PGL-1 and LID-1 antibody levels in HIV-infected and HIV-uninfected individuals in a Hansen's disease (leprosy) endemic area of Brazil.

Serological tests for subclinical Mycobacterium leprae infection based on antibodies to phenolic glycolipid-1 (PGL-1) and leprosy IDRI diagnostic-1 (LID-1) have not been compared in HIV-infected and uninfected individuals. PGL-1 seropositivity by ELISA was 6.0 % (21/350) in HIV-infected compared with 29.1 % (102/350) in HIV-uninfected individuals (p < 0.001); LID-1 seropositivity was 45.4 % (159/350) in HIV-infected compared with 50.3 % (153/304) in HIV-uninfected individuals (p = 0.21). In HIV-infected individuals, LID-1 but not PGL-1 antibody levels were inversely associated with CD4+ cell count (p = 0.02). These differential associations of HIV infection and CD4 count with PGL-1 and LID-1 have implications for M leprae immunodiagnostic tools and require replication.

Analysis of ribosomal RNA stability in dead cells of wine yeast by quantitative PCR.

During wine production, some yeasts enter a Viable But Not Culturable (VBNC) state, which may influence the quality and stability of the final wine through remnant metabolic activity or by resuscitation. Culture-independent techniques are used for obtaining an accurate estimation of the number of live cells, and quantitative PCR could be the most accurate technique. As a marker of cell viability, rRNA was evaluated by analyzing its stability in dead cells. The species-specific stability of rRNA was tested in Saccharomyces cerevisiae, as well as in three species of non-Saccharomyces yeast (Hanseniaspora uvarum, Torulaspora delbrueckii and Starmerella bacillaris). High temperature and antimicrobial dimethyl dicarbonate (DMDC) treatments were efficient in lysing the yeast cells. rRNA gene and rRNA (as cDNA) were analyzed over 48 h after cell lysis by quantitative PCR. The results confirmed the stability of rRNA for 48 h after the cell lysis treatments. To sum up, rRNA may not be a good marker of cell viability in the wine yeasts that were tested.

A morphometric and immunohistochemical study of melanocytes in periorbital hyperpigmentation.

BACKGROUND: An increase in number of melanocytes in the basal cell layer of the epidermis is an important feature in many disorders of hyperpigmentation. In this study, we attempted an objective evaluation of the linear density of melanocytes and keratinocytes, along with other epidermal characteristics, in periorbital hyperpigmentation using immunohistochemistry and morphometric techniques. METHODS: Melanocytes and epidermal parameters were assessed by digital morphometry in 30 newly diagnosed cases of periorbital hyperpigmentation and 14 controls from the post-auricular region. Melanocytes were labelled with the immunohistochemical stains, Melan-A and tyrosinase. We studied the linear keratinocyte density, mean linear melanocyte density, ratio of melanocytes to keratinocytes, the ratio between inner and outer epidermal length, maximum epidermal thickness and minimum epidermal thickness. RESULTS: Melan-A expression of melanocytes showed strong positive correlation (r=0.883) with the tyrosinase expression. Mean linear melanocyte density was 24/mm (range: 13-30/mm) in cases and 17/mm (13-21/mm) in controls and this difference was statistically significant (P<0.001). The mean ratio of melanocyte to keratinocyte was 0.22 (0.12-0.29) in cases and 0.16 (0.12-0.21) in controls; again, this difference was statistically significant (P<0.001). There was a mild negative correlation with linear keratinocyte density (r=-0.302) and the ratio between inner and outer epidermal length (r=-0.456). However, there were no differences in epidermal thicknesses. LIMITATIONS: There were fewer control biopsies than optimal, and they were not taken from the uninvolved periorbital region. CONCLUSION: Mean linear melanocyte density and the ratio of melanocytes to keratinocytes is increased in cases with periorbital hyperpigmentation. It is, therefore, likely that increased melanocyte density may be the key factor in the pathogenesis of periorbital hyperpigmentation.

The utility of dermoscopy in the diagnosis of evolving lesions of vitiligo.

BACKGROUND: Early lesions of vitiligo can be confused with various other causes of hypopigmentation and depigmentation. Few workers have utilized dermoscopy for the diagnosis of evolving lesions of vitiligo. AIM: To analyze the dermoscopic findings of evolving lesions in diagnosed cases of vitiligo and to correlate them histopathologically. METHODS: Dermoscopy of evolving lesions in 30 diagnosed cases of vitiligo was performed using both polarized light and ultraviolet light. RESULT: On polarized light examination, the pigmentary network was found to be reduced in 12 (40%) of 30 patients, absent in 9 (30%), and reversed in 6 (20%) patients; 2 patients (6.7%) showed perifollicular hyperpigmentation and 1 (3.3%) had perilesional hyperpigmentation. A diffuse white glow was demonstrable in 27 (90%) of 30 patients on ultraviolet light examination. Melanocytes were either reduced in number or absent in 12 (40%) of 30 patients on histopathology. CONCLUSION: Pigmentary network changes, and perifollicular and perilesional hyperpigmentation on polarized light examination, and a diffuse white glow on ultraviolet light examination were noted in evolving vitiligo lesions. Histopathological examination was comparatively less reliable. Dermoscopy appears to be better than routine histopathology in the diagnosis of evolving lesions of vitiligo and can obviate the need for a skin biopsy.

The armadillo as a model for peripheral neuropathy in leprosy.

Leprosy (also known as Hansen's Disease) is a chronic infectious disease caused by Mycobacterium leprae that primarily targets the peripheral nervous system; skin, muscle, and other tissues are also affected. Other than humans, nine-banded armadillos (Dasypus novemcinctus) are the only natural hosts of M. leprae, and they are the only laboratory animals that develop extensive neurological involvement with this bacterium. Infection in the armadillo closely recapitulates many of the structural, physiological, and functional aspects of leprosy seen in humans. Armadillos can be useful models of leprosy for basic scientific investigations into the pathogenesis of leprosy neuropathy and its associated myopathies, as well as for translational research studies in piloting new diagnostic methods or therapeutic interventions. Practical and ethical constraints often limit investigation into human neuropathies, but armadillos are an abundant source of leprotic neurologic fibers. Studies with these animals may provide new insights into the mechanisms involved in leprosy that also might benefit the understanding of other demyelinating neuropathies. Although there is only a limited supply of armadillo-specific reagents, the armadillo whole genomic sequence has been completed, and gene expression studies can be employed. Clinical procedures, such as electrophysiological nerve conduction testing, provide a functional assessment of armadillo nerves. A variety of standard histopathological and immunopathological procedures including Epidermal Nerve Fiber Density (ENFD) analysis, Schwann Cell Density, and analysis for other conserved cellular markers can be used effectively with armadillos and will be briefly reviewed in this text.

Increased tissue leptin hormone level and mast cell count in skin tags: a possible role of adipoimmune in the growth of benign skin growths.

BACKGROUND: Skin tags (ST) are common tumors. They mainly consist of loose fibrous tissue and occur on the neck and major flexures as small, soft, pedunculated protrusions. Decrease in endocrine, hormone level and other factors are thought to play a role in the evolution of ST. Leptin is an adipocyte-derived hormone that acts as a major regulatory hormone for food intake and energy homeostasis. Leptin deficiency or resistance can result in profound obesity and diabetes in humans. A role of mast cell in the pathogenesis of ST is well recognized. AIMS: To investigate the role of leptin in the pathogenesis of ST and to clarify whether there is a correlation between mast cell count and leptin level in ST. METHODS: Forty-five skin biopsies were taken from 15 patients with ST. From each patient, a biopsy of a large ST (length >4 mm), a small ST (length <2 mm) and a normal skin biopsy (as a control) were taken. The samples were processed for leptin level. Skin biopsies were stained with hematoxylin and eosin and toluidine blue-uranyl nitrate metachromatic method for mast cell count was used. RESULTS: There was a significant increased level of leptin in the ST compared to the normal skin. It was highly significant in small ST than in big ST (P = 0.0001) and it was highly significant in small and big ST compared to controls, P = 0.0001 and P = 0.001, respectively. There was a significant increase in mast cell count in the ST, which did not correlate with the increased levels of leptin. CONCLUSION: This is the first report to demonstrate that tissue leptin may play a role in the pathogenesis of ST. The significant increase in the levels of leptin and mast cell count in ST may indicate a possible role of adipoimmune in the benign skin growths.

Influence of cell geometry and number of replicas in the reproducibility of whole cell FTIR analysis.

Fourier Transform InfraRed (FTIR) spectroscopy is an increasingly used technique in biology, especially for whole cell metabolomic fingerprint. The reproducibility of this technique is influenced by a large number of factors such as the physiological state of cells, sample manipulation and growth conditions. Evidence exists suggesting that the cell shape and dimension can be further elements to consider in whole cell FTIR analysis. In this study we aimed to address the effect of cell geometry on the FTIR spectra and to define the extent of variability occurring between machine and biological replicas with a standardized protocol. The yeast species Saccharomyces cerevisiae (large oval-shaped cells) and Debaryomyces hansenii (small round shaped cells) were employed for their different morphology. Thirty machine replicas of each were analyzed separately and after averaging in groups of three, showing a three to four-fold reduction of the variability. Similarly, a two-fold reduction of variability was observed when thirty biological replicas of the two yeast species were analyzed. The optimal number of replicas to average was then estimated with a bootstrap-like procedure in which biological and machine replicas were randomly resampled 2000 times and averaged in groups spanning from 2 to 12 replicas. This simulation has shown that little if any advantage can be obtained by increasing the number of replicas over five and that the variability exhibited by the small regular cells of D. hansenii was always roughly half of that displayed by the large S. cerevisiae cells, confirming the results obtained with standard non-bootstrapped averages.

Long-term culture of multibacillary leprosy macrophages isolated from skin lesions: a new model to study Mycobacterium leprae-human cell interaction.

BACKGROUND: Leprosy is characterized by a disease spectrum having two polar clinical forms dependent on the presence or not of cell-mediated immunity. In the tuberculoid forms, granuloma-activated macrophages kill Mycobacterium leprae in conjunction with a Th1 response while, in multibacillary (MB) lesions, M. leprae nonactivated macrophages infiltrate the nerves and internal organs together with a Th2 response. The functional properties and activation pathways of macrophages isolated from patients with MB leprosy remain only partially understood. OBJECTIVES: To establish an ex vivo methodology capable of evaluating the activation pathways, grade and fate of cultured macrophages isolated from MB lesions. METHODS: Skin biopsies from patients with borderline tuberculoid, bordeline lepromatous and lepromatous leprosy (LL) were characterized by immunohistochemistry and transcriptional analysis. To isolate inflammatory cells, a portion of the samples was submitted to enzymatic digestion. These same cells, maintained in culture for a minimum 7-day period, were characterized morphologically and via flow cytometry at different culture time points. Cytokine [interferon (IFN)-gamma, tumour necrosis factor (TNF)-alpha and interleukin (IL)-10] mRNA levels were quantified by real-time polymerase chain reaction and protein secretion in the culture supernatants was measured by enzyme-linked immunosorbent assay and the nitric oxide levels by Griess reagent. RESULTS: RNA expression in tuberculoid and MB lesions showed the profile expected of characteristic Th1 and Th2 responses, respectively. The inflammatory cells in all biopsies were successfully isolated. Although the number of cells varied between biopsies, it was highest in LL biopsies. The frequency of isolated CD14+ and CD3+ cells measured by flow cytometry correlated with the percentages of macrophages and lymphocytes in the lesions. Throughout the culture period, CD68+ macrophages showed morphological changes. A progressive increase in cell number and reduction of infected cells were perceptible in the cultures. In contrast to the biopsies, TNF-alpha, IFN-gamma and IL-10 expression in the tuberculoid and MB leprosy cells in 24-h culture and the cytokine levels in the supernatants did not differ significantly. During the culture period, cytokine expression in the MB cells progressively declined, whereas, from days 1 to 7, nitrite levels progressively increased. After day 40, the remaining macrophages were able to ingest fluorescein isothiocyanate-labelled M. leprae. These data need to be confirmed. CONCLUSIONS: This study confirmed the feasibility of obtaining ex vivo macrophages from leprosy lesions and keeping them in long-term culture. This procedure may open new pathways to studying the interaction between M. leprae and human macrophages, which might, in turn, lead to the development of therapeutic tools capable of overcoming the specific anergy found in patients with MB leprosy.

Rifampicin attenuates the MPTP-induced neurotoxicity in mouse brain.

Rifampicin, an antibacterial drug, is highly effective in the treatment of tuberculosis and leprosy. Recently, it has been reported to have neuroprotective effects in in vitro and in vivo models. This study was designed to elucidate its neuroprotective effects against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced neurotoxicity (known as an in vivo mouse model of Parkinson's disease). Mice were injected intraperitoneally (i.p.) with MPTP (10 mg/kg) four times at 1-h intervals, and brains were analyzed 3 or 7 days later. Rifampicin at 20 mg/kg (i.p., twice) had protective effects against MPTP-induced neuronal damage (immunohistochemical changes in tyrosine hydroxylase) in both the substantia nigra and striatum. Rifampicin also protected against the MPTP-induced depletions of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in the striatum. The maximal concentrations of rifampicin between 30 and 240 min after a single rifampicin injection (20 mg/kg, i.p.) were 2.6 microM (at 30 min) in plasma and 0.77 microM (at 60 min) in striatum. Next, the effects of rifampicin on oxidative stress [lipid peroxidation in mouse brain homogenates and free radical-scavenging activity against diphenyl-p-picrylhydrazyl (DPPH)] were evaluated to clarify the underlying mechanism. At 1 microM or more, rifampicin significantly inhibited both lipid peroxidation in the striatum and free radical production. These findings suggest that in mice, rifampicin can reach brain tissues at concentrations sufficient to attenuate MPTP-induced neurodegeneration in the nigrostriatal dopaminergic neuronal pathway, and that an inhibitory effect against oxidative stress may be partly responsible for its observed neuroprotective effects.

Leprosy: contribution of mast cells to epineurial collagenization.

BACKGROUND: Leprosy, a disease caused by Mycobacterium leprae, is an important health problem worldwide. It is responsible for an irreversible nerve damage in which fibrosis plays an important role. The existence of an interaction between mast cells and different fibrotic conditions has long been observed. Tryptase, the most abundant protein product of human mast cells, has been shown to be mitogenic for fibroblasts and to increase type I collagen production. PATIENTS AND METHODS: In order to explore the possible relationship between tryptase-rich mast cells and nerve fibrosis in leprosy, we studied 24 sural nerve biopsies of patients with leprous neuropathy. Mast cells stained with mouse antihuman mast cell antitryptase clone AA1 as well as fibrosis, were quantitatively estimated in both epi- and endoneurial compartments. RESULTS: There was a remarkable association between collagen increase and tryptase-rich mast cell density in the epineurium but not in the endoneurium of leprous nerves. CONCLUSION: Since the epineurium in leprosy is type I collagen rich, the present findings support a tryptase-rich mast cell contribution to epineurial collagenization in leprosy through their tryptase secretion.

Manifestações de padrão tuberculóide reacional na hanseníase dimorfa: estudo histoquímico e imuno-histoquímico comparativo, em biópsias cutâneas, entre reações tipo 1 ocorridas antes e durante a poliquimioterapia / Manifestations of reactional tuberculoid pattern in borderline leprosy: comparative, histochemical and immunohistochemical study, in skin biopsies, between type 1 reactions ocurred before and during multidrugtherapy

FUNDAMENTOS: Na hanseníase dimorfa é comum a ocorrência de reações tipo 1 antes, durante ou depois da poliquimioterapia (PQT). Trabalhos recentes sugerem que a reação tipo 1 seria um desequilíbrio imunológico entre citocinas pró-inflamatórias e antiinflamatórias. OBJETIVOS: Compreender melhor a fisiopatologia das reações tipo 1. MÉTODOS: Estudaram-se biópsias cutâneas de 10 indivíduos com hanseníase dimorfa-tuberculóide reacional não tratada (DTR) e 10 dimorfos em reação reversa após o início da PQT (DRR), comparando-se os parâmetros morfológicos e imunológicos por meio de colorações HE e Faraco-Fite, e técnicas imuno-histoquímicas (CD4, CD8, CD20, CD79a, CD57, iNOS, IL-10, LAM e BCG). RESULTADOS: Houve, nos DRR, mais macrófagos multivacuolados, maior marcação nos macrófagos para a enzima óxido nítrico sintase induzível (iNOS) e menos linfócitos T CD8+ (p<0,05). Afora a presença de bacilos típicos nos DTR e sua ausência nos DRR, não houve diferenças na baciloscopia ou na marcação para antígenos micobacterianos (LAM e BCG) entre os grupos. O número de células IL-10+ foi similar nos dois grupos, porém houve correlação negativa entre essa citocina e a proporção CD4/CD8 apenas nos pacientes DRR (p<0,05). Houve tendência à redução do infiltrado específico e ao maior número de células NK nos DRR. CONCLUSÃO: Na presença de muitos bacilos viáveis em um paciente sem imunidade celular plena, haveria tendência à piora imunológica (downgrading). A PQT, ao reduzir a carga bacilar, melhoraria a imunidade celular (upgrading), com posterior desvio da imunidade adquirida para a inespecífica (resposta Th3), evoluindo para a cura.

BACKGROUND: Type 1 reactions are common in borderline leprosy, and can occur before, during or after multidrugtherapy (MDT). Recent papers suggest that these reactions could be a result of an imbalance between proinflammatory and anti-inflammatory citokines. OBJECTIVE: To understand better the physiopathology of type 1 reactions. METHODS: We studied skin biopsies from 10 non-treated patients with reactional borderline tuberculoid leprosy (BTR) and 10 from borderline leprosy with reversal reactions after the beginning of MDT (BRR), to compare morphological and immunological parameters by routine staining (H-E and Faraco-Fite) and immunohistochemical technics (CD4, CD8, CD20, CD79a, CD57, iNOS, IL-10, LAM and BCG). RESULTS: We found, in BRR group, stronger staining for iNOS into macrofages, fewer CD8+ T cells and more multivacuolated macrofages than BTR group (p<0,05). Despite the presence of viable bacilli in BTR and its absence in BRR, there weren't differences in baciloscopy and staining for mycobacterial antigens (LAM and BCG) between the groups. The number of IL-10+ cells was similar in both groups, but there was a negative correlation between this cytokine and the CD4:CD8 ratio only in BRR group (p<0,05). It was seen a tendency for a decreased specific infiltrate and increased number of NK cells in BRR group. CONCLUSIONS: The presence of many viable bacilli in a patient with partial cellular immunity could worse the immunological status (downgrading). Once started MDT, the reduction bacilli charge would improve cellular immunity (upgrading), with latter shift to innate immunity (Th3 response), evolving to cure.

Hanseníase dimorfa reacional: estudo comparativo, em biópsias cutâneas, entre reações tipo 1 ocorridas antes e durante a poliquimioterapia / Manifestations of reactional tuberculoid patterns in borderline leprosy: comparative study, in cutaneous biópsias, between occured reactions type 1 before and during the multidrugtherapy

A hanseníase dimorfa é a forma clínica mais freqüentemente associada à ocorrência de reações de hipersensibilidade mediada por células (reações tipo 1), que podem ocorrer antes, durante ou depois do tratamento específico. Há várias teorias a respeito da patogênese dessas reações, as quais estão diretamente ligadas ao dano neural e às seqüelas. Visando-se compreender melhor a fisiopatologia das reações tipo 1, foram estudadas 10 biópsias cutâneas de indivíduos com hanseníase dimorfatuberculóidereacional não tratados e 10 de indivíduos dimorfos em reação reversa (após o início do tratamento específico), comparando-se os parâmetros morfológicos e imunoistoquímicos. Observou-se, no grupo em tratamento, maior positividade das células para a enzima óxido nítricosintase induzível (iNOS) e menor quantidade de linfócitos T CD8+ (p<0,05).Não houve diferenças significativas na baciloscopia e positividade para antígenos micobacterianos nos dois grupos, e nem na quantidade de células IL-10+, apesar de ter sido observada correlação negativa entre esta citocinae a proporção CD4/CD8 nos pacientes em tratamento (p<0,05). Notou-se, também, tendência à redução do infiltrado específico (linfócitos T e B) e aumento do número de células citotóxicas inespecíficas (NK) no grupo em tratamento. Estes resultados são concordantes com trabalhos recentes, que sugerem que a reação tipo 1 representaria um desequilíbrio imunológico entre citocinas pró-inflamatórias e anti-inflamatórias. Na presença de muitos bacilos viáveis e no contexto de um paciente sem imunidade celular plena, haveria uma tendência à piora no sentido do pólo virchoviano (downgrading), porém o tratamento específico, reduzindo a carga bacilar, favoreceria uma melhora da imunidade efetiva, caracterizada por um quadro histológico mais tuberculóide, com posterior desvio progressivo da imunidade adquirida para a inespecífica (resposta Th3 ou reguladora), interrompendo a reação e levando à cura

Hanseníase dimorfa reacional: estudo comparativo, em biópsias cutâneas, entre reações tipo 1 ocorridas antes e durante a poliquimioterapia

A hanseníase dimorfa é a forma clínica mais freqüentemente associada à ocorrência de reações de hipersensibilidade mediada por células (reações tipo 1), que podem ocorrer antes, durante ou depois do tratamento específico. Há várias teorias a respeito da patogênese dessas reações, as quais estão diretamente ligadas ao dano neural e às seqüelas. Visando-se compreender melhor a fisiopatologia das reações tipo 1, foram estudadas 10 biópsias cutâneas de indivíduos com hanseníase dimorfatuberculóidereacional não tratados e 10 de indivíduos dimorfos em reação reversa (após o início do tratamento específico), comparando-se os parâmetros morfológicos e imunoistoquímicos. Observou-se, no grupo em tratamento, maior positividade das células para a enzima óxido nítricosintase induzível (iNOS) e menor quantidade de linfócitos T CD8+ (p<0,05).Não houve diferenças significativas na baciloscopia e positividade para antígenos micobacterianos nos dois grupos, e nem na quantidade de células IL-10+, apesar de ter sido observada correlação negativa entre esta citocinae a proporção CD4/CD8 nos pacientes em tratamento (p<0,05). Notou-se, também, tendência à redução do infiltrado específico (linfócitos T e B) e aumento do número de células citotóxicas inespecíficas (NK) no grupo em tratamento. Estes resultados são concordantes com trabalhos recentes, que sugerem que a reação tipo 1 representaria um desequilíbrio imunológico entre citocinas pró-inflamatórias e anti-inflamatórias. Na presença de muitos bacilos viáveis e no contexto de um paciente sem imunidade celular plena, haveria uma tendência à piora no sentido do pólo virchoviano (downgrading), porém o tratamento específico, reduzindo a carga bacilar, favoreceria uma melhora da imunidade efetiva, caracterizada por um quadro histológico mais tuberculóide, com posterior desvio progressivo da imunidade adquirida para a inespecífica (resposta Th3 ou reguladora), interrompendo a reação e levando à cura

Hanseniase dimorfa reacional: estudo comparativo, em biopsias cutaneas, entre reacao tipo 1 ocorridas antes e durante a poliquimioterapia / ?

A hanseniase dimorfa e a forma clinica mais frequentemente associada a ocorrencia de reaçoes de hipersensibilidade medida por celulas (reacao tipo 1), que podem ocorrer antes, durante ou depois do tratamento especifico. Ha varias teorias a respeito da patogenese dessas reacoes, as quais estao diretamente ligadas ao dano neural e as sequelas. Visando-se compreender melhor a fisiopatologia das reacoes tipo 1, foram estudadas 10 biopsias cutaneas de individuos com hanseniase dimorfa-tuberculoide reacional nao tratados e 10 de individuos dimorfos em reacao reversa (apos o inicio do tratamento especifico), comparando-se os parametros morfologicos e imunoistoquimicos. Observou-se no grupo em tratamento, maior positividade das celulas para a enzima oxida nitrico sintase induzivel (iNOS) e menor quantidade de linfocitos T CD8+(p menor 0,05). Nao houve diferenças significativas na baciloscopia e positividade para antigenos micobacterianos nos dois grupos, e nem na quantidade de celulas IL-10+, apesar de ter sido observada correlaçao negativa entre esta citocina e a proporçao CD4/CD8 nos pacientes em tratamento (p menor 0,05). Notou-se tambem, tendencia a reduçao do infiltrado especifico (linfocitos T e B) e aumento do numero de celulas citotoxicas inespecificas (NK) no grupo em tratamento. Estes resultados sao concordantes com trabalhos recentes, que surgerem que a reaçao tipo 1 representaria um desiquilibrio imunologico entre citocinas pro-inflamatorias e anti-inflamatorias...

A study of mast cells in granulomatous lesions of skin, with special emphasis on leprosy.

76 skin biopsies that included material from 7 controls, 65 granulomatous skin lesions and 2 each of granulation tissue and chronic non-specific inflammation, were subjected to histopathological evaluation on haematoxylin and eosin and pertinent special stains. Mast cell study was done on slides stained by toluidine blue method, with special reference to their location, and morphology and cell count were done with the help of occculomicrometre. In normal skin, mast cell density was 11.43/mm2 with a range of 6-22/mm2 and an S.D. of 5.94. Highest value in the whole series was seen in TVC (66/mm2), followed by lupus vulgaris (50/mm2). Mast cell counts were normal in indeterminate and TT leprosy and showed a rise over the immunological spectrum BT to LL, with values in LL being 32.86/mm2 (28-40/mm2).

Rifampicin inhibits neurodegeneration in the optic nerve transection model in vivo and after 1-methyl-4-phenylpyridinium intoxication in vitro.

Rifampicin is an antibacterial drug which is highly effective in the treatment of tuberculosis and leprosy. It has been shown to exert antioxidative as well as anti-apoptotic effects. In this study, the neuroprotective effect of rifampicin was examined after 1-methyl-4-phenylpyridinium (MPP+)-induced dopaminergic cell death in vitro, and on the survival of retinal ganglion cells after optic nerve transection in vivo. Rifampicin administration significantly increased the number of surviving dopaminergic neurons after MPP+ intoxication as compared to control cultures. No cytotoxic effects were noted even at final rifampicin concentrations of 100 microM. In the rifampicin-treated group, retinal ganglion cell survival was significantly increased after axotomy as compared with vehicle-treated and phosphate-buffered saline-treated control animals. These results suggest that rifampicin is able to prevent neuronal degeneration in cell death paradigms involving oxidative stress and activation of apoptotic pathways. It may thus play a role in the future treatments of neurodegenerative disorders.

Rifampicin attenuates brain damage in focal ischemia.

Rifampicin is an antibacterial agent that is widely used in tuberculosis and leprosy therapy. Interestingly, some experimental studies indicate that rifampicin acts as a hydroxyl radical scavenger and a glucocorticoid receptor activator. In this study, the neuroprotective effect of rifampicin was evaluated after transient and permanent focal cerebral ischemia. Anaesthetized male C57BL/6j mice were submitted to permanent or transient thread occlusion of the middle cerebral artery (MCA). Reperfusion in transient ischemia was initiated 30 min later by thread retraction. Rifampicin or vehicle were applied intraperitoneally before permanent or immediately after 30 min of transient ischemia. Later, 24 h after permanent or transient ischemia, animals were re-anesthetized and decapitated. Brain injury was evaluated by triphenyltetrazolium chloride staining (TTC), terminal transferase biotinylated-dUTP nick end labeling (TUNEL) and cresyl violet staining. A 20-mg/kg sample of rifampicin showed a significant neuroprotection after cerebral ischemia. The number of TUNEL-positive cells in the striatum, where disseminated tissue injury was observed, was also reduced by application of rifampicin as compared with vehicle-treated animals. The present report shows that administration of rifampicin efficiently reduces brain injury after permanent and transient focal cerebral ischemia in mice.

Mast cell subsets and neuropeptides in leprosy reactions.

The immunohistochemical identification of neuropeptides (calcitonin gene-related peptide, vasoactive intestinal polypeptide, substance P, alpha-melanocyte stimulating hormone and gamma-melanocyte stimulating hormone) quantification of mast cells and their subsets (tryptase/chymase-immunoreactive mast cells = TCMC and tryptase-immunoreactive mast cells = TMC) were determined in biopsies of six patients with leprosy reactions (three patients with type I reaction and three with type II). Biopsies were compared with those taken from the same body site in the remission stage of the same patient. We found a relative increase of TMC in the inflammatory infiltrate of the reactional biopsies compared to the post-reactional biopsy. Also, the total number of mast cells and the TMC/TCMC ratio in the inflammatory infiltrate was significantly higher than in the intervening dermis of the biopsies of both periods. No significant difference was found regarding neuroptide expression in the reactional and post-reactional biopsies. The relative increase of TMC in the reactional infiltrates could implicate this mast cell subset in the reported increase of the immune response in leprosy reactions.

Mast cell subsets and neuropeptides in leprosy reactions

The immunohistochemical identification of neuropeptides (calcitonin gene-related peptide, vasoactive intestinal polypeptide, substance P, alpha-melanocyte stimulating hormone and gamma-melanocyte stimulating hormone) quantification of mast cells and their subsets (tryptase/chymase-immunoreactive mast cells = TCMC and tryptase-immunoreactive mast cells = TMC) were determined in biopsies of six patients with leprosy reactions (three patients with type I reaction and three with type II). Biopsies were compared with those taken from the same body site in the remission stage of the same patient. We found a relative increase of TMC in the inflammatory infiltrate of the reactional biopsies compared to the post-reactional biopsy. Also, the total number of mast cells and the TMC/TCMC ratio in the inflammatory infiltrate was significantly higher than in the intervening dermis of the biopsies of both periods. No significant difference was found regarding neuroptide expression in the reactional and post-reactional biopsies. The relative increase of TMC in the reactional infiltrates could implicate this mast cell subset in the reported increase of the immune response in leprosy reactions

Study of mast cells in non-neoplastic skin lesions.

Sixty non-neoplastic skin lesions were studied for mast cells by toluidine blue stain. The highest numbers of mast cells were seen in the viral infections of the skin (50/mm2) and lowest number of mast cells in congenital diseases (17/mm2). Out of the cutaneous bacterial infections, highest numbers of mast cells were seen in leprosy (44/mm2) while in lupus vulgaris they were much less (37/mm2). In leprosy cases it was observed that as the lesions moved from indeterminate to both polar tuberculoid and lepromatous, the mast cell count increased. It could therefore be summarised that periodic follow-up of indeterminate and borderline lesions for mast cell count might help in predicting stability of lesions. In non-infectious squamous and papular lesions the mean mast cell count was 39/mm2. The highest numbers of mast cells in the non-infectious vesicular and bullous lesions were in bullous pemhigoid (57/mm2) and lowest in dermatitis (38/mm2).