Lipopolysaccharide-induced increase in plasma nitrotyrosine concentrations in rats

Since the production of peroxynitrite may contribute to the pathophysiology of endotoxemia or sepsis, the quantities of the produced peroxynitrite were evaluated in rats after lipopolysaccharide (LPS) treatment by measuring plasma nitrotyrosine concentrations with a new method. The intraperitoneal administration of LPS caused a persistent increase in plasma nitrotyrosine concentrations, which reached a maximum with 6-fold level of the base line (105 pmol ml-1) at 24 h and gradually declined to 3-fold level of the base line at 7 days. However, plasma concentrations of nitrite and nitrate peaked at 18 h, returning to base line within 48 h. The effect of LPS on the increase in plasma concentration of nitrotyrosine was dose-dependent and consistent with that of nitrite and nitrate concentrations. On the other hand, intravenous injection of nitrotyrosine revealed a rapid clearance with a plasma half-life of 1.67 h. These results indicate that the elevation of plasma nitrotyrosine concentrations may persist for more than a week after LPS treatment, and that the determination of plasma nitrotyrosine concentrations may be useful to detect the previous peroxynitrite-dependent oxidative damages.

Loss of heterozygosity of the retinoblastoma gene in liver cirrhosis accompanying hepatocellular carcinoma

Carcinogenesis is a multistep process. Most hepatocellular carcinoma (HCC) is preceded by liver cirrhosis, but the genetic changes involved in cirrhosis are not known well. The present study was conducted to evaluate aberration of the retinoblastoma (RB) gene in HCC and adjacent non-tumorous liver using 22 patients with chronic liver damage accompanying HCC. The specimens obtained by microdissection from paraffin-embedded tissues were analyzed using an assay based on the polymerase chain reaction for highly polymorphic nucleotide sequences of microsatellites in the RB gene. Out of 22 cases, 15 showed constitutional heterozygosity for the microsatellite markers. In 11 (73.3%) of these 15 informative cases, the primary HCC foci showed loss of heterozygosity (LOH). In 8 of these 11 doubly informative (informative and LOH-positive in primary HCC) cases, LOH was found in 20 (64.5%) of 31 microdissected non-tumorous foci. All of the non-tumorous foci showing RB loss were cirrhotic lesions but there were no foci of chronic hepatitis. The remaining 4 cases without LOH in HCC foci showed no LOH in non-tumorous lesions. In our study, LOH of the RB gene was frequently observed in liver cirrhosis surrounding tumor.

Effects of cimetidine on acute gastric mucosal injury induced by ischemia-reperfusion in rats

We investigated the effects of cimetidine on acute gastric mucosal injury induced by ischemia-reperfusion in rats. Under pentobarbital anesthesia, the celiac artery was clamped for 30 min and reperfused for 60 min. Cimetidine, famotidine and omeprazole caused a dose-dependent suppression in the total area of erosions that were induced by ischemia-reperfusion. Whereas, none of them inhibited the increase in thiobarbituric acid-reactive substances in the stomach, as an index of lipid peroxidation. The inhibitory effect of intraperitoneally administered cimetidine on mucosal damage was abolished by continuous luminal perfusion with HCl solution (pH 1.5, 1 ml/min) during ischemia-reperfusion, while luminal perfusion with the solution containing HCl and cimetidine (3 mmol/l) significantly reduced the total area of erosions compared to luminal perfusion with HCl solution alone. Cimetidine (3 mmol/l) inhibited hydroxyl radical-induced lipid peroxidation of human erythrocyte membranes by 60% in vitro. These results indicate that cimetidine possesses a protective effect against acute gastric mucosal injury induced by ischemia-reperfusion not only due to the suppression in gastric acid secretion, but also due to the antioxidant action when it is present at a high concentration in the intragastric environment.

Effect of plaunotol on gastric injury induced by ischaemia-reperfusion in rats

Plaunatol, an anti-ulcer drug, increases prostaglandin content in gastric tissue but its effect on radical-mediated gastric damage or activity against reactive oxygen species is unknown. We examined the effects of oral administration of plaunotol (Kelnac) on the acute gastric mucosal lesion and its progression to ulcer lesion induced by ischaemia-reperfusion in rats. Plaunotol (30 and 100 mg kg-1, 15 min before ischaemia) significantly reduced the total erosion area observed immediately after ischaemia-reperfusion. When plaunotol (30 and 100 mg kg-1, once a day) was administrated orally 60 min after reperfusion, it prevented the progression from erosion to ulcer. At 72 h after ischaemia-reperfusion, the total area of ulcers lesions was significantly reduced compared with that without plaunotol administration. Furthermore, treatment with plaunotol (100 mg kg-1) significantly increased prostaglandin E2 content in gastric tissues of both acute gastric mucosal lesion and gastric ulcer lesion. In in-vitro experiments, plaunotol (1-3 mg mL-1) reduced the superoxide radicals generated by leucocytes, but not by xanthine oxidase. These results indicate that plaunotol has protective effects on both the onset of acute gastric mucosal injury and its progression to ulcer lesion induced by ischaemia-reperfusion. Both effects of plaunotol on increase in prostaglandin content in gastric tissues and inhibition of superoxide radical from leucocytes may play important roles on the protection against gastric mucosal injury.

Loss of the tumor suppressor p53 gene at the liver cirrhosis stage in Japanese patients with hepatocellular carcinoma

The incidence of p53 gene aberrations is reported to be about 20-50% in hepatocellular carcinomas (HCCs). In most cases, HCC is clinically preceded by liver cirrhosis, but the genetic changes in cirrhosis are not known well. Therefore, we studied the loss of heterozygosity (LOH) of the p53 gene in cirrhotic and neoplastic foci in the livers of patients with HCC. To assess the relationship between the LOH status of the p53 gene in the liver cirrhosis stage and that in HCC, we analyzed the samples microdissected from paraffin-embedded tissues using the polymerase-chain-reaction-based assay. We studied 18 patients with HCC. Fourteen of the 18 cases showed constitutional heterozygosity for the microsatellite markers. In 8 (57%) of the 14 informative cases, LOH was detected in primary HCCs. Among these 8 doubly informative (informative and LOH positive in primary HCC) cases, 5 cases (63%) showed LOH in liver cirrhosis lesions. The pattern of p53 allelic loss in the cirrhotic foci was identical with that in the corresponding tumor. The remaining 6 cases without LOH of the p53 gene in HCC showed on p53 loss in any cirrhotic foci. LOH of the p53 gene may occur before the development of HCC.

Substances in the aqueous fraction of cigarette smoke inhibit lipid peroxidation in synaptosomes of rat cerebral cortex

The effects of water-soluble substances in cigarette smoke on lipid peroxidation were investigated using nerve terminals prepared from the rat cerebral cortex. The prepared smoke-substances significantly reduced the spontaneous increase in thiobarbituric acid-reactive substances in synaptosomes in a dilution factor-dependent manner. Furthermore, the aqueous extract also inhibited the elevation of lipid peroxidation induced by 2,2'-azobis (2-amidinopropane) dihydrochloride, a peroxyl radical generator. Smoke-substances scavenged superoxide radicals generated from stimulated human leukocytes and from the xanthine/xanthine oxidase system. These effects were not mimicked by nicotine. The antioxidant effects of smoke-substances were preserved for several days at 5 degrees or -80 degrees C. The results suggest that the smoke-substances may possess long half-lives and scavenge the radicals which cause lipid-peroxidation in synaptosome membranes.

Protective effect of acetaminophen against acute gastric mucosal lesions induced by ischemia-reperfusion in the rat

We examined the effect of acetaminophen, an analgesic and antipyretic drug, on acute gastric mucosal injury induced by ischemia-reperfusion in rats. Ischemia-reperfusion was induced by clamping the celiac artery for 30 min with a small clip. Sixty minutes after reperfusion, the total area of erosions was measured. Acetaminophen (300 and 500 mg/kg) administered intraperitoneally 90 min before the ischemia significantly reduced the total area of erosions. The drug also inhibited the increase in lipid peroxide levels induced by ischemia-reperfusion in the gastric tissue and the increase in lipid peroxidation caused by the hydroxyl radical, OH., in vitro. Gastric prostaglandin E2 (PGE2) contents tended to increase after ischemia-reperfusion in both control and acetaminophen-treated groups. A significant difference in gastric PGE2 contents between control and acetaminophen-treated groups was not observed. The results indicate that acetaminophen may protect the gastric mucosa against ischemia-reperfusion injury, probably by blocking hydroxyl-radical-induced membrane damage.

Effects of sucralfate on acute gastric mucosal injury and gastric ulcer induced by ischemia-reperfusion in rats

We have revealed that acute gastric mucosal injury induced by a single ischemia-reperfusion (I-R) treatment develops into an ulcerative lesion within a few days. In the present studies, we examined the effects of oral administration of sucralfate on gastric damage induced by I-R. Sucralfate (1-100 mg/kg, 15 min before I-R) significantly reduced the total erosion area observed immediately after I-R. A high dose of sucralfate (30-100 mg/kg) inhibited the increase in the thiobarbituric acid-reactive substances, an index of lipid peroxidation, induced by I-R, although a low dose of it failed. When sucralfate (30 mg/kg, once a day) was orally administered after I-R, it prevented mucosal damage from developing into gastric ulcers: the total area of the ulcers was significantly reduced compared to that without sucralfate administration 72 h after I-R. High concentrations of sucralfate (3-10 mg/ml) reduced the superoxide radicals generated by leukocytes or xanthine-xanthine oxidase, and protected erythrocyte membrane ghosts against lipid peroxidation induced by hydrogen peroxide and Fe2+ in vitro. These results indicate that sucralfate may prohibit both the generation of acute gastric mucosal injury and its progression to ulcer induced by I-R, probably due to a cytoprotective action on the mucosal surface. However, the protective mechanism may involve an inhibitory action on superoxide and hydroxyl radicals at high doses.

Quantitative analysis of cyclooxygenase-2 gene expression on acute gastric injury induced by ischemia-reperfusion in rats

The rat model of acute gastric damage induced by ischemia-reperfusion (I-R) has been used to evaluate the protective effect of various drugs on gastric injury. However, the quantitative expression state of cyclooxygenase-2 (COX-2), a protein which induces cytoprotective prostaglandins during inflammation, is still unknown in acute gastric injury induced by I-R. Therefore, we have quantitatively investigated the level of expression of COX-2 mRNA in injured gastric tissue of this model using the reverse transcription-competitive polymerase chain reaction method. The mRNA for COX-2 was expressed at low or undetectable levels in the normal gastric tissues in control rats, which were fasted for 18 hrs without I-R. The mRNA levels of COX-2 in injured gastric tissues were higher than those of control tissues between 6 hrs and 48 hrs after I-R. The maximum expression of COX-2 mRNA was recorded at 24 hrs (approximately a 200-fold increase). The expression state of COX-2, which has been ascertained in this study, should be useful in evaluating the effect of various drugs on the expression of COX-2 in acute gastric damage.

Inhibition by cigarette smoke of lipid peroxidation-induced neurotransmitter release

Effects of water-soluble substance in cigarette smoke on neurotransmitter release were investigated using nerve terminals (synaptosomes) prepared from rat cerebral cortex. 2,2'-Azobis (2-amidinopropane) dihydrochloride (ABAP), a peroxyl radical-generator, enhanced the depolarization-evoked release of glutamate and aspartate from synaptosomes with concomitant increase in thiobarbituric acid-reactive substances (TBA-RS) levels in membrane lipids of synaptosomes. The trapped smoke-substance attenuated the lipid peroxidation-enhanced release of excitatory amino acids during the depolarization with reduction in TBA-RS, although it failed to affect the basal release of neurotransmitters. These data suggest that cigarette smoke may possess antioxidant properties to reduce oxidation-induced enhancement of transmitter release from nerve terminals.

Effects of cigarette smoke on nitric oxide-induced increase in cyclic GMP in nerve terminals of rat cerebral cortex

Since nitric oxide (NO) has been widely accepted as a novel neuromodulator, which activates soluble forms of guanylate cyclase to increase in guanosine 3':5'-cyclic monophosphate (cyclic GMP) levels, the effect of water-soluble substance in cigarette smoke on cyclic GMP levels were investigated using nerve terminals prepared from rat cerebral cortex. Although the smoke-substance itself failed to affect cyclic GMP levels in the synaptosomes, the smoke-substance significantly inhibited the increases in cyclic GMP levels induced by NO donors. The blocking effect of the smoke-substance was inhibited by concomitant incubation with superoxide dismutase, but not with mannitol. In addition, the effect of smoke-substance was mimicked by products of the xanthine/xanthine oxidase system, but not by nicotine. The effect of smoke-substance was preserved at least 7 days after they were stored at room temperature. Therefore, these results suggest that the smoke-substance may possess long half-lives to produce the radicals which inactivate NO, and to inhibit the increase in cyclic GMP levels in nerve terminals. The interference with NO may explain the part of mechanism in effects of cigarette smoke on neuronal functions.

Sensitive determination of nitrotyrosine in human plasma by isocratic high-performance liquid chromatography

A highly sensitive and simple isocratic high-performance liquid chromatographic method was developed for determination of 3-nitrotyrosine in human plasma with precolumn derivatization with 4-fluoro-7-nitrobenzo-2-oxa-1,3-diazole. The precision of the method was satisfactory (coefficient of variation 4.8%), and the detection limit was established at 0.1 pmol of 3-nitrotyrosine allowing the determination at the level of 6 pmol/ml in human plasma. The recoveries of 3-nitrotyrosine and alpha-methyltyrosine, an internal standard, were 89.3 +/- 7.1 and 85.7 +/- 7.6%, respectively. The 3-nitrotyrosine level was 31 +/- 6 pmol/ml (mean +/- S.D., n = 9) in plasma from healthy volunteers. Since 3-nitrotyrosine is a stable product of peroxynitrite, an oxidant formed by a reaction of nitric oxide and superoxide radicals, the measurement of its plasma concentration may be useful as a marker of nitric oxide-dependent oxidative damage.

Frequent loss in chromosome 8p loci in liver cirrhosis accompanying hepatocellular carcinoma

Most hepatocellular carcinoma (HCC) is preceded by liver cirrhosis, but the genetic changes involved in cirrhosis are not well understood. We therefore studied loss of heterozygosity (LOH) in cirrhotic and neoplastic foci in livers of 14 patients with HCC. The samples, microdissected from paraffin-embedded tissues, were analyzed using a polymerase-chain-reaction-based assay for dinucleotide repeat polymorphisms on 8p. Of the 14 cases, 13 showed constitutional heterozygosity for the microsatellite markers. In 7 (54%) of these 13 informative cases, LOH was detected in the primary HCC and, in these 7 doubly informative (informative and LOH-positive in primary HCC) cases, LOH was found in 16 (70%) of 23 liver cirrhotic foci. The pattern of 8p allelic loss was identical in each doubly informative tumor; however, some of the liver cirrhotic foci harbored an 8p loss identical to that seen in the primary HCC, some harbored a different 8p loss, and some did not harbor any 8p loss. The remaining 6 cases without LOH on 8p in HCC showed no 8p loss in any cirrhotic foci. Presumably HCC could develop from cirrhotic cells harboring 8p loss.

A new gastric ulcer model induced by ischemia-reperfusion in the rat: role of leukocytes on ulceration in rat stomach

A new model of gastric ulcer involving damage to the muscularis mucosae was developed by clamping the celiac artery in rat to induce ischemia-reperfusion (I-R) injury. Although erosions with falling off of the gastric mucosa were observed immediately, 24 and 36 hours after the I-R, gastric ulcers involving the injury of muscularis mucosae were observed in the area of gastric glands at 48 and 72 hours after initiation of injury. Administration of omeprazol, a proton pump inhibitor, or pentoxifylline, an anti-leukocyte drug, just after the initiation of injury significantly decreased the total area of ulcers at 72 hours. A combination of omeprazol and pentoxifylline was more effective than either drug alone. An anti-leukocyte adhesion molecule (anti-CD18 antibody) also showed significant inhibitory effect on the development of ulcers at 72 hours and the infiltration of leukocytes into both submucosa and mucosa. These results indicate that in our model, gastric acid together with leukocytes contribute to the development of ulcers following erosions. This model may be used to investigate the mechanisms of the development of gastric ulcer and evaluate antiulcer drugs in a preclinical setting.

Advanced maternal age: perinatal outcome when controlling for physician selection

OBJECTIVE

Our purpose was to determine whether differences in maternal outcome because of maternal age could be controlled by the elimination of bias in physician selection.

STUDY DESIGN

We performed a case-control study that compared pregnancy outcomes of 164 patients delivered at our institution at > or = 40 years old with outcomes in a control group consisting of the next two deliveries by the same attending physician of women with ages 20 to 29 years. Retrospective analysis of the antepartum and intrapartum records was done to compare clinical outcome.

RESULTS

We observed a significant increased incidence of nulliparous cesarean delivery (p = 0.046), elevated results of glucose screens with a 50 gm load (p = 0.00002), and hypertension throughout pregnancy in the older patients in spite of controlling for physician selection. The older patient group was more likely to have used assisted reproductive techniques (p = 0.000005) and had higher baseline weights (p = 0.001) and maximum pregnancy weights (p = 0.042). However, the neonatal outcome was similar in both groups. Despite controlling for physician selection, we demonstrated increased rates of abdominal delivery, glucose intolerance, and hypertension in older patients. Fetal and neonatal outcomes were similar in both groups.

CONCLUSION

Women > or = 40 years old tend to have an increased incidence of a few pregnancy-related complications, even when controlling for physician selection.

Effect of cystathionine as a scavenger of superoxide generated from human leukocytes or derived from xanthine oxidase in vitro

We studied the direct effects of cystathionine on human leukocyte-generated or xanthine-xanthine oxidase-derived superoxide radicals in vitro. Washed leukocyte suspensions (10(6) cells/ml) prepared from healthy male volunteers were stimulated with phorbol myristate acetate (1 mu M) or opsonized zymosan (1 mg/ml) to generate superoxide radicals, which were measured with a 2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-alpha] pyrazin-3-one hydrochloride (MCLA)-chemiluminescence method. Cystathionine (30 mu M to 10 mM) significantly reduced superoxide radical-dependent chemiluminescence in the leukocyte system in a concentration-dependent manner. In addition, in the two different methods of determination of superoxide radicals (MCLA chemiluminescence and nitroblue tetrazolium reduction), cystathionine significantly scavenged the superoxide radicals derived from the xanthine-xanthine oxidase system. However, cystathionine did not inhibit the activity of xanthine oxidase during superoxide generation. On the other hand, cystathionine did not show a scavenging effect against hydroxyl radicals derived from Fe2+ -H2O2 on the erythrocyte membrane. These results indicate that cystathionine itself may possess a scavenging function against superoxide radicals rather than against hydroxyl radicals in vitro.

Release of taurine and its effects on release of neurotransmitter amino acids in rat cerebral cortex

Taurine has been postulated to function as a neurotransmitter or neuromodulator. The possibility of depolarization-evoked release of taurine from nerve terminals, and the effects of taurine on release of endogenous glutamate (Glu), aspartate (Asp), and gamma-aminobutyrate (GABA) were examined using a superfusion of crude synaptosomes prepared from rat cerebral cortex. Taurine contents in cerebral cortex and its synaptosomes were 31.7 and 25.2 nmol/mg protein, respectively. Although the basal rate of taurine release was 35.3 pmol/min/mg protein of synaptosomes (second highest releasing rate), the 2-min stimulation with KCl (30 mM) evoked only a 1.3-fold increase in release of taurine (47.3 pmol/min/mg). The increase was largely Ca(2+)-dependent. The addition of taurine to the perfusion medium significantly reduced the depolarization-evoked increases in Glu, Asp, and GABA release. The taurine-induced reduction in GABA release was attenuated by phaclofen, a GABAB antagonist, but not by bicuculline, a GABAA antagonist. However, these antagonists did not block the effects on Glu and Asp release. These data suggest that taurine may be only partly released from nerve terminals by depolarization in the cerebral cortex, but that taurine may act upon nerve terminals to regulate the release of excitatory and inhibitory amino acid transmitters.

Protective effect of cystathionine on acute gastric mucosal injury induced by ischemia-reperfusion in rats

We studied the protective effect of cystathionine on acute gastric mucosal injury induced by ischemia-reperfusion in rats. Under pentobarbital anesthesia, the celiac artery was clamped for 30 min and reperfused. Sixty minutes after the reperfusion, the total area of erosions and thiobarbituric acid-reactive substances in the stomach, as an index of lipid peroxidation, were measured and compared between control and cystathionine-treated groups. Intraperitoneal administration of cystathionine (1-20 mg/kg) 10 min before the ischemia significantly reduced both the total area of erosions and the level of thiobarbituric acid-reactive substances. When cystathionine (10 mg/kg) was administered orally, the significant reductions in the total area of erosions and level of thiobarbituric acid-reactive substances were also observed. There was a good correlation between the total area of erosions and the level of thiobarbituric acid-reactive substances. Cystathionine did not affect blood flow during ischemia-reperfusion. These results indicate that the protective effect of cystathionine on acute gastric mucosal injury induced by ischemia-reperfusion may be due to the scavenging action against superoxide radicals in vivo.

Nitric oxide regulates substance P release from rat spinal cord synaptosomes

In order to determine whether nitric oxide (NO) acts directly upon nerve terminals to regulate the synaptic transmission at the level of spinal cord, effects of NO-donors on release of substance P (SP) and glutamic acid (Glu) were investigated by superfusion of synaptosomes prepared from the rat spinal cord. Basal levels of endogenous SP and Glu release were 5.99 +/- 2.50 fmol/min/mg of protein and 26.2 +/- 4.8 pmol/min/mg of protein, respectively. Exposure to a depolarizing concentration of KCI evoked 2.7- and 3.8-fold increases in SP and Glu release in a calcium-dependent manner, respectively. Sodium nitroprusside (NP) caused a reduction in the depolarization-evoked overflow of SP in a concentration-dependent manner without affecting its basal release, although it failed to affect either basal or evoked release of Glu. The reduction in SP overflow was also observed by the perfusion with S-nitroso-N-acetyl-penicillamine or membrane-permeable cyclic GMP, but not with cyclic AMP. NP caused the concentration-dependent increases in cyclic GMP levels in synaptosomes. Together with reports that excitatory amino acids stimulate NO synthase and release NO in the spinal cord, these data suggest that there may be an interaction between nerve terminals containing Glu and SP, and that NO may directly participate in the regulation of synaptic transmission in SP-containing nerve terminals, which may be mediated through the activation of guanylate cyclase and the increase in cyclic GMP levels.

In vitro effectiveness of mouthrinses against Candida albicans

This study assessed the antifungal activity of seven commercial mouthrinses against Candida albicans, the organism often found in denture wearers with denture stomatitis. Screening for efficacy of growth inhibition found that five mouthrinses inhibited the growth of fungi, and their maximum inhibitory dilution values and the fungicidal activity were then determined. Two mouthrinses containing cetylpyridinium chloride were shown to be most effective after determination of the maximum inhibitory dilution and the test of fungicidal activity.

Nitric oxide inhibition of the depolarization-evoked glutamate release from synaptosomes of rat cerebellum

Effects of nitric oxide (NO) on release of amino acid transmitter were investigated by superfusion of synaptosomes prepared from rat cerebellum. After constant basal levels of amino acid release were obtained, exposure to a depolarizing concentration of KCl (30 mM) evoked 4.05-, 2.18- and 3.00-fold increases in release of glutamic acid (Glu), aspartic acid (Asp) and gamma-aminobutyric acid (GABA) from synaptosomes. The perfusion with NO-donors inhibited the evoked increases in release of Glu and Asp in a concentration-dependent manner, but not that in GABA release. A membrane-permeable analog of cyclic GMP, but not that of cyclic AMP, caused a similar reduction in the evoked release. The concentration of nitroprusside to increase cyclic GMP levels corresponded to that of nitroprusside to reduce the evoked release. These data suggest that NO may directly act upon the nerve terminals to inhibit release of excitatory amino acid transmitters.

In vitro study on the effects of trial denture cleansers with berberine hydrochloride

The antifungal activity of trial denture cleansers prepared with berberine hydrochloride was examined against Candida albicans, C. tropicalis, and C. glabrata. A commercial denture cleanser and a trial denture cleanser that exhibited strong antifungal activity were tested for their effects on Candida spp., the color stability of the dental material, and the surface roughness of acrylic resin plates. The results of these tests revealed that the trial denture cleanser removed 64% to 89% of adhered cells from acrylic resin surfaces and had little effect on the other physical properties tested.

Human papillomavirus not found in squamous and large cell lung carcinomas by polymerase chain reaction

BACKGROUND

Human papillomavirus (HPV) has been identified not only in anogenital carcinomas, but also in malignancies of other organs, including bronchogenic carcinomas. Previous studies reporting detection of these viruses in lung cancers used mainly in situ hybridization. The authors applied the polymerase chain reaction (PCR) for investigating the occurrence of HPV in bronchial neoplasms.

METHODS

Formalin fixed, paraffin embedded tissues of 40 squamous and 7 large cell lung cancers were examined. PCR was done with consensus primers, capable of detecting HPV 6, 11, 16, 18, 31, 33, 52b, and 58.

RESULTS

None of the 47 samples contained any of the examined HPV types.

CONCLUSIONS

Because the squamous and large cell cancer cases were found not to be associated with HPV infection, this study does not support the potential role of these viruses in the development of lung cancers.