Effects of geometric isomerism and ligand substitution in bifunctional dinuclear platinum complexes on binding properties and conformational changes in DNA

The DNA binding profile of a series of dinuclear platinum complexes [{trans-PtCl-(L)2}2H2N(CH2)nNH2]2+ (L = NH3 or py; 1,1/t,t/NH3 and 1,1/t,t/py, respectively) and [{cis-PtCl-(NH3)2H2N(CH2)nNH2]2+ (1,1/c,c/NH3) was examined to compare the effects of geometrical isomerism and the presence of ligands other than NH3 in the coordination sphere. Steric effects, because of the geometry of the leaving groups cis to the diamine bridge or the presence of planar pyridine ligands, result in diminished binding to calf thymus DNA for these isomers. In contrast, the pyridine derivative shows a distinct binding preference for poly(dG-dC).poly(dG-dC) in comparison to both NH3 isomers. Both NH3 complexes induced the B-->Z transition in poly(dG-dC).poly(dG-dC), but the presence of a pyridine ligand stabilized the B conformation. The bifunctional binding of the NH3 isomers results in unwinding of supercoiled pUC19 plasmid DNA equivalent to cis-DDP, while the unwinding of the pyridine derivative is approximately twice that of the mononuclear trans-[PtCl2(py)2]. DNA-DNA interstrand cross-linking is very efficient for all three agents, but sequencing studies indicated that only the 1,1/t,t/NH3 derivative is capable of forming a (Pt,Pt) intrastrand cross-link to the adjacent guanines of a d(GpG) sequence. The effects on DNA caused by bifunctional binding of dinuclear complexes are compared with those from the mononuclear [PtCl2(NH3)2] isomers. The results are discussed with respect to the antitumor activity of the dinuclear series.

Preclinical toxicity of liposome-incorporated annamycin: selective bone marrow toxicity with lack of cardiotoxicity

Annamycin (Ann) is a new lipophilic anthracycline antibiotic with a marked ability to circumvent typical multidrug resistance both in vitro and in vivo. Because of its high affinity for lipid membranes and very low solubility in water, Ann has been prepared in a submicron liposome formulation (L-Ann) that is currently being investigated in a Phase I clinical study. We studied the preclinical toxicity of L-Ann in mice and beagle dogs and compared it with that of free Ann in suspension and the parent compound doxorubicin (Dox). In mice, free Ann was about twice as toxic as Dox (LD50 after a single i.v. bolus administration, 8.8 versus 19.9 mg/kg; P < 0.01). The liposomal carrier reduced Ann toxicity by 2-fold (LD50, 15.74 mg/kg for L-Ann versus 8.8 mg/kg for free Ann; P < 0.01). Granulocytopenia was the main toxicity of Ann, either free or liposome incorporated, and was much more profound than with an equitoxic dose of Dox as assessed by blood counts and pathological studies. In chronic mouse studies, L-Ann was remarkably less cardiotoxic than Dox. Cumulative toxicity with the weekly administration of a given fraction of the subacute LD10 was markedly higher with Dox than with L-Ann as assessed by body weight and mortality studies. L-Ann also had less vesicant toxicity than Dox after intradermal administration in mice. Beagle dogs tolerated the mouse-equivalent LD10 dose of L-Ann (1.4 mg/kg) with no side effects, changes in the hematological and biochemical blood parameters, or pathological changes. Our results indicate that: (a) L-Ann is more selectively myelotoxic than Dox and is noncardiotoxic; (b) the liposome carrier plays a major role in the favorable toxicity profile of L-Ann; and (c) the standard one-tenth of the LD10 should be a safe starting dose for Phase I clinical trials with L-Ann in humans.

Interaction of the UvrABC nuclease system with a DNA duplex containing a single stereoisomer of dG-(+)- or dG-(-)-anti-BPDE

Oligonucleotides containing site-specifically-modified N2-guanine (+)-trans-, (-)-trans-, (+)-cis-, and (-)-cis-BPDE adducts were ligated into 50-base-pair DNA fragments. These substrates were used in reactions with the Escherichia coli UvrABC nuclease system. The interaction of the UvrA2 and UvrA2B complexes with these four stereoisomers was probed using DNase I footprinting and gel mobility shift assays. DNase I digestion of substrates containing each stereoisomer of BPDE displayed a unique pattern which was consistent with the known structure of these DNA adducts. UvrA and UvrA2B appeared to interact very similarly with all four substrates. Binding of UvrA2 to these substrates produced a 33-bp footprint, and the UvrB--DNA complex resulted in footprint of 24 bp. The UvrABC nuclease system produced bimodal incisions at the eighth phosphate 5' and the fifth, sixth, or seventh phosphate 3' to the modified guanine. The variation of the 3' incision site was linked to the stereochemistry and orientation of the BPDE adduct. For example, the 3' incision of the 50-bp duplex containing (-)-trans-BPDE-N2-guanine was inhibited at the fifth phosphate. UvrABC nuclease incision kinetics revealed a hierarchy of specificity. The intercalative cis isomers were incised more efficiently than the corresponding trans isomers which lie in the minor groove. The (+) enantiomers were incised more efficiently than the (-) form for both cis and trans isomers. These observations reveal that UvrABC nuclease recognition and incision are directly influenced by the conformation of the DNA adduct.

Nd: YAG laser lysis of the fibrinous membrane and remnant substance on the anterior surface of intraocular lens

PURPOSE

To determine the effects of Nd: YAG laser to disrupt the fibrinous membrane and remnant substance on the anterior surface of intraocular lens.

METHODS

Nd: YAG laser was applied on 23 cases of fibrinous membrane formation and 8 cases of remnant substance on the anterior surface of intraocular lenses (IOL) which had not responded well to steroid therapy. Eighteen cases were male and 13 female. The mean age was 49.7 years (range, 5 approximately 78 years). The interval between IOL implantation and laser therapy was 0.5 approximately 30 months in the fibrinous membrane cases and 3 approximately 10 days in the remnant substance cases. The energy applied was 0.8 approximately 3.0 mJ/exp. with 2 approximately 112 exposures. Mean follow-up period was 3.6 months.

RESULTS

Complications during therapy included only 2 cases of slight iris bleeding. Visual acuity after therapy was improved 1 line in 16 cases, 2 lines in 11 cases, 3 lines in 1 case, 4 lines in 1 case and 5 lines in 2 cases. No post-therapy complication was found.

CONCLUSIONS

Nd: YAG laser lysis is an effective alternative to remove the fibrinous membrane and remnant substances on the anterior surface of IOL.

Primary posterior chamber intraocular lens implantation in traumatic cataract with posterior capsule breaks

BACKGROUND

In patients with incomplete posterior capsule support, posterior chamber intraocular lenses (PC-IOLs) were implanted with both haptics transscleral fixation. This causes more damage to the eye and may result in more complications. In patients with small posterior breaks, non-fixation or single haptic fixation may be adequate.

METHODS

Thirty-two consecutive patients of traumatic cataract with posterior capsule breaks caused by penetrating eye trauma were retrospected. Posterior chamber intraocular lenses were implanted in all these patients with three techniques, ie, without fixation, with single haptic fixation and with both haptics fixation. The selection of the technique was based on the position and size of the posterior capsule. The follow-up period was 21 days to 28 months (mean, 15.2 months).

RESULTS

Intra-operative problems included ciliary body bleeding (two patients, 6.25%) and enlargement of posterior capsule breaks (2 patients, 6.25%). Postoperative visual acuity was 0.5 or better (corrected) in 28 case (87.5%) and 0.1-0.4 in four patients (12.5%). Postoperative complications included hyphema (6 eyes, 18.8%), transient intraocular pressure elevation (6 eyes, 18.8%), transient hypotention (7 eyes, 21.8%). Postoperative IOL position were good except one case of IOL tilt. No pupillary capture or endophthalmitis was found.

CONCLUSIONS

Not all PC-IOLs have to be fixed by two haptics. In patients with small posterior capsule breaks, PC-IOL may not be fixed or fixed by only one haptics.

Angiotensin II partly mediates mechanical stress-induced cardiac hypertrophy

We have previously shown that mechanical stress induces activation of protein kinases and increases in specific gene expression and protein synthesis in cardiac myocytes, all of which are similar to those evoked by humoral factors such as growth factors and hormones. Many lines of evidence have suggested that angiotensin II (Ang II) plays a vital role in cardiac hypertrophy, and it has been reported that secretion of Ang II from cultured cardiac myocytes was induced by mechanical stretch. To examine the role of Ang II in mechanical stress-induced cardiac hypertrophy, we stretched neonatal rat cardiac myocytes in the absence or presence of the Ang II receptor antagonists saralasin (an antagonist of both type 1 and type 2 receptors), CV-11974 (a type 1 receptor-specific antagonist), and PD123319 (a type 2 receptor-specific antagonist). Stretching cardiac myocytes by 20% using deformable silicone dishes rapidly increased the activities of mitogen-activated protein (MAP) kinase kinase activators and MAP kinases. Both saralasin and CV-11974 partially inhibited the stretch-induced increases in the activities of both kinases, whereas PD123319 showed no inhibitory effects. Stretching cardiac myocytes increased amino acid incorporation, which was also inhibited by approximately 70% with the pretreatment by saralasin or CV-11974. When the culture medium conditioned by stretching cardiocytes was transferred to nonstretched cardiac myocytes, the increase in MAP kinase activity was observed, and this increase was completely suppressed by saralasin or CV-11974. These results suggest that Ang II plays an important role in mechanical stress-induced cardiac hypertrophy and that there are also other (possibly nonsecretory) factors to induce hypertrophic responses.

Mechanical stress activates protein kinase cascade of phosphorylation in neonatal rat cardiac myocytes

We have previously shown that stretching cardiac myocytes evokes activation of protein kinase C (PKC), mitogen-activated protein kinases (MAPKs), and 90-kD ribosomal S6 kinase (p90rsk). To clarify the signal transduction pathways from external mechanical stress to nuclear gene expression in stretch-induced cardiac hypertrophy, we have elucidated protein kinase cascade of phosphorylation by examining the time course of activation of MAP kinase kinase kinases (MAPKKKs), MAP kinase kinase (MAPKK), MAPKs, and p90rsk in neonatal rat cardiac myocytes. Mechanical stretch transiently increased the activity of MAPKKKs. An increase in MAPKKKs activity was first detected at 1 min and maximal activation was observed at 2 min after stretch. The activity of MAPKK was increased by stretch from 1-2 min, with a peak at 5 min after stretch. In addition, MAPKs and p90rsk were maximally activated at 8 min and at 10 approximately 30 min after stretch, respectively. Raf-1 kinase (Raf-1) and (MAPK/extracellular signal-regulated kinase) kinase kinase (MEKK), both of which have MAPKKK activity, were also activated by stretching cardiac myocytes for 2 min. The angiotensin II receptor antagonist partially suppressed activation of Raf-1 and MAPKs by stretch. The stretch-induced hypertrophic responses such as activation of Raf-1 and MAPKs and an increase in amino acid uptake was partially dependent on PKC, while a PKC inhibitor completely abolished MAPK activation by angiotensin II. These results suggest that mechanical stress activates the protein kinase cascade of phosphorylation in cardiac myocytes in the order of Raf-1 and MEKK, MAPKK, MAPKs and p90rsk, and that angiotensin II, which may be secreted from stretched myocytes, may be partly involved in stretch-induced hypertrophic responses by activating PKC.

Comparison of four methods to generate immunoreactive fragments of a murine monoclonal antibody OC859 against human ovarian epithelial cancer antigen

In the present study, four different proteases (pepsin, papain, bromelain and ficin) were screened with a murine monoclonal antibody OC859, in order to verify whether different digestion procedures could improve yield and stability of the F(ab')2 or Fab fragments. The yields of F(ab')2 or Fab fragments from digestion with pepsin, papain, bromelain and ficin were respectively 20.3 +/- 2.0%, 50.5 +/- 5.0%, 74.4 +/- 2.7% and 82.8 +/- 10.2% of the theoretical maximum. Immunoreactivity in a noncompetitive solid-phase radioimmunoassay (SPRIA) of the fragments generated by the four proteases were respectively 10 +/- 5%, 36 +/- 5%, 60 +/- 6% and 75 +/- 6% of the intact OC859 IgG. These results suggested that the fragmentation of OC859 with ficin gave a higher yield of superior immunoreactive fragments.

EFIA/YB-1 is a component of cardiac HF-1A binding activity and positively regulates transcription of the myosin light-chain 2v gene

Transient assays in cultured ventricular muscle cells and studies in transgenic mice have identified two adjacent regulatory elements (HF-1a and HF-1b/MEF-2) as required to maintain ventricular chamber-specific expression of the myosin light-chain 2v (MLC-2v) gene. A rat neonatal heart cDNA library was screened with an HF-1a binding site, resulting in the isolation of EFIA, the rat homolog of human YB-1. Purified recombinant EFIA/YB-1 protein binds to the HF-1a site in a sequence-specific manner and contacts a subset of the HF-1a contact points made by the cardiac nuclear factor(s). The HF-1a sequence contains AGTGG, which is highly homologous to the inverted CCAAT core of the EFIA/YB-1 binding sites and is found to be essential for binding of the recombinant EFIA/YB-1. Antiserum against Xenopus YB-3 (100% identical in the DNA binding domain and 89% identical in overall amino acid sequence to rat EFIA) can specifically abolish a component of the endogenous HF-1a complex in the rat cardiac myocyte nuclear extracts. In cotransfection assays, EFIA/YB-1 increased 250-bp MLC-2v promoter activity by 3.4-fold specifically in the cardiac cell context and in an HF-1a site-dependent manner. EFIA/YB-1 complexes with an unknown protein in cardiac myocyte nuclear extracts to form the endogenous HF-1a binding activity. Immunocoprecipitation revealed that EFIA/YB-1 has a major associated protein of approximately 30 kDa (p30) in cardiac muscle cells. This study suggests that EFIA/YB-1, together with the partner p30, binds to the HF-1a site and, in conjunction with HF-1b/MEF-2, mediates ventricular chamber-specific expression of the MLC-2v gene.

Effect of vesicle size and lipid composition on the in vivo tumor selectivity and toxicity of the non-cross-resistant anthracycline annamycin incorporated in liposomes

Annamycin (Ann) is a non-cross-resistant lipophilic anthracycline antiobiotic optimally suited for liposome delivery. We studied how vesicle size and presence of phospholipids with a high phase transition temperature and monosialoganglioside (GM I) in the liposome bilayers affect the pharmacokinetics, tumor selectivity and toxicity of Ann. Entrapment of Ann in multilamellar vesicles (L-Ann) resulted in a 20% lower heart AUC and a 30-40% higher tumor and liver AUC. Reduction of the liposome size from 1.6 to 0.03 microns increased Ann plasma circulation time and tumor AUC by 2-fold, enhanced Ann tumor selectivity and decreased Ann subacute toxicity by 2-fold. The presence of phospholipids with a high phase transition temperature and GMI in the liposome bilayers further prolonged Ann plasma circulation time by 2- to 4-fold, did not increase Ann tumor AUC and moderately increased Ann subacute toxicity. The anti-tumor activity of Ann correlated with the tumor AUC achieved with each particular formulation. Our results strongly suggest that vesicle size may be an important determinant of the therapeutic index of liposomal Ann, but they fail to demonstrate a beneficial tumor-targeting effect of liposomes composed of GMI and phospholipids with a high phase transition temperature, as has been reported for the hydrophilic parent compound doxorubicin.

Cyanide inhibition of porcine kidney diamine oxidase and bovine plasma amine oxidase: evidence for multiple interaction sites

The interactions of cyanide and phenylhydrazine with porcine kidney diamine oxidase (PKDAO) and bovine plasma amine oxidase (BPAO) (EC 1.4.3.6) have been investigated. Cyanide displays mixed noncompetitive inhibition against amine substrates and also against O2. EPR spectroscopy shows that cyanide binds to an equatorial site on Cu(II) and can be displaced by chloride, which is not an inhibitor, without recovery of activity, indicating that Cu(II)-bound cyanide is not inhibitory. 14CN-. studies have shown that one cyanide in PKDAO and two in BPAO are covalently and irreversibly bound per enzyme dimer at an unknown site, even under conditions where cyanide is not bound to Cu(II). These cyanides have no effect on activity or on binding of phenylhydrazine to the enzymes. Cyanide also binds reversibly to the organic cofactor in both enzymes, presumably as a cyanohydrin, leading to the observed mixed noncompetitive inhibition against substrate. In both enzymes, two phenylhydrazines react per enzyme dimer. The kinetics of phenylhydrazine titration are affected by cyanide, which indicates that phenylhydrazine and cyanide react at the same carbonyl group in the enzymes. The results suggest that inhibition of amine oxidases by cyanide is through a carbonyl reagent and a Cu(I) ligand rather than through a Cu(II) ligand.

Partial circumvention of multi-drug resistance by annamycin is associated with comparable inhibition of DNA synthesis in the nuclear matrix of sensitive and resistant cells

We studied the subcellular and subnuclear distributions of the partially cross-resistant anthracycline Annamycin (Ann) in KB-3-1 and multi-drug resistant KB-VI cells. Subcellular drug localization was assessed qualitatively by fluorescence microscopy and quantitatively by cell fractionation and fluorescence measurements. Doxorubicin (Dox) localized predominantly in the nucleus in KB-3-1 cells and in the membranes in KB-VI cells. In contrast, the subcellular distribution of Ann was identical in both cell lines, with preferential drug localization in the perinuclear region, Golgi apparatus, endoplasmic reticulum and endosomes. Dox rate of efflux from the nucleus was negligible in KB-3-1 cells but markedly enhanced in KB-VI cells, whereas Ann was lost at a similar rate from the nucleus in both cell lines. In KB-3-1 cells Dox levels in the nuclear non-matrix were about 2-fold higher than those of Ann, while in the matrix the inverse relationship was observed. In spite of these differences, Dox and Ann had a similar inhibitory effect on new DNA synthesis in the nuclear matrix and non-matrix of KB-3-1 cells. Dox levels were reduced by 10-fold in the nuclear non-matrix and 2-fold in the matrix in KB-VI cells compared with KB-3-1 cells, whereas Ann levels were reduced by about 2- to 3-fold in the non-matrix and were unchanged in the matrix. In correlation with these findings, Dox did not cause inhibition of new DNA synthesis in either nuclear fraction in KB-VI cells, whereas inhibition of new DNA synthesis in the matrix by Ann was similar in both cell lines. Our results indicate that Ann's partial circumvention of multi-drug resistance is associated with its ability to cause comparable new DNA synthesis inhibition in the nuclear matrix of sensitive and resistant cells.

Sequence specificity of DNA-DNA interstrand cross-link formation by cisplatin and dinuclear platinum complexes

The sequence specificity of interstrand cross-links induced in DNA by mononuclear and dinuclear platinum complexes in a 49-base-pair DNA duplex has been determined directly. This new assay takes advantage of the fact that 3'-->5' exonuclease digestion of randomly platinated DNA produces a pool of fragments of different lengths. This treatment allows identification of the spectrum of adducts impeding the exonuclease scission. Interstrand cross-linked adducts produce fragments that may remain complementary in the proximity of the binding site. As a result, these fragments may act as primer templates for extension upon subsequent treatment with a DNA polymerase. This extension increases the size of the oligonucleotide fragments, which may be evidenced by a more slowly migrating band on a sequencing gel. Concomitantly, the original band corresponding to the digested cross-link decreases in intensity. Therefore, comparison of a sequencing gel after digestion only and after the "digestion-extension" treatment should show the disappearance, or diminished band intensity, of only those fragments with interstrand cross-links. This approach was applied to the analysis of DNA interstrand cross-links formed by cis-[PtCl2(NH3)2] (cis-DDP) and [(trans-PtCl(NH3)2)2H2N(CH2)4NH2]Cl2. Cis-DDP was confirmed to form interstrand cross-links at d(GC) sequences but, interestingly, interstrand cross-links predominated in a sequence GCGG, with possible 1,3-intrastrand but no 1,2-intrastrand cross-links forming. The dinuclear compound formed 1,2, 1,3, and 1,4 DNA interstrand cross-links between guanines on opposite strands. In 1,3 and 1,4 cross-links, the guanines are separated by one and two base pairs, respectively, whereas a 1,2 cross-link is formed from guanines on neighboring base pairs.(ABSTRACT TRUNCATED AT 250 WORDS)

Antitumor activity of free and liposome-entrapped annamycin, a lipophilic anthracycline antibiotic with non-cross-resistance properties

The lipophilic anthracycline antibiotic annamycin (Ann) was entrapped in liposomes of different size [median diameter: 1.64 microns, multilamellar liposomal Ann (L-Ann); 0.030 micron, small unilamellar Ann (S-Ann)] with > 90% entrapment efficiency and tested in vitro against four pairs of sensitive and multidrug-resistant (MDR) tumor cell lines and in vivo by the i.v. route in five tumor models: advanced s.c. B16 melanoma; s.c. M5076 reticulosarcoma; lung metastases of Lewis lung carcinoma; and s.c. KB and KB-V1 xenografts in nude mice. Predetermined optimal doses of the different formulations were used and the results were compared with doxorubicin (Dox). In vitro, Ann, either in suspension in 10% dimethyl sulfoxide (F-Ann) (1 mg/ml) or entrapped in liposomes, was able to partially overcome resistance in all four pairs of sensitive and MDR KB, 8226, P388, and CEM cell lines (resistance indexes 63, 269, 333, and 356 for Dox versus 4, 5, 19, and 8.7 for L-Ann, respectively). In vivo, both F-Ann and liposome-entrapped Ann were slightly more effective than Dox in inhibiting the growth of advanced s.c. B16 melanoma tumors. L-Ann was markedly more effective than Dox and moderately more effective than F-Ann in prolonging the life span of animals bearing s.c. M5076 and lung metastases of Lewis lung carcinoma tumors. All drugs were equally effective at optimal doses in delaying the growth of s.c. KB xenografts, whereas all Ann formulations were markedly more effective than Dox in delaying the growth of s.c. KB-V1 (MDR) xenografts. In all in vivo experiments, S-Ann was consistently more effective than L-Ann and L-Ann was more effective than F-Ann. These results indicate that (a) Ann is more effective than Dox by the i.v. route against several tumor models and that MDR tumors are partially not cross-resistant to Ann both in vitro and in vivo, (b) liposomes enhance the in vivo antitumor properties of Ann, and (c) small liposomes are more effective than large liposomes in enhancing Ann antitumor activity.

Cellular pharmacology of the partially non-cross-resistant anthracycline annamycin entrapped in liposomes in KB and KB-V1 cells

The in vitro cytotoxicity, cellular pharmacology, and DNA lesions induced by the lipophilic anthracycline annamycin (Ann) were studied in KB and KB-V1 (multidrug-resistant) cells. Ann was tested in suspension in saline and 10% dimethylsulfoxide (DMSO: final concentration, 0.05%-0.5%) or entrapped in multilamellar liposomes (median size, 1.57 microns). Doxorubicin (Dox) was about twice as cytotoxic as Ann or liposome-entrapped Ann (L-Ann) against KB cells. Both Ann and L-Ann displayed a partial lack of cross-resistance with Dox (resistance indices: > 60 for Dox, 4.7 for Ann, 4.0 for L-Ann). Accumulation of Ann in KB and KB-V1 cells was consistently about 2-3 and 10-20 times higher, respectively, than that of Dox. Cellular retention of Ann in KB and KB-V1 cells was about 2 and 30 times higher, respectively, than that of Dox as a result of the different efflux patterns of the two drugs: Dox was not effluxed from KB cells but was significantly effluxed from KB-V1 cells (66% at 1 h, whereas Ann efflux was similar in both cell lines (about 50% at 1 h). Dox retention in KB-V1 cells was increased by a factor of 2 in the presence of verapamil or cyclosporine A, but Ann retention was not. In addition, accumulation of Dox in KB-V1 cells was enhanced by the metabolic inhibitor deoxyglucose/azide and the membrane carboxylic ionophore monensin, whereas accumulation of Ann was not affected by either agent. All these findings indicate significant differences in the cellular transmembrane transport systems between Dox and Ann and suggest that Ann efflux is not mediated by P-glycoprotein. Liposome entrapment reduced by a factor of 1.3-2.0 the cellular accumulation of Ann without affecting its cytotoxicity. As compared with Dox, both Ann and L-Ann induced 3 times more DNA double- and single-strand breaks in KB cells. In KB-V1 cells, Dox did not induce DNA damage, whereas the extent of DNA breaks induced by both Ann and L-Ann was similar to that induced by Dox in KB cells. Our results indicate (1) that the lack of cross-resistance between Ann and Dox is associated with a markedly enhanced accumulation and retention of Ann in KB-V1 cells and (2) that the type of liposomes used does not significantly affect the cellular effects of Ann.

Quantitative analysis of the lipophilic doxorubicin analogue annamycin in plasma and tissue samples by reversed-phase chromatography

A rapid and sensitive HPLC method was developed to detect and quantitate the lipophilic doxorubicin analogue annamycin (Ann) and its metabolites in biological samples. Reversed-phase chromatography coupled with fluorescence detection was used. The emission and excitation wavelengths of the fluorescent detector were set at 550 and 472 nm, respectively. The optimal mobile phase was acetonitrile:methanol:water at a 115:95:90 ratio (v/v/v). The lower limit of detection was 0.35 ng of Ann (7 ng/mL). The retention times of 4-demethoxyadriamycinone (Anone) and Ann were 2.6 and 4.3 min, respectively, and their resolution was 1.3. The precision of the determination of Ann and Anone were 0.5 +/- 0.3 and 0.8 +/- 0.7%, respectively. Ann dissolved in methanol was stable under the determination conditions. With chloroform, 60-90% of Ann was extracted from biological samples. Apart from Anone, two Ann metabolites (retention times 3.4 and 6.0 min) were detected in plasma and tissues from C57BL/6 mice bearing subcutaneous B16 tumors 6 h after intravenous administration of a 5-mg/kg suspension of Ann. No peaks were detected in blank tissues and plasma.

Ligand effects on platinum binding to DNA. A comparison of DNA binding properties for cis- and trans-[PtCl2(amine)2] (amine = NH3, pyridine)

The DNA binding properties of cis- and trans-[PtCl2(pyridine)2] have been examined and compared with their NH3 analogs, cis- and trans-DDP. The presence of a planar ligand reduces the rates of DNA binding but does not greatly affect the overall conformation of CT DNA, as measured by circular dichroism spectroscopy. The sequence specificity of trans-[PtCl2(py)2] includes alternating purine-pyrimidine sequences. The sequence specificity is further different between the two pyridine isomers, and the steric effects of two cis-pyridine groups are demonstrated by the appearance of relatively few binding sites in the 49-bp duplex. The effects of the pyridine ligand are further manifested by a greatly enhanced DNA-DNA interstrand cross-linking efficiency for the trans isomer, with a cross-link per adduct frequency of between 0.14 and 0.23, depending on the rb of the sample. The unwinding of closed circular pUC19 DNA by trans-[PtCl2(pyridine)2] is also more efficient than that by either DDP isomer, with an unwinding angle calculated at phi = 17 degrees (compare cis-DDP with phi = 13 degrees and trans-DDP with phi = 9-10 degrees). In contrast, little unwinding is induced by cis-[PtCl2(pyridine)2], with phi = 4 degrees. These results in particular invert the standard cis/trans structure-activity relationships observed previously for [PtCl2(NH3)2]. The results are discussed with respect to the previously demonstrated effect of activation of the trans-platinum geometry using sterically hindered ligands.

Enhanced therapeutic effect against liver W256 carcinosarcoma with temperature-sensitive liposomal adriamycin administered into the hepatic artery

The antitumor activity of Adriamycin encapsulated in temperature-sensitive liposomes combined with local hyperthermia (HT) was tested in rats bearing well-developed liver W256 carcinosarcoma tumors. Two h after rats received Adriamycin encapsulated in temperature-sensitive liposomes via either the hepatic artery (i.a.) or the femoral vein (i.v.) or free Adriamycin i.a., liver HT was applied at 42 degrees C for 6 min. In animals treated with liposomal Adriamycin i.a., HT resulted in a 38% reduction in the tumor volume ratio and a 2.2-fold increase in the life span of the animals. In animals treated with liposomal Adriamycin i.v. or free Adriamycin i.a., HT did not alter the tumor volume ratio or life span of the animals. Administration i.a. of liposomal Adriamycin markedly increased the tumor drug levels (4-14-fold), reduced the systemic distribution of the drug, and slowed the drug decrease from both the tumor and liver compared with animals treated i.v.. Liver HT in animals treated with liposomal Adriamycin i.a. further increased tumor drug levels by 1.5-2.6-fold, further slowed the drug decrease from the tumor, and resulted in a dissociation of the parallel decrease of drug and lipid from the tumor. This latter effect was not observed in the other groups. These pharmacological findings combined with the lack of beneficial effect from HT in animals treated with free Adriamycin i.a. or liposomal Adriamycin i.v. suggest that i.a. administration of Adriamycin encapsulated in temperature-sensitive liposomes results in a significant retention of intact liposomes in the tumor vasculature that are able to release the encapsulated drug into the tumor cell compartment upon raising the temperature to the phase transition level.

Near-infrared spectrophotometric monitoring of stroke-related changes in the protein and lipid composition of whole gerbil brains

Strokes are a critical problem in the U.S. that affect more than 500,000 people annually. Research into the causes of stroke and testing of drug therapies to reduce ischemic and postischemic damage to the brain is frustrated by an inability to continuously follow the physical and chemical events that occur during ischemia and reperfusion in vivo. Near-IR spectrometry is used in this paper to observe stroke-induced changes in the lipids and proteins of whole brain samples and in intact subjects. The examination of whole brains is made possible by a combination of hardware and software techniques designed to make the sample presentation to the spectrometer more reproducible. Near-IR spectrophotometry of brain tissue discriminates between adult (3-4 months of age) and aged (18-20 months of age) brains as well as between brains exposed to 5- and 10-min ischemia. The near-IR analytical method has many applications in aging and stroke research, including the noninvasive determination of age from brain spectra obtained transcranially, simultaneous multicomponent analysis of lipids and proteins, and quantification of edema.

Organ distribution and antitumor activity of free and liposomal doxorubicin injected into the hepatic artery

The plasma levels, organ distribution, and in vivo antitumor activity of free and liposomal doxorubicin injected into the hepatic artery of rats bearing W256 liver tumors were studied. The administration of liposomal doxorubicin resulted in liver-tumor and liver-parenchyma doxorubicin areas under the curve (AUCs) that were 4.7- and 3.8-fold, respectively, those obtained after the administration of free doxorubicin. Spleen and plasma AUCs were also increased by 2.8 and 2.5 times, respectively, following administration of the liposomal form. In contrast, liposomal doxorubicin did not affect heart AUCs; peak doxorubicin levels in heart tissue were three times lower in animals treated with liposomal doxorubicin. Following treatment with the liposomal form, the cumulative urinary excretion of doxorubicin at 8 h was 38 times lower. In good correlation with these findings, liposomal doxorubicin (2.35 mg/kg on day 7) was more effective than free doxorubicin against liver W256 tumors as measured by tumor-growth inhibition at 5 days after treatment (16% for liposomal doxorubicin versus -53.7% for free doxorubicin, P < 0.05) and increased life span (ILS; 108% for liposomal doxorubicin versus 27% for free doxorubicin, P < 0.05). These results demonstrate that as compared with free doxorubicin, the administration of liposomal doxorubicin into the hepatic artery results in higher drug levels in the liver tumor and enhanced antitumor activity while maintaining the cardioprotective effect of the liposome carrier as suggested by the decreased peak drug levels measured in the heart tissue.

Organ distribution and tumor uptake of annamycin, a new anthracycline derivative with high affinity for lipid membranes, entrapped in multilamellar vesicles

Annamycin (Ann) is a lipophilic, non-cross resistant anthracycline antibiotic that is easily amenable to formulation in a wide variety of liposomal carriers. We studied the organ distribution and tumor uptake of Ann entrapped in multilamellar vesicles (L-Ann), free annamycin (F-Ann), and doxorubicin (DOX) in C57BL/6 mice bearing advanced subcutaneous B16 melanoma tumors. L-Ann was composed of DMPC: DMPG: Ann at a molar ratio of 7:3:0.7. Mean particle size was 1.88 +/- 0.89 microns, and the entrapment efficiency was 93.08% +/- 2.96%. F-Ann was prepared as a suspension (particle size < or = 0.2 microns) in 10% DMSO. Drug levels were measured by fluorescence spectrometry after extraction with chloroform. The extraction ratio ranged between 60% and 90% for both drugs in most tissues. Compared with those of DOX, organ AUCs of L-Ann were threefold higher in plasma and brain, twofold higher in liver and kidney, sixfold higher in lung, ninefold higher in spleen, and tenfold higher in B16 tumors. Compared with F-Ann, organ AUCs of L-Ann were twofold higher in plasma, liver, and B16 tumors and were twofold lower in brain. Heart AUCs were similar with all three drugs. Higher tumor uptake was associated with a faster penetration and more prolonged retention of Ann in tumor tissue compared with those of DOX. The results obtained indicate significant differences in organ distribution between L-Ann and DOX as a result of the higher affinity of Ann for lipid membranes and the use of the liposomes as a delivery system. The potential clinical relevance of the increased uptake of L-Ann in B16 tumors, lung, and brain is being investigated.

Geometry for contouring by electronic speckle pattern interferometry based on shifting illumination beams

When the method of contouring an object surface by electronic speckle pattern interferometry is based on shifting the illumination beams, the shifted phase of the interference speckle pattern has a new relationship with the depth of the test surface. Therefore the contour interval as well as the fringe sensitivity of this method has new forms. The geometry of such a situation, which differs from that of either the method of two-wavelength contouring or the method of contouring by tilting the test object is presented. The requirements on the experimental conditions for this method are also presented. Experimental results are in agreement with these analyses.

Contouring by electronic speckle pattern interferometry with quadruple-beam illumination

We present a new arrangement for contouring by electronic speckle pattern interferometry with four illumination beams, thereby making it unnecessary to move anything during the.

[High performance liquid chromatographic determination of hydroxyphenytoin in human urine]

A high-performance liquid chromatographic method for the determination of p-hydroxyphenytoin (p-HDPH) in human urine was reported. Following acid hydrolysis of urine sample at 90 degrees C for 1 h, an internal standard, nitrophenol, was added. The sample was extracted with n-hexane-ethyl acetate (50:50), and organic layer was evaporated. The residue was dissolved in methanol and chromatographed on an Ultrasphere-ODS column, using a mobile phase of phosphate buffer (0.03 mol/L, pH 6.0): methanol (65:35) at a flow rate of 0.8 ml/min. The eluent was monitored at 240 nm. The standard curve was linear within the range 5.0-200 micrograms/ml (r = 0.9998). Analytical recovery rates were 102.8 +/- 7.3% (p-HDPH 9.70 micrograms/ml, n = 5) and 104.9 +/- 6.4% (p-HDPH 54.70 micrograms/ml, n = 5). The cumulative recovery of p-HDPH in 0-12 h volunteers' urine samples accounted for 20% of the oral dose of 100 mg phenytoin sodium.

Targeting liver tumors by administering liposomal doxorubicin into the hepatic artery

The plasma levels, organ distribution, and in vivo anti-tumor activity of liposomal doxorubicin administered i.v. or i.a. (hepatic) in rats bearing W256 liver tumors were studied. I.a. administration of liposomal doxorubicin resulted in 4-fold and 1.3-fold higher liver tumor and liver parenchyma doxorubicin levels, respectively, than i.v. administration, thus suggesting a more preferential distribution of liposomal doxorubicin into the liver tumor with i.a. administration. By contrast, the heart, spleen, and plasma AUCs were decreased 3.8-, 3.2-, and 16-fold, respectively, after i.a. administration. Cumulative urinary excretion at 8 hr was also 14 times lower in animals that received liposomal doxorubicin i.a. In good correlation with these findings, i.a. administration markedly enhanced the anti-tumor effect of liposomal doxorubicin against liver W256 tumors as measured by tumor growth inhibition 5 days after treatment (-16% for i.a. administration vs. +89% for i.v. administration, p less than or equal to 0.05) and prolongation of survival (ILS: 108% for i.a. administration vs. 26% for i.v. administration, p less than or equal to 0.05). Our results show that i.a. administration of liposomal doxorubicin results in preferential distribution of the anti-tumor agent into the tumor tissue and increased anti-tumor activity, while increasing the cardioprotective effect of the liposome carrier by decreasing the plasma peak and heart-tissue levels of the drug.

[Diagnostic value of pulsed Doppler ultrasonography in atherosclerosis of the carotid arteries. A report of 200 cases]

An analysis of ultrasound imaging characteristics and carotid bloodflow parameters in 200 cases of carotid atherosclerosis was made. A high-resolution dual-function ultrasound image displaying instrument was used. It was found that the pulsed Doppler ultrasonography was useful and accurate to help diagnose the presence of extracranial carotid atherosclerotic plaques with narrowing of the carotid arteries. The ratios of the calibres of the internal carotid arteries and the common carotid arteries (IC/CC) could be taken as one of the specific indicators in determining those arteries showing calibre stenosis greater than 50%. Authors suggested that the features of carotid atherosclerosis plaques as identified in the Doppler ultrasonography could be divided into 4 types: 1. coarse type;2. soft type;3. hard type; and 4. mixed type.

EPR studies of spin-labeled bovine plasma amine oxidase: the nature of the substrate-binding site

The carbonyl cofactor of bovine plasma amine oxidase (EC 1.4.3.6), recently shown to be 6-hydroxydopa (also known as topa), has been spin labeled to the extent of one label per enzyme dimer molecule, using 4-amino-2,2,6,6-tetramethylpiperidine-N-oxyl (4-amino-TEMPO) and 4-hydrazino-TEMPO followed by reduction with borohydride. By studying the EPR spectra of the labeled enzyme, it has been deduced that there is no magnetic interaction between the copper and the spin label, and that the spin label is at least 1.3 nm distant from the copper(II) ion in the resting enzyme. The bound label is strongly immobilized, is in a sterically constricted environment, and is not accessible to small anions. Removal of the copper does not alter the EPR spectrum of the label. The results are similar to results for porcine plasma amine oxidase, and show that the copper is not close to, and does not directly interact with, the topa-bound substrate.

[Effect of baoshen wan on serum lipid peroxide levels in nephritis treated based on the differentiation-syndromes]

This paper deals with the treatment of 22 cases of chronic nephritis with Baoshen Wan (protecting kidney pills) according to the differentiation of syndromes; the results showed that 3 cases had got perfect remission, 6 cases fundamental remission, and 10 cases partial remission; thus its effective rate reached to 86.4%. Before treatment, the mean value of serum LPO of the 22 patients was 4.44 +/- 0.099 (means +/- S means, mumol/L), which compare with the normal value (3.69 +/- 0.075), P less than 0.05. After treatment, the serum LPO level was lowered to 3.95 +/- 0.11, P less than 0.05. It suggested that Baoshen Wan could disperse the free radical and lower the serum LPO level in the patients with chronic nephritis.