Replacement of Candida albicans with C. dubliniensis in human immunodeficiency virus-infected patients with oropharyngeal candidiasis treated with fluconazole

Candida dubliniensis is an opportunistic yeast that has been increasingly implicated in oropharyngeal candidiasis (OPC) in human immunodeficiency virus (HIV)-infected patients but may be underreported due to its similarity with Candida albicans. Although most C. dubliniensis isolates are susceptible to fluconazole, the inducibility of azole resistance in vitro has been reported. Thus, the use of fluconazole prophylaxis in the treatment of these patients may have contributed to the increasing rates of isolation of C. dubliniensis. In this study, yeast strains were collected from the oral cavities of HIV-infected patients enrolled in a longitudinal study of OPC. Patients received fluconazole for the suppression or treatment of OPC, and isolates collected at both study entry and end of study were chosen for analysis. Samples were plated on CHROMagar Candida medium for initial isolation and further identified by Southern blot analysis with the species-specific probes Ca3 (for C. albicans) and Cd25 (for C. dubliniensis). Fluconazole MICs were determined by using NCCLS methods. At study entry, susceptible C. albicans isolates were recovered from oral samples in 42 patients who were followed longitudinally (1 to 36 months). C. albicans strains from 12 of these patients developed fluconazole resistance (fluconazole MIC, >/=64 micro g/ml). C. dubliniensis was not detected at end of study in any of these patients. Of the remaining 30 patients, eight (27%) demonstrated a replacement of C. albicans by C. dubliniensis when a comparison of isolates obtained at baseline and those from the last culture was done. For the 22 of these 30 patients in whom no switch in species was detected, the fluconazole MICs for initial and end-of-study C. albicans isolates ranged from 0.125 to 2.0 micro g/ml. For the eight patients in whom a switch to C. dubliniensis was detected, the fluconazole MICs for C. dubliniensis isolates at end of study ranged from 0.25 to 64 micro g/ml: the fluconazole MICs for isolates from six patients were 0.25 to 2.0 micro g/ml and those for the other two were 32 and 64 micro g/ml, respectively. In conclusion, a considerable number of patients initially infected with C. albicans strains that failed to develop fluconazole resistance demonstrated a switch to C. dubliniensis. C. dubliniensis in this setting may be underestimated due to lack of identification and may occur due to the impact of fluconazole on the ecology of oral yeast species.     

Dominantly inherited tubular aggregate myopathy.

We report an unusual familial myopathy characterized morphologically by the presence of large tubular aggregates in all fibre types. Two patients, a father and daughter, presented with slowly progressive proximal weakness, limitation of eye movement, and Achilles tendon contractures. Serum creatine kinase was 5-10 times normal. Light microscopy revealed type I fibre predominance. Basophilic accumulations, which stained intensely with the NADH-TR reaction, were present in both fibre types. Electron microscopy revealed that these consisted of tightly packed parallel tubular arrays. These varied somewhat in their ultrastructural appearance and were classified accordingly as type I, II, and III tubular structures. The tubular aggregates appear to be derived from the sarcoplasmic reticulum. This report further supports the evidence of a distinct clinico-pathological entity of genetic origin.     

Detection of herpes simplex infection in cytologic smears

We compare the results of direct immunofluorescence (IF) with cytology (Papanicolaou's stains) for diagnosis of herpes simplex infection. Thirty smears were examined. Yellow-green fluorescence was seen in 17 smears. Only eight of these smears had diagnostic cytology, and nine of the smears with positive fluorescence had none (four) to minimal (five) cytologic changes, suggesting that direct IF is a much more sensitive method for diagnosis of herpes simplex infection in cytologic smears.     

Insoluble immune complex-stimulated neutrophil leukotriene B4 production is dependent on Fc gamma RII and Fc gamma RIII and independent of pertussis toxin-sensitive signal transduction pathways.

Leukotriene B4 (LTB4) release initiated by interaction of immune complexes (ICs) with Fc gamma RII and Fc gamma RIII receptors on human neutrophils was studied using well-defined complexes. Immune complexes consisting of polyclonal rabbit antibody to human albumin were prepared at equivalence (insoluble complex) and at five times antigen excess (soluble complex). Incubation of human neutrophils with soluble and insoluble ICs led to the synthesis of LTB4 from endogenous arachidonic acid (AA). LTB4 release induced by ICs was markedly inhibited by monoclonal antibodies against either Fc gamma RII or Fc gamma RIII receptor. Treatment of neutrophils with pertussis toxin significantly inhibited the release of LTB4 induced by soluble ICs. However pertussis toxin treatment minimally inhibited the LTB4 release induced by insoluble ICs. Crosslinking of either Fc gamma RII and Fc gamma RIII receptors on neutrophil surfaces induced LTB4 release. This is the first experimental observation showing that both Fc gamma RII and Fc gamma RIII directly induce neutrophil LTB4 metabolism in the absence of exogenous AA. These studies also suggest the involvement of novel pertussis toxin insensitive signal transduction pathways in insoluble ICs stimulation of neutrophils.     

Primary proliferative and cytotoxic T-cell responses to HIV induced in vitro by human dendritic cells.

In earlier studies, primary proliferative and cytotoxic T-cell (CTL) responses to influenza virus were produced in vitro by using mouse dendritic cells (DC) pulsed with virus or viral peptide as the stimulus for syngeneic T cells in 20-microliters hanging-drop cultures. We have now adapted this system for producing primary responses with cells from non-immune donors to produce primary proliferative and CTL responses to human immunodeficiency virus I (HIV) and to HIV peptides in vitro using cells from normal human peripheral blood. All donors in this study were laboratory personnel with no history of HIV infection. DC enriched from peripheral blood were exposed to HIV in vitro and small numbers were added to T lymphocytes in 20-microliters hanging drops. Proliferative responses to virus-infected DC were obtained after 3 days in culture. After 6 days, CTL were obtained that killed virus-infected autologous--but not allogeneic--phytohaemagglutinin (PHA)-stimulated blast cells. Proliferative and CTL responses were obtained using cells from 14 random donors expressing a spectrum of major histocompatibility complex (MHC) types but the CTL, once produced, showed killing restricted by the MHC class I type. Treatment of cultures with monoclonal antibody (mAb) to CD4-positive cells at the beginning of culture blocked the development of both proliferative and CTL responses, but treatment after 5 days had no effect on the CTL activity. Treatment with MCA to CD8-positive cells at the beginning of culture did not block proliferation significantly, but treatment either before or after the 5-day culture period blocked CTL responses. Collaboration between proliferating CD4-positive cells and CD8-positive cells may thus be required to produce CTL of the CD8 phenotype. DC exposed to HIV also produced CTL that killed autologous blast cells pulsed with gp120 envelope glycoprotein. However, DC infected with whole virus did not produce CTL that lysed target cells pulsed with a synthetic peptide, which included a known T-cell epitope of gp120 (representing amino acids 111-126). DC pulsed with gp120 were a poor stimulus for the development of CTL. In contrast, DC pulsed with the peptide (111-126) stimulated both proliferative and CTL responses. The latter killed not only target cells pulsed with the peptide itself or with gp120 but also killed virus-infected autologous blast cells. CTL were again obtained reproducibly with this peptide using donors expressing a spectrum of MHC types.(ABSTRACT TRUNCATED AT 400 WORDS)     

Autoradiographic evidence for beta-adrenergic receptors on capsaicin-sensitive primary afferent terminals in rat spinal cord

Specific [3H]dihydroalprenolol binding sites are enriched in the dorsal grey matter of rat spinal cord. Neonatal capsaicin treatment, known to cause a permanent loss of a population of primary afferent neurones, caused a significant loss of specific [3H]dihydroalprenolol binding sites from laminae of the dorsal horn. These results suggest that capsaicin-sensitive primary afferent terminals may bear presynaptic beta-adrenergic receptors.     

Frequency of cytokine polymorphisms in populations from western Europe,Africa, Asia,the Middle East and South America

PCR-SSOP identification procedures for IL-2, IL-6, IL-10, TNF-alpha and TNF-beta cytokine polymorphisms have been developed. Application of the procedures to a range of diverse geographically distributed populations has identified ethnic differences within the groups studied. Five populations were investigated, Northern Ireland, South African Zulu, Omani, Singapore Chinese and Mexican Mestizos.     

Vagal-enteric interface: vagal activation-induced expression of c-Fos and p-CREB in neurons of the upper gastrointestinal tract and pancreas

Many gastrointestinal and pancreatic functions are under strong modulatory control by the brain via the vagus nerve. To start identifying location and neurochemical phenotype of the enteric neurons receiving functional vagal efferent input, we activated vagal preganglionic neurons either by electrical or chemical stimulation and examined the expression of phosphorylated CREB (c-AMP response element binding protein) and the immediate early gene c-Fos. There was no spontaneous expression of both markers in the pancreas and considerable spontaneous expression of p-CREB but not Fos in the upper GI-tract. Unilateral electrical vagal stimulation-induced p-CREB was found in 40% of neurons in the head of the pancreas. Fos expression was found in 70-90% of neurons in the esophagus and stomach, in 20-30% of myenteric plexus neurons and 5-15% in submucosal neurons of the proximal duodenum. Double-labeling experiments showed that a majority of pancreatic neurons and about 25-35% of neurons in the stomach and duodenum contain NADPH-diaphorase and that many of these receive functional vagal input. Other neurons that can be vagally activated contain gastrin-releasing peptide or calretinin. Chemical stimulation of the dorsal surface of the caudal brainstem with the stable TRH analog RX77368 resulted in selective activation of vagal efferents with expression of Fos in a small number of gastric myenteric plexus neurons. The results demonstrate the suitability of this method to investigate magnitude and local distribution of vagal input to the enteric nervous system as well as specificity of its neurochemically coded pathways. They represent the first step in the identification of function-specific units of parasympathetic vagal outflow.     

Neonatal impact of leukemia inhibitory factor on neurobehavioral development in rats

Cytokines have been implicated in the etiology or pathology of various psychiatric diseases of developmental origin such as autism and schizophrenia. Leukemia inhibitory factor (LIF) is induced by a variety of brain insults and known to have many influences on mature and immature nervous system. Here, we assessed the neurobehavioral and pathological consequences of peripheral administration of LIF in newborn rats. Subcutaneous LIF injection induced STAT3 phosphorylation in many brain regions and increased glial fibrillary acidic protein (GFAP) immunoreactivity in the neocortex, suggesting that LIF had direct effects in the central nervous system. The LIF-treated rats displayed decreased motor activity during juvenile stages, and developed abnormal prepulse inhibition in the acoustic startle test during and after adolescence. They displayed normal learning ability in active avoidance test, however. Brain neuronal structures and startle responses were grossly normal, except for the cortical astrogliosis during neonatal LIF administration. These results indicate that LIF induction in the periphery of the infant has a significant, but discrete impact on neurobehavioral development.