A mechanistic look at the effects of adversity early in life on cardiovascular disease risk during adulthood.

Early origins of adult disease may be defined as adversity or challenges during early life that alter physiological responses and prime the organism to chronic disease in adult life. Adverse childhood experiences or early life stress (ELS) may be considered a silent independent risk factor capable of predicting future cardiovascular disease risk. Maternal separation (MatSep) provides a suitable model to elucidate the underlying molecular mechanisms by which ELS increases the risk to develop cardiovascular disease in adulthood. The aim of this review is to describe the links between behavioural stress early in life and chronic cardiovascular disease risk in adulthood. We will discuss the following: (i) adult cardiovascular outcomes in humans subjected to ELS, (ii) MatSep as an animal model of ELS as well as the limitations and advantages of this model in rodents and (iii) possible ELS-induced mechanisms that predispose individuals to greater cardiovascular risk. Overall, exposure to a behavioural stressor early in life sensitizes the response to a second stressor later in life, thus unmasking an exaggerated cardiovascular dysfunction that may influence quality of life and life expectancy in adulthood.

Epigenetics and transgenerational transfer: a physiological perspective.

Epigenetics, the transgenerational transfer of phenotypic characters without modification of gene sequence, is a burgeoning area of study in many disciplines of biology. However, the potential impact of this phenomenon on the physiology of animals is not yet broadly appreciated, in part because the phenomenon of epigenetics is not typically part of the design of physiological investigations. Still enigmatic and somewhat ill defined is the relationship between the overarching concept of epigenetics and interesting transgenerational phenomena (e.g. 'maternal/parental effects') that alter the physiological phenotype of subsequent generations. The lingering effect on subsequent generations of an initial environmental disturbance in parent animals can be profound, with genes continuing to be variously silenced or expressed without an associated change in gene sequence for many generations. Known epigenetic mechanisms involved in this phenomenon include chromatin remodeling (DNA methylation and histone modification), RNA-mediated modifications (non-coding RNA and microRNA), as well as other less well studied mechanisms such as self-sustaining loops and structural inheritance. In this review we: (1) discuss how the concepts of epigenetics and maternal effects both overlap with, and are distinct from, each other; (2) analyze examples of existing animal physiological studies based on these concepts; and (3) offer a construct by which to integrate these concepts into the design of future investigations in animal physiology.

Oral uracil and Ftorafur plus leucovorin: pharmacokinetics and toxicity in patients with metastatic cancer.

PURPOSE: To assess the pharmacokinetics of Ftorafur (tegafur, FT), 5-fluorouracil (5-FU), and uracil in 31 cancer patients who were enrolled in phase I studies of oral uracil and FT (UFT). The correlation between pharmacokinetic parameters and toxic effects of UFT was evaluated. METHODS: Uracil and FT were orally administered in a 4:1 molar ratio at FT doses of 200-400 mg/m2 per day. Patients also received leucovorin at 150 mg/day. Daily doses were divided into three doses and administered at 8-h intervals for 28 consecutive days. Plasma FT concentrations were measured by high-performance liquid chromatography, and plasma 5-FU and uracil concentrations were determined using gas chromatography-mass spectrometry. National Institutes of Health Common Toxicity Criteria were used for assessment of toxicity. RESULTS: The concentrations of FT, 5-FU, and uracil showed wide interpatient variations. Maximum plasma concentrations (Cp(max)) of all three compounds were achieved in 0.3 to 4.0 h. At the various study doses, the terminal half-life (t 1/2beta) of FT ranged from 3.9 to 5.9 h, the area under the concentration-versus-time curve (AUC0-6h) ranged from 16,220 to 52,446 (ng/ml)h, the total clearance (ClT) ranged from 100 to 175 ml/min, and the steady-state volume of distribution (Vd(ss)) ranged from 18.3 to 28.7 l. The 5-FU generated from FT had an apparent distribution half-life (t 1/2alpha) and an apparent elimination half-life (t 1/2beta) of 0.3-1.3 h and 4.9-7.0 h, respectively. The AUC0-6h of 5-FU ranged from 120 to 325 (ng/ml)h. Uracil had a t 1/2alpha of 0.2-0.5 h and the level quickly returned to the endogenous level. The AUC0-6h for uracil ranged from 605 to 3764 (ng/ml)h, the ClT ranged from 3225 to 7748 ml/min, and the Vd(ss) ranged from 341 to 1354 l. The Cp(max) and AUC0-6h of both FT and uracil were significantly correlated with FT doses (P-values of 0.0244 and 0.0112) and with uracil doses (P-values of 0.0346 and 0.0083), respectively. In addition to interpatient variations, intrapatient variations were also observed in six patients who had pharmacology studies done on days 1 and 26+/-2 at the same study dose. We found that the repeated treatment with UFT caused cumulative increases in the values of Cp(max), Ctrough, and AUC0-6h of FT and 5-FU. The major toxic effects observed were diarrhea and nausea and vomiting. The occurrence of these toxic effects correlated significantly with the Cp(max) and AUC0-6h of 5-FU. CONCLUSIONS: The pharmacology studies showed that FT and uracil were readily absorbed orally and that FT was rapidly converted to 5-FU. The preliminary findings suggest that determination of plasma levels of 5-FU after oral administration of UFT may help predict subsequent toxic effects.

A binding site for the kringle II domain of prothrombin in the apple 1 domain of factor XI.

Previously we defined binding sites for high molecular weight kininogen (HK) and thrombin in the Apple 1 (A1) domain of factor XI (FXI). Since prothrombin (and Ca(2+)) can bind FXI and can substitute for HK (and Zn(2+)) as a cofactor for FXI binding to platelets, we have attempted to identify a prothrombin-binding site in FXI. The recombinant A1 domain (rA1, Glu(1)-Ser(90)) inhibited the saturable, specific and reversible binding of prothrombin to FXI, whereas neither the rA2 domain (Ser(90)-Ala(181)), rA3 domain (Ala(181)-Val(271)), nor rA4 domain (Phe(272)-Glu(361)) inhibited prothrombin binding to FXI. Kinetic binding studies using surface plasmon resonance showed binding of FXI (K(d) approximately 71 nm) and the rA1 domain (K(d) approximately 239 nm) but not rA2, rA3, or rA4 to immobilized prothrombin. Reciprocal binding studies revealed that synthetic peptides (encompassing residues Ala(45)-Ser(86)) containing both HK- and thrombin-binding sites, inhibit (125)I-rA1 (Glu(1)-Ser(90)) binding to prothrombin, (125)I-prothrombin binding to FXI, and (125)I-prothrombin fragment 2 (Ser(156)-Arg(271)) binding to FXI. However, homologous prekallikrein-derived peptides (encompassing Pro(45)-Gly(86)) did not inhibit FXI rA1 binding to prothrombin. The peptides Ala(45)-Arg(54), Phe(56)-Val(71), and Asp(72)-Ser(86), derived from sequences of the A1 domain of FXI, acted synergistically to inhibit (125)I-rA1 binding to prothrombin. Mutant rA1 peptides (V64A and I77A), which did not inhibit FXI binding to HK, retained full capacity to inhibit rA1 domain binding to prothrombin, and mutant rA1 peptides Ala(45)-Ala(54) (D51A) and Val(59)-Arg(70) (E66A), which did not inhibit FXI binding to thrombin, retained full capacity to inhibit rA1 domain binding to prothrombin. Thus, these experiments demonstrate that a prothrombin binding site exists in the A1 domain of FXI spanning residues Ala(45)-Ser(86) that is contiguous with but separate and distinct from the HK- and thrombin-binding sites and that this interaction occurs through the kringle II domain of prothrombin.

The role of high molecular weight kininogen and prothrombin as cofactors in the binding of factor XI A3 domain to the platelet surface.

We have reported that prothrombin (1 microm) is able to replace high molecular weight kininogen (45 nm) as a cofactor for the specific binding of factor XI to the platelet (Baglia, F. A., and Walsh, P. N. (1998) Biochemistry 37, 2271-2281). We have also determined that prothrombin fragment 2 binds to the Apple 1 domain of factor XI at or near the site where high molecular weight kininogen binds. A region of 31 amino acids derived from high molecular weight kininogen (HK31-mer) can also bind to factor XI (Tait, J. F., and Fujikawa, K. (1987) J. Biol. Chem. 262, 11651-11656). We therefore investigated the role of prothrombin fragment 2 and HK31-mer as cofactors in the binding of factor XI to activated platelets. Our experiments demonstrated that prothrombin fragment 2 (1 microm) or the HK31-mer (8 microm) are able to replace high molecular weight kininogen (45 nm) or prothrombin (1 microm) as cofactors for the binding of factor XI to the platelet. To localize the platelet binding site on factor XI, we used mutant full-length recombinant factor XI molecules in which the platelet binding site in the Apple 3 domain was altered by alanine scanning mutagenesis. The recombinant factor XI with alanine substitutions at positions Ser(248), Arg(250), Lys(255), Leu(257), Phe(260), or Gln(263) were defective in their ability to bind to activated platelets. Thus, the interaction of factor XI with platelets is mediated by the amino acid residues Ser(248), Arg(250), Lys(255), Leu(257), Phe(260), and Gln(263) within the Apple 3 domain.

Factor XI binding to activated platelets is mediated by residues R(250), K(255), F(260), and Q(263) within the apple 3 domain.

To localize the platelet binding site on factor XI, rationally designed, conformationally constrained synthetic peptides were used to compete with [(125)I]factor XI binding to activated platelets. The major platelet binding energy resided within the sequence of amino acids T(249)-F(260). Homology scanning, using prekallikrein amino acid substitutions within the synthetic peptide T(249)-F(260), identified a major role for R(250) in platelet binding. Inhibition of [(125)I]factor XI binding to activated platelets by the recombinant Apple 3 domain of factor XI and inhibition by unlabeled factor XI were identical, whereas the recombinant Apple 3 domain of prekallikrein had little effect. A "gain-of-function" chimera in which the C-terminal amino acid sequence of the Apple 3 domain of prekallikrein was replaced with that of factor XI was as effective as the recombinant Apple 3 domain of factor XI and unlabeled factor XI in inhibiting [(125)I]factor XI binding to activated platelets. Alanine scanning mutagenic analysis of the recombinant Apple 3 domain of factor XI indicated that amino acids R(250), K(255), F(260), and Q(263) (but not K(252) or K(253)) are important for platelet binding. Thus, the binding energy mediating the interaction of factor XI with platelets is contained within the C-terminal amino acid sequence of the Apple 3 domain (T(249)-V(271)) and is mediated in part by amino acid residues R(250), K(255), F(260), and Q(263).

Susceptibility surveillance among gram-negative bacilli at a cancer center.

We conducted a survey of susceptibility among 758 gram-negative bacilli (GNB; collected from cancer patients over a 3-month period) to commonly used antibiotics. The overall resistance among GNB was least for piperacillin/tazobactam and meropenem (5 and 6%, respectively) followed by cefepime (8%), imipenem (9%), amikacin (12%), ofloxacin (13%), ciprofloxacin, ceftazidime and ticarcillin/clavulanate (14% each), aztreonam (18%) and tobramycin (24%). In comparison to data on antibiotic resistance to ceftazidime, imipenem, ciprofloxacin and aztreonam in similar studies in 1985 and 1994, resistance has significantly increased to all four antibiotic classes. Based on our current study, meropenem, cefepime, imipenem and piperacillin/tazobactam would be the most appropriate choices in our institution for empiric therapy of GNB infections in febrile neutropenic patients.

Expression of ataxin-2 in brains from normal individuals and patients with Alzheimer's disease and spinocerebellar ataxia 2.

Spinocerebellar ataxia type 2 (SCA2) is caused by expansion of a CAG trinucleotide repeat located in the coding region of the human SCA2 gene. The SCA2 gene product, ataxin-2, is a basic protein with two domains (Sm1 and Sm2) implicated in RNA splicing and protein interaction. However, the wild-type function of ataxin-2 is yet to be determined. To help clarify the function of ataxin-2, we produced antibodies to three antigenic peptides of ataxin-2 and analyzed the expression pattern of ataxin-2 in normal and SCA2 adult brains and cerebellum at different developmental stages. These studies revealed that (1) both wild-type and mutant forms of ataxin-2 were synthesized; (2) the wild-type ataxin-2 was localized in the cytoplasm in specific neuronal groups with strong labeling of Purkinje cells; (3) the level of ataxin-2 increased with age in Purkinje cells of normal individuals; and (4) ataxin-2-like immunoreactivity in SCA2 brain tissues was more intense than in normal brain tissues, and intranuclear ubiquitinated inclusions were not seen in SCA2 brain tissues.

Comparison of 5-fluorouracil pharmacokinetics in patients receiving continuous 5-fluorouracil infusion and oral uracil plus N1-(2'-tetrahydrofuryl)-5-fluorouracil.

Plasma 5-fluorouracil (5-FU) levels were compared in the same patients after approximately equimolar doses (1.9 mmol/ m2/day) of 5-day continuous i.v. infusion of 5-FU (CIFU) and oral administration of a formulation of two combined pharmacological agents, uracil (U) plus N1-(2'-tetrahydrofuryl)-5-fluorouracil (ftorafur or FT), a prodrug of 5-FU. Ten patients received CIFU for 5 days, then, after a week wash-out period, began the 28-day oral UFT regimen, which was given in three daily divided doses. Following 1 h of CIFU, the plasma 5-FU levels reached a steady state of 0.6+/-0.2 microM (mean+/-SD; day 1), which was maintained for the entire 5-day infusion period (0.6+/-0.1 microM). In contrast, the maximum 5-FU concentrations (Cpmax) generated from oral UFT at 1 h after dose administration on days 1 and 5 were 2.1+/-1.5 microM and 2.3+/-1.9 microM, respectively, which were higher than the steady-state levels during CIFU. These high 5-FU levels disappeared with an apparent elimination half-life (tl/2,beta) of 5.2+/-2.4 h (day 1) and 7.2+/-3.9 h (day 5). On day 1 of both regimens, CIFU patients had significantly larger 5-FU area under the concentration versus time curve (AUC0-8h) values (4.4+/-1.3 microM.h) than the AUC value when they received the UFT regimen (2.6+/-1.7 microM.h; P = 0.02). However, by day 5, there were no significant differences between AUC0-8 h values in patients receiving CIFU and UFT, respectively (4.8+/-1.5 microM.h versus 3.8+/-2.2 microM.h; P = 0.30)]. On day 5, the average concentration of the metabolite 5-FU at steady-state (Css,aver) within dose interval of 8 h (0.48+/-0.28 microM) for the oral UFT treatment is comparable with the Cpss values of 5-FU from CIFU-treated patients. The post-UFT generated 5-FU pharmacokinetic parameters (higher Cp(mx, comparable Css,aver, equal AUC values, and longer apparent t1/2,beta of 5-FU) may make oral UFT a preferred method of delivering this fluoropyrimidine over CIFU. In addition, oral UFT would eliminate the incidence of venous thrombosis and catheter-related infections sometimes seen in patients treated with CIFU. Furthermore, the convenience and decreased cost of oral administration may be preferable for many patients, particularly those receiving 5-FU for palliation.

A binding site for heparin in the apple 3 domain of factor XI.

Since heparin potentiates activated factor XI (FXIa) inhibition by protease nexin-2 by providing a template to which both proteins bind (Zhang, Y., Scandura, J. M., Van Nostrand, W. E., and Walsh, P. N. (1997) J. Biol. Chem. 272, 26139-26144), we examined binding of factor XI (FXI) and FXIa to heparin. FXIa binds to heparin (Kd approximately 0.7 x 10(-9) M) >150-fold more tightly than FXI (Kd approximately 1.1 x 10(-7) M). To localize the heparin-binding site on FXI, rationally designed conformationally constrained synthetic peptides were used to compete with 125I-FXI binding to heparin. A peptide derived from the Apple 3 (A3) domain of FXI (Asn235-Arg266) inhibited FXI binding to heparin (Kd approximately 3.4 x 10(-6) M), whereas peptides from the A1 domain (Phe56-Ser86), A2 domain (Ala134-Ala176), and A4 domain (Ala317-Gly350) had no such effect. The recombinant A3 domain (rA3, Ala181-Val271) inhibited FXI binding to heparin (Ki approximately 1.4 x 10(-7) M) indicating that all the information necessary for FXI binding to heparin is contained entirely within the A3 domain. The A3 domain also contains a platelet-binding site (Asn235-Arg266), consisting of three surface-exposed loop structures, Pro229-Gln233, Thr741-Leu246, and Thr249-Phe260 (Baglia, F. A., Jameson, B. A., and Walsh, P. N. (1995) J. Biol. Chem. 270, 6734-6740). Only peptide Thr249-Phe260 (which contains a heparin binding consensus sequence, RIKKSKA) inhibits FXI binding to heparin (Ki = 2.1 x 10(-7) M), whereas peptides Pro229-Gln233 and Thr241- Leu246 had no effect. Fine mapping of the heparin-binding site using prekallikrein analogue amino acid substitutions of the synthetic peptide Thr249-Phe260 and alanine scanning of the recombinant A3 indicated that the amino acids Lys252 and Lys253 are important for heparin binding. Thus, the sequence Thr249-Phe260 which contains most of the binding energy for FXI interaction with platelets also mediates the binding of FXI to heparin.

Phase I trial of uracil-tegafur (UFT) plus oral leucovorin: 28-day schedule.

UFT [Taiho Pharmaceutical Co. Ltd., Tokyo, Japan; (BMS-200604), Bristol-Myers Squibb, Princeton, NJ], a fluorouracil prodrug, is an oral 4:1 molar concentration of uracil plus tegafur. This study examined the dose-limiting toxic effects and maximum tolerated dose of UFT plus leucovorin administered for 28 consecutive days followed by a 7-day rest period. A course of therapy was repeated every 35 days. UFT dose levels examined were 200 mg/m2/day, with planned escalations to 250, 300, 350, and 400 mg/m2/day; the leucovorin dose remained at 150 mg/day. Three patients were initially enrolled at each UFT dose level. The total daily doses of both UFT and leucovorin were divided into three doses administered every 8 hr. Diarrhea became the dose-limiting toxicity at 400 mg/m2/day UFT, with grade 3 diarrhea noted in 2 of the 3 patients receiving that dose. To further define a phase II UFT starting dose, 3 additional patients were entered at the 350 mg/m2 level; 3 of the 6 patients treated at this level developed grade 3 nonhematological toxic effects. No partial or complete responses were observed. The recommended phase II UFT starting dose is 300 mg/m2/day plus 150 mg/day leucovorin. Since neutropenia, significant mucositis, and "hand-foot syndrome" were not observed with UFT plus leucovorin, the toxicity profile of this regimen appears favorable compared with that of intravenous regimens of fluorouracil plus leucovorin. This phase I trial of UFT served as the basis for a phase II trial, current phase III trials, and a national adjuvant therapy trial of UFT for high-risk colon cancer patients.

Neuronal expression and intracellular localization of presenilins in normal and Alzheimer disease brains.

The expression patterns of presenilin 1 (PS1) and presenilin 2 (PS2) in human normal and Alzheimer disease (AD) brains were investigated using antibodies to specific N-terminal peptides of PS1 (Alzh14A and Alzh14B) and PS2 (Alzh1A-AB). The antibodies to peptides Alzh14A (Alzh14A-AB) and Alzh14B (Alzh14B-AB) detected the full-length protein (approximately 63 kDa) and the N-terminal-processed fragment (36 kDa) of PS1, while the Alzh1A-AB detected mainly the N-terminal-processed fragment (36 kDa) of PS2. Immunofluorescent staining detected by confocal microscopy suggested that both native PS1 and PS2 are localized mainly in the Golgi/ER apparatus. Immunohistochemical studies of human temporal lobes from 2 normal and 5 sporadic Alzheimer brains revealed high levels of PS1 and PS2 expression in the granule cell layer and pyramidal neurons of the hippocampus. Strong immunoreactivity was found in reactive astrocytes and neurofibrillary tangles of all 5 Alzheimer brains. In contrast, only 2 sporadic Alzheimer brains showed presenilin-positive neuritic plaques. These observations suggest that presenilins may be involved in the pathology of some cases of sporadic AD.

In-vitro activity of trovafloxacin against clinical bacterial isolates from patients with cancer.

The antibacterial activity of trovafloxacin was compared with that of ciprofloxacin, levofloxacin, ofloxacin, sparfloxacin and norfloxacin against bacterial isolates from patients with cancer. In general, the activity of trovafloxacin was comparable to that of ciprofloxacin, levofloxacin and sparfloxacin against most Gram-negative isolates tested (minor differences in the activity of each agent against individual species were seen) and it was the most active agent tested against Stenotrophomonas maltophilia, inhibiting 80% of these isolates at <2.0 mg/L. Trovafloxacin was also the most active agent tested against Gram-positive organisms, including ciprofloxacin-susceptible strains and most ciprofloxacin- and methicillin-resistant staphylococci and enterococci. It was much more active than ciprofloxacin against streptococci, including Streptococcus pneumoniae and the viridans streptococci, and was also active against Bacillus cereus and Listeria monocytogenes, inhibiting all isolates at a concentration of <0.5 mg/L.

Phase I trial of uracil-tegafur (UFT) plus oral leucovorin: 14-day schedule.

We previously reported results of a Phase II trial of UFT [Taiho Pharmaceutical Ltd., Tokyo, Japan; (BMS-200604) Bristol-Myers Squibb, Princeton, NJ], an oral 4:1 molar concentration of uracil and tegafur, plus oral leucovorin for metastatic colorectal carcinoma (Pazdur et al., J. Clin. Oncol. 12:2296-2300, 1994]. Our results demonstrated that a 28-day schedule of this combination produced a response rate similar to that obtained with conventional intravenous fluorouracil (5-FU)-plus-leucovorin regimens but without the severe or life-threatening neutropenia or oral mucositis that complicates intravenous 5-FU regimens. The current Phase I trial examines the dose-limiting toxic effects and maximum tolerated dose of a 14-consecutive-day schedule of UFT plus oral leucovorin in 14 patients who had histologically proven cancer and had received prior chemotherapy. The daily UFT plus leucovorin dose was divided into three doses administered orally every 8 hours. In this study, the UFT dose was escalated while the leucovorin dose remained at 150 mg/day. Of the 14 patients, 4 were initially treated at the 350-mg/m2/day UFT level for 14 days without any dose-limiting toxic reactions. Subsequently, another 7 patients were treated at the 400-mg/m2/day level; grade 3 diarrhea developed in 3 of these 7 (with severe abdominal cramping in 2 cases and severe nausea and vomiting unresponsive to antiemetics in the third). To better define the starting dose for phase II studies, an additional 3 patients were treated at the 350-mg/m2/day dose level. Of the total 7 patients treated at 350 mg/m2/day, grade 3 toxic events (diarrhea) developed in 2 patients. Grade 1-2 toxic effects noted at this level included fatigue, stomatitis, skin rash, abdominal pain, nausea, and vomiting. Neither partial nor complete responses were observed in this trial. The maximum tolerated dose of this schedule is 350 mg/m2/day UFT plus 150 mg/day oral leucovorin. However, because of this schedule's inferior dose intensity compared with that of the 28-day schedule of UFT plus leucovorin, subsequent development of UFT in the United States has focused on the 28-day regimen.

Phase I trials of uracil-tegafur (UFT) using 5 and 28 day administration schedules: demonstration of schedule-dependent toxicities.

We conducted two consecutive phase I clinical trials to identify the qualitative and quantitative toxic effects of uracil-tegafur (UFT) [Taiho Pharmaceutical Co. Ltd, Tokyo, Japan; (BMS-200604) Bristol-Myers Squibb, Princeton, NJ] administered either on a 5 or 28 day schedule and to determine the phase II trial starting doses for both schedules. Nineteen patients were entered in the 5 day schedule and 23 patients were entered on the 28 day schedule; a minimum of three patients were entered at each dose level studied. In both phase I trials, the daily UFT dose was divided into three doses administered every 8 h. Dose levels examined with the 5 day schedule were 360, 720, 900 and subsequent de-escalation to 800 mg/m2/day. Dose levels studied with the 28 day schedule were 180, 360, 450 and subsequent de-escalation to 400 mg/m2/day. With the 5 day schedule, the dose-limiting toxicity (DLT) was granulocytopenia, with four of five patients experiencing grade 4 granulocytopenia at the 900 mg/m2/day dose level. With the 28 day schedule, the DLT was diarrhea, which was noted in three of eight patients treated at 400 mg/m2/day and in three of six patients treated at 450 mg/m2/day. At these dose levels, four of these patients required prolonged hospitalizations for their diarrhea. The toxic effects of UFT are schedule dependent, with marked differences in the toxic effect profile (neutropenia versus diarrhea). With the 5 day schedule, the phase II UFT starting dose is 800 mg/m2/day. On the 28 day schedule, the suggested phase II UFT starting dose is 360 mg/m2/day. Future clinical trials examining the combination the UFT plus oral folinic acid are being conducted to develop oral regimens of therapy for advanced colorectal carcinoma and adjuvant therapy for colon carcinoma.

Survey of antibiotic susceptibility among gram-negative bacilli at a cancer center.

A survey of the susceptibility of gram-negative bacilli isolated from cancer patients to broad-spectrum antimicrobial agents was conducted. The organisms were isolated from all patient specimens submitted to the microbiology laboratory during a 3-month study period. Overall, the least resistance was observed against cefoperazone/sulbactam, ciprofloxacin, and imipenem. Of these, cefoperazone/sulbactam has had limited usage at our institution. Drugs used more frequently (piperacillin, aztreonam, cefoperazone, ceftazidime) were associated with greater levels of resistance. Imipenem and ciprofloxacin have enjoyed wide usage but the level of resistance remains low.

In-vitro activity of ramoplanin (a novel lipoglycopeptide), vancomycin, and teicoplanin against gram-positive clinical isolates from cancer patients.

The in-vitro activities of ramoplanin, vancomycin, and teicoplanin against Gram-positive organisms isolated from cancer patients were determined. Ramoplanin was the most active agent tested inhibiting all isolates at a concentration of < or = 0.5 mg/L. Although all isolates were also susceptible to vancomycin and teicoplanin, their activities were surpassed by that of ramoplanin. The activity of teicoplanin was moderately better than that of vancomycin against Bacillus cereus, Enterococcus faecium, Listeria monocytogenes, methicillin-resistant Staphylococcus aureus, and most streptococcal isolates, and was comparable to vancomycin for the remainder of the isolates tested.

A phase I and pharmacokinetic study of oral uracil, ftorafur, and leucovorin in patients with advanced cancer.

A phase I and pharmacokinetics study of oral uracil, ftorafur, and leucovorin was performed in patients with advanced cancer. Uracil plus ftorafur (UFT) was given in a 4:1 molar ratio in three divided doses for 28 consecutive days. Patient cohorts were treated at 200, 250, 300, and 350 mg/m2 of UFT daily. For all patients, 150 mg of leucovorin was given daily in three oral doses. A 1-week rest period followed each 28-day treatment course. Gastrointestinal toxicity, characterized by diarrhea, nausea, and vomiting, was dose-limiting at 350 mg/m2 UFT in patients who had received prior chemotherapy. Mild fatigue and transient hyperbilirubinemia were also common. In previously untreated patients, UFT at 350 mg/m2 was well-tolerated, suggesting this as an acceptable phase II dose in this schedule with leucovorin. Two of eight previously untreated patients with advanced colorectal cancer had partial responses with UFT (350 mg/m2) plus leucovorin. Pharmacokinetic parameters [ftorafur, uracil, 5-fluorouracil (5-FU), 5-methyltetrahydrofolate] showed wide interpatient variations. Plasma levels of 5-FU (Cmax 1.4 +/- 1.9 microM) were comparable to those achieved with protracted venous infusions, and folate levels (Cmax 6.1 +/- 3.6 microM) were sufficient for biochemical modulation. Ongoing study will determine if this convenient oral regimen will compare favorably in terms of efficacy, toxicity, and cost with intravenous fluoropyrimidine programs.

Normocalcemic effect of gallium nitrate in a hypercalcemic rat model.

An established rat hypercalcemia model was used to study the effects of gallium nitrate on elevated serum calcium levels. Gallium nitrate was administered by i.v. or i.p. injection at daily doses of 0.07-0.45 mmol/kg for 5 days to the hypercalcemic rats beginning 1 day following surgery. A dose-correlated normocalcemic response was observed. Gallium nitrate administered late after the induction of the hypercalcemic state was also effective in reducing serum calcium levels. The p.o. administration, however, even at doses as high as 0.45 mmol/kg, did not reduce serum calcium to normal levels. The values of area under the concentration versus time curve (0-24 h) of gallium in normal rats were comparable after i.v. [49.2 (micrograms/ml)h] or i.p. [57.0 (micrograms/ml)h] injections. In contrast, the p.o. route achieved only 15% bioavailability, which may explain the ineffectiveness of p.o. administered gallium nitrate at that dose level. This study suggests that daily i.v. bolus injections of gallium nitrate for managing hypercalcemia may be potentially as effective as the current regimen of continuous i.v. infusion.

In vitro activity of FK-037, a novel parenteral cephalosporin, against bacterial isolates from neutropenic cancer patients.

The in vitro activity of FK-037, a novel parenteral cephalosporin, was compared to that of ceftazidime, aztreonam and piperacillin (agents often used in empiric regimens in cancer patients) against recent bacterial isolates from patients with cancer. FK-037 was either equal to or 2 to 16-fold more active than the comparative agents against members of the Enterobacteriaceae. It was also active against Acinetobacter spp., Aeromonas spp., Pseudomonas aeruginosa, and other Pseudomonas spp. Xanthomonas maltophilia and Alcaligenes denitrificans were relatively resistant to all four agents. FK-037 was also 4 to 16-fold more active against most gram-positive organisms (including some methicillin-resistant staphylococci) than was ceftazidime. Enterococcus spp., Listeria monocytogenes and Staphylococcus haemolyticus were relatively resistant to FK-037 and ceftazidime. Overall, FK-037 has a broad antimicrobial spectrum that includes the majority of gram-positive and gram-negative isolates.