Effects of treatment with FK409, a nitric oxide donor, on collar-induced intimal thickening and vascular reactivity.

Intimal thickening in arteries is considered a site of predilection for atherosclerosis. In a rabbit model of early atherosclerosis, a silastic collar was placed around the carotid artery, which resulted in the formation of intimal thickening. We investigated whether the oral application of FK409 ((+/-)-(E)-4-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexenamide , 10 mg kg(-1) day(-1), p.o.), a nitric oxide donor, inhibited the collar-induced intimal thickening as well as accompanying reactivity changes in rabbit carotid artery. The intimal thickening was significantly inhibited by FK409. The collar treatment increased the pD2 value of 5-hydroxytryptamine (5-HT) whereas it decreased those of phenylephrine and acetylcholine and did not significantly alter that of nitroglycerine. Maximal contractile force development in response to potassium chloride (KCl), 5-HT and phenylephrine was decreased in collared arteries. The collar did not alter the maximal relaxant effects of acetylcholine and nitroglycerine. Despite the significant reduction of intimal thickening, FK409 treatment did not affect these collar-induced modifications in vascular reactivity.

Urinary gamma-glutamyl transferase activity in rats with nonsteroidal anti-inflammatory drug-induced nephrotoxicity.

Excretion of urinary gamma-glutamyl transferase (GGT) was studied in rats following p.o. application of high doses (10 mg/kg/day) of indomethacin, diclofenac sodium or piroxicam for 28 days. Measurements of 24 h urinary GGT activity and urinary creatinine were carried out on 29th day. Histological examinations of kidneys were performed on day 29. The mean value for urinary GGT was found to be 0.77 +/- 0.05 U/mg creatinine (n = 16) in the control group. The mean activities in the treated groups were as follows: 1.30 +/- 0.15 U/mg creatinine (n = 17, indomethacin); 1.22 +/- 0.25 U/mg creatinine (n = 4, diclofenac); 1.54 +/- 0.39 U/mg creatinine (n = 5, piroxicam). The mean enzyme activities in indomethacin and piroxicam treated groups were significantly higher than in the control group (p < 0.02 and p < 0.03, respectively), while no significant difference has been found between the group treated with diclofenac and control group (p > 0.05). Histological examinations of renal tissues of indomethacin, piroxicam and diclofenac treated groups showed minimal glomerular abnormalities. Thus, determination of urinary GGT may be useful to investigate the nonsteroidal anti-inflammatory drugs (NSAIDs) related renal toxicity in rats.

Acute acetaminophen nephrotoxicity and urinary gamma-glutamyl transferase activity in rats.

In order to determine the relationship between the nephrotoxicity of acetaminophen and urinary gamma-glutamyl transferase (GGT) excretion, a single dose of 900 mg/kg acetaminophen (APAP) was administered to rats intraperitoneally. Following drug administration, 24 hour urine was collected and the kidneys were removed under ether anesthesia for histological examination. GGT activity measurements and quantitative analysis for creatinine was carried out on urine samples. Urinary GGT activity in the APAP administered group (n = 12) (1.88 +/- 0.21 U/mg creatinine) was significantly higher than in the control group (n = 16) (0.77 +/- 0.05 U/mg creatinine) (p < 0.0002). Histological examination of the kidneys under light microscopy showed only very slight tissue damage. Further use of urinary GGT activity measurements in experimental nephrotoxicity studies has been suggested.

Effect of verapamil on intimal thickening and vascular reactivity in the collared carotid artery of the rabbit.

1. Intimal thickening is a common site for atherosclerosis. Therefore, we investigated whether the calcium entry blocker verapamil (10 mg kg-1 body weight day-1, s.c.) can retard intimal thickening and changes in vascular reactivity induced by a non-occlusive, silicone collar positioned around the left carotid artery of rabbits. The contralateral carotid artery was sham-operated and served as a control. 2. Verapamil and placebo (saline 0.1 ml kg-1, day-1, s.c.) treatments were initiated 7 days before placing the collar and lasted 3 weeks. Thereafter, segments were cut from collared and sham-treated arteries for histology and isometric tension recording. 3. The intima/media (I/M ratio increased after 14 days of collar treatment, but intimal thickening was not inhibited by verapamil (I/M ratio placebo 0.31 +/- 0.07, verapamil 0.32 +/- 0.09). 4. The collar decreased the capacity to develop force, as indicated by the response to a supramaximal concentration of KCl, decreased the sensitivity (pD2) to acetylcholine (ACh) and phenylephrine (Phe), but increased the sensitivity to 5-hydroxytryamine (5-HT). 5. Although verapamil did not affect intimal thickening, it normalized the hypersensitivity to 5-HT in collared arteries. 6. The contraction to the supramaximal concentration of KCl was not affected by verapamil. Verapamil decreased the Emax of ACh, but this was only seen in collar-treated arteries. Verapamil also decreased the sensitivity to ACh and Phe, in both sham- and collar-treated arteries. 7. We conclude that verapamil, without preventing thickening of the intima, can modify collar-induced changes in vascular reactivity.

Study on the role of urine gamma-glutamyl transpeptidase activity during investigation of nephrotoxicity.

In this study, gamma-glutamyl transpeptidase activities of the 24 h urine samples taken at the end of the fourth day from the rats to which 160 mg/kg/day gentamicin was applied i.p. for 4 days, were measured. Glucose determination in urine by the use of the glucose hexokinase method was also applied in order to control the reabsorption potentials of the tubules. The formation of necrosis in the kidneys was investigated by histological examinations of the damage occurred by the nephrotoxic effect. All the results were compared with the values obtained from the control group. The average gamma-glutamyl transpeptidase activity for the control group (n = 22) was determined as 5.68 +/- 0.26 IU/24 h whereas this level was detected as 15.6 +/- 1.0 IU/24 h in the drug applied group (n = 15). The measurement of gamma-glutamyl transpeptidase activity in urine can be applied as a useful parameter on determination of nephrotoxicity, especially for indicating the dimensions of this toxic effect.

Antiinflammatory, analgesic, and antipyretic effects of an aqueous extract of Erythraea centaurium.

Erythraea centaurium is a plant which is used in the treatment of various inflammatory conditions in popular medicine. The aqueous extract of the plant has been examined for its antiinflammatory, analgesic, and antipyretic effects in several animal models. The extract exhibited antiinflammatory and antipyretic activity although no analgesic activity was observed.

The effect of cigarette smoke on the plasma piroxicam concentrations in rats.

The plasma concentration of unchanged piroxicam has been determined at 15, 30, 60 and 90 min after 10 mg kg-1 oral administration of the drug to rats exposed to cigarette smoke or pretreated with phenobarbitone, 3,4-benzpyrene or ethanol. Plasma piroxicam concentrations decreased in rats pretreated with phenobarbitone, 3,4-benzpyrene and ethanol and in rats 24 h after exposure to cigarette smoke.

The effect of a single treatment with cigarette smoke on the blood levels and hemodynamic effects of propranolol in rats.

The effect of a single treatment with cigarette smoke on the blood levels and hemodynamic effects of propranolol in rats was studied. Pentobarbital sleep time was not affected whereas zoxazolamine paralysis time was shortened 72% in rats, 24 h after the cigarette smoke exposure. The beta-adrenoceptor blocking effect of propranolol observed at 10 and 20 min time intervals was abolished in rats exposed to cigarette smoke 24 h after the exposure. The blood propranolol concentrations were decreased in rats pretreated with phenobarbital, 3,4-benzpyrene and ethanol as well as in cigarette smoke exposed rats. Among several factors that could influence propranolol metabolism, in this study, enzyme induction is suggested to be dominant.

Improved model for specimen classification based on single-cell classifiers.

We consider probabilistic models for specimen classification procedures based on systems which classify individual cells as normal or abnormal. The models which we consider generalize those discussed previously by Castleman and White (Anal. Quant. Cytol. 2:117-122, 1980; Cytometry 2:155-158, 1981) and by Timmers and Gelsema (Cytometry 6:22-25, 1985). In particular, they include the biologically plausible possibility that the specimen contains cells which are intermediate between the extremes of normal and abnormal. We find that if these additional cells occur differentially in normal and abnormal specimens, then specimen classification can become substantially more efficient when the cell classifier has different error rates for these cells.

Multidimensional slit-scan detection of bladder cancer. Preliminary clinical results.

A multidimensional slit-scan flow system was developed for the automated recognition of abnormal cells derived from cancer of the uterine cervix and its precursors. It provides great sensitivity in both its ability to recognize cellular abnormality and to deal with the myriad potential causes of false alarms in an automated flow system. While its initial application was the automated recognition of the spectrum of neoplasia in gynecologic cytology samples, a preliminary study was carried out using specimens obtained from the urinary bladder. Cellular material was collected by bladder irrigation and stained with the fluorochrome acridine orange. One hundred fifty-three bladder irrigation specimens, including 115 abnormal specimens containing cells derived from neoplastic lesions of the bladder epithelium, were analyzed. For the purposes of this study, abnormal specimens from the urinary bladder included specimens containing cells derived from the following lesions of the urothelium: dysplasia (atypical hyperplasia), carcinoma-in-situ, and transitional cell carcinoma, grades 1-3. Approximately 50,000 cells were analyzed for most specimens. Of the 38 presumed normal specimens (specimens containing only normal urothelial components), four were instrument classified abnormal. For the 69 specimens containing cells derived from transitional cell carcinoma, grade 1, 1-2, 2, 66 were correctly classified as abnormal while three were classified as normal.(ABSTRACT TRUNCATED AT 250 WORDS)

A statistical analysis of prescreening alarms in a population of normal and abnormal gynecologic specimens.

A multidimensional slit-scan flow system has been developed to serve as an automated prescreening instrument for gynecological cytology. Specimens are classified abnormal based on the number of cells having elevated nuclear fluorescence (alarms). An alarm region in a bivariate histogram of nuclear fluorescence versus nuclear-to-cell-diameter ratio is defined. Alarm region probability arrays are calculated to estimate the probability that an alarm falling in a particular bin of the alarm region is either from a normal or an abnormal specimen. From these arrays, a weighted alarm index is generated. In addition, summary indices are derived that measure how the distribution of alarms in each specimen compares with the average distributions for the normal and abnormal specimen populations. These indices together with current features are evaluated with respect to their utility in specimen classification using a nonparametric classification technique known as recursive partitioning. Resulting classification trees are presented that suggest information in the distribution of alarms in the bivariate histogram. In addition, they validate the features and rules currently used for specimen classification. Recursive partitioning appears to be useful for multivariate classification and is seen as a promising technique for other applications.

A protocol for Papanicolaou staining of cytologic specimens following flow analysis.

A protocol has been developed for restaining cytologic specimens that have been analyzed on a multidimensional slit-scan flow system. The technique involves Papanicolaou staining of cells on a membrane filter that has been previously stained with acridine orange and fixed with glutaraldehyde buffer. The specimen and staining solutions were sequentially added to a 5-micrometers pore size, 47-mm diameter Gelman "Metricel" filter while it remained in a glass filtration apparatus. The practice of retaining the filter in the filtration apparatus throughout the staining procedure minimizes cell loss and eliminates specimen cross contamination when compared with conventional filter dip staining. The availability of this postflow specimen Papanicolaou staining protocol permits accurate determination of the performance characteristics of a multidimensional slit-scan flow system and should be useful whenever staining of a limited number of cells with minimal cell loss is desired.

Multidimensional slit-scan prescreening system: preliminary results of a single blind clinical study.

A multidimensional slit-scan flow system was developed to serve as an automated prescreening instrument for gynecological cytology. A 2-year single blind clinical study was carried out to evaluate system performance. Cellular material was collected by scraping the uterine cervix and stained in suspension with acridine orange. Seven hundred and forty specimens (701 patients) including 156 abnormal specimens representing a broad spectrum of abnormality were analyzed. Approximately 50,000 cells were analyzed for each specimen. The system false-positive rate was 17.6% while the false-negative rate was 2.8%. All misclassified abnormals were specimens with cellular changes consistent with a slight dysplasia of nonkeratinizing type. The instrument in its present configuration appeared sensitive to the entire spectrum of abnormality existing in the female genital tract and it classified as abnormal any specimen containing on the order of 0.1% (or greater) abnormal cells.