Experimental subcutaneous granulomas in sheep with Dermatophilus-like microorganisms from porcine tonsil

The pathogenicity of the Dermatophilus-like microorganisms from porcine tonsil and the light and electron microscopic findings were studied with adult ewes. The early lesions were abscessess and advanced ones were granulomas after the subcutaneous inoculation. The granulomas were composed of the central bacterial colonies and the layers of the neutrophils, epithelioid cells and giant cells, and peripheral connective tissues. Epithelioid cells and giant cells were identified by the large euchromatic nuclei, abundant organelles and interdigitation of the blunt pseudopods in the ultrastructure. The lesions were very similar to subcutaneous granulomas in sheep and cattle due to Dermatophilus congolensis (atypical dermatophilosis), actinomycosis and nocardiosis.     

Subcutaneous clostridial infection in Adelie penguins in Hope Bay,Antarctica

During the 2000–2001 breeding season in Hope Bay, Antarctica, two adult Adelie penguins were found dead with lesions compatible with subcutaneous clostridial infection. Clostridium cadaveris was isolated from the musculature and the subcutaneous tissue of one of these two penguins, whereas Clostridium sporogenes was isolated from the subcutaneous tissue of the other penguin. Escherichia coli and Staphylococcus spp. were isolated from both animals. This is the first report of subcutaneous clostridial infection in Antarctic Adelie penguins.     

Protective effect of prior immunization on ocular paracoccidioidomycosis in guinea pigs

The present study reproduced the experimental model of ocular paracoccidioidomycosis in guinea pigs, by the intracardiac inoculation of yeast-forms of P. brasiliensis. Ocular involvement was observed in 80% of the infected animals. The uvea, ciliary body, choroid, iris, lids and the conjunctiva were the structures most commonly affected. To protect the animals against the infection, an immunization protocol was standardized utilizing a P. brasiliensis soluble antigen in Freund's complete adjuvant, administered weekly, during 3 weeks, by the subcutaneous route. Two weeks later, previously immunized guinea pigs were challenged by the intracardiac route with yeast-forms of P. brasiliensis (vaccinated group). When compared with a control group (infection in the absence of prior immunization), the vaccinated animals developed higher levels of anti-P. brasiliensis cellular and humoral immune response and a three times lower frequency of ocular involvement (85.7% vs 28.5%). In addition, the ocular lesions were significantly more localized and contained less fungal cells. The data demonstrated that the subcutaneous immunization was effective in decreasing the frequency and extent of ocular lesions, as well as in blocking fungal multiplication.     

Reevaluation of the teleomorph of the genus Histoplasma by ubiquinone systems

A study was performed to investigate the ability of Streptomyces griseus to cause experimental mycetoma in the skin and in the foot pads of mice. The lesions appeared as palpable subcutaneous nodules discharging pale yellow cheesy pus and granules of S. griseus. The inoculated foot pads of the mice also developed nodular lesions which later became oedematous with bone destruction and fibrosis.     

Intranasal Immunization with Yersinia enterocolitica O:8 Cellular Extract Protects against Local Challenge Infection

Yersinia enterocolitica is enteropathogenic for humans and rodents. Immune protection from oral and respiratory pathogens may be most effectively elicited following intranasal (i.n.) vaccination. An experimental murine intranasal challenge model was used to evaluate the immunogenicity of a Y. enterocolitica O:8 cellular extract (CE) in mucosa. This antigenic preparation has demonstrated to induce protection by subcutaneous immunization. Mice were immunized intranasally with two doses of CE. Immunized and nonimmunized animals were challenged with 5×10⁶ colony-forming units (CFU) by nasal infection. Antibodies in serum and bronchoalveolar lavage (b.a.l.) fluid were assessed before and 48 hr after challenge. The CFU were determined by analysis of lung homogenate samples. The CE immunization induced significant b.a.l.-specific IgA and IgG, and serum-specific IgG, IgA and IgM. Histopathological studies 24 and 48 hr postchallenge demonstrated that immunization protected against progressive lesions resulting from Y. enterocolitica invasion of the pulmonary mucosa. The CFU in the lungs showed that CE immunization led to significant clearance as compared to the bacterial level in nonimmunized controls. From the results obtained, it can be concluded that CE can induce local and systemic immunity and protect against nasal infection.     

Experimental Pathogenicity of a Clinical Isolate of <Emphasis Type="Italic">Trichosporon dermatis</Emphasis> in a Murine Model

The pathogenicity of Trichosporon dermatis isolated from skin lesions of a patient has been examined in mice. Balb/c mice were treated with two intraperitoneal injections of 100 mg/kg cyclophosphamide on days 4 and 1 and one subcutaneous injection of 10 mg/kg dexamethasone on day 1 pre-inoculation, and then challenged with 0.2 ml T. dermatis inoculum (1 × 10⁸ CFU/ml) by topical application on an abrasive wound in the dermabrasive group and by hypodermic injection in the subcutaneous group. In the intravenous group, 0.2 ml of high (1 × 10⁸ CFU/ml) or low (1 × 10⁷ CFU/ml) inoculum was injected into the tail vein. Histopathology and inverse fungal culture were performed on the skin lesion and viscera, and renal fungal burden was also determined. Inoculated sites developed localized infections after dermabrasive and subcutaneous challenge in all mice, but the maximum area of skin lesions, and number of positive cultures from the lesions, were higher for immunocompromised mice. In the intravenous group, all immunocompetent animals survived during the four-week period, whereas 100 and 70% of immunocompromised animals died by 3 and 5 days in the high and low-inoculum groups, respectively. The incidence of disseminated infection and the renal fungal burden of immunocompromised mice were higher than those of immunocompetent mice. Our results demonstrate that subcutaneous and intravenous injection of T. dermatis can successfully establish cutaneous and systemic infection models in immunocompromised mice, with the kidney and lung being most susceptible.     

The effect of prednisolone trimethylacetate on the pathogenicity of dermatophilus congolensis to white mice

Albino mice were successfully infected intravenously, subcutaneously, intraperitoneally and on the intact and scarified skin with Dermatophilus congolensis. Various gross lesions were observed. Large subcutaneous nodules were produced in mice that were injected subcutaneously. Lesions involving the internal organs were obtained in mice that had been injected intravenously and intraperitoneally in addition to microabsessation and scab formation on the tails of those that were injected intravenously. The application of D. congolensis on scarified skin resulted in scab formation covering the whole area while its application on non-scarified skin produced isolated lesions. The organism was isolated in pure culture from exudate, pus and scab material obtained from lesions. Severe histopathological changes were noted in sections prepared from the lesions. Premedication of mice with prednisolone trimethylacetate increased the severity of the experimentally induced lesions.     

Identification of immunoreactive proteins of Dirofilaria immitis and D. repens recognized by sera from patients with pulmonary and subcutaneous dirofilariosis

Human pulmonary and subcutaneous dirofilariosis caused by Dirofilaria immitis and Dirofilaria repens are worldwide diagnosed with increasing frequency. These species are responsible for the development of benign pulmonary and subcutaneous nodules, respectively, that can be confused with lung or cutaneous cancer. The aim of the present work was to identify D. immitis and D. repens proteins differentially recognized by serum samples from individuals with human pulmonary and subcutaneous dirofilariosis, using two-dimensional electrophoresis and mass spectrometry. Twenty-three immunoreactive proteins of D. immitis and 15 of D. repens were identified. The results point to the existence of differential antigenic recognition in each species, both in the number and type of proteins recognized. Individuals with pulmonary dirofilariosis recognized, on the proteome of D. immitis, among others, different isoforms of 6 enzymes involved in glycolysis, 3 redox-related proteins with antioxidant capacity and 3 heat shock proteins. Individuals with subcutaneous dirofilariosis recognized on the proteome of D. repens only 3 glycolytic enzymes, one protein involved in redox processes and one heat shock protein. These data suggest that in cases of pulmonary dirofilariosis there exists a wider recognition of immunoreactive D. immitis proteins related to key survival processes, such as energy generation, the struggle against oxidative stress and molecular repair, than in cases of human subcutaneous dirofilariosis against D. repens. This could contribute to explain the differences described in the capacity of D. immitis and D. repens development and in the frequency of occurrence of pulmonary and subcutaneous dirofilariosis in the human host.     

Hepatocyte growth factor ameliorates dermal sclerosis in the tight-skin mouse model of scleroderma

The tight-skin (TSK/+) mouse, a genetic model of systemic sclerosis (SSc), develops cutaneous fibrosis and defects in pulmonary architecture. Because hepatocyte growth factor (HGF) is an important mitogen and morphogen that contributes to the repair process after tissue injury, we investigated the role of HGF in cutaneous fibrosis and pulmonary architecture defects in SSc using TSK/+ mice. TSK/+ mice were injected in the gluteal muscle with either hemagglutinating virus of Japan (HVJ) liposomes containing 8 μg of a human HGF expression vector (HGF-HVJ liposomes) or a mock vector (untreated control). Gene transfer was repeated once weekly for 8 weeks. The effects of HGF gene transfection on the histopathology and expression of tumor growth factor (TGF)-β and IL-4 mRNA in TSK/+ mice were examined. The effect of recombinant HGF on IL-4 production by TSK/+ CD4⁺ T cells stimulated by allogeneic dendritic cells (DCs) in vitro was also examined. Histologic analysis revealed that HGF gene transfection in TSK/+ mice resulted in a marked reduction of hypodermal thickness, including the subcutaneous connective tissue layer. The hypodermal thickness of HGF-treated TSK/+ mice was decreased two-fold to three-fold compared with untreated TSK/+ mice. However, TSK/+ associated defects in pulmonary architecture were unaffected by HGF gene transfection. HGF gene transfection significantly inhibited the expression of IL-4 and TGF-β1 mRNA in the spleen and skin but not in the lung. We also performed a mixed lymphocyte culture and examined the effect of recombinant HGF on the generation of IL-4. Recombinant HGF significantly inhibited IL-4 production in TSK/+ CD4⁺ T cells stimulated by allogeneic DCs. HGF gene transfection inhibited IL-4 and TGF-β mRNA expression, which has been postulated to have a major role in fibrinogenesis and reduced hypodermal thickness, including the subcutaneous connective tissue layer of TSK/+ mice. HGF might represent a novel strategy for the treatment of SSc.     

Cryptococcal dermotropism in the rhesus monkey

An unexpected result was obtained from the intravenous injection ofCryptococcus neoformans into rhesus monkeys. We had sought to develop pulmonary lesions, but instead cutaneous lesions occurred.Each of seven monkeys received five millionCryptococcus neoformans cells intravenously. On the ninth to fifteenth day an acneform cutaneous eruption and nodular sub-cutaneous swellings appeared in all the monkeys and disappeared spontaneously by about the thirtieth day. Biopsies on the ninth day showed free cryptococcal cells with polymorphonuclear response. Biopsy on the twenty-second day showed persistent abscesses with a surrounding shell of giant cells containing shrunken and partially digested cryptococcal organisms. Chest x-rays on the fifteenth day showed no pulmonary lesions. None of the monkeys died spontaneously. When they were sacrificed between the 37th and 102nd day, the lungs were devoid, both grossly and microscopically, or cryptococcal lesions. However, a fulminating cryptococcosis of the right bulbus oculi was found on one monkey and a minute cryptococcal granuloma in the brain of another. Skin testing with cryptococcin was negative before the experimental injection, but became positive at three weeks. Reinjection ofC. neoformans i.v. in one of the monkeys resulted in a second crop of dermal lesions, though of smaller extent and of shorter duration.The 39.5° C temperature of the rhesus monkey may be a factor in the paucity of pulmonary lesions and the development of cutaneous ones.Aided by Grant AI 08454, Department of Health, Education and Welfare, U.S. Public Health Service. Presented at the Annual Meeting of the American Society for Microbiology, Minneapolis, Minn., May 2–7, 1971.     

Superficial contact cryoablation attenuates experimentally created lung air leakage

Previously, we, and others found that cryoablation on normal lung produced localized pulmonary hemorrhage and edema, causing obliteration of air space. Therefore, we hypothesized that lung air leakage may be diminished by this procedure. In the present study, we examined if cryoablation can attenuate experimentally created lung air leakage. Male domestic pigs (n = 4) underwent a thoracotomy. The lung was resected approximately 5 mm in diameter and 1 mm in depth to create air leakage lesions. An argon gas cryoprobe with a copper plate attached to its tip was used to cryoablate the lesions superficially. After cryoablation, the positive airway pressure that produced macroscopic bubbles from each lesion site was compared between cryoablated and untreated lesions. Also, cryoablation of the lung surface was carried out in male Donryu rats (n = 20) which were sequentially sacrificed to observe the histological changes over a time course. In the pigs, the air leakage pressure was significantly increased with cryoablation (40 cmH₂O <) compared to no treatment (19 ± 5 cmH₂O) (p = 0.021, Mann–Whitney U test). Histologically, cryoablation produced acute pulmonary hemorrhage and edema. In the rats, the region with extensive hemorrhage progressed to fibrosis in 1 month, and the areas with edema recovered. This study provides supportive evidence that cryoablation has the potential to stop air leakage from surface pulmonary injury. This procedure may provide a useful adjunct to surgical resection for spontaneous pneumothorax, and the control of air leakage from dissected raw lung surfaces during lung resection.     

The Importance of a Proper Aetiological Diagnosis in the Management of Patients with Invasive Mycoses: A Case Report of a Brain Abscess by <Emphasis Type="Italic">Scedosporium apiospermum</Emphasis>

Scedosporium apiospermum is a saprobic fungus responsible for many different clinical manifestations. Although it affects mostly immunocompromised patients, pulmonary and disseminated scedosporiosis have also been reported in immunocompetent subjects. It often causes subcutaneous mycetoma, despite its preferential tropism to CNS. The authors describe a fatal case of a S. apiospermum brain abscess in a 58-year-old female. She was affected by chronic liver disease and idiopathic pulmonary fibrosis and had been treated with corticosteroid therapy for a long time. She recovered in a neurosurgery unit, wherein TC scan and cerebral MRI revealed an expansive left temporo-parietal process with vasogenic oedema. A stereotactic puncture of the lesion was carried out, and pus of brain abscess was evacuated. Empirical antifungal therapy was initiated with liposomal amphotericine B based on the clinical suspicion of Zygomycetes infection; after 3 days, posaconazole was added. The correct aetiological diagnosis arrived too late and the patient was treated with no specific therapy. This fatal case confirms the necessity of having a fast and correct aetiological diagnosis to improve the patient’s outcome.     

Red grain mycetoma of the scalp (Actinomadura pelletieri). A case report from India

A case of red grain mycetoma on the scalp is described. The disease, caused by Actinomadura pelletieri, is extremely rare in this part of the world, and from India this is perhaps the first case with scalp involvement. The lesion showed satisfactory response to partial excision followed by chemotherapy with streptomycin.Mycetoma is a clinical syndrome of localized indolent deforming tumid lesions and sinuses involving the cutaneous and subcutaneous tissues (8). The disease is caused by two groups of agents; one bacterial and the orher fungal and is accordingly classified as actinomycotic and eumycotic mycetoma respectively. The lesions discharging fungal microcolonies referred to as grains usually occur on the foot or the hand. Occasionally, the lesions have been seen on the axillary (3) and the thoracocervical region (6). The involvement of the scalp is extremely rare. Reddy et al (7) in their study of 50 cases from Southern India, found only one instance of a scalp infection, the causative agent being A. madurae. We report herein on a patient with classical lesions of mycetoma on the scalp as a result of Actinomadura pelletieri infection.     

Spontaneous pulmonary adenocarcinoma and subcutaneous cavernous hemangiomas arising in a squirrel monkey (Saimiri sciureus)

Benign and malignant pulmonary tumors have been reported in both Old World and New World monkeys but are uncommon. Hemangiomas are also rarely reported in nonhuman primates. Here we present a case of two primary neoplasms (a papillary adenocarcinoma of bronchioloalveolar origin and multiple cavernous subcutaneous hemangiomas) arising in an aged squirrel monkey (Saimiri sciureus).     

Experimental pulmonary paracoccidioidomycosis in mice: Morphology and correlation of lesions with humoral and cellular immune response

The present paper describes a murine model for pulmonary paracoccidioidomycosis injecting 6×10⁵ yeast forms ofParacoccidioides brasiliensis (Pb) by the direct intratracheal route. The sequential histopathology of lung and dissemination lesions together with humoral (immunodiffusion test) and cellular immune response (footpad test and macrophage inhibition factor assay — MIF assay) were investigated since the 1^st to the 360^th day after infection. All infected animal showed pulmonary Pbmycosis up to Day 30; onwards the lesions subsided being found only in one mouse at Day 360. Dissemination lesions were observed in paratracheal and cervical lymph nodes in 9 out of 68 infected animals. Histologically early lesions were rich in polymorphonuclear cells and evolved to a macrophage desquamative pneumonitis at Day 15 and to typical epithelioid granulomata from Day 30 up to Day 360. Specific precipitating antibodies were first detected 15 days after infection, peaked from Day 30 to 60 and were not observed at Day 360. Significant cell-mediated immunity to Pb was noted at Day 15 with the peak reaction at Day 60 and 90.The intratracheal route represents a highly effective way of infecting mouse with Pb. This experimental pulmonary Pbmycosis is a granulomatous inflammation which courses with specific humoral and cellular immune response. It may be a good tool for further investigation in the pathogenesis and natural history of the disease.     

Pulmonary actinomycosis in two chamois (<Emphasis Type="Italic">Rupicapra rupicapra</Emphasis>)

Actinomycosis is a widespread non-contagious infectious condition, occurring both in animals and humans, caused by bacteria of the Actinomyces genus. In this report, two cases of pulmonary actinomycosis occurring in two wild chamois from northern Italy are described. In both cases, evidence of lung pyogranulomatous lesions with intra-lesional sulphur granules composed of filamentous, acid fast negative bacteria that stain positive for gram and periodic acid Schiff (PAS) leads to the etiological confirmation of pulmonary actinomycosis.     

Sequential pathological studies in goats infected intratracheally withAspergillus fumigatus

Intratracheal inoculation of goats withAspergillus fumigatus spores resulted in the development of characteristic gross and microscopic lesions. The lesions were restricted to lungs and there was no dissemination of infection to other tissues of the body except liver in one goat 16 days after infection. The experiment was continued for 37 days. Gross changes in lungs were observed up to the 24th day post-infection. The lesions, in general, included congestion and oedema in the first 6 days followed by the development of varying greyish-white nodules in the lungs. Microscopic changes consisted of granulomatous reaction with well developed granulomas in lungs. Hyphae and conidiophores with fruiting bodies ofAspergillus fumigatus could be demonstrated in sections up to 24 days of infection. Reisolation of the fungus consistently was achieved up to 24 days. It is concluded that intratracheal inoculation ofAspergillus fumigatus spores in goats leads to pulmonary aspergillosis up to 24 days.     

Protection against Escherichia coli O157:H7 challenge by immunization of mice with purified Tir proteins

Enterohemorrhagic Escherichia coli (EHEC) O157:H7 infections cause serious public health problems worldwide. The translocation intimin receptor (Tir) is responsible for adhesion and attaching and effacing lesions. In the current study, we used a mitomycin-treated mouse model to evaluate the efficacy of subcutaneous vs intranasal administration of the recombinant Tir as vaccine. Following immunization, mice were infected with E. coli O157:H7 and faces were monitored for shedding. Mice immunized intrasally with purified Tir proteins produced higher IgG and IgA titers in serum and feces, resulting in significant reductions in fecal shedding of EHEC O157 and higher a survival rate (92.9%), compared with subcutaneous or control immunizations. These results demonstrate the potential for the use of Tir proteins in mucosal vaccine formulations to prevent colonization and shedding of E. coli O157:H7. Therefore, purified Tir protects mice against EHEC challenge after intranasal immunization and is worth further clinical development as a vaccine candidate.     

Preneoplastic lesions of the lung

Lung cancer is the leading cause of cancer deaths worldwide. If we can define and detect preneoplastic lesions, we might have a chance of improving survival. The World Health Organization has defined three preneoplastic lesions of the bronchial epithelium: squamous dysplasia/carcinoma in situ; atypical adenomatous hyperplasia; and diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. These lesions are believed to progress to squamous cell carcinoma, adenocarcinoma and carcinoid tumors, respectively. In this review we summarize the data supporting the preneoplastic nature of these lesions, and delve into some of the genetic changes found in atypical adenomatous hyperplasia and squamous dysplasia/carcinoma in situ.     

Fine needle aspiration of subcutaneous masses caused by Aspergillus: a report of 2 cases

BACKGROUND: Fine needle aspiration biopsy is a well-established method for dijfrrentiation of infective from neoplastic lesions. Varions infective agents, such as mycobacteria, leishmaniasis and microfaria can be diagnosed from aspirates, but there are few case reports on fungal infections in aspirates. Cytologic diagnosis of Aspergillus has occasionally occurred on sputum, pulmonary samples, vaginal secretions, endometrial washings and maxillary sinus specimens. One case of hepatic and subcutaneous masses was diagnosed as Aspergillus by fine needle aspiration and confirmed by culture and histology. CASES: Two cases of subcutaneous aspergillosis were diagnosed by fine needle aspiration and confirmed by culture and histology. CONCLUSION: Fine needle aspiration cytology is a rapid, sensitive and important method of diagnosing Aspergillus and provides a rapid diagnosis, which may be life saving in an immunocompromised patient.