Biomedical subjects

C M Lo

Publications and source records attributed to C M Lo.

At least 55 records · Page 3Linked to original sources

PubMed2001

Serum vascular endothelial growth factor predicts venous invasion in hepatocellular carcinoma: a prospective study.

OBJECTIVE: To evaluate the correlation between serum vascular endothelial growth factor (VEGF) level and the clinicopathologic features in patients with hepatocellular carcinoma (HCC). SUMMARY BACKGROUND DATA: VEGF is an important angiogenic factor regulating tumor angiogenesis. A high serum VEGF level has been shown to be associated with tumor progression and metastasis in several human cancers, but its significance in HCC is unclear. The correlation between serum VEGF level and tumor pathologic features in patients with HCC has not been studied before. METHODS: Preoperative serum samples and tumor specimens were prospectively collected in 100 patients undergoing resection of HCC. Serum VEGF level was measured by enzyme-linked immunosorbent assay, and tumor VEGF expression was assessed by immunohistochemical study. Histopathologic examination was performed by a pathologist without prior knowledge of the serum VEGF level or tumor VEGF expression. RESULTS: Preoperative serum VEGF levels ranged from 15 to 1,789 pg/mL (median 269). When serum VEGF levels were compared between groups categorized by different clinicopathologic variables, significant correlation was found between a high serum VEGF level and absence of tumor capsule, presence of intrahepatic metastasis, presence of microscopic venous invasion, and advanced stage. There was a positive correlation between the serum VEGF level and tumor expression of VEGF as well as platelet count. When the 75th percentile serum VEGF level (500 pg/mL) was used as a cutoff level, the frequency of venous invasion in patients with a high serum VEGF level was significantly greater compared with patients with a low serum VEGF level. By multivariate analysis, a serum VEGF level of more than 500 pg/mL and tumor size more than 5 cm were independent preoperative factors predictive of microscopic venous invasion. During a median follow-up of 11.6 months, 48% of patients with a serum VEGF level of more than 500 pg/mL and 27% of those with a serum VEGF level of 500 pg/mL or less developed postoperative recurrence. CONCLUSIONS: These results show that a high preoperative serum VEGF level is a predictor of microscopic venous invasion in HCC, suggesting that the serum VEGF level may be useful as a biologic marker of tumor invasiveness and a prognostic factor in HCC.

Adult↗

PubMed2001

Liver transplantation in Asian patients with chronic hepatitis B using lamivudine prophylaxis.

OBJECTIVE: To report the results of liver transplantation in 31 Asian patients with chronic hepatitis B using lamivudine prophylaxis in an open-label study. SUMMARY BACKGROUND DATA: Chronic hepatitis B is a prevalent cause of end-stage liver disease in Asia, but the results of liver transplantation in these patients are poor. METHODS: Thirty-one Asian patients with chronic hepatitis B underwent liver transplantation using lamivudine prophylaxis (100 mg daily). Twenty-three (74%) patients had detectable serum hepatitis B envelope antigen (n = 18) or hepatitis B virus DNA (n = 11) before treatment, and seven had associated hepatocellular carcinoma. Lamivudine was continued indefinitely after transplantation, and hepatitis B immune globulin was not used. RESULTS: The actuarial patient and graft survival rates were 84% and 81%, respectively. Five patients died of causes unrelated to hepatitis B, and 26 patients were alive at a median follow-up of 16 months (range 6-47) after transplantation. One (3.8%) patient developed recurrent hepatitis B resulting from viral breakthrough at week 53 and survived after retransplantation using adefovir and hepatitis B immune globulin treatment. The remaining 25 surviving patients had no biochemical or histologic evidence of recurrent hepatitis, and serum hepatitis B virus DNA remained negative by polymerase chain reaction. In six patients, hepatitis B surface antigen (HBsAg) persisted or reappeared in serum. Among 19 patients who became negative for HBsAg from 5 to 431 days after transplantation, 13 developed anti-HBsAb that lasted a median of 6 months (range 1-21). None of the seven patients with hepatocellular carcinoma developed recurrent tumor. CONCLUSIONS: Asian patients with chronic hepatitis B may achieve a good outcome after liver transplantation using lamivudine prophylaxis.

Adolescent↗

PubMed2001

Improving survival results after resection of hepatocellular carcinoma: a prospective study of 377 patients over 10 years.

OBJECTIVE: To investigate whether the survival results after resection of hepatocellular carcinoma (HCC) have improved within the past decade by an analysis of a prospective cohort of patients over a 10-year period. SUMMARY BACKGROUND DATA: The surgical death rate after resection of HCC has greatly improved in recent years, but the long-term prognosis remains unsatisfactory. It remains unknown whether the survival results after resection of HCC have improved within the past decade. METHODS: The clinicopathologic and follow-up data of 377 patients who underwent curative resection of HCC between January 1989 and January 1999 were prospectively collected. These patients were categorized according to two time periods: before 1994 (group 1, n = 136) and after 1994 (group 2, n = 241). The two groups were compared for clinicopathologic data and survival results. The prognostic factors for disease-free survival were further analyzed to identify the factors that might have led to improved survival outcomes. RESULTS: The overall and disease-free survival results were significantly better in group 2 compared with group 1. Patients in group 2 had significantly higher proportions of subclinical presentation, small tumors, and tumors of early pTNM stage. There were also significantly lower frequencies of histologic margin involvement, less intraoperative blood loss, and a lower transfusion rate in group 2. By multivariate analysis, early pTNM stage, subclinical HCC, and no perioperative transfusion were independent favorable prognostic factors for disease-free survival. CONCLUSIONS: Significant improvement of overall and disease-free survival results after resection of HCC has been achieved within the past decade as a result of advances in the diagnosis and surgical management of HCC. Earlier diagnosis of HCC by better imaging modalities, increased detection of subclinical HCC by screening of high-risk patients, and a reduced perioperative transfusion rate were identified as the major contributory factors for the improved outcomes.

Adult↗

PubMed2001

Gill parasites of Cephalopholis argus (Teleostei: Serranidae) from Moorea (French Polynesia): site selection and coexistence.

The distribution and coexistence of gill ectoparasites of 121 specimens of Cephalopholis argus Bloch et Schneider, caught between October 1994 and October 1995, were investigated. Adults of the monogenean Benedenia sp. and copepod Hatschekia sp., the larval caligid copepod Caligus sp. (copepodite and chalimus stages), and praniza larvae of the isopod Gnathia sp. were found. All species were aggregated within the host population. Infracommunities were poor, with only 40.5% of fish infected by two parasite species. Only two individual fish harboured all the parasite species observed at the component community level. Prevalences were less than 50% and mean intensities were low (less than 6 parasites/host). No dominant parasite species were observed in the host population. The spatial distribution of each parasite species was studied on different partitions of the gill arches. Adult parasite stages that are mobile showed much overlap in their distribution, whereas temporarily attached larvae of Caligidae were more site specific. Copepodite and chalimus larvae showed niche restriction that is probably due to gregarious behaviour. Positive associations between caligid larvae reflected intraspecific interaction for site and/or resources. Each of the Caligus sp. larval stages prefers specific sites, as do the adults, which occur exclusively in the buccal cavity of the host. Infracommunities were too poor and too few to induce processes of interspecific competition.

Animals↗

PubMed2001

Correlated motion and oscillation of neighboring cells in vitro.

It has long been realized that fibroblastic and epithelial cells establish recognizable patterns in tissue culture. This behavior implies that neighboring cells interact with one another to produce organized populations. Interaction between cells that are separated by many intervening cells is also possible and is demonstrated here using a special configuration of a biosensor referred to as electric cell-substrate impedance sensing (ECIS). Normally the electrical impedance of a single electrode covered with a confluent cell layer is measured, and the morphological changes of the cells are reflected in the impedance. In this case the cells are cultured on two closely spaced electrodes whose impedances are measured independently as a function of time, and communication between the cell populations is revealed as a correlation between these two time series. We also report for the first time another striking manifestation of dynamic cell interaction, where confluent layers of Madin-Darby canine kidney cells (MDCK) on a single electrode are observed to oscillate in synchrony with a period of approximately 2.5 h.

Animals↗

PubMed2001

[Dental caries in the public primary schools dependent on the Nabil Choucair Health Center in Dakar, Senegal].

It is a holy study of observation and prevalence concerning a population of 268 pupils in first degree of the primary schools depending on the health center Nabil Choucair. 82% of these pupils have dental decay with DMFT egals 3.94. Our results suggest needs of preventive intervention on the intention to reach the objectives health for all by 2000 relatively to dental health in Senegal.

Catchment Area, Health↗

PubMed2000

Different risk factors and prognosis for early and late intrahepatic recurrence after resection of hepatocellular carcinoma.

BACKGROUND: Recent studies have shown that the prognosis of recurrent hepatocellular carcinoma (HCC) after resection was dependent on the time of recurrence. The current study investigated whether early and late intrahepatic recurrences were associated with different risk factors and prognostic factors. METHODS: After curative resection of HCC, 246 patients were followed prospectively for recurrence. Intrahepatic recurrences were classified into early (</= 1 year) and late (> 1 year) recurrences. Risk factors for recurrence and prognostic factors for survival after recurrence in each group were analyzed. RESULTS: Early and late intrahepatic recurrences developed in 80 patients and 46 patients, respectively. By multivariate analysis, preoperative tumor rupture (P = 0.022) and venous invasion (P < 0.001) were independent risk factors for early recurrence, whereas cirrhosis (P = 0.018) was the only significant risk factor for late recurrence. By comparing histologic features of resected recurrent and primary tumors, 8 of 9 resected early recurrent tumors (89%) were classified as intrahepatic metastases, whereas all 6 resected late recurrent tumors (100%) were multicentric occurrences. Despite similar treatments, the prognosis for patients with early recurrence was worse than that of patients with late recurrence (median survival of 15.8 months vs. 29.6 months; P = 0.005). Independent prognostic factors for early recurrence were serum albumin level and initial tumor pTNM classification, whereas only serum bilirubin level was found to be an independent prognostic factor for late recurrence. CONCLUSIONS: Early and late intrahepatic recurrences after resection of HCC were associated with different risk factors and prognostic factors. Early recurrences appear to arise mainly from intrahepatic metastases, whereas late recurrences are more likely to be multicentric in origin. The current study suggests that different strategies may be needed for the prevention and management of early and late recurrences. Further studies based on genetic analysis of clonal origins of tumors are required to clarify fully the mechanism of early and late recurrences after resection of HCC.

Adult↗

PubMed2000

Safety of donors in live donor liver transplantation using right lobe grafts.

HYPOTHESIS: Right lobe donation was advocated for adult-to-adult live donor liver transplantation but the safety of the donor is still a major concern. We hypothesize that right lobe donation is safe if the lowest limit of volume of liver remnant that can support donor survival is known. DESIGN: Retrospective analysis of data collected prospectively. SETTING: Tertiary hepatobiliary surgery referral center. PATIENTS: Twenty-two live donors involved in adult-to-adult right lobe liver transplantation from May 1996 to June 1999. INTERVENTIONS: The right lobe grafts were obtained by transecting the liver on the left side of the middle hepatic vein. Liver transection was performed by using an ultrasonic dissector, without using the Pringle maneuver. The left lobe volume was measured by computed tomographic volumetry and the ratio of left lobe volume to the total liver volume was calculated. MAIN OUTCOME MEASURES: Hospital mortality rate and complication rate. RESULTS: The median blood loss was 719 mL (range, 200-1,600 mL). Only one donor, who had thalassemia, received 1 U of homologous blood transfusion. Postoperative complications included wound infection, incision hernia, and cholestasis in 1 donor whose liver showed 20% fatty change and who had a left lobe-total liver volume of 0.34. Another donor with 15% fatty change in the liver and a left lobe-total liver volume ratio of 0.27 developed prolonged cholestasis. Two other donors with left lobe-total liver volume ratios of 0.27 but with mild steatosis (<5%) did not develop postoperative cholestasis. Postoperative complications also included 1 case of biliary stricture and 1 case of small bowel obstruction. Both complications were adequately treated. There was no donor mortality. All donors are well and have returned to their previous occupations. CONCLUSION: Live donation of right lobe graft for adult-to-adult liver transplantation is safe provided that the residual liver volume exceeds 30% of the total liver volume and the liver itself is normal or only mildly affected by steatosis.

Adolescent↗

PubMed2000

Transarterial chemoembolization for inoperable hepatocellular carcinoma and postresection intrahepatic recurrence.

BACKGROUND AND OBJECTIVES: The role of transarterial chemoembolization (TACE) for inoperable hepatocellular carcinoma (HCC) has remained controversial, and its efficacy for postresection intrahepatic recurrence has not been fully assessed. A study was performed to evaluate the treatment results and prognostic factors of TACE treatment in these patients. METHODS: Clinicopathologic data and treatment results of 384 patients with inoperable HCC and 100 patients with postresection recurrent HCC treated with TACE were collected prospectively and analyzed. RESULTS: TACE was associated with an overall treatment morbidity rate of 23% (112/484) and mortality rate of 4.3% (21/484). A particularly high mortality rate of 20% (9/45) was observed among patients with tumors > 10 cm and pretreatment serum albumin level </= 35 g/L. The overall 1-year, 3-year, and 5-year survival rates from the time of first TACE treatment were 49%, 23%, and 17% respectively. Tumor size </= 10 cm and serum albumin level > 35 g/L were independent favorable prognostic factors. TACE in patients with postresection recurrent HCC was associated with less morbidity, mortality, and a better survival outcome compared with patients with primary inoperable HCC, but this was largely related to smaller tumor size and better liver function in the former group at the time of TACE treatment. CONCLUSIONS: TACE in patients with inoperable HCC was associated with significant morbidity and mortality, and the survival benefit was limited. Better patient selection in terms of tumor size and liver function may improve treatment results. Patients who have a tumor > 10 cm and poor liver function (serum albumin </= 35 g/L) may not be suitable candidates for TACE treatment.

Adult↗

PubMed2000

Role of laparoscopic ultrasonography in intraoperative localization of pancreatic insulinoma.

BACKGROUND: A combination of digital palpation and ultrasonography plays an important role in locating insulinomas intraoperatively. Laparoscopic resection of insulinomas has been described recently, but experience in locating insulinomas during laparoscopy is lacking. METHODS: From January 1998 to January 1999, three patients with pancreatic insulinomas underwent laparoscopy and laparoscopic ultrasonography aimed at intraoperative localization and potential resection. The role of laparoscopy and laparoscopic ultrasonography in locating insulinomas is evaluated. RESULTS: Preoperative localization studies were routinely performed, and two patients had an occult tumor before laparoscopy. None of the tumors was detected by laparoscopic examination, but laparoscopic ultrasonography identified solitary tumors located at the body and tail of the pancreas. Conversion to laparotomy was performed in one patient as a planned procedure. One patient underwent laparoscopic enucleation, whereas the other had a laparoscopic distal pancreatectomy. CONCLUSIONS: Laparoscopic ultrasonography seems to be sensitive in locating insulinomas at the body and tail of the pancreas. It optimizes and facilitates resection of insulinomas through a minimally invasive approach.

Adult↗

PubMed2000

Determining resectability for hepatocellular carcinoma: the role of laparoscopy and laparoscopic ultrasonography.

We reviewed our experience with preoperative determination of resectability in patients with hepatocel-lular carcinoma (HCC) over the last 10 years, and evaluated the role of laparoscopy with laparoscopic ultrasonography (USG) since we instituted this technique in June 1994. From January 1989 to December 1998, 500 of 1741 patients with HCC (28.7%) were considered suitable for hepatic resection after preoperative assessment. Significantly more contrast-enhanced computed tomography (CT) scans and fewer percutaneous USGs or hepatic arteriograms were performed in the 299 patients managed since June 1994 (group 2) than in the 201 patients managed before then (group 1). One hundred and ninety-eight patients in group 2 (66%) underwent laparoscopy with laparoscopic USG. Unresectable disease was found in 41 patients in group 1 (20.4%) (all at laparotomy), and in 68 patients in group 2 (22.7%) (16 at laparotomy without laparoscopic examination, 31 at laparoscopic examination alone, and 21 at laparotomy after an inconclusive laparoscopic examination) (P = 0.5). The most common features of unresectable disease were the presence of bilobar intrahepatic metastases and an inadequate liver remnant with cirrhosis. The adoption of the laparoscopic examination after June 1994 improved the overall resection rate at laparotomy in group 2 from 77.3% to 86. 2%, which was better than that in group 1 (79.6%, P = 0.057). For patients with unresectable disease, the operation time and hospital stay were significantly shorter in group 2. The postoperative morbidity and mortality rates were 9.8% and 4.9%, respectively, in group 1, and 5.9% and 2.9% in group 2. There was no operative morbidity in the 31 patients who had unresectable disease detected by the laparoscopic examination alone. Laparoscopy with laparoscopic USG avoids unnecessary laparotomy, and has a definite role in determining resectability in patients with HCC.

Adolescent↗

PubMed2000

Cell movement is guided by the rigidity of the substrate.

Directional cell locomotion is critical in many physiological processes, including morphogenesis, the immune response, and wound healing. It is well known that in these processes cell movements can be guided by gradients of various chemical signals. In this study, we demonstrate that cell movement can also be guided by purely physical interactions at the cell-substrate interface. We cultured National Institutes of Health 3T3 fibroblasts on flexible polyacrylamide sheets coated with type I collagen. A transition in rigidity was introduced in the central region of the sheet by a discontinuity in the concentration of the bis-acrylamide cross-linker. Cells approaching the transition region from the soft side could easily migrate across the boundary, with a concurrent increase in spreading area and traction forces. In contrast, cells migrating from the stiff side turned around or retracted as they reached the boundary. We call this apparent preference for a stiff substrate "durotaxis." In addition to substrate rigidity, we discovered that cell movement could also be guided by manipulating the flexible substrate to produce mechanical strains in the front or rear of a polarized cell. We conclude that changes in tissue rigidity and strain could play an important controlling role in a number of normal and pathological processes involving cell locomotion.

3T3 Cells↗

PubMed2000

EUS for detection of occult cholelithiasis in patients with idiopathic pancreatitis.

BACKGROUND: The aim of this study was to evaluate the use of endoscopic ultrasonography (EUS) in detecting occult cholelithiasis and determining a probable etiology in patients classified as having idiopathic pancreatitis by conventional radiologic methods. METHODS: A prospective study was performed in 89 consecutive patients with acute pancreatitis. Transcutaneous ultrasonography (US), CT, or both was performed on all patients within 24 hours of admission. Endoscopic retrograde cholangiopancreatography (ERCP) was performed in all patients with confirmed or suspected biliary pancreatitis. EUS was performed in patients classified as having idiopathic pancreatitis. RESULTS: Cholelithiasis was identified in 64 patients (72%) by conventional radiologic methods. Eighteen patients (20%) were classified as having idiopathic pancreatitis after evaluation by US (all 18 patients), repeated US (9 patients), CT (6 patients) and ERCP (13 patients). EUS performed in these 18 patients revealed small gallbladder stones (1 to 9 mm) in 14 patients; 3 were found to have concomitant choledocholithiasis. All stones were confirmed by subsequent ERCP and cholecystectomy. The remaining 4 patients in whom no etiology was identified had no clinical or radiologic evidence of cholelithiasis at a median follow-up of 22 months. CONCLUSION: Cholelithiasis is detected by EUS in a large number of patients classified as having idiopathic pancreatitis by conventional radiologic examinations. With identification of a biliary cause of acute pancreatitis, treatment can be initiated early, thereby reducing the risk of recurrent pancreatitis with its associated morbidity and mortality. EUS is a valuable diagnostic modality in the management of patients with acute pancreatitis.

Acute Disease↗

PubMed2000

Parasites of recruiting coral reef fish larvae in New Caledonia.

Recruiting coral reef fish larvae from 38 species and 19 families from New Caledonia were examined for parasites. We found 13 parasite species (Platyhelminthes: Monogenea, Cestoda and Trematoda) but no acanthocephalan, crustacean or nematode parasites. Over 23% of individual fish were infected. Didymozoid metacercariae were the most abundant parasites. We conclude that most of the parasites are pelagic species that become 'lost' once the fish larvae have recruited to the reef. Larval coral reef fish probably contribute little to the dispersal of the parasites of the adult fish so that parasite dispersal is more difficult than that of the fish themselves.

Animals↗

PubMed2000