and extrahepatic metastasis rate. Relative risk (RR) was calculated from forest plots and outcomes using random-effects model (REM).

Result

AR significantly improved DFS at 1, 3. and 5 years after surgery, compared to NAR (RR = 1.09, 95% CI = 1.04–1.15, P = 0.0003; RR = 1.16, 95% CI = 1.07–1.27, P = 0.0005; RR = 1.29, 95% CI = 1.07–1.55, P = 0.008). However, both of the difference in DFS at 7 years and OS at 1 and 3 years after AR versus that after NAR were not statistically significant. Nevertheless, the long-term OS associated with AR (5, 7, and 10 years) was superior to that associated with NAR (RR = 1.12, 95% CI = 1.03–1.21, P = 0.01; RR = 1.19, 95% CI = 1.04–1.36, P = 0.01; RR = 1.18, 95% CI = 1.05–1.34, P = 0.008). The difference in the intrahepatic recurrence rate after AR versus that after NAR was not statistically significant, but the extrahepatic metastasis rate after AR was significantly lower than that observed after NAR (RR = 0.61, 95% CI = 0.40–0.94, P = 0.03).

Conclusion

Therefore, AR should be the preferred surgical approach for HCC patients with tumor diameters ≤ 5 cm.

Trial registration

PROSPERO registration number CRD42022330596.

Monascuslactams A-D, cytotoxic γ-lactams from marine fungus Monascus albidus BB3

Amino acid-directed strategy becomes an efficient way to explore the alkaloids' biosynthetic potential of marine fungi. The metabolites of marine fungus Monascus albidus BB3 were regulated obviously when cultured in GPY medium supplemented with L-tryptophan, L-phenylalanine, D,L-methionine, L-threonine, L-lysine, L-serine and L-valine. Four new γ-lactams, monascuslactams A-D (1-4), together with two known compounds pulchellalactam (5) and O-acetylperlolyrine (6) were obtained. Their structures were determined by comprehensive analysis on the 1 D and 2 D NMR, HRESIMS, UV and IR data, and their absolute configurations were assigned by the experimental and calculated ECD data analysis. Compounds 3, 4 and 6 showed moderate cytotoxicity against human cancer cell lines SUNE1, HepG2, QGY7701, GLC82, HCT116 and MDA-MB-231.

[Effect of adipose tissue-derived mesenchymal stem cell transplantation in treatment of liver fibrosis and possible mechanism]

Objective: To investigate the effect of adipose tissue-derived mesenchymal stem cell (ADSC) transplantation in the treatment of liver fibrosis rats and possible mechanism. Methods: Subcutaneous adipose tissue in the inguinal region of rats was collected to isolate ADSCs. The rats with liver fibrosis induced by intraperitoneally injected carbon tetrachloride were divided into cell transplantation group and phosphate buffer saline (PBS) injection group, and the rats which were fed normally were enrolled as negative control group. The rats in the cell transplantation group were given tail vein injection of ADSCs, and those in the PBS injection group were given injection of 0.5 ml PBS. At 7 days after transplantation, blood samples were collected from the inferior vena cava to evaluate liver function; liver tissue was collected to measure the protein expression of hepatocyte growth factor (HGF) and alpha-smooth muscle actin (α-SMA); Masson trichrome staining was used to evaluate intrahepatic collagen deposition. Hepatic stellate cells (HSCs) were collected from the rats with liver fibrosis, and indirect co-culture of HSCs and ADSCs was performed in vitro to analyze the influence of ADSCs on the proliferation and apoptosis of HSCs. The independent samples t-test was used for comparison between groups, and an analysis of variance was used for comparison of means between multiple samples. Results: ADSCs were found in liver tissue in the transplantation group, and compared with the PBS injection group, the transplantation group had significant alleviation in hepatocyte necrosis, vacuolization, and area of fibrosis and significant reductions in the serum levels of aminotransferases, while there was no significant difference in the level of albumin between the two groups. Compared with the PBS injection group, the transplantation group had significant upregulation in the protein expression of HGF and significant downregulation in the protein expression of α-SMA (both P < 0.05). In vitro co-culture for 72 hours showed that ADSCs inhibited the proliferation of HSCs, and there was a significant difference between the co-culture group and the control group with HSCs cultured alone. Caspase-3 immunostaining showed that after co-culture for 72 hours, there was a significant difference in the apoptosis rate of HSCs between the co-culture group and the control group with HSCs cultured alone (23.42% ± 3.02% vs 14.82% ± 3.93%). Conclusion: ADSC transplantation can upregulate the expression of HGF in the liver, promote the apoptosis of HSCs, and thus alleviate liver fibrosis.

[A comparative study of diagnostic efficacy of different diagnostic/ classification criteria in Takayasu arteritis]

OBJECTIVE

This study aimed to analyze and evaluate the diagnostic efficacy of Ishikawa's, the modified Ishikawa's criteria, 1990 American College of Rheumatology (ACR ) classification criteria and the diagnostic model based on Chinese population in Chinese TA patients.

METHODS

One hundred and forty-nine patients with Takayasu arteritis and 126 patients with other vascular disorders which involved aorta or its branches were recruited in this study.All the patients were admitted to the Department of rheumatism and Immunology clinic or inpatient department of Zhongshan Hospital affiliated to Fudan University from January 1(st), 2008 to June 31(st), 2015.General characteristics, clinical manifestations, laboratory results and imaging data of all the patients were collected.Sensitivity, specificity, accuracy and area under receiver operating characteristics (ROC) curve of different criteria were analyzed.

RESULTS

Sensitivity, specificity, accuracy and area under ROC curve of Chinese diagnostic model were 90.60%, 80.95%, 86.18%, and 85.80%, respectively, while those of Ishikawa criteria were 34.23%, 99.21%, 64.00%, and 66.70%, respectively.These four indicators of the modified Ishikawa criteria were 84.13%, 79.87%, 81.82%, and 82.00%, respectively and that of ACR criteria were 83.89%, 83.33%, 83.64%, and 83.60%, respectively.No significant difference was found between any two of Chinese diagnostic model, the modified Ishikawa criteria and ACR criteria in all the indicators.Sensitivity of Chinese diagnostic model was highest, while specificity of Ishikawa criteria was the highest.Among these four criteria, the diagnostic efficacy of Chinese model was the best and that of Ishikawa criteria was the worst.

CONCLUSION

Chinese diagnostic model, which is based on Chinese population and adopts advanced imaging modality, has better diagnostic efficacy.

Treatment of postparotidectomy Frey syndrome with the interposition of temporalis fascia and sternocleidomastoid flaps

OBJECTIVES

This study was performed to evaluate the effectiveness of overlapping the temporalis fascia flaps (TFFs) and the sternocleidomastoid muscle flaps (SCMFs) as physical barriers to treat established Frey syndrome and concavity after parotidectomy.

STUDY DESIGN

We retrospectively reviewed 17 patients who underwent corrective procedures with simultaneous TFF and SCMF interposition for the treatment of Frey syndrome. The affected areas of the cheek skin were identified with starch-iodine tests. The facial contours of the patients were classified as bilaterally symmetric (BS), with a slightly shallow (SS) contour on the surgical side, or with a conspicuously shallow (CS) contour on the surgical side.

RESULTS

The sample was followed up for a mean of 22 months. The average area of gustatory-sweating positive skin was reduced from 12.80 to 1.32 square centimeters postoperatively. The facial asymmetry secondary to parotidectomy was greatly improved.

CONCLUSIONS

The authors concluded that this technique was efficacious in ameliorating Frey syndrome and facial concavity secondary to parotidectomy.

Dopamine receptor DR2 expression in B cells is negatively correlated with disease activity in rheumatoid arthritis patients

OBJECTIVE

Dopamine receptor (DR) signaling is involved in the pathogenesis of autoimmune diseases. We aimed to measure the expression levels of DR1-5 on B cells from patients with rheumatoid arthritis (RA) and to analyze the relationship between DRs and clinical manifestations, inflammatory biomarkers, functional status and disease activity.

METHODS

A total of 29 patients with RA, 12 healthy donors and 12 patients with osteoarthritis (OA) were recruited in this study. Flow cytometry was used to measure the levels of DR1-5 expressed on B cells. The relationships between B cell DR expressions and clinical features in RA patients were analyzed using the Spearman correlation test.

RESULTS

The expression levels of B cell DR1-5 in both the RA and OA groups were lower than those in healthy controls. After 3 months of medication, all five receptors were elevated in RA patients, with DR2 and DR3 being significantly increased from the baseline. DR2 expression on B cells was negatively correlated with inflammatory biomarkers and disease activity.

CONCLUSION

RA patients had lower expression level of DR2 on B cells compared to the healthy controls, and the level of DR2 negatively correlated with the disease activity. DR2 and DR3 might be novel predictors of patient responses to disease modifying antirheumatic drug therapy.

Association of ELMO1 gene polymorphisms with diabetic nephropathy in Chinese population

BACKGROUND

Genetic variations in the engulfment and cell motility 1 (ELMO1) gene have recently been identified to be associated with nephropathy attributed to Type 2 diabetes mellitus (T2DM). Since T2DM-associated complications are proved to be more common among Asians than Western individuals, and Chinese people have a high incidence of diabetic nephropathy (DN), this study sought to analyze the association of ELMO1 gene polymorphisms with DN to probe into the effects of ELMO1 gene on susceptibility of DN in Chinese population.

METHODS

We genotyped 6 polymorphism sites of ELMO1 gene in 200 unrelated Chinese subjects (123 T2DM with DN case subjects and 77 T2DM without DN control subjects). Genotyping was detected by a Sequenom MassARRAY genotyping system.

RESULTS

The strongest associations in ELMO1 gene with DN occurred at rs741301 [odds ratio (OR) 1.89; p=0.004] and rs10951509 (OR 1.76; p=0.02). Unconditional logistic regression analysis identified that the rs741301 polymorphism (presence of A allele, adjusted OR 3.27; p=0.03) and duration of T2DM (adjusted OR 1.15; p=0.04) were independent predictors for DN. The marker rs741301 located in intron 18 of ELMO1 gene was in strong linkage disequilibrium (LD) with rs11769038 (D'=0.91). Furthermore, haplotype analysis identified that haplotype 1 [CAAAGA] (OR 1.95; p=0.01), haplotype 2 [CAAAGG] (OR 0.50; p=0.01), and haplotype 9 [TGCGGG] (OR 0.17; p=0.007) of ELMO1 were significantly associated with DN.

CONCLUSIONS

This study first investigated the association of ELMO1 gene polymorphisms with DN in a Chinese population, supporting its key role as a candidate gene in the susceptibility of DN.

[Analyze on the component of rosmarinic acid in Prunella vulgaris and its effect on alpha-glycosidase activity]

OBJECTIVE

To analyze rosmarinic acid in Prunella vulgaris and its effect on the activity of alpha-glycosidase.

METHODS

Qualitative and quantitative analyses of Rosmarinic acid in Prunella vulgaris were carried out by HPLC. The activity of different micro reaction systems like alpha-amylase, alpha-glucosidase and alpha-maltase, which were added to Rosmarinic acid and Acarbose, was determined by Bernfeld, pNPG and GOD.

RESULTS

The contents of Rosmarinic acid in the aqueous extract and its dry powder, and extractum of Prunella vulgaris were 0.1494, 0.1657 and 0.2739 mg/g respectively, equal to crude drug. The Rosmarinic acid inhibited alpha-glycosidase, and its inhibition from alpha-maltase in small intestine was noncompetitive.

CONCLUSION

The aqueous extract of Prunella vulgaris and its extractum's inhibition from alpha-glycosidase is related to Rosmarinic acid.

An exploration of the extended lymph node dissection and skeletonization of the vasculature for pancreatic adenocarcinoma

About 50%-90% of patients with pancreas carcinoma are found to have metastatic tumors when diagnosis is confirmed. The metastasis routes include via circulation system, lymph-node, and invasion to solar nerve plexus which usually occurs in 70% of patients. Pancreatoduodenectomy (PD) is the routine operation performed for pancreas carcinoma. There is also operation plan suggesting the resection of the nerve plexus and soft tissue distributing along the artery vessels, and the nerve fiber bat around the pancreas. This operation is also named as skeletonization of the vasculature. There have been different point-views from different surgery groups, on whether the extended lymphadenectomy (ELND) can extend the survival length and improve life quality of patients or not. However, ELND is considered to be possible to prolong the survival time for the patients with positive nodal metastasis.

[Expression of human interleukin-1 receptor antagonist in the transfected chondrocytes of temporomandibular joint]

OBJECTIVE

To investigate the expression of the human interleukin-1 receptor antagonist (hIL-1ra) in the transfected chondrocytes of temporomandibular joint (TMJ).

METHODS

Chondrocytes of TMJ in vitro were transfected by hIL-1ra gene via cationic liposome as a medium. The stable transfected cells were selected by G418. The proliferations of the transduced cell were examined with the growth curve, cell population doubling time. The protein expressing in different periods was detected by immunocytochemistry and enzyme-linked immunosorbent assay (ELISA).

RESULTS

The proliferation suppression of gene transfected cells fell significantly with compared to normal cells. The expression of hIL-1ra was detected in the cell plasma and the cell culture supernatant. The highest expression of IL-1ra protein was at the time of 48 hours after gene transfection. The transiently transfected cells were secreted IL-1ra protein continuously 28 days and the stably transduced cells were secreted IL-1ra protein till 72 days.

CONCLUSION

This study showed that hIL-1ra protein expressed positively in the cell plasma and the culture supernatant after gene transfection within a certain periods.

Rescue of the colony-stimulating factor 1 (CSF-1)-nullizygous mouse (Csf1(op)/Csf1(op)) phenotype with a CSF-1 transgene and identification of sites of local CSF-1 synthesis

Colony-stimulating factor 1 (CSF-1) regulates the survival, proliferation, and differentiation of mononuclear phagocytes. It is expressed as a secreted glycoprotein or proteoglycan found in the circulation or as a biologically active cell-surface glycoprotein. To investigate tissue CSF-1 regulation, CSF-1-null Csf1(op)/Csf1(op) mice expressing transgenes encoding the full-length membrane-spanning CSF-1 precursor driven by 3.13 kilobases of the mouse CSF-1 promoter and first intron were characterized. Transgene expression corrected the gross osteopetrotic, neurologic, weight, tooth, and reproductive defects of Csf1(op)/Csf1(op) mice. Detailed analysis of one transgenic line revealed that circulating CSF-1, tissue macrophage numbers, hematopoietic tissue cellularity, and hematopoietic parameters were normalized. Tissue CSF-1 levels were normal except for elevations in 4 secretory tissues. Skin fibroblasts from the transgenic mice secreted normal amounts of CSF-1 but also expressed some cell-surface CSF-1. Also, lacZ driven by the same promoter/first intron revealed beta-galactosidase expression in hematopoietic, reproductive, and other tissue locations proximal to CSF-1 cellular targets, consistent with local regulation by CSF-1 at these sites. These studies indicate that the 3.13-kilobase promoter/first intron confers essentially normal CSF-1 expression. They also pinpoint new cellular sites of CSF-1 expression, including ovarian granulosa cells, mammary ductal epithelium, testicular Leydig cells, serous acinar cells of salivary gland, Paneth cells of the small intestine, as well as local sites in several other tissues.

Natural isolates of simian virus 40 from immunocompromised monkeys display extensive genetic heterogeneity: new implications for polyomavirus disease

Simian virus 40 (SV40) DNAs in brain tissue and peripheral blood mononuclear cells (PBMCs) of eight simian immunodeficiency virus-infected rhesus monkeys with SV40 brain disease were analyzed. We report the detection, cloning, and identification of five new SV40 strains following a quadruple testing-verification strategy. SV40 genomes with archetypal regulatory regions (containing a duplication within the G/C-rich regulatory region segment and a single 72-bp enhancer element) were recovered from seven animal brains, two tissues of which also contained viral genomes with nonarchetypal regulatory regions (containing a duplication within the G/C-rich regulatory region segment as well as a variable duplication within the enhancer region). In contrast, PBMC DNAs from five of six animals had viral genomes with both regulatory region types. It appeared, based on T-antigen variable-region sequences, that nonarchetypal virus variants arose de novo within each animal. The eighth animal exclusively yielded a new type of SV40 strain (SV40-K661), containing a protoarchetypal regulatory region (lacking a duplication within the G/C-rich segment of the regulatory region and containing one 72-bp element in the enhancer region), from both brain tissue and PBMCs. The presence of SV40 in PBMCs suggests that hematogenous spread of viral infection may occur. An archetypal version of a virus similar to SV40 reference strain 776 (a kidney isolate) was recovered from one brain, substantiating the idea that SV40 is neurotropic as well as kidney-tropic. Indirect evidence suggests that maternal-infant transmission of SV40 may have occurred in one animal. These findings provide new insights for human polyomavirus disease.

Partial characterization of the genome of nine animal caliciviruses

Caliciviruses (CVs) include at least 42 distinct serotypes. Seventeen CV serotypes have been isolated from marine sources and are called San Miguel sea lion caliciviruses (SMSVs). CVs also have been isolated from reptiles, primates, and other terrestrial animals. Nucleotide sequences from portions of genome of prototype strains for six SMSV serotypes, the reptile CV, Cro-1, the cetacean CV, Tur-1, and the primate CV, Pan-1, are presented. cDNA products of the polymerase (all strains characterized) and capsid (SMSV-17) regions were produced by reverse transcription-polymerase chain reaction using Pan-1 primers. Comparisons of nucleotide and amino acid identity among these and published CV sequences indicated that the nine characterized CVs fall into a phylogenetic group that includes SMSV-1 and SMSV-4 and that is more closely related to other characterized animal CVs than to most human CVs. The phylogenetic analysis also indicated that distinct genera exist among the Caliciviridae. SMSV-17 and SMSV-4 are predicted to be closer to each other than other caliciviruses of known serotype; 574 (82%) of the 704 amino acids in the SMSV-17 and SMSV-4 capsid genes were identical.

Outbreaks of gastroenteritis in elderly nursing homes and retirement facilities associated with human caliciviruses

Eleven outbreaks of acute gastroenteritis, eight of which were in nursing homes or retirement facilities, were reported in virginia during the winter of 1993-1994. Serum samples (four outbreaks) and stool samples (two outbreaks) from involved people were tested for human calicivirus (HuCV) infection by enzyme immune assays (EIAs) using recombinant Norwalk virus (rNV) and Mexico virus (rMX) capsid antigens and reverse transcription-polymerase chain reaction (RT-PCR). Of the 31 pairs of acute and convalescent serum specimens tested, 24 had a fourfold or more titer increase to rMX and 4 responded to rNV. In all four outbreaks, the geometric mean titers (GMTs) against rMX were significantly higher than those against rNV in the convalescent, but not in the acute phase of illness. The antibody response to rMX among these patients was also higher than to rNV (summary mean 32-fold increase vs. 0.7-fold increase, respectively, P < .001). Antigen was detected in 5 of 21 stool specimens tested by the rMX EIA, RNA in 12 of 17 stool specimens tested by RT-PCR, and small round structured virus (SRSV) particles in 12 of 21 by electron microscopy (EM); none were positive by the rNV EIA. Sequence analysis of the RT-PCR-amplified products from the viral RNA polymerase region revealed 92-93% amino acid identity with Snow Mountain agent (SMA), 86% with MX, 58-59% with NV, and 31-32% with Sapporo HuCV, suggesting that these viruses belong to the SMA HuCV genogroup.