Immunological findings in patients with chronically recurrent vaginal candidosis and new therapeutic approaches

Boundary-anchored neural mechanisms of location-encoding for self and others

Everyday tasks in social settings require humans to encode neural representations of not only their own spatial location, but also the location of other individuals within an environment. At present, the vast majority of what is known about neural representations of space for self and others stems from research in rodents and other non-human animals^1-3. However, it is largely unknown how the human brain represents the location of others, and how aspects of human cognition may affect these location-encoding mechanisms. To address these questions, we examined individuals with chronically implanted electrodes while they carried out real-world spatial navigation and observation tasks. We report boundary-anchored neural representations in the medial temporal lobe that are modulated by one's own as well as another individual's spatial location. These representations depend on one's momentary cognitive state, and are strengthened when encoding of location is of higher behavioural relevance. Together, these results provide evidence for a common encoding mechanism in the human brain that represents the location of oneself and others in shared environments, and shed new light on the neural mechanisms that underlie spatial navigation and awareness of others in real-world scenarios.

Investigations by cell-mediated immunologic tests and therapeutic trials with thymopentin in vaginal mycoses

Objective: According to unsatisfactory therapeutic results in patients with chronically recurrent vaginal candidosis, we investigated if immunologic patient factors could be found and treated.

Methods: In 42 women with chronically recurrent and 20 women with acute Candida albicans vulvovaginitis, as well as 14 women with C. glabrata vaginitis, the following investigations were carried out: identification of yeast species; quantification of T lymphocytes and their subpopulations in sera; proliferation tests of T lymphocytes in vitro; treatment of 18 patients with chronically recurrent vaginal candidosis with the synthetic T-lymphocyte- stimulator thymopentin; and, finally, control of the above-mentioned parameters in the clinical course.

Results: Women with C. albicans vulvovaginitis showed fewer T lymphocytes and subpopulations in the peripheral blood than healthy women. Only the number of non-specific killer (NK) cells, however, was significantly lower in cases of acute C. albicans vulvovaginitis. In women with C. glabrata vaginitis, the number of T lymphocytes in the blood was within the normal range. In vitro proliferation tests using mitogens, bacterial antigens, and commercially available candida antigens with and without addition of thymopentin were carried out on the T lymphocytes of women with chronically recurrent C. albicans vulvovaginitis. These tests revealed no significant differences compared with the other patients with C. albicans infections. The patients were treated with thymopentin. Those women who revealed an increase of initially low numbers of T-helper cells recovered from vaginal candidosis after thymopentin treatment.

Conclusions: The peripheral T lymphocytes may be diminished in patients with chronically recurrent C. albicans vaginitis, and immunologic treatment can reduce the relapse rate.

Stress as a cause of chronic recurrent vulvovaginal candidosis and the effectiveness of the conventional antimycotic therapy

Chronic Candida vulvovaginitis cannot, at present, be treated effectively with local or oral antimycotic medication. Göttlicher & Meyer [Vulvovaginalmykose. Klinische Ergebnisse einer epidemiologischen Langzeitstudie, Thieme, Stuttgart (1998); Mycoses41 (1998) 49] formulated a hypothesis to explain this fact. They say that stress is the main cause of vulvovaginal mycosis, and that frequently cited predisposing somatic risk factors are not causing the illness. Two research projects were carried out to test this hypothesis. The first project was conceived to provide direct evidence for two empirical statements derived from the Göttlicher-Meyer hypothesis: (i) stress as a predictor of vulvovaginitis is least valid as the commonly assumed somatic factors and (ii) combinations of factors that reliably discriminate index women from symptom-free women point to aspects of psychosocial development, particularly stress, and not to somatic factors. Between March and November 1999, 309 successive patients were randomly chosen from those successively treated in one in-patient and two out-patient settings. Of those chosen, 117 had had at least one episode of vaginal candidosis within the 2 years prior to enlistment in the study. The remaining 192 patients had experienced no such illness. For the 117 index patients both of the above empirical statements were confirmed by statistical analyses. The second project was designed to test predictions concerning the ineffectiveness of traditional antimycotic treatment derived from the Göttlicher-Meyer hypothesis. Three different empirical statements were derived from the hypothesis--each based on the assumption of a Poisson distribution of relapses that remains uninfluenced by treatment attempts. Each of the statements was tested and confirmed in independent samples--the first in the sample used in project one, the second in a sample of 206 women insured by public Healths Management Organizations (HMOs) and the third in a sample of 179 women insured by private HMOs. Each patient had evidenced Candida albicans vulvovaginitis at least once in the time interval between 1996 and 2000. Statistical analyses confirmed each of the empirical statements, thereby substantiating the Göttlicher-Meyer hypothesis. The authors conclude that (i) psychosocial factors, particularly stress, are the primary causes of Candida albicans vulvovaginitis. Accompanying somatic factors are of little statistical significance in explaining occurrence and relapse. (ii) Traditional antimycotic treatment influences only the symptoms of the illness, not its causes, and has no effect on the probability of a relapse. Increased treatment effectiveness can be achieved only at the cost of a complete re-orientation concerning the causes of vaginal mycosis. Interventions designed to strengthen the patients' immune response are among the most promising.

Women with recurrent vaginal candidosis have normal peripheral blood B and T lymphocyte subset levels

OBJECTIVE

To compare the B and T lymphocyte subset levels of otherwise healthy women suffering from frequently recurrent vaginal candidosis with a healthy control group.

SUBJECTS

26 unselected otherwise healthy women of reproductive age with at least four attacks of vaginal candidosis in the past year and more than three vaginal isolates of a moderate or heavy growth of Candida albicans. Controls were 26 patients or clinical and laboratory staff (asymptomatic for genital infection) matched for time of day and age within 5 years. Only three patients accepted an HIV test. All proved HIV negative. No controls were tested.

MAIN OUTCOME MEASURES

T lymphocyte subsets (CD4 and 8) and B lymphocytes (CD 19) as estimated from the total lymphocyte count and flow cytometry.

RESULTS

No statistically significant difference between patients and controls.

CONCLUSION

No significant difference was found between patients and controls in levels of lymphocyte subsets.

Immunological investigations in vaginal mycoses

In 42 women with chronically recurrent and 20 women with acute Candida albicans vulvovaginitis, as well as 14 women with Candida glabrata vaginitis, the following investigations were carried out: determination of protein content and secretory immunoglobulin A (sIgA) in the cervicovaginal secretion by a self-modified ELISA technique; determination of immunocells and cellbound IgA in the cervicovaginal secretion by immunofluorescence and nephelometric analysis of IgA in the serum. The results were compared with those of 77 pre-menopausal non-pregnant women with or without intake of anti-ovulants, 17 healthy pregnant women and four hysterectomised pre-menopausal women. Due to inflammation, women with acute and chronically recurrent Candida albicans vulvovaginitis had a higher protein content in the cervicovaginal secretion than healthy women. However, the content of secretory IgA was not increased but even slightly decreased in chronic cases. The number of macrophages and granulocytes in the vaginal content was not increased compared with healthy patients. In only a few cases was IgA detected on yeast cells and in the cervicovaginal secretion by fluorescence microscopy. In chronically-relapsing vaginal candidosis, the frequency of the serotype B of C. albicans was strikingly high. Women with Candida glabrata vaginitis showed lower values of secretory sIgA in the vaginal secretion compared with healthy patients as well as women with vaginitis caused by C. albicans. However, like healthy women, they had normal protein values in the cervicovaginal secretion and also lower values of IgA in the serum compared with women of C. albicans vulvovaginitis patients. Macrophages and granulocytes were demonstrable in the cervicovaginal secretion just as in healthy persons. Women with C. glabrata vaginitis showed a more conspicuous, although not a significantly more frequent, binding of IgA to budding cells demonstrated by fluorescence microscopy than women with C. albicans.

Enzymatic cleavage of thymopoietin oligopeptides by pancreatic and intestinal brush-border enzymes

The intestinal enzymatic degradation of the immunomodulating peptides thymotrinan (TP3), thymocartin (TP4), and thymopentin (TP5), three oligopeptides derived from the naturally occurring thymus hormone thymopoietin, was investigated to evaluate their potential for peroral drug delivery. In the presence of brush-border membrane vesicles, crude pancreas extract and everted rings from duodenum, jejunum, ileum, and colon, all peptides were shown to be degraded both by pancreatic enzymes and brush-border aminopeptidases. Degradation clearances (Cldeg) of TP3, TP4, and TP5 were calculated for a quantitative comparison of peptide stability. In the presence of crude pancreas extract, there was a rapid degradation of TP5 (Cldeg 17.9 ml/min) in comparison with TP3 and TP4 (Cldeg 0.95 and 0.56 ml/min, respectively, at 0.2 mM peptide concentration) caused by the cleavage of the C-terminal tyrosine by carboxypeptidase A, whereas TP3 and TP4 underwent hydrolysis by aminopeptidase N. In the presence of brush-border membrane vesicles, the degradation clearances were 3.9, 3.1, and 2.4 ml/min at 0.2 mM concentrations of TP4, TP5, and TP3, respectively. The clearance of all peptides was lowered with increasing peptide concentrations, indicating saturable degradation processes. The degradation of the thymopoietin oligopeptides in the presence of brush-border membrane enzymes was exclusively catalyzed by aminopeptidase N. The degradation of all peptides was highly dependent on the intestinal segment, with the lowest degradation clearance observed in the colon.

Production and function of cytokines in natural and acquired immunity to Candida albicans infection

Host resistance against infections caused by the yeast Candida albicans is mediated predominantly by polymorphonuclear leukocytes and macrophages. Antigens of Candida stimulate lymphocyte proliferation and cytokine synthesis, and in both humans and mice, these cytokines enhance the candidacidal functions of the phagocytic cells. In systemic candidiasis in mice, cytokine production has been found to be a function of the CD4+ T helper (Th) cells. The Th1 subset of these cells, characterized by the production of gamma interferon and interleukin-2, is associated with macrophage activation and enhanced resistance against reinfection, whereas the Th2 subset, which produces interleukins-4, -6, and -10, is linked to the development of chronic disease. However, other models have generated divergent data. Mucosal infection generally elicits Th1-type cytokine responses and protection from systemic challenge, and identification of cytokine mRNA present in infected tissues of mice that develop mild or severe lesions does not show pure Th1- or Th2-type responses. Furthermore, antigens of C. albicans, mannan in particular, can induce suppressor cells that modulate both specific and nonspecific cellular and humoral immune responses, and there is an emerging body of evidence that molecular mimicry may affect the efficiency of anti-Candida responses within defined genetic contexts.

Vaginal yeast flora of pregnant women in the Cusco region of Peru

A study of the vaginal yeast flora in pregnant women living in Cusco and in its region (Peru), located approximately 3000 m above sea level, is reported. We observed 300 pregnant, healthy and non-diabetic women who attended a gynaecological clinic in the Lorena, Regional or IPSS (Instituto Peruano de Seguridad Social) hospitals in Cusco. A comprehensive clinical history was obtained from each patient. It included age, work, parity, time of pregnancy, use of contraceptives or antibiotics, type of vaginal symptoms, type and amount of vaginal secretion. The yeasts were isolated from 44.3% of the cases. The positive cases were more frequently found in the following categories: 20-30 year-old patients (69.2%), ninth month of pregnancy (49.6%), first pregnancy (41.4%), no delivery (58.7%) and no abortion (66.9%). Most women complained of leukorrhea (75.9%) with mucus, scarce without odour (18.8%) or lumpy, regular, without odour (15.8%) secretion. The yeasts isolated were Candida albicans (66.2%), other Candida species (12.8%), Torulopsis glabrata (8.3%) or other Torulopsis species (2.2%), Saccharomyces cerevisiae (7.5%), Rhodotorula sp. (1.5%) and Trichosporon cutaneum (1.5%).