[Impact of HIV and Mycobacterium tuberculosis co-infection on related mortality].

Objective: To understand the impact of HIV and Mycobacterium tuberculosis (MTB) co-infectious (HIV/MTB) on related mortality in Guangxi Zhuang Autonomous Region, provide evidence for the development of a better HIV/MTB co-infection control and prevention program. Methods: A multiple cross-systems check (MCSC) approach was used to confirm the HIV/MTB co-infection individuals on data related to treatment, follow-up, epidemiological comprehensive and Tuberculosis (TB) special report system. Social demography characteristics, incidence of TB among HIV positive individuals, HIV incidence among MTB infection persons etc., were described. We compared the mortalities and related risks between HIV/MTB co-infection and mono HIV positive individuals as well as between the HIV/MTB co-infection and mono MTB infection persons, using both the Chi Square test and the Cox's proportional hazard regression model (Cox). Results: Reported data showed that the incidence of MTB co-infection in the HIV cohort was 17.72% (2 533/14 293), while HIV incidence in the TB patients was 5.57% (2 351/42 205), respectively. The mortality of HIV/MTB co-infection in the HIV/AIDS cohort was 15.16% (384/2 533) within one-year of observation and was significantly higher than the mortality (13.63%,1 603/11 760) of mono HIV positive individuals (P<0.000 1). The percentage of the HIV/AIDS death cases was 19.33% (384/1 987) who registered and died in the 2011 calendar year were caused by MTB co-infection. Among all the HIV/MTB co-infection patients who had been identified from the HIV cohort, 60.05% (1 521/2 533) had initiated ART, 15.48% (392/2 533) had been cured for TB and 27.48% (696/2 533) had been under complete TB regimen. Among the confirmed HIV/MTB cases from the TB cohort, the cure rate of TB was 19.70% (463/2 351) and the percentage of completed TB regimen was 37.26% (876/2 351). The percentage of the individuals whose CD(4)(+) T lymphocyte cells count appeared less than 200 cell/µl was 64.13% (785/1 224), upon the HIV diagnoses were made. Compared with individuals who were under mono HIV infection, the mortality risk on HIV/MTB co-infection was 1.17 times higher during the five-year observation period, then the patients with only mono MTB infection and the mortality risk in patients with HIV/MTB co-infection was 25.68 times higher under the 12-month observation period. Conclusions: Both the incidence and mortality of HIV/MTB appeared high in Guangxi, with mortality and the risk of mortality in the HIV/MTB co-infection group significantly higher than that in both the HIV mono infection and the MTB mono infections groups. Both the rate of antiretroviral treatment coverage and the cure rate of TB treatment should be increased in no time as well as the capability of early TB case-finding among people living with HIV.

[Bibliometric analysis on research hotspots on HIV post-exposure prophylaxis related articles in the world, 2000-2017].

Objective: To analyze and reveal the distribution, research hotspots and study trend of worldwide published articles correlated with HIV/AIDS post-exposure prophylaxis (PEP), and provide information for related studies in China. Methods: CiteSpace software 5.1 was used to visualize all related papers in the web of science database published during 2000-2017. Results: The average growth rate of international PEP-related papers was 10.78%,and number of published papers in 2016 was highest (n=34), relevant research hotspots have shifted from the prevention of occupational HIV exposure to the prevention of non-occupational HIV exposure in group at high risk, such as MSM, in recent years. Clustering analysis classified research hotspots into three categories, including risk reduction through enhanced intervention, current status of global HIV PEP and German-Austrian Recommendation. Conclusions: Non-occupational HIV PEP in groups at high-risk, especially MSM, has received increasing attention in recent years, the research of PEP mainly focus on improving the awareness and use of PEP in MSM and compliance in the course of medication. In the context of severe HIV epidemic in MSM without effective control in China, PEP should be strengthened to assess and explore the risk of HIV infection in MSM to provide reference for medical personnel and related departments to implement HIV non-occupation exposure blockade and formulate PEP medication.

Research on the mechanism of HP mediated PI3K/AKT/GSK3ß pathways in gastric cancer.

OBJECTIVE: This study aimed to investigate the mechanism of Helicobacter pylori (HP) mediated PI3K/AKT/GSK3ß signal pathways in the occurrence of gastric cancer. PATIENTS AND METHODS: For this purpose, a total of 90 patients were selected; 30 were suffering from gastric cancer and gastric ulcer (observation group I), 30 were suffering from pure gastric ulcer (observation group II) and 30 were with chronic gastritis (control group), and the lesion tissues were extracted by using endoscopy. Then, rapid urease test, RT-PCR and Western blot tests were conducted to detect the positivity rate of HP infection, the expression levels of PI3K/AKT/GSK3ß mRNA and protein respectively. RESULTS: The results showed that the positivity rate of HP infection, expression level of the PI3K/AKT/GSK3ß mRNA and protein from the samples of the observation group I were significantly higher than other two groups (p-value <0.05). CONCLUSIONS: HP may mediate the PI3K/AKT/GSK3ß signal pathways in the occurrence of gastric cancer.

[An analysis of clinical features of celiac disease patients in different ethnic].

OBJECTIVE: To summarize the clinical features of different racial patients with celiac disease (CD) and analyze the disease prevalence, diagnosis and treatment in Chinese population. METHODS: All the patients were diagnosed as CD and enrolled in Beijing United Family Hospital between January 2005 and July 2015.Clinical data including nationality, age, symptoms, endoscopic and pathological findings, outcome were collected and compared in patients from different countries. RESULTS: A total of 87 patients were enrolled including 63 Caucasians, 18 Asian patients and 6 Middle East patients.The peak age of disease onset was 40-60 years old.Patients with typical symptoms such as chronic diarrhea and weight loss only accounted for 20.7%(18/87) and 9.2%(8/87) respectively.Some patients presented with nonspecific symptoms such as abdominal pain and bloating [32.2%(28/87)], even constipation [5.7%(5/87)].13.8%(12/87) patients were previously diagnosed as irritable bowel syndrome.The incidence of abdominal pain, bloating, diarrhea and constipation between Asians and Caucasians had no statistical significance (P>0.05); but the proportions of weight loss, growth retardation, iron deficiency anemia and dermatitis herpetiformis in Asian group were significantly higher than that in Caucasian group (P<0.05). IgA type of anti-gliadin antibody (AGA), endomysium antibody (EMA) and tissue transglutaminase antibody (tTGA) were dominant autoimmune antibodies in patients with CD, which accounted for 58.6%(51/87), 44.8%(39/87) and 36.8%(32/87) respectively.The endoscopy showed that the lesion of CD was mainly located in small intestine, with reducing severity from the proximal to the distal small intestine.The lesions of duodenal bulb and descending duodenum appeared more significant in Asian group.Accordingly pathological intestinal atrophy and the degree of intraepithelial lymphocytosis were more severe in Asian patients.All 87 cases took the gluten-free diet (GFD). Eighty-one cases received serological follow up and 8 with endoscopic intestinal biopsy.The celiac disease antibodies in 47 patients turned negative from 6-9 months after GFD treatment, while 34 patients turned negative from 12-18 months after GFD.All patients reported disease remission to some extent.After 1 year GFD treatment, the pathology of endoscopic intestinal biopsy in 8 patients showed significant improvement of villous atrophy and lymphocyte infiltration. CONCLUSIONS: CD patients with typical clinical manifestations are not the majority.Serological celiac disease antibodies (AGA, EMA and tTGA) have a high diagnostic value.GFD treatment is effective on majority of celiac patients.Clinical manifestations, endoscopy, intestinal pathology, and response to GFD in Chinese patients are not the same as Caucasians.Clinicians need to pay attention to the differential diagnosis.

Quality of life after surgical resection compared with radiofrequency ablation for small hepatocellular carcinomas.

BACKGROUND: Health-related quality of life (HRQL) is an important outcome measure in studies of cancer therapy. This study aimed to investigate HRQL and survival in patients with small hepatocellular carcinoma (HCC) treated with either surgical resection or percutaneous radiofrequency ablation (RFA). METHODS: Between January 2006 and June 2009, patients with newly diagnosed solitary, small (3 cm or less) HCC were invited to participate in this non-randomized prospective parallel cohort study. The Functional Assessment of Cancer Therapy-Hepatobiliary (FACT-Hep) instrument was used for assessing HRQL. HRQL and survival were compared between the two treatment groups. RESULTS: A total of 389 patients were enrolled. Questionnaires were completed fully by 99.7 per cent of invited participants (388 of 389) at baseline, 98.7 per cent (383 of 388) at 3 months, 99.0 per cent (379 of 383) at 6 months, 98.4 per cent (365 of 371) at 1 year, 96.6 per cent (336 of 348) at 2 years and 95.1 per cent (289 of 304) at 3 years. There were no significant differences in disease-free and overall survival between the two groups. Patients treated with percutaneous RFA had significantly better HRQL total scores after 3, 6, 12, 24 and 36 months than those who had surgical resection (P < 0.001, P < 0.001, P = 0.001, P = 0.003 and P = 0.025 respectively). On multivariable analysis, the presence of concomitant disease, cirrhosis and surgical resection were significant risk factors associated with a worse HRQL score after treatment. CONCLUSION: Percutaneous RFA produced better post-treatment HRQL than surgical resection for patients with solitary small (no more than 3 cm) HCC.

CHD1L is a novel independent prognostic factor for gastric cancer.

BACKGROUND: Chromodomain helicase/ATPase DNA binding protein 1-like gene (CHD1L) is involved in malignancies. However, the role of CHD1L in gastric cancer (GC) has not been elucidated. The aim of this study is to explore the clinical role of CHD1L in GC. METHODS: The gene and protein expression levels of CHD1L were detected by quantitative real-time PCR and Western blot analysis in fresh samples of GC and paired adjacent noncancerous tissue (n = 34). We evaluated the CHD1L expression by immunohistochemistry in a large number of GC patients (n = 616) and paired adjacent noncancerous tissues from December 1, 2004 to December 1, 2008. The correlations of CHD1L expression with clinicopathological features and clinical outcome were analyzed. RESULTS: The gene and protein expression levels of CHD1L were higher in fresh samples of GC than in paired adjacent noncancerous tissues as determined by quantitative real-time PCR and Western blot analysis. Immunohistochemical analysis showed that positive expression rates of CHD1L in GC and paired adjacent noncancerous tissues were 58.7 % (361/616) and 7.3 % (45/616), respectively. CHD1L positivity was significantly associated with clinical stage and distant metastasis. GC patients with positive CHD1L expression had shorter overall survival than those with negative CHD1L expression. Multivariate analysis showed that CHD1L was an independent prognostic marker for overall survival [Hazard Ratio (HR) = 5.952, 95 % confidence interval (CI) = 3.194-11.187, P = 0.0043]. CONCLUSION: These results indicated that CHD1L could serve as a prognostic marker for GC.

Clinical and mutation analysis of four Chinese families with von Hippel-Lindau disease.

OBJECTIVE: von Hippel-Lindau (VHL) disease is a hereditary tumor syndrome predisposed to the development of tumors in a variety of body organs. The major etiopathogenesis of VHL is a mutation of the VHL tumor-suppressor gene on the short arm of chromosome 3 (3p25-26). We report on the clinical and molecular features of four Chinese kindreds with VHL disease. MATERIALS AND METHODS: The VHL gene was screened for mutation using a direct DNA sequencing analysis and a multiplex ligation-dependent probe amplification (MLPA) for 44 volunteers from these four families. Any unaffected person, with germline VHL gene mutation, was required to undergo further examination, surveillance and treatment. RESULTS: The main lesions and the average diagnostic year of the 20 patients were central nervous system hemangioblastoma (60 %, 34.92 years), renal lesion (60 %, 39.08 years), pancreatic lesion (60 %, 37.67 years), adrenal pheochromocytoma (25 %, 37.8 years) and retinal hemangioblastoma (10 %, 25.5 years). Direct sequencing detected nucleotide substitutions or small deletions in three families and MLPA revealed exon 1 deletion in family A. The five asymptomatic patients were initially diagnosed by genetic analysis and verified radiologically or surgically. CONCLUSIONS: The spectrum of clinical manifestation of VHL in the mainland Chinese population is similar to the observation in Western kindreds. Genetic testing, which plays a crucial role in early diagnosis asymptomatic patients, is obviously superior to clinical informations when diagnosing VHL disease. The members of VHL disease family may benefit from pedigree study, genetic testing, periodic follow-up, early diagnosis and prompt treatment.

Potential target antigens for immunotherapy in human pancreatic cancer.

BACKGROUND: To be effective and selective, immunotherapy ideally targets specifically tumor cells and spares normal tissues. Identification of tumor specific antigens is a prerequisite to establish an effective immunotherapy. Still very little is known about the expression of tumor-related antigens in pancreatic neoplasms. Cancer Testis antigens (CT) are antigens shared by a variety of malignant tumors, but not by normal tissues with the exception of germ cells in testis. Restricted expression in neoplastic tissues and inherent immunogenic features make CT antigens ideal for use in immunotherapy. We analyzed the expression of a selected panel of nine CT antigens that have been proven to elicit an efficient immunogenic response in other malignancies. In addition we analyzed the expression of HERV-K-MEL, an immunogenic antigen of viral origin. METHODS: Pancreatic adenocarcinoma tumor samples (n=130) were obtained intraoperatively, control tissues (n=23) were collected from cadaveric donor and from patients with chronic pancreatitis. Tumor-associated antigen expression of MAGE-A1, MAGE-A3, MAGE-A4, MAGE-A10, LAGE-1, NY-ESO-1, SCP-1, SSX-2, SSX-4 and HERV-K-MEL was assessed by PCR. Sequencing of PCR products were performed to assess the expression of SSX-4 in neoplastic and normal pancreatic tissues. RESULTS: Three of 10 tested antigens were expressed in over 10% of malignant pancreatic tissue samples. SSX-4 was found positive in 30% of cases, SCP-1 in 19% and HERV-K-MEL in 23% of cases. No expression of CT antigens was found in non-malignant pancreatic tissue with the exception of SSX-4 and and SSX-2. CONCLUSIONS: Fifty two percentage of the analyzed tissues expressed at least one CT antigen. The concomitant expression of SSX-4 in both malignant and non-malignant pancreatic tissue is a new finding which may raise concerns for immunotherapy. However, HERV-K-MEL is expressed with a relatively high prevalence and may be a candidate for specific immunotherapy in a large subgroup of pancreatic cancer patients. This study advocates the analysis of patients with regard to their immunogenic profile before the onset of antigen-specific immunotherapy.

Different quantitative measures of the impact of injury deaths on the community in the Guangxi Province, China.

BACKGROUND: Injury has been identified as a major health problem in China. Different quantitative measures based on the concept of years of potential life lost have been derived for assessing the burden of injury and other diseases. However, few studies have been conducted to compare the usefulness of these measures in terms of providing practical information. This study aims to examine the utility of different measures in assessing the impact of injury to Chinese society. METHODS: This is a population-based epidemiological study utilising surveillance and fielded-gathered data. Data are obtained from the disease surveillance information system and record on each death certificate. The mortality rates, years of potential life lost (YPLL), potentially years of productive life lost (PYPLL), and the valued years of potential life lost (VYPLL) are calculated and compared for deaths due to injury and other major diseases. Data on different causes of injury were analysed in the same manner. RESULTS: In comparison to other causes of death, injury deaths had the highest annual rates of YPLL (1265.1 years/100,000 persons), PYPLL (517.8 years/100,000 persons), and VYPLL (378.6 years/100,000 persons). Premature deaths due to injury provided the only positively valued VYPLL among all major causes of death. Among the injury deaths, motor vehicle traffic-related death caused the largest YPLL (13,274 years), PYPLL (5461 years), and VYPLL (3064 years). CONCLUSION: In considering the burden of deaths to society, mortality rate only is an insufficient measure. The age, the years of overall life and expected productivity and related economic consequences have to be taken into consideration. As an indicator of the economic impact and burden of premature deaths to society, the VYPLL seems to be an advantageous utility. Injury posts the greatest public health problem to the developing economy of China.

Regulation of expression and activity of four PKC isozymes in confluent and mechanically stimulated UMR-108 osteoblastic cells.

The transcript (mRNA), protein levels, enzyme activity, and cellular localization of four protein kinase C (PKC) isozymes identified in rat osteogenic sarcoma cells (UMR-108) were studied at confluent density and during mechanical stress (cyclic stretch). Western blot analysis indicated that growth to confluent density significantly increased the protein levels of cPKC-alpha (11.6-fold), nPKC-delta (5.3-fold), and nPKC-epsilon (22.0-fold) but not aPKC-zeta. Northern blot analysis indicated a significant (2.3-fold) increase in the 10 kb transcript of cPKC-alpha, a slight (1.3-fold) increase in that of nPKC-epsilon but no detectable change in that of the remaining isozymes. Enzyme activity assays of the individually immunoprecipitated isozymes yielded detectable kinase activity only for PKC-alpha, PKC-delta, and PKC-epsilon and only in confluent cells, corroborating the selective increase of these isozymes at confluent density. The UMR-108 cells showed a dramatic orientation response to mechanical stress with cell reshaping and alignment of the cell long axis perpendicular to the axis of force, remodeling of the actin cytoskeleton, and the appearance of multiple peripheral sites which stained for actin, vinculin, and PKC in separate experiments. Longer term mechanical stress beyond 24 h, however, resulted in no significant change in the mRNA level, protein level, or enzyme activity of any of the four PKC isozymes investigated. The results indicate that there are isozyme-selective increases in the protein levels of PKC isozymes of osteoblastic UMR-108 cells upon growth to confluence which may be regulated at the transcriptional or the post-transcriptional level. The results from UMR-108 cells support the earlier proposal (Carvalho RS, Scott JE, Suga DM, Yen EH. 1994. J Bone Miner Res 9(7):999-1011) that PKC could be involved in the early phase of mechanotransduction in osteoblasts through the activation of focal adhesion assembly/disassembly and the remodeling of the actin cytoskeleton.

Lymphogenous cyst-vein shunt in the management of chylothorax and chylorrhea.

A 36 year-old woman developed marked lymphedema and chylous cysts of the lower abdominal wall, groin, labia, accompanied by chylorrhea. After cyst excision and transplantation of the greater omentum, a left chylothorax occurred. After thoracic duct ligation and left pleurodesis, pleural effusion recurred and worsened. Lymphangioscintigraphy and conventional lymphography suggested that undrained enlarged retroperitoneal lymphatics in the right iliac fossa had disrupted and lymph had leaked into the left chest from the right iliac fossa. Treatment by a lymphatic cyst-vein anastomosis redirected excess chylous lymph into the blood circulation and chylothorax initially remitted. Several years later with recurrence of chylorrhea, the anastomosis was found to be occluded. After a second operative connection between a lymphogenous cyst and the greater saphenous vein, chylorrhea subsided and chylothorax has remitted for more than 4 years.

The tricornered gene, which is required for the integrity of epidermal cell extensions, encodes the Drosophila nuclear DBF2-related kinase.

During their differentiation epidermal cells of Drosophila form a rich variety of polarized structures. These include the epidermal hairs that decorate much of the adult cuticular surface, the shafts of the bristle sense organs, the lateral extensions of the arista, and the larval denticles. These cuticular structures are produced by cytoskeletal-mediated outgrowths of epidermal cells. Mutations in the tricornered gene result in the splitting or branching of all of these structures. Thus, tricornered function appears to be important for maintaining the integrity of the outgrowths. tricornered mutations however do not have major effects on the growth or shape of these cellular extensions. Inhibiting actin polymerization in differentiating cells by cytochalasin D or latrunculin A treatment also induces the splitting of hairs and bristles, suggesting that the actin cytoskeleton might be a target of tricornered. However, the drugs also result in short, fat, and occasionally malformed hairs and bristles. The data suggest that the function of the actin cytoskeleton is important for maintaining the integrity of cellular extensions as well as their growth and shape. Thus, if tricornered causes the splitting of cellular extensions by interacting with the actin cytoskeleton it likely does so in a subtle way. Consistent with this possibility we found that a weak tricornered mutant is hypersensitive to cytochalasin D. We have cloned the tricornered gene and found that it encodes the Drosophila NDR kinase. This is a conserved ser/thr protein kinase found in Caenorhabditis elegans and humans that is related to a number of kinases that have been found to be important in controlling cell structure and proliferation.

Short-term exposure to homocysteine depresses rat aortic contractility by an endothelium-dependent mechanism.

The effect of short-term exposure to homocysteine (Hcy) on the contractile characteristics of rat aortic tissue was assessed both in vitro and in vivo. The contractile response of Hcy-treated aortic rings in culture for 1 or 4 days was unchanged from control responses. By comparison, aortic rings from animals injected with Hcy showed marked attenuation of response compared with controls injected with saline, cysteine or methionine. The contractile response to K+ was decreased within 24 hours of Hcy injection, whereas the response to both K+ (-27%) and noradrenaline (-56%) was significantly decreased by 4 days. In contrast, the contractile response to phorbol-12,13-dibutyrate was not different between Hcy and control groups. Intimal rubbing completely restored the responsiveness of Hcy-treated tissue to K+ and noradrenaline. By comparison, L-NAME only partially restored contractile responsiveness, while the cyclooxygenase inhibitor indomethacin had no effect on contractile attenuation induced by Hcy. Western blot analysis showed a 2-fold increase of endothelial nitric oxide synthase (eNOS) and a 3-fold increase in inducible nitric oxide synthase (iNOS) protein expression in the aortic endothelial cells from Hcy-injected rats. The results indicate an early detectable effect of Hcy on the in vivo contractile properties of vascular smooth muscle. The effect is endothelium-mediated and may vary depending on the agonist studied. The mechanism is uncertain but appears to involve increased nitric oxide (NO) production. Finally, the data suggest that attenuation of contraction may not be due to a direct effect of Hcy but that the compound is modified or acts indirectly in vivo.

Remodeling of the actin cytoskeleton in the contracting A7r5 smooth muscle cell.

It has been proposed that the reorganization of components of the actin cytomatrix could contribute to force development and the low energy cost of sustained contraction in contractile cells which lack a structured sarcomere (A.S. Battistella-Patterson, S. Wang and G.L. Wright (1997) Can J Physiol Pharmacol 75: 1287-1299). However, there has been no direct evidence of an apropos actin reorganization specifically linked to the contractile response in cells of this type. Remodeling of the alpha- and beta-actin domains was studied in A7r5 smooth muscle cells during phorbol 12,13 dibutyrate (PDB)-induced contraction using immunohistologic staining and beta-actin-green fluorescent protein (beta-actin-GFP) fusion protein expression. Cell stained with phalloidin as well as cells expressing beta-actin-GFP showed densely packed actin stress cables, arranged in parallel and extending across the cell body. PDB caused approximately 85% of cells to contract with evidence of forcible detachment from peripheral adhesion sites seen in many cells. The contraction of the cell body was not uniform but occurred along a principal axis parallel to the system of densely packed beta-actin cables. During the interval of contraction, the beta-actin cables shortened without evidence of disassembly or new cable formation. The use of cytochalasin to inhibit actin polymerization resulted in the dissolution of the actin cables at the central region of the cell and caused the elongation of precontracted cells. In unstimulated cells, alpha-actin formed cables similar in arrangement to the cell spanning beta-actin cables. Within a short interval after PDB addition; however, the majority of alpha-actin cables disassembled and reformed into intensely fluorescing column-like structures extending vertically from the cell base at the center of clusters of alpha-actin filaments. The alpha-actin columns of contracting cells showed strong colocalization of alpha-actinin suggesting they could be structurally analogous to the dense bodies of highly differentiated smooth muscle cells. The results indicate that the alpha- and beta-actin domains of A7r5 cells undergo a highly structured reorganization during PDB-induced contraction. The extent and nature of this restructuring suggest that remodeling could play a role in contractile function.

[Recovery of gastrointestinal motility following laparoscopic versus open cholecystectomy].

OBJECTIVE: To investigate the recovery of gastrointestinal motility after laparoscopic cholecystectomy (LC) and open cholecystectomy (OC). METHODS: Motilin (MOT), gastrin (GAS), electrogastrogram (EGG), the peristaltic sound recovery timing (PSRT) and the anorectum exhaust timing (AET) were determined in 30 patients having LC and 18 patients having OC. RESULTS: MOT, GAS, EGG frequency and EGG amplitude on the first, second and third day after operation in LC group were not significantly different in comparison with preoperative data (P > 0.05), but significant difference on the first and second postoperative day compared with preoperative data and data of the the LC group (P < 0.05). The PSRT and AET in the LC group were much shorter in comparison with the OC group (P < 0.05). CONCLUSIONS: The recovery of gastrointestinal motility after LC is earlier than OC, which justifies early feeding for patients after LC.

Hepatic uptake of bromosulfophthalein-glutathione in perfused Eisai hyperbilirubinemic mutant rat liver: a multiple-indicator dilution study.

The hepatocellular uptake of the glutathione conjugate of bromosulfophthalein (BSPGSH) was examined in Eisai hyperbilirubinemic rats (EHBR; originating from Sprague-Dawley rats), which lacked the ATP-dependent canalicular transport for non-bile acid organic anions, a trend common to other mutant rat strains (TR- and GY, originating from Wistar rats). Single-pass perfused rat liver experiments were conducted with BSPGSH (26-257 microM) using the multiple indicator dilution technique. The steady-state extraction ratio of BSPGSH was close to zero due to lack of biliary excretion. After the introduction of a bolus dose containing vascular (51Cr-labeled red blood cells), interstitial (125I-labeled albumin and [14C]sucrose) and cellular space (D2O) indicators and [3H]BSPGSH into the portal vein, the outflow dilution profile of [3H]BSPGSH was found to display a protracted declining profile (tailing) at low input BSPGSH concentrations; the tail disappeared at higher BSPGSH concentrations. When data were fitted with the barrier-limited model of Goresky as used previously for BSPGSH for the Sprague-Dawley rat (SDR), model fitting was found to evoke an additional "deep pool" within the hepatocyte to account for the "tail" component. The deep pool became evident for the EHBR because biliary excretion of BSPGSH was absent and the rate of return from the deep pool was slow. The concentration of BSPGSH within the deep pool was estimated to be 12 +/- 8 times that in the cytosol. The binding of BSPGSH to EHBR S9 (effective binding concentration of 53 microM and a binding association constant KA of 2.4 x 10(4) M-1), however, was found to be lower than that of SDR S9 and could not account for the late-in-time data. The influx permeability-surface area product was concentration dependent and decreased from 0.27 to 0.01 ml.sec-1.g-1 with increasing BSPGSH concentration; the throughput component, or the portion of the dose that goes through the liver without entering the hepatocyte, increased with increasing concentration. The trends were characteristic of carrier-mediated transport and were similar to those found for the uptake of BSPGSH in SDR.

Carrier-mediated uptake and excretion of bromosulfophthalein-glutathione in perfused rat liver: a multiple indicator dilution study.

The hepatic removal of the glutathione conjugate of bromosulfophthalein (BSPGSH) was studied in the single-pass perfused rat liver with the multiple indicator dilution (MID) technique against various background concentrations of BSPGSH (20 to 214 mumol/L) over which nonlinear binding to both plasma (albumin) and tissue proteins with two classes of binding sites was found. A bolus containing 51Cr-labeled red blood cell (a vascular reference), [125I]albumin and [14C]sucrose (large and small molecular weight interstitial references, respectively), D2O (a cellular space reference), and [3H]BSPGSH was injected into the portal vein during steady-state. The eliminated fraction of dose, obtained by subtracting the survival fraction of [3H]BSPGSH in plasma from one, corresponded to the steady state extraction ratio (E) with bulk data, which declined from 0.74 +/- 0.04 to 0.27 +/- 0.01 with concentration. The major portion of the tracer outflow profile was a throughput component, which is the proportion of tracer that did not enter liver cells during its transit through the liver. The influx, efflux, and sequestration coefficients, evaluated with previously developed barrier-limited models, provided the corresponding influx (k1), efflux (k-1) and excretion (kseq) rate constants. Concentration-dependent influx (Vmax = 83 nmol min-1 g-1 and Km = 3.7 mumol/L), efflux (Vmax = 15 nmol min-1 g-1 and Km = 1.8 mumol/L), and excretion (Vmax = 94 nmol min-1 g-1 and Km = 1.8 mumol/L) were obtained for BSPGSH, when Km values are expressed in terms of the unbound concentrations. In these calculations, the observed unbound tissue concentration was not used for estimation of the Vmax and Km for efflux and excretion because of overestimation, because of the presence of highly concentrated BSPGSH in ductular elements present in liver homogenates; rather, the unbound tissue concentration was calculated from the influx, efflux, and removal rate coefficients. Because of carrier-mediated entry, the unbound tissue concentration does not equal the unbound plasma concentration, and kinetic parameters for BSPGSH excretion could be alternately estimated when the rate of excretion or net rate of loss of BSPGSH from plasma was regressed against the estimated tissue unbound concentration. This yielded a Vmax of 97 nmol min-1 g-1 and a Km of 3.6 mumol/L, values similar to those obtained from MID.(ABSTRACT TRUNCATED AT 400 WORDS)