Change of Hemoglobin Level among Exclusively Breastfed Term and Preterm Babies up to Six Months of Age.

There is progressive increase of Hb levels is observed during course of intrauterine development of fetus but high concentrations found at birth. In preterm neonate normal Hb is characteristically deviated from term neonate. Breast milk is the only natural ideal food for both term and preterm babies from birth up to 6 months. Preterm milk was found to contain significantly higher concentrations nutrients particularly iron than term milk. Preterm human milk is more suitable for the premature infant than term human milk. As Hb concentration varies in term and preterm babies in different counties in different feeding practices. The purpose of this longitudinal descriptive study is to find out the pattern of changes in the Hb level among exclusively breastfed preterm and term infants during the first six months of life. This study was carried in the Neonatal Intensive Care Unit (NICU), Mymensingh Medical College Hospital (MMCH), Mymensingh from September 2016 to February 2018. One hundred fifty (150) neonates both term and preterm were included in this study and followed up to 6 months of age. After admission informed written consent was taken from parents, thorough history taking and clinical examination were done. Data were collected in a pre-designed case record form. All the babies of Group A provided 2mg/kg iron supplementation from 6 weeks for 2 months for universal recommendation. Hb level was measured of all exclusively breast feed babies at admission after birth then next follow-up at 6 weeks, 3 months and 6 months. All information regarding history, anthropometrics measurement, Hb level was recorded in structural questionnaire. Data analysis was done by SPSS version 20.0. Male were predominant in both groups. Most of the preterm (72.0%) and term babies (65.3%) were delivered by vaginal route. Mean Hb level was found significantly higher among preterm babies than term babies after birth were 16.55g/dl and 15.98g/dl respectively. Sharp fall of Hb concentration was observed after birth up to 6 weeks in both preterm and term babies but Hb level was found significantly lower in preterm in comparison to term babies (9.27gm/dl vs. 9.58gm/dl). In term babies, even after 6 weeks fall of Hb level continued to 3 months of age followed by gradual increase up to 6 months without iron supplementation. Hb level of in preterm babies gradually increased from 6 weeks up to 6 months with universal iron supplementation. Hb level fall sharply up to 6 weeks in both exclusively breastfed term and preterm babies but even after 6 weeks term babies experienced gradual fall of Hb levels up to 3 months. Hb level increases in exclusively breast-fed term babies without iron supplementation from 3 months of age. Hb level in exclusively breastfed preterm babies increase from 6 weeks onward might be effect of universal iron supplementation.

Diagnostic and Management Strategies for Patients with Chronic Prostatitis and Chronic Pelvic Pain Syndrome.

Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is a common and often heterogenous condition that can have severe consequences on patient quality of life. In this review, we describe the pathophysiology, diagnostic work-up, and treatment of patients with CP/CPPS incorporating the most recent literature. Studies have demonstrated that CP/CPPS involves a complex pathophysiology, including infectious, immunologic, neurologic, endocrinologic, and psychologic etiologies, with frequent intersections between the different entities. Despite robust research assessing a variety of therapeutics targeting these etiologies, clinical trials have failed to identify an empiric treatment strategy applicable specifically to older adult male patients with CP/CPPS. As such, it can be challenging to manage older male patients with this condition. The advent of clinical phenotyping of patients with CP/CPPS has led to advances in tailored management strategies. Monomodal therapy has been largely unsuccessful because of the unclear and complex etiology of CPPS. As a result, CP/CPPS therapy has transitioned to a multimodal approach, including both pharmacologic and non-pharmacologic therapies. The best studied pharmacologic therapies include antibiotics, alpha-blockers, anti-inflammatory and immunomodulatory agents, phytotherapies, phosphodiesterase inhibitors, hormonal agents, neuromodulatory agents, and antidepressants. The best studied non-pharmacological therapies include pelvic floor physical therapy, myofascial trigger point release, acupuncture and electroacupuncture, psychological support and biofeedback, and electrocorporeal shockwave therapy and local thermotherapy.

Effect of Finishing Procedures on the Surface Roughness of Resin-modified Glass-Ionomer Materials.

This study examined the influence of finishing procedures on the surface roughness of different formulations of resin-modified glass ionomers (RMGIs) available in capsules compared with standard resin composites (RCs). Disc samples of three RMGIs and two RCs were fabricated using a metal mold (5 mm x 1.5 mm). Samples were randomly divided into seven groups (N = 10) and subjected to finishing and polishing procedures using a combination of carbide or diamond burs, followed by either rubber points or aluminum-oxide discs. Three different regions of each sample were analyzed using a contact profilometer to determine the average roughness (Ra). The main surface roughness was calculated using a two-way analysis of variance (ANOVA) and the Bonferroni correction for multiple comparisons. A dual-stage combination of a fine carbide bur followed by the use of the finest two grits of aluminum-oxide discs was found to produce the smoothest finished and polished surface. the smoothest surfaces were found to be on the two RCs and one of the RMGIs.

Cell-Free Protein Synthesis Approach to Biosensing hTRß-Specific Endocrine Disruptors.

Here we introduce a Rapid Adaptable Portable In vitro Detection biosensor platform (RAPID) for detecting ligands that interact with nuclear hormone receptors (NHRs). The RAPID platform can be adapted for field use, allowing rapid evaluation of endocrine disrupting chemicals (EDCs) presence or absence in environmental samples, and can also be applied for drug screening. The biosensor is based on an engineered, allosterically activated fusion protein, which contains the ligand binding domain from a target NHR (human thyroid receptor ß in this work). In vitro expression of this protein using cell-free protein synthesis (CFPS) technology in the presence of an EDC leads to activation of a reporter enzyme, reported through a straightforward colorimetric assay output. In this work, we demonstrate the potential of this biosensor platform to be used in a portable "just-add-sample" format for near real-time detection. We also demonstrate the robust nature of the cell-free protein synthesis component in the presence of a variety of environmental and human samples, including sewage, blood, and urine. The presented RAPID biosensor platform is significantly faster and less labor intensive than commonly available technologies, making it a promising tool for detecting environmental EDC contamination and screening potential NHR-targeted pharmaceuticals.

Effect of Topical Anesthesia with Lidocaine-prilocaine (EMLA) Cream and Local Pressure on Pain during Infiltration Injection for Maxillary Canines: A Randomized Double-blind clinical trial.

OBJECTIVES: This study compared the effect of local pressure and topical lidocaine-prilocaine (EMLA) cream on pain during infiltration injection for maxillary canine teeth. MATERIALS AND METHODS: A total of 140 volunteer students participated in this split-mouth design randomized clinical trial. The subjects were randomly divided into four groups (n = 35). Before administration of anesthesia, in each group, one side was randomly selected as the experimental and the opposite side as the control. In group 1, finger pressure was applied on the alveolar mucosa on the experimental side and on the tooth crown on the control side. In group 2, 5% EMLA cream and placebo; in group 3, finger pressure and 5% EMLA cream; and in group 4, 5% EMLA cream and 20% benzocaine gel were applied. In all the groups, a buccal infiltration procedure was carried out. Pain during injection was recorded with visual analog scale (VAS). Wilcoxon and McNemar tests were used for statistical analysis of the results. Statistical significance was set at p < 0.05. RESULTS: The results showed that EMLA reduced the injection pain significantly more than benzocaine (p = 0.02). Also, injection pain was significantly lower with the use of EMLA in comparison to placebo (p = 0.00). Application of local pressure reduced the injection pain, but the difference from the control side was not significant (p = 0.05). Furthermore, the difference between application of local pressure and EMLA was not statistically significant (p = 0.08). CONCLUSION: Topical anesthesia of 5% EMLA was more effective than 20% benzocaine in reducing pain severity during infiltration injection. However, it was not significantly different in comparison to the application of local pressure.

Effects of foods and beverages on the symptoms of chronic prostatitis/chronic pelvic pain syndrome.

OBJECTIVE: To better elucidate the prevalence of perceived food sensitivity and characterize the sensitivity pattern in patients with clinically diagnosed chronic prostatitis/chronic pelvic pain syndrome. METHODS: A total of 286 men meeting the National Institutes of Health criteria for chronic prostatitis were mailed a validated questionnaire designed to detect the effect of foods, beverages, and/or supplements on pelvic pain symptoms. The questionnaire assessed the effect of 176 individual comestibles on each patient's symptoms. The responses were numerically scored on a scale of -2 to +2, and the mean values were generated for each comestible. In addition, the participants were asked to complete the O'Leary-Sant Symptom and Problem Index and Chronic Prostatitis Symptom Index questionnaires. RESULTS: Of the 286 surveys, 95 were returned, yielding a response rate of 33.2%. Of those subjects who responded, 47.4% reported that the consumption of certain comestibles aggravated their symptoms, with the most aggravating being spicy foods, coffee, hot peppers, alcoholic beverages, tea, and chili. In contrast, the comestibles that alleviated the symptoms the most included docusate, pysllium, water, herbal teas, and polycarbophil. CONCLUSION: Many patients with chronic prostatitis/chronic pelvic pain syndrome have demonstrable food, beverage, and dietary supplement sensitivities. Dietary changes should be considered in the treatment of these patients.

Alternative therapies in the management of chronic prostatitis/chronic pelvic pain syndrome.

PURPOSE: Standard medical therapy for Chronic Prostatitis/Chronic Pelvic Pain Syndrome (CP/CPPS) including such agents as nonsteriodal anti-inflammatories, alpha-blockers, antimicrobial therapy, and 5a-reductase inhibitors has not been uniformly effective. The purpose of this review is to focus on the role of alternative therapies available for the management of CP/CPPS. METHODS: We performed a systematic review of the literature for articles published in PubMed up to 2012 pertaining to commonly employed alternative therapies. RESULTS: The evidence for alternative therapies such as diet and lifestyle modifications, phytotherapy, acupuncture, myofascial physical therapy, and stress management/cognitive behavioral therapy is reviewed. CONCLUSION: CP/CPPS often requires a multimodal approach and alternative therapies should be considered as adjuncts in the treatment of refractory CP/CPPS patients.

Unbound bilirubin predicts abnormal automated auditory brainstem response in a diverse newborn population.

OBJECTIVE: The objective of this study was to determine if plasma unbound or 'free' bilirubin concentration (B(f)) measured during the first 30 days of life is associated with subsequent abnormal hearing screening testing by automated auditory brainstem response (AABR) in a diverse population of newborns. STUDY DESIGN: An observational study of newborns receiving AABR, plasma total bilirubin concentration (TBC) and B(f) measurements and without underlying conditions known to affect hearing was conducted. Logistic regression was used to determine associations between abnormal AABR and B(f) or TBC. The impacts of a variety of clinical factors on the regression model were also assessed. RESULT: A total of 191 patients with birth weights and gestations ranging from 406 to 4727 g and 24 to 42 weeks, respectively, were studied. Among them, 175 (92%) had normal (bilateral PASS) AABR and 16 had abnormal AABR (6 had unilateral REFER AABR, and 10 had bilateral REFER AABR). Mean TBC was not significantly different in babies with normal or abnormal AABR, but mean B(f) was greater in the latter group (1.76 versus 0.93 microg per 100 ml, respectively, P=0.012). B(f), but not TBC, was associated with an abnormal AABR (B(f) adjusted odds ratio 3.3, 95% CI 1.8 to 6.1). Comparing receiver-operating characteristics curves, the B(f)/TBC ratio was a better predictor of an abnormal AABR than B(f) alone. Intraventricular hemorrhage was the only confounding clinical variable. CONCLUSION: An abnormal AABR is associated with an elevated B(f) or B(f)/TBC ratio, but not the TBC alone. The prevalence of bilirubin neurotoxicity as a cause of audiological dysfunction may be underestimated if the TBC alone is used to assess the severity of newborn jaundice.

Peripheral nerve stimulator for the treatment of supraorbital neuralgia: a retrospective case series.

Peripheral nerve blocks of the supraorbital, supratrochlear or occipital nerve have been utilized for the relief of headaches, although relief may be short-lasting. The purpose of this study was to evaluate the efficacy of supraorbital nerve stimulation for treatment of intractable supraorbital neuralgia. Patients presenting to the pain clinic with refractory frontal headaches who responded to a diagnostic supraorbital nerve block were selected for this case series. Patients underwent a trial of supraorbital nerve stimulation, and efficacy was assessed after 5-7 days (n = 16). From the trial, 10 patients consented to undergo permanent implantation of the stimulator. Opioid consumption and headache scores were monitored preoperatively and at timed intervals for 30 weeks. Headache scores decreased, and opioid consumption was reduced in half, and these beneficial accomplishments were maintained up to 30 weeks after implantation. In selected patients, supraorbital nerve stimulation for the treatment of chronic frontal headaches appears to be efficacious.

Synthesis of (-)-[4-3H]epigallocatechin gallate and its metabolic fate in rats after intravenous administration.

Because a great deal of attention has been focused on the metabolism of (-)-epigallocatechin gallate (EGCg), quantitative analysis of this compound is required. For this purpose we developed a method of chemical synthesis of [4-(3)H]EGCg. Synthesized [4-(3)H]EGCg showed 99.5% radiochemical purity and a specific activity of 13 Ci/mmol. To clarify the excretion route of EGCg, the radioactivity levels of bile and urine were quantified after intravenous administration of [4-(3)H]EGCg to bile-duct-cannulated rats. Results showed that the radioactivity of the bile sample excreted within 48 h accounted for 77.0% of the dose, whereas only 2.0% of the dose was recovered in the urine. The excretion ratio of bile to urine was calculated to be about 97:3. These results clearly showed that bile was the major excretion route of EGCg. Time-course analysis of the radioactivity in blood was also performed to estimate the pharmacokinetic parameters following intravenous administration of [4-(3)H]EGCg. In addition, EGCg metabolites excreted in the bile within 4 h after the intravenous dose of [4-(3)H]EGCg were analyzed by HPLC. The results showed that 4',4"-di-O-methyl-EGCg was present in the conjugated form and made up about 14.7% of the administered radioactivity.

Analgesic principle from Abutilon indicum.

Bioactivity guided isolation of Abutilon indicum yielded eugenol [4-allyl-2-methoxyphenol], which was found to possess significant analgesic activity. At doses of 10, 30, and 50 mg/kg body weight, eugenol exhibited 21.30 (p < 0.05), 42.25 (p < 0.01) and 92.96% (p < 0.001) inhibition of acetic acid induced writhing in mice. At a dose of 50 mg/kg body weight, eugenol showed 33.40% (p < 0.05) prolongation of tail flicking time determined by the radiant heat method.

Molluscicidal saponins from Anagallis arvensis against schistosome intermediate hosts.

The molluscicidal activity of saponins isolated from the plant Anagallis arvensis (Primulaceae) was studied against schistosome intermediate hosts, Biomphalaria glabrata and Oncomelania quadrasi. @Strong molluscicidal activity was found in two compounds called desglucoanagalloside B and anagalloside B. Their structures were identified on the basis of chemical and spectroscopic analyses and their activities are comparable to that of the synthetic molluscicide, niclosamide.

The effects of 1-nitropyrene, 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine and 7,12-dimethylbenz[a]anthracene on 8-hydroxy-2'-deoxyguanosine levels in the rat mammary gland and modulation by dietary 1,4-phenylenebis(methylene) selenocyanate.

Humans are exposed to 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) and 1-nitropyrene (1-NP) via several environmental sources and both are known mammary carcinogens in rodents, with the former being more potent (K. El-Bayoumy, Y.-H. Chae, P. Upadhyaya, A. Rivenson, K. Kurtzke, B. Reddy, S.S. Hecht, Comparative tumorigenicity of benzo[a]pyrene, 1-nitropyrene, and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine administered by gavage to female CD rats, Carcinogenesis 16 (1995) 431-434). Following their metabolic activation, both carcinogens are known to bind covalently to DNA. However, it remains to be determined whether these carcinogens can also induce DNA-base oxidation. Our goal was to determine the effects of PhIP and 1-NP on the levels of 8-hydroxy-2'-deoxyguanosine (8-OHdG; a marker of oxidative DNA damage) in rat mammary glands and to evaluate the effect of the chemopreventive agent 1,4-phenylenebis(-methylene)selenocyanate (p-XSC) as an inhibitor of such damage. As an established potent mammary carcinogen, the synthetic 7,12-dimethylbenz[a]anthracene (DMBA) was included in this study. Female CD rats were fed a high-fat AIN-76A diet (23.5% corn oil) supplemented with p-XSC (10 ppm as selenium) or unsupplemented control diet for 1 week. At 50 days of age, each rat (12 rats/group) was gavaged with either PhIP (22 mg (100 micromol) per rat) or I-NP (20 mg (80 micromol) per rat) in trioctanoin (0.5 ml), DMBA (5 mg (20 micromol) per rat] in olive oil (0.2 ml), or the corresponding vehicle. Rats were sacrificed 6 and 24 h after carcinogen treatment (six rats per time point). Mammary fat pads were excised and DNA was isolated and enzymatically hydrolyzed. The hydrolysates were analyzed for 8-OHdG using HPLC with EC detection. PhIP significantly increased the levels of 8-OHdG by 83% after 6 h (P < 0.05), but the increase (47%) at the 24 h point was not significant. p-XSC alone had no effect on the levels of 8-OHdG. However, the elevation of 8-OHdG caused by PhIP at 6 h was significantly inhibited by p-XSC to levels similar to those measured in rats treated with the vehicle only (P < 0.05). p-XSC had no effect on PhIP-induced 8-OHdG at 24 h. I -NP had no effect on the levels of 8-OHdG at either time point. Levels of 8-OHdG were increased by 22% 6 h after DMBA administration and, significantly, rose to 84% at 24 h (P < 0.01); at either time point, this elevation was not inhibited by p-XSC. Although the mechanisms remain to be determined, to our knowledge, this is the first report demonstrating that PhIP and DMBA are capable of enhancing 8-OHdG levels in the rat mammary tissue in vivo.

Solution structure of the (+)-cis-anti-benzo[a]pyrene-dA ([BP]dA) adduct opposite dT in a DNA duplex.

Minor adducts, derived from the covalent binding of anti-benzo[a]pyrene-7,8-dihydroxy-9,10-epoxide to cellular DNA, may play an important role in generating mutations and initiating cancer. We have applied a combined NMR-computational approach including intensity based refinement to determine the solution structure of the minor (+)-cis-anti-[BP]dA adduct positioned opposite dT in the d(C1-T2-C3-T4-C5-[BP]A6-C7-T8-T9-C10-C11). (d(G12-G13-A14-A15-G16-T17-G18-A19-G20+ ++-A21-G22) 11-mer duplex. The BP ring system is intercalated toward the 5'-side of the [BP]dA6 lesion site without disrupting the flanking Watson-Crick dC5.dG18 and [BP]dA6.dT17 base pairs. This structure of the (+)-cis-anti-[BP]dA.dT 11-mer duplex, containing a bay region benzo[a]pyrenyl [BP]dA adduct, is compared with the corresponding structure of the (+)-trans-anti-[BPh]dA.dT 11-mer duplex (Cosman et al., Biochemistry 32, 12488-12497, 1993), which contains a fjord region benzo[c]phenanthrenyl [BPh]dA adduct with the same R stereochemistry at the linkage site. The carcinogen intercalates toward the 5'-direction of the modified strand in both duplexes (the adduct is embedded within the same sequence context) with the buckling of the Watson-Crick [BP]dA6.dT17 base pair more pronounced in the (+)-cis-anti-[BP]dA.dT 11-mer duplex compared to its Watson-Crick [BPh]dA.dT17 base pair in the (+)-trans-anti-[BPh]dA.dT 11-mer duplex. The available structural studies of covalent polycyclic aromatic hydrocarbon (PAH) carcinogen-DNA adducts point toward the emergence of a general theme where distinct alignments are adopted by PAH adducts covalently linked to the N(6) of adenine when compared to the N(2) of guanine in DNA duplexes. The [BPh]dA and [BP]dA N(6)-adenine adducts intercalate their polycyclic aromatic rings into the helix without disruption of their modified base pairs. This may reflect the potential flexibility associated with the positioning of the covalent tether and the benzylic ring of the carcinogen in the sterically spacious major groove. By contrast, such an intercalation without modified base pair disruption option appears not to be available to [BP]dG N(2)-guanine adducts where the covalent tether and the benzylic ring are positioned in the more sterically crowded minor groove. In the case of [BP]dG adducts, the benzopyrenyl ring is either positioned in the minor groove without base pair disruption, or if intercalated into the helix, requires disruption of the modified base pair and displacement of the bases out of the helix.

Inhibition of lung carcinogenesis by black tea in Fischer rats treated with a tobacco-specific carcinogen: caffeine as an important constituent.

Here, we examined the effect of black tea and caffeine on lung tumorigenesis in F344 rats induced by the nicotine-derived carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in a 2-year bioassay. NNK was administered s.c. at a dose of 1.5 mg/kg body weight three times weekly for 20 weeks. Animals were given either black tea as drinking water at concentrations of 2%, 1%, or 0.5%, or caffeine in drinking water at concentrations identical to those in 2% and 0.5% tea infusions for 22 weeks. The treatment period began 1 week before and ended 1 week after the NNK administration. The animals were sacrificed on week 101 for the examination of tumors in target organs, including lung, liver, nasal cavity, and other major organs. The NNK-treated group, given 2% black tea, showed a significant reduction of the total lung tumor (adenomas, adenocarcinomas, and adenosquamous carcinomas) incidence from 47% to 19%, whereas the group given 1% and 0.5% black tea showed no change. The 2% tea also reduced liver tumor incidence induced by NNK from 34% in the group given only deionized water to 12%. The tumor incidence in the nasal cavity, however, was not affected by either black tea or caffeine at any of the concentrations tested. The most unexpected finding was the remarkable reduction of the lung tumor incidence, from 47% to 10%, in the group treated with 680 ppm caffeine, a concentration equivalent to that found in the 2% tea. This incidence is comparable to background levels seen in the control group. This study demonstrated for the first time in a 2-year lifetime bioassay that black tea protects against lung tumorigenesis in F344 rats, and this effect appears to be attributed, to a significant extent, to caffeine as an active ingredient of tea.

Effects of 1,4-phenylenebis(methylene)selenocyanate and selenomethionine on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced tumorigenesis in A/J mouse lung.

We reported earlier that continuous feeding of 1,4-phenylenebis(methylene)selenocyanate (p-XSC) inhibited lung tumor induction by the tobacco-specific nitrosamine, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the A/J mouse (El-Bayoumy et al., Carcinogenesis, 14, 1111-1113, 1993). The present investigation was designed to determine whether p-XSC inhibits pulmonary neoplasia induced by NNK in female A/J mice during the initiation phase of carcinogenesis or during the post-initiation phase. The naturally occurring selenomethionine was also included in this study. Doses higher than 4 p.p.m. of selenomethionine can induce toxic effects, therefore, dietary supplementation of this compound was selected at a dose level of 3.75 p.p.m. However, we were able to give p-XSC at selenium levels of 7.5 and 15 p.p.m., as mice can tolerate such doses in this form without any adverse effects. NNK was given by a single i.p. injection at dose of 10 micromol in 0.1 ml of saline. Selenomethionine did not show chemopreventive activity when administered in either phase of tumorigenesis. In contrast, p-XSC significantly reduced lung tumor multiplicity regardless of whether it was given during the initiation phase of tumorigenesis (P = 0.0009 at both levels of selenium) or post-initiation (P = 0.0009 at 15 p.p.m. and P = 0.036 for 7.5 p.p.m.). This is the first report describing that the synthetic organoselenium compound, p-XSC, can effectively block and suppress chemically (NNK)-induced lung tumor development in mice.

Lack of tumorigenicity of cholesterol epoxides and estrone-3,4-quinone in the rat mammary gland.

The purpose of this study is to test the long-standing hypothesis that endogenous agents found in human breast fluid and in plasma are potential initiators of breast cancer. Therefore, we evaluated the tumorigenicity in the mammary glands of female CD rats of cholestan-5 alpha,6 alpha-epoxy-3 beta-ol (cholesterol-alpha-epoxide), cholestan-5 beta,6 beta-epoxy-3 beta-ol (cholesterol-beta-epoxide), and 1,5(10)estradiene-3,14,17-trione (estrone-3,4-quinone). As a positive control, trans-3,4-dihydroxy-anti-1,2-epoxy-1,2,3,4-tetrahydrobenzo[c]phenanthren e (BcPDE) was used. Rats were fed a high-fat AIN-76A diet (23.5% corn oil) to mimic the Western dietary composition. Because literature data suggest that the endogenous agents tested in this study are weak electrophiles, the total doses of cholesterol epoxides (12.3 mumol/rat) and of estrone-3,4-quinone (30 mumol/rat)were 10- and 25- fold higher, respectively, than that of BcPDE (1.2 mumol/rat). Each agent was dissolved in DMSO, and one-sixth of the total dose was injected under each of six nipples on the right side. The thoracic glands of the rat were treated at 30 days of age, and those located in the inguinal area were treated on the following day. The experiment was terminated at 44 weeks after treatment. Consistent with our previous study, BcPDE was a strong mammary carcinogen. However, there were no differences between rats treated with DMSO alone or those receiving DMSO containing cholesterol-alpha-epoxide, cholesterol-beta-epoxide, or estrone-3,4-quinone. The results of this study clearly indicate, for the first time, that metabolites derived from cholesterol and estrone lack tumorigenic activity in the rat mammary gland, at least under the conditions of the present protocol.

Effects of dietary 1,4-phenylenebis(methylene)selenocyanate on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced DNA adduct formation in lung and liver of A/J mice and F344 rats.

1,4-Phenylenebis(methylene)selenocyanate (p-XSC) was tested for its ability to inhibit DNA adduct formation induced by the tobacco-specific N-nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the liver and lung of A/J mice and F344 rats. Dietary p-XSC, providing a dose of 5 p.p.m. selenium, significantly inhibited the formation of 7-methylguanine (7-mGua) induced by a single i.p. injection of 10 mumol of NNK(12.8% inhibition at 4 h and 19.9% at 96 h) and O6-methylguanine (O6-mGua) (16.5% at 4 h and 34.8% at 96 h) in the liver of A/J mice. Dietary supplements of p-XSC providing 15 p.p.m. of selenium reduced the levels of 7-mGua by 17.3% (4 h) and 33.6% (96 h). The formation of O6-mGua was inhibited by 69.5% (4th) and 73.8 (96h). In A/J mouse lung DNA the most significant reduction was observed in levels of O6-mGua. Dietary p-XSC at 5 p.p.m. as selenium inhibited the formation of this adduct by 73.1% (4 h). Ninety-six hours after NNK injection, and at both time points with p-XSC providing 15 p.p.m. selenium, O6-mGua was not detected. Although levels of 7- mGua in mouse lung DNA were also reduced, this was significant only 4 h after carcinogen administration. In general, selenite at a5 p.p.m. as selenium had no significant effect on the levels of these lesions; however, it inhibited O6-mGua in the liver only 4 h after NNK administration. These effects may explain why there is chemopreventive activity for p-XSC, but not for selenite, in NNK-induced lung carcinogenesis in A/J mice. Moreover, these findings raised our interest in determining the potential chemopreventive activity of p-XSC against NNK-induced lung adenocarcinomas in male F344 rats by first determining its effects on NNK-induced DNA methylation in the lungs of rats. Diet supplemented with 10 p.p.m. selenium as p-XSC did indeed inhibit the formation of adducts in pulmonary DNA of F344 rats treated with four consecutive injections of 81 mg/kg of NNK. Statistically significant inhibition of O6-mGua formation was observed 4 h after carcinogen treatment in both pulmonary (49.1% inhibition) and hepatic (39.8%) DNA. Statistically significant inhibition of 7-mGua formation was also measured in lung DNA isolated 24 h after the last NNK injection (45.0%) and in liver DNA 4 h after carcinogen treatment (31.8%). These results suggest that p-XSC would also inhibit induction of lung adenocarcinoma in male F344 rats by NNK.

Effects of dietary fat content on the metabolism of NNK and on DNA methylation induced by NNK.

The available data support the concept that high-fat diets increase cytochrome P-450 activities in the liver, leading to increased rates of carcinogen metabolism and, in some instances, DNA adduct formation. Therefore we investigated whether a high-fat diet can also influence DNA methylation by the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) in the lungs of rats. Male F344 rats were fed a regular AIN-76A low-fat (5% corn oil) or AIN-76A high-fat (23.5% corn oil) diet. After three weeks on this dietary regimen, the animals were injected subcutaneously once daily for four days with NNK at 0.39 mmol/kg body wt. Groups of rats were sacrificed 4 and 24 hours after the last NNK administration; livers and lungs were excised for DNA isolation. We found that the high-fat diet significantly enhanced the formation of O6-methylguanine (O6-mGua) in the rat lung four hours (p < 0.01) after the last carcinogen administration. This may, in part, account for our previous finding in regard to the enhancing effect of the high-fat diet on NNK-induced lung carcinogenesis. There was no effect on O6-mGua or 7-mGua in the rat liver at either time point. To further elucidate the enhancing effect of the high-fat diet on DNA methylation by NNK in the lung, we determined its effect on the in vitro and in vivo metabolism of NNK. The in vitro data indicated that dietary fat has no measurable effect on liver and lung microsomal mixed-function oxidase in catalyzing the metabolic activation of NNK. The results of the metabolism study of NNK in vivo appear to be consistent with the in vitro finding, in that fat had no effect on the excretion pattern of NNK or on the distribution pattern of its urinary metabolites. It is apparent that the enhancing effect of the high-fat diet on O6-mGua in the lung of rats that was measured four hours after NNK injection requires future investigations.

Inhibition of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone tumorigenicity in mouse lung by the synthetic organoselenium compound, 1,4-phenylenebis(methylene)selenocyanate.

The chemopreventive effect of 5, 10 and 15 p.p.m. (as selenium) of 1,4-phenylenebis(methylene)selenocyanate (p-XSC) on lung tumor induction by the tobacco-specific 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) was examined in female A/J mice by administering p-XSC in the diet. Sodium selenite (5 p.p.m. selenium) was given in the same manner for comparison with p-XSC. Mice were fed experimental diets containing the selenium compounds 1 week before i.p. injection of 10 mumol NNK in 0.1 ml saline and throughout the experiment until termination, 16 weeks after carcinogen administration. Body weights of the mice in the different dietary groups did not differ significantly. p-XSC significantly inhibited lung tumor multiplicity from 7.6 tumors per mouse in the control group to 4.1, 3.3 and 1.8 tumors per mouse in animals given 5, 10 and 15 p.p.m. of selenium respectively. In contrast, 5 p.p.m. sodium selenite had no protective effect against lung tumor induction. The results of this study clearly indicate that the structure of selenium-containing compounds is important in determining their efficacy as chemopreventive agents.