Intracerebral hemorrhage after liver transplantation

We report 5 patients with intracerebral hemorrhage after orthotopic liver transplantation (OLT) and identify the possible risk factors. Between November 1991 and April 1999, 75 adult patients received 77 orthotopic liver transplants at Queen Mary Hospital, Hong Kong. Five patients (6.5%) developed intracerebral hemorrhage postoperatively. Clinical and laboratory data were reviewed, and potential risk factors were analyzed. The 5 patients developed intracerebral hemorrhage within 40 days (range, 1 to 37 days; median, 4 days) after OLT. The mortality rate was 80% (4 of 5 patients). The intraoperative blood transfusion volume (median, 17,200 mL; range, 15,750 to 30,360 mL) administered to patients who developed intracerebral hemorrhage postoperatively was significantly greater than that (median, 6,990 mL; range, 1,840 to 22,680 mL) for patients without the complication (P =.0008). Massive intraoperative transfusion (>15,000 mL) was required in all 5 patients (100%) with intracerebral hemorrhage but only 9 of 72 patients (12.5%) in the other group (P =.0001). Four of 5 patients (80%) with intracerebral hemorrhage had intraoperative hypotension compared with 7 of 72 patients (9.7%) in the other group (P =.001). No significant difference was found in age, prothrombin time (PT), activated partial thromboplastin time (APTT), incidence of hypertension, bleeding at extracerebral sites, cyclosporine A neurotoxicity, thrombocytopenia, hemodialysis, and sepsis between the patients with and without intracerebral bleeding. However, the median cumulative score of coagulation parameters (PT, APTT, platelet count) was significantly greater in the group with than without intracerebral bleeding (median score, 3 v 1; P =.023). Intracerebral hemorrhage is 1 of the most disastrous complications after OLT. Intraoperative hypotension, massive intraoperative transfusion, and coagulopathy may be correlated with this complication.

Increased ventricular repolarization inhomogeneity during postural changes in patients with syndrome X

The interlead variation in QT interval (QT dispersion) can be used to assess regional inhomogeneity of ventricular repolarization under a variety of conditions, including stress. Patients with syndrome X may have increased sympathetic activity that could change QT interval regionally and give rise to an increase in QT dispersion under exercise testing. To test the hypothesis, 26 consecutive patients with syndrome X (group 1) were studied. Two additional groups matched in terms of age, sex, and left ventricular mass index consisting of 26 nonconsecutive patients with coronary artery disease (group 2) and 20 normal subjects (group 3) were studied for comparison. Standing induced a significantly higher increase of heart rate in group 1 than in groups 2 and 3 (7.5+/-6.0 vs 4.0+/-6.3 and 1.1+/-3.6 beats/min; p = 0.05 and 0.003, respectively). There were significant differences in QT dispersion between groups 1 and 2 on upright standing (48+/-12 vs 34+/-14 ms, p = 0.0003), but not at baseline (33+/-14 vs 38+/-11 ms, p = NS) or at peak exercise (38+/-9 vs 38+/-9 ms, p = NS). Results did not change when QTc dispersion was substituted for QT dispersion. From a conditional multivariate logistic regression analysis, the only independent predictor of occurrence of syndrome X on upright standing was QTc dispersion (odds ratio = 1.255, p = 0.01). Electrocardiographic QTc dispersion provides important clinical information. Patients with syndrome X had a higher increase of heart rate and QTc dispersion in response to standing from the supine position compared with patients with coronary artery disease and normal subjects.

Cytosine deaminase adenoviral vector and 5-fluorocytosine selectively reduce breast cancer cells 1 million-fold when they contaminate hematopoietic cells: a potential purging method for autologous transplantation

Ad.CMV-CD is a replication incompetent adenoviral vector carrying a cytomegalovirus (CMV)-driven transcription unit of the cytosine deaminase (CD) gene. The CD transcription unit in this vector catalyzes the deamination of the nontoxic pro-drug, 5-fluorocytosine (5-FC), thus converting it to the cytotoxic drug 5-fluorouracil (5-FU). This adenoviral vector prodrug activation system has been proposed for use in selectively sensitizing breast cancer cells, which may contaminate collections of autologous stem cells products from breast cancer patients, to the toxic effects of 5-FC, without damaging the reconstitutive capability of the normal hematopoietic cells. This system could conceivably kill even the nondividing breast cancer cells, because the levels of 5-FU generated by this system are 10 to 30 times that associated with systemic administration of 5-FU. The incorporation of 5-FU into mRNA at these high levels is sufficient to disrupt mRNA processing and protein synthesis so that even nondividing cells die of protein starvation. To test if the CD adenoviral vector sensitizes breast cancer cells to 5-FC, we exposed primary explants of normal human mammary epithelial cells (HMECs) and the established breast cancer cell (BCC) lines MCF-7 and MDA-MB-453 to the Ad.CMV-CD for 90 minutes. This produced a 100-fold sensitization of these epithelial cells to the effects of 48 hours of exposure to 5-FC. We next tested the selectivity of this system for BCC. When peripheral blood mononuclear cells (PBMCs), collected from cancer patients during the recovery phase from conventional dose chemotherapy-induced myelosuppression, were exposed to the Ad.CMV-CD for 90 minutes in serum-free conditions, little or no detectable conversion of 5-FC into 5-FU was seen even after 48 hours of exposure to high doses of 5-FC. In contrast, 70% of 5-FC was converted into the cytotoxic agent 5-FU when MCF-7 breast cancer cells (BCCs) were exposed to the same Ad.CMV-CD vector followed by 5-FC for 48 hours. All of the BCC lines tested were shown to be sensitive to infection by adenoviral vectors when exposed to a recombinant adenoviral vector containing the reporter gene betagalactosidase (Ad.CMV-betagal). In contrast, less than 1% of the CD34-selected cells and their more immature subsets, such as the CD34+CD38- or CD34(+)CD33- subpopulations, were positive for infection by the Ad.CMV-betagal vector, as judged by fluorescence-activated cell sorting (FACS) analysis, when exposed to the adenoviral vector under conditions that did not commit the early hematopoietic precursor cells to maturation. When artificial mixtures of hematopoietic cells and BCCs were exposed for 90 minutes to the Ad.CMV-CD vector and to 5-FC for 10 days or more, a greater than 1 million fold reduction in the number of BCCs, as measured by colony-limiting dilution assays, was observed. To test if the conditions were damaging for the hematopoietic reconstituting cells, marrow cells collected from 5-FU-treated male donor mice were incubated with the cytosine deaminase adenoviral vector and then exposed to 5-FC either for 4 days in vitro before transplantation or for 14 days immediately after transplantation in vivo. There was no significant decrease in the reconstituting capability of the male marrow cells, as measured by their persistence in female irradiated recipients for up to 6 months after transplantation. These observations suggest that adenovirus-mediated gene transfer of the Escherichia coli cytosine deaminase gene followed by exposure to the nontoxic pro-drug 5-FC may be a potential strategy to selectively reduce the level of contaminating BCCs in collections of hematopoietic cells used for autografts in breast cancer patients.

Mechanism of inhibition of MDA-MB-468 breast cancer cell growth by 2,3,7,8-tetrachlorodibenzo-p-dioxin

Treatment of estrogen receptor (ER)-negative MDA-MB-468 human breast cancer cells with 10 nM 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced formation of a nuclear aryl hydrocarbon (Ah) receptor complex as determined by ligand-binding and gel electrophoretic mobility shift assays. TCDD also induced CYP1A1-dependent activity in MDA-MB-468 cells, which represents the first ER-negative Ah receptor-positive human breast cancer cell line that has been identified. Treatment of this cell line with TCDD and related compounds also caused a 50% inhibition of cell growth, which resembled the growth inhibitory effects previously reported for epidermal growth factor (EGF). However, EGF expression is minimal in this cell line and is not induced by TCDD; moreover, EGF and TCDD induced a different pattern of oncogene expression and apoptosis in MDA-MB-468 cells. In contrast, TCDD caused a rapid and sustained induction of transforming growth factor alpha (TGF alpha) gene expression and secreted protein (nearly 2-fold); moreover, the growth-inhibitory effects of TCDD could be blocked by antibodies to the EGF receptor. In a separate experiment, it was shown that TGF alpha also inhibited growth of MDA-MB-468 cells. The results of this study indicate that the mechanism of growth inhibition of MDA-MB-468 cells by TCDD is due to induction of TGF alpha, which is a potent antimitogen in this cell breast cancer line.

Simultaneous team approach of a crown-lengthening procedure and an operative restoration: technique and long-term effect

Traditionally, crown-lengthening procedures to expose subgingival caries for operative restorative work are carried out in a two-stage approach. A disadvantage of this procedure is that the gingival margin associated with the treated tooth moves apically; this may create an esthetic problem. Resin-modified glass-ionomer cement has been demonstrated to have good biocompatibility with dental hard and soft tissues. Surgical and restorative procedures were combined at the same appointment in an effort to achieve a restoration with minimal change in the gingival margin. Four patients have been treated with this one-stage team approach and followed for 8 to 13 months. The clinical results demonstrated this team approach procedure is excellent for the dentition when esthetics is a consideration.

Effect of pretreatment counseling on discontinuation rates in Chinese women given depo-medroxyprogesterone acetate for contraception

The study examined the effect of pretreatment counseling upon discontinuation of 150 mg depo-medroxyprogesterone acetate (Depo-Provera (DMPA)), given for contraception. A total of 421 Chinese women participated, 204 receiving detailed structured pretreatment and ongoing counseling on the hormonal effects and probable side effects of DMPA and 217 receiving only routine counseling. The primary study endpoint was termination rate; secondary endpoints were frequency of medical events and reasons for termination. Study termination rates were significantly lower in the intensive structured counseling group than in the routine counseling group. At one year, the total cumulative termination rates were 11% (23/204) and 42% (92/217), respectively (p < 0.0001). The most common reasons for terminating DMPA were menstrual changes. No pregnancy, serious or unexpected medical events were reported, nor were statistically or clinically significant changes in vital signs observed. We conclude that pretreatment counseling on expected side effects increases the acceptability of DMPA.

Apoptosis and expression of Bcl-2 after compression trauma to rat spinal cord

We have evaluated by in situ nick-end labeling the presence of apoptotic cells in the spinal cord of rats with compression injury at the level of Th8-9 of mild, moderate, and severe degrees resulting in no neurologic deficit, reversible paraparesis, and paraplegia, respectively. Rats with compression injury surviving 4 or 9 days showed apoptotic glial cells in the longitudinal tracts of the Th8-9, the cranial Th7, and the caudal Th10 segments. The apoptotic cells were most frequently observed in Th7. They did not express glial fibrillar acidic protein (GFAP) and their morphology was compatible with that of oligodendrocytes. Neurons of the gray matter did not present signs of apoptosis. In addition, we studied the immunohistochemical expression of Bcl-2, an endogenous inhibitor of apoptosis. Compression induced Bcl-2 immunoreactivity in axons of the long tracts, particularly after moderate and severe compression and 1-day survival. Neurons of dorsal root ganglia were immunoreactive but the neurons of the spinal cord were unstained. The accumulation, presumably caused by arrested axonal transport in sensory pathways, was absent in rats surviving 9 days. In conclusion, compression trauma to rat spinal cord induces signs of apoptosis in glial cells, presumably oligodendrocytes of the long tracts. This may induce delayed myelin degeneration after trauma to the spinal cord. Bcl-2 does not seem to be upregulated in oligodendrocytes.

Effect of transient expression of the oestrogen receptor on constitutive and inducible CYP1A1 in Hs578T human breast cancer cells

Hs578T human breast cancer cells are an oestrogen receptor (ER)-negative cell line. Treatment of these cells with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) resulted in formation of a 6.9 S nuclear aryl hydrocarbon (Ah) receptor complex, which bound to a [32P]dioxin-responsive element in a gel electrophoretic mobility shift assay. However, TCDD does not induce CYP1A1 gene expression or chloramphenicol acetyl transferase (CAT) activity in cells transiently transfected with pRNH11c or pMCAT5.12, which are Ah-responsive plasmids derived from the 5'-flanking region of the human and murine CYP1A1 genes respectively. Restoration of Ah responsiveness was investigated by co-transfecting Hs578T cells with pRNH11c or pMCAT5.12 and plasmids that express the ER (hER), Ah receptor (AhR) and AhR nuclear translocator (Arnt) proteins. ER expression resulted in significantly increased basal CAT activity; however, TCDD did not induce CAT activity in the transiently transfected cells. Expression of the AhR or Arnt proteins did not alter basal or inducible CAT activity. Expression of N- or C-terminal truncated ER in Hs578T resulted in differential regulation of Ah responsiveness. In Hs578T cells transiently expressing the ER, which contains C-terminal deletions (amino acids 282-595), basal CAT activity was also increased; however, Ah responsiveness was not restored. In contrast, transient expression of N-terminal-deleted (amino acids 1-178) ER resulted in a marked decrease in basal CAT activity but a restoration of Ah responsiveness. These results suggest that basal and inducible CAT activity in Hs578T cells transiently transfected with pRNH11c is modulated differentially by ER domains that are present in the N- and C-terminal regions of the ER.

Home healthcare nurses' knowledge and attitudes towards suicide

This study identified home healthcare nurses' knowledge of and attitudes toward suicide in the elderly. Three questionnaires and a demographic data sheet were distributed to nurses who work in three community health agencies. Findings showed that subjects knew some of the signs of potential suicide. Most subjects had a middle to high degree of sympathy and empathy toward elderly persons who attempted suicide, but disagreed wit. h their suicidal actions. There was no significant relationship between knowledge of the signs of potential suicide and attitudes toward suicide in the elderly.

Testing human hair for drugs of abuse. IV. Environmental cocaine contamination and washing effects

Active cocaine use results in sequestration of parent drug in hair. In addition, hair has unique physicochemical properties that permit absorption of cocaine from the environment. When hair is tested for evidence of cocaine, it is important to consider whether the positive test resulted from active drug use or environmental contamination. In a series of laboratory experiments, it was found that exposure of 'cut' hair to cocaine vapor ('crack' smoke) and to aqueous solutions of cocaine hydrochloride resulted in significant contamination of hair samples. Similar results were obtained with two subjects who were exposed to cocaine vapor in an unventilated room. The amount of contamination adsorbed by hair depended upon both time and extent of exposure. Washing the hair samples with methanol removed > 70% of the cocaine contaminant after cocaine vapor exposure, but was less effective (< 50%) following contamination with aqueous cocaine. Shampoo treatment cycles (overnight soaking) progressively removed increasing amounts of cocaine from the contaminated hair, but residual cocaine remained after 10 cycles. Studies were also performed to determine the usefulness of benzoylecgonine as a marker of active cocaine administration. Small amounts of benzoylecgonine (ca. 1 ng/mg) were formed in hair as a result of environmental contamination with cocaine. Also, it was found that benzoylecgonine could be adsorbed from illicit cocaine contaminated with benzoylecgonine. It was concluded that positive hair test results should be interpreted cautiously due to the possibility of environmental contamination from cocaine and related constituents.

Simultaneous assay of cocaine, heroin and metabolites in hair, plasma, saliva and urine by gas chromatography-mass spectrometry

As part of an ongoing research program on the development of drug detection methodology, we developed an assay for the simultaneous measurement of cocaine, heroin and metabolites in plasma, saliva, urine and hair by solid-phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS). The analytes that could be measured by this assay were the following: anhydroecgonine methyl ester; ecgonine methyl ester;. ecgonine ethyl ester; cocaine; cocaethylene; benzoylecgonine; cocaethylene; norcocaethylene; benzoylnorecgonine; codeine; morphine; norcodeine; 6-acetylmorphine; normorphine; and heroin. Liquid specimens were diluted, filtered and then extracted by SPE. Additional handling steps were necessary for the analysis of hair samples. An initial wash procedure was utilized to remove surface contaminants. Washed hair samples were extracted with methanol overnight at 40 degrees C. Both wash and extract fractions were collected, evaporated and purified by SPE. All extracts were evaporated, derivatized with N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS) and analyzed by GC-MS. The limit of detection (LOD) for cocaine, heroin and metabolites in biological specimens was approximately 1 ng/ml with the exception of norcodeine, normorphine and benzoylnorecgonine (LOD = 5 ng/ml). The LOD for cocaine, heroin and metabolites in hair was approximately 0.1 ng/mg of hair with the exception of norcodeine (LOD = 0.3 ng/mg) and normorphine and benzoylnorecgonine (LOD = 0.5 ng/mg). Coefficients of variation ranged from 3 to 26.5% in the hair assay. This assay has been successfully utilized in research on the disposition of cocaine, heroin and metabolites in hair, plasma, saliva and urine and in treatment studies.

[Localization of apoptosis-antagonizing bcl-2 translated product in Hodgkin's disease]

We applied more sensitive immunohistochemical method, i.e. multilayered PAP, to investigate the expression and distribution of apoptosis-antagonizing gene bcl-2 in Hodgkin's disease (HD), bcl-2-positive Reed-Sternberg (RS) cells were found in 7 of 21 (33%) of HD, and 2 of 7 (mixed cellularity) accompanied by a lot of reactive lymphoid follicles, the germinal centers of which were also positive for bcl-2. In contrast, in 4 cases of inflammatory lymphoid follicular hyperplasia as positive controls, the mantle zones rich in long-lived B cells were strongly positive stained with bcl-2 antibody, whereas germinal centers were negative. Thus, our data indicate that overexpressed bcl-2 gene-mediated apoptosis impairment is strongly associated with pathogenesis of HD.

Immunohistochemical demonstration of CCAAT/enhancer binding protein (C/EBP) in human liver tissues of various origin

C/EBP is a sequence-specific DNA-binding protein. In order to identify its distribution and localization, immunohistochemical technique (ABC method) was done using anti-C/EBP polypeptide antibodies 1103#, 425# in liver specimens from 20 normal adults, 5 neonates, 6 patients with hepatitis, 25 with liver cirrhosis, 80 with hepatocellular carcinoma (40 cases were associated with surrounding nontumorous tissues) and 26 patients with cholangiocarcinoma (15 cases were associated with surrounding nontumorous tissues). The results showed that C/EBP was diffusely distributed in nuclei and cytoplasm of differentiated liver cells and very low or undetectable in liver cancer cells. The manifestation of C/EBP correlated with degree of differentiation of tumour cells, and was obviously weaker than that in surrounding nontumorous tissues. C/EBP positive staining has also been found in regenerating epithelial cells of bile ductules. The results suggested that C/EBP should play an important role in establishing and maintaining the differentiation of liver cells.

[In situ PCR-gene hybridization method for detecting mycobacterium tuberculosis in tissue specimens]

The authors combined the technique of polymerase chain reaction (PCR) with hybridization in situ, and find the method is better, quicker and more sensitive for detecting a trace of bacterial DNA, especially for observing the relation between the lesion and the peripheral tissue, the method is more simple and no radioactive pollution. It seems to be suitable for detection on samples from autopsy, biopsy and smears. We suppose the method might have a prospect for clinical diagnosis.

[Surgical treatment of atherosclerotic occlusion of lower extremities]

27 patients with atherosclerotic occlusion of lower extremities were admitted from January 1988 to December 1992. Those patients underwent various kinds of bypass operations, with an effective rate of 86.8%. Some factors influencing the operative effect are discussed.

The occurrence of cocaine, heroin and metabolites in hair of drug abusers

The analysis of hair for drugs of abuse reveals information regarding past drug exposure. We developed methods for washing, extraction and analysis of hair samples for cocaine, heroin and metabolites. Twenty paired head- and arm-hair samples, collected from known heroin/cocaine abusers, were analyzed with a new comprehensive GC/MS assay for cocaine, heroin and metabolites. Cocaine and 6-acetylmorphine (6-AM) were the major analytes present in both head- and arm-hair samples. Cocaine was detected in all head- and 17 arm-hair samples. The concentration of cocaine found was 4-760 ng/10 mg in head hair and 0-1090 ng/10 mg in arm hair. Less benzoylecgonine was present in a concentration range of 0-158 ng/10 mg of head hair and 0-125 ng/10 mg of arm hair. Heroin was found in only 2 head-hair samples, whereas 6-AM was present in 14 head and 6 arm-hair samples. The concentration of 6-AM was 0-8 ng/10 mg in head hair and 0-31 ng/10 mg in arm hair. Morphine was present in 3 head-hair samples in a range of 2-9 ng/10 mg and was not detected in arm-hair samples. When results were compared by groups (head hair versus arm hair, Caucasoid versus Africoid), only two significant differences were found. Cocaine concentrations in both head and arm hair were significantly (P < 0.05) higher in the Africoid group than in the Caucasoid group. The reasons for these differences were not readily apparent, but could have been due to differences in the level of cocaine use or to ethnic differences in the deposition of drug in hair.

Biosynthesis of ecdysteroid hormones by crustacean Y-organs: conversion of cholesterol to 7-dehydrocholesterol is suppressed by a steroid 5 alpha-reductase inhibitor

A pair of glands (Y-organs) in crustaceans synthesize and secrete ecdysteroid hormones; the obligate precursor for synthesis is circulating cholesterol. Ecdysteroid output by the Y-organs is regulated negatively by an eyestalk neurosecretory peptide, molt-inhibiting hormone (MIH). The question was addressed, does MIH suppress ecdysteroid synthesis by decreasing cholesterol supply (uptake) or its utilization or both? Experiments were conducted with Y-organs in vitro from the crab, Menippe mercenaria, in the presence of labeled cholesterol, with or without the steroid 5 alpha-reductase inhibitor, L-645390 (Merck). Other experiments superimposed the presence or absence of eyestalk extract containing MIH activity. L-645390 greatly depressed incorporation of cholesterol into an early intermediate, 7-dehydrocholesterol and into secreted ecdysteroids. At the same time, cholesterol accumulated in the Y-organs, to levels significantly higher than in untreated controls. MIH alone depressed both cholesterol uptake and incorporation. MIH together with L-645390 produced the greatest depression of cholesterol incorporation while also preventing the cholesterol accumulation seen with L-645390 alone. These results indicate that cholesterol uptake and its metabolic utilization in Y-organs are separable events representing separate sites of regulation by MIH.

Immunoassay evidence for fentanyl in hair of surgery patients

Head hair samples obtained from surgery patients who received fentanyl during anesthesia were analyzed by immunoassay for the presence of fentanyl. Thirteen hair samples were collected from patients following intravenous administration of 1-6 mg of fentanyl. Additional hair samples were collected following the administration of 0.18 and 0.38 mg of sufentanil to 2 patients. The elapsed time after drug administration for all patients ranged from 7 to 273 days. Twenty control hair samples also were collected from staff members who reported no surgery or anesthesia during the previous year. All samples were initially washed with methanol, followed by extraction with methanol and reconstitution in citrate buffer. Analysis of wash and extract fractions was performed by radioimmunoassay (Coat-A-Count Fentanyl assay). Segmental analysis was performed on the surgery patients' hair samples. Eight of the fentanyl patients' hair samples contained fentanyl concentrations (equivalents) of 0.13-0.48 ng/10 mg of hair in the 'root' end. Fentanyl concentrations in the 'tip' segment were lower than those found in the 'root' segment with the exception of 1 subject whose hair sample had been collected only 7 days after surgery. The remaining 5 patients had fentanyl concentrations similar to those determined for the control subjects hair samples (0-0.08 ng/10 mg, n = 19). No correlation between hair fentanyl concentration and administered dose was found for the 13 fentanyl subjects. Both sufentanil subjects' hair samples tested negative. One control subject who had experienced environmental exposure to fentanyl had a fentanyl concentration of 0.29 ng/10 mg in the extract and 0.63 ng/10 mg in the wash fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

[Expression of five different antigens of HBV in human intrahepatic cholangiocarcinoma and cholangiohepatocarcinoma]

Surgical specimens of 20 cases of human intrahepatic cholangiocarcinoma (n = 12) and cholangiohepatocarcinoma (n = 8) were studied immunohistochemically by ABC technique for HBxAg, pre-S1 and pre-S2 and by PAP method for HBsAg and HBcAg. The neighboring liver tissues with chronic hepatitis or cirrhosis surrounding the tumor were also examined in 19 cases. Of the cancerous tissues, 15 were positive for HBxAg (75%), 8 positive for pre-S1 and pre-S2 (40%), respectively and 2 for HBsAg (10%). Sixteen of 19 liver tissues surrounding the tumor were also positive for HBxAg (84.2%), 9 for pre-S1 and pre-S2 each (47.4%), 6 for HBsAg and HBcAg each (31.6%). The results suggest that a close relationship exists between cholangiocarcinoma and cholangiohepatocarcinoma and hepatitis B virus infection. The HBxAg might play an important role in the pathogenesis of cholangiocarcinoma.

Formation of ecdysteroids by Y-organs of the crab, Menippe mercenaria. I. Biosynthesis of 7-dehydrocholesterol in vivo

Y-organs of the xanthid crab, Menippe mercenaria, secrete ecdysteroid hormones in vitro, apparently both 3-dehydroecdysone and 25-deoxyecdysone. Studies were initiated on the biosynthetic path(s), in which cholesterol is converted to these ecdysteroids. Crabs were injected with [3H]cholesterol. Y-organs and hemolymph were removed 12 hr later and extracted directly and the extracts were analyzed by HPLC. Both polar and nonpolar sterols were surveyed. The only metabolite of cholesterol detectable in Y-organs was 7-dehydrocholesterol (identified by mass spectrometry). The total amount of 7-dehydrocholesterol and the amount that was labeled were generally greater than for cholesterol and were higher in Y-organs from de-eyestalked crabs than in those from intact crabs. Subcellular fractionation of the Y-organs showed that over 70% of total radioactivity was in cholesterol and 7-dehydrocholesterol of mitochondria and microsomes, distributed about equally between the two organellar fractions. In hemolymph, the only nonpolar sterols present were cholesterol and 7-dehydrocholesterol; the concentration ratio was 20:1. However, 7-dehydrocholesterol was not significantly labeled. Analyses of polar compounds revealed two prominent, uv-absorbing ecdysteroids which coeluted with the authentic standards, 3-dehydro-20-hydroxyecdysone and 25-deoxy-20-hydroxyecdysone (ponasterone A). The radioactivity profile showed, in addition, a third prominent peak that corresponded in retention time with 3-dehydroecdysone. These results indicate that the Y-organs in vivo form 7-dehydrocholesterol from cholesterol and convert the latter to secretion products without accumulation of other intermediates. At least two ecdysteroids are secreted and appear to be converted peripherally in this crab to their respective 20-hydroxy derivatives.