The effect of dietary flavonoids on DNA damage (strand breaks and oxidised pyrimdines) and growth in human cells

The effects of the flavonoids quercetin, myricetin and silymarin on DNA damage and cytotoxicity in human cells were investigated. DNA strand breaks and oxidised pyrimidines were determined using alkaline single cell gel electrophoresis (the comet assay). Inhibition of cell growth was also measured. Caco-2 (colon), HepG2 (liver), HeLa (epithelial) cells and normal human lymphocytes showed different, dose-dependent susceptibilities (in terms of strand breakage) to the various flavonoids, quercetin being the most damaging. This agreed well with the ability of the flavonoids to inhibit cell growth. None of the flavonoids induced DNA base oxidation above background levels. All of the flavonoids under investigation caused depletion of reduced glutathione, which, in the case of quercetin, occurred prior to cell death. Neither cytotoxicity nor genotoxicity was associated with the antioxidant enzyme capacity (glutathione, glutathione reductase, glutathione peroxidase and catalase) of the cells.

Baker's cysts mimicking the symptoms of deep vein thrombosis: diagnosis with venous duplex scanning

PURPOSE

The purpose of this study was to determine the incidence and characteristics of Baker's cysts discovered during venous duplex examinations to rule out deep vein thrombosis (DVT).

METHODS

We reviewed the vascular laboratory charts of patients found to have Baker's cysts during venous duplex studies to rule out DVT from October 1988 through December 1995.

RESULTS

Ninety-five (3.1%) of 3072 patients who underwent venous duplex studies were found to have 111 Baker's cysts. Seven of the 95 had coexistent DVT. Ten patients had ruptured cysts, whereas six patients had cysts that compressed the popliteal vein.

CONCLUSION

The presentation of DVT and that of a Baker's cyst are similar enough to be difficult to distinguish by clinical examination. Careful examination of the popliteal fossa should be performed during venous duplex examinations regardless of the indication for the study.

Soldier performance and strenuous road marching: influence of load mass and load distribution

Fifteen male soldiers performed six maximal-effort, 20-km road marchers. They carried load masses of 34, 48, and 61 kg, using a standard military backpack with frame or an experimental doublepack. March times decreased as mass increased and were faster with the standard pack than with the double-pack. The doublepack resulted in less low back discomfort and a lower incidence of blisters at the highest load, but also resulted in more discomfort in the neck and hips. Neither load mass nor pack type affected soldiers' marksmanship ability, grenade throw accuracy, or cognitive ability. The maximal-effort march itself affected the marksmanship tasks by increasing the post-march vertical shot group dispersion. The concept of distributing the load mass more evenly around the center of mass of the body has both positive and negative aspects and warrants further investigation.

Cardiovascular effects of different infusion rates of sufentanil in patients undergoing coronary surgery

OBJECTIVE

Pharmacokinetics and haemodynamic effects of a total dose of 15 micrograms.kg-1 sufentanil, an opioid anaesthetic agent, were studied in patients undergoing aortocoronary bypass surgery at three infusion rates of 30 (group I), 5 (group II), and 2 (group III) micrograms.kg-1.min-1, respectively.

RESULTS

Plasma concentrations of sufentanil could be optimally characterized by a linear biexponential pharmacokinetic model. Non-compartmental analyses indicated that there was no significant difference in the values of clearance (11.6, 13.3, 14.3 ml.min-1.kg-1), steady-state volume of distribution (0.220, 0.255 and 0.331 l.kg-1) and mean residence time (18.8, 13.3 and 14.3 min) among the groups. The observed mean Cmax values of 421 (group I), 125 (group II), and 53 (group III) ng.ml-1 and observed mean AUC values from 0 to 3 min were all consistent with the dosing regimens. There were large inter-individual variations in haemo-dynamic response. Compared to plasma data, a delay in haemodynamic effects was found. Times to reach peak haemodynamic effect ranged from 4.3 to 4.9 min for group I, from 4.6 to 6.1 min for group II, and from 9.9 to 11.3 for group III. Except heart rate, peak haemodynamic effects in these study patients generally ranged from 20.9% to 35.2%. Significant reductions in the area under the effect-time profiles of mean arterial blood pressure and systemic vascular resistance were observed in group II and group III, but not in group I. Significant reductions in the area under the effect-time profiles of left ventricular stroke work index were observed in group III only. No effect on heart rate was found in any group.

CONCLUSION

Our findings suggested that a slower infusion rate of sufentanil at a dose of 15 micrograms.kg-1 tends to give a greater reduction in mean arterial blood pressure, systemic vascular resistance, and left ventricular stroke work index than does a faster infusion rate.

A coordinated high-performance liquid chromatographic, capillary electrophoretic, and mass spectrometric approach for the analysis of oligosaccharide mixtures derivatized with 2-aminoacridone

Glycans derivatized with 2-aminoacridone have been analyzed consecutively by reverse-phase high-performance liquid chromatography (HPLC) and micellar electrokinetic capillary chromatography (MECC). The 2-aminoacridone derivatizing agent used in the present study is highly hydrophobic and is well separated from the glycan derivatives in both separation techniques, ensuring that excess reagent does not interfere with the oligosaccharide analysis. The methodology outlined uses the high resolving power of capillary electrophoresis to determine the heterogeneity of samples after collection and preconcentration by HPLC. Collected glycan samples are submitted for mass spectrometric analysis to determine molecular weight. This methodology has been applied to linear oligosaccharides derived from dextran and to N-linked mannose-rich glycans from ribonuclease B.

Effects of caloric restriction on expression of testicular cytochrome P450 enzymes associated with the metabolic activation of carcinogens

Previous work demonstrated that microsomal cytochrome P4502A1 (CYP2A1) is expressed in rat testicular Leydig cells. The present study investigates the effects of diet, age, and strain on rat testicular CYP2A1 expression and assesses the potential role of testicular CYP2A1 in the metabolic activation of carcinogens. In ad libitum-fed 18-week-old Fischer 344 rats, testicular CYP2A1 immunoreactive protein and testosterone 7alpha-hydroxylase activity (7alpha-TOHase) exhibited a circadian variation with a daytime maximum and a night-time minimum (82.2 +/- 42.0 and 21.9 +/- 4.5 pmol 7alpha-hydroxytestosterone/min/mg protein, respectively). Caloric restriction (to 60% of ad libitum consumption), which reduces the severity of Leydig cell tumors in rats, decreased expression of both CYP2A1 and testicular 7alpha-TOHase >80% and eliminated their circadian variation. Conversely, caloric restriction induced a circadian rhythm in testicular 7-benzyloxyresorufin-O-dealkylase activity. Testicular microsomes from ad libitum-fed rats having peak diurnal 7alpha-TOHase activity had significantly greater (30%) microsome-mediated aflatoxin B1-DNA binding activity compared to microsomes prepared from nocturnal phase ad libitum-fed or calorically restricted rats which expressed low 7alpha-TOHase activity. In 12-month-old Fischer 344 rats, high CYP2A1 expression was correlated with severe Leydig cell hyperplasia (r = 0.80), whereas CYP2A immunoreactive protein and 7alpha-TOHase were expressed at lower levels in Sprague-Dawley than in Fischer 344 rats and were undetectable in pig, monkey, and human testes. These are strains/species that do not exhibit significant Leydig cell hyperplasia. This suggests that caloric intake, strain, and circadian factors may all mediate testicular CYP2A1 expression in the rat and that CYP2A1 may in turn influence carcinogen activation and pathological status in the testis.

Role of venous duplex scanning in patients with suspected pulmonary embolism

PURPOSE

We examined the use of venous duplex scanning (VDS) in the diagnosis of pulmonary embolism (PE) at our institution.

METHODS

Patients undergoing lower extremity VDS from October 1988 through June 1995 were cross-referenced with those who underwent ventilation perfusion (V/Q) scans and pulmonary angiography (PA) for PE.

RESULTS

A total of 664 of 3534 VDS were for "rule out PE." Deep venous thrombosis was found in 13%. A total of 256 VDS were in conjunction with V/Q scans in 249 patients, with only 8% undergoing PA. Deep venous thrombosis was present in 18% for those with both V/Q and VDS compared with 10% (p < 0.01) for those with VDS as the sole study. The order in which V/Q, VDS, and PA were obtained and the relationship of positive studies was examined.

CONCLUSION

We found no pattern to the sequence of tests ordered. V/Q scan rather than VDS should be the first study in the evaluation of PE. PE was diagnosed or excluded in nearly one third of patients based on V/Q as the initial study. A total of 29% of VDS could have been avoided. Treatment could be determined on the basis of VDS as the initial study in only 13%. We found only 14% incidence of positive PA in patients with nondiagnostic V/Q scans. We advocate judicious use of diagnostic tests in a stepwise fashion to appropriately treat patients with suspected PE.

Examination of external apical root resorption with scanning electron microscopy

External apical root resorption may be evident histologically but not visible radiographically until it is advanced. If working length is determined without considering this resorption, overinstrumentation or overfilling may occur.

OBJECTIVE

This study used scanning electron microscopy to examine the appearance and to compare the incidence of external apical root resorption in 40 teeth with differing pulpal and periapical diagnoses.

STUDY DESIGN

After extraction, 46 roots were sectioned horizontally 6 mm from the anatomic apex and prepared for scanning electron microscopy examination. Photomicrographs were scored by two blinded independent examiners. Apical resorption was categorized as: none, partial, or complete. Presence or absence of a funneling appearance of the resorption was also recorded.

RESULTS

Kruskal Wallis showed a significant difference in resorption between groups; teeth with irreversible pulpitis/normal periapex had the least resorption. Duncan's multiple range test found radiographic apical lesions to have more resorption than those without lesions; teeth with necrotic pulps had more resorption than those with vital pulps.

CONCLUSION

Pulp necrosis with radiolucent apical pathosis is more likely to demonstrate resorption.

Risk behavior and HIV seroincidence among out-of-treatment injection drug users: a four-year prospective study

We monitored trends in HIV risk behaviors and seroconversion among out-of-treatment injection drug users (IDUs) receiving street-based outreach intervention. Beginning in 1988, 641 HIV-seronegative IDUs were recruited by targeted sampling methods to reflect broader IDU populations and were followed for 4 years (1988-1992). All were active injectors not in treatment when recruited. Cohort members were targets of HIV-prevention outreach. The intervention was guided by the Indigenous Leader Outreach Model: Exaddicts deliver HIV-prevention services targeting IDU social networks in community settings. Primary outcome measures were HIV seroconversion and HIV risk behaviors. Observed incidence of HIV infection decreased, from 8.4 to 2.4 per 100 person-years. Prevalence of drug risk behaviors also decreased, from 100 to 14%. Seroconversion was associated with injection risk behavior [risk ratio (RR) = 9.8]. Sex risk behavior also decreased, but less dramatically, from 71 to 45%. Out-of-treatment IDUs in Chicago have reduced their rates of new HIV infection by reducing their injection risk behavior. New infections were strongly associated with injection risk behavior but not with sex risk behavior.

Pityriasis rubra pilaris with acantholysis

Two patients developed a papulosquamous eruption in a widespread distribution which progressed with islands of sparing of uninvolved skin characteristic clinically of adult-onset pityriasis rubra pilaris (PRP). Biopsies from both patients showed multiple areas of nonfollicular and follicular suprabasilar and intra-epidermal acantholysis with minimal dyskeratosis. They also showed the usual histologic features of PRP with a thickened orthokeratosis and parakeratosis, a retained and sometimes thickened granular cell layer, and psoriasiform epidermal hyperplasia with a perivascular lymphohistiocytic infiltrate in the superficial dermis. Two previous patients with PRP have been reported with nonfollicular, focal acantholytic dyskeratosis and both were interpreted as most likely representing an incidental finding. We believe the acantholysis in these two cases is related to the disease process, and in our second patient, was helpful in establishing the diagnosis.

Pulpal response to dentin etched with 10% phosphoric acid

PURPOSE

To histopathologically evaluate the effect of etching sound dentin with 10% phosphoric acid, in cavities prepared just within the DEJ on young patients.

MATERIALS AND METHODS

Twenty-four orthodontic patients who required premolar extractions were selected for the study. Each of the patients had facial Class V resin composite restorations placed in two maxillary premolars selected for extraction. Each preparation was cut circular, 2 mm in circumference and 0.5 mm into dentin. The dentin of one maxillary premolar preparation, randomly selected, was etched with 10% phosphoric acid (Bisco) for 20 seconds. This was followed by the placement of a dentin bonding agent (All-Bond 2) and a microfilled composite restoration (Silux). The contralateral maxillary premolar, received a similar preparation, but the dentin surface was lined with a light-cured glass ionomer liner before etching of the enamel, followed by placement of a dentin bonding agent and a microfilled resin composite restoration. One of the mandibular premolars was randomly selected as a negative control, having no treatment. Fourteen days after the placement of the restorations, the teeth were extracted, and histologically examined for insult to the pulpal tissues. Injury to the pulp was evaluated by quantitative measures of histopathology, including necrosis, infiltration by inflammatory cells, and other indicators of tissue injury.

RESULTS

Using a Kruskal-Wallis analysis, there was no statistically significant difference in pulpal histopathology of the teeth with etched dentin versus teeth with dentin protected by a liner or the negative control teeth (P < 0.05).

Laparoscopic fundoplication 1 month prior to lung transplantation

Upper midline laparotomy in the presence of pulmonary failure is often complicated by a prolonged period of mechanical ventilation postoperatively. We report the successful performance of laparoscopic fundoplication, without ventilatory support, in a woman with end stage pulmonary disease and resting hypercarbia, one month prior to lung transplantation.

Sequential test selection in the analysis of abdominal pain

Numerous decision-making tools exist to assist physicians in diagnosis management. However, the accuracy of available clinical information is often ambiguous or unknown and current analytical models do not explicitly incorporate judgementally defined information. A model encompassing both physician judgment and probability analysis was developed to accommodate such data. A problem requiring sequential diagnostic testing was structured utilizing the analytic hierarchy process (AHP). The case presented involved a patient complaining of upper abdominal pain who, after initial evaluation, did not need immediate surgery. Physicians were faced with identifying the optimal sequence of diagnostic testing. The criteria used for test selection included minimizing risk, patient discomfort, and cost of testing and maximizing diagnostic capability. Although at the onset the "best" test choice was unknown, the clinical picture indicated four test alternatives: upper gastrointestinal series (GI), abdominal ultrasonography (US), abdominal computed tomography (CT), and upper gastrointestinal endoscopy (END). Based upon the relative preferences of the criteria utilized, the AHP analysis indicated that upper GI series was the optimal first test. Given a negative test, posterior probabilities were calculated using Bayes' theorem, resulting in a new estimate of diagnostic capability. The AHP analysis was reiterated, identifying abdominal ultrasonography as the optimal second test. This analysis may be repeated as many times as necessary. Sensitivity analysis demonstrated that changing criteria preferences may alter the choice of tests and/or their sequence.

Construction and characterization of human chromosome 2-specific cosmid, fosmid, and PAC clone libraries

Three human chromosome 2-specific clone libraries were constructed and characterized. Chromosome 2-specific cosmid and fosmid clone libraries were constructed using flow-sorted DNA from the monochromosomal hybrid cell line GM10826. The cosmid and fosmid libraries consist of 38,496 and 26,400 arrayed clones, respectively, with an average size of 40 kb. Colony hybridization of a representative number of clones with both human and hamster genomic DNA probes demonstrates that between 58 and 66% of the clones in the flow-sorted libraries contain human inserts. Approximately 5% of the cosmid and fosmid clones are nonrecombinants. A chromosome 2-specific PAC library was also produced from the hybrid cell line GM10826. DNA from the hybrid cell line was cloned, and the human chromosome 2-specific clones were identified by colony hybridization. Approximately 5800 chromosome 2-specific PAC clones with an average insert size of approximately 85 kb were arrayed. Based on the size of the clones, the cosmid, fosmid, and PAC libraries are approximately 3.6x, approximately 2.5x, and approximately 1.9x, respectively in chromosomal coverage. The chromosome 2 coverage of each of the three libraries was further determined by PCR screening clone pools with 82 chromosome 2-specific STSs. The average number of clones identified for each STS in the library indicates the cosmid, fosmid, and PAC libraries to be approximately 3.2x, approximately 2.1x, and approximately 1.5x, respectively, in chromosome coverage. All except one of the 82 STSs were represented in the portions of the libraries screened.

Kinetic analysis of glutamate transport by the miniswine choroid plexus in vitro

Transport of glutamic acid by the choroid plexus, the blood-cerebrospinal fluid (CSF) barrier, was investigated by using the isolated choroid plexi from the fourth (FVCP) and lateral ventricles (LVCP) of the young adult miniswine in vitro. Glutamic acid uptake was very pronounced, with concentrations 7-fold (LVCP) and 2.4-fold (FVCP) higher in tissue than in medium after only 5 min of incubation with 1 microM glutamic acid. Tissue/medium ratios reached steady state by 15 min at 30-fold (LVCP) and 11-fold (FVCP). Uptake was energy-dependent and inhibited by ouabain and hypothermia. L-Aspartic acid was shown to be inhibitory in a concentration-dependent manner, suggesting that it shares a common transport system, whereas neither octanoic acid nor okadaic acid (transported by a separate fatty acid system) inhibited glutamic acid transport. At the same temperature, the labeled metabolite of glutamate (glutamine) in the tissue was 64.7%, 73.2%, and 72.5% of total radioactivity at 5, 30, and 60 min, respectively. The estimated Km values for glutamate uptake by the choroid plexus are 264 microM (FVCP) and 196 microM (LVCP); Vmax values are 87 (FVCP) and 147 (LVCP) nmol/g/min, respectively. These results indicate that, in addition to the metabolism of glutamate to glutamine, an active uptake mechanism is present in the choroid plexus of miniswine which may serve to regulate glutamic acid concentration in the CSF.

Interaction of Legionella pneumophila with Acanthamoeba castellanii: uptake by coiling phagocytosis and inhibition of phagosome-lysosome fusion

Legionella pneumophila is a facultative intracellular parasite able to survive within both human monocytes and amoebae. We have demonstrated that processing of L. pneumophila by the free-living amoeba Acanthamoeba castellanii shows many similarities to the processing of L. pneumophila by monocytes. These similarities include uptake of L. pneumophila by coiling phagocytosis and the subsequent confinement of L. pneumophila in a ribosome-studded phagosome. In addition, as in monocytes, inhibition of lysosomal fusion with phagosomes containing L. pneumophila was detected in amoebae. With all clinical isolates, inhibition of phagosomes-lysosome fusion correlated with virulence. However, with one of the environmental isolates tested, no significant difference in phagosome-lysosome fusion was observed between the virulent and avirulent forms. These results indicate that the avirulent form of this isolate differed from the virulent form in some other respect critical to intracellular survival. Therefore, intracellular multiplication of L. pneumophila within A. castellanii may not be solely dependent upon the inhibition of lysosomal fusion.

Acute cardiovascular effects of OPC-18790 in patients with congestive heart failure. Time- and dose-dependence analysis based on pressure-volume relations

BACKGROUND

OPC-18790 is a water-soluble quinolinone derivative that shares the pharmacological properties of vesnarinone and that may be useful for treating heart failure. We studied the contribution and relative dose sensitivities of the inotropic, lusitropic, and vascular effects of OPC-18790 in patients with dilated cardiomyopathy.

METHODS AND RESULTS

Pressure-volume (PV) analysis was performed in 17 patients who received either 5 micrograms.kg-1.min-1 (low dose, n = 10) or 10 micrograms.kg-1.min-1 (high dose, n = 7) OPC-18790 by 1-hour IV infusion. Right heart pressures and flow and left heart PV relations (conductance catheter) were measured at baseline and every 15 minutes during infusion. Transient inferior vena caval obstruction was used to determine PV relations. Both doses produced venodilation reflected by a 10% decline in left ventricular end-diastolic volume and a 30% fall in atrial and pulmonary artery pressures. Arterial dilation was four times greater at the high dose, with an approximately 40% fall in effective arterial elastance and systemic resistance. Contractility rose by 25% to 100% (depending on PV index) with both doses. Ventricular-arterial coupling (ratio of ventricular end-systolic to arterial elastances) was approximately 0.25 at baseline and doubled (or tripled) at low (or high) dose, correlating with improved efficiency. Isovolumetric relaxation shortened, whereas the diastolic PV relation was generally unchanged. Heart rate was unaltered.

CONCLUSIONS

OPC-18790 has potent venous and arterial vasodilator effects and moderate inotropic and lusitropic effects without a change in heart rate. These combined actions suggest a unique potential of OPC-18790 for heart failure treatment.

Evaluation of mass spectrometric methods applicable to the direct analysis of non-peptide bead-bound combinatorial libraries

Electrospray, matrix-assisted laser desorption, and time-of-flight secondary ion mass spectrometry have been explored as possible methods for the identification of active members of molecular combinatorial libraries. All three methods are found to yield accurate molecular weight information about a target molecule angiotensin II antagonist synthesized on a 40-microns polystyrene bead. Structural identification is also possible by accurate mass measurements to eliminate candidate structures with the same nominal mass and by analysis of the fragmentation patterns. In addition, the secondary ion mass spectrometry measurements yield spatially resolved spectra from a single bead after exposure to a suitable gas which clips the covalent bond at the linking position. All three approaches appear to offer a viable screening strategy of non-peptide libraries without the use of additional molecular tags.

Antibody-independent binding of complement component C1q by Legionella pneumophila

Incubation of Legionella pneumophila Philadelphia 1 in normal human serum depleted of either classical-pathway component C1q or alternative-pathway component factor B resulted in activation of the complement system. Experiments focused on the role of the classical pathway in complement activation revealed that legionellae bound C1q independently of antibody. Purified preparations of L. pneumophila major outer membrane protein but not serogroup 1 lipopolysaccharide bound C1q independently of antibody. This suggests that antibody-independent binding of C1q by L. pneumophila can result in activation of the classical pathway in normal human serum and that major outer membrane protein may be a C1q acceptor on the L. pneumophila cell surface.

Retrospective appraisals of fathers' effectiveness and psychological health of adults

Previous research has shown fathers' self-reports of their effectiveness to be positively correlated with their children's psychological health. To assess the relationship between adults' retrospective appraisals of fathers' effectiveness using a modified version of the Seven Secrets Survey and rated their current psychological health on the Personality Assessment Questionnaire. Total scores on the two measures correlated - .37. Three of the six Seven Secrets Survey scales, Knowing your Child, Consistency, and Protecting/Providing, were also correlated with total scores on the Personality Assessment Questionnaire.

Transvenous implantation of cardioverter defibrillators in the Electrophysiology Laboratory at CAMC

Since 1989, 78 patients have had Implantable Cardioverter Defibrillator (ICD) systems implanted in the Electrophysiology Laboratory (EPS) at the Charleston Area Medical Center. Between June 1993 and December 1994, 28 patients (21 males, 7 females) had new transvenous ICD systems successfully implanted in the Electrophysiology Laboratory. Coronary artery disease was present in 22 patients (76%). The mean left ventricular ejection fraction measured 28 percent (range 19%-45%), and the mean follow-up was 159 +/- 112 days (5.3 months). Twelve patients (43%) experienced shock, with an average of three per patient. The implantation of transvenous ICD systems in an electrophysiology laboratory is feasible, efficacious, safe, and associated with rapid patient recovery. With advances in technology, the procedure is becoming more comparable to a pacemaker implantation.

No evidence for association of familial Parkinson's disease with CAG repeat expansion

In some kindreds, familial Parkinson's disease (PD) exhibits genetic anticipation. Thus, we postulated that familial PD in certain kindreds may be associated with a CAG repeat expansion. However, using the repeat expansion detection method, we found no significant increase in the frequency of CAG repeat expansion among 46 unrelated PD probands compared with controls. Nor did we find evidence for CAG repeat expansion between generations in 11 different PD families that exhibit anticipation in age at onset.

Inhibition of collagen cross-linking: effects on fibrillar collagen and ventricular diastolic function

The fibrillar collagen network is postulated to be a primary determinant of left ventricular diastolic stiffness. This hypothesis was tested by examining the structural and physiological effects of a reduction in fibrillar collagen content and cross-linking in the intact left ventricle. Collagen cross-linking was inhibited by treating five normal adult pigs with beta-aminopropionitrile (BAPN; 10 g/day po) for 6 wk; five normal untreated pigs served as controls. Left ventricular volume, mass, and function were determined by simultaneous echocardiography and catheterization. Chamber stiffness, defined by pressure vs. volume data, and myocardial stiffness, defined by stress vs. dimension data, were determined from variably loaded beats during dextran infusion. Collagen distribution (% area) and integrity (% confluence) were determined by light microscopy. Collagen content was measured by hydroxyproline assay, and collagen cross-linking was measured by salt extraction. BAPN decreased collagen distribution (% area decreased from 12 +/- 1% in control to 7 +/- 1% in BAPN, P < 0.05), collagen integrity (% confluence decreased from 8 +/- 1% in control to 4 +/- 1% in BAPN, P < 0.05), collagen content (from 36 +/- 2 mg/g dry wt in control to 27 +/- 2 mg/g dry wt in BAPN, P < 0.05), and collagen cross-linking (extractable collagen increased from 21 +/- 2% in control to 28 +/- 2% in BAPN, P < 0.05). BAPN decreased chamber stiffness (0.13 +/- 0.02 in control to 0.06 +/- 0.01 in BAPN, P < 0.05) and myocardial stiffness (10.4 +/- 0.5 in control to 6.6 +/- 0.5 in BAPN, P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)