BDNF regulation of androgen receptor expression in axotomized SNB motoneurons of adult male rats

Brain-derived neurotrophic factor (BDNF) prevents the axotomy-induced loss of androgen receptor-like immunoreactivity (AR-LI) in the spinal nucleus of the bulbocavernosus (SNB) motoneurons of adult male rats. In this report, we investigated the dose-response effect of BDNF on androgen receptor expression in axotomized SNB motoneurons, and examined whether delayed application of BDNF to the cut SNB axons can completely reverse the axotomy-induced loss of androgen receptor expression. We also used autoradiography to test whether axotomy decreases the ability of SNB motoneurons to accumulate androgens. SNB motoneurons were axotomized bilaterally and BDNF or PBS was applied to the proximal ends of the axons. The percentage of SNB motoneurons expressing medium or high AR-LI was the major measure of androgen receptor expression. AR-LI was significantly higher on the BDNF-treated side than on the contralateral side treated with phosphate-buffered saline (PBS) for all three doses of BDNF (1.45, 2.9, and 5.8 mg/ml) and was higher than in rats treated bilaterally with PBS. Moreover, AR-LI at the highest dose of BDNF was not different from that in intact SNB motoneurons. Delayed application of BDNF to the axotomized SNB motoneurons restored the AR-LI to the intact level. The AR-LI decreased by axotomy started to increase significantly 4 days after BDNF application and returned to the intact level by 10 days. Furthermore, axotomy significantly decreased the percentage of SNB motoneurons to accumulate tritiated testosterone or its metabolites. In conclusion, our data demonstrate that BDNF completely prevents and reverses the axotomy-induced loss of AR-LI. Moreover, decrease of AR-LI by axotomy reflects the decrease in the ability of SNB motoneurons to accumulate androgens.

Use of novel plasmid constructs to demonstrate fludarabine triphosphate inhibition of nucleotide excision repair of a site-specific 1,2-d(GpG) intrastrand cisplatin adduct

We previously showed that fludarabine triphosphate (F-ara-ATP) acts as a potent inhibitor of nucleotide excision repair (NER). To determine how F-ara-ATP inhibits NER, we designed closed circular DNA duplexes, each containing a site-specific d(GpG) cisplatin adduct, as the substrate for an in vitro repair assay. We used the assay to determine the effects of F-ara-ATP on the incision, repair synthesis, and ligation steps in the NER process. A closed circular DNA duplex, pSSA, was first constructed by inserting an 87-bp oligonucleotide into pGEM-7Zf(+), from which a single-stranded plasmid (pTDS) was derived. The 87-bp insert included two potential repair patches; each contained a d(GpG) site flanked by unique sequences 22 nucleotides upstream and 6 nucleotides downstream so that four dAMP sites were strategically placed in patch 1 but were absent from patch 2. Each duplex substrate was then synthesized by annealing a unique primer containing a platinated and 32P-end-labeled oligonucleotide to the pTDS template, which was then converted to a duplex through polymerization and ligation. At 50 microM, F-ara-ATP inhibited repair synthesis; F-ara-ATP also inhibited incision and ligation, but only at concentrations of 200 microM and above. Chemical DNA sequencing of the repair patch revealed that F-ara-ATP induced the formation of a truncated repair patch in which DNA polymerization stopped one nucleotide before the first installed dAMP site - a potential site for F-ara-ATP's incorporation. In contrast, truncation of a repair patch was not detectable when the repair patch contained no dAMP. Taken together, the results suggest that F-ara-ATP induced patch truncation by self-incorporation and the incorporated F-ara-AMP was subsequently excised, presumably by polymerase-associated exonuclease activity. We conclude that F-ara-ATP blocks the NER process by strongly inhibiting DNA repair synthesis as well as by less strongly inhibiting incision and ligation. Our approach of designing plasmid constructs that contain sequence-specific repair patches with a strategically placed 32P label may provide a powerful tool for dissecting the mechanism of NER inhibition not only for F-ara-ATP but also for other NER inhibitors.

Efficacy of a pure compound H1-A extracted from Cordyceps sinensis on autoimmune disease of MRL lpr/lpr mice

Cordyceps sinensis (CS) is a traditional Chinese medicine with immunomodulatory effect and is effective in improving the survival of lupus mice. In the present study we isolated a pure compound (H1-A) from CS and investigated its effect on inhibiting autoimmune disease progression in MRL Ipr/Ipr mice. Our results demonstrated that MRL Ipr/Ipr mice treated daily with H1-A (40 microg/kg/d orally) for 8 weeks had a progressive reduction in anti-ds-DNA production (optical density value decreased from 0.172 +/- 0.009 to 0.112 +/- 0.015) when compared with the control group (optical density value increased from 0.141 +/- 0.036 to 0.198 +/- 0.047). In clinical presentation, the treated group had a reduction in lymphadenopathy, a delayed progression of proteinuria, and an improvement in kidney function. Histologic analysis of kidney tissue indicated that H 1-A could inhibit the mesangial proliferation that was evident in lupus nephritis. However, there was no significant change in immune complex deposition. The studies reveal that the pure compound (H1-A) may be potentially useful for treating systemic lupus erythematosus in human patients, and they provide some questions for further investigation of the pathogenesis of systemic lupus erythematosus and lupus nephritis.

Cell cycle checkpoint abrogator UCN-01 inhibits DNA repair: association with attenuation of the interaction of XPA and ERCC1 nucleotide excision repair proteins

UCN-01, an anticancer agent currently in Phase I clinical trials, has been found to potentiate the cytotoxicity of cisplatin (CDDP). Because mammalian cells remove CDDP-induced DNA adducts through the nucleotide excision repair (NER) pathway, we determined the effects of UCN-01 on NER by measuring its effects on the interaction of the repair factors XPA and ERCC1 and the phosphorylation/dephosphorylation of the repair proteins. The repair activity, as measured by an in vitro repair synthesis assay and an in vivo host-cell reactivation assay using A549 cells, was significantly reduced. Although expression of XPA and ERCC1 proteins was elevated in cells exposed to UCN-01, the treatment resulted in a decreased ERCC1 level in the Triton X-100-insoluble fraction of cell lysates. A pull-down assay using the MBP-XPA fusion protein showed a significant reduction in the binding of ERCC1 to XPA in nuclear extracts from UCN-01-treated cells compared with untreated cells, suggesting that UCN-01 reduced the XPA-ERCC1 interaction. Consistent with these data, lower repair incision activity was found in the cell extracts from UCN-01-treated cells. In vitro phosphorylation revealed that UCN-01 had no effect on the phosphorylation/dephosphorylation status of either XPA or ERCC1; however, UCN-01 caused dephosphorylation of an unidentified XPA-bound protein with an apparent molecular mass of 52 kDa. Taken together, these data demonstrate the NER-inhibitory action of UCN-01, which is associated with the inhibition of the XPA-ERCC1 interaction by UCN-01 and with the effect of UCN-01 on the phosphorylation/dephosphorylation of an XPA-bound, 52-kDa protein, the identity of which remains to be determined.

Tissue factor pathway inhibitor attenuates procoagulant activity and upregulation of tissue factor at the site of balloon-induced arterial injury in pigs

Intravenous infusion of recombinant tissue factor pathway inhibitor (rTFPI) for 24 hours decreases neointimal thickening and luminal stenosis 1 month after balloon-induced injury to the carotid arteries in minipigs. This study was designed to determine whether the effect of rTFPI is accounted for by early decreases in procoagulant activity and thrombosis on the injured vessel wall. Vascular injury was induced by balloon hyperinflations in both carotid arteries of anesthetized pigs given no anticoagulant as a control (n=16), an intravenous infusion for 24 hours of rTFPI (0.5 mg/kg bolus and 25 microg. kg(-1). min(-1), n=14), or an intravenous infusion of unfractionated heparin (100 U. kg(-1). h(-1), n=19). Accumulation of radiolabeled autologous platelets was markedly decreased over 24 hours on injured arteries from animals given rTFPI (0.6x10(6)/cm(2)) compared with controls (2.5x10(6)/cm(2), P=0.0004). Deposition of radiolabeled fibrin was also decreased in rTFPI-treated animals (269+/-266 microg/cm(2)) compared with controls (2389+/-1673 microg/cm(2), P=0.04). Similar effects were observed with heparin. However, factor Xa activity, assayed after 24 hours by incubation of the injured arterial segments with the chromogenic substrate S-2222, was decreased more markedly on arteries from rTFPI-treated animals (0.14+/-0.13 OD) than those from heparin-treated animals (0.29+/-0.18 OD) compared with controls (0. 47+/-0.24 OD, P=0.0007). In addition, arteries from rTFPI-treated animals showed a 4-fold lower induction of tissue factor protein compared with controls (P=0.0002). Attenuation of procoagulant activity and tissue factor-mediated thrombin generation in response to injury may account for the promising results with rTFPI in the porcine angioplasty model.

Comparison of methods for local delivery of tissue factor pathway inhibitor to balloon-injured arteries in rabbits

BACKGROUND

Prolonged intravenous infusions of recombinant tissue factor pathway inhibitor (rTFPI) have been shown to attenuate markedly neointimal formation and stenosis after balloon-induced injury to the carotid arteries in minipigs.

DESIGN

Because local delivery of rTFPI to the injury site would be clinically advantageous, we designed this study to compare the local delivery and retention of rTFPI in balloon-injured arteries using three catheter-based systems.

METHODS

Similar amounts (range 3-4.5 mg) of a mixture of 125I-labeled and unlabeled rTFPI were delivered by either passive diffusion at moderate pressure (5 x 10(5) Pa with the LocalMed InfusaSleeve, or 4 x 10(5) Pa with the SciMed Dispatch device), or facilitated diffusion combining lower pressure (2 x 10(5) Pa) and electrical current (3.5 mA/cm2; e-MED, iontophoresis) to balloon-injured carotid arteries in anesthetized rabbits.

RESULTS

Comparable amounts of rTFPI were retained on the injured vessels immediately after delivery (t = 0) with the LocalMed (628 +/- 68 micrograms/g per cm2, n = 4), SciMed (522 +/- 167 micrograms/g per cm2, n = 4), and e-MED (497 +/- 142 micrograms/g per cm2, n = 4) catheters (NS). However, rTFPI was decreased by 37% after 24 h compared with t = 0 (P < 0.02) in the e-MED group, but was increased 1.5-fold (P = 0.02) and 1.3-fold in the SciMed and LocalMed groups, respectively, presumably because of redistribution of rTFPI from remote endothelial or perivascular sites. Retention of rTFPI was six to nine times higher for injured compared with non-injured arteries, and persisted for at least 48 h after delivery with the LocalMed catheter.

CONCLUSIONS

Sustained, marked retention of rTFPI delivered locally at the site of balloon-induced arterial injury appears to result from catheter-based systems that use passive diffusion at moderate pressure.

Multiple myeloma presenting with a paraspinal tumor and malignant effusion: case report

We describe a patient with multiple myeloma which presented as a thoracic paraspinal tumor and myelomatous pleural effusion. He had manifested a gradual onset of upper back pain with radiation to the left chest wall for 3 months. A radiographic examination showed left pleural effusion and a paraspinal tumor with rib destruction at the--left T5-6 level. Laboratory data showed anemia and a reversed serum albumin to globulin ratio. Protein electrophoresis and immunoelectrophoresis showed a monoclonal IgG-lambda chain component in the serum, urine, and pleural effusion fluid. Ultrasound-guided transthoracic mass biopsy and thoracentesis were performed for diagnosis. Biopsy of the thoracic tumor showed a solid mass composed of immature plasma cells. The pleural effusion fluid contained numerous immature plasma cells. An immunophenotype study of the pleural effusion fluid revealed monoclonal plasma cells, compatible with malignant pleural effusion. A specimen of bone marrow was interpreted as typical for plasma cell myeloma. Local radiotherapy and chemotherapy with melphalan and prednisolone resulted in good partial remission with a stable condition. Later, however, the disease flared up and hyperviscosity syndrome developed with epistaxis and retinal hemorrhage. He died of sepsis about 15 months after the initial diagnosis.

IgG subclass/IgM ratio and response to therapy in focal segmental glomerulonecrosis

Focal segmental glomerulosclerosis (FSGS) is relatively steroid resistant and no clinical or histological marker can predict the response to therapy. To investigate the role of serum immunoglobulin subclass/IgM in predicting the response to therapy in FSGS, serum concentrations of total IgG, IgG subclasses, and the ratio of serum IgG subclasses to total IgG (% IgG subclass) were measured in 27 children during the acute nephrotic state. Prednisolone, cyclophosphamide, and Persantine (dipyridamole) were given for 12 weeks. We divided the patients into good responders or poor responders according to clinical response. The clinical and nephrotic status were similar in both groups. Fourteen patients were good responders with higher serum IgGI/IgM than that of non-responders (4.00+/-0.67 vs. 1.61+/-0.20, P<0.05). There was no significant difference in IgG2/IgM between these two groups. These results suggest that higher serum IgGI/IgM ratios may be associated with a better clinical response. These changes may reflect dysregulation of immunoglobulin class switching in patients with FSGS.

Clinical aspects of the hemolytic uremic syndrome

Hemolytic uremic syndrome (HUS) can be clinically classified into two types: typical cases with a diarrheal prodrome of association with E. coli O157, and atypical cases without antecedent diarrhea. However, HUS is not common in Taiwan. To evaluate the clinical course, complications and outcome of HUS in children, and to identify the risk factors for mortality, retrospectively, seven cases of HUS in our hospital in the past 6 years were studied. Six of them were boys, and one was a girl. Their ages ranged from 0.67 to 3 years. None of them were preceded by diarrheal prodrome. Acute renal failure, hypertension and liver involvement were noted in all cases. Stroke and seizure developed in three of the cases with sequelae. Two cases progressed into end-stage renal disease (ESRD). One case developed acute respiratory distress syndrome (ARDS). Two cases (28.5%) expired. ESRD especially associated with ARDS was highly related to mortality.

Influence of male-related stimuli on female postejaculatory refractory period in rats

Female rats "pace" their sexual contacts with the male when tested in situations where they can escape from the male during copulation. The type and quality of vaginocervical stimulation that the females receive during copulation influences their pacing behavior. This study investigated the effect of several male-related stimuli on the female's postejaculatory refractory period (PER). Females were tested in a two-compartment test chamber from which they could escape the male through one of four openings along the bottom of the barrier separating the two compartments. Experiment 1 examined the influence of the seminal plug, the penile cup, and prostate secretions on the female's PER. Results showed that neither the seminal plug, the penile cup, nor prostate secretions contributed to the female's PER. Experiment 2 investigated the relation of pre-ejaculatory intromission frequency, ejaculation duration, and the number of pelvic thrusts during ejaculation to the female's PER. Results indicated that pre-ejaculatory intromission frequency and ejaculation duration but not the number of pelvic thrusts during ejaculation were significantly correlated with the female's PER. In addition, pre-ejaculatory intromission frequency was significantly correlated with ejaculation duration. Partial correlation analysis suggested that pre-ejaculatory intromission frequency affected ejaculation duration which, in turn, influenced the female's PER. This finding was further supported by the evidence that ejaculation duration and the female's PER were significantly shorter in tests in which the male ejaculated on the first or second intromission.

Clinical efficacy of cyclosporin a neoral in the treatment of paediatric lupus nephritis with heavy proteinuria

Cyclosporin A (CsA) was introduced in recent years for the treatment of lupus nephritis in patients with steroid resistance or in those with severe corticosteroid toxicity. Our previous study on paediatric patients showed that Neoral (a new microemulsion formulation) had better bioavailability than CsA capsules. To evaluate the clinical efficacy of Neoral in children with lupus nephritis compared with conventional therapy, we performed an open randomized study on 40 children, ranging from 9 to 14 yr old, with class III-V lupus nephritis and heavy proteinuria. They were randomly assigned to either Neoral (5 mg/kg/day), administered q.12.h, or prednisolone (2 mg/kg/day) plus cyclophosphamide (2 mg/kg/day) for 1 yr. Both groups showed a significant decrease in proteinuria (Neoral: 4.62 +/- 1.93 to 0.35 +/- 0.29 g/day, P < 0.05; prednisolone plus cyclophosphamide: 4.52 +/- 1.86 to 0.62 +/- 0.21 g/day, P < 0.01). The CH50 haemolytic assay titre decreased after 1 yr of Neoral treatment (26.5 +/- 0.9 to 21.4 +/- 2.2 U/ml, P < 0.05). Serum C3 and anti-double-stranded (ds) DNA antibody levels also fell with Neoral (C3: 86.2 +/- 6.8 to 76.3 +/- 4.5 mg/dl; anti-ds DNA antibodies: 14.1 +/- 3.2 to 8.2 +/- 1.4 IU/ml, P < 0.05). The Neoral group had a significant increase in growth rate over the prednisolone plus cyclophosphamide group (8.2 +/- 1.1 cm/yr vs 2.7 +/- 0.6 cm/yr, P < 0.01) with improvement of growth status. During the study period, patients tolerated Neoral well with no significant changes in renal function, liver function or lipid profile. Our study implies that Neoral appears to be effective in suppressing proteinuria. Neoral should be regarded as being adjunctive therapy, perhaps with a steroid-sparing effect, in paediatric lupus nephritis. However, its long-term use awaits further studies.

Persistent transforming growth factor beta 1 expression may predict peritoneal fibrosis in CAPD patients with frequent peritonitis occurrence

The efficiency of continuous ambulatory peritoneal dialysis (CAPD) depends on the permeability of the peritoneal membrane. Peritoneal fibrosis (PF) causes the loss of dialytic function. Several studies have indicated that PF is closely related to the proliferation of peritoneal fibroblasts and the deposition of extracellular matrix (ECM). Transforming growth factor beta 1 (TGF beta 1) plays a major role in stimulating ECM deposition. Frequent peritonitis occurrence may cause persistent TGF beta 1 mRNA expression. In an attempt to search for a factor related to PF, we designed a longitudinal study to measure TGF beta 1 levels in dialysate and TGF beta 1 mRNA expression in peritoneal mononuclear cells (PMNCs) from peritoneal dialysate before, at the onset of and once a week during peritonitis and after peritonitis in patients with high peritonitis occurrence (HPO) and patients with low peritonitis occurrence (LPO). Fifteen patients with a LPO rate and 5 patients with a HPO rate were followed up longitudinally. Meanwhile, TGF beta 1 levels and TGF beta 1 mRNA expression were augmented in peritoneal dialytic fluid before, during, and after the episodes of peritonitis. Peritoneal permeability was evaluated by the peritoneal equilibration test (PET). The results revealed that in the LPO group, TGF beta 1 and TGF beta 1 mRNA were detectable at early stages of peritonitis, but the levels decreased rapidly and were undetectable 2 weeks after peritonitis. On the other hand, in the HPO group, TGF beta 1 and TGF beta 1 mRNA persisted for a long time. We could detect TGF beta 1 and TGF beta 1 mRNA in dialytic fluid and PMNCs even 2, 3, and 4 weeks after episodes of peritonitis. When compared with that of the first or second episode of peritonitis, peritoneal function evaluated with the PET was found to obviously deteriorate at the third episode of peritonitis. These findings were confirmed by an in situ hybridization technique to evaluate the relationship between TGF beta 1 mRNA expression and PF from biopsied peritoneal specimens. These findings suggest that the high TGF beta 1 levels in the dialysate are related to an increased expression of TGF beta 1 in the peritoneum. Persistent TGF beta 1 expression in the peritoneum may serve as a useful parameter in predicting PF in CAPD patients with frequent peritonitis occurrence.

Fludarabine-mediated repair inhibition of cisplatin-induced DNA lesions in human chronic myelogenous leukemia-blast crisis K562 cells: induction of synergistic cytotoxicity independent of reversal of apoptosis resistance

We demonstrated previously that the nucleoside of fludarabine (F-ara-A), a clinically effective agent against chronic lymphocytic leukemia and low-grade lymphoma, produces synergistic cytotoxicity against cisplatin-resistant CP2.0 human colon tumor cells when administered in combination with cisplatin. The purpose of this study was 2-fold: (i) to determine whether the synergy occurs in K562 human chronic myelogenous leukemia cells, which, unlike CP2.0 cells, are relatively resistant to drug-induced apoptosis because they express P210(bcr-abl) and (ii) to study the underlying mechanism for the synergy if the enhancement of cytotoxicity occurs in K562 cells. When K562 cells were treated with fludarabine nucleoside and cisplatin as single agents for 4 hr, IC50 values for fludarabine and cisplatin were 3.33 and 2.28 microM, respectively, as measured by a clonogenic survival assay. The simultaneous treatment of K562 cells with the two agents resulted in synergistic cell killing as determined by median-effect analysis. Such synergistic cell killing by combined cisplatin and fludarabine could not be detected in repair-deficient human xeroderma pigmentosum cell lines. Within the range of cytotoxic concentrations, fludarabine (2.5-15 microM) and cisplatin (3-30 microM) as single agents produced no detectable internucleosomal DNA fragmentation as revealed by gel electrophoresis, nor did the combination of the two drugs induce apoptotic DNA degradation. The effects of fludarabine on the repair of cisplatin-induced DNA adducts and interstrand cross-links in K562 cells were analyzed to determine their correlation with the cytotoxic synergy. The interstrand cross-links were measured by the ethidium bromide binding fluorescence assay and quantitative Southern blotting technique. Repair of the intrastrand adducts was detected with whole-cell extracts using a cisplatin-damaged plasmid as the substrate for the in vitro repair assay. Fludarabine at clinically achievable concentrations (1.5-4.5 microM fludarabine nucleoside; 20-100 microM fludarabine triphosphate) inhibited the repair of the DNA lesions induced by cisplatin in a dose-dependent fashion in K562 cells but not in xeroderma pigmentosum cells. Cotreatment with fludarabine preferentially increased the number of interstrand cross-links induced by cisplatin in actively transcribed genes in K562 cells. These data demonstrate the DNA-repair-inhibitory effect of fludarabine and suggest that this effect may contribute to the synergistic cytotoxicity of the fludarabine/cisplatin combination that resulted in decreased clonogenic survival of apoptosis-resistant K562 cells.

Cyclosporin pharmacokinetics following administration of capsules and Neoral in paediatric patients with lupus nephritis

AIMS

Neoral is a new microemulsion form of cyclosporin. Pharmacokinetic reports in children are scarce. Therefore, we performed a pharmacokinetic study between Cyclosporin A (CsA) capsules and Neoral in paediatric patients with lupus nephritis.

METHODS

A single 5 mg kg(-1) dose orally of either CsA capsules or Neoral was given to 10 paediatric patients (serum creatinine < 1.5 mg dl(-1)). CsA whole blood levels were measured for 24 h post-dose by h.p.l.c.

RESULTS

Neoral had a higher C(max) and AUC(C(max): 943 +/- 176 ng ml(-1); AUC: 4612 +/- 785 ng ml(-1) h) than those of the CsA capsules (C(max): 697 +/- 187 ng ml(-1); AUC: 3483 +/- 873 ng ml(-1) h; P < 0.05). There was no difference in t(max) and t(1/2,z) between the two groups.

CONCLUSIONS

CsA Neoral had improved absorption and bioavailability, which is similar to what is reported in adults. However, interpatient variability still existed. Careful drug monitoring and dose adjustment should be performed during treatment to avoid nephrotoxicity, especially in lupus nephritis.

Function of intromissions on intromission-return latency of female rats during paced sexual behavior

The objectives of this study were to examine how multiple intromissions affect the temporal pattern of the female rat's copulatory behavior; in particular, her latency to return to the male following intromission (intromission-return latency, IRL) and if different hormone replacement regimens affect the temporal aspects of female copulatory behavior. Repeated intromissions alone, without ejaculation, often resulted in prolonged IRLs equal to the postej aculatory refractory period (PER). The first prolonged IRL occurred most frequently between the 24th and 44th intromission. The similar pattern of IRLs around the PER and the prolonged IRLs may indicate that the mechanisms mediating the occurrence of the prolonged IRL are similar to those for the PER. One possible function of the prolonged IRLs may be to facilitate the male's ejaculation after the female has received enough vaginocervical stimulation for the induction of the progestational state of pregnancy. Finally, females receiving a single dose of 50 microg estradiol benzoate (EB) followed by an injection of 0.5 mg progesterone (P) 48 h later showed a significantly longer PER than those receiving 3 daily injections of 0.5 microg EB followed by an injection of 0.5 mg P 24 h after the last EB injection.

Fludarabine triphosphate inhibits nucleotide excision repair of cisplatin-induced DNA adducts in vitro

Fludarabine (9-beta-arabinofuranosyl-2-fluoroadenine-5'-monophosphate) is clinically active against chronic lymphocytic leukemia and low-grade lymphomas. We reported previously that fludarabine nucleoside synergistically enhanced cisplatin (CDDP)-induced cytotoxicity in vitro, and that the synergism was concomitant with inhibition of removal of cellular CDDP-induced DNA interstrand cross-links, which are presumably repaired by homologous recombinational repair. To extend our work, we investigated whether fludarabine inhibits nucleotide excision repair (NER) of CDDP-induced DNA intrastrand adducts. The effect of fludarabine on NER was determined using a cell-free system in which a plasmid containing the DNA adducts served as the substrate for repair enzymes in whole-cell extracts from repair-competent cells. To prevent the cell-bound high mobility group box-containing proteins from interfering with repair, cell extracts were depleted with high mobility group box proteins by immunoprecipitation prior to the assay. Repair synthesis, measured by the incorporation of [(32)P]dATP or [(32)P]dCTP, was inhibited by 50% at 26 or 43 microM fludarabine triphosphate, respectively; the effect was dose dependent and may have resulted from the termination of repair-patch elongation. These results were consistent with those from pulse-chase experiments demonstrating the conversion of nicked circular plasmid to the closed circular form by cell extracts filling the repair gaps. When proliferating cell nuclear antigen-depleted cell extracts were used and aphidicolin was added in the repair assay to arrest NER at the incision/excision stage, 100 microM fludarabine triphosphate inhibited about 55% of the conversion of nicked plasmids from the closed circular damaged plasmid substrate; the inhibition was dose dependent. We conclude that fludarabine triphosphate inhibited NER at the steps of incision and repair synthesis. These results suggest that fludarabine may serve as a potential repair modulator to improve the antitumor efficacies of combination regimens containing agents that induce NER.

A study of the relationship between IgG subclass/IgM and idiopathic nephrotic syndrome

In an attempt to elucidate the relationship between serum IgG subclass/IgM ratio and prognosis in different types of idiopathic nephrotic syndrome (INS), 46 cases of treatment responders and 23 cases of either frequent relapse or non-responders were studied. All patients had received renal biopsy. Serum IgG subclass/IgM ratios were compared between the acute nephrotic phase and remission. The association between therapeutic effect and the parameters of INS were also investigated. There were 24 cases of minimal change nephrotic syndrome (MCNS), 32 cases of IgM nephropathy (IgMN) and 13 cases of focal segmental glomerular sclerosis (FSGS). All cases of MCNS were steroid-responders. Seventeen cases of IgMN experienced frequent relapses. The other 15 cases were responsive to the treatment. 6 cases of FSGS had poor response to any therapy; 7 cases were responsive to either triple therapy or cyclosporine A plus prednisolone. Both IgGI/IgM and IgG2/IgM were correlated with serum albumin and cholesterol levels at the acute nephrotic phase (p < 0.05). Longitudinal change of the immunologic parameters in patients with INS revealed significantly elevated serum IgM level decreased serum IgG level, IgG/IgM, IgG1/IgM, IgG2/IgM, IgG3/IgM, IgG4/IgM and IgG/IgE ratio during acute nephrotic phase. Correlation between therapy responses showed that, for serum IgG1/IgM ratio > 3.0, most of the cases were treatment-responders. For IgG1/IgM ratio > 1.0, all the cases were frequent relapsers or non-responders. These results suggest the immunologic changes in patients of INS may be caused by immune regulatory abnormality. Serum IgG1/IgM ratio may serve as one of the therapeutic and prognostic guides, especially if the patient refuses renal biopsy.

Relation of intromissions to the female's postejaculatory refractory period in rats

The objectives of this study were to investigate the temporal aspects of female sexual behavior during single and multiple ejaculatory tests. Females were tested in a two-compartment chamber where they could escape from the male following sexual contacts. In Experiment 1, correlation analysis showed that the number of intromissions received by the female over 3 ejaculatory series was positively correlated with the female's postejaculatory refractory period (PER). In Experiment 2, females receiving 2-4 intromissions before ejaculation had a PER that did not differ from those receiving 5-15 (average 10) intromissions preceding ejaculation. However, if the male ejaculated on the first or second intromission, the female's PER was significantly shorter than the other groups and did not differ from her return latency after an intromission without ejaculation. Females receiving 24-31 intromissions preceding ejaculation exhibited the longest PER. Analysis revealed that the number of intromissions received by females before ejaculation was positively correlated with the female's PER. We concluded that the male's ejaculatory reflex, seminal emission, and postejaculatory behavior alone without at least 2 preceding intromissions were not sufficient to induce a female's PER comparable to that seen after an ejaculation during normal copulation. In addition, the number of intromissions received by the female preceding ejaculation was positively correlated with the female's PER if the range of intromission frequency was large enough.

Preincubation of Dacron grafts with recombinant tissue factor pathway inhibitor decreases their thrombogenicity in vivo

BACKGROUND

We have previously shown that preincubation of whole blood clots with recombinants tissue factor pathway inhibitor (rTFPI) attenuates clot-associated procoagulant activity assessed ex vivo. This study was undertaken to determine whether a single local application of rTFPI induces similar attenuation of the procoagulant activity on preclotted Dacron grafts implanted in an artery in vivo.

METHODS

Dacron grafts (4 mm x 4 cm long) were preclotted in porcine blood and incubated with either rTFPI (5 mg/ml) or arginine-phosphate buffer for 15 minutes. Grafts were implanted end-to-end in the femoral arteries of 10 pigs, with one rTFPI-treated and one buffer-treated graft implanted in each animal. Animals did not undergo anticoagulation either before or after graft implantation. Radiolabeled porcine fibrinogen was injected intravenously, and the grafts underwent perfusion for 1 hour. A subgroup of animals (n = 7) also had infusion of radiolabeled autologous platelets at the time of administration of radiolabeled fibrinogen.

RESULTS

Fibrin(ogen) deposition was decreased in rTFPI-treated grafts by 36% +/- 7% (mean +/- SEM) compared with buffer-treated grafts (p = 0.001). Platelet deposition was also reduced in the rTFPI-treated grafts by 31% +/- 15%, although the reduction did not reach statistical significance (p = 0.10). The extent of rTFPI-mediated attenuation of fibrin(ogen) versus platelet deposition varied independently among animals.

CONCLUSIONS

Clot-directed anticoagulant effects of rTFPI appear to be useful for substantially decreasing the thrombogenicity of Dacron grafts immediately after their implantation. Chronic studies to determine whether the decreases in thrombogenicity result in improved long-term graft patency appear warranted.

Early detection of neonatal adrenal hemorrhage by ultrasonography

To investigate clinical features and course of neonatal adrenal hemorrhage (NAH) from July 1992 to August 1993, fifteen babies suffering from NAH born at Veterans General Hospital-Taipei were included. Portable ultrasound scanner was used for initial screening. The frequency of NAH was approximately 0.35% which is lower than other reports. The distribution of their birth weight was 3 cases lower than 3000 gm, 3 cases over 4000 gm and 9 cases within 3000 to 4000 gm. Only one was premature and another one post-term. Four of them had a history of either prenatal or perinatal asphyxia. Only one patient had a palpable abdominal mass. On the sonographic findings, eleven had bleeding in the right-side, two in the left-side and two in both sides. Only one had adrenal calcification. During their early life, no patient developed adrenal cortical insufficiency or secondary profuse bleeding. Two patients had pathologic jaundice. Two patients had severe anemia. After conservative treatment, none of them developed any severe complication. In conclusion, with the aid of renal sonoscreening in the newborn, we can discover NAH early and give adequate treatment at once. Severe complications also can be prevented.

Evaluation of CI-973, a platinum analogue, in refractory or relapsed acute leukemia

The purpose of the study was to define the maximally tolerated dose (MTD), major toxicities, and possible antitumor activity of CI-973 a new platinum analogue, in patients with refractory or relapsed acute leukemia. CI-973 was given as a 5-day continuous infusion every 3 to 4 weeks to patients with refractory or relapsed acute leukemia, at doses ranging from 150 mg/m2 to 1350 mg/m2 per course. Thirty-six patients were treated including 18 patients with acute myelogenous leukemia (AML), four with acute lymphocytic leukemia (ALL) and 14 with chronic myelogenous leukemia in blastic phase (CML-BP). Severe gastrointestinal and renal side-effects were the dose-limiting toxicities occurring in four of five patients treated with CI-973 1200 to 1350 mg/m2 per course. At the MTD of 1000 mg/m2 per course, three of 13 patients treated (23%) had moderate to severe nausea and vomiting, three (23%) had moderate diarrhea and one had moderate mucositis. Among 21 patients treated at > or = 1000 mg/m2 (15 AML, 6 CML-BP) no objective complete or partial responses were observed. Twelve of 18 patients (66%) with evaluable marrows on day 14 showed significant suppression of marrow blasts percentage and marrow leukemic infiltrate percentage. Tests for measurement of DNA adduct formation in leukemic cells in vivo after CI-973 therapy, and in vitro following exposure of leukemic cells to CI-973 were developed. This study defined the MTD of CI-973 to be 1000 mg/m2 by continuous infusion over 5 days every 3 to 4 weeks in patients with refractory or relapsed acute leukemia. Gastrointestinal and renal side-effects were dose-limiting. No objective responses were noted in this heavily resistant population. Correlations between CI-973-induced DNA adduct formation and individual patient response to CI-973 will help to define its role in leukemia subsets.

Contribution of de novo fatty acid synthesis to very low density lipoprotein triacylglycerols: evidence from mass isotopomer distribution analysis of fatty acids synthesized from [2H6]ethanol

A detailed comparison of the structures of plasma very low density lipoprotein (VLDL) and liver triacylglycerols (TG) (Yang et al. 1995. J. Lipid Res. 36: 125-136) has demonstrated that a minimum of 60% of the secreted TG could have been derived from partial lipolysis and reesterification of stored TG and a maximum of 40% could have been derived from direct secretion of newly made TG. To investigate the processes involved in the transfer of TG to VLDL in vivo, we have determined the distribution of deuterium among the molecular species of the liver-TG and VLDL-TG during the infusion of perdeuterated ethanol along with fructose or glucose and during the provision of either glucose or fructose in the drinking water for 2 weeks. The deuterium labeling (percent excess and percent replacement) of the total fatty acids was determined by GC/MS of the methyl esters while the labeling of the glycerol and the glycerol plus fatty acids of the enantiomeric diacylglycerol moieties of TG was determined by LC/MS with on-line mass spectrometry. Supplementation of the diet for 2 weeks with either glucose and fructose stimulated the synthesis of TG containing new fatty acids and glycerol. The proportion of the newly made to preexisting TG differed in VLDL from that in the liver. The 2H % replacement in glycerol and in total fatty acids was greater in VLDL-TG than in the liver-TG. On the basis of the mass isotopomer distribution analysis it was estimated that a maximum of 30% of the VLDL-TG could have been derived directly from TG that was made de novo and did not equilibrate with the liver-TG stores. The transfer of the stored TG to VLDL was best accounted for by a degradation to 2-monoacylglycerols and resynthesis via the 2-monoacylglycerol pathway with addition of an excess of newly synthesized fatty acids to the resynthesized TG.

Peritonitis in children being treated with continuous ambulatory peritoneal dialysis. CAPD Team

An eight-year retrospective study was performed to determine the incidence of peritonitis in a pediatric continuous ambulatory peritoneal dialysis (CAPD) population of 24 children, half of whom were boys and half, girls. All suffered from end stage renal disease (ESRD). When these children, aged 2 through 17 years (mean: 10.7 +/- 3.8), were examined, the incidence of peritonitis was one episode every 15.2 patient-months. Microbiologic evaluation showed that 76.4% of the 34 episodes were culture positive, with Staphylococci species (coagulase negative staphylococci 32.4%, Staphylococcus aureus 14.7%) causing most cases especially early in dialysis. Half the patients presented with a triad of symptoms (fever, abdominal pain and cloudy dialysate), with cloudy dialysate was the major presentation (88%). Peritonitis was treated with intraperitoneal administration of cefacin and/or netromycin when suspected, and 52.9% of the episodes needed hospitalization. Except for two patients who died of complications (sepsis, acute pancreatitis), all episodes of peritonitis were cured; in four episodes it was necessary to remove a catheter, and two of those cases came from fungal peritonitis. Peritonitis rates differed among disconnect systems. The manual spike had peritonitis rate of one episode per 4.6 patient-months which was higher than the O-set (one episode/22.2 patient-months), UV-XD and Y-set disconnect systems. Therefore, the major causes of peritonitis arose from contamination provoked by the technical aspect of the procedure. Nutrition status was stable in these patients. Serum albumin and total protein were adequate in all patients without relation to episode of peritonitis.(ABSTRACT TRUNCATED AT 250 WORDS)