Brain glycogen supercompensation after different conditions of induced hypoglycemia and sustained swimming in rainbow trout (Oncorhynchus mykiss).

Brain glycogen is depleted when used as an emergency energy substrate. In mammals, brain glycogen levels rebound to higher than normal levels after a hypoglycemic episode and a few hours after refeeding or administration of glucose. This phenomenon is called glycogen supercompensation. However, this mechanism has not been investigated in lower vertebrates. The aim of this study was therefore to determine whether brain glycogen supercompensation occurs in the rainbow trout brain. For this purpose, short-term brain glucose and glycogen contents were determined in rainbow trout after being subjected to the following experimental conditions: i) a 5-day or 10-day fasting period and refeeding; ii) a single injection of insulin (4 mg kg(-1)) and refeeding; and iii) sustained swimming and injection of glucose (500 mg kg(-1)). Food deprivation during the fasting periods and insulin administration both induced a decrease in glucose and glycogen levels in the brain. However, only refeeding after 10 days of fasting significantly increased the brain glycogen content above control levels, in a clear short-term supercompensation response. Unlike in mammals, prolonged exercise did not alter brain glucose or glycogen levels. Furthermore, brain glycogen supercompensation was not observed after glucose administration in fish undergoing sustained swimming. To our knowledge, this is the first study providing direct experimental evidence for the existence of a short-term glycogen supercompensation response in a teleost brain, although the response was only detectable after prolonged fasting.

Effects of acute handling stress on cerebral monoaminergic neurotransmitters in juvenile Senegalese sole Solea senegalensis.

Juvenile Senegalese sole Solea senegalensis were subjected for short periods to two different types of handling-related stress: air exposure stress and net handling stress. The S. senegalensis were sacrificed 2 and 24 h after the stress events and the levels of serotonin (5-HT), noradrenaline (NA), dopamine (DA) and their respective major metabolites, 5-hydroxyindoleacetic acid (5-HIAA), 3-methoxy-4-hydroxyphenylglycol (MHPG) and 3,4-dihydroxyphenylacetic acid (DOPAC), were measured in three brain regions (telencephalon, hypothalamus and optic tectum) and compared with those in control, non-stressed S. senegalensis. Neither type of stress caused any significant alteration of serotoninergic activity (5-HIAA:5-HT ratio) or NA levels. Dopaminergic activity (DOPAC:DA ratio) was lower in stressed fish in all of the brain regions studied. For both air exposure stress and net handling stress, DA levels were significantly higher (P < 0.05) than in the control S. senegalensis. In addition, the higher DA levels after net handling stress were always significantly higher (P < 0.05) than those observed after acute air exposure stress, except in the telencephalon after 24 h. The significantly lower DOPAC:DA ratio (P < 0.05) in all of the brain regions studied was only observed in response to net handling stress.

Effects of acute exposure to exogenous ammonia on cerebral monoaminergic neurotransmitters in juvenile Solea senegalensis.

The present study explored the potential role of brain catecholaminergic and serotoninergic systems as neuronal targets for the toxicological effects of acute ammonia exposure (0.28 mg l(-1) of un-ionized ammonia for 12 and 24 h) in juvenile sole (Solea senegalensis). In addition, plasma cortisol levels were measured. The results showed significant increases in their concentrations that were similar after 12 and 24 h of exposure. These data indicate that acute exposure (12 and 24 h) to ammonia initiates a typical stress response in the Senegalese sole, with stimulation of the hypothalamus-pituitary-interrenal axis. The concentrations of dopamine (DA), serotonin (5-hydroxytryptamine; 5-HT) and noradrenaline (NA), and their metabolites, 3, 4-dihydroxyphenylacetic acid (DOPAC) and 5-hydroxy-3-indoleacetic acid (5HIAA), were measured in the hypothalamus, telencephalon and optic tectum. The main changes induced by acute exposure to ammonia were decreases in the concentrations of 5-HT and DA, which were significant in most of the brain regions studied. The ratios of 5-HIAA/5-HT and DOPAC/DA increased in all regions and at all times studied, although in the case of the DOPAC/DA ratio, the increases were only significant in the hypothalamus (24 h exposure) and in the optic tectum (12 and 24 h exposure). These changes indicated that exposure to ammonia elicited time-dependent increases in serotoninergic and dopaminergic activity in the hypothalamus, telencephalon and optic tectum.

Immunohistochemical expression of matrix metalloproteinases in photodamaged skin by photodynamic therapy.

BACKGROUND: Photodynamic therapy (PDT) has been described for photoageing treatment, but its mechanism of action is not clarified. Although PDT-induced matrix metalloproteinase (MMP) expression and collagen production have been studied in normal skin and in inflammatory disease, there is no report about the effect of PDT on the extracellular matrix in photodamaged skin. OBJECTIVES: To evaluate skin remodelling induced by methyl aminolaevulinate (MAL)-PDT in photodamaged skin by histological and immunohistochemical studies. METHODS: Fourteen patients were treated with two sessions of MAL-PDT. The light source was a light-emitting diode (635 nm, 37 J cm(-2)). Skin biopsies were performed in all patients before and at 3 and 6 months after treatment. Immunohistochemical studies evaluated collagen types I and III, MMP-1, MMP-3, MMP-7, MMP-9, MMP-12 and tissue inhibitor of metalloproteinases-1. RESULTS: Global improvement in photodamaged skin was observed. A significant increase in expression of MMP-9 in the dermis was detected at 3 months after treatment (P = 0.002). Significant increases in the expression of collagen type I at 3 months (P = 0.002) and at 6 months after treatment (P = 0.001) were also observed. CONCLUSIONS: Skin remodelling induced by MAL-PDT was demonstrated in photodamaged skin. Two sessions of MAL-PDT increases immunohistochemical expression of MMP-9 in the dermis at 3 months after treatment, and also of collagen type I.

Appearance of T-cell subpopulations during the time course of beryllium-induced granulomas.

Employing monoclonal antibodies that identify T-helper/inducer or T-suppressor/cytotoxic cells, we investigated the T-lymphocyte subsets in hypersensitivity granulomas developed after beryllium salt injection. T-helper/inducer cells were detected at all stages of the lesions, including early nonspecific inflammatory lesions seen at 3 weeks after injection. They formed clusters intermingled with the mononuclear phagocytes in granulomatous lesions, but were not found among the epithelioid cells. In contrast, T-suppressor/cytotoxic cells were slow to appear in the lesions and constituted very small numbers in mature epithelioid cell granulomas of 9-11 weeks. These findings suggest that T-helper/inducer cells may be responsible for the evolution of the perivascular infiltrate of mononuclear cells. Furthermore, appearance of T-helper/inducer cells without T-suppressor/cytotoxic cells may contribute to the development and organization of epithelioid cells and their maturity in the granulomatous lesions.

Effect of ultraviolet B radiation on S-100 protein antigen in epidermal Langerhans cells.

Ultraviolet B (UVB) radiation has been shown to induce significant alterations in both function and surface antigen expression of epidermal Langerhans cells (ELC). In this study we investigated the effect of UVB radiation on ELC marker S-100 protein antigen (S-100 Ag) which is present in the nucleus and cytoplasm of human ELC. A total of 34 sites on 31 volunteers were exposed to 3 MED (minimal erythema dose) of UVB and biopsied at various times up to 7 days after irradiation. Skin from 9 noninjured and 7 slice-wounded subjects served as controls. The avidin-biotin-peroxidase staining technique was used to identify S-100 Ag in sections of formalin-fixed, paraffin-embedded tissue, and the numbers of stained suprabasal dendritic cells were then counted over a 200 basal cell length of interfollicular epidermis. Noninjured skin had 3.56 +/- 3.01 cells, whereas slice-wounded skin had elevated numbers (greater than 10.0 cells) at 1, 24, and 48 h after injury. Following UVB irradiation, a significant (p less than 0.001) increase in antigen-positive cells (14 +/- 3.46) was found at 1 h; this number declined to just below normal at 12 h, but by 48 h returned to and remained at preinjury levels. In contrast to previous observations of the depletion of ELC surface markers by UVB radiation, we demonstrate here that the numbers of S-100 Ag-positive ELC actually increase following comparable doses of radiation. Since this increase occurs so rapidly following both UVB irradiation and slice injury, S-100 Ag may be synthesized or unmasked within the ELC as a response to wounding of the epidermis.

Immunohistochemical demonstration of S-100 protein antigen-containing cells in beryllium-induced, zirconium-induced and sarcoidosis granulomas.

S-100 protein has been detected in epidermal Langerhans cells, interdigitating reticulum cells, and large mononuclear cells of cutaneous T-cell lymphomas. Experimental data imply these cells are involved in the presentation of antigens and/or maturation of T-lymphocytes. The authors studied the morphology and distribution of S-100 protein antigen-containing cells in cutaneous sarcoidosis and metal-induced granulomas, both immunogenic and foreign-body types, with light and electron microscopic immunoperoxidase technics. Immunological reaction was seen in Langerhans cells, peripheral nerves, and granulomatous lesion dendritic cells. The latter showed a large, irregular nucleus and branching cytoplasm. They intermingled with other mononuclear cells in the granulomas but not with organized epithelioid cells. Morphometric quantification of dendritic cells in the three types of granulomas revealed statistically significant differences (P less than 0.005) and electron microscopy demonstrated their typical cytoplasmic appearance, without Birbeck granules. The increased number of dendritic cells in immunogenic granulomas, and their shared antigenic components with Langerhans cells suggest they act as accessory cells in eliciting the granulomatous response.

Antibiotic regimen as an independent risk factor for disseminated fungal infections in neutropenic patients in Brazil.

In a cohort of 79 febrile episodes in 50 consecutive neutropenic patients seen at the University Hospital, Federal University of Rio de Janeiro, Brazil, between 1987 and 1991, it was observed that the cumulative incidence of disseminated fungal infections rose from 3% to 19% after the introduction of a new empirical antibiotic regimen. In order to identify risk factors, as well as to assess the impact of the new antibiotic regimen on the emergence of fungal infections, a nested case-control study was undertaken, in which 10 cases of disseminated fungal infections were compared with 30 randomly chosen controls, drawn from the same cohort. In a multiple logistic regression analysis, the predictive factors for disseminated fungal infection were younger age (odds ratio 0.85, 95% confidence interval 0.75-0.97) and use of the new antibiotic regimen (odds ratio 14.18, 95% confidence interval 1.05-191.80) The probable explanation for the emergence of fungal infections is that the new antibiotic regimen, by lowering the incidence of bacteraemia-related deaths, allowed patients to be at risk for the development of disseminated fungal infections.

Erythema nodosum: prospective study of 32 cases.

The results of 32 cases studied lead us to the conclusion that erythema nodosum's investigation routine is very important, once in our retrospective study, the percentage of cases of unknown etiology was 69.4%, and in this prospective study it is 21.8%. In 10 cases (31.2%), more than one causing agent was suspected. Infections (bacterial, helminthic, fungal, by protozoa) were diagnosed in 26 cases, streptococcal infection having predominated (12 cases). Drugs-dipirone, aspirin, anovulatory--were suspected as causing agents in 13 cases. The association of erythema nodosum and histoplasmosis capsulata is described for the first time in Brazil. We consider erythema nodosum to be a complex syndrome which should be regarded as a manifestation of underlying diseases. The fact that all 32 subjects were women, 26 of them during menacme, suggests that particular hormonal media may favor the action of various processes (infections and drugs), precipitating erythema nodosum's clinical picture.

Bacillary angiomatosis: description of 13 cases reported in five reference centers for AIDS treatment in Rio de Janeiro, Brazil.

The aim of this case series was to describe the clinical, laboratory and epidemiological characteristics and the presentation of bacillary angiomatosis cases (and/or parenchymal bacillary peliosis) that were identified in five public hospitals of Rio de Janeiro state between 1990 and 1997; these cases were compared with those previously described in the medical literature. Thirteen case-patients were enrolled in the study; the median age was 39 years and all patients were male. All patients were human immunodeficiency virus type 1 (HIV-1) infected and they had previous or concomitant HIV-associated opportunistic infections or malignancies diagnosed at the time bacillary angiomatosis was diagnosed. Median T4 helper lymphocyte counts of patients was 96 cells per mm(3). Cutaneous involvement was the most common clinical manifestation of bacillary angiomatosis in this study. Clinical remission following appropriate treatment was more common in our case series than that reported in the medical literature, while the incidence of relapse was similar. The frequency of bacillary angiomatosis in HIV patients calculated from two of the hospitals included in our study was 1.42 cases per 1000 patients, similar to the frequencies reported in the medical literature. Bacillary angiomatosis is an unusual opportunistic pathogen in our setting.

Adult T-cell leukemia/lymphoma associated with HTLV-1 infection in a Brazilian adolescent.

We present the case of a 15-year-old patient infected with HTLV-1 who developed a cutaneous T-cell lymphoma, confirmed by histopathological and immunohistochemical examination, as well as clinically and hematologically confirmed leukemia. The patient died 3 months after initial presentation of the disease. The rarity of the disease in this age group justifies the present report.

Melanoma and pregnancy with placental metastases. Report of a case.

The authors report on the case of a 33-year-old white woman who developed melanoma during pregnancy, with widespread metastatic disease involving the placenta. The melanoma developed during two consecutive pregnancies and was untreated throughout the course of both. The patient died with widespread metastases shortly after attempted Cesarean delivery of her second child. Histopathologic and immunohistochemical studies were made with anti-S-100 protein and HMB45 antibodies. The authors discuss the possible influence of pregnancy on the prognosis of melanoma.

Cutaneous involvement of systemic fungal infections in neutropenic patients.

Skin nodules can be the first evidence of a disseminated fungal infection in febrile neutropenic patients. We present our experience in the diagnosis of this clinical problem in five patients treated for serious hematologic conditions in our Service. There were two cases of Candida sp., two of Fusarium sp., and one of Trichosporon sp.. The immediate assessment of any suspicious lesion, including a biopsy of the lesion for microbiological and histopathologic examinations, will usually lead to the correct diagnosis.

HMB45 negative spindle cell malignant melanoma.

Desmoplastic malignant melanoma (DMM) and spindle cell malignant melanoma (SCMM) form a continuum without a discrete separation. One feature characteristic of DMM is a negative reaction for HMB45, a marker for premelanosomes. Fifty-six cases of SCMM were stained with HMB45. The clinical features, histologic features, and survival data for HMB45(+) and HMB45(-) SCMM were compared. Thirty cases were HMB45(-), and 26 were HMB45(+). In the HMB45(-) cases, there was a 1.4:1 ratio of males to females, and in the HMB45(+) cases the ratio was 1:1.5. Only 12.9% of the HMB45(-) cases occurred on the trunk compared with 40% of the HMB45(+) cases. The average ages for the HMB45(-) and the HMB45(+) cases were 65.6 and 61 years, respectively. Follow-up was obtained on 22 cases: 11 HMB45(-) and 11 HMB45(+). Of the 11 HMB45(-) cases, four had a 5-year disease-free survival. Of the 11 HMB45(+) cases, only one had a 5-year disease free survival. HMB45(-) SCMM appear to have a less aggressive biologic potential than HMB45(+) SCMM.

Arrector pili muscle: evidence of proximal attachment variant in terminal follicles of the scalp.

BACKGROUND: There is general agreement that the proximal attachment site of the arrector pili (AP) muscle, via elastic tendons, is the bulge region, where follicular stem cells are situated. A variant of this insertion, in which the AP muscle surrounds the follicle circumference, has been described in human facial vellus hair follicles. OBJECTIVES: To investigate whether terminal hair follicles of the human scalp may also present this variant of proximal insertion of the AP muscle. METHODS: Histological and immunohistochemical methods were used. RESULTS: At the bulge level, bundles of the AP muscle were seen to encircle the entire hair follicle. CONCLUSIONS: Terminal follicles of the human scalp may also present this variant of proximal insertion of the AP muscle.

Distinct histopathological patterns in single lesion leprosy patients treated with single dose therapy (ROM) in the Brazilian Multicentric Study.

This paper aims to describe the histomorphologic features of skin biopsies of single lesion leprosy patients recruited at outpatient clinics in four Brazilian states in the Northeast (Amazonas and Rondonia), Southeast (Rio de Janeiro) and Center-West (Goiás) between October 1997 and December 1998. Patients clinically diagnosed as single skin lesion paucibacillary (SSL-PB) leprosy had a standard 4-mm punch biopsy taken from the lesion before rifampin, ofloxacin, minocycline (ROM) therapy. The features of the cellular inflammatory infiltrates, the presence of nerve involvement and acid-fast bacilli (AFB) were used to categorize SSL-PB biopsies into different histopathological groups. Two-hundred-seventy-eight (93.0%) out of 299 patients had a skin biopsy available. Seven single lesion patients were diagnosed as BL or LL leprosy types (MB) by the histopathological exams and 12 cases were excluded due to other skin diseases. Therefore, 259 patients had skin lesions with histomorphological features compatible with PB leprosy categorized as follows: 33.6% (N = 87) of the biopsies represented well-circumscribed epithelioid cell granuloma (Group 1); 21.6% (N = 56) less-circumscribed epithelioid cell granuloma (Group 2); 12.0% (N = 31) were described as mononuclear inflammatory infiltrate permeated with epithelioid cells (Group 3), and 29.7% (N = 77) had perivascular/periadnexal mononuclear inflammatory infiltrate (Group 4). Minimal/no morphological alteration in the skin was detected in only 8 (3.1%) SSL-PB patients categorized as Group 5, who were considered to have leprosy by clinical parameters. SSL-PB leprosy patients recruited in a multicentric study presented histomorphology readings comprising the whole PB leprosy spectrum but also a few MB cases. These results indicate heterogeneity among SSL-PB patients, with a predominance of well-circumscribed and less-circumscribed epithelioid cell granulomas (Groups 1 and 2) in the sites studied and the heterogeneity of local cellular immune response.