Malnutrition and cachexia are associated with poor CAR T-cell therapy outcomes including survival.

BACKGROUND & AIMS: Chimeric Antigen Receptor (CAR) T-cell therapy has emerged as a revolutionary treatment for patients with refractory or relapsed B-cell malignancies. However, a significant proportion of patients experience negative outcomes, including severe inflammatory toxicities and relapse. Cachexia and malnutrition are known secondary syndromes in many cancer patients, attributed to the effects of active malignancy, systemic inflammation, and cumulative treatment burden; however, further research is required to accurately characterise these issues in CAR T-cell patients. The aims of this service evaluation were to explore the changes in nutritional status (malnutrition and cachexia) in CAR T-cell therapy patients and the potential impact on patient outcomes including survival. Additionally, we describe the utilisation of dietetic resources in this specific patient population in a London tertiary referral centre. METHODS: Adult haematology patients receiving licensed CD19-targeting CAR T-cell therapy at University College London Hospital between 01/04/19 and 01/09/21 were included. Data were collected from the time of treatment consent, and throughout admission to day of discharge: body weight (BW), C-reactive protein, albumin, lactate dehydrogenase, nutrition-risk screening scores (hospital-specific) and dietetic input. Clinical outcomes such as 12-month all-cause mortality, intensive care unit (ICU) admission, high-grade toxicities, and length of hospital stay (LoS) were also recorded. Cachexia and malnutrition were defined using the modified Glasgow Prognostic Score (mGPS) and Global Leadership Initiative on Malnutrition (GLIM) consensus, respectively. RESULTS: 114 patients (55.6 ± 15.1 years; 57% males) with B-cell non-Hodgkin's lymphoma (n = 109) and B-cell acute lymphoblastic leukaemia (n = 5), receiving axicabtagene ciloleucel (n = 89) and tisagenlecleucel (n = 25) were included. Median LoS for treatment was 34 (27-38) days. Prior to treatment, 31.5% of patients developed malnutrition, with pre-cachexia/refractory cachexia (mGPS) identified in 43.6% of patients. This altered nutritional status pre-treatment was significantly associated with adverse patient outcomes post-infusion; mGPS was independently associated with inferior overall survival (HR = 3.158, CI = 1.36-7.323, p = 0.007), with malnutrition and mGPS associated with increased LoS (p = 0.037), sepsis (p = 0.022) and ICU admission (p = 0.039). During admission, patients experienced significant BW loss (-5.6% (-8.8 to -2.4); p=<0.001), with 68.4% developing malnutrition. Malnutrition screening during admission identified 57% patients at-risk, with 66.6% of patients referred to dietetics; however, there was a lack of malnutrition screening and dietetic referrals prior to treatment. CONCLUSION: Pre-treatment malnutrition and cachexia was significantly associated with adverse CAR T patient outcomes, including mGPS cachexia status independently associated with inferior overall survival. Further research in this novel space is essential to confirm the extent and impact of nutritional issues, to assist with implementing dietetic pathways, and to identify potential interventions with a view to optimising outcomes.

Sarcopenic Obesity and Depression: A Systematic Review.

BACKGROUND: Sarcopenic obesity (SO) is a condition combining two important public health issues commonly seen amongst older individuals, obesity and sarcopenia. Depressive symptoms are common among older people, whose population is increasing worldwide. Obesity and sarcopenia alone, are clearly associated with depression while the coexistence of these two conditions (SO) upon depressive disorders is currently unclear. We aimed to systematically review the association between primary SO and depressive disorders. METHODS: Searches were run on MEDLINE, EMBASE, PsycINFO, and CINAHL (inception to June 2019). One reviewer screened titles, abstracts, and full-texts, with 10% checked independently by a second reviewer. Cohort and cross-sectional studies were included. Two reviewers independently assessed risk of bias using the Mixed Methods Appraisal Tool. Results were narratively synthesised. RESULTS: Out of the 7 studies eligible for inclusion, evidence of sarcopenic obesity as a predictor of depressive symptoms was found in two studies. The main observed trend was that diagnosing sarcopenia using muscle strength led to significant associations between sarcopenic obesity and depressive symptoms. Two cross-sectional studies found a significant association between SO and depressive symptoms, whilst three others found no statistically significant associations. All possessed some methodological limitations. DISCUSSION: This is the first review to systematically examine a potential relationship between sarcopenic obesity and depressive disorders. Currently, the results are heterogeneous due to the large variability in assessment methods and outcome measurements. Future longitudinal studies would achieve greater confidence in the provisional conclusion that sarcopenic obesity, when measured using muscle strength, is associated with depressive symptoms.

Sucrose transport by Streptococcus mutans. Evidence for multiple transport systems.

The transport of sucrose by selected mutant and wild-type cells of Streptococcus mutans was studied using washed cocci harvested at appropriate phases of growth, incubated in the presence of fluoride and appropriately labelled substrates. The rapid sucrose uptake observed cannot be ascribed to possible extracellular formation of hexoses from sucrose and their subsequent transport, formation of intracellular glycogen-like polysaccharide, or binding of sucrose or extracellular glucans to the cocci. Rather, there are at least three discrete transport systems for sucrose, two of which are phosphoenolpyruvate-dependent phosphotransferases with relatively low apparent Km values and the other a non-phosphotransferase (non-PTS) third transport system (termed TTS) with a relatively high apparent Km. For strain 6715-13 mutant 33, the Km values are 6.25 X 10(-5) M, 2.4 X 10(-4) M, and 3.0 X 10(-3) M, respectively: strain NCTC-10449, the Km values are 7.1 X 10(-5) M, 2.5 X 10(-4) M and 3.3 X 10(-3) M, respectively. The two lower Km systems could not be demonstrated in mid-log phase glucose-adapted cocci, a condition known to repress sucrose-specific phosphotransferase activity, but under these conditions the highest Km system persists. Also, a mutant devoid of sucrose-specific phosphotransferase activity fails to evidence the two high affinity (low apparent Km) systems, but still has the lowest affinity (highest Km) system. There was essentially no uptake at 4 degrees C indicating these processes are energy dependent. The third transport system, whose nature is unknown, appears to function under conditions of sucrose abundance and rapid growth which are known to repress phosphoenolpyruvate-dependent sucrose-specific phosphotransferase activity in S. mutans. These multiple transport systems seem well-adapted to S. mutans which is faced with fluctuating supplies of sucrose in its natural habitat on the surfaces of teeth.

Tumor biology: use of tiled images in conjunction with measurements of cellular proliferation and death in response to drug treatments.

Tumor growth is dependent on the balance between cell proliferation and cell death, and these events occur heterogenously within an individual tumor. We present a methodology that provides integrative information about cell kinetics, cell death, and cell growth within individual tumors in animals treated with cytotoxic chemotherapeutic agents. Using HCT-116 and NCI-H460 cells, human colonic adenocarcinoma and non-small cell lung cells, respectively, traditional xenograft studies were performed. The tumor-bearing animals were treated with cyclophosphamide (Cytoxan), gemcitabine (Gemzar), or mitomycin C, and extensive analysis of the tumors was studied. Cell kinetics were evaluated by measuring the apoptotic and proliferation indices. The ability to image an entire tumor section using "tiling" by creating a large montage from many high-resolution images makes it possible to identify regional differences within areas of tumor and to demonstrate differences in these tumor regions after treatment with selected chemotherapeutic agents. Two specific areas within tumors have been identified: (a) areas of viable cells within the cell cycle, determined by bromodeoxyuridine and/or morphological characteristics determined by hematoxylin staining; and (b) areas of necrosis determined by the absence of bromodeoxyuridine and proliferating cell nuclear antigen-labeled cells coupled with morphological changes. By standardizing the tumor size to 100 mm2, different patterns of tumor responses to chemotherapeutic agents were determined. By creating such tiled images and by quantitating cell cycle kinetics, it is possible to gain a more complete understanding of tumor growth and response to treatment, leading to the development of more reliable methods for assessing the clinical behavior of anticancer drugs.

Differential antiplatelet efficacy for various GPIIb/IIIa antagonists: role of plasma calcium levels.

OBJECTIVES: The present study was undertaken to determine the effects of free ionized calcium influenced by either the anticoagulant used (citrate vs. heparin) or directly varying the calcium levels after treatment of blood with citrate on the antiplatelet efficacy of two classes of GPIIb/IIIa antagonists. METHODS: The platelet effects of changes in plasma [Ca(++)] with the different GPIIb/IIIa antagonists were determined using light transmittance aggregometry, direct binding kinetics, and (125)I-fibrinogen binding to activated human platelets. RESULTS: A significantly higher IC50s was shown with heparin (free ionized calcium=1.1 mM) as compared to that with citrate (free ionized calcium=0.12 mM) with class II GPIIb/IIIa antagonists (P<0.01) such as Orbofiban, and Integrilin. In contrast, class I GPIIb/IIIa antagonists such as Roxifiban and Abciximab showed no significant changes in their IC50s in either citrate or heparin. Similar data were shown with other non-calcium chelating anticoagulant such as PPACK as compared to that with heparin. Additionally, similar data were shown with regard to the [Ca(++)] sensitivity for GPIIb/IIIa antagonists from Class II but not Class I in the changes in IC50 values required for the inhibition of (125)I-fibrinogen binding to activated human gel filtered platelets. Additionally, examples from Class I GPIIb/IIIa antagonists such as (3)H-active form of Roxifiban showed no significant changes in its platelet binding affinity in response to change in [Ca(++)]. In contrast, GPIIb/IIIa antagonists from class II such as (3)H-active form of Orbofiban demonstrated significant changes (P<0.01) in its platelet binding kinetics and antiplatelet efficacy in response to changes in Ca(++) concentrations. CONCLUSIONS: These data suggest the impact of the method of blood collection or changes in plasma calcium levels on the antiplatelet efficacy for class II but not class I GPIIb/IIIa antagonists depending on their platelet binding kinetics.

The in vitro dental plaque inhibitory properties of a series of N-[1-alkyl-4(1H)-pyridinylidene]alkylamines.

A series of novel N-[1-alkyl-4(1H)-pyridinylidene]alkylamine hydrohalides has been prepared and evaluated as inhibitors of dental plaque formation, in vitro. Several members of the series exhibited potency ca. 9-fold greater than that of chlorhexidine vs Streptococcus sobrinus 6715-13. The di-n-octyl analogue, 11 (pirtenidine), was found to be highly efficacious against several other oral plaque-forming microorganisms and is presently undergoing preclinical evaluation.

Bispyridinamines: a new class of topical antimicrobial agents as inhibitors of dental plaque.

A series of N,N'-polyalkylenebis[4-(substituted-amino)pyridines] has been prepared, and members have been evaluated as potential anti-dental plaque agents. From among the most active members of the series, one compound, N,N'-[1,10-decanediyldi-1(4H)-pyridinyl-4-ylidene]bis(1-octanam ine) dihydrochloride, octenidine, was selected as a candidate for clinical study.

Antibacterials. Synthesis and structure-activity studies of 3-aryl-2-oxooxazolidines. 1. The "B" group.

The synthesis and structure/activity studies of the effect of varying the "B" group in a series of oxazolidinone antibacterials (I) are described. Two synthetic routes were used: (1) alkylation of aniline with glycidol followed by dialkyl carbonate heterocyclization to afford I (A = H, B = OH), whose arene ring was further elaborated by using electrophilic aromatic substitution methodology; (2) cycloaddition of substituted aryl isocyanates with epoxides to give A and B with a variety of values. I with B = OH or Br were converted to other "B" functionalities by using SN2 methodology. Antibacterial evaluation of compounds I with A = acetyl, isopropyl, methylthio, methylsulfinyl, methylsulfonyl, and sulfonamido and a variety of different "B" groups against Staphylococcus aureus and Enterococcus faecalis concluded that the compounds with B = aminoacyl, and particularly acetamido, were the most active of those examined in each A series, possessing MICs in the range of 0.5-4 micrograms/mL for the most active compounds described.

Antibacterials. synthesis and structure-activity studies of 3-aryl-2-oxooxazolidines. 4. Multiply-substituted aryl derivatives.

The synthesis and structure-activity relationship (SAR) studies of the effect of different polysubstitution patterns in the aromatic ring of 5-(acetamidomethyl)oxazolidinone antibacterials (I) on antibacterial activity are presented. Compounds I were prepared by the six-step synthesis described previously (Gregory, W. A.; et al. J. Med. Chem. [formula: see text] 1989, 32, 1673), electrophilic aromatic substitution reactions of 3-substituted compounds, and functional-group interchange reactions of 3,4-disubstituted compounds. Antibacterial evaluation of compounds I against Staphylococcus aureus and Enterococcus faecalis gave the following results. The 2,4- and 2,5-disubstituted derivatives have weak or no antibacterial activity. Antibacterial activities of 3,4-disubstituted compounds are comparable to those of the 4-monosubstituted analogues for small 3-substituents (smaller than Br), but decline rapidly for larger 3-substituents. 3,4-Annulated derivatives are comparable in activity to their open-chain analogues. 3,5-Disubstituted and 3,4,5- and 2,4,6-trisubstituted derivatives are devoid of antibacterial activity.

Platelet GPIIb/IIIa binding characteristics of small molecule RGD mimetic: distinct binding profile for Roxifiban.

A number of non-peptide orally active RGD mimetic prodrug such as Orbofiban, Sibrafiban, SR121566, Roxifiban and others entered into the clinical evaluation stage. Some of these agents were terminated and some are still in clinical trials. The present study examined the platelet GPIIb/IIIa binding profiles for the active form of Roxifiban, Sibrafiban, SR121566 and Orbofiban using 3H-Roxifiban active form (XV459), 3H-DMP728, 125I-Echistatin, and 125I-Fibrinogen. Either DMP728, Orbofiban, Sibrafiban, SR121566 or Roxifiban active form as well as other RGD mimetic bind to the same binding site(s) on human platelets as evident from the competitive inhibition of binding of each other to human platelet. Additionally, Roxifiban active form competed with FITC labeled GPIIb/IIIa antagonist cyclic RGD peptidomimetic (XL086) as demonstrated using confocal microscopy technique. Roxifiban active form (XV459) demonstrated the highest potency in inhibiting 3H-XV459, 3H-DMP728, 125I-Echistatin, and 125I-Fibrinogen binding to human platelets as compared to the others. Structure activity relationship within the isoxazoline Roxifiban series showed that substituent at the alpha-carbon next to the carboxy terminal represents an exosite for the affinity binding to human platelets leading to slow platelet dissociation rate. These data indicated a distinct binding profile for Roxifiban (high affinity to both activated and resting platelets associated with a relatively slow K(off)) as compared to others. These differences might determine the pharmacodynamics and pharmackokinetics of the different GPIIb/IIIa antagonists.

Selective inhibition of bacterial dihydroorotate dehydrogenases by thiadiazolidinediones.

Dihydroorotate dehydrogenase is a critical enzyme of de novo pyrimidine biosynthesis in prokaryotic and eukaryotic cells. Differences in the primary structure of the enzymes from Gram-positive and -negative bacteria and from mammals indicate significant structural divergence among these enzymes. We have identified a class of small molecules, the thiadiazolidinediones, that inhibit prototypical enzymes from Gram-positive and -negative bacteria, but are inactive against the human enzyme. The most potent compound in our collection functioned as a time-dependent irreversible inactivator of the bacterial enzymes with k(inact)/K(i) values of 48 and 500 M(-1) sec(-1) for the enzymes from Escherichia coli and Enterococcus faecalis, respectively. The data presented here indicate that it is possible to inhibit prokaryotic dihydroorotate dehydrogenases selectively while sparing the mammalian enzyme. Thus, this enzyme may represent a valuable target for the development of novel antibiotic compounds.

Small molecule alpha(v) integrin antagonists: novel anticancer agents.

The members of the integrin family are targets that potentially provide both therapeutic and diagnostic opportunities. Advances in the understanding of the signalling pathways, transcriptional regulation and the structure/function relationships of the adhesion molecules to extracellular matrix proteins have all contributed to these opportunities. The role of the integrins in pathological processes in both acute and chronic diseases, include ocular, cancer (solid tumours and metastasis), cardiovascular (stroke and heart failure) and inflammatory (rheumatoid arthritis) conditions. Various therapeutic candidates, including antibodies, cyclic peptides and peptidomimetics, have been identified. This review will focus on the key role of the alpha(v) integrin (alpha(v)beta(3) and alpha(v)beta(5)) in angiogenic processes in tumours, including its potential use in cancer diagnostics and therapy.

Alpha(v)beta(3) integrin in angiogenesis and restenosis.

Various integrins are thought to be intimately involved in several pathological processes, including cancers (solid tumors and metastasis), cardiovascular diseases (stroke and heart failure), inflammatory diseases (rheumatoid arthritis) and ocular pathologies. The mechanism of the involvement of integrins in these acute and chronic disease states is slowly being elucidated. Recently, various therapeutic candidates, including antibodies, cyclic peptides and peptidomimetics, have been clinically evaluated and have been shown to successfully modulate certain disease processes. This review focuses on the key role of the alpha(v) integrin (alpha(v)beta(3)) in the angiogenic processes in diseases such as cancer, restenosis following percutaneous transluminal coronary angioplasty, stroke, ocular disease and rheumatoid arthritis.

The hollow fiber assay: continued characterization with novel approaches.

The hollow fiber assay, a unique in vivo model, permits the simultaneous evaluation of compound efficacy against multiple cell lines in two physiological compartments. This assay has been used to characterize in vivo activity of cytotoxic compounds. The purpose of the present study was to characterize and optimize this assay for compounds with a defined mechanism of action, specifically cell cycle inhibition. Two human tumor cell lines and one normal human cell line were loaded into polyvinylidene fluoride hollow fibers at two or more cell concentrations and grown in mice for 3-10 days. The data demonstrate the importance of characterizing the initial loading density of various cell lines in the evaluation of compounds. All studies were performed with cells in the linear part of the cell growth curves. Initial loading densities of 1-2 x 10(4) cells/fiber gave the greatest opportunity for growth in the three human cell lines tested (HCT116 colon carcinoma, NCI-H460 non-small cell carcinoma, and AG 1523 normal fibroblast). Utilizing the MTT assay, standard curves were constructed to correlate the final number of cells with optical density (OD) readings at 540 nm in order to calculate cell numbers in the fibers. Insights into the mechanism of action of cisplatin have been gained using Western blot analysis of the cell cycle markers PCNA (a protein present throughout the cell cycle) and Rb (a protein that acts as a tumor suppressor gene product) from the hollow fiber cells. In cisplatin-treated NCI-H460 cells both PCNA and Rb phosphorylation decreased, suggesting the arrest of the cells prior to the S phase. Standard therapeutic agents, cisplatin, racemic flavopiridol, cyclophosphamide and mitomycin C, were evaluated independently in the hollow fiber assay and the xenograft model. The data demonstrate that compounds active in the hollow fiber assay are also active in the xenograft.

Regulation of gene expression and cell growth in vivo by tetracycline using the hollow fiber assay.

The hollow fiber assay presents a potentially unique tool to study the effects of regulated gene expression in cell lines that do not form tumors in vivo. The hollow fibers allow small molecules to pass freely through while keeping the cells within the fibers and segregated from host cells. OSp16.1 cells, derived from the U24 clone of the U2-OS osteogenic sarcoma tumor line, express the p16INK4a tumor suppressor under the regulation of tetracycline (tet) (Mitra J et al. Mol Cell Bio 19:3916, 1999). The in vitro induction of p16 in the OSp16.1 cell line is regulated by tet. The hollow fiber assay was used to determine whether the regulation of the p16 gene could be achieved in vivo, since these cells did not grow in the xenograft model. There were no differences in the in vivo growth pattern of U24 cells loaded into the hollow fibers with and without tet: 807% and 839% net growth, respectively. OSp16.1 cells in fibers in mice receiving 3.33 mg/kg/day tet had a 644% net growth after 21 days. There was a 194% net growth without tet. Immunoblotting of extracts prepared from the hollow fibers confirmed that p16 was induced in the absence of tet. These data demonstrate this assay is a useful tool for studying the effects of regulated gene expression in vivo.

Novel small molecule alpha v integrin antagonists: comparative anti-cancer efficacy with known angiogenesis inhibitors.

Recent evidence supports the involvement of integrins in angiogenesis: blockade of alpha v beta 3 and alpha v beta 5 integrins disrupts angiogenesis leading to decreased blood vessel formation and hence decreased tumor growth. We hypothesized that av antagonists could inhibit tumor growth in tumor cells devoid of alpha v beta 3 integrins. We evaluated SM256 and SD983, novel small molecules that are specific av antagonists in mouse models of angiogenesis and tumorigenesis, and compared them with standards: TNP470, a fumagillin analog in the clinic, and flavopiridol, a cell cycle kinase inhibitor. In vitro SM256 was a selective alpha v beta 3 inhibitor with an IC50 = 4nM, and the affinity of SD983 against the mouse endothelial alpha v beta 3 integrin yielded an IC50 = 2nM and an IC50 = 54nM against alpha v beta 5. In the mouse Matrigel model of angiogenesis SM256 decreased blood vessel formation (hemoglobin content) with an ED50 = 0.055 ug/kg/day, tenfold more potent than TNP470. SG545, an ester of SD983, decreased blood vessel formation with an ED50 = 6 ug/kg/day, while flavopiridol ED50 = 18 ug/kg/day. In the mouse xenograft model, using human colon carcinoma RKO cells that do not express alpha v beta 3 but express alpha v beta 5, tumor growth was inhibited by SG545 (10 mg/kg/day) and flavopiridol (5 mg/kg/every other day) 40% and 70%, respectively (p < 0.05). Although the proliferative index (measured by BrdU incorporation) was not significantly changed with SM256, SG545 or flavopiridol (29-32%), the apoptotic index increased significantly (p < 0.05) in the SM256 and SG545-treated groups (2.3-2.7%) compared with controls (1.1%), suggesting increased cell death contributed to decreased tumor volumes. Neovascularization decreased with SM256 and SG545 treatment. The data demonstrate that potent selective av antagonist can target endothelial cells, tumor cells, inhibit angiogenesis and inhibit tumor growth.

Predictors of hearing threshold levels and distortion product otoacoustic emissions among noise exposed young adults.

AIM: To examine the relations between noise exposure and other risk factors with hearing function as measured by audiometric thresholds and distortion product otoacoustic emissions. METHODS: A total of 456 subjects were studied (393 apprentices in construction trades and 63 graduate students). Hearing and peripheral auditory function were quantified using standard, automated threshold audiometry, tympanometry, and distortion product otoacoustic emissions (DPOAEs). The analysis addressed relations of noise exposure history and other risk factors with hearing threshold levels (HTLs) and DPOAEs at the baseline test for the cohort. RESULTS: The cohort had a mean age of 27 (7) years. The construction apprentices reported more noise exposure than students in both their occupational and non-occupational exposure histories. A strong effect of age and years of work in construction was observed at 4, 6, and 8 kHz for both HTLs and DPOAEs. Each year of construction work reported prior to baseline was associated with a 0.7 dB increase in HTL or 0.2 dB decrease DPOAE amplitude. Overall, there was a very similar pattern of effects between the HTLs and DPOAEs. CONCLUSIONS: This analysis shows a relatively good correspondence between the associations of noise exposures and other risk factors with DPOAEs and the associations observed with pure-tone audiometric thresholds in a young adult working population. The results provide further evidence that DPOAEs can be used to assess damage to hearing from a variety of exposures including noise. Clarifying advantages of DPOAEs or HTLs in terms of sensitivity to early manifestations of noise insults, or their utility in predicting future loss in hearing will require longitudinal follow up.

The repressible metabolism of sorbitol (D-glucitol) by intact cells of the oral plaque-forming bacterium Streptococcus mutans.

Sorbitol metabolism of Streptococcus mutans was studied. Cocci adapted to growth in sorbitol, glucose or both were challenged to grow on and to ferment those carbohydrates in pH-controlled defined media with intact cells capable of metabolic inductions and regulations. Glucose degradation when in high concentration did not depend upon induction of glucose-specific phosphoenolpyruvate-dependent phosphotransferase activity, as it did at low glucose concentrations. Sorbitol utilization was signalled by the induction of sorbitol-specific phosphoenolpyruvate-dependent phosphotransferase and sorbitol-6-phosphate dehydrogenase activities which persisted throughout the growth cycle. However, when even low levels of glucose were present, sorbitol transport and catabolic activities were rapidly repressed and they were not de-repressed until essentially all glucose had been utilized. Metabolism of sorbitol thus relies on the sorbitol phosphotransferase/sorbitol-6-phosphate dehydrogenase pathway whose activity is sensitively repressed in the presence of glucose.

Vascular endothelial growth factor in porcine coronary arteries following balloon angioplasty.

The present study was a preliminary inquiry into the presence of vascular endothelial growth factor (VEGF) in a model of coronary artery response to injury. We examined domestic pigs who had received a diet enriched in saturated fat and cholesterol and undergone balloon angioplasty of one or more coronary arteries. Immunohistochemical analysis of the coronary arteries 2 months after injury revealed the presence of VEGF distributed throughout the media and neointima of the angioplasty lesions and in association with blood vessels in the adventitia and those vessels growing into the base of the neointima. VEGF was also detected in areas of dietary-induced intimal proliferation. This study provided the first immunochemical demonstration of VEGF occuring naturally in a pig model of coronary response to injury.

An automated pulse labelling method for structure-activity relationship studies with antibacterial oxazolidinones.

The 3-aryl-2-oxooxazolidinones are a new class of synthetic antibacterial agents that potently inhibit protein synthesis. An automated pulse labelling method with [3H]-lysine was developed with Bacillus subtilis to obtain additional quantitative activity data for structure-activity relationship studies with the oxazolidinones. Inhibition constants were calculated after a Logit fit of the data into the formula: % of control = 100/(1 + e[-B(X - A)]), where B is the slope of the model, X is the natural log of the inhibitor concentration and A is the natural log of the inhibitor concentration required to inhibit protein synthesis by 50% (ln IC50). When substituents at the 5-methyl position of the heterocyclic ring (B-substituent) were NHCOCH3, OH or Cl, the correlation coefficient was 0.87 between the MIC and IC50 values (for all compounds with MICs less than or equal to 16 micrograms/ml). The D-isomers of DuP 721 (A-substituent = CH3CO) and DuP 105 (A-substituent = CH3SO) gave MICs of 128 micrograms/ml and IC50s of greater than or equal to 50 micrograms/ml for protein synthesis, showing that only the L-isomers were active. By MIC testing, oxazolidinones with the B-substituent of NHCOCH3 and the A-substituent of CH3CO, NO2, CH3S, CH3SO2 or (CH3)2CH had comparable antibacterial potency; however, pulse labelling analysis showed that compounds with an A-substituent of CH3CO or NO2 were more potent inhibitors of protein synthesis.