Leishmaniosis mimicking oral neoplasm in a dog: an unusual manifestation of an unusual disease in Finland.
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Biomedical subjects
Publications and source records attributed to M Anttila.
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Avidity of antibodies to Streptococcus pneumoniae type 6B, 14, 19F and 23F polysaccharides (PS) evoked by four different pneumococcal conjugate vaccines was compared. Infants were primed with pneumococcal PS conjugated to the variant diphtheria toxin CRM197 (PncCRM), diphtheria toxoid (PncD), tetanus toxoid (PncT) or meningococcal protein complex (PncOMPC) and boosted with the homologous conjugate or PS vaccine. No booster was given to children in the PncOMPC group. Relative antibody avidity was measured by thiocyanate EIA. No vaccine specific differences were found in avidity of anti-14 or -19F antibodies. By contrast, antibody avidity to 6B and 23F differed significantly between the vaccine groups, PncCRM and PncT inducing antibodies of highest avidity.
One of the recent controversies with substantial clinical interest is the role of HPV in pathogenesis of ovarian cancer. The available highly conflicting data are based on analysis of 175 ovarian carcinomas so far. As an attempt to further elucidate this issue, the first systematic study of HPV detection in ovarian cancer was carried out using a highly sensitive general primer PCR (confirmed by hybridization for low- and high-risk HPV types separately) in a series of 98 histologically and clinically well-characterized epithelial ovarian malignancies. Despite the high (fg) sensitivity and a wide HPV type coverage of the technique used, all 98 ovarian carcinomas failed to demonstrate any signs of HPV DNA whatsoever. The preexisting 12 reports comprising a total of 175 ovarian tumors analyzed for HPV were summarized, giving highly discrepant results (i.e., detection rates from 0 to 100%) with the overall HPV DNA detection rate of 25.7%. The reasons for these discrepant findings are most probably technical. Our data are consistent with those of the majority of the most recent reports failing to disclose HPV DNA in ovarian neoplasia. The present completely negative results make the authors inclined to conclude that HPV is highly unlikely to play any causal role in the pathogenesis of epithelial ovarian neoplasia.
In a randomized study, 20 adult allogeneic BMT recipients were vaccinated at 6 months and 22 at 18 months after BMT with Haemophilus influenzae type b (Hib)-diphtheria toxoid conjugate vaccine (PRP-D), and 23 recipients at 8 months and 21 at 20 months with pneumococcal polysaccharide (Pnc PS) vaccine. IgG1 and IgG2 subclasses of Pnc PS and Hib antibodies and avidities of Pnc PS IgG antibodies were determined by EIA in sera from patients with at least a two-fold total antibody response to Pnc type 3, 6B, 19F or PRP-D. The Pnc PS vaccine induced predominantly IgG1 Pnc 3 antibody production. Anti-Pnc 6B and 19F responses were mainly IgG2. The time of the Pnc PS vaccination, at 8 or 20 months after BMT, did not influence the IgG subclass response pattern. The PRP-D vaccine induced predominantly IgG2 anti-Hib production in the patients vaccinated at 6 months after BMT. The patients vaccinated at 18 months produced IgG1 and IgG2 antibodies more evenly. The same patient was able to produce predominantly IgG1 subclass antibodies to one antigen, Pnc 3, 6B, 19F or Hib, and IgG2 antibodies to another. The avidities of anti-Pnc 6B and 19F 1 month after vaccination were similar to those before vaccination, anti-Pnc 3 avidity was lower than before vaccination but matured in 15 months. The IgG subclass distribution and avidity were similar in the patients with and without chronic GVHD. In conclusion, the IgG response to Pnc type 3 was predominantly IgG1 as in infants and IgG2 to PRP-D, Pnc 6B, and 19F as in adults. Early vaccination after BMT or the presence of chronic GVHD did not impair the quality of response to Pnc PS and PRP-D vaccines.
AIMS: The purpose of this study was to characterize the dose relationship of selegline and desmethylselegiline pharmacokinetics within the selegiline dose range from 5 to 40 mg. METHODS: Eight female subjects, of whom four were using oral contraceptives, ingested a single dose of 5 mg, 10 mg, 20 mg or 40 mg of selegiline HCl in an open four-period randomized study. Concentrations of selegiline and desmethlylselegiline in serum were measured by gas chromatography for 5 h. As it became evident that the use of oral steroids had a drastic effect on selegiline concentrations, the pharmacokinetic analyses were performed separately for oral contraceptive users and those not receiving any concomitant medication. RESULTS: The total AUC and Cmax of selegiline were 10-to 20-fold higher in those subjects taking oral steroids compared with subjects with no concomitant medication; this finding was consistent and statistically significant at all the four dose levels. The dose linearity of selegiline pharmacokinetics failed to be demonstrated in both groups. The AUC and Cmax of desmethylselegiline were only moderately higher (about 1.5-fold; P=NS at each dose level) in the subjects taking oral steroids than in those not receiving concomitant medication. The AUC values of desmethylselegiline increased in a dose linear manner in subjects with no concomitant medication, but not in the oral steroid group. The metabolic ratio (AUC(desmethylselegiline)/AUC(selegiline)) was several-fold lower in the group receiving oral steroids compared with the no-concomitant-medication group (P<0.005 at all the four dose levels). CONCLUSIONS: Concomitant use of oral contraceptives caused a drastic (20-fold) increase in the oral bioavailability of selegiline. The highly significant difference in the metabolic ratio between the groups provides evidence that the mechanism of the interaction between selegiline and female sex steroids involves reduced T-demethylation of selegiline. The present results suggest that concomitant use of selegiline with exogenous female sex steroids should be avoided or the dosage of selegiline should be reduced in order to minimize the risks of selegiline related adverse drug reactions.
The contribution of serotype-specific IgG concentration, subclasses, and avidity to opsonophagocytic activity (OPA) against Streptococcus pneumoniae (Pnc) was evaluated in sera of adults and infants immunized with different pneumococcal vaccines. Antibody concentrations and avidities were measured by enzyme immunoassay (EIA) and OPAs by killing assay of Pnc. The most important factor contributing positively to OPA was the specific IgG level. In infants, a tendency to negative correlation was found between the concentration needed for killing of bacteria and avidity, suggesting that less antibodies of high rather than low avidity were required for killing. No such correlation was seen in adults. However, in adults the avidity was high already before vaccination and the variation was narrow. Thus, avidity was probably not a limiting factor influencing OPA. The effect of IgG2/IgG1 ratio on OPA was mostly negative but insignificant.
The importance of T cells in Chlamydia pneumoniae infection in mice was assessed by comparing wild-type BALB/c mice with nude mice and mice depleted in vivo of either CD4+ or CD8+ T cells. Whereas wild-type mice cleared the primary infection in 3 weeks, nude mice were only able to restrict the infection and could not clear it during the observation period of 56 days. Nude mice exhibited a greater number of macrophages in their lungs and the pulmonary cells secreted a higher level of tumour necrosis factor-alpha (TNF-alpha) than wild-type mice. Depletion of CD4+ cells did not change the overall infection kinetics of the primary infection. However, depletion of CD8+ cells resulted in a slightly impaired clearance of the bacteria in the late stages of primary infection. To assess the role of the two T-cell subsets in the acquired immunity that develops during primary infection in wild-type BALB/c mice, in vivo depletions were performed during reinfection. Prior to reinfection, immunocompetent wild-type mice were infected and natural immunity was allowed to form. During reinfection, depletion of CD4+ cells did not have any effect on infection kinetics, whereas depletion of CD8+ cells abolished the protection, reverting the infection kinetics and bacterial load to the same levels found in wild-type mice during primary infection. These results show that T cells are necessary for clearing C. pneumoniae infection in mice. Furthermore, whereas neither of the two main T-cell subsets, separately, were essential for clearance of primary infection, the induced protective immunity was strongly CD8 dependent.
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BACKGROUND: Rifampin (INN, rifampicin) is a potent inducer of cytochrome P450 (CYP) enzymes involved in drug metabolism and therefore causes many drug interactions. METHODS: The effects of rifampin on the pharmacokinetics of tamoxifen (study I) and toremifene (study II) were examined in 2 randomized, placebo-controlled crossover studies. Ten (study I) or 9 (study II) healthy male volunteers took either 600 mg rifampin or placebo orally once a day for 5 days. On the sixth day, 80 mg tamoxifen or 120 mg toremifene was administered orally. Blood samples were collected up to 336 hours after drug administration. RESULTS: Rifampin reduced the area under the plasma concentration-time curve (AUC) of tamoxifen by 86% (P < .001), peak plasma concentration (Cmax) by 55% (P < .001), and elimination half-life (t1/2) by 44% (P < .001). The AUC of toremifene was reduced by 87% (P < .001), Cmax by 55% (P < .001), and t1/2 by 44% (P < .01) with rifampin. During the rifampin phase, the AUC of N-demethyltamoxifen was 38% (P < .001) and the AUC of N-demethyltoremifene was 20% (P < .01) of that during the placebo phase. CONCLUSIONS: Rifampin markedly reduces the plasma concentrations of tamoxifen and toremifene by inducing their CYP3A4-mediated metabolism. Concomitant use of rifampin or other potent inducers of CYP3A4 with tamoxifen and toremifene may reduce the efficacy of these antiestrogens.
OBJECTIVE: To determine the possible impact of CYP2D6 polymorphism on the pharmacokinetics and pharmacodynamics of selegiline. METHODS: Five poor metabolizers and 8 extensive metabolizers of debrisoquin (INN, debrisoquine) were given 10 mg selegiline hydrochloride. The concentrations of selegiline and its main metabolites in serum were determined for 4 days. The pharmacodynamics were quantitated by measuring platelet monoamine oxidase type B activity for 3 weeks. In addition, the effect of selegiline and its main metabolites on the CYP2D6-catalyzed dextromethorphan O-demethylase activity and the effect of quinidine on the metabolism of selegiline were studied in human liver microsomes. RESULTS: Peak serum concentrations of selegiline were reached rapidly and ranged from 1 to 32 nmol/L. The metabolite concentrations were considerably higher and remained so for a longer period. There were no significant differences in the pharmacokinetic parameters of selegiline, desmethylselegiline, and l-amphetamine between poor metabolizers and extensive metabolizers. However, the area under the serum concentration-time curve (AUC) values of l-methamphetamine were, on average, 46% higher (P = .01) in poor metabolizers than in extensive metabolizers. No significant correlations were found between debrisoquin metabolic ratio and AUC values of selegiline or its metabolites, except for l-methamphetamine (rs = 0.90; P < .001). The maximum monoamine oxidase type B inhibition was 97% in both groups. The inhibitory potency of selegiline, desmethylselegiline, and l-methamphetamine toward dextromethorphan O-demethylase was very low (50% inhibitory concentration values from 160 to 580 mumol/L). Quinidine (< or = 100 mumol/L) did not inhibit the formation of desmethylselegiline or l-methamphetamine from selegiline. CONCLUSIONS: CYP2D6 is not important in the primary elimination of selegiline, and the biological effect of selegiline seems to be similar in poor metabolizers and extensive metabolizers of debrisoquin. The inhibitory effect of selegiline and its main metabolites on CYP2D6 activity seems to be negligible.
Relative avidity of IgG to Streptococcus pneumoniae type 6B and 23F polysaccharides (PSs) was measured in sera of children immunized with pneumococcal vaccines, using an EIA and the chaotropic agent thiocyanate. Infants were immunized at 2, 4, and 6 months of age with pneumococcal PS-diphtheria toxoid conjugate vaccine, and boosted at 14 months with the homologous conjugate or a pneumococcal PS vaccine. The concentrations of antibodies to 6B and 23F PSs increased significantly after the booster with both vaccines. A significant increase in the avidity of anti-6B and anti-23F antibodies was seen after the booster with conjugate but not with PS vaccine. Avidity also increased in another group of infants primed and boosted with pneumococcal PS-meningococcal protein conjugate but not in a group boosted with PS vaccine after priming with pneumococcal PS-tetanus toxoid conjugate. In the latter group, however, the avidity of anti-6B was high before boosting.
BACKGROUND: Specific and selective alpha2-adrenergic drugs are widely exploited in veterinary anesthesiology. Because alpha2-agonists are also being introduced to human practice, the authors studied reversal of a clinically relevant dexmedetomidine dose with atipamezole, an alpha2-antagonist, in healthy persons. METHODS: The study consisted of two parts. In an open dose-finding study (part 1), the intravenous dose of atipamezole to reverse the sedative effects of 2.5 microg/kg of dexmedetomidine given intramuscularly was determined (n = 6). Part 2 was a placebo-controlled, double-blinded, randomized cross-over study in which three doses of atipamezole (15, 50, and 150 microg/kg given intravenously in 2 min) or saline were administered 1 h after dexmedetomidine at 1-week intervals (n = 8). Subjective vigilance and anxiety, psychomotor performance, hemodynamics, and saliva secretion were determined, and plasma catecholamines and serum drug concentrations were measured for 7 h. RESULTS: The mean +/- SD atipamezole dose needed in part 1 was 104+/-44 microg/kg. In part 2, dexmedetomidine induced clear impairments of vigilance and psychomotor performance that were dose dependently reversed by atipamezole (P < 0.001). Complete resolution of sedation was evident after the highest (150 microg/kg) dose, and the degree of vigilance remained high for 7 h. Atipamezole dose dependently reversed the reductions in blood pressure (P < 0.001) and heart rate (P = 0.009). Changes in saliva secretion and plasma catecholamines were similarly biphasic (i.e., they decreased after dexmedetomidine followed by dose-dependent restoration after atipamezole). Plasma norepinephrine levels were, however, increased considerably after the 150 microg/kg dose of atipamezole. The pharmacokinetics of atipamezole were linear, and elimination half-lives for both drugs were approximately 2 h. Atipamezole did not affect the disposition of dexmedetomidine. One person had symptomatic sinus arrest, and another had transient bradycardia approximately 3 h after receiving dexmedetomidine. CONCLUSIONS: The sedative and sympatholytic effects of intramuscular dexmedetomidine were dose dependently antagonized by intravenous atipamezole. The applied infusion rate (75 microg x kg(-1) x min(-1)) for the highest atipamezole dose was, however, too fast, as evident by transient sympathoactivation. Similar elimination half-lives of these two drugs are a clear advantage considering the possible clinical applications.
Cell-mediated immune (CMI) responses play a major role in protection as well as pathogenesis of many intracellular bacterial infections. In this study, we evaluated the infection kinetics and assessed histologically the lymphoid reactions and local, in vitro-restimulated CMI responses in lungs of BALB/c mice, during both primary infection and reinfection with Chlamydia pneumoniae. The primary challenge resulted in a self-restricted infection with elimination of culturable bacteria by day 27 after challenge. A mild lymphoid reaction characterized the pathology in the lungs. In vitro CMI responses consisted of a weak proliferative response and no secretion of gamma interferon (IFN-gamma). The number of lung-derived mononuclear cells increased substantially during the primary infection; the largest relative increase was observed in B cells (B220(+)). After reinfection, the number of lung-derived mononuclear cells increased further, and the response consisted mainly of T cells. The reinfection was characterized in vivo by significant protection from infection (fewer cultivable bacteria in the lungs for a shorter period of time) but increased local lymphoid reaction at the infection site. In vitro, as opposed to the response in naive mice, acquired immunity was characterized by a strongly Th1-biased (IFN-gamma) CMI response. These results suggest that repeated infections with C. pneumoniae may induce Th1-type responses with similar associated tissue reactions, as shown in C. trachomatis infection models.
PURPOSE: To analyze alpha-catenin and collagen IV expression in epithelial ovarian cancer with special reference to their prognostic significance and correlations with clinical and pathologic characteristics, as well as cell proliferation marker Ki-67. PATIENTS AND METHODS: Alpha-catenin, collagen IV, and Ki-67 expression was immunohistochemically analyzed in paraffin-embedded specimens of 316 patients with epithelial ovarian cancer. RESULTS: Alpha-catenin and collagen IV expression was not interrelated or related to International Federation of Gynecology and Obstetrics (FIGO) stage or proliferation marker Ki-67. Alpha-catenin expression was reduced (< 100%) in 50% of primary tumors. Reduced alpha-catenin and collagen IV expression was directly related to high histologic grade (P < .001). In both univariate and multivariate analyses, Ki-67 proliferation significantly predicted overall survival. In the subset of 86 patients with stage I tumor, a reduced (< 100%) alpha-catenin expression approached statistical significance as a negative prognostic factor (P = .035) and retained its statistical significance in the multivariate analysis (P = .025). The low (< 30%) expression of alpha-catenin (n = 10) was a sign of inferior survival as compared with normal expression in both the univariate (P = .0107) and multivariate analyses (P = .0105). CONCLUSION: Alpha-catenin expression seems to be a useful marker of those FIGO stage I tumors likely to run a less favorable course. The high cell proliferative activity was associated with poor survival. In the future, alpha-catenin and Ki-67 expression should be studied in a large prospective cohort that includes early-stage cancers to select the more aggressive tumors for intense early chemotherapy.
In this pharmacokinetics study, concentrations of toremifene (TOR), a new antiestrogen, were measured after a 7-day oral treatment in serum, lung, and tumor tissue to determine the optimal dose of TOR for the modulation of clinical multidrug resistance in patients with lung cancer. Target levels of the antiestrogen were based on previous in vitro studies. Altogether, 18 patients with operable lung tumors were studied. TOR was given in an open, nonrandomized, phase I study at three different dose levels. The medication consisted of oral TOR given for 7 days at either 240, 480, or 600 mg/day before surgical removal of the tumor. At least five patients were scheduled to be included at each dose level, with all five receiving the full course of therapy before escalation of the dose. Blood samples for serum TOR concentration measurements were taken on days 0 and 7. Specimens of tumor and normal lung tissue of approximately 0.5 g were taken on day 7. The concentrations of TOR and its metabolites were determined in serum, lung, and tumor tissue at different dose levels. Altogether, 12 evaluable patients completed the scheduled treatment. The concentrations measured in serum, lung, and tumor tissue increased along with the dose used, such that the highest TOR values were achieved at 600 mg/day, with mean values being 4.9 mumol/l, 175.0 mumol/g, and 122.7 mumol/g, respectively. The concentrations of TOR and its metabolite N-demethyltoremifene were highest in lung tissue, but the values measured in tumor specimens were also well above the respective concentrations detected in serum samples. The TOR doses of 240 and 480 mg/day were well tolerated. One patient in the group treated at 600 mg/day had to discontinue the treatment because of headache and nausea. TOR given at doses ranging from 480 to 600 mg/day for 7 days will produce serum, lung, and tumor concentrations of the parent drug and its metabolites that have been shown to reverse multidrug resistance of cancer cells in vitro. As the 480-mg/day dose of TOR produced tumor concentrations high enough to reverse multidrug resistance without producing adverse drug reactions, the dose recommended for the foreseen clinical trials in the reversal of multidrug resistance would be 480 mg/day for 7 days.
Toremifene (Fareston)-a novel antiestrogenic drug with a triphenylethylene structure-is effective in the treatment of postmenopausal breast cancer patients. It can be safely given even at high doses of up to 300 mg/day. The purpose of the present study was to investigate the effect and tolerability of high-dose toremifene in the treatment of patients with advanced renal-cell carcinoma (RCC). A total of 36 patients started treatment with toremifene at 300 mg/day, including 26 men and 10 women. Their mean age was 56 years (range 35-75 years). In all, 19 patients were nephrectomized. One patient was not evaluable for response because of insufficient treatment time. The response rate was 17%, including one complete response (CR, 3%) lasting for 121+ weeks and five partial responses (PRs, 14%) with a mean duration of 40+ weeks. Ten cases of no change (NC, 28%) had a mean duration of 24 weeks. There was no significant difference in the response rate when patients with lung metastases alone were compared with patients showing metastases of other sites with or without lung metastases. Total pain control was achieved in 45% of the patients who had pain at the beginning of the treatment, and partial control was attained in 20%. Ten patients (28%) developed adverse reactions, which led to discontinuation of the treatment in one case. Blood samples were taken from 16 patients on days 0, 1, 3, 7, 14, and 28 for drug analyses. The concentration of toremifene and its main metabolites measured in serum were about 1.5 times that detected after a conventional dose of 60 mg/day. It can be concluded that high-dose toremifene is an effective and safe palliative treatment in advanced RCC.
We have evaluated the risk for pharmacokinetic and/or pharmacodynamic interactions of concomitantly administered selegiline, a selective monoamine oxidase type B inhibitor, and citalopram, a widely used selective serotonin uptake inhibitor antidepressant. Two parallel groups of healthy volunteers received 20 mg of citalopram (n = 12) or placebo (n = 6) once daily for 10 days in a randomized, double-blind fashion, followed by concomitant selegiline 10 mg once daily for 4 days. The safety of this drug combination was assessed by measurements of blood pressure, heart rate, body temperature, and inquiries for adverse events. Blood samples were taken for the analysis of serum concentrations of both study drugs and their metabolites and plasma prolactin, adrenaline, noradrenaline, and 3,4-dihydroxyphenylglycol (DHPG); urinary excretion of serotonin and 5-hydroxyindoleacetic acid (5-HIAA) were assessed. After a 5-week washout, the 12 subjects who took citalopram in the first part of the study received 10 mg of selegiline once daily for 4 days to compare the pharmacokinetics of selegiline with and without concomitant citalopram. The safety analysis showed no significant differences in vital signs or the frequency of adverse events between the study groups. Plasma prolactin concentrations were increased by 40% after 10 days' treatment with citalopram (p = 0.03); this was not potentiated by concomitantly administered selegiline. The comparison of plasma concentrations of noradrenaline, adrenaline, and DHPG and the amount of serotonin and 5-HIAA excreted into urine between the study groups indicated no signs of subclinical pharmacodynamic interaction between selegiline and citalopram. The relative bioavailability of selegiline was slightly reduced (by 29%; p = 0.008) when citalopram was coadministered compared with selegiline alone. However, no indication of a pharmacokinetic interaction was found in the analysis of serum concentrations of the three main metabolites of selegiline. The pharmacokinetics of citalopram remained unaffected by concomitant selegiline. The present results indicate lack of clinically relevant pharmacodynamic or pharmacokinetic interactions between selegiline and citalopram.