Regular disappearance of the human papillomavirus genome after conization of cervical dysplasia by carbon dioxide laser.

OBJECTIVE: We wished to evaluate the effectiveness of treatment of cervical dysplasia by laser conization in relation to persistence of human papillomavirus after treatment. STUDY DESIGN: Of 203 women referred to colposcopy because of an abnormal Papanicolaou smear, 149 women could be followed up for 3 years. A total of 108 women were treated by carbon dioxide laser excision, 4 women were treated by carbon dioxide laser evaporation, and 37 women were merely followed up. Cervical samples were taken before treatment and at follow-up 3 years later and were analyzed by nested general primer polymerase chain reaction for human papillomavirus deoxyribonucleic acid. RESULTS: Among women treated by laser conization, 82 (73.2%) had positive results for human papillomavirus deoxyribonucleic acid before treatment. Three women (2.7%) had a positive finding at follow-up, but no woman had the same human papillomavirus type on both occasions. Eighty-eight women had grade 1 to grade 3 cervical intraepithelial neoplasia before treatment, whereas during follow-up only 2 squamous cells atypias were found. CONCLUSION: The human papillomavirus genome present before treatment was regularly cleared, and there was also no recurrence of dysplasia. The results suggest that human papillomavirus testing is useful for monitoring the efficacy of treatment and that treatment modalities resulting in clearance of human papillomavirus should be favored.

Smoking, diet, pregnancy and oral contraceptive use as risk factors for cervical intra-epithelial neoplasia in relation to human papillomavirus infection.

Smoking, nutrition, parity and oral contraceptive use have been reported as major environmental risk factors for cervical cancer. After the discovery of the very strong link between human papillomavirus (HPV) infection and cervical cancer, it is unclear whether the association of these environmental factors with cervical cancer reflect secondary associations attributable to confounding by HPV, if they are independent risk factors or whether they may act as cofactors to HPV infection in cervical carcinogenesis. To investigate this issue, we performed a population-based case-control study in the Vasterbotten county of Northern Sweden of 137 women with high-grade cervical intra-epithelial neoplasia (CIN 2-3) and 253 healthy age-matched women. The women answered a 94-item questionnaire on diet, smoking, oral contraceptive use and sexual history and donated specimens for diagnosis of present HPV infection (nested polymerase chain reaction on cervical brush samples) and for past or present HPV infections (HPV seropositivity). The previously described protective effects of dietary micronutrients were not detected. Pregnancy appeared to be a risk factor in the multivariate analysis (P < 0.0001). Prolonged oral contraceptive use and sexual history were associated with CIN 2-3 in univariate analysis, but these associations lost significance after taking HPV into account. Smoking was associated with CIN 2-3 (odds ratio (OR) 2.6, 95% confidence interval (CI) 1.7-4.0), the effect was dose-dependent (P = 0.002) and the smoking-associated risk was not affected by adjusting for HPV, neither when adjusting for HPV DNA (OR 2.5, CI 1.3-4.9) nor when adjusting for HPV seropositivity (OR 3.0, CI 1.9-4.7). In conclusion, after taking HPV into account, smoking appeared to be the most significant environmental risk factor for cervical neoplasia.

Type-specific persistence of human papillomavirus DNA before the development of invasive cervical cancer.

BACKGROUND: Infection with the human papillomavirus (HPV) has been established as a cause of cervical cancer, but the association between a positive test for HPV DNA and the risk of the subsequent development of invasive cervical cancer is unknown. METHODS: In a study of women who participated in a population-based screening program for cancer of the cervix in Sweden from 1969 to 1995, we compared the proportion of normal cervical smears (Pap smears) that were positive for HPV DNA among 118 women in whom invasive cervical cancer developed an average of 5.6 years later (range, 0.5 month to 26.2 years) with the proportion of HPV DNA-positive smears from 118 women who remained healthy during a similar length of follow-up (controls). The control women were matched for age to the women with cancer, and they had had two normal Pap smears obtained at time points that were similar to the times of the baseline smear and the diagnosis of cancer confirmed by biopsy in the women with cancer. RESULTS: At baseline, 35 of the women with cancer (30 percent) and 3 of the control women (3 percent) were positive for HPV DNA (odds ratio, 16.4; 95 percent confidence interval, 4.4 to 75.1). At the time of diagnosis, 80 of the 104 women with cancer for whom tissue samples were available (77 percent) and 4 of the 104 matched control women (4 percent) were positive for HPV DNA. The HPV DNA type was the same in the base-line smear and the biopsy specimen in all of the women with cancer in whom HPV DNA was detected at base line. None of the control women had the same type of HPV in both smears. CONCLUSIONS: A single positive finding of HPV DNA in a Pap smear confers an increased risk of future invasive cervical cancer that is positive for the same type of virus as identified earlier.

Disposition of two tetramethylcyclopropane analogues of valpromide in the brain, liver, plasma and urine of rats.

2,2,3,3-Tetramethylcyclopropane carboxamide (TMCD) and N-methyl TMCD (M-TMCD) are analogues of valpromide (VPD) or amide derivatives of valproic acid (VPA), one of the major antiepileptic drugs (AEDs). In rodent models both TMCD and M-TMCD are more potent as anticonvulsants than VPA. The present study investigates the pharmacokinetics (PK) of TMCD and M-TMCD in rats by monitoring the levels of these two amides in the brain, liver, plasma and urine of rats. The disposition of TMCD and M-TMCD was analyzed in a comparative manner with that of VPD and VPA, previously studied by us. The following similar PK parameters were obtained for TMCD and M-TMCD, respectively: clearance, 5 and 5.6 ml/min/kg; volume of distribution (Vss), 0.72 and 0.96 l/kg; half-life (t1/2), 1.1 and 1. 2 h; and mean residence time (MRT), 2.41 and 2.8 h. The ratio of AUCs of TMCD of liver to plasma and brain to plasma were 1.67 and 1. 13, respectively. The ratios of the AUCs of M-TMCD of liver to plasma and brain to plasma were 1.43 and 0.99, respectively. Thus, both compounds distribute evenly between plasma and brain, but their distribution into the liver is 50% larger than that in the plasma. Therefore, PK analysis of TMCD and M-TMCD brain levels gave major PK parameters similar to those obtained from the plasma data. The fraction metabolized of M-TMCD to TMCD was 32%. The brain was not found to be a metabolic site for the M-TMCD to TMCD biotransformation which occurred primarily in the liver as indicated by the high liver concentrations of TMCD as a metabolite of M-TMCD. Unlike VPD, TMCD and M-TMCD did not undergo amide-acid biotransformation to their corresponding inactive acid, 2,2,3, 3-tetramethylcyclopropane carboxylic acid (TMCA). Both M-TMCD and TMCD distribute better into the brain than VPA, a fact that may contribute to their better anticonvulsant activity.

Glutamatergic activation of hippocampal phospholipase D: postnatal fading and receptor desensitization.

Phospholipase D (PLD) activity was determined in rat hippocampal slices between postnatal days 3 and 35. After birth, basal PLD activity was low and, within 2 weeks, increased to reach a plateau that was maintained up to the adult age. Likewise the response to glutamate developed postnatally to reach a maximum at day 8, but then faded rapidly and was almost absent at day 35. Activation of PLD by 4beta-phorbol 12beta,13alpha-dibutyrate (PDB) was independent of age, whereas the effect of aluminum fluoride (AlF4-) increased to a plateau within the first week. At day 8, PLD stimulation by glutamate via metabotropic receptors involved protein kinase C activation, but was independent of Ca2+ influx; the time course of PLD activation by PDB or AlF4- was linear throughout the experiment, whereas the response to glutamate or 1-aminocyclopentane-1,3-dicarboxylic acid followed a biphasic pattern: the rapid "first phase activation" desensitized within a few minutes and disclosed a small, but maintained "second phase." Pretreatment experiments confirmed desensitization of PLD activation by glutamate, but not by AlF4- or PDB. The biphasic pattern of glutamatergic PLD activation changed during development, i.e., the first phase activation faded and the second phase remained. These results were fully confirmed by the time courses of the PLD-mediated efflux of choline evoked by glutamate. In conclusion, postnatal glutamatergic activation of hippocampal PLD is composed of a pronounced and desensitizing first phase activation and a small, but nondesensitizing second phase. The first, but not the second, phase activation fades rapidly during development. The hypothesis is discussed that the glutamatergic activation of PLD occurs along different pathways in neonate and adult tissue.

The disposition of valproyl glycinamide and valproyl glycine in rats.

PURPOSE: To investigate the disposition of valproyl glycinamide and valproyl glycine in rats and to compare it with that of valproic acid (VPA) and valpromide which were studied previously. METHODS: The study was carried out by monitoring the brain and liver levels of valproyl glycinamide and valproyl glycine (as a function of time after iv dosing) in addition to the regular pharmacokinetic (PK) monitoring of plasma and urine levels of these compounds. RESULTS: The following PK parameters were obtained for valproyl glycinamide and valproyl glycine, respectively: clearance, 7.1 and 16 ml/ min/kg; volume of distribution (Vss), 0.78 and 0.41 l/kg; half-life, 1.1 and 0.37 h; and mean residence time, 1.8 and 0.4 h. The ratios of AUCs of valproyl glycinamide of liver to plasma and brain to plasma were 0.70 and 0.66, respectively. The ratios of the AUCs of valproyl glycine of liver to plasma and brain to plasma were 0.19 and 0.02, respectively. CONCLUSIONS: Valproyl glycinamide distributes better in the brain than VPA, a fact which may contribute to its better anticonvulsant activity. Valproyl glycine was barely distributed in the brain, a fact which may explain its lack of anticonvulsant activity. In addition to the liver, the brain was found to be a minor metabolic site of the biotransformation of valproyl glycinamide to valproyl glycine.

A prospective study on the risk of cervical intra-epithelial neoplasia among healthy subjects with serum antibodies to HPV compared with HPV DNA in cervical smears.

To estimate the risk of developing cervical intra-epithelial neoplasia (CIN) among women exposed to human papillomavirus (HPV) type 16, we performed a prospective study in a population-based cohort of more than 15,000 women followed for 34.9 months. Seventy-four women developed CIN during follow-up and were matched for age, time of sampling and area of residence with 148 women who remained CIN-free during follow-up. The blood samples taken at enrollment were tested for serum antibodies to HPV types 16, 18 and 33 capsids. Cervical smears or biopsies were analyzed for the presence of HPV DNA by nested PCR using HPV general primers and by HPV 16- and 18-type-specific PCR HPV serology and HPV-PCR were in good agreement, particularly when the blood sample and the Pap smear were taken less than 6 months apart. HPV DNA was found in 88% of cases and 4% of controls, whereas HPV 16 DNA was present in 44% of cases and in 1 of 142 controls. HPV-16-seropositive women had a 3-fold increased risk of developing CIN. The risk was highest among women younger than 35 years of age, of whom an estimated 3.4% of HPV-16-seropositive and 0.5% of seronegative women developed CIN. Since the risk associated with HPV-16 seropositivity (a measure of past or present infection) was 35-fold lower than that of HPV DNA (present infection), most infections appear to be eliminated before CIN develops. In conclusion, HPV 16 infection does confer an excess risk of CIN development, and HPV DNA detection has a high predictive value for the presence of high-grade CIN.

Disposition of valpromide, valproic acid, and valnoctamide in the brain, liver, plasma, and urine of rats.

Valpromide (VPD) and valnoctamide (VCD) are amide derivatives of valproic acid (VPA), one of the major antiepileptic drugs (AEDs). In rodent models, both VPD and VCD are more potent as anticonvulsants than VPA. However, in humans, VPD served as a prodrug to VPA, whereas VCD acts as a drug on its own, which is not biotransformed to its corresponding acid--valnoctic acid (VCA). The present study investigates the pharmacokinetics (PKs of VPD and VCD in rats by monitoring the levels of these two amide isomers in the brain, liver, plasma, and urine of rats. The disposition of VPD and VCD was analyzed in a comparative manner with that of VPA. The following PK parameters were obtained for VPD and VCD, respectively: clearance, 6.1 and 3 ml/min/kg; volume of distribution (Vss), 0.63 and 0.58 liter/kg; half-life (t1/2), 42 and 94 min; and mean residence time (MRT), 102 and 196 min. The clearance of VCD in rats was half of that of VPD, and their Vss was similar. Therefore, VCD, t1/2, and MRT were twice as long as those of VPD.PK analysis of VPD and VCD liver and brain levels gave similar major PK parameters to those obtained from the plasma data. VPD underwent hepatic biotransformation to VPA, which persisted in the liver and brain for a longer period than VPD. The fraction metabolized of VPD to VPA was 42%. The brain was not found to be a metabolic site of the VPD-VPA biotransformation. Unlike VPD, VCD did not undergo amid-acid biotransformation to its corresponding acid, but was eliminated by biotransformation to unidentified metabolites. In contrast to VPD and VCD that distributed about evenly between the plasma, liver, and brain, VPA showed different disposition patterns in the plasma, liver, and brain. VCD and VPD distribute better into the brain than VPA, a fact that may contribute to their better anticonvulsant activity.

Dietary effects of barley fibre, wheat bran and rye bran on bile composition and gallstone formation in hamsters.

The effects of brewer's spent grain (BSG), wheat bran and rye bran on bile composition, gallstone formation and serum cholesterol were studied in Syrian golden hamsters. The frequency of gallstone formation in the animals fed diets supplemented with low (10%) and high (20%) concentrations of BSG or wheat bran was significantly lower than that of the animals fed a stone-provoking, fibre-free diet. The ratios of secondary to primary bile acids were lower in the animals fed the diets supplemented with a high dose of BSG, wheat bran and rye bran than in the controls. The ratio of LCA to DCA was reduced only in the animals fed the diet supplemented with rye bran as compared with controls. No significant changes in bile and serum cholesterol levels were observed in the experiment.

Effects of methanol vapor on human neurobehavioral measures.

Methanol could become an important motor fuel. The objective of this exploratory study was to provide preliminary information about whether or not acute exposure to methanol at 250 mg/m3 for 75 minutes would have adverse effects on human neurobehavioral functions important in everyday life. This concentration level was selected because it is at the upper limit of the traffic scenario estimates provided by the U.S. Environmental Protection Agency (EPA)2 (86 to 240 mg/m3), but is below the maximum concentrations for eight-hour average exposures currently recommended by the National Institute of Occupational Safety and Health (NIOSH) and the American Conference of Government and Industrial Hygienists (ACGIH) (260 mg/m3). Although traffic scenario exposure estimates suggest that such high levels of exposure last less than 15 minutes, we used a 75-minute exposure to increase the probability of identifying dependent measures that should be studied in more detail in a future confirmatory study. Twelve healthy young men, each serving as his own control, participated in two sham exposures and two methanol exposures under counterbalanced, double-blind control conditions. Because methanol is present in many foods, and because high preexposure levels of methanol or formate might obscure exposure effects, subjects were required to strictly limit their diets for 12 hours before each experimental session. The following endpoints were examined before, during, and after exposure to methanol and sham vapors: blood and urinary methanol; plasma formate; oral temperature; blood pressure; subjective mood, alertness, fatigue, workload, and symptom scales; spectral analysis of the electroencephalogram; visual- and auditory-event-related potentials; contingent negative variation; respiration; cardiac interbeat interval; Symbol Digit substitution task; three-choice reaction time; Stroop color-word test; simple reaction time; visual function; critical flicker fusion frequency; hand steadiness; visual search task; Gamberale reaction time task; visual tracking task; Sternberg memory task; interval production task; and speeded addition task. Two dual tasks were also included in the task batteries. These endpoints were selected from those indicated in the literature to be sensitive to solvents, and from those that are widely used in other neurobehavioral test batteries to identify the effects of environmental pollutants. Because the number of endpoints examined was large and the number of subjects was small, procedures designed to reduce the number of statistical tests performed were used. Mean methanol concentration in the exposure room during methanol exposures was 249 mg/m3 (SD +/- 7 mg/m3). Exposure produced significant increases in blood and urine methanol concentration. As expected, no changes in plasma formate were observed.(ABSTRACT TRUNCATED AT 400 WORDS)

The influence of barley fibre on bile composition, gallstone formation, serum cholesterol and intestinal morphology in hamsters.

Frequency of gallstones, concentration of bile acids and cholesterol in bile, concentration of cholesterol in serum, and structure of the small intestinal mucosa were analyzed in male Syrian Golden hamsters fed a stone provoking fibre-free diet with or without supplementation of brewer's spent grain (BSG), a concentrated barley fibre source from the by-product of brewing. A significantly lower frequency of gallstones was found in the animals with 10% BSG dietary supplementation. Addition of 30% BSG after an initial 6-week period with a fibre-free, stone provoking diet seemed to dissolve previously formed gallstones. Total bile acid concentration was higher in bile from animals given a diet supplemented with 10% BSG. In addition, the cholesterol concentration in both serum and bile was lower in the 30% BSG supplemented group. Structurally, a 10% BSG supplementation decreased ileal epithelium height whereas a high supplementation (30%) of BSG induced a decrease in epithelial height both of jejunal and ileal mucosa. The results show that BSG has significant effects on the metabolism of bile acids and cholesterol as well as on the morphology of the small intestinal mucosa.

Myoepithelial cells in salivary gland neoplasms.

Archival paraffin sections from normal salivary gland tissue and salivary gland neoplasms were stained by immunoperoxidase technique with a well characterized cytokeratin antibody (PKK1). In normal parotid tissue, myoepithelial cells and peripheral cells of larger ducts were selectively stained. In pleomorphic adenomas, most cells were stained, the staining being somewhat stronger towards the duct lumina. In basal cell adenomas, only cells adjacent to the duct lumina were stained where a differentiation of cells into peripheral and ductal was seen. In adenolymphomas basal cells were stained, and in oncocytomas small elongated cells reacted with the PKK1 antibody. Only a few duct cells in an acinic cell carcinoma were reactive and in mucoepidermoid carcinoma, peripheral epidermoid cells were strongly stained. In adenoid cystic carcinoma, mostly duct cells were stained whereas the peripheral ones remained unstained. Although the intermediate filament protein expression is very stable during tumorigenesis, the staining with the presently used monoclonal antibody in salivary gland neoplasms differed markedly from what could be expected according to current views on the participation of this cell type. This supports our view that cells in tumors should be characterized on the basis of their staining, i.e. state of differentiation and not on their presumed histogenesis.

Long-term carcinogenicity study in Syrian golden hamster of particulate emissions from coal- and oil-fired power plants.

Male Syrian golden hamsters were given 15 weekly intratracheal instillations with suspensions of coal fly ash or oil fly ash. Controls were instilled with saline containing gelatine (0.5 g/100 mL) or to check particle effects with suspensions of hematite (Fe2O3). The common weekly dose was 4.5 mg/hamster. In addition, one subgroup of hamsters was treated with oil fly ash at a weekly dose of 3.0 mg/hamster and another with coal fly ash at a weekly dose of 6.0 mg/hamster. Other groups of hamsters were treated with suspensions of benzo[a]pyrene (BaP) or with suspensions on coal fly ash, oil fly ash, or Fe2O3 coated with BaP. The mass median aerodynamic diameters of the coal and oil fly ashes were 4.4 microns and 28 microns, respectively. Hamsters treated with oil fly ash showed a higher frequency of bronchiolar-alveolar hyperplasia than hamsters in the other treatment groups. Squamous dysplasia and squamous metaplasia were most frequent in animals treated with suspensions of BaP or BaP-coated particles. The earliest appearance of a tumor, the highest incidence of tumors, and the highest incidence of malignant tumors were observed in hamsters treated with oil fly ash coated with BaP. Squamous cell carcinoma and adenosquamous carcinoma were the most frequent malignant tumors. No malignant tumors and only few benign tumors were observed in hamsters instilled with suspensions of fly ash not coated with BaP. The present study gives no indication that coal fly ash could create more serious health problems than oil fly ash.

Advanced gallbladder carcinoma: a case report and review of the literature.

A case with carcinoma of the gallbladder and recurrent metastases to regional lymph nodes is reported. Following primary surgery, secondary resection of node recurrence, and long term combination chemotherapy, the patient is alive and disease free after 9 years. The possibility of a successful cancer suppression, as mirrored by a depressed RES-function test during the treatment with anticancer drugs, is discussed. Only nine other cases with advanced gallbladder cancer and 5 year survival are found in the literature.

Histological types of lung cancer among smelter workers exposed to arsenic.

The histological distribution of lung cancer was investigated in 93 men who had worked at a Swedish smelter with high levels of arsenic. A comparison was made with a group of 136 patients with lung cancer from the county where the smelter was located. Company records provided information on occupational exposure and data on smoking habits were obtained from a next of kin of each subject. No pronounced differences in the histological types of lung carcinomas between smelter workers and the reference group could be seen for smokers. Some analyses indicated an increased proportion of adenocarcinomas among the smelter workers, which confirmed earlier data, but these findings were difficult to interpret. Cases among smelter workers who had never smoked showed a histological distribution resembling that in smokers, indicating that the work environment at the smelter and smoking had a similar influence on the risk for different types of lung cancer.

A comparative study of the acute inhalation toxicity of smoke from TiO2-hexachloroethane and Zn-hexachloroethane pyrotechnic mixtures.

Rats was exposed to white smoke generated from mixtures of titanium dioxide-hexachloroethane (TiO2-HC) and zinc-hexachloroethane (Zn-HC), respectively, in an inhalation chamber operated in the static mode. The dose was varied by varying the amount of smoke mixture and/or the exposure time. The acute inhalation toxicity of TiO2-HC smoke was much lower than the Zn-HC smoke. Thus, the animals survived exposure to TiO2-HC smoke, even at relatively high smoke concentrations. This smoke was irritating to the animals and minor, acute inflammatory changes were seen in lung tissue. In contrast, Zn-HC smoke was very toxic and caused lethal injuries to the experimental animals, even at relatively low concentrations. Pulmonary injuries were extensive and death was due to blood congestion with pulmonary oedema. Since the TiO2-HC and Zn-HC mixtures form TiCl4 and ZnCl2, respectively, a separate study was performed in which rats were exposed to TiCl4 gas or ZnCl2 aerosol. No animals died from exposure to TiCl4 at concentrations between 370 and 2900 mg/m3 for 10 min. The LC50 of ZnCl2 was found to be around 2000 mg/m3 during a 10-min exposure period. The difference between the two types of smoke is explained by the difference in toxicity between TiCl4 and ZnCl2.

Prenatal diagnosis of conjoined twins (diprosopus) with myelomeningocele.

Conjoined twins (diprosopus) with a neural tube defect were diagnosed by ultrasound, alphafetoprotein and acetylcholinesterase in the 18th week of gestation.

Comparison of transbronchial fine needle aspiration biopsy, aspiration of bronchial secretion, bronchial washing, brush biopsy and forceps biopsy in the diagnosis of lung cancer.

The accuracy of morphologic diagnosis from transbronchial fine needle aspirates (TBN), bronchial secretions (BS), bronchial washings (BW), brush biopsy (BB) and forceps biopsy (FB) sampled via a flexible fiberoptic bronchoscope, was studied in 60 malignant lung tumours. In visible tumours the best results were obtained with FB (85%) while TBN was positive in 65%. In cases were bronchoscopy only showed secondary signs of tumour, the sensitivity of FB, BB and TBN was higher than that of BW and aspiration of BS. In tumours not visible through the bronchoscope, the diagnostic accuracy of BB, BW and aspiration of BS was higher than that of FB and TBN. In the diagnosis of carcinoma of the lung the diagnostic accuracy of combining FB and one cytologic method (BW) was higher than that of any of the single methods (p less than 0.05) while no appreciable increase was achieved by using additional methods.