Arginine-nitric oxide pathway in plasma membrane of rat hepatocytes during early and late sepsis

OBJECTIVE

To study the transported L-arginine in rat hepatocytes during different stages of sepsis.

DESIGN

A prospective, controlled study.

SUBJECTS

Thirty-six Sprague-Dawley male rats (250 to 300 g) were anesthetized and studied.

INTERVENTIONS

Early sepsis was produced 9 hrs after cecal ligation and puncture (CLP) and late sepsis developed 18 hrs after CLP. The control group underwent sham operation. Plasma membrane of rat hepatocytes was prepared by differential centrifugation. The [3H] L-arginine uptake of plasma membrane vesicles during sepsis was measured and inhibition studies employing omega-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine were performed.

MEASUREMENTS AND MAIN RESULTS

L-arginine transport was saturable, increased linearly with plasma membrane protein concentration, and increased with uptake time up to 5 mins. [3H] L-arginine uptake increased by 77% to 121% (p < .05) during early sepsis, with no significant changes during late sepsis. Comparing inhibitors of nitric oxide synthase, L-NAME was effective in inhibiting L-arginine transport while aminoguanidine was not.

CONCLUSIONS

L-arginine transport was enhanced in rat hepatocytes during the early stage of sepsis. The increased uptake of L-arginine could contribute to the increase production of nitric oxide by hepatocyte during sepsis.

Prognostic factors in node-negative breast cancer patients: the experience in Taiwan

BACKGROUND

Adjuvant chemotherapy has improved the length of disease-free survival and overall survival in node-negative breast cancer patients. It has been a common practice to select only the patients with higher rates of recurrence for adjuvant therapy. Therefore, it is essential to define the risk factors in node-negative breast cancer patients.

MATERIALS AND METHODS

Two hundred fifty-five patients with axillary node-negative breast cancers without adjuvant chemotherapy or hormonal therapy at Chang Gung Memorial Hospital between 1981 and 1986 were included in this study. Tissue blocks for DNA flow cytometry study was available in the tumors of 145 patients.

RESULTS

The median follow-up period was 121 months and the percentages of patients with 10 years of disease-free survival (DFS) and overall survival (OS) were 75.1% and 82.2%, respectively. The significant poor prognostic factors for 10 years of OS were a tumor size larger than 3 cm, negative estrogen and progesterone receptor status, and having a non-diploid tumor (p value = 0.0176, 0.048 and 0.016, respectively). The patients with frozen section, high mitotic rate, and Scarff-Blood-Richardson (SBR) grade II and III tumors had a worse prognosis than the others, but this trend did not reach statistical significance. The patients with positive estrogen receptor status had a 10-year disease-free rate (DFR) of 94%, and these with tumors less than 2 cm plus SBR grade I had a 10-year DFR of 92%.

CONCLUSION

The node-negative breast cancer patients with a low risk of recurrence were those who had estrogen receptor positive, tumor less than 2 cm with SBR grade I, and intraductal carcinomas. Adjuvant chemotherapy would be no benefit for these patients.

Multiple-pulse mixing sequences that selectively enhance chemical exchange or cross-relaxation peaks in high-resolution NMR spectra

Rotating-frame NMR experiments which either emphasize or suppress cross relaxation, and which simultaneously suppress TOCSY, COSY, and zero-quantum peaks in NMR spectra, are presented and analyzed. The new experiments rely on mixing sequences which follow naturally from the transverse-ROESY (Tr-ROESY) sequence of Hwang and Shaka, and which are applicable to larger molecules in solution (spin diffusion limit). In the first variant a modified Tr-ROESY sequence, called multiple-pulse ROESY (MP-ROESY), is used to enhance cross-relaxation peak intensity compared to Tr-ROESY; in the second, called phase-modulated CLEAN chemical exchange (CLEANEX-PM), cross-relaxation peaks are greatly attenuated. The two methods are thus complementary: MP-ROESY is used to observe Overhauser peaks, and CLEANEX-PM is used to eliminate them, permitting clear observation of chemical exchange peaks alone. The new techniques are examined by theory and experiment. Practical guidelines that will result in high-quality spectra are given, including the judicious use of continuous weak static magnetic field gradients.

Comparison of two soluble guanylyl cyclase inhibitors, methylene blue and ODQ, on sodium nitroprusside-induced relaxation in guinea-pig trachea

To clarify further the role of cyclic GMP in mediating the relaxant response in guinea-pig trachea induced by sodium nitroprusside (SNP), the effects of soluble guanylyl cyclase inhibitors, methylene blue and 1H-[1,2,4]oxadiazolo[4,3,-a]quinoxalin-1-one (ODQ) on SNP-induced muscle relaxation and cyclic GMP accumulation were determined. SNP (0.3-100 microM) evoked a concentration-dependent relaxation of guinea-pig isolated tracheas precontracted with 0.3 microM carbachol. Preincubation of the preparations with methylene blue (10, 30 and 100 microM) resulted in a slight but concentration-dependent prevention of the relaxant response to SNP. In contrast, the relaxation to SNP was extensively prevented by 3 microM ODQ and almost abolished by 10 microM ODQ. SNP (30 microM) induced a significant elevation of cyclic GMP accumulation (from 1.34+/-0.14 to 5.39+/-0.28 pmol mg(-1) protein, n= 5; P<0.001), which was partially attenuated by 100 microM methylene blue (3.11+/-0.51 pmol mg(-1) protein, n=5; P<0.05), whereas completely abolished by 10 microM ODQ (1.31+/-0.28 pmol mg(-1) protein, n = 5; P<0.001). Methylene blue, but not ODQ and Nomega-nitro-L-arginine methyl ester (L-NAME), caused a concentration-dependent contraction in the tracheal preparation. The tension produced by 100 microM methylene blue was 41.8+/-4.3% (0.3 microM carbachol as 100%; n = 12). Moreover, the non-selective muscarinic receptor antagonist atropine and the M3-selective antagonist 4-diphenylacetoxy-N-methylpiperidine methiodine greatly inhibited the contractile effect evoked by methylene blue (100 microM). In conclusion, this study provides substantial evidence that SNP-induced muscle relaxation in guinea-pig trachea is completely via a cyclic GMP-dependent mechanism. Furthermore, ODQ, but not methylene blue, will likely become an important tool in differentiating between cyclic GMP-dependent and -independent effects of nitric oxide.

Hepatocellular carcinoma complicated with coexisting hepatolithiasis: pitfalls in diagnosis and management

Nineteen patients with hepatocellular carcinoma associated with hepatolithiasis were retrospectively analyzed. Eleven of the 19 patients presented with hepatolithiasis-related biliary infection. Diagnosis was erroneously assumed to be hepatolithiasis alone, liver abscess, or cholangiocarcinoma in five of 11 patients before surgery was attempted. Middle-age, male sex, liver cirrhosis, hepatitis B or C infection, abnormal alpha-fetoprotein, and negative carcinoembryonic antigen raised the suspicion of associated hepatocellular carcinoma rather than cholangiocarcinoma in patients with hepatolithiasis. Antibiotics and nonoperative methods to resolve biliary infection first, followed by hepatectomy, in selected cases, to eradicate hepatocellular carcinoma and hepatolithiasis simultaneously provides the best chance for long-term survival. Otherwise, patients often died of hepatolithiasis-related biliary sepsis rather than hepatocellular carcinoma per se in the long run.

Clinical analysis of inflammatory masses of the pancreatic head region

BACKGROUND/AIMS

Inflammatory masses of the pancreatic head are a dilemma for surgeons, especially when the differences between these lesions and pancreatic head carcinoma are not so clear. The surgical management of these inflammatory benign lesions is also a topic with conflicting opinions. A clinical analysis was performed in an attempt to differentiate between these lesions and malignancy. The results of our observatory strategy of these lesions are also presented.

METHODOLOGY

From 1992 to 1994, 73 patients with ultrasonographically (US) or computed tomographically (CT) heterogenous pancreatic head lesions were diagnosed at the Department of Surgery, Chang Gung Memorial Hospital, Taipei, Taiwan. Forty-nine of these lesions were neoplastic (Group I), but the remaining 24 patients had inflammatory non-neoplastic lesions (pancreatic inflammatory masses, IPM, Group II), which were diagnosed during laparotomy by core needle biopsy. Surgery and outcome were reviewed. Ten of the 24 patients in group II received biopsy only, and the remaining 14 patients received bypass procedures. At follow-up of at least 16 months of the surviving patients (n=21), only 9.5% were with residual lesions. All cases in group II revealed shrinkage of masses. We focused on the clinical features, hematology, biochemistry, image study, serum CEA and CA 19-9, and compared these variances between the 2 groups.

RESULTS

Three clinical features were statistically different between groups I and II: mean age at presentation of disease (group I vs II = 53.3 vs 65.1), the tendency of a past history of alcoholism (Group II), and presence of abdominal pain (Group II). Group II also showed a higher level of serum alkaline phosphatase and a lower level of total bilirubin as well as a lower level of CA19-9. These inflammatory masses could not be distinguished from the true neoplasms pre-operatively on endoscopic appearance, US, or CT.

CONCLUSIONS

Pre-operative differentiation between these pancreatic lesions may be difficult but laparotomy and core needle biopsy remain safe and reliable procedures. Our short-term follow-up justified the bypass surgery and that observatory strategy is enough for those patients with pancreatic head inflammatory masses.

Cell proliferation in human prostatic smooth muscle cells involves the modulation of protein kinase C isozymes

We have examined the role of protein kinase C in the regulation of foetal-calf serum-stimulated cell proliferation in human prostatic smooth muscle cells. The data showed that the proliferative effect to foetal-calf serum (10%, v/v) was partially inhibited by 12-(2-cyanoethyl)-6,7,12,13-tetrahydro-13-methyl-5-oxo-5H-indolo (2,3-a) pyrrolo (3,4-c)-carbazole (Go-6976), a selective Ca2+-dependent protein kinase C inhibitor, suggesting that Ca2+-dependent protein kinase C isozymes might play roles in this proliferative regulation. Additionally, foetal-calf serum caused a significant translocation of protein kinase C-betaII and -epsilon from a cytosolic to a membrane distribution. These findings combined with the aforementioned functional experiments suggest that foetal-calf serum-stimulated cell proliferation might involve the activation of protein kinase C-betaII in human prostatic smooth muscle cells; however, the role of protein kinase C-epsilon in mediating cellular functions other than cell proliferation remains further investigation in these cells.

Leukocyte-endothelial adherence correlates with pancreatic nitric oxide production in early cerulein-induced pancreatitis in rats

The role of nitric oxide (NO) in microcirculation during the development of acute pancreatitis was not clear. An in vivo microscopic technique was used for evaluating leukocyte-endothelial adherence in the pancreatic microcirculation after induction (cerulein) of acute pancreatitis. Microdialysis was performed to detect pancreatic nitrate concentration (NO level) by high-performance liquid chromatography. Cerulein caused significantly reduced flow velocity in 1 h (31 %) and increased the number of sticking leukocytes in 2 h; both persisted for at least 3 h. Pancreatic NO level was found to be significantly elevated (2.5-fold) in 1 h and also persisted for 3 h. Both microcirculatory changes and NO elevation were significantly alleviated in cerulein-induced animals pretreated with NO synthase inhibitor (NG-nitro-L-arginine), indicating that elevation of NO could precede and account for a major portion of the observed microcirculatory changes. Furthermore, there was a strong positive correlation between numbers of adherent leukocytes and pancreatic NO level, suggesting that during the development of acute pancreatitis, NO could play an adverse role in microcirculation.

An epidemic of presumed Acanthamoeba keratitis that followed regional flooding. Results of a case-control investigation

OBJECTIVES

To investigate an outbreak of presumed Acanthamoeba keratitis (AK), to identify risk factors associated with its development, and to characterize the changing epidemiology of AK.

METHODS

We performed a pairwise-matched case-control study involving 31 patients who were diagnosed as having AK between July 1993 and December 1994. Risk factors were identified using conditional logistic regression analysis. To investigate the impact of regional flooding, we stratified counties within Iowa by whether their water facilities were affected and then calculated population-based estimates of the incidence of AK.

RESULTS

During the study, 43 presumed incident cases of AK were diagnosed; 31 were included in the case-control study. Cases were diagnosed based on the clinical presentation of keratitis, positive tandem scanning confocal microscopy examination results, and confirmatory cytopathologic findings. There were no positive culture specimens. On average, cases had symptoms for 8 weeks before diagnosis, most notably photophobia (94%), red eyes (94%), and pain (80%). Contact lens use (odds ratio [OR] = 44.16; P = .02) and fishing (OR = 22.62; P = .04) were independent predictors of the development of AK. The presence of a humidifier in the home (OR = 0.08; P = .03) and having household water that originated from a private well instead of the municipal water supply (OR = 0.12; P = .08) were protective. Twenty-nine of 30 cases resided in counties in which the water supplies were affected by flooding as determined by the Department of Natural Resources, Des Moines, Iowa. The incidence of AK in these counties was more than 10 times higher than that in the unaffected counties (relative risk = 10.83, 95% confidence interval, 1.48-79.49; P < .003).

CONCLUSIONS

We describe an epidemic of keratitis that, based on clinicopathologic and epidemiological evidence, is consistent with AK. As in previous outbreaks of culture-proven AK, contact lens use was the major risk factor. Both the results of the case-control study and the population-based incidence estimates suggest that the recent outbreak may be caused, in part, by the effects of regional flooding. However, because the outbreak also coincided with a change in diagnostic techniques, we cannot eliminate recognition bias as the reason for the apparently changing epidemiology.

Fast broadband inversion by adiabatic pulses

Despite the advantages of compensation for resonance offset and B1 inhomogeneity, adiabatic pulses are not yet in general use in high-resolution NMR, often because of the conception that these pulses require longer time or increased power to perform. We show that adiabatic pulses with tangential frequency sweeps and other frequency-modulation functions can be optimized to accomplish 13C and 1H broadband inversion using pulse lengths of 192 and 64 micro(s), respectively, at B1 strengths available with modern high-resolution probes.

Concurrent primary carcinoma of the gallbladder and acute cholecystitis

BACKGROUND/AIMS

Primary carcinoma of the gallbladder is rare and associated with a late diagnosis and poor prognosis. Concurrent acute cholecystitis frequently obscures the presence of carcinoma. The information regarding gallbladder carcinoma with acute cholecystitis is limited. In order to better understand the presentation of gallbladder carcinoma with acute cholecystitis, we retrospectively reviewed the data of patients with primary carcinoma of the gallbladder.

METHODOLOGY

The data of 86 patients with primary carcinoma of the gallbladder treated between 1979 and 1994 were compiled and reviewed. The patients were divided into 2 groups: Group 1 (with acute cholecystitis, 21 patients) and Group 2 (without cholecystitis, 65 patients). Clinicopathological comparisons were made and evaluated between these two groups

RESULTS

The average age of Group 1 patients was older than that of Group 2 patients (75+/-2 years vs. 63+/-2 years; p<0.05). Three Group 1 patients presented with sepsis. The interval between the onset of symptoms and hospital admission in Group 2 patients was significantly (p<0.05) longer than that in Group 1 patients (243+/-95 days vs. 20+/-11 days). Leukocytosis (>11,000/mm3) was more common in Group 1 patients than in Group 2 patients (47.6% vs. 15.4%). Jaundice was more common in Group 2, and fever was common in Group 1. The majority of Group 2 gallbladder cancers were stage V (75.4%). In contrast, 52.4% of Group 1 gallbladder cancers were stage III and 38.1% were stage V. The 30-day postoperative mortality rate in Group 1 and Group 2 patients was 9.5% and 7.7%, respectively. The cumulative survival of Group 1 patients was not different from that of Group 2 patients (log-rank test, p>0.05).

CONCLUSIONS

Age, the interval of symptoms prior to admission, the location of abdominal pain, fever, leukocytosis, and the absence of jaundice suggested the presence of acute cholecystitis in gallbladder carcinoma. A high index of suspicion of the disease, intraoperative examination of gallbladder specimens, and more aggressive surgical treatment may improve patient survival.

The dynamics of disease progression in sepsis: Markov modeling describing the natural history and the likely impact of effective antisepsis agents

We conducted a 9-month prospective cohort study of 2,527 patients with systemic inflammatory response syndrome in three intensive care units and three general wards in a tertiary health care institution. Markov models were developed to predict the probability of movement to and from more severe stages--sepsis, severe sepsis, or septic shock--at 1, 3, and 7 days. For patients with sepsis, severe sepsis, and septic shock, the probabilities of remaining in the same category after 1 day were .65, .68, and .61, respectively. The probability for progression after 1 day was .09 for sepsis to severe sepsis and .026 for severe sepsis to shock. The probability of patients with sepsis, severe sepsis, and septic shock dying after 1 day was .005, .009, and .079, respectively. The model can be used to predict the reduction in end organ dysfunction and mortality with use of increasingly effective antisepsis agents.

Helicobacter pylori in surgical specimens from patients with resectable gastric adenocarcinoma

BACKGROUND

To investigate the prevalence of Helicobacter pylori (H. pylori) in surgical specimens from patients with respectable gastric adenocarcinoma using a histological method, and to study the specific biology of H. pylori-associated gastric cancer.

MATERIALS AND METHODS

The presence of H. pylori in resected specimens from 276 patients treated between October 1994 and October 1996 was evaluated histologically using hematoxylin-eosin stain. Clinicopathologic data, including age, gender, cancer location, invasion depth, histologic type (intestinal or diffuse), stage (early or advanced), and the histology of the noncancerous gastric mucosa, were compared between patients testing positive and those testing negative for H. pylori.

RESULTS

The overall positive rate of H. pylori was 27.5%. H. pylori-positive gastric cancer was frequently associated with atrophic gastritis or intestinal metaplasia in the noncancerous tissue, but was not associated with other variables.

CONCLUSION

The results contradict the prevailing concept that H. pylori rarely colonizes in the metaplastic mucosa. To determine whether patients who have normal mucosa with superficial gastritis have a lower seroprevalence of H. pylori, further serologic study of the IgG antibody against H. pylori is mandatory. Our histologically positive rate is relatively lower than the seropositive one. More tissue samplings and special stains may provide more precise results.

Hepatocellular carcinoma presenting as pyogenic liver abscess: characteristics, diagnosis, and management

We performed a 17-year retrospective analysis of 10 cases of hepatocellular carcinoma presenting as pyogenic liver abscess. Spontaneous tumor necrosis and biliary obstruction caused by tumor thrombi, superimposed with bacterial infection, were the two major pathogeneses. Exact diagnosis of the underlying hepatocellular carcinoma was made for five of the 10 patients before management was attempted. Main clinical manifestations included fever, chills, right-upper-quadrant pain, malaise, anorexia, jaundice, and hepatomegaly. Characteristics such as middle age and male sex, seropositivity for hepatitis B and/or hepatitis C, chronic liver disease, unexplained anemia, marked weight loss, and a severely inversed albumin/globulin ratio raise suspicions about the underlying hepatocellular carcinoma. Management strategies included percutaneous drainage (n = 3), surgical drainage (n = 4), and hepatectomy (n = 3) in addition to administration of parenteral antibiotics in all cases. The prognosis was dismal, with a mean survival of 3.5 months (range, 8 days to 6 months).

Antiproliferative effect in human prostatic smooth muscle cells by nitric oxide donor

We obtained a primary culture of prostatic cells through explantation from patients with benign prostatic hyperplasia. Structural morphology, immunohistochemical staining, and growth characteristics of these cells demonstrate that they are consistent with the population of smooth muscle cells (SMCs). We examined the influence of a nitric oxide donor, sodium nitroprusside (SNP), on the regulation of human prostatic SMC proliferation. SNP exhibited a concentration-dependent (0.1-10 microM) inhibition of fetal calf serum-induced proliferation in human prostatic SMCs. In addition, growth-inhibitory responses to 8-bromo-cGMP (1-30 muM) were observed. However, the responses to SNP were significantly diminished by the presence of 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (3 microM; a selective guanylate cyclase inhibitor). Furthermore, SNP induced an increased concentration-dependent accumulation of intracellular cGMP in human prostatic SMCs. After 48-hr period of deprivation of serum, cells were restimulated with serum to permit cell cycle progression. The addition of SNP (10 microM) at various times after the addition of serum to serum-deprived cells showed maximal inhibition of cell proliferation even when added 6 hr after the serum. This blocking effect of cell cycle progression was lost gradually as the delay from serum to SNP application increased from 6 to 18 hr. The membrane-associated protein kinase C (PKC) activity was studied in human prostatic SMCs; results showed that fetal calf serum (10%, v/v) significantly increased membrane-associated PKC activity. SNP (10 muM), which had little effect on basal kinase activity, completely abolished serum-induced augmentation of PKC activity. Therefore, we suggest that SNP mediates its antiproliferative effect by the inhibition of PKC activity on human prostatic SMCs; furthermore, its antiproliferative effect occurs at the early G1 phase of the cell cycle.

Pyogenic liver abscesses in patients with malignant disease: a report of 52 cases treated at a single institution

BACKGROUND

Prognosis of pyogenic liver abscesses in patients with malignant disease is generally considered poor. The discrepancy between the outcomes of liver abscesses caused by hepatopancreatobiliary malignant disease and those caused by other malignant diseases, however, to our knowledge has never been investigated.

OBJECTIVES

To clarify the clinical course of pyogenic liver abscess in patients with different types of cancer, and to compare outcomes in abscesses caused by hepatopancreatobiliary malignant disease and other malignant disease.

DESIGN

Retrospective review of case series in our experience from 1980 through 1993.

SETTING

Tertiary care university teaching hospital.

PATIENTS

Fifty-two patients with pyogenic liver abscess related to the underlying cancer were divided into 2 groups. Group 1 (n=32) was composed of patients with cancer originating from the hepatic parenchyma, bile duct, and pancreas; group 2 (n=20) was composed of patients with cancer originating from other sites.

INTERVENTIONS

Parenteral antibiotics, percutaneous drainage, surgical drainage, or hepatectomy, in combinations, were employed.

MAIN OUTCOME MEASURES

Patient characteristics, symptoms, laboratory data, abscess characteristics, microbiological study, management, and outcome of the 2 groups were analyzed.

RESULTS

Thirteen patients (41%) in group 1 and 16 patients (80%) in group 2 had undergone prior anticancer treatment. Jaundice was encountered more often in group 1 than in group 2 (29 patients [91%] vs 6 patients [30%], respectively, P=.001), whereas nausea and vomiting were more frequently seen in group 2 than in group 1 (17 patients [52%] vs 6 patients[31%], respectively, P=.04). Leukocytosis, hypoalbuminemia, hyperbilirubinemia, and reversed albumin-globulin ratio were more pronounced in group 1 than in group 2 (P=.001, .02, .003, and .03, respectively). Abscesses communicating with the intrahepatic biliary tree were more frequently encountered in group 1 than in group 2 (11 patients [34%] vs 2 patients [10%], respectively, P=.03). Escherichia coli and Klebsiella pneumoniae predominated in group 1, while the bacteria species in group 2 were more diverse. The hospital mortality rates of group 1 and group 2 were 28% (9 of 32 patients) vs 10% (2 of 20 patients) (P=.04), respectively. Twenty-three patients (72%) of group 1 died of uncontrolled biliary sepsis or progressive cancer or both within 6 months after the diagnosis, while 17 patients (85%) of group 2 survived longer than 1 year without relapse of the abscess and continued with anticancer treatment.

CONCLUSIONS

Pyogenic liver abscess could be a presentation of hepatopancreatobiliary malignant disease at the preterminal stage, and carries a grave prognosis. Pyogenic liver abscess in patients with nonhepatopancreatobiliary malignant disease has a better chance of favorable outcome.

Accurate quantitation of water-amide proton exchange rates using the phase-modulated CLEAN chemical EXchange (CLEANEX-PM) approach with a Fast-HSQC (FHSQC) detection scheme

Measurement of exchange rates between water and NH protons by magnetization transfer methods is often complicated by artifacts, such as intramolecular NOEs, and/or TOCSY transfer from C alpha protons coincident with the water frequency, or exchange-relayed NOEs from fast exchanging hydroxyl or amine protons. By applying the Phase-Modulated CLEAN chemical EXchange (CLEANEX-PM) spin-locking sequence, 135 degrees (x) 120 degrees (-x) 110 degrees (x) 110 degrees (-x) 120 degrees (x) 135 degrees (-x) during the mixing period, these artifacts can be eliminated, revealing an unambiguous water-NH exchange spectrum. In this paper, the CLEANEX-PM mixing scheme is combined with Fast-HSQC (FHSQC) detection and used to obtain accurate chemical exchange rates from the initial slope analysis for a sample of 15N labeled staphylococcal nuclease. The results are compared to rates obtained using Water EXchange filter (WEX) II-FHSQC, and spin-echo-filtered WEX II-FHSQC measurements, and clearly identify the spurious NOE contributions in the exchange system.

Activation of muscarinic K+ channels by extracellular ATP and UTP in rat atrial myocytes

The effects of extracellular adenine and pyrimidine nucleotides on the acetylcholine-activated K+ channels (KACh) in rat cardiac myocytes were compared and examined by using the patch-clamp technique. In perforated-patch whole-cell recording experiments, extracellular adenosine triphosphate (ATP) reversibly caused an increase in K+ current. 8-Cyclopentyl-1,3-dipropylxanthine (CPX; 1 microM), a potent A1-adenosine-receptor antagonist, only partially antagonized the ATP-induced increase in K+ current, whereas glibenclamide (30 microM) had no effect. In cell-attached mode, adenosine and ATP activated single channels that had nearly identical conductance (29 pS) and open time (1.53 ms). These results suggest that adenosine and ATP can activate the same population of K+ channels. Uridine triphosphate (UTP; 100 microM) also caused an increase in steady-state K+ current. In cell-attached mode, the addition of UTP to the recording pipette solution (not in the bath solution) activated the channel current. The single-channel conductance and open time for UTP-induced channel current were 27 pS and 1.57 ms, respectively. These values were similar to those for the K+ channels activated by adenosine or ATP. The rank order of potency for the activation of KACh channels was adenosine = ATP > UTP. The addition of CPX (1 microM) to the pipette solution attenuated the ATP-induced channel activity by approximately 70% and fully prevented activation by AMPCPP, a less hydrolyzable ATP analog but did not cause any effect on UTP-induced channel activity. In pertussis toxin-treated cardiac myocytes, no any activity of UTP-induced KACh-channel current was observed. Our results demonstrate that extracellular ATP and UTP can directly activate KACh-channel current. This activation also was linked to pertussis toxin-sensitive G protein. The effect of extracellular ATP is mainly caused by the action on binding to A1-adenosine receptor, whereas the effect of extracellular UTP may be mediated possibly by P2u-purinergic (or 5'-nucleotide) receptor.

A multidisciplinary approach to major bile duct injury following laparoscopic cholecystectomy

BACKGROUND AND OBJECTIVES

Many series describing the management of major bile duct injuries after laparoscopic cholecystectomy have been reported with satisfactory short-term results. However, the information of their prognosis with sufficient time-period follow-up is sparse.

METHODS

Sixteen consecutive patients with major bile duct injury following laparoscopic cholecystectomy were retrospectively reviewed, including six common bile duct transections, four bile duct perforations, and six hilar strictures but without perforation. With respect to the level of bile duct injuries, there were the following based on Bismuth's classification: type 1 in six patients, type 2 in five patients, type 3 in three patients, type 4 in one patient, and type 5 in one patient. All patients received surgical management, interventional radiology and endoscopic treatment. The time periods of follow-up ranged from 37 to 72 months (mean, 52 months). The final results were rated as being excellent, good, fair, or poor, based on the criteria of symptoms, biochemical data, and radiology.

RESULTS

There was no procedure-related mortality. Ten of the 16 patients had either excellent or good results, two had fair results, and four had poor results. Of the latter four, the patients had been classified as Bismuth type 1, 3, 4, and 5, respectively, and all sustained a failed initial surgical repair.

CONCLUSIONS

Using a multidisciplinary approach, 12 (75%) of the 16 patients attained a promising result through a long-term follow-up, while those with the higher biliary stricture and with an unsuccessful initial surgical repair had a disappointing outcome.

Prognostic study of gastric cancer without serosal invasion: reevaluation of the definition of early gastric cancer

BACKGROUND

Early gastric cancer, a term defined by Japanese researchers in the 1960s, is equivalent to pT1 tumor stage regardless of nodal status. Recently, there were suggestions to exclude node-positive pT1 gastric cancer from this entity and to consider node-negative pT2 gastric cancer as early gastric cancer.

STUDY DESIGN

A survival analysis was conducted of 294 patients who underwent resection for gastric cancers confined within the gastric wall (pT1, n = 164; pT2, n = 130) between 1986 and 1992.

RESULTS

The cumulative 5-year survival rate was 93.5% for pT1 patients and 67.9% for pT2 patients, with an overall survival of 82.5%. There was a significant difference in the 5-year survival rate between node-positive and node-negative pT1 patients (72.8% versus 95.6%; p = 0.0095). The 5-year survival rate of node-negative pT2 patients (80.4%) was significantly worse than that of node-negative pT1 patients (p = 0.011) but was not significantly better than that of node-positive pT1 patients (p = 0.4). If excellent prognosis is a prerequisite for the definition of early gastric cancer, then node-positive pT1 cancer and node-negative pT2 cancer should not be considered early gastric cancer.

CONCLUSIONS

In the 1990s, now that new imaging techniques such as endoscopic ultrasonography has been introduced, the preoperative staging of gastric cancer can be made more accurately than in the 1960s, when the term "early gastric cancer" was defined. Because the prognosis of early gastric cancers, if subcategorized by nodal status, is not homogeneously excellent, a reevaluation of the definition of early gastric cancer may be necessary.

Role of hepatic resection in surgery for bilateral intrahepatic stones

BACKGROUND

Hepatic resection is the treatment of choice for unilateral intrahepatic stones. The availability of the flexible choledochoscope has greatly changed the management of intrahepatic stones. Little has been reported regarding hepatic resection for bilateral intrahepatic stones.

METHODS

Fifty-nine (15.1 per cent) of 392 patients with bilateral intrahepatic stones underwent hepatic resection. The indications and results were reported. Surgical outcome and long-term follow-up were analysed, and results were compared with those in patients not undergoing hepatectomy.

RESULTS

Fifty-nine patients underwent hepatic resection because of destruction of the left liver by repeated infection (n = 40), multiple cholangitic liver abscesses (n = 18) or associated intrahepatic cholangiocarcinoma (n = 1). The hospital mortality rate was 1.7 per cent. The majority of complications were wound infection (9 per cent), haematobilia (5 per cent) and biliary fistula (3 per cent). The incidence of residual stones after surgery was 60 per cent. One year after postoperative choledochoscopic stone extraction, the rate of complete stone clearance was 84 per cent. In patients who did not have hepatectomy the respective rates were 90.1 and 52.9 per cent. The recurrence rate for stones in the hepatectomy and no-hepatectomy groups was 12 and 33.0 per cent respectively.

CONCLUSIONS

Compared with patients not undergoing hepatectomy, those having hepatic resection had similar operative risks, fewer residual stones and a low incidence of recurrent stones (P < 0.05).

Massive extra-enteric gastrointestinal hemorrhage secondary to splanchnic artery aneurysms

BACKGROUND/AIMS

Gastrointestinal hemorrhages of obscure origin are often difficult to diagnose and manage. Of these, splanchnic artery aneurysms have emerged as an important disorder because of the increasing prevalence and formidable mortality rate associated with their rupture. We herein evaluated extra-enteric gastrointestinal bleeding related to these ruptured aneurysms.

METHODOLOGY

The medical records of 17 patients with splanchnic artery aneurysms known to be exclusively manifested as gastrointestinal bleeding were reviewed. The pathogenesis, clinical picture, diagnostic tests, management, complications, and outcomes were compiled and analyzed.

RESULTS

Of the seventeen patients, 12 patients had true aneurysms; 5 patients had false aneurysms. Pancreatitis, trauma, iatrogenic hepatobiliary injury, and atherosclerosis were the four major etiologies. The sensitivity rates measured by endoscopy, ultrasonography, computed tomography and visceral angiography were 20%, 50%, 67%, and 100%, respectively. An exact diagnosis was attained in 94% of the patients at the time of management. Transcatheter embolization was employed in 7 patients, complicated with hepatic and splenic infarcts, and pyogenic liver abscesses in 2 instances. Two patients had recurrent bleeding aneurysms post embolotherapy. Ten patients underwent surgical intervention which resulted in 2 cases of hepatic failure. One out of 5 patients with a true aneurysm died, while 4 out of 12 patients with false aneurysms eventually died. Overall, the mortality rate was 29%.

CONCLUSION

Even though the exact diagnosis can be made in most of the patients by modern imaging studies, the mortality rate was still formidable, especially in patients with false aneurysms, in whom the underlying causal diseases substantially influenced the major outcome.

Changes of adenosine triphosphate-dependent calcium uptake in microsomal fractions of rat liver during sepsis

BACKGROUND

Intracellular calcium concentration is an important regulator of cellular metabolism. Endoplasmic reticulum membranes play an important role in the regulation of cytoplasmic calcium in the mammalian liver. The characterization of the changes of calcium uptake in endoplasmic reticulum may contribute to the potential intracellular mechanisms for cellular dysfunction during sepsis.

METHODS

The effects of sepsis on the calcium uptake in rough endoplasmic reticulum of rat liver were studied. Sepsis was induced by means of cecal ligation and puncture (CLP). The control rats underwent sham operation. Microsomal fractions were isolated from the liver with differential centrifugation.

RESULTS

The calcium uptake by liver endoplasmic reticulum was decreased by 30% to 35% (p < 0.05) during early sepsis (9 hours after CLP) and by 38% to 43% (p < 0.05) during late sepsis (18 hours after CLP), respectively. The maximum velocity values for adenosine triphosphate (ATP) and for Ca2+ were also decreased by 25% to 37% (p < 0.05) during early sepsis and by 35% to 42% (p < 0.05) during late sepsis. The Michaelis-Menten constant for ATP and Ca2+ transport had no difference among three groups. The magnesium stimulation and vanadate inhibitory activity were also decreased by 17% to 38% (p < 0.05) during early sepsis and by 34% to 50% (p < 0.05) during late sepsis.

CONCLUSIONS

These data demonstrate that ATP-dependent calcium uptake in rough endoplasmic reticulum of rat liver was impaired during early and late sepsis. Because the low intracellular calcium concentration plays an important role in the regulation of cellular function, an impairment in the ATP-dependent calcium uptake by endoplasmic reticulum during early and late sepsis may have a pathophysiologic significance in contributing to the development of altered hepatic metabolism during sepsis.

Relative importance of quantifying area and vascular patterns in uveal melanomas

PURPOSE

To test whether the cross-sectional area of choroidal and ciliary body melanomas and quantification of microcirculatory networks and parallel vessels with cross-linking are features associated with death from metastatic melanoma, and to compare new with conventional histologic prognostic features.

METHODS

The cross-sectional area of 234 ciliary body or choroidal melanomas was measured from digitized images of histologic sections. The percentage of cross-sectional area occupied by two microcirculatory patterns-networks and parallel vessels with cross-linking-was calculated for the 152 tumors containing at least one focus of either pattern. Kaplan-Meier survival curves were generated based on cross-sectional and percentage of cross-sectional areas of these patterns. Cox proportional hazard regression methods related time to death from melanoma with sets of predictor variables. For each model, percent variation explained was computed.

RESULTS

Patient survival differs significantly when tumors are classified based on cross-sectional area: small (<16 mm2), medium (> or =16 mm2 but <61.4 mm2), and large (> or =61.4 mm2). Patients with tumors containing networks and parallel vessels with cross-linking microcirculation patterns that occupy 2% of cross-sectional area have a significantly worse prognosis than do those patients with tumors containing a smaller percentage of these patterns.

CONCLUSIONS

Quantifying cross-sectional tumor area and the percentage area occupied by networks and parallel vessels with cross-linking microcirculatory patterns in ciliary body and cho. roidal melanomas provides significant prognostic information. Compared with more conventional prognostic characteristics, the most dramatic increase in prognostic information is provided by determination of the presence or absence of microvascular patterns.

Ionic mechanisms of tetrandrine in cultured rat aortic smooth muscle cells

The ionic mechanism of tetrandrine, an alkaloid extracted from the Chinese medicinal herb Radix stephania tetrandrae, was investigated in A7r5 vascular smooth muscle cells. The nystatin-perforated whole-cell voltage-clamp technique was performed to examine the effects of tetrandrine on ionic currents. Tetrandrine (1-100 microM) reversibly caused an inhibition of L-type voltage-dependent Ca2+ current (I(Ca,L)) in a concentration-dependent manner. Tetrandrine did not cause any change in the overall shape of the current-voltage relationship of I(Ca,L). The IC50 value of tetrandrine-induced inhibition of I(Ca,L) was 5 microM. In the presence of Bay K 8644 (3 microM) or cyclopiazonic acid (30 microM), tetrandrine still produced a significant inhibition of I(Ca,L). The inhibitory effects of tetrandrine on I(Ca,L) exhibited tonic and use-dependent characteristics. Moreover. tetrandrine (3 microM) shifted the steady-state inactivation curve of I(Ca,L) to more negative membrane potentials by approximately -15 mV. These results indicate that tetrandrine directly inhibits the voltage-dependent L-type Ca2+ current in vascular smooth muscle cells, which may predominantly contribute to the vasodilatory actions of tetrandrine.