[Effects of fat emulsion on serum lipid, apo A I, apo B100, LCAT, KBR of postoperative patients with liver disorder]

Twenty post-operative patients with liver disorder were divided randomly into two groups. Ten of them received mean 0.82 g.kg-1.d-1 fat emulsion(42% of the total calorie), and the other ten received mean 1.72 g.kg-1.d-1 fat emulsion (52% of the total calorie) via vein during 5 post-operative days. Their serum lipid, apoA I, apoB100, ketone body ratio (KBR), fat clearance, LCAT and so on were investigted. The results suggest that it is safe for liver-disordered patients with slight or even moderate abnormality of liver function to receive mean 0.82 g.kg-1.d-1 and 1.72 g.kg-1.d-1 fat emulsion after operation and the use of mean 1.72 g.kg-1.d-1 fat emulsion will do no harm but good to liver function.

[Hepatectomy for hepatolithiasis treatment of 354 cases]

OBJECTIVE

To evaluate the effect of hepatectomy for hepatolithiasis.

METHOD

354 patients with hepatolithiasis underwent hepatectomy in the past 10 years. The results were analysed retrospectively, including clinical findings, distribution of stones, patterns of operation, postoperative complications, and residual stones. The clinical data of the patients before 1990 were compared with those thereafter.

RESULT

Left hepatolithiasis was the most common form (323 patients). Left lateral lobectomy and left hepatectomy were most commonly employed (91.2%). 166 of the patients underwent concurrent cholangiojejunostomy. 13.8% patients had residual stones, and postoperative complications occurred in 60 patients, including 4 deaths. Few patients were reoperated on and the incidence of residual stones was lower after 1990. 88% the patients showed excellent or good result.

CONCLUSION

Hepatectomy is a procedure for the management of hepatolithiasis, but still requires combined plasty of stenotic intrahepatic bile ducts and cholangiojejunostomy to reduce the incidence of residual stones and recurrence.

[Function analysis of regulative region of transforming gene Tx related to human nasopharyngeal carcinoma]

Tx gene is the DNA sequence with transforming activity which was cloned from the epithelial cell line (CNE2) of human nasopharyngeal carcinoma (NPC). In order to understand the role of Tx in carcinogenesis of NPC, the promoter function of potential promoter region in Tx2. 8 was detected using CAT reporter assay. The results showed that the region has no promoter function. It suggested that Tx2. 8 kb fragment homogenous to IGKC might be regulated by the specific mechanism of immunoglobulin gene.

Salt loading enhances rat renal TxA2/PGH2 receptor expression and TGF response to U-46,619

The tubuloglomerular feedback (TGF) response is potentiated by thromboxane A2 (TxA2) and/or prostaglandin endoperoxide (PGH2) acting on specific receptors. Infusion of the TxA2/PGH2 mimetic, U-46,619, into conscious rats leads to hypertension that is potentiated by a high-salt intake. Therefore, we tested the hypothesis that a high-salt intake enhances the expression of transcripts for TxA2/PGH2 receptors in the kidney and glomeruli and enhances the response of TGF to TxA2/PGH2 receptor stimulation. Groups of rats were accommodated to a low-salt (LS), normal salt (NS), or high-salt (HS) diet for 8-10 days. TxA2/PGH2 receptor mRNA was detected by reverse transcription-polymerase chain reaction in kidney cortex, isolated glomeruli, and abdominal aorta. TxA2/PGH2 mRNA abundance was significantly (P < 0.001) increased during intake of high-salt compared with low-salt diets in the kidney cortex (1.34 +/- 0.10 vs. 0.84 +/- 0.04 arbitrary units) and isolated outer cortical glomeruli (0.68 +/- 0.04 vs. 0.32 +/- 0.03 arbitrary units), but there was no effect of salt on TxA2/PGH2 receptor mRNA expression in the aorta. Maximal TGF responses were assessed from the increase in proximal stop flow pressure (an index of glomerular capillary pressure) during increases in loop of Henle perfusion with artificial tubular fluid from 0 to 40 nl/min. Compared with vehicle, the enhancement of maximal TGF with U-46,619 (10(-6) M) added to the perfusate was greater in rats adapted to high-salt than normal salt (HS: +9.6 +/- 1.1 vs. NS: +5.1 +/- 0.4 mmHg; P < 0.001) or low-salt (LS: +3.8 +/- 1.3 mmHg; P < 0.001) intakes. Responses to U-46,619 at each level of salt intake were blocked by > 70% by the TxA2/PGH2 receptor antagonist ifetroban. In contrast, enhancement of TGF by peritubular capillary perfusion of arginine vasopressin (AVP; 10(-7) M) was similar in high-salt and low-salt rats (HS: +1.5 +/- 0.6 vs. LS: +1.6 +/- 0.5 mmHg; not significant). We conclude that salt loading increases selectively the abundance of TxA2/PGH2 receptor transcripts in the kidney cortex and glomerulus, relative to the aorta, and enhances selectively TGF responses to TxA2/PGH2 receptor activation but not to AVP.

Oral health status and oral health behaviour of 12-year-old urban schoolchildren in the People's Republic of China

OBJECTIVE

To describe oral health status of urban Chinese children aged 12 years, to evaluate the pattern of oral health behaviour, and to assess the relative effect of socio-behavioural risk factors on dental caries experience.

DESIGN

A cross-sectional survey of 12-year-old children was conducted in the Hubei Province of China, including urban and periurban groups. The sampling was in accordance with the WHO procedures as applied in the second national survey of oral health. Data were collected by clinical examinations and use of self-administered questionnaires.

SETTING

The survey was initiated by the National Committee of Oral Health, China, in order to aid the planning and evaluation of school-based oral health care.

SUBJECTS

A sample of 698 children aged 12 years (96 per cent of original sample) participated in the survey; the sample was balanced by gender and urbanisation (urban/periurban).

OUTCOME MEASURES

The children were clinically examined according to the WHO basic methods and responded to standardised questionnaires on oral health behaviour, knowledge, and attitudes.

RESULTS

The mean DMFT of the children was 0.77 and DT constituted most of the caries index. About 65 per cent of the children had CPITN maximum score 2 (gingival bleeding and calculus). Only 40 per cent brushed their teeth at least twice a day and 46 per cent had seen a dentist within the past year. Variations by urbanisation were observed and the multiple linear regression of dental caries experience revealed that consumption of surgary foods, location and dental visits were the most important independent variables.

CONCLUSION

This study has shown that systematic oral health promotion programmes for children in China are urgently needed.

Patterns of connectivity in a Drosophila nerve

We investigated the spatial patterns of synaptic profiles in en passant synapses between the premotor axon of a peripherally synapsing interneuron (PAPSI) and a set of individually identifiable motoneuron axons in Drosophila melanogaster. These synaptic profiles are distributed as the axons travel parallel to each other in a bundle; the synapses begin as the axons leave the thoracic ganglion and continue peripherally for 45-65 microm. We found that the number of synaptic profiles per micron length of the motoneuron axons was greatest close to the ganglion; the cumulative distribution of profiles could be fitted to curves of the form f(x) = alpha(1 - e(-beta x)), where x = the distance from the thoracic ganglion, and alpha and beta are constants. The distribution of synaptic profiles was also examined in a mutant strain, Passover (Pas), known to affect connectivity in a pathway that includes the PAPSI. The synaptic profiles between the PAPSI and the motoneuron axons appeared ultrastructurally unremarkable in Pas. Also, the total number of synaptic profiles between the PAPSI and the motoneuron axons did not differ between Pas and wild type flies. However, the distribution of synaptic profiles among the individual motoneuron axons did differ significantly from wild type flies, as did the area of contiguity between the motoneuron axons and the PAPSI, which was much greater in Pas than in wild type flies.

Cisplatin pharmacokinetics in children with cancer

Cisplatin is an important drug in the treatment of a number of paediatric cancers yet, despite widespread use, there are only very limited data on the pharmacokinetics of the drug in children. Cisplatin pharmacokinetics were studied in 21 patients following a 24 h infusion of 50-120 mg/m2 cisplatin. Total and free platinum (Pt) levels in plasma and Pt in urine, were measured by atomic absorption spectrophotometry. Pharmacokinetic parameters were determined by non-compartmental and compartmental analyses. There was 3-fold interpatient variability in free drug exposure (area under the plasma concentration versus time curve--AUC) for a given surface area-based dose of cisplatin. The mean (+/- SD) pharmacokinetic parameters for free Pt were: AUC 0.47 +/- 0.13 mg/ml.min/100 mg/m2, Vdss 12.5 +/- 2.7 l/m2, t1/2 39 +/- 9 min, Ke 0.019 +/- 0.006 min-1, Clrenal 62 ml/min/m2, Cltotal 233 +/- 455 ml/min/m2, Cpss 0.31 +/- 0.09 microgram/ml. The total free Pt clearance was 1.5-5.8-fold higher (3.4 +/- 1.0) than the glomerular filtration rate (GFR). The renal clearance of cisplatin was not related to GFR and cisplatin was subject to only limited urinary excretion (27% administered dose 0-48 h), indicating that there are other important pathways of clearance beside renal elimination. Patient and treatment heterogeneity precluded the investigation of pharmacokinetic-pharmacodynamic relationships; however, the degree of interpatient pharmacokinetic variability observed suggests that body surface area-based dosing of cisplatin in children is not satisfactory.

[Mineralization of human dental pulp cells in continued culture]

The purpose of this study was to understand the mineralization of human dental pulp cells in vitro. Pulp cells were isolated from human normal permanent teeth and cultured in normal tissue-culture medium. With continued culture, pulp cells formed cell nodules after 12-15 days, but no cell nodules were found from human gingiva fibroblasts. Pulp cells showed high alkaline phosphatase activity and the nodules were strongly stained by Von Kossa. Furthermore, the nodules showed high level of calcium and phosphorus by Energy-dispersive X-ray analysis and pulp cells had similar ultrastrusture with odontoblasts under TEM. The continued culture of pulp cells provides a useful system for studying differentiation and calcification of pulp tissue.

[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.