[Successful 48-72 h cold storage of dog kidneys with HX-1 solution]

HX-1 solution was used in this study to determine its effects on long term kidney preservation. 20 female and male mongrel dogs were randomly divided into control (HC-WCU solution) and experimental (HX-1 solution) groups. Kidneys were flushed with HC-WCU or HX-1 solution and stored at 0.4 degree C for 48 or 72 h. After being preserved, the kidney was implanted in the right groin of the animal and anastomosed to the iliac vessles. This procedure was immediately followed by a contralateral nephrectomy. The experimental findings were: 1. The maximum serum creatinine levels were 642.60 +/- 158.60 mumol/L and 686.20 +/- 154.04 mumol/L respectively in HC-WCU solution subgroups for 48 or 72 h cold storage. But the maximum serum creatinine levels were 448.32 +/- 36.90 mumol/L and 524.60 +/- 109.38 mumol/L respectively in HX-1 solution subgroups. 2. 80% of the kidneys were viable after 48 h storage in HC-WCU kidney solution, but 100% viable when stored in HX-1 solution: 40% of the kidneys were viable after 72 h storage in HC-WCU solution, but 60% viable when stored in HX-1 solution. 3. Histologically the kidney of dogs that died of renal failure was damaged worse in HC-WCU solution group than that in HX-1 solution group. These results suggest that HX-1 solution is superior to HC-WCU solution for preserving kidneys and HX-1 solution may store up the kidney of dogs to 48-72 h.

Blood-retinal barrier (BRB) breakdown in experimental autoimmune uveoretinitis: comparison with vascular endothelial growth factor, tumor necrosis factor alpha, and interleukin-1beta-mediated breakdown

Experimental autoimmune uveoretinitis (EAU) induced in Lewis rats by immunization with S-antigen is a model of human uveitis. By using immunocytochemical staining for albumin, relatively minor blood-retinal barrier (BRB) breakdown was initially shown in the peripheral retina 8 days after immunization and in the posterior retina by 10 days. Albumin extravasation appeared to occur by opening of the retinal vascular endothelial (RVE) and the retinal pigmented epithelial (RPE) tight junctions, by transendothelial vesicular transport, and by permeating damaged RVE cells. Each of three anti-inflammatory agents reduced or delayed autoimmune-mediated cell destruction but did not eliminate any particular route of extravasation. Vascular endothelial growth factor (VEGF), tumor necrosis factor alpha (TNF alpha), and interleukin-1beta (IL-1beta) are intimately associated with the development of EAU and are capable of causing BRB dysfunction. A high percentage of RVE tight junctions appeared open ultrastructurally after intravitreal injection of VEGF (26.7%), TNF alpha (35.6%), or IL-1beta (22.1%) compared with saline-injected control (11.4%) or normal, untreated rabbits (4.1%). Heat treatment abolished the effect of IL-1beta on the BRB but only partially reduced the effect of VEGF. By 24 hr after injection, the effect of TNF alpha had reversed, but that of IL-1beta had not; VEGF-mediated BRB dysfunction was partially reversible. In addition, albumin-filled vesicle-like structures were seen in the RVE cytoplasm following treatment with each mediator. This study shows that VEGF, TNF alpha, and IL-1beta each cause BRB breakdown by opening tight junctions between RVE cells and possibly by increasing transendothelial vesicular transport. Each of these agents may contribute to BRB breakdown in EAU and in patients with uveitis.

Kinin generation in acute pneumonia and chronic bronchitis

Kinins are potent inflammatory mediators, liberated from kininogens by different kininogenases. The aim of this study was to investigate the kinin generation pathways in acute and chronic inflammation of the lower airways. We studied bronchoalveolar lavage fluid (BALF) of patients with acute pneumonia, patients with chronic bronchitis and healthy controls. Kinins were determined by radioimmunoassay (RIA). Plasma kallikrein (pl-Kal), alpha2-macroglobulin (alpha2-M) and toluenesulphonylarginine methyl ester (TAME) esterase activity (TAME-ea) were studied in BALF before and after gel filtration chromatography. Plasma kallikrein and alpha2-M were measured using two newly developed sandwich enzyme-linked immunosorbent assays (ELISAs). TAME-ea was measured by a radiochemical assay. After gel filtration, inhibition of TAME-ea with benzamidine, soy-bean-trypsin inhibitor (SBTI) and aprotinin was performed. Kinins and TAME-ea did not differ significantly between acute pneumonia and chronic bronchitis, whereas pl-Kal and alpha2-M values were significantly higher in acute pneumonia. Gel filtration revealed the highest TAME-ea peak in acute pneumonia corresponding with the first alpha2-M peak at approximately 800 kDa, whereas in chronic bronchitis the highest peak was found at approximately 40 kDa. The inhibition test showed that the TAME-ea peak at approximately 800 kDa was due to pl-Kal and the TAME-ea peak at approximately 40 kDa was mainly due to tissue kallikrein. High peaks of alpha2-M and pl-Kal were found in pneumonia and only small peaks were seen in chronic bronchitis. We conclude that in acute airway inflammation kinins seem to be mainly generated by plasma kallikrein whereas in chronic inflammation, kininogenases other than plasma kallikrein, such as tissue kallikrein, seem to be more important.

Delivery of oligoribonucleotides to human hepatoma cells using cationic lipid particles conjugated to ferric protoporphyrin IX (heme)

The receptor-ligand interaction between hepatocyte heme receptors and heme was evaluated as a basis for developing a targeted cationic lipid delivery reagent for nucleic acids. Heme (ferric protoporphyrin IX) was conjugated to the aminolipid dioleoyl phosphatidylethanolamine (DOPE) and used to form cationic lipid particles with dioleoyl trimethylammonium propane (DOTAP). These lipids particles (DDH) protect oligoribonucleotides from degradation in human serum and increase oligoribonucleotide uptake into 2.2.15 human hepatoma cells (to a level of 50-60 ng oligo/10(4) cells) when compared with the same lipid particles (DD) prepared identically without heme. The DDH heme level that was optimal for oligoribonucleotide delivery was also optimal for maximum expression of plasmid-encoded luciferase. The enhancing effect of heme was evident only at net particle negative charge. Fluorescence microscopy showed that DDH delivered oligoribonucleotides into both the 2.2.15 cell cytoplasm and nucleus. DDH may thus be a potentially useful delivery vehicle for oligonucleotide-based therapeutics and transgenes, appropriate for use in such liver diseases as viral hepatitis, hepatoma, and hypercholesterolemia.

Changes in oral health knowledge and behaviour 1987-95 among inhabitants of Wuhan City, PR China

The purpose of this study was to evaluate the changes of oral health knowledge and behaviour among Wuhan citizens after six years of 'Love Teeth Day' campaigns. Representative samples of citizens aged 10-62 years were identified and interviewed in 1987 (n = 1180) and in 1995 (n = 1014). Data on oral health knowledge and practises were collected by structured questionnaires in both surveys and high response rates were obtained (87-94 per cent). In general, improvements in oral health knowledge and toothbrushing behaviour were observed in 1995 as compared with 1987. The younger age group (10-19-year-olds) showed significantly higher improvements of positive answers to knowledge items and toothbrushing behaviour. The findings also indicated that less than half of the interviewees were aware of the anti-caries effect of fluoride and about 30 per cent of the participants brushed their teeth performing the recommended method (vertical). In China, community based oral health education programmes should be implemented to further improve regular self-care practises, especially in relation to the adult population.

Central thromboxane receptors: mRNA expression and mediation of pressor responses

These studies tested whether activation of central thromboxane (Tx)A2/prostaglandin (PG) H2 receptors raises blood pressure (BP). Messenger RNA for TxA2/PGH2 receptors was detected in normal Sprague-Dawley rat brain and in rat neuronal and astroglial brain cells in culture. The mean arterial blood pressure (MAP) was recorded in conscious rats during graded administration of the TxA2/PGH2 receptor agonist U-46,619 given intracerebroventricularly or intravenously. Because the pressor responses to intracerebroventricular (but not intravenous) U-46,619 were significantly greater in-high-salt compared with low-salt rats, high-salt rats were used for subsequent studies. The rise in MAP with intracerebroventricular administration of U-46,619 was greater than with intravenous administration and was more sustained. A comparison of plasma radioactivity after intracerebroventricular or intravenous injection of [3H]U-46,619 demonstrated that approximately 35% of the drug reached the systemic circulation by 5-15 min after intracerebroventricular administration. Coadministration of a TxA2/PGH2 antagonist, ifetroban, by intravenous or intracerebroventricular routes blocked the pressor responses induced by U-46,619. The half-maximal inhibition for blockade of responses was substantially lower for intracerebroventricular than for intravenous responses (intracerebroventricular: 0.03 +/- 0.01 vs. intravenous: 3.1 +/- 0.6 micrograms/kg; P < 0.001). The intravenous administration of ifetroban (10 micrograms/kg) caused a greater (P < 0.02) inhibition of pressor responses to U-46,619 (1 microgram/kg) given intravenously (81 +/- 3%) compared with U-46,619 given intracerebroventricularly (40 +/- 13%). In conclusion, TxA2/PGH2 receptor mRNA is expressed in neurons, glial, and brain stem of normal rats. The central administration of a TxA2/PGH2 mimetic raises blood pressure by interaction with specific central and peripheral receptors. This response is augmented in rats fed a high-salt compared with a low-salt diet.

Characterization of liposome-mediated gene delivery: expression, stability and pharmacokinetics of plasmid DNA

We have characterized a new synthetic gene delivery system, termed DLS, which may be suitable for systemic gene therapy. DLS constitutes a lipopolyamine and a neutral lipid and associated plasmid DNA in the formation of lamellar vesicles (DLS-DNA). The ratio of lipids and lipid to DNA as well as the method of preparation were optimized to yield a high in vitro transfection efficiency compared with that previously reported for cationic lipid systems. DLS-DNA showed a rapid cellular uptake and distribution in the cytoplasmic and nuclear (especially in the nucleoli) compartments as determined by laser-assisted confocal microscopy. There was little or no plasmid DNA degradation over a period of 20 min, relatively slow plasma clearance, and effective and rapid cellular uptake of DLS-DNA following intravenous administration in mice. Supercoiled plasmid DNA could be detected in blood cells up to 1 h after injection. Systemic administration of DLS-DNA yielded transgene expression in mouse tissues, such as in lung or liver. The ratio of DLS:DNA and the procedure used to form DLS-DNA affected both the level and cellular specificity of expression of a luciferase reporter gene showing that in vitro transfection efficiency of DLS-DNA formulations cannot be easily extrapolated to an in vivo setting. Optimization of the formulation of a DNA delivery system was critical to obtain a defined structure resulting in a preparation with high reproducibility and stability, greater homogeneity of particle size and high efficacy following systemic gene transfer. In addition, the DLS system may be formulated for specific target tissues and may have a wide range of applications for gene therapy.

Upregulation of vascular endothelial growth factor in ischemic and non-ischemic human and experimental retinal disease

Vascular endothelial growth factor (VEGF) is induced by hypoxia and it has been implicated in the development of iris and retinal neovascularization (NV) in ischemic retinopathies in which it has been suggested that Muller cells are responsible for increased VEGF production. VEGF, however, is also known to be a potent mediator of vascular permeability in other tissues and may perform this function in retina. Immunohistochemical staining for VEGF was performed on a variety of human and experimental ischemic and non-ischemic ocular disorders in which blood retinal barrier (BRB) breakdown is known to occur to determine if there is an upregulation of VEGF in these conditions. We found increased VEGF immunoreactivity in ganglion cells of rats with oxygen-induced ischemic retinopathy and in ganglion cells, the inner plexiform layer, and some cells in the inner nuclear layer of rats with experimental autoimmune uveoretinitis (EAU), in which there was no identifiable ischemia or NV. In rats with EAU, VEGF staining intensity increased from 8 to 11 days after immunization, coincident with BRB failure. These results were confirmed using two distinct anti-VEGF antibodies and by immunoblot and the immunohistochemical staining was eliminated by pre-incubating the antibodies with VEGF peptide. VEGF staining was also increased in the retina and iris of patients with ischemic retinopathies, such as diabetic retinopathy and retinal vascular occlusive disease, and in patients with disorders in which retinal ischemia does not play a major role, such as aphakic/ pseudophakic cystoid macular edema, retinoblastoma, ocular inflammatory disease or infection, and choroidal melanoma. VEGF was primarily localized within retinal neurons and retinal pigmented epithelial cells in these cases. In addition or in association with its role of inducing NV, VEGF may contribute to BRB breakdown in a variety of ocular disorders and blockage of VEGF signaling may help to reduce some types of macular edema.

Platinum-DNA adduct formation in leucocytes of children in relation to pharmacokinetics after cisplatin and carboplatin therapy

Platinum (Pt)-DNA adducts were measured in peripheral blood leucocytes (PBLs) from 24 children with solid tumours after standard cisplatin and/or carboplatin treatment. The relationship between Pt-DNA adduct levels and pharmacokinetics of cisplatin and carboplatin was investigated. Adduct measurements were performed by competitive enzyme-linked immunosorbent assay (ELISA) and plasma unbound Pt concentrations were measured by atomic absorption spectrophotometry (AAS). There was considerable interindividual variation in Pt-DNA adduct level that was weakly correlated (r2 = 0.32) with the area under the unbound drug concentration vs time curve (AUC) at 6 h after the start of cisplatin infusion, indicating that the variation in Pt-DNA adduct levels was primarily determined by factors other than AUC. No clear relationship between AUC and adduct levels was seen at 24 and 48 h after cisplatin or at 6, 24 or 48 h after carboplatin. Carboplatin produced lower levels of immunoreactive adducts than did cisplatin (1.3 +/- 0.6 nmol Pt g-1 DNA vs 3.2 +/- 1.7 nmol Pt g-1 DNA), despite a 20-fold higher unbound drug AUC for carboplatin (8.0 +/- 3.5 mg ml-1 min vs 0.4 +/- 0.2 mg ml-1 min). This study demonstrates that, after cisplatin and carboplatin treatment the drug-target interaction is determined by both pharmacokinetic and, predominantly, cellular factors. Intrinsic differences between the two complexes, primarily reactivity, probably explain the lower adduct levels observed after carboplatin treatment.

Effect of transforming growth factor beta-1 in endotoxin-induced uveitis

PURPOSE

Transforming growth factor beta-1 (TGF beta-1) can modulate inflammation. Endotoxin-induced uveitis (EIU) is characterized by acute ocular inflammation related to the release of cytokines, including interleukin (IL)-6. The authors investigated the effect of TGF beta-1 on EIU in mice.

METHODS

Three independent experiments were performed. Endotoxin-induced uveitis was induced in C3H/HeN mice by an injection of 200 micrograms of lipopolysaccharide (LPS). Two micrograms of TGF beta-1 in 0.1 ml phosphate-buffered saline (PBS) or 0.1 ml PBS alone was administered intraperitoneally at 8 hours after LPS injection. Twenty-four hours after LPS injection, the aqueous humor of the right eyes was collected for leukocyte count, protein concentration, and IL-6 assay. Left eyes were processed for routine histology.

RESULTS

TGF beta-1-treated mice showed less ocular inflammation histologically than to the animals that were given PBS. This was confirmed by decreases in leukocyte count, protein concentration, and IL-6 level in the aqueous humor.

CONCLUSIONS

TGF beta-1 inhibits the development of EIU. TGF beta-1 may be useful for the modulation of uveitis in humans.

Phosphorylation events associated with different states of activation of a hepatic cardiolipin/protease-activated protein kinase. Structural identity to the protein kinase N-type protein kinases

Cardiolipin- or protease-activated protein kinase, isolated from rat liver cytosol and originally named liver PAK-1, was found to be the natural form of protein kinase N (PKN) by comparing the sequences of 43 tryptic peptides of the purified liver enzyme and determining the corresponding liver cDNA sequence. These analyses also identified (i) Arg-546 as the major site of proteolytic activation, (ii) the protease resistance of the C-terminal extension beyond the catalytic domain, and (iii) in vivo stoichiometric phosphorylation of Thr-778 in the mature enzyme. Homology modeling of the catalytic domain indicated that phosphothreonine 778 functions as an anchoring site similar to Thr-197 in cAMP-dependent protein kinase, which stabilizes an active site compatible with preferred substrate sequences of PAK-1/PKN. Sigmoidal autophosphorylation kinetics and increased S6-(229-239) peptide kinase activity following preincubation with ATP suggested phosphorylation-dependent activation of PAK-1/PKN. The onset of activation corresponded with phosphorylation of the regulatory domain site Ser-377 (located within a spectrin homology region), followed by Thr-504 (within a limited protein kinase C homology region), and, to a lesser extent, Thr-64 (in the RhoA-binding region). Several additional sites in the hinge region adjacent to a PEST protein degradation signal were selectively autophosphorylated following cardiolipin activation. Overall, these observations suggest that the regulation of this class of protein kinase involves complex interactions among phosphorylation-, lipid-, and other ligand-dependent activation events.

Population pharmacokinetics of carboplatin in children

OBJECTIVES

In pediatric patients, administration of carboplatin according to body surface area results in a large variation in the area under the plasma ultrafilterable carboplatin concentration versus time curve. A population pharmacokinetic study using the NONMEM program was undertaken to determine the effects of a variety of covariates on the clearance of ultrafilterable carboplatin.

PATIENTS

Plasma carboplatin pharmacokinetics were determined in 57 children (2 months to 18 years old, with serum creatinine levels ranging from 27 to 268 mumol/L) treated for various tumor types.

RESULTS

The best fit corresponded to the formula: clearance (ml/min) = 2.85.weight.(1-0.00357.serum creatinine).(1-0.372.Np) + 8.7 (with serum creatinine in micromoles per liter, weight in kilograms, and Np = 1 or 0 for unilateral nephrectomy or not, respectively). The interindividual variability in clearance, as expressed by the coefficient of variation, decreased from 74% (no covariates) to 49% by taking account of weight, and to 29% under the final regression formula.

CONCLUSION

The ability of this formula to predict carboplatin clearance in children should be evaluated prospectively and compared to a method based on the determination of the glomerular filtration rate.

Pharmacokinetically guided dosing of carboplatin and etoposide during peritoneal dialysis and haemodialysis

Two patients with relapsed Wilms' tumour and renal failure requiring dialysis were given carboplatin and etoposide by pharmacokinetically guided dosing. The target area under the drug plasma concentration vs time curve (AUC) was 6 mg ml-1 min for carboplatin and 18 and 21 mg ml-1 min for etoposide. On course 1 measured AUCs of carboplatin and etoposide were 6 and 20 mg ml-1 min for patient 1 and 6 and 21 mg ml-1 min for patient 2 respectively. Peritoneal dialysis did not remove carboplatin or etoposide from the plasma, however carboplatin but not etoposide was cleared by haemodialysis. Therapy with carboplatin and etoposide is possible in children and adults with renal failure who require dialysis, but in this situation pharmacokinetic monitoring is essential.

The eyes of transforming growth factor-sZ1 (TGF-sZ1) transgenic mice Morphology and the development of endotoxin-induced uveitis

Transforming growth factor-beta (TGFsZ) is a potent regulator of cellular growth and immune function. The authors studied ocular histology and endotoxin-induced uveitis in a TGF-sZ(1) transgenic (Tg) murine model. TGF-sZ(1) Tg mice were generated by micro injecting a gene constructed by fusing the mouse albumin enhancer/promoter and porcine TGF-sZ(1) cDNA. The eyes of Tg mice from two to 14 weeks of age were studied histologically. Tg mice, two to five weeks of age exhibited mild fragmentation of the lens fibers and retinal edema. No pathology was found from six to ten weeks of age, however, a progressive increased frequency of cataract was observed from 11 to 14 weeks of age. Plasma TGF-sZ(1) levels were much higher in Tg mice than age-matched wild type control littermates (wt). Endotoxin-induced uveitis (EIU) in six-to eight-week-old Tg and wt mice was induced by footpad injection of lipopolysaccharide (LPS). Mice were euthanized 24 hr after LPS injection, the eyes were collected for histology and serum assayed for IL-6 and TGF-sZ(1). There was a decrease in the mean numbers of infiltrating cells in Tg mice compared to wt mice. Serum IL-6 and TGF-sZ(1) were much higher in Tg mice. The authors concluded that expression of the TGF-sZ(1) transgene in the eyes may have effect on lens growth. Overexpression of TGF-sZ(1) results in little or no effect on the development of EIU.

Endotoxin induced uveitis in the mouse: susceptibility and genetic control

Endotoxin induced uveitis in the mouse provides a useful animal model for acute anterior uveitis in humans. We have investigated the susceptibility of endotoxin-induced uveitis among various mouse strains, and have examined the relationship between genetic background and the resultant inflammatory response to endotoxin. We studied ten strains with differing major histocompatibility-2 genes, lipopolysaccharide response gene, and strains with mast cell depletion and its sham control. Anterior uveitis was induced by injecting 300 micrograms of Salmonella typhimurium endotoxin into one hind footpad. Mice were then killed 8, 12, 16, 20, 24, 48 and 72 hr after endotoxin injection, and vertical sections of the eyes through the pupil-optic nerve axis were evaluated for ocular inflammation. C3H/HeN mice developed severe uveitis. In contrast, C3H/HeJ mice (lipopolysaccharide response gene-) did not develop uveitis even though it has the same genetic background and shares the same major histocompatibility-2 haplotype with C3H/HeN mice (lipopolysaccharide response gene+). The strain that was mast-cell deficient (W/Wv) developed minimal uveitis; however, W/+ mice, with mast cells, developed more inflammation at 48 and 72 hr after endotoxin injection. C3H.SW and FVB/N mice also developed severe uveitis, and BALB/C, CBA/J, and B10.A developed mild uveitis. In conclusion, there is a wide variation in the magnitude and susceptibility to endotoxin among mouse strains. Multiple factors appear to influence this variability, including non-histocompatibility-2 genetic background, the lipopolysaccharide response gene, and the presence of mast cells.

Comparison of methods for the estimation of carboplatin pharmacokinetics in paediatric cancer patients

The antitumour and toxic effects of platinum drugs, in particular carboplatin, have been related to their plasma concentration and this has led to the concept of a target area under the plasma concentration-time curve (AUC) for carboplatin dosing. A formula based on renal function has been successfully applied to carboplatin dosing in adults and modified versions have also been proposed for paediatric patients. In order to monitor carboplatin AUC with maximum efficiency and minimum patient inconvenience, limited sampling strategies are desirable. A population method with Bayesian estimation is described, based on one or two samples taken following a dose of carboplatin. Population data were obtained from 22 paediatric patients treated with 200-1000 mg/m2 carboplatin as a 60-90 min infusion. Ultrafilterable carboplatin was determined by atomic absorption spectrophotometry. A two compartment model was fitted to each data set using the Maximum Likelihood estimator of the ADAPT programme. These parameter estimates provided the prior means and covariance matrix for the Bayesian estimator using a lognormal distribution. The test data sets consisted of ultrafilterable carboplatin concentrations in 23 patients (aged 1 month-18 years) who received similar treatment. The two compartment model was fitted to data sets containing one or two points, using the Bayesian maximum a posteriori (MAP) estimator and an error model derived from the population error model parameters. Results from the Bayesian analysis and other methods for the estimation of AUC, including relating clearance to surface area or to renal function, were evaluated by comparing the AUC estimate with the AUC determined by model-independent analysis. Overall, the optimal sampling strategy performed better than estimates based on renal function, which had a median bias of 5% and precision of 22%. With one data point at 60 min postinfusion, the median bias and precision were 3 and 6%, respectively. Addition of a second data point at 30 min during the infusion improved the estimate slightly (median bias -2%, precision 3%). Bayesian estimation produced more reliable estimates of AUC compared to values based on renal function, which in turn was slightly better than using surface area. A technique, developed in adult patients, for estimating AUC from a measurement of 24 h total plasma platinum was comparable to estimates based on renal function, but was less reliable. The estimation of carboplatin AUC can be performed using only one or two plasma samples and Bayesian analysis. This approach is less biased and more precise than methods based on surface area, renal function or total platinum at 24 h postdose, but is probably best used in combination with dosing based on renal function.

[Effects of gu chi san on cultured human gingival fibroblasts]

The present study demonstrates that Gu Chi San is able to increase the bone density in the clinical and animal tests. This study finds that Gu Chi San has no cytotoxicity on HGFs, and 1g/L Gu Chi San extracts can stimulate the mitosis and enhance the DNA synthesis of HGFs. The results indicate that certain substances are present in Gu Chi San.

Growth inhibition of malignant CD5+B (B-1) cells by antisense IL-10 oligonucleotide

Malignant B-1 cells derived from NZB mice, a murine model of chronic lymphocytic leukemia, produce significantly higher levels of IL-10 mRNA than normal B-1 or B cells. IL-10 may act as an autocrine growth factor for malignant B-1 cells. By addition of antisense oligodeoxynucleotides specific for IL-10 mRNA, we were able to dramatically inhibit the growth of leukemic B-1 cells in a time and dose dependent manner. Control cell lines which do not depend on IL-10 for growth were not affected. Antisense therapy targeted at the 5' region of the IL-10 mRNA not only resulted in inhibition of malignant B-1 cell proliferation but also inhibited IL-10 production by malignant B-1 cells. Because endogenous IL-10 gene activation is critical for B-1 cell expansion, inactivation of the endogenous IL-10 gene by IL-10 antisense rather than extracellular regulation of the IL-10 gene product should be successful in controlling the malignant growth.

An autoregulated dual-function antitat gene for human immunodeficiency virus type 1 gene therapy

One approach to gene therapy for AIDS is to block the replication of human immunodeficiency virus type 1 (HIV-1) by inhibiting that tat gene, whose product activates the expression of all HIV-1 genes. To accomplish this, we constructed an antitat gene expressing an RNA with dual (polymeric TAR and antisense-tat) function in an attempt to both sequester Tat protein and block its translation from mRNA. A minigene consisting of the antitat gene driven by the HIV-1 long terminal repeat was inserted into a double-copy retrovirus vector, such that antitat expression would be upregulated only in HIV-1-infected cells. After transduction of a T-lymphocytic cell line (Molt-3) the antitat gene inhibited HIV-1 replication. This inhibition was inversely correlated with the virus infections dose. Virus replication was also inhibited for 5 months in two different T-cell lines after they had been infected at a high multiplicity of infection, suggesting that the antitat gene may be effective over long periods. Importantly, antitat blocked the replication and the cytopathic effect of HIV-1 in human peripheral blood mononuclear cells and led to as much as 4,000-fold inhibition of the replication of an HIV-1 field isolate as well as HIV-1 prototypes maintained in culture. These results suggest that antitat gene therapy has potential use for blocking HIV-1 replication in infected individuals.

A cultured malignant B-1 line serves as a model for Richter's syndrome

Human chronic lymphocytic leukemia (CLL) is a malignancy of B-1 cells characterized by the accumulation of mature appearing, long lived, slow growing B-1 cells in peripheral blood. CLL occasionally evolves into an aggressive large cell lymphoma termed Richter's syndrome. NZB mice can be used to model the early stage of CLL because aged NZB mice can spontaneously develop slow growing malignant B-1 cell clones. The malignant NZB B-1 clones fail to grow in culture and are typically carried in vivo as passaged lines. During serial passage, an aggressive lymphoma developed as a result of a continued transformation of the original B-1 clone, similar to the development of Richter's syndrome. An in vitro cell line was established from the aggressive lymphoma, which was stromal dependent and could rapidly metastasize when passaged into recipient animals. Analysis of adhesion molecules did not reveal any consistent characteristics that could account for the metastatic potential of the Richter's-like cells. In addition, the aggressive in vitro line had the identical heavy chain sequence as the slow growing NZB malignant B-1 clones. The in vitro and in vivo aggressive B-1 cells had very high levels of IL-10 message, and underwent more apoptosis in response to anti-IgM than did nonaggressive B-1 clones. Taking these characteristics together, we have composed a comprehensive animal model system for human CLL that includes both the aged NZB mice for the early stage and the recipients of the in vitro B-1 line for the late stage or Richter's syndrome. This model system can be used to study, not only the ontogeny and genetic linkage of CLL, but also the regulatory factors involved in transformation and growth both in vivo and in vitro.

A cultured malignant B-1 line serves as a model for Richter's syndrome

Human chronic lymphocytic leukemia (CLL) is a malignancy of B-1 cells characterized by the accumulation of mature appearing, long lived, slow growing B-1 cells in peripheral blood. CLL occasionally evolves into an aggressive large cell lymphoma termed Richter's syndrome. NZB mice can be used to model the early stage of CLL because aged NZB mice can spontaneously develop slow growing malignant B-1 cell clones. The malignant NZB B-1 clones fail to grow in culture and are typically carried in vivo as passaged lines. During serial passage, an aggressive lymphoma developed as a result of a continued transformation of the original B-1 clone, similar to the development of Richter's syndrome. An in vitro cell line was established from the aggressive lymphoma, which was stromal dependent and could rapidly metastasize when passaged into recipient animals. Analysis of adhesion molecules did not reveal any consistent characteristics that could account for the metastatic potential of the Richter's-like cells. In addition, the aggressive in vitro line had the identical heavy chain sequence as the slow growing NZB malignant B-1 clones. The in vitro and in vivo aggressive B-1 cells had very high levels of IL-10 message, and underwent more apoptosis in response to anti-IgM than did nonaggressive B-1 clones. Taking these characteristics together, we have composed a comprehensive animal model system for human CLL that includes both the aged NZB mice for the early stage and the recipients of the in vitro B-1 line for the late stage or Richter's syndrome. This model system can be used to study, not only the ontogeny and genetic linkage of CLL, but also the regulatory factors involved in transformation and growth both in vivo and in vitro.

Correlative factors of left ventricular hypertrophy in end-stage renal disease

The correlative factors of left ventricular hypertrophy (LVH) in 287 end-stage renal disease (ESRD), admitted from 1983 to 1992, were analyzed. 52% of patients had LVH including 54% of patients on hemodialysis, 75% of patients with peritoneal dialysis and 38% of transplanted patients. Single factor analysis indicated that age, blood pressure, serum creatinine and BUN, hemoglobin, serum alkaline phosphatase, aortic valve disease and present DSRD therapy were related to LVH. Multiple logistic regression analysis indicated that the most important factors which independently related to LVH in all patients studied, were management of present ESRD treatment, age, hypertension and high serum alkaline phosphatase. In a subset of patients with severe LVH, high serum alkaline phosphatase level, high systolic blood pressure and age were the predictive factors. In patients on dialysis, the most important variable were age and high serum alkaline phosphatase. Hypertension was the sole predictor of LVH in the transplant group.

Apoptosis induction in CD5+(Ly1+) malignant B cells

Apoptosis, or programmed cell death, was studied in B-1 (CD5+ B) cells from NZB mice and their hybrids. NZB mice, as they age, develop clones of B-1 cells with the majority of the clones possessing extra chromosomes (hyperdiploid). These clones differ in growth characteristics, varying from a slow-growing non-invasive clonal expansion of B-1 cells, similar to chronic lymphocytic leukemias (CLL), to an aggressive fast-growing invasive malignancy, similar to Richter's syndrome. Apoptosis was induced in cultures of B-1 cells purified from peritoneal wash-out cells with either anti-immunoglobulin (anti-IgM) or lipopolysaccharide (LPS). The malignant hyperdiploid B-1 cells had increased apoptosis in response to these stimuli as determined by the presence of fragmented DNA. The amount of apoptosis was directly related to the aggressive nature of the B-1 cells. The increased apoptosis observed in malignant B-1 cells was also correlated with the state of activation of the cells. Malignant B-1 cells undergoing high levels of apoptosis had high spontaneous activation and IgM production. The supernatant levels of IgM in unstimulated cultures of aggressive malignant B-1 cells were the same as that stimulated with LPS, indicating that the malignant B-1 clones were maximally activated in vivo. In conclusion, hyperdiploid B-1 cells appear to have altered responses to stimuli that normally activate mature B cells. A signal for apoptosis rather than stimulation may result when malignant B-1 clones have their antigen receptors engaged. The increased apoptosis capability of malignant B-1 cells may be exploited as a therapeutic tool.

Probing actin incorporation into myofibrils using Asp11 and His73 actin mutants

We used a cell free system Bouché et al.: J. Cell Biol. 107:587-596, 1988] to study the incorporation of actin into myofibrils. We used alpha-skeletal muscle actin and actins with substitutions of either His73 [Solomon and Rubenstein: J. Biol.Chem. 262:11382, 1987], or Asp11 [Solomon et al.: J. Biol. Chem. 263:19662, 1988]. Actins were translated in reticulocyte lysate and incubated with myofibrils. The incorporated wild type actin could be cross-linked into dimers using N,N'-1,4-phenylenebismaleimide (PBM), indicating that the incorporated actin is actually inserted into the thin filaments of the myofibril. The His73 mutants incorporated to the same extent as wild type actin and was also cross-linked with PBM. Although some of the Asp11 mutants co-assembled with carrier actin, only 1-3% of the Asp11 mutant actins incorporated after 2 min and did not increase after 2 hr. Roughly 17% of wild type actin incorporated after 2 min and 31% after 2 hr. ATP increased the release of wild type actin from myofibrils, but did not increase the release of Asp11 mutants. We suggest that (1) the incorporation of wild type and His73 mutant actins was due to a physiological process whereas association of Asp11 mutants with myofibrils was non-specific, (2) the incorporation of wild type actin involved a rapid initial phase, followed by a slower phase, and (3) since some of the Asp11 mutants can co-assemble with wild type actin, the ability to self-assemble was not sufficient for incorporation into myofibrils. Thus, incorporation probably includes interaction between actin and a thin filament associated protein. We also showed that incorporation occurred at actin concentrations which would cause disassembly of F-actin. Since the myofibrils did not show large scale disassembly but incorporated actin, filament stability and monomer incorporation are likely to be mediated by actin associated proteins of the myofibril.