Protein characterization of fluorosed human enamel

Despite extensive investigation, the development mechanism or mechanisms resulting in dental fluorosis are unknown. Several hypotheses suggest abnormal matrix synthesis, secretion, and delayed and/or defective matrix degradation with retention of enamel protein. The purpose of this study was to characterize the protein composition of fluorosed human enamel. Nine permanent moderately fluorosed (developed in a 3.2 ppm H2O area) and ten permanent normal control teeth (from individuals with < 0.2 ppm F in their drinking water) were evaluated. The enamel fluoride concentration, protein content, and amino acid composition were determined for each tooth. The enamel proteins were further characterized by gel electrophoresis and by Western blot analysis by means of polyclonal antibodies raised against recombinant amelogenin protein. Fluorotic enamel had significantly elevated (p = 0.0001) F levels compared with normal enamel (mean [F-] fluorosed = 431 ppm; mean [F-] control = 62 ppm). While there was a significantly greater protein content by weight in fluorosed enamel compared with normal enamel (mean fluorosed = 0.27%; mean control = 0.11%), the amino acid profiles were similar for fluorosed and normal enamel. Gel electrophoresis showed fluorosed enamel to have a greater diversity of primarily low-molecular-weight proteins compared with normal enamel. Western blot analysis did not indicate retention of amelogenin in either fluorosed or normal enamel. This investigation showed that the protein content of fluorosed enamel was greater than that of normal enamel; however, the amino acid compositions were similar for fluorosed and normal enamel. Furthermore, there does not appear to be retention of significant amounts of amelogenin in fully mature, moderately fluorosed human enamel. Although delayed removal of the enamel matrix proteins may play a role in the hypomineralization defects seen in fluorosed enamel, the majority of these proteins are absent in the mature tissue of these moderately fluorosed teeth.

The genotypes of hepatitis C virus in patients with chronic hepatitis C virus infection in southern Taiwan

To investigate the genotype distribution of hepatitis C virus (HCV) in southern Taiwan, the sera from 56 patients with chronic HCV infection were studied. Twenty-nine patients were men and 27 were women. Age ranged from 22 to 65 years (mean, 47.3 +/- 11.4). Eighteen of them had chronic persistent hepatitis, 27 had chronic active hepatitis, and 11 had liver cirrhosis. HCV RNA was detected by reverse transcription-nested polymerase chain reaction using primers derived from the 5'-noncoding region. The genotypes of HCV were determined by amplification of the core region with the type-specific primers as described by Okamoto et al.. All sera were positive for HCV RNA. The prevalence rates of genotypes were as follows: 1b/II, 44.6%(25/56); 2a/III, 41.1%(23/56); 2b/IV, 3.6%(2/56); mixed 1b/I + 2a/III, 5.4%(3/56): mixed 1b/II + 2b/IV, 1.8%(1/56) and type unclassified 3.6%(2/56). The distribution of genotypes was not related to the patients' age, sex, and histological changes. Nevertheless, patients having past history of blood transfusion had a significantly higher rate of HCV type 2a/III infection (72.2% versus 34.2%, p < .05, chi-square test). We concluded that both of the HCV genotypes 1 b/II and 2a/III are predominant types in southern Taiwan and regional HCV genotype distribution may differ even within this island. Selective transmission of specific genotypes may pass along different infectious routes.

Techniques for intrasplenic hepatocyte transplantation in the large animal model

BACKGROUND

The preferred therapy for acute and chronic liver insufficiency and severe heritable disorders of liver metabolism is whole-organ transplantation. However, due to the shortage of organ donors and high cost, alternative therapeutic approaches have been proposed, including transplantation of normal allogeneic hepatocytes. Recently, it has been reported that many hepatocytes transplanted into the spleen migrated to the liver. We therefore carried out a series of large-animal experiments to reexamine the intrasplenic route and to develop a method for large-scale hepatocellular transplantation in pigs.

METHODS

Allogeneic porcine hepatocytes were transplanted using the following routes: (1) retrograde injection of cells via the splenic vein, (2) intraarterial injection of cells, (3) direct intrasplenic injection of cells after laparotomy, (4) percutaneous intrasplenic injection of cells under laparoscopic control, (5) laparoscopic intrasplenic injection of cells. The number of cells injected varied from 2 x 10(9) to 10 x 10(9) cells.

RESULTS

Of all the methods tested, only direct intrasplenic injection of 2 bln of cells was found to be compatible with survival. However, even with this "small" number of cells (2% original liver mass), there was a significant risk of spleen infarction, perisplenic adhesion formation, and portal vein thrombosis. The laparoscopic approach was found to be reliable, simple, and safe.

CONCLUSION

Even though the spleen is considered by many authors the optimal site for hepatocellular transplantation, transplantation of cells in a number needed to support the failing liver may be associated with significant complications, morbidity, and mortality.

Platelet-derived growth factor is an autocrine stimulator for the growth and survival of human esophageal carcinoma cell lines

Platelet-derived growth factors (PDGF) are important mitogens for mesenchyme-derived cells. Neither PDGF nor PDGF receptors (PDGFR) are expressed in epithelial cells under normal physiological conditions. However, we have found that PDGF-BB induces c-jun expression and promotes the growth of the human esophageal carcinoma cell line CE48T/VGH. Scatchard analysis revealed the presence of 6 x 10(5) binding sites for PDGF-BB per cell, with a Kd of 9.7 nM. Furthermore, our data indicate that CE48T/VGH expresses beta type PDGFR (PDGFRbeta) with in vitro auto-kinase activity. We have also found that CE48T/VGH expresses the mRNA of the PDGF-A and PDGF-B chains and secretes PDGF molecules. Addition of anti-PDGF neutralizing antibody significantly decreased cell numbers of CE48T/VGH under serum-free conditions. The detached cells underwent apoptosis characterized by micronucleation. These results suggest that expression of the PDGF autocrine system may not only provide the growth advantage but also prevent the apoptosis for CE48T/VGH.

The practice of Chinese medicine in Taiwan

This paper examines the practice of Chinese medicine in Taiwan. Using a national sample survey of Chinese medicine physicians, supplemented by another national survey of Chinese medicine hospitals and government records, the authors study the education and training background of Chinese medicine physicians, their mode of practice, their productivity measured by patient visits, and the practice characteristics of Chinese medicine hospitals. Moreover, the authors investigate the relationship between the resource input, the public health insurance contract, and the number of patient visits Chinese medicine physicians provided. Results of this study are used to make several recommendations on the appropriate way of integrating the practice of Chinese medicine into the modern health care system. Many of these recommendations may also be applicable to other countries that are contemplating integrating traditional or alternative medicine into their health care systems.

Characterization of Cryptococcus neoformans by random DNA amplification

Random amplified polymorphic DNA (RAPD) was optimized and used to distinguish between the varieties and serotypes of Cryptococcus neoformans. The RAPD technique distinguished between serotypes A, D or AD within C. neoformans var. neoformans, and revealed further differentiation within each serotype. Four RAPD profiles were clearly recognizable within C. neoformans var. gattii, although its two serotypes, B and C, were only differentiated with one primer combination out of seven.

Surgical treatment of choledochal cyst in adults: results and long-term follow-up

BACKGROUND/AIMS

Results of the surgical management of 60 adults with choledochal cysts at Chang Gung Memorial Hospital Taipei are presented.

PATIENTS AND METHODS

All patients were diagnosed and surgically managed during the period between March 1979 and December 1992. There were 47 females and 13 males, with ages ranging from 16 to 81 years (mean age = 31.9 years). Of the total, there were 41 Type I, one Type II, 14 Type IV, and four Type V choledochal cysts classified according to Todani's classification system. The definite surgical procedures were cyst excision and hepatico-jejunostomy in 43 cases in type I and IV diseases, one cyst excision in type II disease, two hepatectomy for type V disease, cyst enterostomy in seven cases, and T-tube choledochocystostomy in seven cases.

RESULTS

The operative mortality rate was 3.3% and the complication rate related to the surgical procedure was 20%. Early postoperative complications include wound infection, leakage of anastomosis, acute pancreatitis, septic shock, left pleural effusion, and intra-abdominal abscessing. Reoperations were needed in the early postoperative days in two cases due to hepatico-jejunostomy leakage and intraabdominal abscess formation. Long-term surgical outcome, concerning recurrence of symptoms, was related to the following factors, excluding the factors of surgery: presence of bile duct lithiasis, common channel less than 22 mm, presence of preoperative pancreatitis and acute angle type pancreaticobiliary unions. Only common channel less than 22 mm is statistically significant. The percentage of recurrence of the symptoms after resectional surgery was 32.5% in the long term follow-up period. Most of the cases responded well to an antibiotics treatment. Three of the cases required a second operation or PTCD as well as dilatation to treat the recurrent cholangitis.

CONCLUSION

Although the recurrence of symptoms is not uncommon and satisfactory explanation of the analysed factors is still the treatment of choice for adult patients with choledochal cysts.

Urethral recurrence in patients with orthotopic ileal neobladders

PURPOSE

We identified the risk of urethral recurrence following cystectomy for transitions cell bladder carcinoma, stratified by pathological characteristics of the bladder tumor and type of urinary diversion.

MATERIALS AND METHODS

The pathological characteristics and clinical courses of 174 men with a Kock ileal neobladder and 262 with a cutaneous urinary diversion were analyzed for time to urethral recurrence.

RESULTS

Urethral recurrence was identified in 34 patients at a median of 1.6 years after cystectomy, for an overall 7.9% 5-year risk of recurrence. Carcinoma in situ (p = 0.71) and multifocality (p = 0.17) did not independently confer an increased risk of recurrence. Prostatic urethral involvement, particularly stromal invasion, significantly increased the probability of recurrence (p < 0.001). Patients with a Kock ileal neobladder had a significantly lower probability of recurrence compared to those with cutaneous diversion (p = 0.015), even when associated with prostatic urethral involvement.

CONCLUSIONS

Patients with a Kock ileal neobladder have a lower risk of urethral recurrence than those with cutaneous urinary diversion, even when associated with a high risk pathological condition predicting increased risk of urethral recurrence.

Effect of chronic captopril treatment on circulating and tissue renin-angiotensin system in SHR rats

AIM

To study the effect of captopril treatment and its withdrawal on the circulating and tissue peptidyl-dipeptidase A, angiotensinogen (AGT), and angiotensin II (A II), in relation to left ventricular hypertrophy (LVH) and systolic blood pressure (SBP).

METHODS

SHR male rats were given captopril 100 mg.kg-1.d-1 [SHRcap, number (n) = 43] orally in mixture with milk powder as vehicle from intrautero period of 16 wk of age. Rats were killed at 16 (n = 19) and 40 (n = 24) wk of age, respectively. Male, age-matched untreated SHR and WKY rats served as controls. SBP, left ventricular mass/body weight (LVM/BW) ratio, left ventricular (LV) myocardium and plasma A II concentration, aortic and serum peptidyl-dipeptidase A activity, AGT mRNA level in kidney and liver, renal renin mRNA level were determined.

RESULTS

Captopril treatment decreased SBP and reduced LVM/BW at 16 and 40 wk of age, and persistently inhibited LV myocardium A II, aortic peptidyl-dipeptidase A activity, and AGT gene expression in kidney even after the treatment was removed. Nevertheless, no changes were found in plasma A II concentration, serum peptidyl-dipeptidase A activity, and AGT mRNA level in liver by captopril therapy. Renal renin mRNA level was low in SHR and WKY rats, but it was increased by captopril treatment. Tissue renin-angiotensin system (RAS) such as AGT mRNA in kidney, aortic peptidyl-dipeptidase A activity, and LV myocardium A II, rather than circulating RAS (AGT mRNA in liver, renin mRNA in kidney, serum peptidyl-dipeptidase A activity and plasma A II), were persistently inhibited by early captopril treatment, even after the withdrawal of the treatment.

CONCLUSION

The long-term inhibition of tissue RAS is one of the mechanisms of the persistent hypotensive effect of captopril treatment.

Clinical experience with a porcine hepatocyte-based liver support system

The only clinically proven effective treatment of fulminant hepatic failure (FHF) is orthotopic liver transplant (OLT). However, many patients die before an organ becomes available. Thus, there is a need for development of an extracorporeal liver support system to "bridge" these patients either to OLT or spontaneous recovery. We developed a bioartificial liver (BAL) based on plasma perfusion through a circuit of a hollow-fiber cartridge seeded with matrix-anchored porcine hepatocytes to treat patients with severe acute liver failure. Two groups of patients were studied. Group 1 (n = 12): patients with FHF. All patients were successfully "bridged" to OLT. "Bridge" time to OLT was 21-96 hr (mean: 39.3 hr). All patients were discharged neurologically intact. Reversal of decerebration was noted in all 11 deep stage 4 coma patients. There was reduction in intracranial pressure (ICP mmHg, 18.2 +/- 2.2 to 8.5 +/- 1.2; p < 0.004) and increase in cerebral perfusion pressure (CPP mmHg, 71.1 +/- 4.0 to 84.7 +/- 2.6; p < 0.006). Laboratory values pre- and post-BAL treatment: glucose (mg/dl) 122 +/- 11 to 183 +/- 21, p < 0.002; ammonia (mumol/l) 155.6 +/- 13.2 to 121.6 +/- 9.5, p < 0.02; total bilirubin (mg/dl) 21.6 +/- 2.8 to 18.2 +/- 2.2, p < 0.001; PT (sec) 23.2 +/- 1.7 to 21.9 +/- 1.0, p < 0.3. Group II (n = 8): patients with chronic liver failure experiencing acute exacerbation. Two patients survived and later underwent OLT. Six patients (not OLT candidates) died 1-14 days after last BAL treatment. Laboratory values pre- and post-treatment: ammonia (mumol/l) 201 +/- 47 to 143 +/- 25, p < 0.06; total bilirubin (mg/dl) 22.8 +/- 5.2 to 19.5 +/- 4.4, p < 0.01; PT (sec) 22.5 +/- 2.0 to 21.8 +/- 1.1, p < 0.6.

CONCLUSION

our clinical experience with the BAL suggests that it may serve as "bridge" to OLT in patients with FHF primarily by reversing intracranial hypertension, but it is not a substitute for OLT in patients with end-stage liver disease who are non-transplant candidates.

Introduction and expression of foreign DNA in isolated spinach chloroplasts by electroporation

An electroporation-mediated method for the study of foreign gene expression within chloroplasts has been developed. The chloroplast expression vector pHD203-GUS, which consists of coding regions for beta-glucuronidase (GUS) and chloramphenicol acetyltransferase (CAT) separated by a double psbA promoter fragment from pea (in opposite orientation) was electroporated into spinach chloroplasts and the transient gene expression was examined. Conditions for the expression of the reporter genes have been optimized. Both CAT and GUS activities were detected in chloroplasts electroporated with pHD203-GUS, but not with nuclear expression vector pBI221 or negative control pUC18. No GUS activity was detected when pHD203-GUS was electroporated into spinach protoplasts. Dot immunoblot analysis using anti-GUS antibody confirmed the existence of GUS protein in chloroplasts electroporated with chloroplast-specific vector but not the negative controls, excluding the possibilities of endogenous GUS or bacterial contamination. The expression of GUS protein in treated chloroplasts was further confirmed by Western blot analysis.

Treatment of chronic hepatitis C with interferon-alpha: a preliminary report

Interferon alpha (IFN-alpha) has been indicated to be dramatically effective in some but not all patients with chronic hepatitis C virus (HCV) infection. We investigated prospectively 27 patients of chronic hepatitis C, 12 females and 15 males, treated with IFN-alpha for a better regimen of the therapy and for any effective predictor of response to the treatment. All patients were treated with 3 to 6 million units (MU) of recombinant IFN-alpha 2b (n = 15) or lymphoblastoid IFN-alpha (n = 12) given 3 times weekly for 12 to 36 weeks. Patients with normal alanine aminotransferase (ALT) value during therapy, who sustained this response throughout 6 months follow-up after treatment was completed, were grouped into the complete responders. Patients with normal ALT value during therapy but who relapsed after treatment completed, were grouped as partial responders. Non-responders were defined as patients without normal ALT value during therapy. The rates of complete response, partial response, and non-response were 29.6%, 40.8%, and 29.6%, respectively. The degree of response to IFN-alpha therapy was not related to age, sex, type of IFN-alpha, history of blood transfusion, the state of liver pathology, or pretreatment level of ALT value. The complete responsive rate to IFN-alpha was higher in patients treated with total dose above 215 MU [38.1% (8/21) vs. 0% (0/6), p = 0.06], in patients treated for at least 24 weeks [40% (8/20) vs. 0% (0/7), p < 0.05], and in patients with non-genotype 1b/II HCV infection [40% (8/20) vs. 0% (0/7), p < 0.05]. We concluded that IFN-alpha was effective in the treatment of chronic HCV infection, particularly in those other than HCV genotype 1b/II. A high-dose, and long-duration regimen may be recommended for better response of chronic hepatitis C to IFN-alpha therapy.

Treatment of hypercholesterolemia in the Watanabe rabbit using allogeneic hepatocellular transplantation under a regeneration stimulus

Numerous studies have reported successful allotransplantation of hepatocytes. However, none have shown long-term correction of a liver-related metabolic defect. In this study, we used a method of regional hepatocyte transplantation and subsequent induction of transplanted cell proliferation by regeneration response in the transplant-bearing liver lobes. New Zealand White rabbits were used as cell donors and Watanabe heritable hyperlipidemic (WHHL) rabbits were used as cell recipients (2 x 10(8) cells/rabbit). All recipient rabbits were maintained on daily cyclosporine. Two weeks after baseline serum cholesterol determination, group I WHHL rabbits (n = 7) received an infusion of cells into the right lateral liver lobe, and a loose ligature was placed around the portal venous branch supplying the anterior lobe. After 1 week, to allow engraftment, the portal venous branch was ligated, which resulted in the atrophy of the affected liver parenchyma and induction of hyperplasia in the transplant-bearing liver tissue. Group II rabbits (n = 6) were transplanted with New Zealand White hepatocytes without portal branch ligation (PBL) and group III rabbits (n = 4) were subjected to sham transplantation (saline) and PBL. The experimental period extended to 150 days after transplantation. All WHHL rabbits transplanted with normal hepatocytes showed reduction in serum cholesterol and low-density lipoprotein (LDL) levels. Group I (PBL-stimulated) recipients demonstrated a more pronounced and sustained effect than group II animals (P < 0.05). Group III controls showed only a slight, typical for aging decrease in serum cholesterol. Group I recipient livers perfused with LDL labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethyl indocarbocyanine perchlorate (DiI) showed much higher numbers of DiI-LDL-positive hepatocytes than those of group II recipients. In conclusion, a liver regeneration stimulus enhanced the population of transplanted hepatocytes and their functional effect in a large animal model of inborn error of liver metabolism.

Transitional cell carcinoma involving the prostate with a proposed staging classification for stromal invasion

PURPOSE

We investigated the effect on survival of transitional cell carcinoma of the prostatic urethra, ducts and stroma, and determined the difference between prostatic stromal involvement occurring via direct extension through the bladder wall versus stromal invasion arising intraurethrally.

MATERIALS AND METHODS

Between August 1971 and December 1989, 489 men underwent radical cystoprostatectomy for transitional cell carcinoma, including 143 (29.2%) identified with prostate involvement by transitional cell carcinoma, in the cystectomy specimen. Patients were separated into 2 groups: 1-19 in whom the primary bladder tumor extended full thickness through the bladder wall to invade the prostate (classified as P4a) and 2-124 in whom prostate involvement arose from within the prostatic urethra.

RESULTS

Five-year recurrence-free and overall survival rates were 25 and 21%, respectively, in group 1 versus 64 and 55%, respectively, in group 2. In the 124 patients in group 2 survival rates were similar for those with prostatic urethral tumors or carcinoma in situ and ductal tumors (no stromal invasion). Five-year overall survival rates without and with stromal invasion were 71 and 36%, respectively (p < 0.0001). Transitional cell carcinoma of the prostatic urethra or ducts does not alter survival predicted by primary bladder stage alone. Prostatic stromal invasion arising intraurethrally significantly decreases survival, which varies based on primary bladder stage (64.6% in stage P1, 30.8% in stages P2/P3a and 13.6% in stage P3b, p = 0.0001). P1 bladder tumors with prostatic stromal invasion arising intraurethrally had a significantly higher survival rate than P4a tumors (64.6 versus 21%, p = 0.0001). P3b bladder tumors with stromal invasion had a survival rate similar to that of P4a tumors (p = 0.78).

CONCLUSIONS

Prostatic urethral or ductal transitional cell carcinoma does not alter survival determined by primary bladder stage alone and it should not be classified as P4a. Prostatic stromal involvement arising intraurethrally significantly decreases survival predicted by primary bladder stage alone. P1 bladder tumors with prostatic stromal invasion arising intraurethrally have a significantly higher survival rate than P4a tumors and they should be separately classified as P1str. Muscle invasive (P2/P3a) bladder tumors with stromal invasion have a higher survival rate than P4a tumors (no statistical significance) and they should be designated separately (that is P2str). P3b bladder tumors with prostatic stromal invasion arising intraurethrally are indistinguishable from P4a tumors.

Protection against rotavirus infections by DNA vaccination

DNA vaccines encoding for murine rotavirus proteins VP4, VP6, or VP7 were tested in adult BALB/c mice for their ability to induce immune responses and protect against rotavirus challenge. A gene gun was used to inoculate vaccines into the epidermis. Rotavirus-specific serum antibodies, as measured by ELISA, and virus-specific cytotoxic T lymphocyte responses were generated by each of the three vaccines, but virus-neutralizing antibodies were detected only in mice that were inoculated with DNA vaccines encoding for VP4 and VP7. Efficacy of the vaccines was determined by challenge with 100 ID50 of homotypic rotavirus. Each of the three vaccines was effective in protecting mice against infection after rotavirus challenge as determined by reduction (P < .001) in virus excretion in mice receiving the DNA vaccines. These results demonstrate that DNA vaccination has potential as a new approach for control of rotavirus infections.

Surgical treatment of hepatolithiasis: long-term results

BACKGROUND

Hepatolithiasis is a common disease in East Asia and is prevalent in Taiwan. Surgical and nonsurgical procedures for management of hepatolithiasis have been discussed, but long-term follow-up results of surgical treatment of hepatolithiasis are rarely reported.

METHODS

We conducted a retrospective study of case records of patients with hepatolithiasis who underwent surgical or nonsurgical percutaneous transhepatic cholangioscopy treatment. Of 614 patients with hepatolithiasis seen between January 1984 and December 1988, 427 underwent follow-up after surgical (380) or percutaneous transhepatic cholangioscopy (47) treatment for 4 to 10 years and constituted the basis of this study.

RESULTS

Long-term results of 427 patients with hepatolithiasis after surgical and nonsurgical treatment within 4 to 10 years of follow-up were recurrent stone rate 29.6% (105 of 355), repeated operation 18.7% (80 of 427), secondary biliary cirrhosis 6.8% (29 of 427), late development of cholangiocarcinoma 2.8% (12 of 427), and mortality rate 10.3% (44 of 427). The patients with hepatectomy had a better quality of life (symptom-free) with a lower recurrent stone rate (9.5%), lower mortality rate (2.1%), and lower incidence of secondary biliary cirrhosis (2.1%) and cholangiocarcinoma (0%) than did the nonhepatectomy group (p < 0.01). The patients without residual stones after choledochoscopy had a better quality of life than did the residual stone group (p < 0.01).

CONCLUSIONS

Long-term follow-up study of hepatolithiasis after surgical treatment revealed a high recurrent stone rate (29.6%) that required repeated surgery and a high mortality rate (10.3%) resulting from repeated cholangitis, secondary biliary cirrhosis, and late development of cholangiocarcinoma. Patients who received hepatectomy or without residual stones after choledochoscopy had a good prognosis and quality of life.

Colored striae in obese children and adolescents

To document the characteristics of the striae in obese children and adolescents, 89 obese patients (56 males, 33 females) with a mean age of 9.6 +/- 3.0 years and range of 3 to 19 years who came to our pediatric nutrition clinic were studied. Obesity was defined as a weight-for-length index (WLI) above 1.2 (range 1.39 to 2.68). Striae were identified in 36 (40.4%) of the 89 patients. Generally, striae were present over both sides of the body symmetrically. Striae most prominently located on the thighs (73%), the arms (42%), and the abdomen (30%), less frequently on the back, buttocks, and over the knees. In about 40% of the patients, multiple sites were involved. There is no sex difference between striae and non-striae groups. Compared with the non-striae group, striae occurred in older age patients (11.5 vs 8.2 years, p = 0.0001), and more often in those with a longer duration of obesity (7.1 vs 5.0 years, p = 0.0002). A high prevalence of striae was found in more obese patients (WLI > 1.8). We conclude that striae might be associated with obesity, and the interpretation of striae as a cutaneous manifestation of obese children and adolescents should be considered.

Changes in intrahepatic portal hemodynamic in early stage hepatic abscesses

Color Doppler sonography was used to investigate the changes in intrahepatic portal hemodynamics in early stage hepatic abscesses (21 lesions). At time of patients' admission, 10 lesions measuring over 6 cm showed reverse flow from at least one of their corresponding segmental portal branches, but 11 lesions measuring 6 cm or less did not show this phenomenon. All portal branches with reverse flow eventually returned to a normal direction of flow after successful medication. In conclusion, a large early stage hepatic abscess may show temporary reverse portal flow on color imaging. Thus, a differential diagnosis of hepatic tumors with reverse portal flow should include early stage hepatic abscesses.

The status of serum hepatitis B virus DNA in HBSAG-positive hepatocellular carcinoma

To elucidate the status of serum hepatitis B virus (HBV) DNA in HBsAg-positive hepatocellular carcinoma (HCC), 100 type B chronic liver disease (CLD) patients and 19 HCC patients were studied. The positive rate of serum HBV DNA in HBeAg-positive CLD patients was significantly higher than that in HBeAg-negative CLD patients, and the correlation between the presence of serum HBV DNA and patients' age showed a negative trend. In contrast, the positive rates of serum HBV DNA in HCC patients were not related to the status of HBeAg and age, and the positive rate of serum HBV DNA in HBeAg-negative HCC patients was significantly higher than that in HBeAg-negative CLD patients. Nevertheless, the serum concentrations of HBV DNA in HCC patients were significantly lower than those in CLD patients. These results suggest that replication of HBV in HCC patients might differ from that in CLD patients, and that persistent low-level HBV replication might be related to the presence of HCC.

Transitional cell carcinoma of the bladder in the pediatric patient

PURPOSE

We report on 5 boys with transitional cell carcinoma of the bladder, describe the identifying characteristics, review the literature, and define the issues of diagnosis, treatment and followup in this rare disease in pediatric patients.

MATERIALS AND METHODS

Five boys 11 to 18 years old were identified with transitional cell carcinoma of the bladder. Preoperative imaging and urinary cytology were correlated with cystoscopic and biopsy findings.

RESULTS

In all patients evaluation was prompted by gross hematuria. Low grade lesions, definitive cystoscopic management and a low recurrence rate were uniform findings. Preoperative imaging identified the tumor in all cases and bladder ultrasound was the most sensitive scan with 4 of 4 cases identified.

CONCLUSIONS

While rare, transitional cell carcinoma of the bladder in children presents a challenge in diagnosis and followup since cystoscopy typically requires general anesthesia in this age group. Bladder ultrasound was found to be extremely sensitive in identifying lesions, and it may be a valuable and minimally invasive surveillance tool.

Characterization of the light-responsive promoter of rice chloroplast psbD-C operon and the sequence-specific DNA binding factor

The transcription of rice plastid psbD-psbC genes encoding photosystem II reaction center protein D2 and chlorophyll alpha-binding protein CP43 is closely regulated by light. To elucidate the sequence requirement for the light-responsive promoter of psbD-psbC operon, transcriptional analysis of the rice promoter was performed with deleted mutants and site-directed mutants in vitro. Deletion of -546 approximately -100 upstream sequences resulted in 4- to 5-fold decrease in the transcription rate. Further deletion of -99 approximately -40 conserved region of repeated sequences resulted in 2-fold decrease in the transcription rate. The core light-responsive promoter requires "-10" element but not "-35" element for accurate initiation of basal transcription. No downstream promoter element was found in the +4 approximately +111 region. The competitive gel-retardation experiments revealed the presence of DNA-binding protein in the rice chloroplasts, which interacts specifically with the -60 approximately -37 repeated sequences. Southwestern blot analysis further demonstrated that the binding factor is composed of 36-kDa polypeptide(s).

Longitudinal study of intrahepatic portal flow: a novel approach using Doppler technique

The present study investigates whether the application of the summation of portal blood flow (SPBF), measured from the left umbilical portion and the right anterior branch by Doppler, could be of use in the longitudinal study of intrahepatic portal flow or not. Forty-five subjects were divided into two groups. Group I subjects included males and post-menopausal females. Thirty-seven subjects (19 normal volunteers, 12 subjects with chronic hepatitis, six cirrhotics) were investigated by the more experienced doctor A at 9 day intervals for an intra-observer study. Among them, seven subjects (four normal volunteers, three with chronic hepatitis) were also investigated consecutively at 10 min apart by doctor B on days 1 and 10 for an interobserver study. Group II subjects included eight normal subjects with a regular menstrual cycle. They were investigated by doctor A during menstruation, mid-follicular, ovulatory and mid-luteal phases of the menstrual cycle to evaluate the possible impact of the menstrual cycle on SPBF measurement. The reproducibility of measurements was assessed by the coefficient of variation (CV) and the reproducibility coefficient. Data are expressed as mean +/- s.d. The CV of the SPBF for intra-observer and interobserver study were 4.88 +/- 3.36 and 4.19 +/- 2.53, respectively. All differences of SPBF were within their corresponding reproducibility limits. The results of SPBF measurements obtained from different phases of the menstrual cycle were variable. Only the comparison between the data obtained from mid-follicular and mid-luteal phases could demonstrate acceptable CV values (3.98 +/- 3.12%) and all the differences in SPBF measurements were within the repeatability limit. In conclusion, Doppler SPBF measurement may be useful in the longitudinal evaluation of intrahepatic portal flow changes.

Simple nephrectomy by retroperitoneoscope

Retroperitoneoscopic simple nephrectomy was successfully performed in 10 of 12 patients with nonfunctioning kidneys. The other two patients underwent traditional open surgery. The surgical procedures, technical pitfalls, surgical results and perisurgical complications of this simple retroperitoneoscopic approach are described. Retroperitoneoscopic nephrectomy is a viable alternative for simple nephrectomy and has the benefits of minimal invasiveness, more rapid convalescence and better quality of life for patients.

Dietary supplement of neosugar alters the fecal flora and decreases activities of some reductive enzymes in human subjects

The influence of dietary fructooligosaccharide (neosugar) on the fecal flora and activities of reductive enzymes was studied in 12 healthy, adult human subjects fed a controlled diet for 42 d and given 4 g neosugar/d between days 7 and 32. Fecal samples were collected before, during, and after supplementation with neosugar to enumerate total anaerobes, aerobes, bifidobacteria, and enterobacteria, and to assay for beta-glucuronidase, nitroreductase, and glycocholic acid hydroxylase. Although the controlled diet caused an increase in total anaerobes and bifidobacteria, the highest densities occurred during supplementation with neosugar. Total aerobes and enterobacteria were less affected by diet and neosugar. Neosugar caused beta-glucuronidase and glycocholic acid hydroxylase activities to decrease 75% and 90%, respectively; both increased after supplementation with neosugar was stopped. Nitroreductase activity declined 80% after the control diet was started, but was not affected by neosugar. These findings indicate that 4 g neosugar/d alters the fecal flora in a manner perceived as beneficial by decreasing activities of some reductive enzymes.