Quantitative and Topographic Analysis by Immunohistochemical Expression of Ghrelin Gastric Cells in Patients with Morbid Obesity

PURPOSE

The cellular distribution of ghrelin positive cells is not well defined. The aim of the study is to quantify and determine the distribution of ghrelin cells in gastric mucosa in patients with morbid obesity and relate this finding to gender, comorbidities, gastritis, and plasmatic levels of acyl and desacylghrelin before and after laparoscopic sleeve gastrectomy.

PATIENT AND METHODS

We performed a study on 61 patients with BMI≥50 kg/m² operated by laparoscopic sleeve gastrectomy. Three gastric regions were analyzed by histopathology and immunohistology. Blood sample was taken before surgery, and at 6 and 12 months post-surgery, to study the plasma levels of ghrelin isoforms.

RESULTS

Ghrelin cells are present in all regions of the gastric mucosa, with a greater number in the body and the fundus. Difference was found in the antrum between male and female patients (p=0.018). Patients with arterial hypertension also showed a lower level of cells in antrum (p<0.05). Acylghrelin levels after surgery were significantly lower (32.83+5.6 pg/mL to 10.09+11.8 pg/mL, p<0.05). Values of desacylghrelin tended to decrease but no significant variation was observed (207.4+39.3 pg/mL to 188.84+52.3 pg/mL).

CONCLUSION

Our patients show ghrelin cells in all areas of the stomach. Gender, comorbidities, and gastritis are determinant on gastric ghrelin-producing cells distribution.

A possible role for fumagillin in cellular damage during host infection by Aspergillus fumigatus

Virulence mechanisms of the pathogenic fungus Aspergillus fumigatus are multifactorial and depend on the immune state of the host, but little is known about the fungal mechanism that develops during the process of lung invasion. In this study, microarray technology was combined with a histopathology evaluation of infected lungs so that the invasion strategy followed by the fungus could be described. To achieve this, an intranasal mice infection was performed to extract daily fungal samples from the infected lungs over four days post-infection. The pathological study revealed a heavy fungal progression throughout the lung, reaching the blood vessels on the third day after exposure and causing tissue necrosis. One percent of the fungal genome followed a differential expression pattern during this process. Strikingly, most of the genes of the intertwined fumagillin/pseurotin biosynthetic gene cluster were upregulated as were genes encoding lytic enzymes such as lipases, proteases (DppIV, DppV, Asp f 1 or Asp f 5) and chitinase (chiB1) as well as three genes related with pyomelanin biosynthesis process. Furthermore, we demonstrate that fumagillin is produced in an in vitro pneumocyte cell line infection model and that loss of fumagillin synthesis reduces epithelial cell damage. These results suggest that fumagillin contributes to tissue damage during invasive aspergillosis. Therefore, it is probable that A. fumigatus progresses through the lungs via the production of the mycotoxin fumagillin combined with the secretion of lytic enzymes that allow fungal growth, angioinvasion and the disruption of the lung parenchymal structure.

Combined antifungal therapy against systemic murine infections by rare Cryptococcus species

Cryptococcus albidus and Cryptococcus laurentii are uncommon species of this genus that in recent decades have increasingly caused opportunistic infections in humans, mainly in immunocompromised patients; the best therapy for such infection being unknown. Using a murine model of systemic infection by these fungi, we have evaluated the efficacy of amphotericin B (AMB) at 0.8 mg/kg, administered intravenously, fluconazole (FLC) or voriconazole (VRC), both administered orally, at 25 mg/kg and the combination of AMB plus VRC against three C. albidus and two C. laurentii strains. All the treatments significantly reduced the fungal burden in all the organs studied. The combination showed a synergistic effect in the reduction in fungal load, working better than both monotherapies. The histopathological study confirmed the efficacy of the treatments.

Emmonsiellopsis, a new genus related to the thermally dimorphic fungi of the family Ajellomycetaceae

Two interesting fungi were isolated from fluvial sediments collected in the North of Spain. They were morphologically related to the thermally dimorphic fungi of the family Ajellomycetaceae, but the analysis of the internal transcribed spacer region of the rDNA, and the domains D1 and D2 of the 28S rRNA gene sequences confirmed that they were different from all the species described in that family. They were accommodated in the new genus Emmonsiellopsis as E. coralliformis sp. nov. and E. terrestris sp. nov. The two species are distinguished mainly by the maximum temper-ature of growth (up to 33 °C for E. coralliformis and to 42 °C for E. terrestris), the dendritic mycelium of E. coralliformis and the conidial ornamentation (verrucose in E. coralliformis and spinulose in E. terrestris). In addition, the phylogenetic data demonstrated that Ajellomyces griseus also represents a new genus within the Ajellomycetaceae, namely Helicocarpus. This new genus is easily distinguished by the lack of asexual morph, the production of brownish gymnothecial ascomata and oblate to lenticular, sparingly pitted ascospores. The proposal of both new genera was confirmed by the analysis of actin gene sequences.

Fungal prostatitis: an update

Prostate pathology is a daily occurrence in urological and general medical consultations. Besides hyperplasia and neoplastic pathology, other processes, such as infectious ones, are also documented. Their etiology is diverse and varied. Within the infectious prostatic processes, fungi can also be a specific cause of prostatitis. Fungal prostatitis often appears in patients with impaired immunity and can also be rarely found in healthy patients. It can result from a disseminated infection, but it can also be localized. Fungal prostatitis is a nonspecific and harmless process. Diagnosis is commonly made by fine needle aspiration cytology or by biopsy. A number of fungi can be involved. Although there are not many reported cases, they are becoming more frequent, in particular in patients with some degree of immunodeficiency or those who live in areas where specific fungi are endemic or in visitors of those areas. We present a comprehensive review of the various forms of fungal prostatitis, and we describe the morphological characteristics of the fungi more frequently reported as causes of fungal prostatitis. We also report our own experience, aiming to alert physicians, urologists and pathologists of these particular infections.

Therapies against murine Candida guilliermondii infection, relationship between in vitro antifungal pharmacodynamics and outcome

BACKGROUND

Candida guilliermondii has been recognized as an emerging pathogen showing a decreased susceptibility to fluconazole and considerably high echinocandin MICs.

AIMS

Evaluate the in vitro activity of anidulafungin in comparison to amphotericin B and fluconazole against different isolates of C. guilliermondii, and their efficacy in an immunosuppressed murine model of disseminated infection.

METHODS

The in vitro susceptibility of four strains against amphotericin B, fluconazole and anidulafungin was performed by using a reference broth microdilution method and time-kill curves. The in vivo efficacy was evaluated by determination of fungal load reduction in kidneys of infected animals receiving deoxycholate AMB at 0,8 mg/kg i.v., liposomal amphotericin B at 10 mg/kg i.v., fluconazole at 50 mg/kg, or anidulafungin at 10 mg/kg.

RESULTS

Amphotericin B and anidulafungin showed fungicidal activity, while fluconazole was fungistatic for all the strains. In the murine model, liposomal amphotericin B at 10 mg/kg/day was effective in reducing the tissue burden in kidneys of mice infected with any of the tested strains. However, amphotericin B, anidulafungin and fluconazole were only effective against those strains showing low MIC values.

CONCLUSIONS

Liposomal amphotericin B showed the higher activity and efficacy against the two strains of C. guilliermondii, in contrast to the poor effect of fluconazole and anidulafungin. Further studies with more isolates of C. guilliermondii representing a wider range of MICs should be carried out to assess whether there is any relationship between MIC values and anidulafungin efficacy.

Experimental murine acremoniosis: an emerging opportunistic human infection

Acremonium is an emerging fungal pathogen causing severe infections. We evaluated the virulence of three clinically relevant species within the genus, i.e., Acremonium kiliense (currently Sarocladium kiliense), Acremonium sclerotigenum-A. egyptiacum complex and Acremonium implicatum in a murine model of disseminated infection. Both immunocompetent and immunosuppresssed mice were infected with two inocula concentrations (2 × 10(6) and 2 × 10(8) conidia/animal) of two strains of each species. Tissue burden, mortality rate, histopathology and levels of (1→3)-β-D-glucan were used as virulence markers. None of the species of Acremonium tested was able to cause infection in immunocompetent mice. Conversely, severe infections were produced in immunocompromised mice, the spleen being the most affected organ. In general, the virulence of the Acremonium species tested was low, S. kiliense being the most virulent species.

Modest efficacy of voriconazole against murine infections by Sporothrix schenckii and lack of efficacy against Sporothrix brasiliensis

The efficacy of voriconazole (VRC) was evaluated against two strains of each of the two most common species causing sporotrichosis, Sporothrix schenckii sensu stricto and Sporothrix brasiliensis, using a murine model of disseminated infection. Voriconazole was administered at doses of 20 or 40 mg kg(-1) per day by gavage. The drug showed some efficacy, especially at 40 mg kg(-1) per day, in prolonging the survival and reducing fungal load in spleen and liver in mice infected with S. schenckii, whereas in animals infected with S. brasiliensis the drug did not work.

Virulence of Curvularia in a murine model

We have evaluated the virulence of two clinically relevant species of Curvularia; Curvularia spicifera and C. hawaiiensis, using an experimental model of disseminated infection in immunocompromised mice. Several inocula were tested over a range 1 × 10(3) -1 × 10(6) colony-forming units/animal. Both species had a similar behaviour, producing a high mortality. Tissue burden and histopathology studies demonstrated that lung was the organ most affected.

Efficacy of intrathecal administration of liposomal amphotericin B combined with voriconazole in a murine model of cryptococcal meningitis

Meningitis is one of the most fatal manifestations of cryptococcosis, even with specific treatment. Combination of a prompt diagnosis and appropriate therapy are critical to reduce the fungal load and the inflammatory response effects of the proliferation of yeast into the central nervous system (CNS). Mice with experimental acute meningitis caused by Cryptococcus neoformans were treated with liposomal amphotericin B (L-AmB) administered intrathecally (i.t.c.) at 0.006 mg/kg weekly or intravenously (i.v.) at 10 mg/kg daily or with voriconazole (VCZ) administered orally at 30 mg/kg per dose twice daily or with combinations of both drugs, i.e. L-AmB i.t.c.+VCZ or L-AmB i.v.+VCZ at the same doses as used in the monotherapies. All treatments significantly increased the survival of animals in comparison with the control group, with VCZ being less effective in comparison with all other treatments (P ≤ 0.012). All treatments, with the exception of VCZ (P=0.533), reduced fungal burdens in the brain in comparison with controls. The combination of L-AmB i.t.c.+VCZ showed a synergistic effect in the reduction of fungal load that was significantly superior to any tested therapy (P ≤ 0.039). Histologically, untreated animals showed a marked inflammatory response with massive fungal cells in the meninges, whilst treated animals showed a variable number of fungal cells in the CNS, with the exception of animals receiving L-AmB i.t.c.+VCZ in which neither yeasts nor inflammation were observed.

Histopathology and antifungal treatment of experimental murine chromoblastomycosis caused by Cladophialophora carrionii

OBJECTIVES

A murine model of chromoblastomycosis caused by Cladophialophora carrionii was used to compare the efficacy of posaconazole and voriconazole with that of terbinafine and itraconazole, the currently used drugs in the management of chromoblastomycosis.

METHODS

Athymic nude mice were infected with 2 × 10(7) cfu of a clinical isolate of C. carrionii. When typical lesions were established, treatments with posaconazole at 20 mg/kg/day, voriconazole at 20 mg/kg/day, itraconazole at 50 mg/kg/day or terbinafine at 250 mg/kg/day were initiated. Treatment efficacy was evaluated for 4 months by measuring the size of the lesions, observing any histopathological changes and culturing the excised tissue.

RESULTS

Posaconazole was the only drug that reduced the initial lesion size, while voriconazole and terbinafine reduced growth relative to controls.

CONCLUSIONS

This study suggests that the newer triazoles have potential in the treatment of chromoblastomycosis caused by C. carrionii.

Comparative virulence of three species of Exophiala in mice

The virulence of Exophiala dermatitidis, E. oligosperma and E. xenobiotica, three of the most common members of the genus that cause human infections, was evaluated using experimental models of disseminated infection in immunocompromised mice. Exophiala dermatitidis, and to a lesser extent E. oligosperma, were the two species causing the highest mortality, while mice infected with E. xenobiotica had the lowest mortality. Tissue burden and histopathology studies demonstrated the neurotropism of E. dermatitidis, while E. oligosperma and E. xenobiotica had a limited capacity for invading brain tissue. These models could be useful for testing new therapies against Exophiala infections.

Rectal inflammatory polyp in a child: an unusual case of polyparasitism

In recent years, parasitic diseases have increased especially in non-tropical or subtropical countries. We present a case of an 11-year-old boy from Guinea with a rectal polyp parasitized by Schistosoma haematobium and Trichuris trichiura. This parasitic association had never been reported in our country or in Europe.

Unusual morphologies of Cryptococcus spp. in tissue specimens: report of 10 cases

Ten cases of cryptococcosis due to unusual microscopic forms of Cryptococcus sp. observed over a twenty-eight year period (1981-2009) are presented. The most important clinicopathological and laboratory data are tabulated. The uncommon forms of cryptococcal cells given are: structures resembling germ tube (one case), chains of budding yeasts (one case), pseudohyphae (two cases) and nonencapsulated yeast-like organisms (eight cases). The diagnosis was based on the histopathological findings. The causative organism was isolated and identified in seven cases; five were due to C. neoformans, and two to C. gattii. In addition, the importance of using staining histochemical techniques - Grocott's silver stain (GMS), Mayer's mucicarmine stain (MM) and Fontana-Masson stain (FM) - in the diagnosis of cryptococcosis is argued.

Novel (60%) and recurrent (40%) androgen receptor gene mutations in a series of 59 patients with a 46,XY disorder of sex development

BACKGROUND

Androgen receptor (AR) gene mutations are the most frequent cause of 46,XY disorders of sex development (DSD) and are associated with a variety of phenotypes, ranging from phenotypic women [complete androgen insensitivity syndrome (CAIS)] to milder degrees of undervirilization (partial form or PAIS) or men with only infertility (mild form or MAIS).

OBJECTIVE

The aim of the study was to characterize the contribution of the AR gene to the molecular cause of 46,XY DSD in a series of Spanish patients.

SETTING

We studied a series of 133 index patients with 46,XY DSD in whom gonads were differentiated as testes, with phenotypes including varying degrees of undervirilization, and in whom the AR gene was the first candidate for a molecular analysis.

METHODS

The AR gene was sequenced (exons 1 to 8 with intronic flanking regions) in all patients and in family members of 61% of AR-mutated gene patients.

RESULTS

AR gene mutations were found in 59 individuals (44.4% of index patients), of whom 46 (78%) were CAIS and 13 (22%) PAIS. Fifty-seven different mutations were found: 21.0% located in exon 1, 15.8% in exons 2 and 3, 57.9% in exons 4-8, and 5.3% intronic. Twenty-three mutations (40.4%) had been previously described and 34 (59.6%) were novel.

CONCLUSIONS

AR gene mutation is the most frequent cause of 46,XY DSD, with a clearly higher frequency in the complete phenotype. Mutations spread along the whole coding sequence, including exon 1. This series shows that 60% of mutations detected during the period 2002-2009 were novel.

Radiofrequency-induced carcinogenesis: cellular calcium homeostasis changes as a triggering factor

The aim was to study the effects of radiofrequency (Rf) in a mice strain characterized by age-determined carcinogenesis of lymphatic tissues. Mice were treated with a 1?h/week Rf exposure for 4 months. A group submitted to sham exposure was used as control animals. The evolution of carcinogenesis was followed up to 18 months. The maximal life span of control mice was about 24 months. All dead animals were clinically and histologically examined to give an age-determined comparative quantification of the evolving carcinogenesis. A radiocalcium tracer method permitted the evaluation of Rf effects on transmembrane transport of extracellular calcium at 1 and 24 h after exposure. The determination of induced lipid peroxidation completed this second study. The findings show that Rf provoked an earlier general lymphocyte cell infiltration, formation of lymphoblastic ascites and extranodal tumours of different histological types, as well as an increased early mortality. The results suggest that in Rf-exposed mice, carcinogenesis may be induced earlier and with different pathological forms than in control animals. The modifications in cellular calcium homeostasis and the age-determined thymus involution appear to be important factors involved in this carcinogenesis process.

Thyroid involvement in disseminated zygomycosis by Cunninghamella bertholletiae: 2 cases and literature review

Thyroid involvement is very rare in disseminated zygomycosis. We describe two cases of thyroiditis due to Cunninghamella bertholletiae diagnosed though a necropsy study and the only five previous cases of thyroid zygomycosis reported in the literature are revised.

CYP2A6 activity in a healthy Spanish population: effect of age, sex, smoking, and oral contraceptives

This study was performed to assess the influence of age, sex, smoking, and contraceptive use on CYP2A6 activity. In the metabolism of caffeine, the conversion of 1,7 dimethylxanthine (17X) to 1,7 dimethiylurate (17U) is catalyzed primarily by CYP2A6. CYP2A6 phenotype was determined by the urinary ratio 17U:17X in the interval of 4-5 h after caffeine intake in 179 healthy white Spaniards (102 women and 76 men). There were 99 non-smokers and 80 smokers. Among women, 26 were taking oral contraceptives. The age was the most important predictive factor of CYP2A6 activity (P < 0.001) with older subjects having higher activity. The influence of the gender was more modest (P = 0.07) with women exhibiting borderline increased values of the CYP2A6 marker than men. Tobacco smoking did not affect CYP2A6 activity. However, the CYP2A6 marker resulted to be strongly related to the use of oral contraceptives. The women users of oral contraceptives had higher values of CYP2A6 marker than both women not taking oral contraceptives and men (P < 0.001 in both comparisons). The results indicate that age, oral contraceptive use, and possibly gender should be controlled in epidemiological studies dealing with CYP2A6 activity and its relationship with xenobiotics exposure and genetic or pathological factor.

Paracoccidiomicosis cutánea diseminada de importación

Paracoccidioidomycosis is a chronic progressive infection. It affects mainly the elderly and it is geographically limited to certain areas of Latin America. In Europe it is considered a rare imported infection. Here we report a case of paracoccidioidomycosis that occurred in a 27-year-old Ecuadorian patient living in Spain initially misdiagnosed as blastomycosis. The typical multi-budding yeast cells of Paracoccidioides brasiliensis were observed in Grocott stained samples. This case should alert Spanish mycologists, clinicians and pathologists about the possibility of patients who have travelled or lived outside Spain may suffer paracoccidioidomycosis or other imported mycoses.

Evaluation of health risks caused by radio frequency accelerated carcinogenesis: the importance of processes driven by the calcium ion signal

The acceleration of carcinogenesis, which was induced either by radio frequency radiation from a cellular telephone or by the ferric-ATP complex, was similar in a mouse strain characterized by age-determined carcinogenesis of lymphoid tissues. Organ hypertrophy, the presence of lymphoid blood and ascites, the development of solid tumours, and mortality were very different to those found in control animals. These results emphasize the role of calcium ion signal influx in the activation of oncogenes and the failure of thymus-determined immune defences.

Iron-radiofrequency synergism in lymphomagenesis

The parenteral iron administration effects on the acceleration of lymphomagenesis by radiofrequency exposure were investigated using an animal model that develops spontaneous lymphomas with ageing. Complementary studies of the in vivo uptake of 59Fe-labeled ferric gluconate and ferric-ATP complex showed differences ob absorption and excretion between both iron compounds. In vitro assays of their effects on calcium cellular uptake using a cell model and tissues homogenates showed a molecular structure-dependence. The current results (mortality, clinical and histopathological examinations) demonstrated a synergism between radiofrequency and ferric gluconate, and the increased risk of radiofrequency exposure when it is simultaneous to parenteral iron administration.

Combined action of uranium and stress in the rat

The effects of stress on the potential reproductive toxicity of long-term exposure to uranyl acetate dihydrate (UAD) were assessed in adult male rats. Six groups of animals were given UAD at 10, 20, and 40 mg/kg/day in the drinking water during 3 months. Animals in three of these groups were also subjected to restraint for 2 h/day during the same period. Control groups included restrained and unrestrained male rats not exposed to UAD. To evaluate the fertility, male rats were mated with untreated females for 2 weeks. Although body weight was not affected by uranium at any dose, there was a significant (not dose-related) decrease in the pregnancy rate. Moreover, spermatid number/testis was significantly decreased by uranium administration. Histopathological examination of the testes in rats killed after 3 months of treatment revealed few differences in the tubule and interstitial alterations (focal atrophy, binucleated cells) between control and uranium-exposed animals. The results of this investigation show that at the current UAD doses, restraint stress did not enhance the uranium-induced adverse effects on reproduction in male rats.

Strongyloides stercolaris infection mimicking a malignant tumour in a non-immunocompromised patient. Diagnosis by bronchoalveolar cytology

Autoinfective strongyloidiasis is often fatal in immunosuppressed patients or in immunocomprised hosts. An interesting case of Strongyloides stercolaris hyperinfection was seen in an immunocompetent patient. This report describes a case of fatal strogyloidiasis in a 79 year old man, who had suffered gastrointestinal discomfort for years, and who presented because of respiratory illness. A chest radiograph showed an irregular mass close to the mediastinum and interstitial infiltrates, but blood eosinophilia was not observed. Cytological examination of the samples obtained from bronchial aspiration and brushing identified several filariform larvae. Thus, cytology was essential for the correct diagnosis in this patient and is a very reliable method to diagnose lung parasitosis.

Efficacy of micafungin in combination with other drugs in a murine model of disseminated trichosporonosis

Using a murine model of disseminated infection caused by Trichosporon asahii, we have evaluated the efficacies of amphotericin B (AMB; 1 mg/kg of body weight/day), fluconazole (FLC; 20 mg/kg/twice a day), and micafungin (MFG; 5 mg/kg/twice a day). We tested these drugs alone and in combination (MFG with AMB and MFG with FLC). MFG with AMB showed a synergistic effect and demonstrated a higher degree of efficacy in prolonging survival and reducing the kidney fungal burden than either agent alone. The combination MFG with FLC was able to reduce significantly the kidney fungal burden in comparison to that achieved with either drug administered alone.

Cementoma of the fibula: imaging findings with histopathologic correlation and review of the literature

Bone tumors containing fibrous tissue and cementum-like spherules are typically found in the maxilla and mandible. However, such lesions are extremely infrequent in the long bones. We report the complete radiologic assessment of a cementoma of the fibula in a 42-year-old man. We also correlate the findings with data provided by histopathologic analysis, and review the English-language literature on tumors of long bones that may contain cementum-like material.

A novel murine model of cerebral scedosporiosis: lack of efficacy of amphotericin B

OBJECTIVES

Cerebral scedosporiosis is a life-threatening infection that is difficult to treat. The aim of this work was to develop a murine model of cerebral infection by Scedosporium apiospermum using intracranial inoculation and to use this model to evaluate the efficacy of amphotericin B deoxycholate and liposomal amphotericin B.

METHODS

Mice were rendered neutropenic by intraperitoneal cyclophosphamide and intravenous (iv) 5-fluorouracil administration. Animals were infected with iv or intracranial inoculation of 1 x 10(4), 5 x 10(4) or 5 x 10(5) cfu of a clinical strain of S. apiospermum. Tissue burden reduction was determined in kidneys and brain 4 days after the infection. Efficacy of amphotericin B and liposomal amphotericin B (0.8 mg/kg/day intraperitoneally and 40 mg/kg/day iv, respectively) was evaluated in neutropenic mice infected iv or intracranially with 5 x 10(4) cfu. Survival was analysed with the log-rank test. Fungal burden values of different groups were compared using the Mann-Whitney U-test.

RESULTS

In our model, intracranial infection produced a higher fungal load in the brain and a lower fungal load in the kidney than iv inoculation. Survival of animals infected intracranially and treated with amphotericin B or liposomal amphotericin B (mean survival time = 8.3 and 9.2 days, respectively) was not different from the control group (P=0.58 and 0.85, respectively).

CONCLUSIONS

We have developed a murine model of cerebral scedosporiosis, which may be useful for studying various pathological aspects of this infection and evaluating new therapeutic approaches. Amphotericin B and liposomal amphotericin B were unable to resolve the infection.

Endometrial coccidiosis

This report describes a case of granulomatous endometritis caused by coccidiosis in an immunologically uncompromised 63 year old patient. The glandular epithelium of the endometrium contained numerous intracytoplasmic cysts, corresponding to periodic acid Schiff positive and methenamine silver negative sporoblasts. The endometrial glands revealed reactive phenomena, such as eosinophilic and squamous glandular metaplasia and intraluminal desquamation. Non-necrotising epithelioid granulomata, lacking the presence of parasites, were present in the stroma. Although not detected in the stool examination, the organisms were probably Isospora belli. There was no evidence of other foci of the disease. Coccidiosis should be differentiated from the more commonly occurring coccidiomycosis.

Fusarium oxysporum as a multihost model for the genetic dissection of fungal virulence in plants and mammals

Fungal pathogens cause disease in plant and animal hosts. The extent to which infection mechanisms are conserved between both classes of hosts is unknown. We present a dual plant-animal infection system based on a single strain of Fusarium oxysporum, the causal agent of vascular wilt disease in plants and an emerging opportunistic human pathogen. Injection of microconidia of a well-characterized tomato pathogenic isolate (isolate 4287) into the lateral tail vein of immunodepressed mice resulted in disseminated infection of multiple organs and death of the animals. Knockout mutants in genes encoding a mitogen-activated protein kinase, a pH response transcription factor, or a class V chitin synthase previously shown to be implicated in virulence on tomato plants were tested in the mouse model. The results indicate that some of these virulence factors play functionally distinct roles during the infection of tomato plants and mice. Thus, a single F. oxysporum strain can be used to study fungal virulence mechanisms in plant and mammalian pathogenesis.

Childhood-onset congenital adrenal hyperplasia: long-term outcome and optimization of therapy

Congenital adrenal hyperplasia is a general term applied to several disorders caused by inherited recessive defects of cortisol synthesis. The most common form is 21-hydroxylase deficiency, accounting for 95% of cases. The classical forms have an incidence of one in 15,000 and the non-classical forms about one in 1,000. The classical or severe phenotype presents in the newborn period or early infancy with virilization and adrenal insufficiency, with or without salt-losing; the non-classical or mild phenotype presents in late childhood or early adulthood with signs of hyperandrogenism. This wide range of clinical expression is explained by genetic variation. Although there is a certain amount of genotype-phenotype correlation, discrepancies have been described. During the last 30 years there has been a substantial improvement in diagnosis and treatment of this disease, and patients with CAH now reach adulthood. Treatment of this condition is intended to reduce excessive corticotropin secretion and replace glucocorticoids and mineralocorticoids as physiologically as possible. Clinical management is often complicated by periods of inadequately treated hyperandrogenism, iatrogenic hypercortisolism, or both. Long-term consequences in adult life may include short stature, obesity, diminished bone mass, gonadal dysfunction with low fertility rates and psychosexual dysfunction in females. New treatment approaches are under investigation, such as the use of anti-androgens, inhibitors of estrogen production and adrenalectomy for severely resistant cases.