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)

Hypoglycemia following ethanol ingestion in children: report of a case

Ethanol is present in a large number of pharmaceuticals, cosmetics, detergents and beverages. Without adequate safety measures, the accidental ingestion of such products by children is possible. Ethanol ingestion by children is known to cause various metabolic and neurologic disorders, including hypoglycemia, metabolic acidosis, seizures or coma. In Taiwan, little information has been published regarding the effects of ethanol ingestion by children. This is a report of a 5-year-old boy who became hypoglycemic after ingestion of rice wine. Admitted in a coma, the boy regained consciousness within 30 min after slow administration of 5% dextrose. His initial plasma glucose level was extremely low and hypokalemia was also found. Blood ethanol was 159 mg/dL, 3 h after the alcohol ingestion. He was discharged in good health the following day. Ethanol-induced hypoglycemia may be easily overlooked as symptoms of adrenaline excess are frequently absent. Prompt recognition and treatment with intravenous glucose are essential and may be life-saving. Pediatricians need to be aware of the devastating impact of ethanol. Preventive measures, such as child-proof packaging and parent education, are required if ethanol intoxication in children is to be avoided.

Arabinosyl-2-fluoroadenine augments cisplatin cytotoxicity and inhibits cisplatin-DNA cross-link repair

Cytotoxicity was increased significantly when arabinosyl-2-fluoroadenine (F-ara-A) was administered in simultaneous combination with cisplatin (CDDP) to human colon tumor cell lines relatively sensitive (LoVo) or resistant (CP2.0) to CDDP. Because the mechanism of action of F-ara-A indicates that it may be an effective inhibitor of DNA repair, we hypothesized that F-ara-A induces cytotoxic augmentation by suppressing cellular repair in CDDP-damaged DNA lesions. To test this, we compared the repair of CDDP-induced DNA interstrand cross-links in the total genome and in ERCC1 gene-specific sequences of LoVo and CP2.0 cells for treatments with CDDP and CDDP plus F-ara-A. We determined the DNA repair by measuring the rate of removal of the cross-links, using two methods, i.e., an ethidium bromide fluorescence binding assay, which detects the DNA lesion in the total genome, and a method combining denaturation/renaturation neutral agarose gel electrophoresis and Southern hybridization to detect gene-specific lesions. When F-ara-A (15 microM) was coadministered with CDDP (15 micrograms/ml for LoVo cells and 30 micrograms/ml for CP2.0 cells) for 4 hr, the initial cross-link index for the total genome was increased 67% (4.5 versus 2.7 with CDDP alone) in LoVo cells and 93% (2.9 versus 1.5 with CDDP alone) in resistant CP2.0 cells. At 10 hr after the treatment, only 5% of the cross-links had been removed in combination-treated LoVo cells, compared with 40% in CDDP-treated LoVo cells; in CP2.0 cells, F-ara-A inhibited the removal of cross-links from 95% to 45%. Similar results were obtained for ERCC1 gene-specific DNA sequences. These data suggest that F-ara-A enhances the accumulation of CDDP-induced cross-links in LoVo and CP2.0 cells by suppressing the repair of such lesions, thereby enhancing the cytotoxicity of CDDP in combination treatment.

Biosynthesis of chylomicron triacylglycerols by rats fed glyceryl or alkyl esters of menhaden oil fatty acids

We have previously shown great similarity in the distribution of fatty acids in the sn-1 and sn-3 positions of the chylomicron triacylglycerols (TG) from rats fed menhaden oil or its ethyl esters, and have proposed that the acylglycerol products of the phosphatidic acid (PA) pathway (ester feeding) are hydrolyzed to 2-monoacylglycerols (2-MG) prior to reconversion to TG via the 2-MG pathway (oil feeding) and secretion as chylomicrons. As the composition of the sn-2-position would also be retained if the TG were hydrolyzed only to the X-1,2-diacylglycerol (DG) stage before resynthesis, we have now retested the hypothesis by determining the molecular association and reverse isomer content of the sn-1,2- and sn-2,3-DG derived from the chylomicron TG and the PA resulting from the two feedings. The new data demonstrate a better than 90% homology among the molecular species of the PA from the oil and ester feeding, along with the characteristic association of the saturated acids with sn-1- and the unsaturated acids with sn-2-position. Due to increased proportion of unsaturated acids in the sn-1-position of the TG, there was only a 15-20% homology between the PA and the sn-1,2-DG moieties of the chylomicron TG from the oil and ester feeding. A lack of homology was also observed between the PA and free sn-1,2-DG, as well as between the free sn-1,2-DG and the sn-1,2-DG moieties of the chylomicron TG. On the basis of molecular association and the sn-1-/sn-3- reverse isomer content of the chylomicron TG a better than 90% homology was recognized between the chylomicron TG resulting from the oil and ester feeding. It is therefore concluded that hydrolysis to 2-MG followed by reesterification via the 2-MG pathway constitutes the most plausible mechanism for the transfer to chylomicrons of the TG arising from alkyl ester feeding.

Origin of triacylglycerol moiety of plasma very low density lipoproteins in the rat: structural studies

We have compared the molecular species composition of the glycerolipids of rat liver and rat plasma very low density lipoproteins (VLDL). There were differences in the stereospecific distribution of the fatty acids in the triacylglycerols (TG) of the liver and of VLDL. While chiral and reversed phase chromatography with mass spectrometry (LC/MS) revealed great similarities in positional distribution and molecular association of the fatty acids between the sn-1,2-diacylglycerol (DG) moieties of the VLDL and liver TG, the corresponding sn-2,3-DG were distinctly different. The free hepatic sn-1,2-DG and the sn-1,2-DG moiety contained within hepatic phosphatidic acid showed a maximum 60% homology to the sn-1,2-DG contained within the TG of the liver and of VLDL. By contrast, the smaller pool of hepatic free sn-2,3-DG was nearly identical to the sn-2,3-DG moiety contained in the TG of the liver. These differences between hepatic and VLDL TG indicate that direct transfer of hepatic triacylglycerols is not a major mechanism of VLDL TG formation. On the other hand, the results suggest that stored hepatic TG are largely hydrolyzed to sn-1,2-DG and then reesterified to TG before being secreted as VLDL TG. Although an involvement of 2-monoacylglycerol pathway could not be excluded, it probably plays a minor role in VLDL TG formation. Our data suggest that a minimum of 60% of the VLDL TG could have been derived via hydrolysis to DG and reesterification, and a maximum of 40% could have originated via the conventional phosphatidic acid pathway.

[In situ hybridization and immunohistochemical detection of bone morphogenetic protein genes in ameloblastomas]

Bone morphogenetic protein (BMP) is related to the formation of bone and dentin. Immunohistochemical study showed that ameloblasts, odontoblasts and dental papilla cells contained much BMP. It is indicated BMP might be associated with the epothelial-mesenchymal interaction of tooth germs. In this study, the expression and distribution of BMP in 40 patients with ameloblastomas were observed by using in situ hybridization and immunohistochemistry. The results showed that all three BMP genes were overexpressed in the epithelial component of ameloblastomas, however, no positive reaction was found in immunohistochemistry. It is indicated that overexpression of BMP genes might be related to the development of ameloblastomas.

Lupus nephritis in children--a review of 167 patients

BACKGROUND

Relatively few studies have been made of children with lupus nephritis. The prognosis of children with lupus nephritis is ominous for those with diffuse proliferative glomerulonephritis and active interstitial inflammation. Up to now few studies have been made on this subject.

OBJECTIVES

To evaluate the clinical course, histopathology, and prognosis of lupus nephritis in children, to identify the risk factors for renal failure and mortality, and to share our experience in treating lupus nephritis in children.

METHODS

Retrospectively, 167 children under 18 years of age with lupus nephritis at Veterans General Hospital-Taipei, Taiwan from 1979 to 1991 were studied. All patients received renal biopsy and follow-up biopsies were performed in 36 children. The clinical and serologic parameters at the time of renal biopsy were recorded.

RESULTS

There were 55 (33%) patients with class II, 30 (18%) with class III, 69 (41.3%) with class IV, and 13 (7.8%) with class V nephritis based on initial biopsy. The mean follow-up time was 59 months. Follow-up biopsies were histologically stationary in 29 patients, progressive in five, and regressive in two. The results revealed that those with persistent hypertension, anemia, increased serum creatinine concentration, and decreased creatinine clearance rate at initial biopsy were more prone to develop renal failure. Low titer of CH50 hemolytic assay appeared to be a poor prognostic indicator. The overall renal and patient 5-year survival rates were 93.1% (135/145) and 91.08% (143/157), respectively. They were 87.7% (50/57) and 82% (55/67), respectively, of patients with class IV proliferative glomerulonephritis.

CONCLUSIONS

The prognosis of children with class IV nephritis in this study was better than that reported previously. All children surviving without renal failure were maintaining their normal lives with little organ dysfunction. The improved results may be due to earlier renal biopsy for precise histopathologic definition, better supportive care, and selective use of aggressive therapy, including methylprednisolone pulse therapy, intravenous cyclophosphamide, intravenous prostaglandin E1 therapy, high-dose intravenous gammaglobulin therapy, and cyclosporin A for those with high risk factors.

Comparison of the effect of hyperinsulinemia on acyl-CoA:cholesterol acyltransferase activity in the liver and intestine of the rat

Recent studies have suggested that cholesteryl ester synthesis plays a critical role in the assembly of VLDL apo B and triacylglycerol in the liver. Chronic hyperinsulinemia is associated with increased TG production and since cholesteryl ester synthesis depends on acyl CoA:cholesterol acyltransferase (ACAT), we investigated the possibility that chronic hyperinsulinemia might increase ACAT activity. We also measured ACAT activity in the intestinal mucosa, where it has been suggested to play a role in induction of diabetes-associated hypercholesterolemia. Chronically hyperinsulinemic rats were produced by injecting insulin (2 weeks, 6U/day). To prevent profound hypoglycemia, these rats were given 10% sucrose in place of drinking water. Acute hyperinsulinemia was produced by injecting a single dose of 0.5 U insulin ip. Chronic hyperinsulinemia led to a significant increase in free cholesterol, cholesteryl esters, triacylglycerols and phospholipids in the whole liver (27%, P < 0.05; 60%, P < 0.05; 70%, P < 0.01; 37%, P < 0.01, respectively) and an increase in hepatic microsomal triacylglycerol (P < 0.05). In contrast, the microsomal lipids of the intestinal mucosa decreased significantly. In chronically hyperinsulinemic rats there was no change in hepatic ACAT, while ACAT in the intestine actually decreased (26%-50%, P < 0.01).

CONCLUSIONS

since the effect of chronic hyperinsulinemia on hepatic ACAT did not parallel that seen previously on VLDL secretion, the effect of chronic hyperinsulinemia on VLDL production cannot be explained by its effect on hepatic ACAT. However, chronic hyperinsulinemia was associated with reduced ACAT activity in the intestine and this might result in decreased lipoprotein production in the hyperinsulinemic intestine.

Cellular accumulation and DNA damage induced by liposomal cis-bis-neodecanoato-trans-R,R-1,2-diaminocyclohexaneplatinum+ ++(II) in LoVo and LoVo/PDD cells

Liposomal cis-bis-neodecanato-trans-R,R-1,2-diaminocyclohexaneplatinum (11) (L-NDDP) is a liposome-entrapped platinum complex that has shown partial lack of cross-resistance with cisplatin in human colon carcinoma LoVo cells. We studied the drug accumulation and DNA damage induced by L-NDDP and cisplatin in LoVo and LoVo/PDD cells. Our results indicate that the accumulation of L-NDDP in LoVo cells is several-fold higher than that of cisplatin; that the accumulation of L-NDDP is similar in both cell lines, whereas that of cisplatin is reduced by 2- to 3-fold in LoVo/PDD cells; and that the transmembrane transport of cisplatin is highly dependent on temperature while that of L-NDDP is not. We also found that the cytotoxicity of both agents correlates with the extent of DNA-protein cross-link formation, and that DNA interstrand cross-linking does not appear to play a role in the cytotoxicity of L-NDDP, whereas it correlates with cisplatin cytotoxicity.

New initiatives with fludarabine monophosphate in hematologic malignancies

Fludarabine monophosphate (fludarabine) was initially discovered to have significant activity in indolent lymphoma and chronic lymphocytic leukemia (CLL). The major clinical experience with fludarabine is in previously treated patients with CLL. In such patients the complete and partial response rate (CR + PR) is over 50%. These results were obtained with 5-day schedules of fludarabine 25 to 30 mg/m2/d. Subsequent schedules have explored once-a-week fludarabine and a 3-day schedule every 4 weeks. These strategies, in particular the once-a-week schedule, have obtained inferior results. The addition of prednisone has not been associated with an improvement in response rate or survival. The application of fludarabine to previously untreated patients demonstrated a CR + PR rate of 75% to 80%. The addition of prednisone did not improve the response rate or survival in this group of patients. A significant concern in patients with CLL treated with fludarabine is a decrease in the CD4 and CD8 counts. Despite median posttreatment counts of approximately 200 CD4 lymphocytes/microL, the incidence of infections in patients in remission off therapy is low. Major clinical activity has been demonstrated with fludarabine in Waldenstrom's macroglobulinemia, in which more than one third of refractory patients achieve a CR or PR. Responding patients with anemia or thrombocytopenia have a marked improvement in blood counts. The duration of response has been long (> 30 months) in most responders. The early activity of fludarabine as a single agent in phase I/II studies in indolent lymphoma subsequently has been confirmed by a number of investigators. Fifty percent to 60% of patients with follicular lymphomas respond to fludarabine as a single agent. A number of these responses are complete despite the patients having received extensive prior treatment. A number of combination programs are being developed in CLL and indolent lymphoma. The combination of fludarabine with doxorubicin and prednisone has been developed and is being studied in phase I/II clinical trials. In addition, combinations of fludarabine and cytarabine with or without cisplatin based on elegant preclinical pharmacokinetic rationales have been applied to CLL with impressive cytoreductive activity but significant myelosuppression. A new combination of fludarabine, mitoxantrone, and dexamethasone has been developed for use in lymphoma. Phase I studies demonstrated a high response rate, especially in follicular lymphomas, with a number of patients achieving complete remission. Subsequent phase II studies demonstrate a response rate of 89% in patients with indolent lymphoma.(ABSTRACT TRUNCATED AT 400 WORDS)

Fludarabine: pharmacokinetics, mechanisms of action, and rationales for combination therapies

Knowledge of the pharmacokinetics of a drug is essential to the optimal design of the dose and schedule of chemotherapy protocols. As an extension, an understanding of the mechanism of drug action is necessary to construct the optimal strategy for combination chemotherapy. Nucleoside antimetabolites such as fludarabine are pro-drugs that must enter cells and be phosphorylated to the nucleoside triphosphate before they can elicit biologic activity. Thus, knowledge of the pharmacokinetics of the triphosphate in target cells and an understanding of the mechanisms by which this active form of the drug act are indispensable to the rational design of treatment protocols. This article reviews the essential elements of the pharmacokinetics and mechanisms of action of fludarabine to provide a rationale for combinations of fludarabine with other chemotherapeutic agents and anti-cancer modalities.

In vitro cytotoxicity, cellular pharmacology, and DNA lesions induced by annamycin, an anthracycline derivative with high affinity for lipid membranes

Annamycin (AN) is an anthracycline antibiotic with high affinity for lipid membranes which is being developed for clinical studies formulated in liposomes. We studied the in vitro cytotoxicity, cellular pharmacology, and DNA damage induced by AN in P388 cells sensitive and resistant to doxorubicin (DOX). AN was as cytotoxic as DOX against P388-sensitive cells and about 50 times more cytotoxic than DOX against P388-resistant cells (resistance index 5 for AN versus 250 for DOX). Cellular uptake of AN by sensitive cells was 2-3-fold higher than that of DOX. In resistant cells, cellular uptake of AN and DOX was approximately 65% and 30%, respectively, of the cellular uptake in sensitive cells. As a result, cellular uptake of AN by resistant cells was higher than uptake of DOX by sensitive cells. DOX was fully retained in sensitive cells while it was effluxed rapidly from resistant cells. In contrast, efflux of AN was similar in sensitive and resistant cells, thus suggesting that it is not mediated by P-glycoprotein. AN was more effective than DOX in inducing single DNA breaks, double DNA breaks, and DNA-protein cross-links, both in sensitive and resistant cells, although DNA damage was lower in resistant cells than in sensitive cells. DNA lesions induced by AN in resistant cells were similar to or greater than those induced by DOX in sensitive cells. These studies indicate that the lack of cross-resistance between DOX and AN appears to be related, at least in part, to the relatively higher cellular uptake of AN compared with DOX and is associated with the ability of AN to induce significant DNA damage in resistant cells.

Distinct P-glycoprotein expression in two subclones simultaneously selected from a human colon carcinoma cell line by cis-diamminedichloroplatinum (II)

Two drug-resistant sublines, CP2.0 and RT, were simultaneously selected by cis-diamminedichloroplatinum (CDDP) from the human colon carcinoma cell line LoVo by the conventional method of continuous drug exposure. The 2 sublines differed in morphology, growth kinetics and pattern of gene expression. Genetic signature analysis indicated that the lines were independent subclones but that both arose from LoVo. These sublines were maintained in a growth medium containing 2.0 micrograms/ml CDDP. However, CP2.0 cells were 3 times more resistant to CDDP than were RT cells. Although both were cross-resistant to mustargen and 5-fluorouracil, only CP2.0 was resistant to Adriamycin and vincristine. Western-blot analysis, immunocytochemical staining and in vitro phosphorylation experiments indicated that the level of P-glycoprotein was significantly elevated in CP2.0 but not in RT. Despite the differences between these sublines, they possess similar CDDP-resistance mechanisms, including decreased intracellular CDDP accumulation, elevated levels of glutathione and metallothionein-like proteins, increased glutathione transferase-pi mRNA, and enhanced susceptibility to CDDP cytotoxicity after treatment with DL-buthionine-[S,R]-sulfoximine. Nevertheless, our results suggest that, in certain tumor types, P-glycoprotein-mediated multi-drug resistance and CDDP-resistance phenotypes can coexist in cells with primary resistance to CDDP.

Plasma levels of atrial natriuretic factor in normal children and patients treated by hemodialysis and continuous ambulatory peritoneal dialysis

In an attempt to establish the reference data of plasma levels of atrial natriuretic factor (ANF) in different age groups and to evaluate plasma ANF changes before and after hemodialysis (HD) and during continuous ambulatory peritoneal dialysis (CAPD), fifty normal healthy children and 20 children with end-stage renal disease (ESRD) were included. Ten ESRD children received HD and 15 received CAPD therapy. Five cases received HD in the earlier period and then CAPD. The results showed that in normal children, at the age of under one month, there were higher plasma ANF levels. As age increased, plasma ANF levels progressively decreased. During the ESRD before dialysis, there was a significantly increased plasma ANF level (434.1 +/- 80.1 vs 17.5 +/- 2.3 pg/ml, P < 0.0001). Both HD and CAPD reduced the plasma ANF of patients to a lower degree, but the result was still higher than that in normal controls. There were significantly decreased plasma ANF level in the patients with CAPD therapy than those with HD (71.8 +/- 13.7 vs 270.3 +/- 51.9 pg/ml, P < 0.0001). The change of ANF levels was positively correlated with the body weight change and creatinine change after HD.

Surface components of chylomicrons from rats fed glyceryl or alkyl esters of fatty acids: minor components

The lipid class, fatty acid and molecular species composition of the minor polar surface components of rat lymph chylomicrons were determined during absorption of menhaden oil and corn oil or of the corresponding fatty acid ethyl esters. In addition to the previously reported minor polar lipids (sphingomyelin, phosphatidylserine, phosphatidylinositol, phosphatidic acid and lysophosphatidylcholine), we identified phosphatidylglycerol, dimethylphosphatidylethanolamine, ceramide and cholesteryl sulfate in the chylomicrons from both oil and ester feeding. The dietary fatty acids were found to be incorporated to a variable extent into the different phospholipid classes, the proportions of which remained the same during both types of feeding. No evidence was obtained for the presence of the minor glycerophospholipids characteristic of the lysosomal membranes (e.g., bis-phosphatidic, lysobisphosphatidic and semilysobis-phosphatidic acids), although special efforts were made to identify them. These results indicate that the chylomicrons arising from the monoacylglycerol and phosphatidic acid pathways of triacylglycerol biosynthesis become enveloped in closely similar monolayers of phospholipids. Hence, all triacylglycerols may be secreted from the villus cells via a common mechanism as suggested by the previously demonstrated convergence (at the 2-monoacylglycerol stage) of the monoacylglycerol and the phosphatidic acid pathways of mucosal triacylglycerol formation [Yang, Y.L., and Kuksis, A. (1991) J. Lipid Res. 32, 1173-1186].

Further characterization of two distinct adriamycin-resistant sublines from LoVo human colon carcinoma cells

We previously reported that two multidrug resistant sublines, AdR1.2 and SRA1.2, derived from LoVo human colon carcinoma cells, apparently expressed different resistance phenotypes including differential expression of p-glycoprotein (Pgp). Here, we further examined and compared other potential resistance mechanisms between AdR1.2 and SRA1.2 resistant cells. Our results showed that the Pgp-mediated AdR1.2 cells possessed an activated drug efflux pump and decreased nucleus binding of Adriamycin, while the non-Pgp-mediated SRA1.2 cells only held the second feature. Verapamil, however, partially reversed resistance in both sublines. Although glutathione-s-transferase was overexpressed in AdR1.2 but not in SRA1.2, both sublines had lower susceptibilities to drug-induced DNA strand breaks and greater capacities to repair such damage than did LoVo cells. These data suggest that, despite the differences in multidrug resistance phenotypes, the features of decreased susceptibility to DNA damage and enhanced DNA repair capacities may represent the common mechanisms responsible for drug resistance in both Pgp- and non-Pgp-mediated multidrug resistant cells.

Reattachment of surface array proteins to Campylobacter fetus cells

Campylobacter fetus strains may be of serotype A or B, a property associated with lipopolysaccharide (LPS) structure. Wild-type C. fetus strains contain surface array proteins (S-layer proteins) that may be extracted in water and that are critical for virulence. To explore the relationship of S-layer proteins to other surface components, we reattached S-layer proteins onto S- template cells generated by spontaneous mutation or by serial extractions of S+ cells with water. Reattachment occurred in the presence of divalent (Ba2+, Ca2+, Co2+, and Mg2+) but not monovalent (H+, NH4+, Na+, K+) or trivalent (Fe3+) cations. The 98-, 125-, 127-, and 149-kDa S-layer proteins isolated from strains containing type A LPS (type A S-layer protein) all reattached to S- template cells containing type A LPS (type A cells) but not to type B cells. The 98-kDa type B S-layer protein reattached to SAP- type B cells but not to type A cells. Recombinant 98-kDa type A S-layer protein and its truncated amino-terminal 65- and 50-kDa segments expressed in Escherichia coli retained the full and specific determinants for attachment. S-layer protein and purified homologous but not heterologous LPS in the presence of calcium produced insoluble complexes. By quantitative enzyme-linked immunosorbent assay, the S-layer protein copy number per C. fetus cell was determined to be approximately 10(5). In conclusion, C. fetus cells are encapsulated by a large number of S-layer protein molecules which may be specifically attached through the N-terminal half of the molecule to LPS in the presence of divalent cations.

Induction of NAD(P)H:quinone reductase in human peripheral blood lymphocytes

The induction of quinone reductase [QR; NAD(P)H:(quinone acceptor) oxidoreductase; EC 1.6.99.2] in cultured cells and animal tissues of rodents has provided useful information on mechanisms of protection against carcinogens. We have developed a simple and efficient microtiter plate assay for the direct measurement of QR basal activity and inducibility in human peripheral blood lymphocytes (unstimulated, mitogen-stimulated and Epstein-Barr virus-transformed) grown in suspension culture. In these cells, QR was induced by monofunctional (electrophilic) inducers (i.e. 1,2-dithiole-3-thione, dimethyl fumarate, methyl vinyl sulfone) but not by bifunctional inducers (i.e. 1,1'-azonaphthalene, beta-naphthoflavone, 2,3,7,8-tetrachlorodibenzo-p-dioxin). QR is a major enzyme of xenobiotic metabolism that carries out obligatory two-electron reductions and thereby protects cells against the toxicity of quinones. It is induced in many tissues coordinately with other enzymes that protect against electrophiles. Since lymphocytes can be sampled easily and repetitively in man, this system may provide a simple short-term marker for assessing the capacity of tissues to detoxify electrophiles, such as quinones, and for measuring the response to inducers.

Endotracheal administration of epinephrine during cardiopulmonary resuscitation

A hypoxia-induced canine cardiac model was used to study the effectiveness hemodynamic response, arterial blood gas and pulmonary pathologic changes after endotracheal (ET) epinephrine administration in comparison with those from intravenous (IV) administration. The results indicated that the survival rate was the same with the drug given by either route. The increase of hemodynamic indices was lower in the group after ET administration than that after IV administration. No significant influence was exerted on the drug effects whether the drug is diluted in normal saline or in distilled water and no serious detrimental effects occurred on the lung tissues following ET epinephrine administration.

Similarities in surface lipids of chylomicrons from glyceryl and alkyl ester feeding: major components

This study tests the hypothesis that the rat chylomicrons are assembled and released into lymph similarly regardless of the site (rough or smooth endoplasmic reticulum) or pathway (phosphatidic acid or monoacylglycerol) of triacylglycerol biosynthesis. For this purpose we determined the lipid class, fatty acid and molecular species composition of the choline, ethanolamine, inositol and serine phospholipids of lymph chylomicrons during absorption of menhaden, mustard-seed and corn oil (monoacylglycerol pathway) or the corresponding fatty acid methyl or ethyl esters (phosphatidic acid pathway). The dietary fatty acids were found to be incorporated to various extents into different phospholipid classes, the proportions of which were not affected by the nature of the dietary fat. The chylomicron phospholipids contained 80-82% choline, 8% ethanolamine and 2.5% inositol glycerophospholipids, and much smaller amounts of serine and other minor phospholipids. Administration of a meal of each dietary fat resulted in a retention of approximately 50% endogenous fatty acids in the major glycerophospholipids of the chylomicrons. A minimum of 50% of the molecular species of the choline and ethanolamine glycerophospholipids contained at least one exogenous fatty acid. No significant discrepancies were found in the fatty acid and molecular species composition of the glycerophospholipids between chylomicrons from the oil and corresponding ester feeding. It is concluded that the chylomicrons arising from the monoacylglycerol (oil feeding) and the phosphatidic acid (ester feeding) pathways of triacylglycerol biosynthesis become enveloped in surfactant monolayers containing qualitatively and quantitatively identical classes and molecular species of phospholipids.

Apparent convergence (at 2-monoacylglycerol level) of phosphatidic acid and 2-monoacylglycerol pathways of synthesis of chylomicron triacylglycerols

Dietary fats are converted into chylomicron triacylglycerols via the 2-monoacylglycerol and phosphatidic acid pathways of acylglycerol formation. In view of the known positional and fatty acid specificity of the acyltransferases, the triacylglycerol structures resulting from the two pathways would be expected to differ, but this has not been demonstrated. We have performed stereospecific analyses on the chylomicron triacylglycerols from rats fed menhaden oil and the corresponding fatty acid alkyl esters, which would be expected to be assimilated via the monoacylglycerol and the phosphatidic acid pathways, respectively. The results show a remarkable similarity between the two triacylglycerol types in the fatty acid composition of the sn-1 and sn-3 positions, along with marked differences in the composition of the sn-2 positions. The triacylglycerols from rats fed oil retained about 85% of the original fatty acids in the sn-2 position, including a high proportion of the long chain polyunsaturates (e.g., 5-7% 20:5 and 4-5% 22:6). The triacylglycerols from rats fed the alkyl ester contained large amounts of endogenous fatty acids in the sn-2 position (e.g., 18% 16:1, 14% 18:1, 14% 18:2, and 2.5% 20:4), which approximated the composition of the sn-2 position of the presumed phosphatidic acid intermediates. The sn-1 position contained a much higher proportion of polyunsatured fatty acids (e.g., 12-13% 20:5, 5-6% 22:6) than the sn-2 position (e.g. 2-3% 20:5, 0-0.6% 22:6) of triacylglycerols from rats fed the ester. We conclude that the chylomicron triacylglycerols arising via the 2-monoacylglycerol and the phosphatidic acid pathways differ mainly in the composition of the fatty acids in the sn-2 position. The similarity in the acids of the sn-1 and sn-3 positions of the chylomicron triacylglycerols from rats fed oil or ester is consistent with a hydrolysis of the acylglycerol products of the phosphatidic acid pathway to 2-monoacylglycerols prior to reconversion to triacylglycerols via the monoacylglycerol pathway and secretion as chylomicrons.

Heterogeneous effects of interferon on antitumor agents' cytotoxicities to human colon carcinoma cell lines

Six established human colon carcinoma cell lines that segregated into three groups with different degrees of differentiation were treated using three subclasses of interferons as single agents and in combination with either 5-fluorouracil, cis-platinum, or adriamycin. The cytotoxicities of the combination treatments were heterogeneous and did not relate to the cell's levels of differentiation. Our data suggest that the optimal combinations of interferons and chemotherapeutic agents are independent of the differentiation state of the colon cancer cells.

Surface array proteins of Campylobacter fetus block lectin-mediated binding to type A lipopolysaccharide

Campylobacter fetus strains with type A lipopolysaccharide (LPS) and a surface array protein layer (S+) have been found to be pathogenic in humans and animals. Spontaneous laboratory mutants that lack surface array proteins (S-) are sensitive to the bactericidal activity of normal human serum. The ability of lectins to determine the presence of the S-layer and differentiate LPS type was assessed. We screened 14 lectins and found 3 (wheat germ agglutinin, Bandeiraea simplicifolia II, and Helix pomatia agglutinin) that agglutinated S- C. fetus strains with type A LPS but not S- strains with type B or type C LPS or S+ strains. However, the S+ type A strains were agglutinated after sequential water extraction, heat, or pronase treatment, all of which remove the S-layer, whereas there was no effect on the control strains. Specific carbohydrates for each lectin and purified LPS from a type A C. fetus strain specifically inhibited agglutination of an S- type A strain. In a direct enzyme-linked lectin assay, binding to the S- type A LPS strain was significantly greater than binding to the S+ strain (P = 0.01) or to a Campylobacter jejuni strain (P = 0.008). Consequently, these results indicate that the three lectins bind to the O side chains of C. fetus type A LPS but that the presence of the S-layer on intact cells blocks binding.

Biological characterization of multidrug-resistant human colon carcinoma sublines induced/selected by two methods

Two independent multidrug-resistant (MDR) sublines, AdR1.2 and SRA1.2, were developed from the established human colon carcinoma cell line LoVo. AdR1.2 was developed by a long-term continuous exposure of LoVo cells to Adriamycin in stepwise increments of concentration; SRA1.2 was selected/induced by pulse treatments by using a single concentration of Adriamycin. The two resistant sublines were cross-resistant and cross-sensitive to a similar spectrum of cytotoxic agents. However, AdR1.2 was most resistant to Adriamycin among the nine agents tested, and SRA1.2 was most resistant to Vinca alkaloids. Although SRA1.2 had biological characteristics similar to those of LoVo, AdR1.2 had remarkably altered biological properties, including no detectable carcinoembryonic antigen secretion, a smaller proportion of proliferating cells and a lower growth rate, lower fraction of cells in S phase, a lower colony-forming ability, and smaller colonies. In addition, the resistant phenotype of AdR1.2 was reversed when the cells were grown in a drug-free medium, whereas SRA1.2 maintained its resistance for at least 10 months under similar conditions. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the plasma membrane proteins demonstrated overproduction of an Mr 130,000 protein in both the resistant sublines. The Mr 130,000 protein was not immunoreactive with C219 monoclonal antibody against p170, but the absence of Mr 130,000 protein in an AdR1.2 revertant and the parental LoVo suggests that it is an MDR-related plasma membrane protein. The absence of a 46-kDa cytosolic protein and the presence of a Mr 150,000 plasma membrane protein were found in AdR1.2 but not in SRA1.2. This Mr 150,000 protein immunoreacted with C219. This protein was also present, although in a reduced amount, in an AdR1.2 revertant that retained three times the MDR of LoVo cells and was thus comparable to SRA1.2. The two MDR sublines thus may represent two independent subclones which may serve as two different models for the study of multidrug resistance in human colon cancer.

Intestinal absorption of menhaden and rapeseed oils and their fatty acid methyl and ethyl esters in the rat

The relative cellular uptake and incorporation into prechylomicrons and chylomicrons was investigated for the menhaden and rapeseed oil fatty acids, when given by stomach tube as the original oils or the corresponding methyl and ethyl esters. The intermediates and final products of cellular acylation were determined by chromatographic methods at various times over a period of 1-24 h. There was little selectivity in the uptake among the oligo- and poly-unsaturated fatty acids of menhaden oil, when either oil or esters were fed. In contrast, the long-chain saturated and monounsaturated fatty acids of rapeseed oil were discriminated against during both cellular uptake and reacylation (60% overall reduction in utilization). Also, there was detectable discrimination against the long-chain polyunsaturated monoacylglycerols of menhaden oil and against the long-chain saturated and monounsatured monoacylglycerols of rapeseed oil during both cellular uptake and reacylation (30% overall reduction in utilization). Evidence was obtained for an indiscriminate cellular uptake of variable amounts (4-22%) of intact dietary methyl and ethyl esters of fatty acids, which, however, appeared in the chylomicrons only to a very limited extent (0.1-1.0% of total lipid). During peak absorption the cellular and lymphatic appearance of fatty acids from the digestion and absorption of the alkyl esters was nearly 50% lower than that from the corresponding triacylglycerols. The slower absorption of the fatty acids from the alkyl ester feeding is hypothetically attributed to a lower efficiency of the phosphatidic acid pathway, which is required in the absence of dietary 2-monoacylglycerols, but other mechanisms cannot be excluded.

Lipolysis of menhaden oil triacylglycerols and the corresponding fatty acid alkyl esters by pancreatic lipase in vitro: a reexamination

In order to distinguish between possible fatty acid differences during lumenal lipolysis and cellular absorption, we have reinvestigated the in vitro hydrolysis of menhaden oil and its alkyl esters by pancreatic lipase. For this purpose we incubated menhaden oil or its fatty acid methyl and ethyl esters with porcine pancreatic lipase in the presence of bile salts and determined the composition of the released free fatty acids, monoacylglycerols, diacylglycerols, and residual triacylglycerols, or the free fatty acids and residual alkyl esters, respectively, by thin-layer and gas-liquid chromatography. There was significant discrimination against the delta 4- to delta 7-unsaturated fatty acids of both medium and long chain lengths during the hydrolysis of menhaden oil and its fatty acid ethyl esters. In general, the ethyl esters were hydrolyzed 10-50 times more slowly than the corresponding glyceryl esters, depending on the exact ratio of the two substrate types. None of the triacylglycerols or ethyl esters, however, was completely resistant to hydrolysis resulting in an eventual cleavage of all the alkyl esters and presumably all the primary ester bonds in the triacylglycerol molecules. Since the rate of release of the least resistant fatty acid exceeded that of the most resistant acid by only a factor of 6, it is concluded that in the presence of a large excess of lipase the liberated fatty acids would approach the composition of the dietary alkyl or glyceryl esters, as observed during lumenal lipolysis (Yang, L.-Y., A. Kuksis, and J. J. Myher. 1989. Biochem. Cell Biol. 67: 192-204).

Metronidazole enhances the cytotoxic synergism produced by the combination of 1-beta-arabinofuranosylcytosine and cis-diamminedichloroplatinum

Metronidazole (MZ) was evaluated as a single agent or in combination with CDDP and araC for its cytotoxic effects on five established human colon carcinoma cell lines. MZ alone produced little cytotoxicity at 1 h drug incubation. The cytotoxicity was detectable only after 2 h incubation and increased as a function of duration of treatment, suggesting a time-dependent rather than a dose-dependent cytotoxic effect. MZ had no effect on CDDP- or araC-induced cytotoxicity, whereas MZ enhanced the synergism resulting from the combination of two antitumor agents on the human colon tumor cell lines tested. Such enhancement was more pronounced on cells growing in stationary rather than in exponential phase. MZ not only produced a reversible S-phase arrest but also lessened the CDDP-produced inhibition on the incorporation of araC into DNA. However, it did not enhance CDDP-induced DNA cross-linkings, with or without araC. Our results indicated that MZ enhanced the synergism produced by two antitumor drugs in combination and that enhancement was accompanied by an increase in S-phase population and of the incorporation of araC into nucleic acids.