Minimally invasive right colectomy with transrectal natural orifice extraction: could this be the next step forward?

Background

The transvaginal natural orifice specimen extraction (NOSE) approach for right-side colon surgery has been proven to exhibit favorable short-term outcomes. However, thus far, no study has reported the advantages of transrectal NOSE for right-side colon surgery. The aim of this study was to compare the technical feasibility, safety, and short-term outcomes of minimally invasive right hemicolectomy using the transrectal NOSE method and those of conventional mini-laparotomy specimen extraction.

Methods

A study was conducted on consecutive patients who had minimally invasive right hemicolectomy either for malignancy or benign disease at Chang Gung Memorial Hospital, Linkou, Taiwan, between January 2017 and December 2018. The patients were divided into two groups: conventional surgery with specimen extraction using mini-laparotomy and NOSE surgery. Surgical outcomes, including complications, postoperative short-term recovery, and pain intensity, were analyzed.

Results

We enrolled 297 patients (151 males, mean age 64.9 ± 12.8 years) who had minimally invasive right hemicolectomy. Of these 297 patients, 272 patients had conventional surgery with specimen extraction through mini-laparotomy and 25 patients had NOSE surgery (23 transrectal, 2 transvaginal). The diagnosis of colon disease did not differ significantly between the conventional and NOSE groups. Postoperative morbidity and mortality rates were comparable. The postoperative hospital stay was significantly (p = 0.004) shorter in the NOSE group (median 5 days, range 3–17 days) than in the conventional group (median 7 days, range 3–45 days). Postoperative pain was significantly (p = 0.026 on postoperative day 1 and p = 0.002 on postoperative day 2) greater in the conventional group than in the NOSE group.

Conclusions

NOSE was associated with acceptable short-term surgical outcomes that were comparable to those of conventional surgery. NOSE results in less postoperative wound pain and a shorter hospital stay than conventional surgery. Larger studies are needed

Antibacterial activity of viable and heat-killed probiotic strains against oral pathogens

Probiotics can stabilize gut flora, regulate intestinal immunity and protect the host from enteric diseases; however, their roles in oral health have received little attention compared to their roles in gut health. Nowadays, the prevalence of sugar-sweetened foods and abuse of antibiotics contribute towards dysbiosis of oral microbiota and drug resistance development in oral pathogens, resulting in various intractable oral diseases. We screened the antibacterial activities of viable and heat-killed probiotic strains against the oral pathogens Streptococcus mutans, Porphyromonas gingivalis, Fusobacterium nucleatum and Aggregatibacter actinomycetemcomitans. The probiotic strains Lactobacillus salivarius subsp. salicinius AP-32, L. rhamnosus CT-53, L. paracasei ET-66 and Bifidobacterium animalis subsp. lactis CP-9 displayed strong antipathogenic activities, whereas heat-killed AP-32, CT-53 and ET-66 displayed high levels of pathogen inhibition. The antibacterial activities of these probiotics were not associated with their H₂ O₂ production; L. acidophilus TYCA02 produced high levels of H₂ O₂ but merely exhibited moderate antibacterial activities. Oral tablets containing probiotics showed positive inhibitory effects against oral pathogens, particularly those containing viable probiotics. Our results indicate that probiotics prevent the growth of oral pathogens and improve oral health, providing insights into the antipathogenic efficacy of different probiotic species and their potential role in functional foods that improve oral health. SIGNIFICANCE AND IMPACT OF THE STUDY: Our study provides insights into the antipathogenic efficacy of different probiotic species and their potential roles in developing functional foods to improve oral health. We showed that the probiotic strains Lactobacillus salivarius subsp. salicinius AP-32, L. rhamnosus CT-53, L. paracasei ET-66 and Bifidobacterium animalis subsp. lactis CP-9 have great potential for use in the development of functional foods to improve oral health. Since active probiotics may provide strong and long-term protection, the development of functional food products should favour the use of viable bacteria.

Pre-operative serum albumin level substantially predicts post-operative morbidity and mortality among patients with colorectal cancer who undergo elective colectomy

The quantitative relationship between serum albumin level and surgical outcomes has not been clearly established. This study included 3732 patients with colon cancer who underwent a potentially curative colectomy. Post-operative mortality and morbidity were analysed according to the patients' demographic data, pre-operative comorbidities, and tumour-related factors. Age, asthma, renal impairment, and albumin level were significantly associated with post-operative morbidity and mortality in the multivariate analyses. Logistic regression analysis revealed linear relationships of post-operative morbidity and mortality with albumin level. The morbidity and mortality rates decreased by 7.3% and 15.6%, respectively, for each 0.1 g/dL increase in albumin level. This finding remained significant in the hypoalbuminaemia subgroup but not in the normoalbuminaemia subgroup. That is, the morbidity and mortality rates significantly decreased by 8.7% and 17.7%, respectively (both P < 0.001), in the former group and decreased by 2.7% (P = 0.112) and 11.6% (P = 0.092), respectively, in the latter group. This study demonstrated that serum albumin level linearly predicted the post-operative morbidity and mortality among the colorectal cancer patients. Pre-operative serum albumin level may therefore be used as a continuous rather than a categorical marker of disease severity, especially among patients with hypoalbuminaemia.

Solid freeform-fabricated scaffolds designed to carry multicellular mesenchymal stem cell spheroids for cartilage regeneration

Three-dimensional (3D) cellular spheroids have recently emerged as a new trend to replace suspended single cells in modern cell-based therapies because of their greater regeneration capacities in vitro. They may lose the 3D structure during a change of microenvironment, which poses challenges to their translation in vivo. Besides, the conventional microporous scaffolds may have difficulty in accommodating these relatively large spheroids. Here we revealed a novel design of microenvironment for delivering and sustaining the 3D spheroids. Biodegradable scaffolds with macroporosity to accommodate mesenchymal stem cell (MSC) spheroids were made by solid freeform fabrication (SFF) from the solution of poly(D,L-lactide-co-glycolide). Their internal surface was modified with chitosan following air plasma treatment in order to preserve the morphology of the spheroids. It was demonstrated that human MSC spheroids loaded in SFF scaffolds produced a significantly larger amount of cartilage-associated extracellular matrix in vitro and in NOD/SCID mice compared to single cells in the same scaffolds. Implantation of MSC spheroid-loaded scaffolds into the chondral defects of rabbit knees showed superior cartilage regeneration. This study establishes new perspectives in designing the spheroid-sustaining microenvironment within a tissue engineering scaffold for in vivo applications.

Suppressive effect of COX2 inhibitor on the progression of adipose inflammation in high-fat-induced obese rats

BACKGROUND

The aim was to examine whether the inhibition of selective cyclooxygenase (COX) 2 activation could suppress the development of inflammatory reaction in visceral and subcutaneous abdominal fats of high-fat-induced obese rats.

MATERIALS AND METHODS

The rats were fed separately regular diet (CONT), high-fat diet ad libitum or energy-restrictedly (HFr) for 12 weeks. Rats fed high-fat diet ad libitum were further divided into those co-treated with vehicle (HFa), a selective COX2 inhibitor-celecoxib (HFa-Cel) or nimesulide (HFa-Nim). Oral glucose tolerance test (OGTT) was performed at the end of weeks 4, 8, 12. Another set of rats with similar grouping was divided into those with a 4-, 8- or 12-week intervention for tissue sampling.

RESULTS

Body and epididymal fat weights were increased similarly in HFa, HFa-Cel and HFa-Nim. Time-dependent increases in plasma insulin, triglyceride, impaired OGTT shown in HFa were significantly reversed in HFa-Cel and HFa-Nim. The obese-linked increases in gene expressions of COX-2, monocyte chemoattractant protein-1 (MCP-1) and tumour necrosis factor-alpha (TNF-alpha) in epididymal and subcutaneous fats (especially in the former) were significantly suppressed in HFa-Cel and HFa-Nim. The protein contents of MCP-1 and TNF-alpha in epididymal fats were changed consistently with their gene expressions. Plasma MCP-1 was increased time-dependently in HFa and suppressed in HFa-Cel and HFa-Nim. The increased CD68 positive cells showed in both epididymal and subcutaneous fats of HFa were significantly attenuated in HFa-Cel and HFa-Nim.

CONCLUSIONS

Our findings suggest that COX2 activation is crucially involved in the development of inflammatory response in adipose tissues of high-fat-induced obese rats.

Mutation analysis of the APC gene in Taiwanese FAP families: low incidence of APC germline mutation in a distinct subgroup of FAP families

Familial adenomatous polyposis (FAP) is an autosomal-dominant disease caused by germline mutations in the adenomatous polyposis coli (APC) gene. The affected individuals develop colorectal polyposis and show various extra-colonic manifestations. In this study, we aimed to investigate the genetic and clinical characteristics of FAP in Taiwanese families and analyze the genotype-phenotype correlations. Blood samples were obtained from 66 FAP patients registered in the hereditary colorectal cancer database. Then, germline mutations in the APC genes of these 66 polyposis patients from 47 unrelated FAP families were analyzed. The germline-mutation-negative cases were analyzed by performing multiplex ligation-dependent probe amplification (MLPA) and single-strand conformation polymorphism (SSCP) analysis of the MUTYH gene. Among the analyzed families, 79% (37/47) of the families showed 28 APC mutations, including 19 frameshift mutations, 4 nonsense mutations, 3 genomic deletion mutations, 1 missense mutation, and 1 splice-site mutation. In addition, we identified 15 novel mutations in 32% (15/47) of the families. The cases in which APC mutations were not identified showed significantly lower incidence of profuse polyposis (P = 0.034) and gastroduodenal polyps (P = 0.027). Furthermore, FAP families in which some affected individuals had less than 100 polyps showed significant association with low incidence of APC germline mutations (P = 0.002). We have added the APC germline-mutation data for Taiwanese FAP patients and indicated the presence of an FAP subgroup comprising affected individuals with nonadenomatous polyps or less than 100 adenomatous polyps; this form of FAP is less frequently caused by germline mutations of the APC gene.

Selective COX2 inhibition improves whole body and muscular insulin resistance in fructose-fed rats

BACKGROUND

The effects of cyclooxygenase-1 (COX1) and cyclooxygenase-2 (COX2) inhibition on insulin resistance in subjects with the metabolic syndrome remain elusive. Aims of this study were to examine the effects of COX1 and COX2 inhibitors on whole body and muscular insulin resistance in fructose-fed rats, an animal model of the metabolic syndrome.

MATERIALS AND METHODS

The rats on regular or 60% fructose-enriched diets for 6 weeks were further divided into rats combined with or without piroxicam (a selective COX1 inhibitor) or celecoxib (a selective COX2 inhibitor) treatment for an additional 2 weeks. Euglycaemic hyperinsulinaemic clamp (EHC) with a tracer dilution method was performed at the end of the study.

RESULTS

The present result showed that fructose-induced increases in systolic blood pressure and fasting plasma insulin levels were significantly suppressed in rats treated with celecoxib but not piroxicam. In the EHC period, celecoxib significantly reversed fructose-induced decreases in whole body glucose uptake, mainly by glucose storage. Hepatic glucose production and whole body glycolysis were not significantly changed among groups. Celecoxib but not piroxicam significantly reversed fructose-induced decreases in glycogen synthase activities in red and white quadriceps muscles and insulin-stimulated membrane GLUT4 recruitment in soleus muscles. Celecoxib and piroxicam both significantly diminished fructose-induced increases in plasma thromboxane B2 and 6-keto prostaglandin (PG) F1alpha; but only celecoxib treatment significantly attenuated a fructose-induced increase in 8-isoprostane levels. Plasma PGE metabolites were not different among groups.

CONCLUSIONS

This study demonstrates that a therapeutic dose of celecoxib, but not piroxicam, could significantly attenuate fructose-induced whole body and muscular insulin resistance in rats.

Mild portal endotoxaemia induces subacute hepatic inflammation and pancreatic beta-cell dysfunction in rats

BACKGROUND

Portal endotoxaemia has been speculated to be crucially involved in the pathogenesis of chronic hepatic inflammation, which is highly associated with the development of type 2 diabetes mellitus. This study tests whether portal endotoxaemia is a pathogenic link between chronic subacute hepatic inflammation and pancreatic beta-cell dysfunction.

MATERIALS AND METHODS

Rats were randomly assigned into two groups: rats with intraportal saline or low-dose lipopolysaccharide (LPS) infusion for 4 weeks. Pathological changes in the liver were evaluated via histological and biochemical examination. Pancreatic insulin secretion was evaluated by in vivo hyperglycaemic clamp study.

RESULTS

White blood cell count was significantly increased after intraportal LPS infusion for 4 weeks. Plasma amylase and chemoluminescence counts indicating superoxide levels were significantly increased after LPS treatments for 2 and 4 weeks. Intraportal low-dose LPS infusion significantly increased tumour necrosis factor-alpha and interleukin-6 contents in liver and pancreas. Circulating C-reactive protein, thiobarbituric acid reactive substances (TBARS) and endotoxin levels were not different among groups. The first- and second-phase insulin secretions in hyperglycaemic clamp were significantly decreased in LPS-treated rats. The histopathological scores, de novo production of reactive oxygen substrate and TBARS contents in the liver and pancreas were significantly increased in LPS-infused rats. Leucocyte infiltration was clearly visible in pancreatic islets of LPS-treated rats.

CONCLUSIONS

The present study demonstrated that mild portal endotoxaemia caused subacute hepatic inflammation and impaired pancreatic insulin secretion, implicating that portal endotoxaemia is a potential risk factor to link chronic subacute hepatic inflammation and pancreatic beta-cell dysfunction.

Association study of genetic polymorphisms of SLC2A10 gene and type 2 diabetes in the Taiwanese population

AIMS/HYPOTHESIS

The gene encoding solute carrier family 2, facilitated glucose transporter, member 10 (SLC2A10, previously known as glucose transporter 10 [GLUT10]) is a promising candidate gene for type 2 diabetes since it is highly expressed in liver and pancreas and is located on human chromosome region 20q12-q13.1, a region previously shown to harbour type 2 diabetes susceptibility genes. We investigated whether the SLC2A10 gene could be a type 2 diabetes susceptibility gene in the Taiwanese population.

SUBJECTS AND METHODS

Sequencing of SLC2A10 gene from 48 diabetic subjects detected short tandem repeat polymorphisms in the promoter region, but did not detect any other sequence variants or new single-nucleotide polymorphisms (SNPs) other than those already in the SNPper database ( http://snpper.chip.org ) (30 June 2005).

RESULTS

Using these genetic polymorphisms, we divided the SLC2A10 gene into four distinct linkage disequilibrium blocks and performed a case-control association study in a group of type 2 diabetes subjects (n = 375) and normoglycaemic individuals (n=377). The HapD (A-G-T-C) haplotype in block 3, a rare haplotype, which consisted of four SNPs (rs3092412, rs2235491, rs2425904 and rs1059217), was modestly associated with type 2 diabetes with a haplotype score of -2.95567 (p = 0.012 with the haplotype-specific test).

CONCLUSIONS/INTERPRETATION

Our results suggest that SLC2A10 genetic variations do not appear to be major determinants for type 2 diabetes susceptibility in the Taiwanese population.

Distribution of human chemokine (C-X3-C) receptor 1 (CX3CR1) gene polymorphisms and haplotypes of the CC chemokine receptor 5 (CCR5) promoter in Chinese people, and the effects of CCR5 haplotypes on CCR5 expression

Two chemokine (C-X3-C) receptor 1 (CX3CR1) gene polymorphisms, V249I and T280M, and 10 CC chemokine receptor 5 (CCR5) promoter haplotypes, P1-P10, have recently been reported to influence the progression of acquired immune-deficiency syndrome (AIDS). As these studies were performed mainly with Caucasian and African-American subjects, we determined the distribution of these alleles in Chinese people for the purpose of predicting possible clinical responses to the human immunodeficiency virus type 1 (HIV) epidemics in countries with significant Chinese populations, as well as to establish their effects on the expression of surface CCR5. Ninety-six HIV-negative Chinese individuals in Taiwan were subjected to genotyping, and we thus determined that the allelic frequencies of CX3CR1V249I and T280M changes were 2.6% and 2.1%, respectively, which were lower than found in Caucasians (25.5% and 14.0%, respectively). Unlike the previous reports, we only detected CCR5P1 and P4 haplotypes in Taiwanese people, and the P1/P1, P1/P4 and P4/P4 genotype frequencies were 21.0%, 41.1% and 37.9%, respectively. The sequencing data confirmed the results of previous studies, showing that CCR5P1 exhibited a complete linkage disequilibrium with a polymorphic allele 59029A present in the CCR5 promoter. Furthermore, fluorescence-activated cell sorter analysis revealed that, in the absence of the CCR2-64I mutation, individuals carrying CCR5P1 tended to express more surface CCR5 on monocytes and CD4+ cells. Therefore, this study not only reports the frequencies for the CX3CR1 and CCR5 promoter haplotypes in a Chinese population living in Taiwan, but also identifies a statistical link between the P1/P1 haplotype and the elevated CCR5 expression levels in the study group.

Effect of insulin-like growth factor-1 and insulin-like growth factor binding protein-3 complex in cavernous nerve cryoablation

The purpose of this work was to study the effect of insulin-like growth factor 1 (IGF-1) and its binding protein (IGFBP-3) on the recovery of erectile function in a rat model for neurogenic impotence. In all, 28 male Sprague-Dawley rats were divided into four groups: seven underwent a sham operation; seven underwent bilateral cavernous nerve freezing (control group); seven underwent bilateral cavernous nerve freezing followed by intraperitoneal injection of IGF-1; and seven underwent bilateral cavernous nerve freezing followed by intraperitoneal injection of IGFBP-3. Erectile response was assessed by cavernous nerve electrostimulation at 3 months, and samples of penile tissue were evaluated histochemically for nitric oxide synthase (NOS)-containing fibers. In the sham and IGF-1 group, there were significantly higher maximal intracavernous pressures compared to the IGFBP-3 complex and the control group. Correspondingly in the cavernosum, there were significantly more NOS-containing nerve fibers in the sham and IGF-1 groups. In conclusion, administration of IGF-1 can facilitate the regeneration of NOS-containing nerve fibers in penile tissue and enhance the recovery of erectile function after bilateral cavernous nerve cryoablation. The reverse effect was noted with the IGFBP-3 complex injection.

Neurotrophic effects of vascular endothelial growth factor and neurotrophins on cultured major pelvic ganglia

OBJECTIVE

To investigate the feasibility of using a ganglial culture system to screen various growth factors as potential therapeutic agents for pelvic nerve injuries.

MATERIALS AND METHODS

The major pelvic ganglia (MPG) were isolated from male rats and attached to culture dishes with the aid of Matrigel (Becton Dickinson, Mountain View, CA, USA). Alternatively, the dorso-caudal region (DCR) of MPG, from which the cavernous nerves originate, was dissected and then attached to a Matrigel-coated coverslip. The MPG or DCR was cultured in serum-free medium supplemented with phosphate-buffered saline (PBS, control), 50 ng/mL of vascular endothelial growth factor (VEGF), 20 ng/mL of a neurotrophin (BDNF, NT3, or NT4), or combinations of these growth factors. After 2 days of incubation, the ganglial tissues with their outgrowing nerve fibres were stained for the expression of NADPH-diaphorase, tyrosine hydroxylase (TH) and acetylcholinesterase (AChE). The length and staining intensity of nerve fibres were analysed.

RESULTS

The outgrowing fibres were significantly longer in MPG treated with any of the four tested growth factors than in PBS-treated MPG. The combination of VEGF and NT3 induced the best fibre growth. Improvements to the culturing conditions allowed a histological examination of the outgrowing fibres for the expression of nitric oxide synthase (NOS), TH and AChE. VEGF and BDNF were equally capable of inducing NOS- and TH-expressing fibres. BDNF was much weaker than VEGF for inducing AChE-expressing fibres.

CONCLUSIONS

This improved culturing system is potentially useful for screening nerve-regenerating factors; VEGF had neurotrophic effects comparable with BDNF, NT3, or NT4.

The effect of vascular endothelial growth factor and brain-derived neurotrophic factor on cavernosal nerve regeneration in a nerve-crush rat model

OBJECTIVE

To test the hypothesis that an intracavernosal injection with brain-derived neurotrophin factor (BDNF) and vascular endothelial growth factor (VEGF) can facilitate nerve regeneration and recovery of erectile function after cavernosal nerve injury.

MATERIALS AND METHODS

The study included 25 Sprague-Dawley rats; four had a sham operation, seven bilateral nerve crushing with no further intervention, and 14 bilateral nerve crushing with either an immediate (seven) or delayed for 1 month (seven) intracavernosal injection with BDNF+VEGF. Erectile function was assessed by cavernosal nerve electrostimulation at 3 months, and neural regeneration by NADPH-diaphorase staining and tyrosine hydroxylase (TH) staining of penile tissue and major pelvic ganglia (MPG).

RESULTS

After nerve crushing, the functional evaluation at 3 months showed a lower mean (SD) intracavernosal pressure (ICP) with cavernosal nerve stimulation, at 33.9 (15.3) cmH2O, than in the sham group, at 107.8 (18.1) cmH2O. With an immediate injection with BDNF+VEGF the ICP was significantly higher than in the controls, at 67.8 (38.5) cmH2O. Even delayed injection with BDNF+VEGF improved the ICP, to 78.0 (21.8) cmH2O. Histological analysis of specimens stained for NADPH and TH showed a significant change in the morphology of terminal branches of the cavernosal and dorsal nerves, and the staining quality of the neurones in the MPG. The number of positively stained nerve fibres tended to revert to normal after treatment with BDNF+VEGF.

CONCLUSION

An intracavernosal injection with BDNF+VEGF appears to both prevent degeneration and facilitate regeneration of neurones containing neuronal nitric oxide synthase in the MPG, dorsal nerve and intracavernosal tissue. Therefore it might have therapeutic potential for enhancing the recovery of erectile function after radical pelvic surgery.

Aberrant caspase-activated DNase (CAD) transcripts in human hepatoma cells

The gene of caspase-activated DNase (CAD), the key enzyme for nucleosome cleavage during apoptosis, is mapped at chromosome 1p36, a region usually associated with hemizygous deletions in human cancers, particularly in hepatoma (HCC). It is tempting to speculate that CAD plays a tumour-suppressive role in hepatocarcinogenesis. To address this, we examined the CAD transcripts in six human HCC cell lines, one liver tissue from a non-HCC subject, and peripheral blood leukocytes (PBL) from three healthy individuals. Alternatively spliced CAD transcripts with fusion of exon 1 to exon 7 were isolated in most of the examined samples including HCC cells and normal controls. However, relatively abundant alternatively spliced CAD transcripts with fusion of exon 2 to exon 6 or 7, in which the corresponding domain directing CAD interaction with ICAD was preserved, were found only in poorly differentiated Mahlavu and SK-Hep1 cells. Interestingly, an abnormal CAD transcript with its exon 3 replaced by a truncated transposable Alu repeat was isolated in Hep3B cells, indicative of the implication of an Alu-mediated genomic mutation. Moreover, mis-sense mutations in the CAD genes were identified in all six HCC cell lines. Upon UV-induced apoptosis, DNA fragmentation efficiency was found to be intact, partially reduced and remarkably reduced in Huh7 and J328, Hep3B and HepG2, and Mahlavu cells, respectively. That mutations and aberrantly spliced transcripts for the CAD gene are frequently present in human HCC cells, especially in poorly differentiated HCC cells, suggests a significant role of CAD in human hepatocarcinogenesis.

Neonatal chemical sympathectomy attenuates fructose-induced hypertriglyceridemia and hypertension in rats

Experiments were performed to determine the pathogenic contribution of the peripheral sympathetic nervous system to fructose-induced hypertriglyceridemia, hyperinsulinemia and hypertension in rats. Neonatal chemical sympathectomy was performed in neonatal Sprague-Dawley rats (1-week old) by administration of guanethidine (50 microg/g, i.p.) 5 times per week for consecutive 3 weeks and nerve-intact rats were served as controls. Both groups of rats were fed a fructose-enriched diet for 9 weeks. The systolic blood pressure (SBP) and body weight were measured weekly and arterial blood samples were taken weekly for determinations of plasma insulin, glucose and triglyceride levels. The results showed that fructose feeding for one week significantly increased SBP in intact rats and sympathectomized rats (116+/-1 to 119+/-1 mmHg and 116+/-1 to 120+/-1 mmHg, respectively). SBP further increased thereafter in both groups. However, the increased SBP levels were significantly higher in intact group than in sympathectomized group after 5 weeks of fructose feeding. Fructose feeding for one week concurrently produced hypertriglyceridemia that preceded the appearance of hyperinsulinemia in both groups. The elevated plasma triglyceride levels were significantly lower in sympathectomized rats than in intact rats after 3 weeks of fructose feeding, whereas the elevated plasma insulin concentrations were not different between groups throughout fructose feeding period. Plasma glucose concentrations of both groups were comparable and remained unchanged throughout the study. These data indicate that neonatal chemical sympathectomy attenuated, but did not prevent, fructose-induced elevations in blood pressure and plasma triglyceride levels, suggesting a partial dependency of fructose-induced hypertriglyceridemia and hypertension on the integrity of the peripheral sympathetic nervous system (SNS) in rats.

Nonhepatic response to portal glucose delivery in conscious dogs

The glycemic and hormonal responses and net hepatic and nonhepatic glucose uptakes were quantified in conscious 42-h-fasted dogs during a 180-min infusion of glucose at 10 mg. kg(-1). min(-1) via a peripheral (Pe10, n = 5) or the portal (Po10, n = 6) vein. Arterial plasma insulin concentrations were not different during the glucose infusion in Pe10 and Po10 (37 +/- 6 and 43 +/- 12 microU/ml, respectively), and glucagon concentrations declined similarly throughout the two studies. Arterial blood glucose concentrations during glucose infusion were not different between groups (125 +/- 13 and 120 +/- 6 mg/dl in Pe10 and Po10, respectively). Portal glucose delivery made the hepatic glucose load significantly greater (36 +/- 3 vs. 46 +/- 5 mg. kg(-1). min(-1) in Pe10 vs. Po10, respectively, P < 0.05). Net hepatic glucose uptake (NHGU; 1.1 +/- 0. 4 vs. 3.1 +/- 0.4 mg. kg(-1). min(-1)) and fractional extraction (0. 03 +/- 0.01 vs. 0.07 +/- 0.01) were smaller (P < 0.05) in Pe10 than in Po10. Nonhepatic (primarily muscle) glucose uptake was correspondingly increased in Pe10 compared with Po10 (8.9 +/- 0.4 vs. 6.9 +/- 0.4 mg. kg(-1). min(-1), P < 0.05). Approximately one-half of the difference in NHGU between groups could be accounted for by the difference in hepatic glucose load, with the remainder attributable to the effect of the portal signal itself. Even in the absence of somatostatin and fixed hormone concentrations, the portal signal acts to alter partitioning of a glucose load among the tissues, stimulating NHGU and reducing peripheral glucose uptake.

Influence of nucleotide polymorphisms in the CCR2 gene and the CCR5 promoter on the expression of cell surface CCR5 and CXCR4

Polymorphisms in the CCR2 gene (CCR2-64I) and the CCR5 promoter (pCCR5-59029G) have been correlated with slower HIV-1 disease progression. How these polymorphisms influence the rate of AIDS progression has remained unclear. We have therefore investigated whether these nucleotide polymorphisms will reduce the expression levels of surface CCR5 and CXCR4, and thus lead to slower AIDS progression. For this, a cohort of Chinese volunteers in Taiwan was subjected to the determination of CCR2 and pCCR5 genotypes followed by analysis of the surface CCR5 and CXCR4 expression on five cell types derived from peripheral blood mononuclear cells by flow cytometry. Several significant associations were detected between genotypes and expression levels of the proteins. The most important finding was that an increased number of CD4(+) cells expressing CCR5 correlated with pCCR5-59029A homozygosity without the interference of both the CCR2-64 and the CCR5 delta 32 (deleted 32 bp) mutations (P: = 0.0453), which is consistent with the previous data on the association of the genotype to AIDS progression. Since different genetic polymorphisms co-exist in human beings, the rate of AIDS progression as well as the risk of rheumatoid arthritis may be governed by the interplay of the array of nucleotide changes and their affected proteins.

Importance of the hepatic arterial glucose level in generation of the portal signal in conscious dogs

The aim of this study was to determine whether the elimination of the hepatic arterial-portal (A-P) venous glucose gradient would alter the effects of portal glucose delivery on hepatic or peripheral glucose uptake. Three groups of 42-h-fasted conscious dogs (n = 7/group) were studied. After a 40-min basal period, somatostatin was infused peripherally along with intraportal insulin (7.2 pmol x kg(-1) x min(-1)) and glucagon (0.65 ng x kg(-1) x min(-1)). In test period 1 (90 min), glucose was infused into a peripheral vein to double the hepatic glucose load (HGL) in all groups. In test period 2 (90 min) of the control group (CONT), saline was infused intraportally; in the other two groups, glucose was infused intraportally (22.2 micromol x kg(-1) x min(-1)). In the second group (PD), saline was simultaneously infused into the hepatic artery; in the third group (PD+HAD), glucose was infused into the hepatic artery to eliminate the negative hepatic A-P glucose gradient. HGL was twofold basal in each test period. Net hepatic glucose uptake (NHGU) was 10.1 +/- 2.2 and 12.8 +/- 2.1 vs. 11.5 +/- 1.6 and 23.8 +/- 3.3* vs. 9.0 +/- 2.4 and 13.8 +/- 4.2 micromol x kg(-1) x min(-1) in the two periods of CONT, PD, and PD+HAD, respectively (* P < 0.05 vs. same test period in PD and PD+HAD). NHGU was 28.9 +/- 1.2 and 39.5 +/- 4.3 vs. 26.3 +/- 3.7 and 24.5 +/- 3.7* vs. 36.1 +/- 3.8 and 53.3 +/- 8.5 micromol x kg(-1) x min(-1) in the first and second periods of CONT, PD, and PD+HAD, respectively (* P < 0.05 vs. same test period in PD and PD+HAD). Thus the increment in NHGU and decrement in extrahepatic glucose uptake caused by the portal signal were significantly reduced by hepatic arterial glucose infusion. These results suggest that the hepatic arterial glucose level plays an important role in generation of the effect of portal glucose delivery on glucose uptake by liver and muscle.

Net hepatic gluconeogenic amino acid uptake in response to peripheral versus portal amino acid infusion in conscious dogs

These studies were conducted to determine the effect of route of gluconeogenic amino acid delivery on the hepatic uptake of the amino acids. After a sampling period with no experimental intervention (basal period), conscious dogs deprived of food for 42 h received somatostatin, intraportal infusions of insulin (3-fold basal) and glucagon (basal), and a peripheral infusion of glucose to increase the hepatic glucose load 1.5-fold basal for 240 min. A mixture of alanine, glutamate, glutamine, glycine, serine and threonine was infused intraportally at 7.6 micromol. kg(-1). min(-1) (PorAA group, n = 6) or peripherally at 8.1 micromol. kg(-1). min(-1) (PerAA, n = 6), to match the hepatic load of gluconeogenic amino acids in PorAA. During the infusion period, there were no differences in PerAA and PorAA, respectively, with regard to arterial plasma insulin (144 +/- 18 and 162 +/- 18 pmol/L), glucagon (51 +/- 8 and 47 +/- 11 ng/L), hepatic glucose load (199.8 +/- 22.2 and 210.9 +/- 16.6 micromol. kg(-1). min(-1)), net hepatic glucose uptake (2.8 +/- 2.2 and 2.2 +/- 1.7 micromol. kg(-1). min(-1)), hepatic load of amino acids (68 +/- 14 and 62 +/- 7 micromol. kg(-1). min(-1)), or net hepatic glycogen synthesis (11.1 +/- 2.2 and 8.9 +/- 2.2 micromol. kg(-1). min(-1)). The net hepatic uptake of glutamine (2.1 +/- 0.4 vs. 0.8 +/- 0.3 micromol. kg(-1). min(-1)) and the net hepatic fractional extractions of glutamine (0.11 +/- 0.02 vs. 0.05 +/- 0.02) and serine (0.41 +/- 0.03 vs. 0.34 +/- 0.02) were greater in PorAA than in PerAA (P < 0.05). We speculate that one or more of the amino acids in the mixture causes enhancement of the net hepatic uptake and fractional extraction of glutamine, and perhaps other gluconeogenic amino acids, during intraportal amino acid delivery.

The head arterial glucose level is not the reference site for generation of the portal signal in conscious dogs

Experiments were performed on twelve 42-h-fasted, conscious dogs to determine whether the head arterial glucose level is used as a reference standard for comparison with the portal glucose level in bringing about the stimulatory effect of portal glucose delivery on net hepatic glucose uptake (NHGU). Each experiment consisted of an 80-min equilibration, a 40-min control, and two 90-min test periods. After the control period, somatostatin was given along with insulin (7.2 pmol. kg(-1). min(-1); 3.5-fold increase) and glucagon (0.6 ng. kg(-1). min(-1); basal) intraportally. Glucose was infused intraportally (22.2 micromol. kg(-1). min(-1)) and peripherally as needed to double the hepatic glucose load. In one test period, glucose was infused into both vertebral and carotid arteries (HEAD(G); 22.2 +/- 0.8 micromol. kg(-1). min(-1)); in the other test period, saline was infused into the head arteries (HEAD(S)). One-half of the dogs received HEAD(G) first. When all dogs are considered, the blood arterial-portal glucose gradients (-0.52 +/- 0.07 vs. -0.49 +/- 0.03 mM) and the hepatic glucose loads (339 +/- 14 vs. 334 +/- 20 micromol. kg(-1). min(-1)) were similar in HEAD(G) and HEAD(S). NHGU was 24.1 +/- 3.8 and 25.1 +/- 4.6 micromol. kg(-1). min(-1), and nonhepatic glucose uptake was 46.1 +/- 4.2 and 48.8 +/- 7.0 micromol. kg(-1). min(-1) in HEAD(G) and HEAD(S), respectively. The head arterial glucose level is not the reference standard used for comparison with the portal glucose level in the generation of the portal signal.

Rapid reversal of the effects of the portal signal under hyperinsulinemic conditions in the conscious dog

Experiments were performed on two groups of 42-h-fasted conscious dogs (n = 6/group). Somatostatin was given peripherally with insulin (4-fold basal) and glucagon (basal) intraportally. In the first experimental period, glucose was infused peripherally to double the hepatic glucose load (HGL) in both groups. In the second experimental period, glucose (21.8 micromol. kg-1. min-1) was infused intraportally and the peripheral glucose infusion rate (PeGIR) was reduced to maintain the precreating HGL in the portal signal (PO) group, whereas saline was given intraportally in the control (CON) group and PeGIR was not changed. In the third period, the portal glucose infusion was stopped in the PO group and PeGIR was increased to sustain HGL. PeGIR was continued in the CON group. The glucose loads to the liver did not differ in the CON and PO groups. Net hepatic glucose uptake was 9.6 +/- 2.5, 11.6 +/- 2.6, and 15.5 +/- 3.2 vs. 10.8 +/- 1.8, 23.7 +/- 3.0, and 15.5 +/- 1.1 micromol. kg-1. min-1, and nonhepatic glucose uptake (non-HGU) was 29.8 +/- 1.1, 40.1 +/- 4.5, and 49.5 +/- 4.0 vs. 26.6 +/- 4.3, 23.2 +/- 4.0, and 40.4 +/- 3.1 micromol. kg-1. min-1 in the CON and PO groups during the three periods, respectively. Cessation of the portal signal shifted NHGU and non-HGU to rates similar to those evident in the CON group within 10 min. These results indicate that even under hyperinsulinemic conditions the effects of the portal signal on hepatic and peripheral glucose uptake are rapidly reversible.

Differential effect of amino acid infusion route on net hepatic glucose uptake in the dog

Concomitant portal infusion of gluconeogenic amino acids (GNGAA) and glucose significantly reduces net hepatic glucose uptake (NHGU), in comparison with NHGU during portal infusion of glucose alone. To determine whether this effect on NHGU is specific to the portal route of GNGAA delivery, somatostatin, intraportal insulin (3-fold basal) and glucagon (basal), and intraportal glucose (to increase the hepatic glucose load by approximately 50%) were infused for 240 min. GNGAA were infused peripherally into a group of dogs (PeAA), at a rate to match the hepatic GNGAA load in a group of dogs that were given the same GNGAA mixture intraportally (PoAA) at 7.6 micromol. kg-1. min-1 (9). The arterial blood glucose concentrations and hepatic glucose loads were the same in the two groups, but NHGU (-0. 9 +/- 0.2 PoAA and -2.1 +/- 0.5 mg. kg-1. min-1 in PeAA, P < 0.05) and net hepatic fractional extraction of glucose (2.6 +/- 0.7% in PoAA vs. 5.9 +/- 1.4% in PeAA, P < 0.05) differed. Neither the hepatic loads nor the net hepatic uptakes of GNGAA were significantly different in the two groups. Net hepatic glycogen synthesis was approximately 2.5-fold greater in PeAA than PoAA (P < 0.05). Intraportal, but not peripheral, amino acid infusion suppresses NHGU and net hepatic glycogen synthesis in response to intraportal glucose infusion.

Hepatic glucose uptake rapidly decreases after removal of the portal signal in conscious dogs

The aim of this study was to assess the decay of the effect of the portal signal on net hepatic glucose uptake (NHGU). Experiments were performed on five 42-h-fasted conscious dogs. After the 40-min basal period, somatostatin was given peripherally along with insulin (1.8 pmol. kg-1. min-1) and glucagon (0.65 ng. kg-1. min-1) intraportally. In the first experimental period (Pe-GLU-1; 90 min), glucose was infused into a peripheral vein to double the glucose load to the liver (HGL). In the second experimental period (Po-GLU; 90 min), glucose (20.1 micromol. kg-1. min-1) was infused intraportally and the peripheral glucose infusion was reduced to maintain the same HGL. In the third period (Pe-GLU-2; 120 min), the portal glucose infusion was stopped and the peripheral glucose infusion was increased to again sustain HGL. Arterial insulin levels (42 +/- 3, 47 +/- 3, 43 +/- 3 pmol/l) were basal and similar in the Pe-GLU-1, Po-GLU, and Pe-GLU-2 periods, respectively. Arterial glucagon levels were also basal and similar (51 +/- 3, 49 +/- 2, 46 +/- 2 ng/l) in the three experimental periods. The glucose loads to the liver were 251 +/- 11, 274 +/- 14, and 276 +/- 12 micromol. kg-1. min-1, respectively. NHGU was 6.3 +/- 2.4, 19.1 +/- 2.8, and 9.2 +/- 1.2 micromol. kg-1. min-1, and nonhepatic glucose uptake (non-HGU) was 23.6 +/- 3.0, 5.3 +/- 1.8, and 25.5 +/- 3.7 micromol. kg-1. min-1 in the three periods, respectively. Cessation of the portal signal for only 10 min shifted NHGU and non-HGU to 9.4 +/- 2.2 and 25.0 +/- 2.8 micromol. kg-1. min-1, respectively; thus the effect of the portal signal was rapidly reversed both at the liver and peripheral tissues.

Hepatic glucose disposition during concomitant portal glucose and amino acid infusions in the dog

The effect of concomitant intraportal infusion of glucose and gluconeogenic amino acids (AA) on net hepatic glucose uptake (NHGU) and glycogen synthesis was examined in 42-h-fasted dogs. After a basal period, there was a 240-min experimental period during which somatostatin was infused continuously into a peripheral vein and insulin and glucagon (at 3-fold basal and basal rates, respectively) and glucose (18.3 mumol.kg-1.min-1) were infused intraportally. One group (PoAA, n = 7) received an AA mixture intraportally at 7.6 mumol.kg-1.min-1, whereas the other group (NoAA, n = 6) did not receive AA. Arterial blood glucose concentrations and hepatic glucose loads were the same in the two groups. NHGU averaged 4.8 +/- 2.0 (PoAA) and 9.4 +/- 2.0 (NoAA) mumol.kg-1.min-1 (P < 0.05), and tracer-determined hepatic glucose uptake was 4.6 +/- 1.6 (PoAA) and 10.0 +/- 1.7 (NoAA) mumol.kg-1.min-1 (P < 0.05). AA data for PoAA and NoAA, respectively, were as follows: arterial blood concentrations, 1,578 +/- 133 vs. 1,147 +/- 86 microM (P < 0.01); hepatic loads, 56 +/- 3 vs. 32 +/- 4 mumol.kg-1.min-1 (P < 0.01); and net hepatic uptakes, 14.1 +/- 1.4 vs. 5.6 +/- 0.4 mumol.kg-1.min-1 (P < 0.01). The rate of net hepatic glycogen synthesis was 7.5 +/- 1.9 (PoAA) vs. 10.7 +/- 2.3 (NoAA) mumol.kg-1.min-1 (P = 0.1). In a net sense, intraportal gluconeogenic amino acid delivery directed glucose carbon away from the liver. Despite this, net hepatic carbon uptake was equivalent in the presence and absence of amino acid infusion.

Longitudinal image deblurring in spiral CT

PURPOSE

To assess the feasibility of digital deconvolution techniques to improve longitudinal resolution of spiral computed tomography (CT) multiplanar reformations and evaluate how technical factors in deconvolution affect longitudinal resolution, noise, and edge ringing.

MATERIALS AND METHODS

Longitudinal line spread function (LSF) of the system was estimated from longitudinal reformations of transaxial spiral CT images of a step test phantom. By using the estimated LSF, longitudinal reformations of the phantom and three clinical spiral CT studies were deconvolved by the methods of Wiener filtering and constrained iterative deconvolution. Edge ringing and image noise were quantified for Wiener filtering and constrained iterative deconvolution.

RESULTS

Longitudinal reformations were substantially deblurred and resolution improved after deconvolution. Anatomic boundaries in clinical images were more clearly delineated after restoration. The methods of Wiener deconvolution and constrained iterative deconvolution improved the sharpness of the phantom step boundary at the expense of increased edge ringing and image noise.

CONCLUSION

In longitudinal spiral CT reformations, blurring along the longitudinal axis can be reduced by Wiener filtering or constrained iterative deconvolution.

Circadian variations of atrial natriuretic peptide in normal people and its relationship to arterial blood pressure, plasma renin activity and aldosterone level

To investigate the circadian variations of plasma atrial natriuretic peptide (ANP) and its relationship to arterial blood pressure, plasma renin activity and aldosterone level, we determined 24-h blood pressure in 14 healthy volunteers. Plasma ANP concentration, renin activity and aldosterone levels were measured every 3 h by radioimmunoassay. We found no significant circadian variation of plasma ANP level (pg/ml) (daytime level, 62 +/- 24 vs. nighttime level, 57 +/- 19, P = 0.146) and plasma renin level (ng/ml/h) (1.32 +/- 0.78 vs. 1.15 +/- 0.57, P = 0.148), but there was diurnal change of blood pressure (mmHg) (systolic, 122 +/- 7 vs. 116 +/- 11, P < 0.001; diastolic, 80 +/- 11 vs. 72 +/- 11, P = 0.025) and plasma aldosterone level (pg/ml) (86 +/- 42 vs. 62 +/- 37, P < 0.001). The blood pressure and aldosterone levels reached maxima (11:00 h and 08:00 h, respectively) before that of ANP (17:00 h) and then decreased together until the nadir at 02:00 h. This might indicate that elevation of arterial blood pressure and plasma aldosterone level stimulate release of ANP under normal physiological conditions.

Enhanced renal response to intracerebroventricular angiotensins II and III in spontaneously hypertensive rats

The acute effects of intracerebroventricular (i.c.v.) administration of angiotensin III (ANG III) on blood pressure (BP) and renal function were investigated in spontaneously hypertensive rats (SHR, n = 31) and Wistar-Kyoto (WKY) normotensive rats (n = 6). ANG II was also administered to the same rats for comparison of its renal effect. BP and renal clearance responses were measured before and during ANG injections. The results showed that i.c.v. injections of 1, 5 and 50 pmol of ANG III did not significantly alter BP in SHR, but a high dose of ANG III (50 pmol) caused a vasopressor effect (7 +/- 4 mmHg) in WKY rats. There were significant increases in renal plasma flow (RPF), glomerular filtration rate (GFR), urine flow, absolute and fractional excretions of sodium and potassium, osmolar clearance and free water reabsorption rate following i.c.v. administration of ANG III in both SHR and WKY rats. However, the enhancement in renal responsiveness to ANG III was greater in SHR than in the WKY group. At 5 pmol of ANG III, the peak increases in GFR (96 +/- 23%), diuresis (316 +/- 102%) and natriuresis (712 +/- 281%) in SHR were significantly greater than those in WKY rats (40 +/- 13%, 152 +/- 89%, 229 +/- 130%, resp.). The renal effect of central ANG III was blocked by i.c.v. ANG III antagonist, [Ile7]-ANG III, but was enhanced by bestatin, an ANG III metabolic enzyme inhibitor. I.c.v. administration of ANG II at 50 pmol increased BP in both SHR and WKY rats (14 +/- 3 and 10 +/- 3 mmHg, resp.). Greater diuretic and natriuretic responses to ANG II were also noted in SHR than in WKY rats. These results indicate that central ANG III is as active as ANG II in modulating renal function. Furthermore, the enhanced renal response to i.c.v. ANGs II and III in SHR suggests a hyperactive central RAS implicated in BP and body fluid regulation in this genetic hypertensive strain.

Nifedipine-haloperidol combination in the treatment of Gilles de la Tourette's syndrome: a case study

Anecdotal case reports have been published describing the use of the calcium channel blockers verapamil and nifedipine to provide rapid and dramatic relief in refractory Gilles de la Tourette's syndrome (TS). The authors' case presentation illustrates that, although these two drugs may not always work alone, they can be successfully used in combination with other medications for treating refractory TS.

Saturation and inversion transfer studies of creatine kinase kinetics in rabbit skeletal muscle in vivo

The steady-state kinetics of the creatine kinase reaction in rabbit skeletal muscle in vivo was investigated using inversion and saturation magnetization transfer techniques. Both techniques determined the forward rate of this reaction (creatine phosphate ATP) as approximately 0.3 s-1. This corresponds to a flux of 10 mumol creatine phosphate/s/g muscle. The saturation transfer technique underestimated the reverse reaction by approximately 56%. This result is likely due to the participation of ATP in other interactions in skeletal muscle not involving creatine phosphate.

Calcium: a program in BASIC for calculating the composition of solutions with specified free concentrations of calcium, magnesium and other divalent cations

A BASIC program is presented which facilitates the formulation of biologically relevant chemical solutions containing specified free concentrations of as many as three divalent metal cations (Ca2+, Mg2+ and the choice of a third divalent cation) at any pH in the presence of as many as three ligands (EGTA, ATP and GTP). The program uses the law of mass action and the absolute stability (association) constants found in the literature to calculate the total concentration of divalent metal cation needed to achieve a desired free concentration. The user enters the pH, the concentrations of the ligands used and the desired free concentrations of the divalent cations. This program was developed for use in a wide range of biological applications, particularly the rapid design of solutions which mimic certain aspects of intracellular fluid.