Pre-operative opening detrusor pressure is predictive of detrusor overactivity following TVT in patients with pre-operative mixed urinary incontinence

AIMS

To determine if specific pre-operative urodynamic parameters could predict detrusor overactivity following TVT in patients with urodynamic mixed incontinence.

METHODS

Notes of women with detrusor overactivity (DO) and urodynamic stress incontinence (USI) before undergoing tension-free vaginal tape (TVT) surgery were retrospectively reviewed. Patients underwent clinical evaluation pre-operatively including history, examination, and conventional urodynamic studies and were treated with pelvic floor exercises and anti-cholinergic medication. Those with persistent stress urinary incontinence (SUI) underwent TVT. Patients were re-assessed after at least 6 months post-operatively. Pre- and post-operative opening and closing detrusor pressure, and detrusor pressure at maximum flow were recorded retrospectively from pre-operative urodynamics traces by two clinicians independently and compared to the patients' post-operative symptoms and urodynamic diagnosis.

RESULTS

Fifty-one women were reviewed. Forty-six of the 51 attended follow-up and 35/51 agreed to conventional urodynamic studies. Seventeen of the 35 reported OAB symptoms, and 18/35 were asymptomatic. Nineteen of the 35 women had DO and 16/35 had normal urodynamic studies (NUDS). The median pre-operative opening detrusor pressure was higher in women with overactive bladder symptoms post-operatively. The median pre-operative opening detrusor pressure in women with DO post-operatively was 33.0 cmH(2)O and the median pre-operative opening detrusor pressure in those with NUDS post-operatively was 16 cmH(2)O (15.0-23.0 cmH(2)O) (P < 0.05 Mann-Whitney U-test).

CONCLUSIONS

Higher numbers of patients are required to demonstrate the value of opening detrusor pressure in predicting post-operative overactive bladder symptoms. Opening detrusor pressure is predictive of post-operative DO after TVT.

The treatment of urinary incontinence with Duloxetine

Duloxetine is a Serotonin and Noradrenaline reuptake inhibitor, and is the first drug licensed for medical treatment of urodynamic stress incontinence. In this paper, we will briefly review the pharmacology, current evidence and controversies in relation to the use of duloxetine.

Anti-atherogenic effects of seabuckthorn (Hippophaea rhamnoides) seed oil

Seabuckthorn (SBT) seed oil is a rich source of unsaturated fatty acids, phytosterols, carotenoids and flavonoids, which are known to have significant anti-atherogenic and cardioprotective activity. The anti-atherogenic activity of supercritical CO(2) extracted SBT seed oil was evaluated in white albino rabbits fed on high cholesterol diet for 60 days. The study was performed on 20 male healthy rabbits divided into four groups of 5 animals each. Group I - control, group II - SBT seed oil, group III - cholesterol (1%) for 60 days, group IV - cholesterol+SBT seed oil. After 30 days of high cholesterol diet, group IV rabbits received 1 ml of SBT seed oil daily for 30 days. Blood total cholesterol (TC), LDL-cholesterol (LDL-C), HDL-cholesterol (HDL-C) and triglyceride (TG) levels were measured before and after the administration of SBT seed oil. The vasorelaxant activity of the seed oil was studied in vitro using aortic ring model technique and changes in isometric force were recorded using a polygraphic recording system. Accumulation of cholesterol in the aorta was studied using Sudan-IV staining technique. SBT seed oil feeding to normal rabbits for 18 days caused a significant decline in plasma cholesterol, LDL-C, atherogenic index (AI) and LDL/HDL ratio. The HDL-C levels, HDL-C/TC ratio (HTR) and vasorelaxant activity of the aorta were significantly increased. In cholesterol-fed animals the TC, TG, LDL-C and AI were significantly increased and showed a decline following seed oil administration. The increase in HDL-C was more marked in seed oil treated hypercholesterolemic animals. The acetylcholine-induced vasorelaxant activity was significantly decreased in cholesterol-fed animals and could be restored to that of normal values by seed oil administration. These observations suggest that supercritical CO(2) extracted SBT seed oil has significant anti-atherogenic and cardioprotective activity.

Profile of pediatric dengue cases from a tertiary care hospital in Kolkata

A study was conducted on the 52 serologically positive cases of dengue, admitted to the Dept. of Paediatrics, R.G. Kar Medical College & Hospital, from an outbreak in Kolkata. The most unusual feature observed in this study was that the rash in some cases was urticarial and intensely pruritic. The shock appeared early in the course of the disease and it was less commonly associated with bleeding (22%). One out of three dengue cases was a severe disease. It was not possible to predict a severe disease from the early symptomatology.

The value of cystoscopy and bladder biopsy taken at the time of tension-free vaginal tape insertion

The primary aim of this study was to determine if a cystoscopy performed at the time of a tension-free vaginal tape (TVT) insertion is useful in finding unexpected pathology. A secondary outcome measure was to assess whether a bladder biopsy and cystoscopy performed during the TVT operation provide useful information about the outcome of surgery. The findings in 100 consecutive women were reviewed. A total of 42 women demonstrated mixed detrusor overactivity (DO) and urodynamic stress incontinence (USI); 32 women had abnormal biopsies. Women with DO were no more likely to have abnormal bladder biopsies than women without DO (p > 0.05). An abnormal bladder biopsy or cystoscopy failed to predict postoperative irritable symptoms (p > 0.05). The presence of preoperative DO correctly predicted postoperative irritable symptoms (p < 0.01). Cystoscopic abnormalities were noted in 14 women including one carcinoma, and one case of dysplasia was discovered on biopsy. In five women, the cystoscopy showed a bladder perforation. Cystoscopy should be performed in all women undergoing continence procedures.

Tolerability and efficacy of duloxetine in a nontrial situation

OBJECTIVE

To assess the tolerability and efficacy of duloxetine in a nontrial situation.

DESIGN

Prospective observational study.

SETTING

Urogynaecology Unit, District General Hospital, UK.

POPULATION

Two hundred and twenty-two women with a diagnosis of urodynamic stress incontinence (USI) or mixed USI and detrusor overactivity (DOA) took duloxetine for 4 weeks.

METHODS

The results of therapy were assessed with a Patient Global Impression of Improvement (PGI-I) questionnaire. One hundred and forty-eight (67%) women were initially treated with 40 mg twice a day, 67 (30%) women were treated with an escalating dose initially at 20 mg twice a day increasing to 40 mg twice a day after 2 weeks and seven (3%) women were started on a dose of 20 mg twice a day which they continued.

MAIN OUTCOME MEASURES

Discontinuation rates and PGI-I scores.

RESULTS

Overall 146/222 (66%) women discontinued therapy due to adverse effects or lack of efficacy. Significantly more women starting on the 40 mg twice a day dose stopped due to adverse effects when compared with the escalating dose (P < 0.025). Of the women who tolerated therapy, 80 out of 120 (67%) had a PGI-I score indicating an improvement. However, the overall rate of improvement was 37%. PGI-I scores and discontinuation rates were not significantly different between the group with USI and the group with mixed USI and DOA (P > 0.05).

CONCLUSION

In a nontrial situation duloxetine is poorly tolerated. Introducing an escalating dose may improve tolerability. A similar number of women with USI and mixed incontinence had a PGI-I score indicating improvement.

Dosimetry parameters of BARC OcuProsta I-125 seed source

A new model of 125I seed source, named OcuProsta seed, was designed and fabricated by Radiopharmaceuticals Division of Bhabha Atomic Research Centre for ophthalmic and interstitial applications. AAPM TG 43 recommended dosimetry parameters for this seed source were determined experimentally using TLD as well as by Monte Carlo (MC) simulation. Measured and MC calculated values of the dose rate constant (DRC) are 0.95 +/- 0.065 cGyh(-1)U(-1) and 0.972 +/- 0.005 cGyh(-1)U(-1), respectively. The mean of measured and calculated DRC (lambda = 0.96 cGyh(-1)U(-1)) was recommended for the clinical dosimetry of OcuProsta seed. Measured and MC calculated radial dose function, g(r), anisotropy function, F(r,theta), anisotropy factor and anisotropy constants are also found to be in good agreement to each other. Dosimetry parameters of OcuProsta seed were compared with the published values of similar in-design 125I seed sources. The DRC of BARC OcuProsta seed is very close to Amersham 6711 seed and is also comparable to the DRC of Best model 2301, Syncor PharmaSeed and Isotron selectSeed within the uncertainty of measurement/calculation. The g(r) of OcuProsta seed shows a difference of up to 10% in comparison to the g(r) values of the similar in-design seed sources. The values of anisotropy function of OcuProsta are 7-13% different from the anisotropy function of Amersham 6711 and Syncor PharmaSeed. The anisotropy constant of OcuProsta is close to Amersham 6711 seed while it is about 9% smaller than the anisotropy constant of Best model 2301 and Synchor PharmaSeed.

Bony fragments in the uterus: an association with secondary subfertility

Bone within the uterine cavity is an unusual finding in women with secondary subfertility, and is usually associated with a past history of termination of pregnancy. The etiology is unknown, but theories include retained fetal bone and osseous metaplasia of endometrial tissue. We describe the cases of three subfertility patients, all with a history of surgical termination of pregnancy. Each patient underwent a hysteroscopy after highly echogenic foci were seen in the uterus on transvaginal ultrasound examination. During hysteroscopy, several coral-like bony fragments were seen and removed by sharp curettage. On histological examination, these fragments were found to be mature, necrotic bone. This case report confirms the importance of routine baseline evaluation of the endometrium in subfertile women with a history of termination of pregnancy.

A new method of colorimetric assay of beta-lactamase suitable for estimation of beta-lactamase inhibition in crude microbial culture filtrates

A simple procedure is described for the rapid assay of beta-lactamases suitable for use in the quantitation of beta-lactamase inhibition in crude culture filtrates of soil microbes. The proposed method is based on measuring the blue reaction product (lambda max 750 nm) formed during reduction of phosphomolybdic acid with reducing products generated from beta-lactam hydrolysis and is not influenced significantly by the metabolites of microbial culture filtrates which often interfere with conventional beta-lactamase assay techniques.

Glucocorticoids as prophylaxis against acute mountain sickness

OBJECTIVE

Acute mountain sickness (AMS) characterized by presence of symptoms including headache, nausea, excessive fatigue, loss of appetite, irritability and insomnia is a major impediment to work performance in human subjects who are rapidly inducted to high altitude (HA) during the initial phase of induction. The present study aims at to evaluate the efficacy of prophylactic administration of low dose glucocorticoids in prevention of AMS in normal healthy men who are inducted to HA by air.

DESIGN

Fifty healthy men were randomly divided into five groups of 10 each. Group I received prednisolone (Pred) 10 mg, Group II Pred 20 mg, Group III Pred 40 mg, Group IV dexamethasone 0.5 mg, Group V received placebo once a day in the morning for 2 days at sea level (SL) and for 3 days on arrival at an altitude of 3450 m by air.

MEASUREMENTS

The severity of AMS was assessed using Lake Louise AMS scoring system. Physiological parameters like blood pressure, respiratory rate, peripheral blood O2 saturation and heart rate were measured at sea level and on arrival at HA. Circulatory levels of cortisol and adrenocorticotropic hormone (ACTH) were measured by radioimmunoassay (RIA) and immunoradiometreic assay (IRMA), respectively.

RESULTS

In the placebo group, significant AMS could be detected at 12 h of arrival at HA, peaked by day 1 or 2 of stay and started declining thereafter. As compared to the placebo group, the steroid treated groups showed a significant (P < 0.01) reduction in daily AMS score. When compared with prednisolone 10 mg, 40 mg and dexamethasone groups, the prednisolone 20 mg group showed an optimal response in reduction of AMS symptoms. The O2 saturation showed a significant decline (P < 0.001) on arrival at HA, but the pattern of O2 saturation in placebo and glucocorticoid groups was identical. Similarly, the rise in heart rate and blood pressure and on day 3 of stay at HA was similar in placebo and glucocorticoid-treated groups. An increase in plasma cortisol in placebo group was observed on day 3 of stay at HA and continued to rise till day 8 of observations. The cortisol levels in Pred 10 mg and Pred 20 mg groups on day 1 and 3 of arrival at HA were not significantly different than the SL post-treatment values but were found to be significantly higher on day 8 of stay. Plasma cortisol in Pred 40 mg and dexamethasone groups was significantly lower (P < 0.01) on day 1 and 3 of stay but showed an increase by day 8 of stay. The ACTH levels were increased at HA in placebo group but did not show any significant change till day 3 of stay in steroid treated subjects and were found to be higher in all groups on day 8 of observations.

CONCLUSION

These observations suggest that administration of low-dose glucocorticoids can curtail acute mountain sickness significantly without influencing the normal adreno cortical response to hypoxia.

Hypothalamic-pituitary-adrenal axis following glucocorticoid prophylaxis against acute mountain sickness

The pituitary-adrenocortical and adrenomedullary response to high altitude (HA) stress was studied following daily single dose administration of prednisolone as a prophylaxis against altitude-induced acute mountain sickness (AMS). Forty healthy men, randomly divided into two groups of twenty, received placebo or prednisolone 20 mg once a day at 08.00 h for two days prior to induction to HA and during an initial three days stay at an altitude of 3450 m. The AMS score and circulatory levels of ACTH, cortisol, epinephrine and norepinephrine were measured at sea level (SL) and during residency at HA. The sensitivity of the hypothalamic-pituitary-adrenal axis in subjects receiving prednisolone therapy was evaluated at SL and on day four of stay at HA. Administration of prednisolone significantly (p < 0.01) decreased the severity of AMS in all the subjects. The steroid dose used did not inhibit endogenous secretion of ACTH, cortisol, epinephrine or norepinephrine, as HA response to adrenocortical and adrenomedullary hormones was identical in placebo and prednisolone treated subjects. The integrity of the hypothalamic-pituitary-adrenal axis was maintained well in subjects receiving low dose prednisolone therapy. These observations suggest that short-term administration of prednisolone is able to curtail AMS without causing suppression of the hypothalamic-pituitary-adrenal axis.

Mechanisms of hormonal carcinogenesis in the p53+/- hemizygous knockout mouse: studies with diethylstilbestrol

The 2-year rodent bioassay has long had a central role in determining whether a compound is carcinogenic. It has recently been suggested that the use of 6-month studies in transgenic mice could reduce costs and animal numbers, without impairing the validity of cancer risk assessment. The p53+/- hemizygous knockout mouse model is phenotypically stable and develops tumors during the 6-month study period only in response to chemical and physical stimuli, showing a high concordance with genotoxic rodent carcinogens. We treated p53+/- mice and wild-type parent strain (C57BL/6J) animals with diethylstilbestrol (DES). 500 micromol/kg i.p. for 4 days. Following sacrifice, DNA was extracted from various tissues and adducts measured by a modified monophosphate version of the 32P-postlabelling assay. Major DES adducts were detected in the liver DNA of DES-treated wild-type mice at a level of 118.7+/-17.0 (mean +/- SD relative adduct level [RAL]/10(10) nucleotides) compared with 207.7+/-36.4 in p53+/- mice. No such adducts were detected in vehicle-treated animals. Total adduct levels, including endogenous I-compound adducts, in wild-type mice were 192.4+/-17.5 and 311.5+/-58.6 in p53+/- animals. These data support the hypothesis that deficient p53-dependent global genomic repair of DES adducts in p53+/- mice may result in the persistence of exogenous and endogenous DNA adducts that could contribute to earlier carcinogenicity in this model. We also prepared hepatic microsomes from male and female p53+/- and wild-type mice exposed to DES or vehicle. Western blot analysis demonstrated modestly higher basal levels of various cytochrome P450 (CYP) enzymes in the untreated p53+/- mice compared to the wild-type mice. Furthermore, P450 levels were higher in female DES-treated p53+/- mice compared to treated wild-type mice. For the p53+/- knockout mice to be used with contidence in drug safety studies, a further understanding of the metabolic capacity of these animals is needed.

Effect of selenomethionine on N-methylnitronitrosoguanidine-induced colonic aberrant crypt foci in rats

An association between low selenium intake and the incidence or prevalence of cancers is well known. Selenium in the form of selenomethionine supplemented in drinking water has been found to be highly effective in reducing tumour incidence and preneoplastic foci during the development of hepatocarcinogenesis in rats in our previous studies. Here, an attempt has been made to investigate whether the dose and form of selenium found to be effective during hepatocarcinogenesis is equally effective in N-methylnitronitrosoguanidine-induced colorectal carcinogenesis in terms of antioxidant defence enzyme systems, DNA chain breaks and incidences of aberrant crypt foci. Treatment with selenomethionine either on initiation or on selection/promotion, or during the entire experiment showed that selenomethionine was most effective in regulating the cellular antioxidant defence systems, DNA chain break control and reducing aberrant crypt foci in the colorectal tissues of rats. Our results also confirm that selenium is particularly effective in limiting the action of the carcinogen during the initiation phase of this colorectal carcinogenesis, just as we found with hepatocarcinogenesis in our previous studies.

Functional mapping of protective domains and epitopes in the rotavirus VP6 protein

The purpose of this study was to determine which regions of the VP6 protein of the murine rotavirus strain EDIM are able to elicit protection against rotavirus shedding in the adult mouse model following intranasal (i.n.) immunization with fragments of VP6 and a subsequent oral EDIM challenge. In the initial experiment, the first (fragment AB), middle (BC), or last (CD) part of VP6 that was genetically fused to maltose-binding protein (MBP) and expressed in Escherichia coli was examined. Mice (BALB/c) immunized with two 9-microg doses of each of the chimeras and 10 microg of the mucosal adjuvant LT(R192G) were found to be protected against EDIM shedding (80, 92, and nearly 100% reduction, respectively; P </= 0.01) following challenge. Because CD produced almost complete protection, we prepared four E. coli-expressed, MBP-fused chimeras containing overlapping fragments of the CD region (i.e., CD1, CD2, CD3, and CD4) whose lengths ranged from 61 to 67 amino acid residues. Following i.n. immunization, CD1, CD2, and CD4 induced significant (P </= 0.004) protection (88, 84, and 92% reduction, respectively). In addition, 11 peptides (18 to 30 residues) of the CD region with between 0 and 13 overlapping amino acids were synthesized. Two 50-microg doses of each peptide with LT(R192G) were administered i.n. to BALB/c mice. Five peptides were found to elicit significant (P </= 0.02) protection. Moreover, a 14-amino-acid region within peptide 6 containing a putative CD4(+) T-cell epitope was found to confer nearly complete protection, suggesting a protective role for CD4(+) T cells. Mice that were protected by fragments BC and CD1 and four of the five protective synthetic peptides did not develop measurable rotavirus antibodies in serum or stool, implying that protection induced by these domains was not dependent on antibody. Together, these observations suggest that multiple regions of VP6 can stimulate protection, a region of VP6 as small as 14 amino acids containing a CD4(+) T-cell epitope can stimulate nearly complete protection, and protection mediated by a subset of epitopes in the VP6 protein does not require antibodies in BALB/c mice.

Vanadium chemoprevention of 7,12-dimethylbenz(a)anthracene-induced rat mammary carcinogenesis: probable involvement of representative hepatic phase I and II xenobiotic metabolizing enzymes

Vanadium, a non-platinum group metal and dietary micronutrient, is now proving to act as a promising antitumor agent. The present study was conducted to ascertain its antineoplastic potential against an experimental mammary carcinogenesis. Female Sprague-Dawley rats, at 50 days of age, were treated with 7,12-dimethylbenz(a)anthracene (DMBA) (0.5 mg/100 g body weight) by a single tail vein injection in an oil emulsion. Vanadium (ammonium monovanadate) at the concentration of 0.5 ppm was supplemented in drinking water and given ad libitum to the experimental group immediately after the carcinogen treatment and it continued until the termination of the study (24 weeks for histological and biochemical observations and 35 weeks for morphological findings). It was found that vanadium treatment brought about a substantial protection against DMBA-induced mammary carcinogenesis. This was evident from histological findings that showed no sign of hyperplasia or abnormality after vanadium treatment. There was a significant reduction in incidence (P < 0.05), total number, multiplicity (P < 0.01) and size of palpable mammary tumors and delay in mean latency period of tumor appearance (P < 0.001) following vanadium supplementation compared to DMBA control. From the cumulative results of various hepatic biochemical indices namely, lipid peroxidation, reduced glutathione level, superoxide dismutase activity, cytochrome P450 content and glutathione S-transferase activity, the anticarcinogenic potential of vanadium was well reflected through stabilization of these parameters. Results of the study indicate that the anticarcinogenic activity of vanadium during DMBA-initiated mammary carcinogenesis is mediated through alteration of hepatic antioxidant status as well as modulation of phase I and II drug metabolizing enzymes. On the basis of the observed results, vanadium can be considered as a readily available, promising and novel cancer chemopreventive agent.

Combined supplementation of vanadium and 1alpha,25-dihydroxyvitamin D(3) inhibit diethylnitrosamine-induced rat liver carcinogenesis

A combination of a differentiation-inducing agent like 1alpha, 25-dihydroxyvitamin D(3) [1,25(OH)(2)D(3)] with a compound that blocks entry of calcium into cells like vanadium (V) may offer a new approach to differentiation therapy and address the problem of hypercalcemia. Initiation of hepatocarcinogenesis was performed by a single intraperitoneal injection of diethylnitrosamine (DEN) (200 mg/kg b.wt.) in male Sprague-Dawley rats. Supplementation of V, 1, 25(OH)(2)D(3), or both V and 1,25(OH)(2)D(3) were started 4 weeks prior to DEN injection and continued thereafter till 20th week. It was observed that supplementation of V (0.5 ppm) in drinking water ad libitum or 1,25(OH)(2)D(3) (3 microg/ml propylene glycol) per os twice weekly for the entire period of the experiment significantly reduces the number and size of hyperplastic nodules while the combination treatment offered an additive effect in reducing it to 37.5% from 83.3%. V-1,25(OH)(2)D(3) combination was also effective in elevating the level of hepatic microsomal cytochrome P-450 (Cyt. P-450) (P<0.001). Moreover, A significant reduced level of cytosolic glutathione (GSH) (P<0.001) and glutathione S-transferase (GST) (P<0.001) activity as well as reduction in the appearance of gamma-glutamyltranspeptidase (GGT)-positive foci (P<0.001) as compared to carcinogen control were observed in V plus 1, 25(OH)(2)D(3) treated group. These results suggest that V may be useful in combination with 1,25(OH)(2)D(3) in the inhibition of experimental rat hepatocarcinogenesis.

Factors on the third chromosome affect the level of cyp6a2 and cyp6a8 expression in Drosophila melanogaster

The expression of two second chromosome-linked cytochrome P450 genes, Cyp6a2 and Cyp6a8, of Drosophila melanogaster was measured in various strains. Six different strains, including ry(506) and 91-C, showed low or undetectable levels of CYP6A2 and CYP6A8 mRNAs, suggesting that low expression is the wild-type phenotype of Cyp6a2 and Cyp6a8 genes. In the 91-R and MHIII-D23 strains, however, both these genes are overexpressed. In order to examine the genetic basis of Cyp6a2 and Cyp6a8 expression, CYP6A2 and CYP6A8 RNA levels were measured in the F1 hybrids of overproducer (91-R and MHIII-D23) and underproducer (ry(506) and 91-C) strains. Results showed that the total amounts of CYP6A2 and CYP6A8 mRNAs in the F1 hybrids were lower than half the amounts of these RNAs found in the overproducer parental strains. This suggested that the underproducer strains carry loci which downregulate Cyp6a2 and Cyp6a8 gene expression. To determine the chromosome linkage of these loci, several stocks homozygous for the second chromosome of overproducer 91-R strain and, therefore, homozygous for the Cyp6a2-91R and Cyp6a8-91R alleles were synthesized. The third chromosomes in all these stocks were from the underproducer ry(506) strain. The levels of expression of both Cyp6a2-91R and Cyp6a8-91R genes in these three stocks were significantly lower than that observed in the 91-R strain. One of these stocks, named iso-2, showing reduced expression, was used to synthesize two new isogenic stocks by resubstituting the third chromosome of ry(506) origin with third chromosomes of the 91-R strain. Expression of both Cyp6a2-91R and Cyp6a8-91R alleles was found to be much higher in these two resubstituted isogenic stocks than in the progenitor iso-2 stock. Taken together, these results suggest that the second chromosome-linked Cyp6a2 and Cypa8 genes are regulated by loci present on the third chromosome, and the wild-type function of these loci is to repress these two Cyp genes. The data also suggest that Cyp6a2 and Cyp6a8 overexpression in the 91-R and MHIII-D23 strains is more likely due to mutation in the repressor locus (or loci) rather than in the cis-regulatory sequences of the Cyp6a2 and Cyp6a8 genes.

Beta-carotene prolongs survival, decreases lipid peroxidation and enhances glutathione status in transplantable murine lymphoma

Carotenoids of dietary origin have recently been the subject of renewed research interest because of epidemiological evidence indicating an inverse relationship between intake of carotenoids-rich plant substances and risk of certain cancers. This study was attempted to understand the biological actions of dietary beta-carotene (BC) on Dalton's lymphoma (DL), a rapidly proliferating transplantable tumor, in effecting the survival of the lymphoma-bearing mice. The glutathione (GSH) level and the extent of lipid peroxidation in the liver, kidney and brain were monitored in BC-treated (100 mg/kg food) mice transplanted with DL. These markers showed substantial alterations during the whole length of tumor progression in lymphoma-bearing mice without BC supplementation. When treated with BC, both malondialdehyde contents (evidence of lipid peroxidation) and the GSH levels in different organs were found to be closer to normal values in the initial period of tumor progression. BC-mediated protection against lipid peroxidation was maximally found to be in hepatic tissue throughout the study following DL transplantation. This was fairly reflected in the higher BC concentration in hepatic tissue of BC-treated lymphoma group compared to untreated lymphoma control. Significantly higher survival time (51-55 days) was observed in BC-treated animals in comparison to their untreated DL counterparts (35-38 days). The prolonged survival observed in the BC-supplemented animals may be attributed to the higher resistance offered by animals receiving BC towards lipid peroxidation-related tissue injury.