Stage T3a renal cell carcinoma: staging accuracy of CT for sinus fat, perinephric fat or renal vein invasion.

OBJECTIVE: To study the accuracy of CT for staging T3a (TNM 2009) renal cell carcinoma (RCC). METHODS: Unenhanced and nephrographic phase CT studies of 117 patients (male:female = 82:35; age range, 21-86 years) with T1-T3a RCC were independently reviewed by 2 readers. The presence of sinus or perinephric fat, or renal vein invasion and tumour characteristics were noted. RESULTS: Median (range) tumour size was 5.5 (0.9-19.0) cm; and 46 (39%), 16 (14%) and 55 (47%) tumours were pT1, pT2 and pT3a RCC, respectively. The sensitivity/specificity for sinus fat, perinephric fat and renal vein invasion were 71/79%, 83/76% and 59/93% (Reader 1) and 88/71%, 68/72% and 69/91% (Reader 2) with κ = 0.41, 0.43 and 0.61, respectively. Sinus fat invasion was seen in 47/55 (85%) cases with T3a RCC vs 16/55 (29%) and 33/55 (60%) for perinephric fat and renal vein invasion. Tumour necrosis, irregularity of tumour edge and direct tumour contact with perirenal fascia or sinus fat increased the odds of local invasion [odds ratio (OR), 2.5-3.7; p < 0.05; κ = 0.42-0.61]. Stage T3a tumours were centrally located (OR, 3.9; p = 0.0009). CONCLUSION: Stage T3a RCC was identified with a sensitivity of 59-88% and specificity of 71-93% (κ = 0.41-0.61). Sinus fat invasion was the most common invasive feature. ADVANCES IN KNOWLEDGE: Centrally situated renal tumours with an irregular tumour edge, inseparable from sinus structures or the perirenal fascia and CT features of tumour necrosis should alert the reader to the possibility of Stage T3a RCC (OR, 2.5-3.9).

Functional assessment in the multimodality imaging of pancreatic neuro-endocrine tumours.

Pancreatic neuroendocrine tumours comprise a heterogeneous group that are rare but could result in serious manifestations. Surgical excision provides the best approach to treatment but many patients may have small lesions that are difficult to detect, or present with wide spread disease by the time of diagnosis. In addition to clinical assessment and biochemical tests, imaging is a major factor in establishing the diagnosis. Cross-sectional imaging such as US, CT and MR, play a major role in the initial assessment. However, they may miss small lesions or metastatic spread. Functional Imaging became possible with the development of somatostatin receptor imaging using 111In-octreotide, which when combined with anatomical imaging could provide enhanced detection. A major improvement has been achieved by combining receptor and PET inaging through the use of 68Ga-DOTA complexes that have been shown to have a much better sensitivity than other imaging modalities and can provide the basis for radionuclide treatment with 90Y or 177Lu labelled with DOTA complexes.

The relationship between non-cognitive symptoms and functional impairment in Alzheimer's disease.

OBJECTIVE: Cognitive impairment is an important determinant for functional impairment in Alzheimer's disease. The role of non-cognitive symptom is uncertain. The objective of this study was to investigate the role of non-cognitive symptoms as predictive factors for functional outcome in A.D. METHODS: This was a retrospective study. Subjects were recruited from the Memory Clinic in Queen Mary Hospital over a two years period. Patients with diagnosis of probable A.D. by NINCDS-ADRDA were identified. Demographic data, Folstein Mini-Mental Status Examination (MMSE), Clinical Dementia Rating (CDR), Neuropsychiatric inventory (NPI), Barthel activities of daily living (ADL) as well as Lawton's Instrumental activities of daily living (IADL) were retrieved. RESULTS: 100 patients were identified. Univariate analysis identified statistically significant correlation between hallucination and disinhibition score with Barthel Index (r=-0.43, p <0.001; r=-0.30, p=0.002 respectively); hallucination and aberrant motor act score with Lawton's IADL (r=-0.21, p=0.038; r=-0.21, p=0.038). MMSE was statistical significantly correlated with the above two functional scores. NPI was not statistical significantly correlated with any one of the functional measures. Multivariate regression analyses showed that hallucination score was an independent predictive factors for the Barthel index but not for the Lawton's IADL. MMSE score was identified to be independent predictive factor for all functional measures. CONCLUSIONS: Global cognitive impairment and hallucination was an important independent predictive factor for functional outcomes. Screening hallucination during the course of A.D. would be helpful. Further studies are needed to show the benefit of treatment of hallucination on the improvement of functional outcomes.

Association of anurans with pathogenic fungi.

In a study of 450 Amazonian anurans, we isolated yeasts and yeast-like fungi from 54 animals (Bufo granulosus, B. marinus, Dendrophrynyscus sp., Hyla geographica, H. lanciformes, Ololygon rubra, Adenomera hylaedactyla, Eleutherodactylus fenestratus, Leptodactylus fuscus, L. ocellatus, L. pentadactylus). The internal organs of these animals did not show any macroscopic anomaly nor histopathology. We recovered 105 fungal isolates from the anuran liver, lung, kidney, spleen, heart and gonad. The isolates were made up of 30 fungal species, 9 of which (48 isolates, 46%) were fungi with known pathogenic potentials, namely: Candida guilliermondii, C. parapsilosis, C. tropicalis, C. glabrata, Geotrichum candidum, Aureobasidium pullulans, Wangiella dermatitidis, Trichosporon cutaneum and Exophiala werneckii. Eleven animals harbored identical fungi in more than one of their internal organs; seven animals had more than one fungal species colonizing a single organ. Our findings indicated probable natural subclinical infections of candidiasis, geotrichosis or phaeohyphomycosis, and also symbiotic presence of non-pathogenic fungi among neotropical anurans.

Distribution of Histoplasma capsulatum in Amazonian wildlife.

In a survey of 296 sylvatic animals captured from virgin forests in the north-eastern and south-western Amazon of Brazil, Histoplasma capsulatum was isolated, via the indirect hamster inoculation method, from the liver and spleen of four common opossums Didelphis marsupialis and two pacas Agouti paca. The infected animals did not show any clinical symptoms or histopathology. The known Amazonian mammalian species with natural histoplasmosis now total five, the previously reported species being the spiny rat Proechimys guyannensis, the two-toed sloth Choloepus didactylus and the nine-banded armadillo Dasypus novemcinctus.

Occurrence and experimental infection of toads (Bufo marinus and B. granulosus) with Mycobacterium chelonei subsp. abscessus.

In a survey of 234 Amazonian toads and frogs, six strains of Mycobacterium chelonei subsp. abscessus were isolated from the liver or spleen of four of 66 Bufo marinus (6.1%) and from the kidney or peritoneal fluid of two of 86 B. granulosus (2.3%). There were no histopathological lesions in the viscera of the infected animals. Experimental infection of 29 captive B. marinus and B. granulosus, by the intraperitoneal route, with a pooled inoculum of M. chelonei subsp. abscessus caused five deaths near the end of a 2-month observation period. M. chelonei subsp. abscessus was isolated from the liver, spleen, kidney, gonad, heart and lung of toads killed at various intervals after inoculation, and intracellular acid-fast bacilli were seen in these organs. Histological evidence of invasion of tissues by mycobacteria became apparent from the 45th day after infection. The susceptibility to infection of B. marinus and B. granulosus suggests that these toads may serve as a fortuitous animal host for M. chelonei subsp. abscessus.

Mycoflora of the human dermal surfaces.

The mycotic flora of the scalp and interdigital areas of the hand and foot of 1296 apparently healthy human inhabitants of three Amazonian communities were surveyed by means of microscopic examination of epidermal scrapings and cultural isolation on Mycosel agar. No macroscopic or microscopic evidence of fungal infection was detected in any of our study subjects. From 133 (10%) individuals, 143 fungi representing 13 genera and 39 species were recovered. Yeasts constituted 85% of the fungi. Seventy-five percent of the isolates were fungi with pathogenic potential: Aureobasidium pullulans, Candida albicans, Candida guilliermondii, Candida parapsilosis, Candida stellatoidea, Candida tropicalis, Exophiala werneckii, Geotrichum candidum, Rhodotorula rubra, Torulopsis glabrata, Trichophyton tonsurans, Trichosporon cutaneum, and Wangiella dermatitidis. The low frequency with which each species was represented resulted in a mosaic distribution of the fungi with respect to human anatomical sites and study areas. The lack of similarity in species composition between the human dermal mycoflora and soil mycoflora in the same study areas supports the conclusion that distinct yeast species occupy different environmental niches.

Ecology of pathogenic yeasts in Amazonian soil.

In an investigation of Amazonian soil as a natural reservoir for pathogenic fungi, 1,949 soil samples collected from diverse geographical and ecological settings of the Brazilian Amazon Basin were analyzed for the presence of non-keratinophilic fungi by the indirect mouse inoculation procedure and for the presence of keratinophilic fungi by the hair bait technique. All soil samples were acidic with low pH values. From 12% of the soil samples, 241 yeast and yeastlike isolates pertaining to six genera and 82 species were recovered, of which 63% were Torulopsis and 26% were Candida species. Nine fungi with known pathogenic potentials were encountered among 43% (104) of the isolates: T. glabrata, C. guilliermondii, C. albicans, C. pseudotropicalis, C. stellatoidea, C. tropicalis, Rhodotorula rubra, and Wangiella dermatitidis. The yeast flora was marked by species diversity, low frequency of each species, random geographical distribution, and an apparent lack of species clustering. The composition and distribution of the yeast flora in soil differed from those of the yeast flora harbored by bats, suggesting that the Amazonian external environment and internal bat organs act as independent natural habitats for yeasts.

Nature and identification of Exophiala werneckii.

The morphological and physiological characteristics of 44 isolates of Exophiala werneckii recovered from human and environmental sources were indistinguishable from 2 isolates that caused tinea nigra. Casein hydrolysis and inability to decompose tyrosine differentiate E. werneckii from Exophiala jeanselmei, Exophiala spinifera, and Wangiella dermatitidis.

Isolation of fungi from bats of the Amazon basin.

A total of 2,886 bats captured in the Amazon Basin of Brazil were processed for the isolation of fungi. From the livers, spleens, and lungs of 155 bats (5.4%), 186 fungal isolates of the genera Candida (123 isolates), Trichosporon (26 isolates), Torulopsis (25 isolates), Kluyveromyces (11 isolates), and Geotrichum (1 isolate) were recovered. Seven known pathogenic species were present: Candida parapsilosis, C. guilliermondii, C. albicans, C. stellatoidea, C. pseudotropicalis, Trichosporon beigelii, and Torulopsis glabrata. Twenty-three culture-positive bats showed identical fungal colonization in multiple organs or mixed colonization in a single organ. The fungal isolation rates for individual bat species varied from 1 fungus per 87 bats to 3 fungi per 13 bats, and the mycoflora diversity for members of an individual fungus-bearing bat species varied from 16 fungi per 40 bats to 7 fungi per 6 bats. Of the 38 fungal species isolated, 36 had not been previously described as in vivo bat isolates. Of the 27 culture-positive bat species, 21 had not been previously described as mammalian hosts for medically or nonmedically important fungi.

Serological analysis and pathogenic potentials of Wangiella dermatitidis isolated from bats.

Five isolates of Wangiella dermatitidis from macroscopically asymptomatic bats were analysed by the agar-gel immunodiffusion tests and the mouse inoculation studies on virulence. No cross-reactivity among the antigens and antisera prepared from the bat and human isolates was observed. The fungus was shown to be neurotropic, of low infectivity and not implicated as a potential opportunistic pathogen. Differences in the antigenic composition and pathogenic potentials between isolates of the same fungus of different origins may reflect adaptation of the fungus in different hosts.

Wangiella dermatitidis isolated from bats in Manaus Brazil.

Wangiella dermatitidis was isolated for the first time from the macroscopically asymptomatic internal organs of 2 Phyllostomus discolor, 1 Molossus molossus, 1 Sturnira lilium and 1 Myotis albescens among bats captured in the region of Manaus, Brazil. The dermatiaceous fungi isolated exhibited polymorphism at 25 and 37 degrees C, showing toruloid hyphae, integrated and terminal phialides without collarettes and yeast-like cells. The fungi did not hydrolyze gelatin, casein or starch. Some ecological aspects of bats in relationship to the epidemiology of phaeohyphomycosis are discussed.

Paracoccidioidin and histoplasmin sensitivity in Coari (state of Amazonas), Brazil.

A skin test survey with paracoccidioidin and histoplasmin was conducted on 495 residents of Coari in the Brazilian state of Amazonas. Positive dermal reactions to paracoccidioidin and histoplasmin were seen, respectively, in 13.9% and 50.1% of the study subjects. Specific reaction to paracoccidioidin was observed in 1.6% of the individuals, and to histoplasmin in 37.8%. Cross-reactivity between the two antigens in persons who reacted positively to both skin tests was not totally reciprocal. There were no significant differences in dermal reactivity to either of the two antigens in either sex, or among different occupational groups. No precipitating antibody to paracoccidioidin or histoplasmin was detected in the sera of the skin test-positive individuals by the immunodiffusion test. Skin test positivity in the general population of Coari reaffirmed the concept of benign, self-limited infection in paracoccidioidomycosis and histoplasmosis. It also identified the equatorial forests of the Upper Amazon Basin as endemic zones of these two mycoses.

Characterization of antigens from type A and B yeast cells of Histoplasma capsulatum.

The antigenic composition of cytoplasmic extract and culture filtrate antigens of type A and B yeast cells of Histoplasma capsulatum grown in a synthetic medium was studied. These preparations from type A and B yeast cells contained varying amounts of protein, carbohydrates, and protein-carbohydrate complexes. The antigenic analysis of these preparations was performed by antigen-antiserum absorption with subsequent immunodiffusion and cross-immunoelectrophoresis with absorption in situ in an intermediate gel. All protein antigens observed in culture filtrate of either type A or B yeast cells were also present in the cytoplasmic extracts of the same type. The cytoplasmic extract of type A and B yeast cells each contained certain characteristic antigens that were not shared by the other type. Rocket immunoelectrophoresis with different molecular weight fractions of the antigenic preparations from both types indicated the polydisperse nature of Histoplasma yeast cell antigens.