Interventions for Managing Late Gastrointestinal Symptoms Following Pelvic Radiotherapy: a Systematic Review and Meta-analysis

AIMS

Pelvic radiotherapy can induce gastrointestinal injury and symptoms, which can affect quality of life. We assessed interventions for managing these symptoms.

MATERIALS AND METHODS

A review of randomised controlled trials published between January 1990 and June 2023 from databases including MEDLINE, EMBASE, CENTRAL, CINAHL, clinicaltrials.gov, ISRCTN and grey literature sources was conducted. Meta-analyses were carried out using the DerSimonian and Laird random effects model to produce overall treatment differences with 95% confidence intervals.

RESULTS

Twenty-eight studies (2392 participants) of varying methodological quality were included. 4% formalin was superior to sucralfate for improving gastrointestinal symptom score (standardised mean difference [SMD] -1.07, 95% confidence interval -1.48 to -0.65). Argon plasma coagulation (APC) was inferior to sucralfate (SMD 1.22, 95% confidence interval 0.84 to 1.59). Counselling positively influenced symptom score (SMD -0.53, 95% confidence interval -0.76 to -0.29), whereas hyperbaric oxygen therapy showed conflicting results. Sucralfate combined with APC increased endoscopic markers of moderate-severe bleeding versus APC alone (risk ratio 2.26, 95% confidence interval 1.12 to 4.55). No definite conclusions on pain, incontinence, diarrhoea, tenesmus or quality of life interventions were confirmed.

CONCLUSIONS

Small study sizes, methodological quality and heterogeneity limit support of any individual intervention. APC and 4% formalin seem to be promising interventions, with further larger randomised controlled trials now warranted.

Prevalence of zoonotic (brugian) filariasis in Asia: A proportional meta-analysis

Lymphatic filariasis is a public health problem and targeted for global elimination. WHO recommends mass drug administration to interrupt transmission of the parasites involved. There are concerns that transmission interruption may be difficult in areas of zoonotic filarial infections. This study aimed to estimate the pooled prevalence of zoonotic brugian filariasis, and to compare the pooled prevalence of brugian filariasis in human and animal populations in the same area based on available studies. A comprehensive literature search was conducted in health-related electronic databases (PubMed, Ovid MEDLINE, Index Medicus, google scholar). A random-effect meta-analysis of the pooled overall prevalence of filariasis in animal populations was conducted. Sixteen studies from four different Asian countries were identified. Studies were conducted most frequently in Thailand (n = 7), followed by Malaysia (n = 5), India (n = 3), and Sri Lanka (n = 1). Regardless of animal group, the pooled overall prevalence of animal Brugia infections was 13% (95%CI: 7-21%, I2:98%, 16 studies). On stratification, the pooled overall prevalence in the animal population was 19% (95%CI: 1-50%, I2: 99%, 3 studies) in India, 8% (95%CI: 2-7%, I2: 97%, 5 studies) in Malaysia, and 13% (95%CI: 7-20%, I2: 94%, 7 studies) in Thailand. The prevalence in the animal population was 17% (95%CI: 13-21%, 1 study) in Sri Lanka. The pooled overall prevalence of Brugia malayi was 13% (95%CI: 7-21%, I2:98%, 12 studies), while for Brugia pahangi this was 12% (95%CI: 7-19%, I2:86%, 7 studies). Regardless of animal group, geographic area, or diagnostic test, the prevalence of B. malayi was consistently high. On stratification by animal category, the pooled overall prevalence was 10% (95%CI: 6-14%, I2:92%, 13 studies) in cats, 12% (95%CI: 2-28%, I2: 99%, 6 studies) in dogs, and 55% (95%CI: 47-63%, 1 study) in leaf-eating monkeys. The findings show the extent of zoonotic Brugiainfections in domestic cats and dogs, suggesting that these animals are potential reservoirs for human brugian filariasis in the study countries. To substantiate this with more accuracy, future well designed whole genomic sequencing of individual mf collected from humans and B. malayi infected animals in the same area are needed.

Toll-like receptor 9 (-1237 T/C, -1486 T/C) and the risk of gastric cancer: a meta-analysis of genetic association studies

BACKGROUND

Gastric cancer has a complex aetiology including genetic factors. Individual case-control studies of toll like receptor (TLR) 9 (-1237 T/C, -1486 T/C) polymorphisms in the gastric cancer risk were available, and they showed variation in the findings. Therefore, we performed a meta-analysis to synthesize the evidence on the association between polymorphisms of TLR 9 (-1237 T/C, -1486 T/C) and the risk of gastric cancer using data from eligible studies.

METHODS

This study followed the PRISMA 2020 Checklist. Studies were searched in health-related databases. The methodological quality of studies was evaluated with the use of Newcastle-Ottawa Scale criteria. The summary odds ratio (OR) and its 95% confidence interval (CI) were used to determine the strength of association between each polymorphism and the risk of gastric cancer using five genetic models. Stratification was done by ethnic groups. For the robustness of the analysis, a leave-one-out meta-analysis was performed.

RESULTS

Eight case-control studies with 3,644 participants (1914 cases, 1730 controls) were conducted across six countries. Half of the studies were conducted in China. In the NOS methodological quality assessment, only three studies received a high-quality rating (i.e., a score of ≥ 7). TLR 9 (-1486 T/C) polymorphism and the risk of gastric cancer were assessed in six studies, four of Asian ethnicity and two of non-Asian. Under the dominant model, only in the Asian ethnic group showed a marginally and significantly increased risk of gastric cancer (overall: OR = 1.22, 95%CI = 0.90-1.67, I2 = 56%; Asian: OR = 1.24, 95%CI = 1.00-1.54, I2 = 0%, non-Asian: OR = 1.25, 95%CI = 0.38-4.09, I2 = 89%). Under the recessive model in the absence of heterogeneity, only the Asian group had a significantly higher risk of developing gastric cancer (overall: OR = 1.4, 95% CI = 0.74-2.64, I2 = 85%; Asian: OR: 1.41, 95% CI = 1.07-1.86, I2 = 0%, non-Asian: OR = 1.18, 95% CI = 0.12-11.76, I2 = 97%). Under the heterozygous model, there was no significant association with the risk of gastric cancer overall or among any ethnic subgroup. Under the homozygous model in the absence of heterogeneity, only the Asian group had a significantly higher risk of gastric cancer (overall, OR = 1.47, 95% CI = 0.76-2.86, I2 = 82%; Asian: OR = 1.54, 95% CI = 1.13-2.1, I2 = 0%; non-Asian: OR = 1.19, 95% CI = 0.1-14.33, I2 = 96%). Under the allele model, a significantly increased risk of gastric cancer was observed only in the Asian group (overall: OR = 1.23, 95% CI = 0.89-1.71, I2 = 84%; Asian: OR = 1.22, 95% CI = 1.05-1.41, I2 = 0%; non-Asian: OR = 1.24, 95% CI = 0.34-4.59, I2 = 97%). Four studies investigated the association between TLR 9 (-1237 T/C) polymorphism and the risk of developing gastric cancer. Under any of the five genetic models, there was no association between TLR 9 (-1237 T/C) and the development of gastric cancer in overall or in any ethnic subgroup. Sensitivity analysis revealed that the effect was unstable. With a small number of studies with a small number of participants, we addressed the issue of insufficient power for drawing conclusions.

CONCLUSIONS

The findings suggested that TLR9 (-1486 T/C) may play a role in the risk of gastric cancer specific to the Asian ethnic group. To substantiate the findings on the association between these two polymorphisms (TLR9 -1237 T/C, -1486 T/C) and the risk of gastric cancer, future well-designed case-control studies with a sufficient number of participants in multi-ethnic groups are recommended.

Facilitators and barriers to engaging communities in health service research on dengue control in Indo-Pacific region: a systematic review

BACKGROUND

Dengue is a public health problem in the Indo-Pacific countries. There are concerns over the facilitators and barriers to community engagement in health service research aimed at dengue control. The objective of his study was to identify and synthesize facilitators and barriers to community engagement in health service research aimed at dengue control.

METHODOLOGY

The Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) checklist was used to perform this review. Health-related databases including PubMed, Ovid, and Google Scholar were searched for relevant studies. A consolidated framework with five domains was developed after undertaking a six-phase reflective thematic assessment of the data.

RESULTS

Thirteen studies were identified, spanning eight low-and middle-income countries of the Indo-Pacific region including Cambodia, India, Indonesia, Myanmar, Philippines, Sri Lanka, Thailand, and Vietnam. The studies in this review covered the period from 2002 to 2021. A broad range of study designs and objectives were revealed across these 13 studies. An array of communities such as the local government, project-related health staff, local health services staff, community leaders, local communities/residences/general public, heads of households, community health volunteers, school teachers, and schoolchildren participated in these dengue related studies. The five Consolidated Framework for Implementation Research (CFIR) domains of 'intervention characteristics', 'inner setting', 'outer setting',' individual characteristics', and 'program implementations' were used to identify and describe barriers and facilitators.

CONCLUSIONS

The findings indicate a range of barriers and facilitators to community engagement in dengue control in the selected LMIC in the Indo-Pacific countries. Future health services research on dengue control approaches should be carefully planned, methodologically constructed, aligned with community engagement principles, and involve considerable community participation at all stages of the research.

Association between IL-10 gene polymorphisms (- 1082 A/G, -819 T/C, -592 A/C) and hepatocellular carcinoma: a meta-analysis and trial sequential analysis

BACKGROUND

The carcinogenesis of hepatocellular carcinoma is complicated, and genetic factor may have the role in the malignant transformation of liver cells. IL-10 gene polymorphisms have been investigated for their potential roles in hepatocellular carcinoma This study aimed to investigate the relationship between polymorphisms of IL-10 (-1082 A/G, -819 T/C, -592 A/C), and hepatocellular carcinoma by performing a meta-analysis with eligible individual studies.

METHODS

This study followed the PRISMA 2020 Checklist. Relevant studies were searched in health-related databases. The Newcastle-Ottawa Scale criteria were used to evaluate the studies quality. Pooled odds ratio (OR) and its 95% confidence interval (CI) were used to determine the strength of association between each polymorphism and hepatocellular carcinoma using five genetic models. Stratification was done by ethnic groups. Trial sequential analysis (TSA) was performed to determine the required information size.

RESULTS

Fifteen case-control studies (n = 8182) were identified. Overall, the heterozygous model showed a marginal significant association only between IL-10 (-1082 A/G) and hepatocellular carcinoma risk (OR: 0.82, 95% CI: 0.67-1.00, 9 studies). On stratification, IL-10 (-1082 A/G) was significantly associated with hepatocellular carcinoma risk in the non-Asian population under dominant (OR: 0.62, 95% CI: 0.45-0.86, 4 studies), heterozygous (OR: 0.60, 95% CI: 0.43-0.85) and allelic models (OR: 0.79, 95% CI: 0.64-0.99). IL-10 (-819 T/C) was significantly associated with hepatocellular carcinoma risk only among non-Asians under the dominant (OR: 1.47, 95% CI: 1.02-2.13, 8 studies), recessive (OR: 1.99, 95% CI: 1.03-3.86, and homozygous models (OR: 2.18, 95% CI: 1.13-4.23). For IL-10 (-592 A/C) with 11 studies, there was no significant association with hepatocellular carcinoma in all five genetic models (P values > 0.5). TSA plots indicated that the information size for firm evidence of effect was sufficient only for the analysis of IL-10 (-592 A/C), but not for the - 1082 A/G or -819 T/C.

CONCLUSIONS

Findings suggest that IL-10 (-1082 A/G and - 819 T/C) polymorphisms are associated with hepatocellular carcinoma in ethnic-specific manner. However, this evidence is not conclusive because the sample size was insufficient. IL-10 (-592 A/C) polymorphism was not associated with hepatocellular carcinoma albeit with sufficient information size. Future well-designed large case-control studies on IL-10 (-1082 A/G and - 819 T/C) with different ethnicities are recommended.

Community engagement in health services research on soil-transmitted helminthiasis in Asia Pacific region: Systematic review

The research question was what studies are available that have assessed community engagement in the health services research on soil-transmitted helminths? We aimed to synthesise evidence on how communities were engaged in health services research on soil-transmitted helminths in low-and-middle-income countries of the Asia-Pacific Region. We focused on this region because soil-transmitted helminths are endemic, and their burden is significant in this region. This review was conducted according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) checklist. Relevant studies were searched in health-related databases including PubMed, Ovid, and Google Scholar. We selected studies based on the selection criteria set for this review. We collected textual information about the type of health services research, the degree of community engagement, the research phases involved, and the barriers/enablers affecting community engagement in research since they are pertinent to our review question and objective. Ten studies from seven countries in the Asia Pacific region were identified for this review. Albeit with variation in the extent of their involvement, various forms of communities/groups within communities were included such as Aboriginal communities, local communities, school children and their parents, school teachers and headmasters of schools, heads of villages, religious leaders, and so on. Overall, community engagement in health services research focused on of soil-transmitted helminths was limited. Six studies (60%) had collaboration at ‘developing methodology’, mainly through an explanation of the objectives of the study or study process to be conducted. Seven studies (70%) revealed community participation in soil-transmitted helminths at the “data collection” stage. Only one study (10%) documented that a community leader was involved as a co-author, reflecting an involvement in ‘report writing’ and further ‘dissemination’. Findings suggest that there were various forms of community engagement in various aspects of the health services research context. Overall, there was moderate level of participation, but there was insufficient information on the partnership between various stakeholders, which prevented in-depth analysis of the engagement. Future health services research on soil-transmitted helminth interventions needs to be carefully planned, well designed, grounded in principles of community engagement, and designed methodologically to allow in-depth participation by communities in all stages of the research.

Loop-mediated isothermal amplification (LAMP) test in the detection of uncomplicated malaria in pregnancy: a meta-analysis of diagnostic accuracy

BACKGROUND

Due to relatively low malaria parasitaemia in pregnancy, an appropriate field test that can adequately detect infections in pregnant women presenting with illness or for malaria screening during antenatal care is crucially important. The objective was to evaluate the diagnostic accuracy of loop-mediated isothermal amplification (LAMP) for the detection of uncomplicated malaria in pregnancy.

METHODS

This was a meta-analysis of diagnostic accuracy. Relevant studies that assessed the diagnostic performance of LAMP for the detection of malaria in pregnancy were searched in health-related electronic databases including PubMed, Ovid, and Google Scholar. The methodological quality of the studies included was evaluated using the QUADAS-2 tool.

RESULTS

Of the 372 studies identified, eight studies involving 2999 pregnant women in five endemic countries that assessed the accuracy of LAMP were identified. With three types of PCR as reference tests, the pooled sensitivity of LAMP was 91% (95%CI 67-98%) and pooled specificity was 99% (95%CI 83-100%, 4 studies), and the negative likelihood ratio was 9% (2-40%). Caution is needed in the interpretation as there was substantial between-study heterogeneity (I²: 80%), and a low probability that a person without infection is tested negative. With microscopy as a reference, the pooled sensitivity of LAMP was 95% (95%CI 26-100%) and pooled specificity was 100% (95%CI 94-100%, 4 studies). There was a wide range of sensitivity and substantial between-study heterogeneity (I²: 83.5-98.4%). To investigate the source of heterogeneity, a meta-regression analysis was performed with covariates. Of these potential confounding factors, reference test (p: 0.03) and study design (p:0.03) had affected the diagnostic accuracy of LAMP in malaria in pregnancy. Overall, there was a low certainty of the evidence in accuracy estimates.

CONCLUSION

The findings suggest that LAMP is more sensitive than traditional tests used at facilities, but the utility of detecting and treating these low-density infections is not well understood. Due to the limited number of studies with bias in their methodological quality, variation in the study design, and different types of reference tests further research is likely to change the estimate. Well-conceived large prospective studies with blinding of the index test results are recommenced.

Association of tumour necrosis factor-α (TNF-α) gene polymorphisms (-308 G>A and -238 G>A) and the risk of severe dengue: A meta-analysis and trial sequential analysis

Individual studies have assessed the association between TNF-α-308G>A and TNF-α-238 G>A polymorphisms and severity of dengue infection. However, the results are inconclusive and most studies had small sample sizes. The objective of this study was to summarize the evidence of association between TNF-α-308 G>A and TNF-α-238 G>A and severity of dengue infection. This study follows the preferred reporting items for systematic reviews and meta- analyses of genetic association studies, recommended by PLOS One. We calculated pooled odds ratio and its 95% confidence interval (CI) to estimate the association between TNF-α-308 G>A or TNF-α-238 G>A and the risk of severe dengue infections. To determine the information size required for this meta-analysis study, a trial sequential analysis (TSA) was done. Eight studies (640 cases and 1275 controls), which assessed the association of TNF-α-308 G>A or TNF-α-238 G>A and the risk of DHF were included. Overall, we found no significant association between TNF-α-308 G>A and the DHF risk in the allelic model (OR, 0.91; 95% CI, 0.51-1.63), the recessive model (OR,1.32;95%CI,0.73-2.37), the dominant model (OR,0.93;95%CI:0.59-1.47) or the additive model (OR,1.43,95;95%CI:0.79-2.59). There was also no significant association between TNF-α-238 G>A and DHF risk under the allele contrast model (OR:1.51;95%CI:0.88-2.58), the recessive model (OR,1.48,95% CI:0.33-6.58), the dominant model (OR,1.48;95%CI:0.56-3.92), or the additive model (OR:1.5;95%CI:0.34-6.69). On subgroup analysis, neither the Asian population nor the non-Asian population showed significant association between TNF-α-308 G>A/TNF-α-238 G>A and the DHF risk under any genetic models. Leave-one-out meta-analysis showed stability of the results. TSA plots suggested that the sample size in this meta-analysis study was below the required information size. The findings suggest an inclusive evidence of the association between TNF-α-308/ TNF-α-238 G>A and the risk of developing severe dengue infection. Large studies with evidence of Hardy-Weinberg equilibrium, assessing gene-gene interactions are recommended.

DNA vaccine constructs against enterovirus 71 elicit immune response in mice

Background

Enterovirus 71 (EV71) is a major causative viral agent responsible for large outbreaks of hand, foot and mouth disease (HFMD), a common rash illness in children and infants. There is no effective antiviral treatment for severe EV71 infections and no vaccine is available. The objectives of this study were to design and construct a DNA vaccine against Enterovirus 71 using the viral capsid protein (VP1) gene of EV71 and to verify the functionality of the DNA vaccine in vitro and in vivo.

Methods

The VP1 gene of EV71 from two local outbreak isolates were amplified using PCR and then inserted into a eukaryotic expression vector, pVAX1. The 3.9 kb recombinant constructs were transformed into competent E. coli cells and the positive clones were screened and selected using PCR analysis, restriction digestion analysis and DNA sequencing. The constructs were then tested for protein expression in Vero cells. Subsequently, in the in vivo studies, female Balb/c mice were immunized with the DNA vaccine constructs. Enzyme Linked Immunosorbent Assay (ELISA) and virus neutralizing assay were performed to detect the presence of anti-VP1 IgG in mice and its neutralizing effect against the EV71.

Results

The pVAX1 vector was successfully cloned with the VP1 gene from each of the isolate (S2/86/1 and 410/4) in the correct orientation and in-frame. The DNA vaccine constructs with the VP1 gene were shown to be expressed in a cell-free in vitro expression system. The VP1 protein was successfully expressed in the mammalian cell line and was detected using RT-PCR, Indirect Immunofluorescence Assay (IFA) and western blotting. The anti-VP1 IgG levels in mice immunized with the DNA vaccine constructs increased after the first booster but declined following the second booster. The anti-VP1 IgG in the mice immunized with the DNA vaccine constructs exhibited neutralising activity against EV71.

Conclusion

The promising results obtained in the present study have prompted further testing to improve the expression and immunogenicity of this potential EV71 DNA vaccine.

Simultaneous analysis of 1176 gene products in normal human aorta and abdominal aortic aneurysms using a membrane-based complementary DNA expression array

BACKGROUND

A number of changes in gene expression have been described in abdominal aortic aneurysms (AAAs), but the spectrum of molecular alterations in this disease is unknown. The purpose of this study was to characterize the expression of approximately 1000 gene products in human AAA tissue and to compare the profile of genes expressed in AAAs with that observed in normal aorta.

MATERIALS AND METHODS

Total RNA was isolated from abdominal aortic wall tissues (4 AAAs and 4 normal aortas), and array-specific [(32)P]-labeled complementary DNA (cDNA) probes were created with reverse transcription. The cDNA probes were hybridized with nylon membranes containing an array of 1176 cDNA clones (AtlasArray Human 1.2 I; Clontech, Palo Alto, Calif), and autoradiographs were scanned to identify the patterns of gene expression characteristic of each tissue type. Densitometric analysis was used to standardize the expression of individual genes to a panel of housekeeping controls, and differential gene expression was defined by a signal ratio of at least 2:1.

RESULTS

One hundred forty-five (12.3%) of the 1176 genes were consistently expressed in aortic tissue. Thymosin beta-4 was the most abundant of 101 transcripts detected in both AAAs and normal aorta, whereas 44 genes exhibited differential patterns of expression (39 predominant in AAAs and 5 in normal aorta). Densitometric analysis confirmed differences in expression for 20 of these gene products between AAAs and normal aorta, with the greatest increases seen for myeloid cell nuclear differentiation antigen (31-fold), cathepsin H (30-fold), platelet-derived growth factor-A (23-fold), apolipoprotein E (13-fold), gelatinase B/matrix metalloproteinase-9 (12-fold), and interleukin-8 (11-fold). The only gene products substantially decreased in AAAs were myosin light chain kinase (39-fold) and beta-1 integrin (twofold). AAA tissues thereby exhibited a distinct pattern of gene expression reflecting chronic inflammation, extracellular matrix degradation, atherosclerosis, and smooth muscle cell depletion.

CONCLUSIONS

cDNA expression arrays provide a powerful new approach to help identify the molecular mechanisms responsible for aneurysmal degeneration. Further studies will be needed to elucidate the functional and pathophysiologic significance of the individual genes that exhibit altered levels of expression in AAA tissue.

Allelotype of follicular thyroid carcinomas reveals genetic instability consistent with frequent nondisjunctional chromosomal loss

Numerous studies aimed at the identification of chromosomal regions that are frequently deleted in specific tumor types have pointed to the location and involvement of specific tumor suppressor genes. Previous studies of loss of heterozygosity (LOH) among thyroid tumors have revealed frequent allelic deletions at a few chromosomal regions. A systematic genome-wide examination of LOH in a substantial number of follicular carcinomas, however, has not been performed previously. We assessed LOH at polymorphic markers from each nonacrocentric autosomal arm in a panel of 28 follicular thyroid carcinoma tumor and normal pairs. In contrast to the results of previous allelotype studies, we found high rates of LOH at multiple chromosomal regions. The highest rate of loss in our study was at 2p (50.0%), and 2q (50.0%), and the mean rate of LOH was 20.4%. Marked genetic instability in a subset of tumors was demonstrated by high fractional allelic loss, which accounted for more than 80% of observed LOH in this study. High fractional allelic loss was significantly associated with oxyphilic features and poor differentiation of these tumors. Our data provide evidence of a prevalent phenotype of nondisjunctional whole chromosomal loss in follicular thyroid carcinomas.

Infrequent CDKN2 mutation in human differentiated thyroid cancers

We examined the frequency of cyclin-dependent kinase (CDK) N2 alterations in differentiated and anaplastic thyroid cancers to assess the involvement of CDKN2 in the development of these cancers. The CDKN2 gene, which encodes the cell-cycle regulator p16, was recently shown to be mutated or deleted in many tumor cell lines. Its role in the genesis of primary tumors is uncertain, however. Tumor and corresponding normal DNAs were prepared by microdissection of paraffin-embedded tissue blocks or from frozen surgical specimens of 15 papillary, 15 follicular, and five anaplastic thyroid carcinomas. The entire CDKN2 coding region was screened by single-strand conformational variant analysis and direct sequencing of variants. The presence of homozygous deletions was evaluated by multiplex polymerase chain reaction (PCR) analysis. Loss of heterozygosity (LOH) in the CDKN2 region was assessed by using flanking polymorphic markers. Two somatic missense mutations were found among the 35 thyroid cancers, one in a follicular tumor and one in an anaplastic tumor. Multiplex PCR suggested the presence of homozygous deletion in one anaplastic tumor and hemizygous deletions in four tumors. LOH studies revealed loss of 9p sequences in four follicular (27%) and two anaplastic (50%) cancers. Our data suggest that alterations in CDKN2 played a role in a minority of thyroid cancers (three of 35). LOH in the region of CDKN2 is seen in a significant proportion of follicular and anaplastic but not papillary cancers. Loss of 9p sequences suggests a role for a tumor suppressor gene in the development of follicular and anaplastic thyroid cancers.

Laparoscopic detection of hepatic metastases in patients with residual or recurrent medullary thyroid cancer

BACKGROUND

After initial operations for medullary thyroid cancer (MTC), reoperation with removal of metastatic disease confined to the neck may benefit some patients. The identification of distant metastases precludes the possibility of curative reoperation.

METHODS

Forty-one patients with hypercalcitoninemia after initial surgical treatment for MTC underwent laparoscopic (n = 36) or open (n = 5) examination and biopsy of the liver. Thirty-seven of these patients underwent imaging by computed tomography (CT), magnetic resonance imaging (MRI) of the liver, or both, and 17 underwent selective venous catheterization (SVC) with measurement of hepatic and peripheral vein stimulated calcitonin levels.

RESULTS

Liver metastases were found in eight patients, seven by laparoscopy and one by open examination. Seven of these patients had normal CT or MRI scans of the liver. Laparoscopy or open liver examination revealed metastases in 2 of 11 patients with elevated hepatic vein-peripheral vein stimulated calcitonin ratios (greater than 1.3). Metastases appeared as small (less than 5 mm), bright white nodules on the surface of the liver.

CONCLUSIONS

Direct examination and biopsy of the liver by laparoscopy may show small deposits of metastatic MTC in patients with normal CT and MRI scanning.

Frequent mutations of CDKN2 in primary pancreatic adenocarcinomas

The gene encoding the cell-cycle regulatory protein p16, CDKN2, is localized on chromosome band 9p21. CDKN2 is frequently deleted or mutated in a variety of tumor cell lines, including pancreatic cancer cell lines and xenografts, as well as in some primary tumors. We examined 32 primary pancreatic adenocarcinomas for CDKN2 mutations and for loss of heterozygosity of 9p21 sequences to assess the role of CDKN2 in pancreatic carcinogenesis. Single-strand conformation variant analysis (SSCV) and direct sequencing of the variants revealed somatic CDKN2 mutations in 11 of 32 tumors (five frame-shift mutations, five nonsense mutations, and one missense mutation). One tumor appeared to be characterized by homozygous deletion of CDKN2. These results suggest that CDKN2 plays an important role during tumorigenesis or tumor progression in a significant proportion of pancreatic adenocarcinomas.

Histamine-2-receptor blockade does not affect hyperemia after cerebral ischemia in young swine

OBJECTIVE

To determine whether histamine-2 (H2) receptor antagonists can blunt the increase in cerebral blood flow after cerebral ischemia.

DESIGN

Prospective, randomized trial.

SETTING

Animal laboratory.

SUBJECTS

Piglets aged 1 to 2 wks.

INTERVENTIONS

Three groups of piglets were anesthetized with pentobarbital, mechanically ventilated, and hemodynamically monitored. Each animal was randomized to receive one of three treatments 20 mins before ischemia: famotidine (0.6 mg/kg i.v.), cimetidine (5 mg/kg i.v.), or an equivalent volume of saline (3 mL). Ischemia was maintained for 15 mins by tightening ligatures around the brachiocephalic trunk and left subclavian arteries plus the induction of hemorrhagic hypotension (50 mm Hg). Reperfusion was initiated by the reinfusion of shed blood and removal of the ligatures.

MEASUREMENTS AND MAIN RESULTS

The three groups were not different with regard to baseline arterial blood gases, cerebral perfusion pressure, microsphere-determined cerebral blood flow, or oxygen consumption (VO2). Ischemia (cerebral blood flow < 5 mL/min/100 g of tissue) was demonstrated in all brain regions for all groups during arterial ligation with hemorrhage-induced hypotension. Blood flow rates were increased compared with preischemic values in all regions at 7 mins of reperfusion. For example, mean forebrain blood flow rates increased from 36 +/- 3 to 95 +/- 14 (SEM) mL/min/100 g of tissue in the group receiving saline, from 36 +/- 3 to 102 +/- 9 mL/min/100 g of tissue in the group receiving famotidine, and from 31 +/- 4 to 119 +/- 26 mL/min/100 g in the group receiving cimetidine. Overall, the three groups did not differ in regard to blood flow rates and cerebral VO2 values during ischemia and at 30 mins of reperfusion.

CONCLUSIONS

We demonstrated that famotidine or cimetidine as compared with saline did not affect the pattern or extent of hyperemia after ischemia. This finding does not support the hypothesis that a H2-receptor mechanism is necessary for postischemic hyperemia.