Attitudes towards individuals with halitosis: an online cross sectional survey of the Dutch general population.

OBJECTIVE: To derive an estimate of encounters with halitosis and to assess the impact of halitosis on their psychosocial interactions with halitosis patients. METHODS: Participants were 1,006 members of an online panel, being representative of the population of the Netherlands with regard to gender, age, family situation, education level and labour participation. They were invited to participate in a survey using an online questionnaire with four questions on becoming faced with people having halitosis. RESULTS: Almost 90% of the participants indicated being faced with a person having halitosis regularly, 40% at least once a week, and men significantly more frequently than women. Halitosis was reported to be a strong 'downer' when meeting a person for the first time. Whether one would draw a person's attention to his breath malodour proved to be related to the kind of person involved and appeared to decrease with the increase of the social distance to the person. Drawing a person's attention to his breath malodour would virtually always be performed personally. CONCLUSION: Halitosis is considered to be one of the most unattractive aspects of social interactions and has potentially damaging effects on psychosocial interactions and relationships.

[Self-perceived oral odour and social interaction]. / Subjectieve mondgeurperceptie en sociaal functioneren.

This study examined the influence of self-perceived oral odour on social interaction. A representative sample of 1,082 people from the Dutch population of 16 years and older, were surveyed. On average, the participants graded their oral odour as 66.8 on a scale 0-100; 4.2% judged their oral odour as 'not fresh' (score < or = 30). Approximately 65% indicated that they took into account the fact that, when meeting somebody for the first time, that person might smell their oral odour. Participants judging their oral odour to be not fresh were shown to keep significantly more distance when meeting somebody than participants judging their oral odour as fresh. Noteworthy was a subgroup of participants who judged their oral odour as fresh, but indicated that they always kept a certain distance to other people. The results suggest that self-perceived oral odour is a potential barrier in social interaction.

[Psychosocial aspects of halitosis]. / Psychosociale aspecten van halitose.

Using a representative sample from the Dutch population, some psychosocial aspects of halitosis were examined. The results of the survey showed that almost 90% of the Dutch population aged 16 years and older were regularly faced with halitosis. Forty percent reported to be exposed to someone with halitosis at least once a week, men significantly more frequently than women. Although less strongly than body odour, halitosis was reported as being one of the most severe 'let-downs' in social interactions. The greater the social distance between subjects, the less likely is the chance that a person's attention will be drawn to halitosis experienced. When it comes to an unknown person, the chance was no more than 7%, suggesting that it is problematic to draw a person's attention to the presence of halitosis. Considering the potential social consequences of halitosis is it important that dentists and dental hygienists draw patients' attention to the presence of halitosis, when this is the case, thereby encouraging them to seek adequate treatment.

Long-term follow-up of leukaemia patients after related cryopreserved allogeneic bone marrow transplantation.

We have previously shown that allogeneic bone marrow transplantation (BMT) with cryopreserved donor marrow cells can be used without prolonging the engraftment time or interfering with the reconstitution of haemopoiesis. In this report we extend our initial observations of the first 40 patients who underwent allogeneic bone marrow transplantation from related donors with cryopreserved donor bone marrow for haematological malignancies, including the long-term follow-up data of the previously reported patients. The outcome of these patients was compared with that of 40 related BMT recipients receiving fresh donor bone marrow (historic control group). Time until engraftment of all patients receiving cryopreserved bone marrow was not different from the control group (ANC > 0.5 x 10(9)/l 17d (range 11-24 d) versus 17.5 d (range 10-28 d): platelets > 20 x 10(9)/l 21 d (range 11-85 d) versus 22 d (range 13-69 d), respectively). There was the same incidence of acute and chronic GvHD in patients receiving either cryopreserved bone marrow or fresh bone marrow (acute GvHD > or = II 61% v 60% and chronic GvHD 56% v 52%, respectively). Chimaerism studies showed no difference between the patient groups. Furthermore, the two groups did not differ in day 100 survival (82% v 72%). With a median follow-up of 520 d (range 47-1365 d) and 1289 d (range 48-1849 d), 60% of the patients receiving cryopreserved and 53% of the patients receiving fresh allogeneic donor bone marrow, respectively, are alive. We conclude that cryopreservation of allogeneic related donor bone marrow does not adversely affect engraftment, does not decrease the incidence of severe acute GvHD, and does not seem to affect the day 100 survival or long-term haemopoiesis.

An overview of successful TGEV vaccination strategies and discussion on the interrelationship between TGEV and PRCV.

Porcine respiratory coronavirus (PRCV) is a new variant of TGE with an altered pathogenesis. PRCV multiplies mainly in tonsilar tissues and the respiratory tract. There are no enteric symptoms and in experimentally infected pigs, even the respiratory tract infection is usually asymptomatic. PRCV is spread aerogenically through herds and the significance of PRCV as a pathogen in swine has yet to be determined. Despite the differences in pathogenesis and tissue tropism, the behavior of TGEV and PRCV are closely related antigenically. PRCV induces an antibody response in pigs that cannot be distinguished from TGEV-infected pigs by conventional serological assays. PRCV sensitized animals are not protected from TGEV challenge nor is the milk antibody provided to nursing piglets completely effective in prevention of TGEV infections; thus PRCV is not a good vaccine candidate for TGEV infections. PRCV subclinical infections have led to several reported cases of enzootic TGEV in herds that had been diagnosed as TGEV immune strictly on the basis of serum neutralizing titers which were later found to be due to exposure to PRCV. Vaccination studies conducted with the Ambico, oral modified live TGEV vaccine have led to some startling new results: (1) Use of Ambico TGEV modified live vaccine has been shown to provide complete protection against subsequent PRCV challenge and (2) the effectiveness of TGEV vaccination is actually enhanced by previous exposure to PRCV (3) Weanling pigs which have passively acquired circulating TGEV neutralizing antibodies are protected from subsequent PRCV infections.

Methylazoxyprocarbazine, the active metabolite responsible for the anticancer activity of procarbazine against L1210 leukemia.

Procarbazine is a 1,2-disubstituted hydrazine derivative that is used to treat human leukemias. The anticancer activity of procarbazine results from bioactivation to reactive intermediates. It is first oxidized to azoprocarbazine and further N-oxidized to a mixture of methylazoxyprocarbazine and benzylazoxyprocarbazine isomers. In this study the azoxyprocarbazine isomers were synthesized and purified. The cytotoxic effect of the metabolites on the L1210 murine leukemia cell line were then evaluated in vitro by use of a colorimetric assay using 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl-tetrazolium bromide. The results of this study showed that the methylazoxyprocarbazine isomer was the most cytotoxic metabolite (IC50, 0.2 mM). The benzylazoxy isomer had an insignificant cytotoxic effect, and a mixture of the two isomers was intermediate in effectiveness. This assay, however, could not be used to determine the cytotoxicity of procarbazine since the drug itself (not the live cells) reduced the dye. A soft-agar clonogenic assay demonstrated that procarbazine was cytotoxic only at higher concentrations (IC50, 1.5 mM) than methylazoxyprocarbazine (IC50, 0.15 mM). The effect of procarbazine and its metabolites on the survival of L1210 tumor-bearing mice was determined, and methylazoxyprocarbazine was again the most effective compound. These studies demonstrate that the methylazoxyprocarbazine metabolite is probably the major cytotoxic intermediate involved in the mechanism of anticancer action of procarbazine.

Separate mechanisms for procarbazine spermatotoxicity and anticancer activity.

Procarbazine causes dose-dependent decreases in sperm count after a single i.p. injection in (C57BL/6 X DBA/2)F1 male mice. Two antioxidants, N-acetylcysteine and sodium ascorbate, administered with equimolar doses of procarbazine decreased the spermatotoxicity of procarbazine. At the highest doses of procarbazine (400 mg/kg) that caused a 56% decrease in sperm count, equimolar doses of N-acetylcysteine coadministered with procarbazine caused only a 17% decrease in sperm count, and equimolar doses of ascorbate coadministered with procarbazine caused only a 13% decrease in sperm count. Thus, protection against the spermatotoxic effects of procarbazine was demonstrated with either antioxidant. The effect of the antioxidants on the chemotherapeutic efficacy of procarbazine against murine L1210 leukemia was also assessed. Procarbazine at the highest dose (600 mg/kg) increased mean survival time of mice inoculated i.p. with 1 X 10(5) L1210 leukemia cells by 31%. Simultaneous administration of equimolar doses of either N-acetylcysteine or ascorbate given with procarbazine caused no change in the increased mean survival time of tumor-bearing mice. These results indicate a decrease in the toxicity of procarbazine when coadministered with antioxidants, via decreased spermatotoxicity without changing anticancer efficacy. The results also indicate that different mechanisms are involved in the spermatotoxicity and anticancer activity of procarbazine.

Procarbazine spermatogenesis toxicity: deuterium isotope effects point to regioselective metabolism in mice.

Procarbazine was shown to decrease spermatogenesis in male mice in a dose-dependent manner. Significant decreases (44% of controls) in spermatogenesis were observed when a dose of 400 mg/kg was administered 18 days prior to determination of sperm count. Procarbazine caused no significant acute spermatocidal activity in vivo. Procarbazine-associated decreases in spermatogenesis were thus used as an index of toxicity to developing spermatid cells. Procarbazine analogs were synthesized that had deuterium substituted for hydrogen at the benzylic position, N-isopropyl-alpha-(2-methylhydrazino)-p-[alpha, alpha-2H2]toluamide (d2-procarbazine), or at the methyl position, N-isopropyl-alpha-(2-[alpha, alpha, alpha-2H3]methylhydrazino)-p-toluamide (d3-procarbazine). Spermatogenesis decreases caused by d3-procarbazine were essentially the same as with procarbazine in mice (66% of controls at a dose of 200 mg/kg), but d2-procarbazine was nontoxic to developing sperm cells (99% of control at a dose of 200 mg/kg). The decrease in toxicity caused by deuterium substitution at the benzylic position, coupled with the absence of an effect with the methyl-labeled analog, indicate the requirement for regioselective oxidative metabolism of procarbazine at the benzylic position prior to the toxic event.