Effect of the SARS-CoV-2 pandemic on colorectal cancer diagnosis and prognosis

BACKGROUND AND STUDY AIMS

Our aim was to determine the impact of the SARS-CoV-2 pandemic on the diagnosis and prognosis of colorectal cancer (CRC).

PATIENTS AND METHODS

This prospective cohort study included individuals diagnosed with CRC between March 13, 2019 and June 20, 2021 across 21 Spanish hospitals. Two time periods were compared: prepandemic (from March 13, 2019 to March 13, 2020) and pandemic (from March 14, 2020 to June 20, 2021, lockdown period and 1 year after lockdown).

RESULTS

We observed a 46.9% decrease in the number of CRC diagnoses (95% confidence interval (CI): 45.1%-48.7%) during the lockdown and 29.7% decrease (95% CI: 28.1%-31.4%) in the year after the lockdown. The proportion of patients diagnosed at stage I significantly decreased during the pandemic (21.7% vs. 19.0%; p = 0.025). Centers that applied universal preprocedure SARS-CoV-2 PCR testing experienced a higher reduction in the number of colonoscopies performed during the pandemic post-lockdown (34.0% reduction; 95% CI: 33.6%-34.4% vs. 13.7; 95% CI: 13.4%-13.9%) and in the number of CRCs diagnosed (34.1% reduction; 95% CI: 31.4%-36.8% vs. 26.7%; 95% CI: 24.6%-28.8%). Curative treatment was received by 87.5% of patients diagnosed with rectal cancer prepandemic and 80.7% of patients during the pandemic post-lockdown period (p = 0.002).

CONCLUSIONS

The COVID-19 pandemic has led to a decrease in the number of diagnosed CRC cases and in the proportion of stage I CRC. The reduction in the number of colonoscopies and CRC diagnoses was higher in centers that applied universal SARS-CoV-2 PCR screening before colonoscopy. In addition, the COVID-19 pandemic has affected curative treatment of rectal cancers.

The Fungal Endophyte Penicillium olsonii ML37 Reduces Fusarium Head Blight by Local Induced Resistance in Wheat Spikes

The fungal endophyte Penicillium olsonii ML37 is a biocontrol agent of Fusarium head blight in wheat (caused by Fusarium graminearum), which has shown a limited direct inhibition of fungal growth in vitro. We used RNA-seq and LC-MS/MS analyses to elucidate metabolic interactions of the three-way system Penicillium–wheat–Fusarium in greenhouse experiments. We demonstrated that P. olsonii ML37 colonises wheat spikes and transiently activates plant defence mechanisms, as pretreated spikes show a faster and stronger expression of the defence metabolism during the first 24 h after pathogen inoculation. This effect was transient and the expression of the same genes was lower in the pathogen-infected spikes than in those infected by P. olsonii alone. This response to the endophyte includes the transcriptional activation of several WRKY transcription factors. This early activation is associated with a reduction in FHB symptoms and significantly lower levels of the F. graminearum metabolites 15-acetyl-DON and culmorin. An increase in the Penicillium-associated metabolite asperphanamate confirms colonisation by the endophyte. Our results suggest that the mode of action used by P. olsonii ML37 is via a local defence activation in wheat spikes, and that this fungus has potential as a novel biological alternative in wheat disease control.

Straw Competition and Wheat Root Endophytism of Trichoderma gamsii T6085 as Useful Traits in the Biological Control of Fusarium Head Blight

Trichoderma gamsii T6085 has been investigated for many years as a beneficial isolate for use in the biocontrol of Fusarium head blight (FHB) of wheat caused primarily by Fusarium graminearum. Previous work focused on application of T6085 to wheat spikes at anthesis, whereas application to soil before or at sowing has received limited attention. In the present study, the competitive ability of T6085 on plant residues against F. graminearum was investigated. Results showed a significant reduction of wheat straw colonization by the pathogen and of the development of perithecia, not only when T6085 was applied alone but also in the presence of a F. oxysporum isolate (7121), well known as a natural competitor on wheat plant residues. T6085 was able to endophytically colonize wheat roots, resulting in internal colonization of the radical cortex area, without reaching the vascular system, as confirmed by confocal microscopy. This intimate interaction with the plant resulted in a significant increase of the expression of the plant defense-related genes PAL1 and PR1. Taken together, competitive ability, endophytic behavior, and host resistance induction represent three important traits that can be of great use in the application of T6085 against FHB not only on spikes at anthesis but potentially also in soil before or at sowing.

The effect of management models on thromboembolic and bleeding rates in anticoagulated patients: an ecological study

The primary study objective is to compare the outcomes of patients taking oral anticoagulant medications in two distinct populations treated according to different management models (comprehensive vs. usual care). (Design: regional prospective cohort study; setting: hospital admission data from two regions). Eligible partecipants were patients taking oral anticoagulant drugs (vitamin K antagonist or direct oral anticoagulants), residents in the Vicenza and Cremona districts from February 1st, 2016 to June 30th, 2017. Patients were identified by accessing the administrative databases of patient drug prescriptions. The primary study outcome was admission to the Emergency Department for stroke, systemic arterial embolism, recurrence of venous thromboembolism or major bleeding. The study evaluated outcomes in 14,226 patients taking oral anticoagulants, of whom 6725 being followed in Cremona with a comprehensive management model. There were 19 and 45 thromboembolic events over 6205 and 6530 patient-years in the Cremona and Vicenza cohort, respectively (IRR 0.44, 95% CI 0.24-0.77). The reduction of events in the Cremona cohort was almost entirely explained by a decrease of events in patients taking VKA (IRR 0.41, 95% CI 0.20-0.78) but not DOACs (IRR 1.08, 95% CI 0.25-5.24). The rate of major bleeding was non-significantly higher in Cremona than in Vicenza (IRI 1.32; 95% CI 0.74-2.40). Across the two cohorts, the risk of bleeding was lower in patients being treated with DOACs rather than warfarin (10/4574 vs. 42/8161 event/person-years, respectively, IRR 0.42 95% CI 0.19-0.86). We conclude that a comprehensive management model providing centralized dose prescription and follow-up may significantly reduce the rate of thromboembolic complications, without substantially increasing the number of bleeding complications. Patients treated with direct oral anticoagulants appear to have a rate of thromboembolic complications comparable to VKA patients under the best management model, with a reduction of major bleeding.

Is Exploitation Competition Involved in a Multitrophic Strategy for the Biocontrol of Fusarium Head Blight?

Trichoderma gamsii T6085 was used in combination with a Fusarium oxysporum isolate (7121) in order to evaluate, in a multitrophic approach, their competitive ability against F. graminearum, one of the main causal agents of Fusarium head blight (FHB) on wheat. The two antagonists and the pathogen were coinoculated on two different natural substrates, wheat and rice kernels. Both T6085 and 7121, alone and coinoculated, significantly reduced the substrate colonization and mycotoxin production by the pathogen. The two antagonists did not affect each other. Using a metabolic approach (Biolog), we investigated whether exploitation competition could explain this antagonistic activity. The aim was to define whether the three fungi coexist or if one isolate nutritionally dominates another. Results obtained from Biolog suggest that no exploitative competition occurs between the antagonists and the pathogen during the colonization of the natural substrates. Interference competition was then preliminarily evaluated to justify the reduction in the pathogen's growth and to better explain mechanisms. A significant reduction of F. graminearum growth was observed when the pathogen grew in the cultural filtrates of T. gamsii T6085, both alone and cocultured with F. oxysporum 7121, thus suggesting the involvement of secondary metabolites. As far as we know, this is the first time that an ecological study has been performed to explain how and which kind of competition could be involved in a multitrophic biocontrol of FHB.

High incidence of advanced colorectal neoplasia during endoscopic surveillance in serrated polyposis syndrome

BACKGROUND

Serrated polyposis syndrome (SPS) has been associated with an increased risk of colorectal cancer (CRC). Accordingly, intensive surveillance with annual colonoscopy is advised. The aim of this multicenter study was to describe the risk of advanced lesions in SPS patients undergoing surveillance, and to identify risk factors that could guide the prevention strategy.

METHODS

From March 2013 to April 2015, 296 patients who fulfilled criteria I and/or III for SPS were retrospectively recruited at 18 centers. We selected patients in whom successful clearing colonoscopy had been performed and who underwent subsequent endoscopic surveillance. Advanced neoplasia was defined as CRC, advanced adenoma, or advanced serrated lesion that were ≥ 10 mm and/or with dysplasia. Cumulative incidence of advanced neoplasia was calculated and independent predictors of advanced neoplasia development were identified.

RESULTS

In 152 SPS patients a total of 315 surveillance colonoscopies were performed (median 2, range 1 - 7). The 3-year cumulative incidence of CRC and advanced neoplasia were 3.1 % (95 % confidence interval [CI] 0 - 6.9) and 42.0 % (95 %CI 32.4 - 51.7), respectively. Fulfilling both I + III criteria and the presence of advanced serrated lesions at baseline colonoscopy were independent predictors of advanced neoplasia development (odds ratio [OR] 1.85, 95 %CI 1.03 - 3.33, P  = 0.04 and OR 2.62, 95 %CI 1.18 - 5.81, P  = 0.02, respectively). During follow-up, nine patients (5.9 %) were referred for surgery for invasive CRC (n = 4, 2.6 %) or because of polyp burden (n = 5, 3.3 %). After total colectomy, 17.9 % patients developed advanced neoplasia in the retained rectum.

CONCLUSIONS

Patients with SPS have a substantial risk of developing advanced neoplasia under endoscopic surveillance, whereas CRC incidence is low. Personalized endoscopic surveillance based on polyp burden and advanced serrated histology could help to optimize prevention in patients with SPS.

Evidences supporting the vascular etiology of post-double balloon enteroscopy pancreatitis: Study in porcine model

Double balloon enteroscopy (DBE) is an endoscopic technique broadly used to diagnose and treat small bowel diseases. Among the associated complications of the oral DBE, post-procedure pancreatitis has taken the most attention due to its gravity and the thought that it might be associated to the technique itself and anatomical features of the pancreas. However, as the etiology has not been clarified yet, this paper aims to review the published literature and adds new results from a porcine animal model. Biochemical markers, histological sections and the vascular perfusion of the pancreas were monitored in the pig during DBE practice. A reduced perfusion of the pancreas and bowel, the presence of defined hypoxic areas and disseminated necrotic zones were found in the pancreatic tissue of pigs. All these evidences contribute to support a vascular distress as the most likely etiology of the post-DBE pancreatitis.

Colorectal cancer risk factors in patients with serrated polyposis syndrome: a large multicentre study

OBJECTIVE

Serrated polyposis syndrome (SPS) is associated with an increased colorectal cancer (CRC) risk, although the magnitude of the risk remains uncertain. Whereas intensive endoscopic surveillance for CRC prevention is advised, predictors that identify patients who have high CRC risk remain unknown. We performed a multicentre nationwide study aimed at describing the CRC risk in patients with SPS and identifying clinicopathological predictors independently associated with CRC.

DESIGN

From March 2013 through September 2014, patients with SPS were retrospectively recruited at 18 Spanish centres. Data were collected from medical, endoscopy and histopathology reports. Multivariate logistic regression was performed to identify CRC risk factors.

RESULTS

In 296 patients with SPS with a median follow-up time of 45 months (IQR 26-79.7), a median of 26 (IQR 18.2-40.7) serrated polyps and 3 (IQR 1-6) adenomas per patient were detected. Forty-seven patients (15.8%) developed CRC at a mean age of 53.9±12.8, and 4 out of 47 (8.5%) tumours were detected during surveillance (cumulative CRC incidence 1.9%). Patients with >2 sessile serrated adenomas/polyps (SSA/Ps) proximal to splenic flexure and ≥1 proximal SSA/P with high-grade dysplasia were independent CRC risk factors (incremental OR=2, 95% CI 1.22 to 3.24, p=0.006). Patients with no risk factors showed a 55% decrease in CRC risk (OR=0.45, 95% CI 0.24 to 0.86, p=0.01).

CONCLUSIONS

Patients with SPS have an increased risk of CRC, although lower than previously published. Close colonoscopy surveillance in experienced centres show a low risk of developing CRC (1.9% in 5 years). Specific polyp features (SSA/P histology, proximal location and presence of high-grade dysplasia) should be used to guide clinical management.

Effect of 6 weeks of whole body vibration training on total and segmental body composition in healthy young adults

The applied use of new technologies to enhance performance and improve health has been increasing. Initially, whole body vibration training (WBVT) was used as system to improve elite athlete performance. However, this is also used to improve body composition, especially there is a great attention on the effectiveness of WBVT to reduce fat and body weight, with a potential increase in muscle tissue. The aim of this study was to investigate the effects of a 6-week vibration-training program on total and segmental body composition in a group of physically healthy participants. The final study sample included 64 healthy young adults. Subjects were randomly allocated into the control group (CG: n = 26; 16 males and 10 females) and the experimental group (EGWBVT: n = 38; 19 males and 19 females). The program lasted six weeks with a frequency of three sessions per week and each session varied in intensity. There were not found statistically significant differences in any of the body composition variables analysed. This study suggests that a six-week vibration-training program with an increasing intensity (7.2 g-32.6 g) in healthy young adults that are not overweight did not alter total and segmental body composition.

Ischemic etiopathogenesis as the possible origin of post-double baloon enteroscopy pancreatitis. A porcine model study

The aim is to evaluate the pancreatic vascular-ischemic effects related to double balloon enteroscopy in the porcine model as a possible etiopathogenesis of post-enteroscopic pancreatitis. For this reason we carry out two independent experiments in a porcine animal model. In the first arm protocol (group I), 10 animals underwent 90 minutes of oral enteroscopy with 7 days follow-up.The levels of amylase, lipase and C-reactive protein were measured at T0 basal-T1 -90 min, T2-24, T3-7 days. Also we perform upper gastrointestinal endoscopy in a control group. At 7 days, the animals of experimental protocol-I had their pancreases removed for a pathological and immunohistochemical study to evaluate vascular epithelial growth factor (VEGF) expression.The second experimental protocol in this study aims to evaluate possible changes in vascular topography due to the double balloon enteroscopy (DBE). Group-II (10 animals) underwent oral enteroscopy and selective angiography of the cranial mesenteric artery and celiac trunk. None of the group I or control group animals presented pancreatitis, although the biochemical results for group-I showed increases in the levels of amylase, lipase and C reactive protein at 24 hours. The microscopic study for group-I showed pancreatic necrotic foci and positive VEGF expression, though these changes were not expressed in the control group.These foci were found in 50% of the group I animals and in relation to the total of the parenchyma were quantified at 6% of the pancreas. The results for group-II showed that the enteroscopy caused mobilization of the mesenteric vascular axis, with signs of both intestinal and pancreatic hypoperfusion. The conclusions of this study are that, after enteroscopy in the porcine model, pancreatic necrotic foci are produced, in addition to ischemic phenomena causing VEGF expression. This could be related to episodes of visceral hypoperfusion caused by vascular alterations on a topographic level. This can be related to the possible ischemic etiopathogenesis described for post-enteroscopic pancreatitis.

Carbon dioxide insufflation safety in double-balloon enteroscopy: an experimental animal study

AIM

The aim of the present study was to assess the safety and efficacy of CO(2) during double-balloon enteroscopy (DBE) in an experimental animal model study. In this study, insufflation with room air and with CO(2) was compared.

METHODS

Twenty healthy swines were used. The animals were randomly allocated to two groups. The room air-DBE group was insufflated with room air, whereas the CO(2)-DBE group was insufflated with CO(2). Endoscopy duration was 90 min. The following parameters were measured during the study (basal, 30 min, 60 min, 90 min): invasive hemodynamic parameters, ventilatory parameters, arterial blood gases, exploration depth, as well as biochemical tests. Residual gas was evaluated at the end of DBE, at 180 min and 24 h after DBE.

RESULTS

During the endoscopic exploration none of the animals showed hemodynamic, ventilatory or arterial blood gas alterations in the normal reference range for the swine species. The CO(2) group showed statistically significant differences over the room air group with lower post-procedure residual gas and greater depth of the small bowel explored.

CONCLUSION

The use of CO(2) for insufflation during DBE was safe and no complications associated with CO(2) were observed. In addition, the use of CO(2) offers benefits over the use of room air for insufflation during DBE.

Effect of double-balloon enteroscopy on pancreas: an experimental porcine model

AIM

To evaluate the effect of double-balloon enteroscopy (DBE) on pancreas histology and levels of pancreatic enzymes.

METHODS

Conventional upper gastrointestinal endoscopy was performed on five control pigs. Oral DBE was performed with an EN-450T5 enteroscope on 20 pigs. Two experimental groups (10 pigs each) were defined according to DBE duration: 90 min for Group 1 and 140 min for group 2. During oral insertion, the balloons were not inflated in the descending part of the duodenum to avoid the minor duodenal papilla. Serum amylase, lipase and C-reactive protein (CRP) levels were monitored before the procedure and repeated every 30 min until the exploration was finished, as well as 24 h and 7 d after. After the procedure and for a total of 7 d, the pigs were observed twice a day for signs of decreased activity, irritability, vomiting or anorexia. Gross and microscopic examination of the pancreas was performed on day 7.

RESULTS

All animals tolerated DBE without clinical manifestations of acute pancreatitis. Experimental groups had higher levels of enzymes than the control group at 24 h. Throughout the exploration, the amylase levels increased significantly above the baseline 24 h after DBE, although the increase was not statistically significant and did not reach 20% of the baseline. An increase in lipase and CRP was observed at 24 h after the procedure, although by day 7, all enzymatic levels had returned to baseline. No differences between groups 1 and 2 were found for any enzyme and sampling site during and after the procedure. Similarly, no correlation between insertion depth and enzyme levels was observed. Direct in situ and post-removal inspection of the pancreas did not show any evidence of fluid collection, abscesses or hemorrhage. Histological examination of the pancreas from groups 1 and 2 revealed the existence of focal areas (0.14-0.26 mm2) of ischemic necrosis in 47.4% of the animals. In the pigs with damaged pancreas, the left lobe (tail) was always affected. However, this only happened in 83.3% of the samples from the right lobe (head) and in 33.3% of the samples from the body of the pancreas. Significant differences were found between the left lobe (tail) and the body for the percentage of affected pancreas. Both the size of the lesions and the percentage of affected pancreas were higher in the left pancreatic lobe (tail). The presence of the lesions was not related to the exploration length.

CONCLUSION

The increase in pancreatic enzymes after DBE could be related to focal points of pancreatic ischemic necrosis due to mechanical stress.

Characterization of oral double balloon endoscopy in the dog

Exploration of the canine small intestine using conventional endoscopy is restricted to the duodenum and/or the ileum. Double balloon endoscopy (DBE) is a 'push and pull' technique that has been described in humans and permits a complete exploration of the small intestine. In this study, oral DBE was performed on 12 healthy dogs (10-34kg) to characterize for the first time the efficiency, exploration dynamics and safety of the technique. DBE was successful in 83% of dogs; the average estimated insertion depth of the endoscope was 287±36cm, and the average duration of the exploration was 84±8min. No complications or relevant adverse clinical effects were observed, and there was no indication of post-procedure pancreatitis based on serology of two specific markers of pancreatitis (amylase and lipase) and the immediate nonspecific inflammatory mediator C-reactive protein. The study showed that oral DBE is viable and safe in the dog, allowing for the diagnosis and treatment of gastrointestinal diseases deep in the small intestine to an extent that has not previously been possible using conventional endoscopy.

Transesophageal access to the cardiac cavities and descending thoracic aorta via echoendoscopy. An experimental study

OBJECTIVE

The applications of endoscopic ultrasonography have diversified over recent years. The possibility of reaching cardiac territory has been successfully explored in experimental models, opening up a new field of possibilities for diagnostic and therapeutic interventions that were unthinkable until very recently. The aims set out in this study are to evaluate cardiac anatomy, its approach, the safety of the experimental procedure and the resulting morphological and histological changes after the procedure.

MATERIAL AND METHODS

The study has been performed on two adult pigs. They have undergone different surgical approaches to the cardiac cavities and descending thoracic aorta with excellent results.

RESULTS

Different cardiac structures have been identified and operated upon (right auricle, left auricle, left ventricle, cardiac valves), as well as major vessels. The use of contrast, both intracavitary and from a peripheral vein, enabled us to verify the anatomical spaces studied. During the procedures we monitored for arrhythmias, hemodynamic behavior, possibility of infection by obtaining sample hemocultures before and after procedures, and response to punctures.

CONCLUSIONS

The present study has enabled us to evaluate access to the heart from the esophageal lumen using endoscopic ultrasonography, with results that are very similar to those described in the current bibliography. However, we offer two novelties: puncture of the right auricle through the interauricular partition and puncture of the descending thoracic aorta, both performed with ease and apparent safety.

Tuberculous osteomyelitis of the knee

Tuberculosis is a mycobacterial infestation which generally involves the lungs. Primary bone tuberculosis without involving the joint is rare. A 35-year-old Pakistani immigrant presented with a mass and pain over the medial aspect of the knee that had persisted for 6 months. Clinical and radiological investigations revealed a tuberculous affectation of the distal epiphysis of the femur. We did not find any visceral organ involvement. Wide excision was performed, completed with antituberculostatic drugs for 9 months postoperatively. In the 2nd postoperative year, the patient was symptom-free, and the imaging test results were normal. Primary bone tuberculosis without joint affection is a rare presentation form of this disease and should be kept in mind in the diagnostic work-up of a mass of a bone lesion.

Polymorphism analysis of Epstein–Barr virus isolates of lymphoblastoid cell lines from patients with mycosis fungoides

In order to determine whether there is an association between the presence of Epstein–Barr virus (EBV) and mycosis fungoides (MF) disease progression, PCR was performed to detect the EBV status of 20 MF patients; six EBV-positive patients were found. EBV variants may differ in their biological properties, such as their ability to transform cells; therefore, the ability of these variants to immortalize B cells in vitro was analysed. Six continuously growing cell lines were obtained from prolonged cultures of unstimulated peripheral blood mononuclear cells that were taken from the six EBV-positive patients with MF. In order to characterize the EBV strains, EBNA-2 and LMP-1/LMP-2 gene polymorphisms in the six cell lines were also analysed. All patients were followed up for 10 years and it was noticed that EBV-positive patients had a poor prognosis with rapid disease progression and high mortality rates, compared to EBV-negative patients. EBV may therefore constitute a co-factor that accelerates the progression of disease.

Preventive effect of zaprinast and 3-isobutyl, 1-methylxanthine (phosphodiesterase inhibitors) on gastric injury induced by nonsteroidal antiinflammatory drugs in rats

Cyclic GMP plays an important role in maintaining homeostasis in the gastric mucosa. NSAIDs damage the mucosa by mechanisms that may be mediated by alterations in the intragastric concentration of cyclic GMP. To test this hypothesis we studied the effects of the oral administration of acetylsalicylic acid (100, 300, and 500 mg/kg), piroxicam (5, 10, and 20 mg/kg) and sodium diclofenac (10, 25, 50, and 100 mg/kg), and of their interaction with zaprinast (5 mg/kg) and IBMX (10 mg/kg), on intragastric concentrations of cyclic GMP and the gastric erosive index in rats. All determinations were done 3 hr after the NSAID was given. All NSAIDs induced dose-dependent decreases in mucosal concentrations of cyclic GMP, which correlated inversely with the surface area showing mucosal injury. In contrast, cyclic GMP concentrations remained normal, and no intragastric damage was seen in rats given zaprinast (cyclic GMP-specific phosphodiesterase inhibitor) or IBMX (non-specific phosphodiesterase inhibitor) or in combination with NSAIDs. These findings are in line with the hypothesis that cyclic GMP is involved in the biochemical mechanisms of NSAID-induced gastric injury.

A liver DNA synthesis promoter induced in rat plasma by injection of dimethylnitrosamine (DMNA) or thioacetamide

The appearance of a liver DNA synthesis promoter (HP) in rat plasma after dimethylnitrosamine (DMNA) or thioacetamide injection was investigated. After 48 h, DMNA (30 mg kg-1 body weight) produced liver (centrilobular) necrosis and intense hepatic regeneration, as assessed by microscopic observations of liver slices, as well as augmented transaminase levels; HP was detectable under these conditions. After 5 days, transaminases and HP returned to normal values (the latter undetectable), coinciding with a lack of necrotic zones. At 60 mg DMNA kg-1 body weight, necrotic areas were more marked and transaminases and HP levels higher after 48 h than with the lower dose; these increases were even more pronounced at 90 mg DMNA kg-1 body weight. After thioacetamide injection (200 mg kg-1 body wt) the situation at 48 h was very similar, with focal, centrilobular necrosis, frequent regenerative signs, high transaminases and detectable HP. Rats recovered after 7 days in a similar fashion as with DMNA. At 400 mg thioacetamide kg-1 body weight, necrotic areas and regeneration zones were more widespread and transaminases and HP higher after 48 h than with the lower dose. On account of the differing modes of action of DMNA and thioacetamide in rat liver, it is proposed that the appearance of HP activity in plasma could be related to the regenerative process that follows hepatotoxic damage.

Liver DNA synthesis promoter activity detected in human plasma from subjects with hepatitis

A liver DNA synthesis promoter activity was detected in human plasma from subjects with hepatitis. The assay procedure consisted of intraperitoneal injection into mice of aliquots of plasma, previously chromatographed on Sephadex G-25. After 24 hr, [3H]thymidine was injected and its incorporation into liver DNA measured. The increase in [3H]thymidine uptake of injected mice was not detected in those administered plasma from normal subjects (basal [3H]thymidine incorporation was that corresponding to saline-injected mouse values). At a maximal effective dose (0.3 mg protein per mouse), plasma from subjects with hepatitis increased the mitotic index of mouse liver hepatocytes; at the same dose, plasma from normal subjects had no effect. This DNA synthesis promoter activity appears to be a protein, as it is sensitive to trypsin digestion and heat.