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1.
eNeuro ; 9(5)2022.
Article in English | MEDLINE | ID: mdl-36635920

ABSTRACT

The protease caspase-3 is a key mediator of apoptotic programmed cell death. But weak or transient caspase activity can contribute to neuronal differentiation, axonal pathfinding, and synaptic long-term depression. Despite the importance of sublethal, or nonapoptotic, caspase activity in neurodevelopment and neural plasticity, there has been no simple method for mapping and quantifying nonapoptotic caspase activity (NACA) in rodent brains. We therefore generated a transgenic mouse expressing a highly sensitive and specific fluorescent reporter of caspase activity, with peak signal localized to the nucleus. As a proof of concept, we first obtained evidence that NACA influences neurophysiology in an amygdalar circuit. Then focusing on the amygdala, we were able to quantify a sex-specific persistent elevation in caspase activity in females after restraint stress. This simple in vivo caspase activity reporter will facilitate systems-level studies of apoptotic and nonapoptotic phenomena in behavioral and pathologic models.


Subject(s)
Apoptosis , Brain , Male , Female , Mice , Animals , Apoptosis/physiology , Mice, Transgenic , Neuronal Plasticity , Caspase 9
2.
Nat Commun ; 10(1): 5490, 2019 12 02.
Article in English | MEDLINE | ID: mdl-31792216

ABSTRACT

Field cancerization is a premalignant process marked by clones of oncogenic mutations spreading through the epithelium. The timescales of intestinal field cancerization can be variable and the mechanisms driving the rapid spread of oncogenic clones are unknown. Here we use a Cancer rainbow (Crainbow) modelling system for fluorescently barcoding somatic mutations and directly visualizing the clonal expansion and spread of oncogenes. Crainbow shows that mutations of ß-catenin (Ctnnb1) within the intestinal stem cell results in widespread expansion of oncogenes during perinatal development but not in adults. In contrast, mutations that extrinsically disrupt the stem cell microenvironment can spread in adult intestine without delay. We observe the rapid spread of premalignant clones in Crainbow mice expressing oncogenic Rspondin-3 (RSPO3), which occurs by increasing crypt fission and inhibiting crypt fixation. Crainbow modelling provides insight into how somatic mutations rapidly spread and a plausible mechanism for predetermining the intratumor heterogeneity found in colon cancers.


Subject(s)
Colonic Neoplasms/genetics , Disease Models, Animal , Neoplastic Stem Cells/cytology , Animals , Carcinogenesis , Cell Proliferation , Colonic Neoplasms/metabolism , Colonic Neoplasms/physiopathology , Humans , Mice , Mutation , Neoplastic Stem Cells/metabolism , Oncogenes , Thrombospondins/genetics , Thrombospondins/metabolism
3.
Adv Exp Med Biol ; 876: 455-460, 2016.
Article in English | MEDLINE | ID: mdl-26782245

ABSTRACT

It has been proposed that introducing tyrosine residues into human hemoglobin (e.g. ßPhe41Tyr) may be able to reduce the toxicity of the ferryl heme species in extracellular hemoglobin-based oxygen carriers (HBOC) by facilitating long-range electron transfer from endogenous and exogenous antioxidants. Surface-exposed residues lying close to the solvent exposed heme edge may be good candidates for mutations. We therefore studied the properties of the ßLys66Tyr mutation. Hydrogen peroxide (H2O2) was added to generate the ferryl protein. The ferryl state in ßLys66Tyr was more rapidly reduced to ferric (met) by ascorbate than recombinant wild type (rwt) or ßPhe41Tyr. However, ßLys66Tyr suffered more heme and globin damage following H2O2 addition as measured by UV/visible spectroscopy and HPLC analysis. ßLys66Tyr differed notably from the rwt protein in other ways. In the ferrous state the ßLys66Tyr forms oxy, CO, and NO bound heme complexes similar to rwt. However, the kinetics of CO binding to the mutant was faster than rwt, suggesting a more open heme crevice. In the ferric (met) form the typical met Hb acid-alkaline transition (H2O to -OH) appeared absent in the mutant protein. A biphasicity of cyanide binding was also evident. Expression in E. coli of the ßLys66Tyr mutant was lower than the rwt protein, and purification included significant protein heterogeneity. Whilst, ßLys66Tyr and rwt autoxidised (oxy to met) at similar rates, the oxygen p50 for ßLys66Tyr was very low. Therefore, despite the apparent introduction of a new electron transfer pathway in the ßLys66Tyr mutant, the heterogeneity, and susceptibility to oxidative damage argue against this mutant as a suitable starting material for a HBOC.


Subject(s)
Blood Substitutes , Hemoglobins/genetics , Mutation , Electron Spin Resonance Spectroscopy , Humans , Hydrogen-Ion Concentration , Oxygen/metabolism
4.
Aust Vet J ; 92(1-2): 38-40, 2014 Jan.
Article in English | MEDLINE | ID: mdl-24471881

ABSTRACT

BACKGROUND: A nearly 4-year-old neutered male Australian Terrier was referred for a nodular pyogranulomatous mass of the right axilla. It had been poorly responsive to antibiotic therapy. CASE REPORT: Based on filamentous Gram-positive organisms identified in earlier biopsy material, infection by an Actinomyces sp. was suspected and the dog showed clinical improvement on a trial of potentiated sulfonamides. Recurrence 5 months later prompted euthanasia, with Streptomyces cyaneus being cultured and confirmed by genetic sequencing of part of the 16 s ribosomal RNA gene. CONCLUSION: Invasive Streptomyces spp. infections are uncommon in humans and animals, and isolations are sometimes considered to be contaminants, but the demonstration of the organism within the lesion in this instance indicates that the isolation of a Streptomyces sp. from veterinary cases should not always be considered as contamination, because this genus is clearly pathogenic.


Subject(s)
Axilla/microbiology , Dermatitis/veterinary , Dog Diseases/microbiology , Gram-Positive Bacterial Infections/veterinary , Streptomyces/growth & development , Sulfonamides/therapeutic use , Animals , Axilla/pathology , DNA, Bacterial/chemistry , DNA, Bacterial/genetics , Dermatitis/drug therapy , Dermatitis/microbiology , Dermatitis/pathology , Dog Diseases/drug therapy , Dog Diseases/pathology , Dogs , Fatal Outcome , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/microbiology , Gram-Positive Bacterial Infections/pathology , Histocytochemistry/veterinary , Male , Polymerase Chain Reaction/veterinary , RNA, Ribosomal, 16S/chemistry , RNA, Ribosomal, 16S/genetics , Streptomyces/genetics , Sulfonamides/administration & dosage
5.
Disabil Rehabil ; 34(19): 1596-607, 2012.
Article in English | MEDLINE | ID: mdl-22372970

ABSTRACT

PURPOSE: To validate a shortened version of the Participation Scale (P-scale) that will be quicker to use and to describe the factor structure found in the P-scale data in various study samples. METHODS: A large multi-country and multi-cultural database was compiled consisting of 5125 respondents. Item analysis, explanatory factor analysis and confirmatory factor analysis were applied to identify items for deletion and investigate the factor structure of the P-scale. RESULTS: The multi-country database included 11 databases from six different countries. Respondents were affected by a range of health conditions, including leprosy, HIV/AIDS, dermatological conditions and various disabilities. Of the respondents included 57% were male. The P-scale Short (PSS) contains 13 items. A two-factor structure, with factors named "work-related participation" (three items) and "general participation" (10 items), showed the best model fit (Comparative Fit Index = 0.983, Tucker Lewis Index = 0.979, Rooted Mean Square Error of Approximation = 0.061). The Cronbach's alphas were very good for both the whole scale and the subscales, 0.91, 0.83 and 0.90, respectively. Correlation between the two factors was high (r = 0.75) indicating that interpreting the P-scale as measuring an overall factor "participation" is still valid. A very high correlation (r = 0.99) was found between the full P-scale and the PSS. CONCLUSIONS: The findings suggest good validity of the P-scale across a range of languages and cultures. However, field testing needs to confirm the validity of the PSS to measure the level of social participation restrictions across cultures and health conditions.


Subject(s)
Disability Evaluation , Disabled Persons/rehabilitation , Patient Participation/psychology , Psychometrics/instrumentation , Surveys and Questionnaires , Activities of Daily Living , Adult , Aged , Disabled Persons/classification , Disabled Persons/psychology , Factor Analysis, Statistical , Female , Humans , International Classification of Diseases , Male , Middle Aged , Reproducibility of Results , Young Adult
6.
J Eur Acad Dermatol Venereol ; 26(6): 738-45, 2012 Jun.
Article in English | MEDLINE | ID: mdl-21707770

ABSTRACT

BACKGROUND: Large numbers of people are expected to self-manage their skin condition, but limited attention has been given to studies of self-management in psoriasis, neither clearly highlighting the challenge nor seeking to develop interventions to support its effectiveness. OBJECTIVES: 1. To test the feasibility of a new educational intervention to enable people with psoriasis to self-manage more effectively an adequately powered multi-centred trial design through piloting. METHOD: Pilot randomized controlled trial with adults (n = 64) with mild-moderate psoriasis in Primary Care in the United Kingdom. Both groups continued with usual treatment. A theory-based educational intervention was designed. The primary outcome measure was the Dermatology Life Quality Index (DLQI). Secondary measures included the Psoriasis Area and Severity Index (PASI) and qualitative feedback from participants. Assessment of the feasibility of the intervention included recruitment and acceptability to participants. RESULTS: Delivery of the intervention was feasible and positively evaluated. Recruitment strategies and the intervention need minor modification. As a pilot study there was insufficient power to detect significant score changes. Sub group analysis of participants with a PASI or DLQI of >6 indicated a modest reduction in PASI in the intervention group which demonstrates a trend that may indicate that this intervention has potential value for people with moderate psoriasis when combined with qualitative data. CONCLUSION: This study highlights the feasibility of delivering a self-efficacy based educational intervention for people with mild-moderate psoriasis in primary care establishing the numbers and design required for an adequately powered multi-centred trial.


Subject(s)
Nurse-Patient Relations , Patient Education as Topic , Psoriasis/therapy , Self Care , Adult , Aged , Feasibility Studies , Female , Humans , Male , Middle Aged , Pilot Projects , Psoriasis/physiopathology , Quality of Life
7.
J Fish Dis ; 35(1): 19-27, 2012 Jan.
Article in English | MEDLINE | ID: mdl-22103767

ABSTRACT

This is the first pathological description of 'scale drop syndrome' (SDS) in Asian seabass, Lates calcarifer Bloch. Cumulative mortality was estimated at 40-50%. The vasculitis in all major organs including the skin and associated tissue necrosis was distinctive. The dermis overlying scale beds was often necrotic and associated with scale loss. Necrosis of splenic ellipsoids, renal glomeruli and choroid rete glands of eye were further hallmarks of a disease with systemic vascular involvement. The brain was not spared vascular damage, and the resulting multifocal encephalomalacia probably accounts for the spiral swimming behaviour in some affected fish. Other lesions included accentuated hepatic lobulation and gastric gland necrosis. Nuclear chromatin margination and karyolysis in hepatocytes, renal tubular epithelium and gastric and intestinal epithelium suggest specific targeting of cells. Basophilic cytoplasmic inclusions were present in spleen, kidney, liver, heart and choroid rete, but they were not prominent. Using transmission electron microscopy, two morphological forms of virions were observed: single- and double-enveloped hexagonal virions. Based on size and morphology, these virions resemble iridovirus or herpesvirus. The cause of SDS is unknown, but the pathological changes, especially the vasculitis, suggest an infectious aetiology, possibly viral.


Subject(s)
Bass , Fish Diseases/pathology , Animals , Asia , Fish Diseases/mortality , Fish Diseases/virology , Microscopy, Electron, Transmission , Syndrome , Virion/ultrastructure
8.
Vet Parasitol ; 181(2-4): 91-6, 2011 Sep 27.
Article in English | MEDLINE | ID: mdl-21641722

ABSTRACT

An intestinal Eimeria was previously reported as a significant pathogen of Asian seabass (Lates calcarifer) in nurseries in Vietnam. In the present study, both Eimeria and Cryptosporidium were detected by sequence analyses of fragments of the 18S rRNA gene amplified from these Vietnamese L. calcarifer tissues. Based on these analyses, the Eimeria from the Vietnamese L. calcarifer formed clades with the Eimeria detected in L. calcarifer tissues from Australia, but clustered separately from other known Eimeria and Goussia species. The Cryptosporidium detected in L. calcarifer from Vietnam clustered closest with C. parvum and C. hominis. In situ hybridization using DIG-labeled DNA probes generated from 18S PCR products on the Vietnamese L. calcarifer wax block tissues showed that this method could not be used to distinguish between Eimeria and Cryptosporidium, due to the conserved nature of the 18S locus. A previously published study on the morphology of parasite developmental stages and oocysts in the Vietnamese L. calcarifer tissues showed only an intestinal Eimeria infection. The Cryptosporidium could be present at very low levels undetectable by microscopy in intestines, or being ubiquitous, was a possible contaminant from feed or water. While molecular analysis is a very useful tool in the study of disease and identification of aetiological agents, this study reiterates the importance of demonstrating organisms in situ in tissues.


Subject(s)
Bass , Coccidiosis/veterinary , Cryptosporidiosis/veterinary , Cryptosporidium/isolation & purification , Eimeria/isolation & purification , Fish Diseases/parasitology , Animals , Aquaculture , Coccidiosis/epidemiology , Coccidiosis/parasitology , Cryptosporidiosis/epidemiology , Cryptosporidiosis/parasitology , Cryptosporidium/genetics , Eimeria/genetics , Fish Diseases/epidemiology , Gene Expression Regulation , Phylogeny , RNA, Ribosomal, 18S/genetics , Vietnam/epidemiology
9.
Vet Parasitol ; 181(2-4): 106-12, 2011 Sep 27.
Article in English | MEDLINE | ID: mdl-21612869

ABSTRACT

This is the first report of an intestinal Eimeria infection in Asian seabass (Lates calcarifer) at the histopathological and ultrastructural levels. The Eimeria infection was often associated with severe pathology and significant mortality in the absence of other pathogens. This showed that it is an important disease of juvenile L. calcarifer in small scale nurseries in Vietnam. Heavy infection and high prevalence levels of the Eimeria infection are suspected to be linked to the low daily water exchange rates practised in these nurseries. Although systemic iridovirus infection was concurrently observed in some of the fish examined, it was not as consistently present in diseased fish as the Eimeria infection.


Subject(s)
Coccidiosis/veterinary , Fish Diseases/parasitology , Intestinal Diseases, Parasitic/veterinary , Animals , Aquaculture , Bass , Coccidiosis/epidemiology , Coccidiosis/parasitology , Fish Diseases/epidemiology , Intestinal Diseases, Parasitic/epidemiology , Intestinal Diseases, Parasitic/parasitology , Intestinal Mucosa/parasitology , Intestinal Mucosa/ultrastructure , Vietnam/epidemiology
10.
Aust Vet J ; 89(3): 77-81, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21323653

ABSTRACT

A 6-week-old Warmblood colt foal was presented for investigation of multiple haematoma formation in various locations, poor wound healing and abnormal scar formation. Based on the history and clinical presentation of hyperextensible skin with prolonged skin tenting, the foal was diagnosed with cutaneous asthenia and euthanased because of the poor prognosis. Histopathological and electron microscopic findings were inconclusive. This is the first case report of cutaneous asthenia in a Warmblood horse in Australia. Cutaneous asthenia is reviewed with particular reference to hereditary equine regional dermal asthenia and its similarities and differences to the case presented.


Subject(s)
Asthenia/veterinary , Horse Diseases/diagnosis , Animals , Animals, Newborn , Asthenia/diagnosis , Asthenia/genetics , Euthanasia, Animal , Genetic Predisposition to Disease , Horse Diseases/genetics , Horses , Male , Pedigree , Prognosis
11.
Mol Psychiatry ; 16(12): 1169-76, 2011 Dec.
Article in English | MEDLINE | ID: mdl-20856248

ABSTRACT

The brain serotonergic system has an essential role in the physiological functions of the central nervous system and dysregulation of serotonin (5-HT) homeostasis has been implicated in many neuropsychiatric disorders. The tryptophan hydroxylase-2 (TPH2) gene is the rate-limiting enzyme in brain 5-HT synthesis, and thus is an ideal candidate gene for understanding the role of dysregulation of brain serotonergic homeostasis. Here, we characterized a common, but functional single-nucleotide polymorphism (SNP rs1386493) in the TPH2 gene, which decreases efficiency of normal RNA splicing, resulting in a truncated TPH2 protein (TPH2-TR) by alternative splicing. TPH2-TR, which lacks TPH2 enzyme activity, dominant-negatively affects full-length TPH2 function, causing reduced 5-HT production. The predicted mRNA for TPH2-TR is present in postmortem brain of rs1386493 carriers. The rs13864923 variant does not appear to be overrepresented in either global or multiplex depression cohorts. However, in combination with other gene variants linked to 5-HT homeostasis, this variant may exhibit important epistatic influences.


Subject(s)
Alternative Splicing , Depression/genetics , Genetic Predisposition to Disease/genetics , Serotonin/biosynthesis , Tryptophan Hydroxylase/genetics , Animals , Brain Stem/metabolism , Cell Line, Transformed , Female , Genetic Predisposition to Disease/psychology , Genotype , Humans , Male , PC12 Cells , Pedigree , Polymorphism, Single Nucleotide/genetics , Rats
12.
Aust Vet J ; 87(11): 430-7, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19857233

ABSTRACT

OBJECTIVE: To determine if juvenile pearl oysters (Pinctada maxima) infected with Haplosporidium hinei are also infected with another haplosporidian parasite, Minchinia occulta. DESIGN: Archived samples of pearl oysters infected with H. hinei were examined using polymerase chain reaction (PCR) assays and in situ hybridisation (ISH) to analyse and identify haplosporidians. A 144-bp and 220-bp region of Minchinia DNA were targeted by PCR and amplified DNA from formalin-fixed H. hinei-infected pearl oyster samples was sequenced. A 25-bp oligonucleotide probe targeting a variable section of the parasite's small subunit rRNA gene was used in ISH. RESULTS: The results of DNA-based diagnostic assays supported each other. The sequences obtained by PCR were found to be almost identical to M. occulta from rock oysters and the ISH assay demonstrated infection with M. occulta in affected pearl oysters. ISH indicated a prevalence of infection of 26.7% in one of the previous outbreaks. CONCLUSION: Pearl oyster spat are susceptible to infection by a Minchinia parasite, most likely M. occulta, which was recently identified in rock oysters within the pearl-producing zones of Western Australia and is associated with mortalities of up to 80% in this species. The occurrence of haplosporidian co-infections in pearl oysters suggests the immunocompetence of juvenile oysters may be an important factor in preventing infection and therefore preventing mortalities such as those occurring in the recent outbreaks of pearl oyster oedema disease.


Subject(s)
Aquaculture , DNA, Protozoan/analysis , Haplosporida/isolation & purification , Pinctada/parasitology , Animals , Australia , Haplosporida/classification , In Situ Hybridization , Phylogeny , Polymerase Chain Reaction/veterinary , Prevalence , Species Specificity
13.
J Vet Intern Med ; 23(5): 964-9, 2009.
Article in English | MEDLINE | ID: mdl-19678891

ABSTRACT

BACKGROUND: Historically, histiocytic ulcerative (HUC) (or granulomatous) colitis of Boxer dogs was considered an idiopathic immune-mediated disease with a poor prognosis. Recent reports of dramatic responses to enrofloxacin and the discovery of invasive Escherichia coli within the colonic mucosa of affected Boxer dogs support an infectious etiology. HYPOTHESIS: Invasive E. coli is associated with colonic inflammation in Boxer dogs with HUC, and eradication of intramucosal E. coli correlates with clinical and histologic remission. ANIMALS: Seven Boxer dogs with HUC. METHODS: Prospective case series. Colonic biopsies were obtained at initial evaluation in 7 dogs, and in 5 dogs after treatment with enrofloxacin. Biopsies were evaluated by standardized histopathology, and fluorescence in situ hybridization (FISH) with probes to eubacteria and E. coli. RESULTS: Intramucosal E. coli was present in colonic biopsies of 7/7 Boxers with HUC. Clinical response was noted in all dogs within 2 weeks of enrofloxacin (7 + or - 3.06 mg/kg q24 h, for 9.5 + or - 3.98 weeks) and was sustained in 6 dogs (median disease-free interval to date of 47 months, range 17-62). FISH was negative for E. coli in 4/5 dogs after enrofloxacin. E. coli resistant to enrofloxacin were present in the FISH-positive dog that relapsed. CONCLUSIONS AND CLINICAL RELEVANCE: The correlation between clinical remission and the eradication of mucosally invasive E. coli during treatment with enrofloxacin supports the causal involvement of E. coli in the development of HUC in susceptible Boxer dogs. A poor response to enrofloxacin treatment might be due to colonization with enrofloxacin-resistant E. coli.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Colitis, Ulcerative/veterinary , Dog Diseases/microbiology , Escherichia coli Infections/veterinary , Escherichia/growth & development , Fluoroquinolones/therapeutic use , Animals , Biopsy/veterinary , Colitis, Ulcerative/drug therapy , Colitis, Ulcerative/microbiology , Colitis, Ulcerative/pathology , Colon/microbiology , Colon/pathology , Dog Diseases/drug therapy , Dog Diseases/pathology , Dogs , Enrofloxacin , Escherichia coli Infections/drug therapy , Escherichia coli Infections/microbiology , Escherichia coli Infections/pathology , Female , Histocytochemistry/veterinary , In Situ Hybridization, Fluorescence/veterinary , Intestinal Mucosa/drug effects , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Male , Prospective Studies
14.
Parasitology ; 135(11): 1271-80, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18752707

ABSTRACT

A Minchinia sp. (Haplosporidia: Haplosporidiidae) parasite was identified infecting rock oysters and morphologically described by Hine and Thorne (2002) using light microscopy and transmission electron microscopy (TEM). The parasite was associated with up to 80% mortality in the host species and it is suspected that the parasite would be a major impediment to the development of a tropical rock oyster aquaculture industry in northern Western Australia. However, attempts to identify the parasite following the development of a specific probe for Haplosporidium nelsoni were unsuccessful. The SSU region of the parasite's rRNA gene was later characterized in our laboratory and an in situ hybridization assay for the parasite was developed. This study names the parasite as Minchinia occulta n sp. and morphologically describes the parasite using histology, scanning electron microscopy and transmission electron microscopy. The non-spore stages were unusual in that they consisted primarily of uninucleate stages reminiscent of Bonamia spp. The parasite's spores were ovoid to circular shaped and measured 4.5 microm-5.0 microm x 3.5-4.1 microm in size. The nucleus of the sporoplasm measured 1.5-2.3 microm and was centrally located. The spores were covered in a branching network of microtubule-like structures that may degrade as the spore matures.


Subject(s)
Haplosporida/physiology , Haplosporida/pathogenicity , Ostreidae/parasitology , Animals , Aquaculture , Genes, rRNA , Haplosporida/classification , Haplosporida/genetics , In Situ Hybridization , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Molecular Probes , Species Specificity , Spores, Protozoan/ultrastructure , Western Australia
15.
J Small Anim Pract ; 49(7): 349-55, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18638059

ABSTRACT

A five-month-old female Jack Russell terrier was presented for investigation of acute lethargy, anorexia, coughing, respiratory distress and weakness. Examination findings included cyanosis, a grade 3 of 6 systolic heart murmur and prolonged capillary refill time. Radiography and echocardiography revealed severe pulmonary hypertension, cor pulmonale and right-sided heart failure. Indirect measurement of the systolic pulmonary artery pressure estimated pressures over 100 mmHg. Despite treatment the patient died. Post-mortem examination did not identify a congenital cardiovascular anomaly. Histopathology confirmed acute necrotising pulmonary arteritis and immunohistochemistry failed to identify any immune complex or complement deposition.


Subject(s)
Dog Diseases/pathology , Hypertension, Pulmonary/veterinary , Necrosis/veterinary , Vasculitis/veterinary , Acute Disease , Animals , Anti-Anxiety Agents/therapeutic use , Dogs , Fatal Outcome , Female , Furosemide/therapeutic use , Verapamil/therapeutic use
16.
J Clin Pathol ; 61(5): 595-600, 2008 May.
Article in English | MEDLINE | ID: mdl-18326022

ABSTRACT

BACKGROUND: Type 1 leprosy reactions (T1R) are a major inflammatory complication of leprosy affecting 30% of patients with borderline leprosy, but there has been no diagnostic evaluation of the histological diagnosis of this entity. METHODS: In a prospective study based in India, skin biopsies were taken from 99 patients with clinically diagnosed T1R and 52 non-reactional controls. These were assessed histologically by four histopathologists whose assessments were then compared. RESULTS: Reactions were under-diagnosed, with 32-62% of clinically diagnosed reactions being given a histological diagnosis. The pathologists showed good specificities (range 72% to 93%) but much poorer sensitivities (range 42% to 78%). The most commonly reported histological features of TIR were cell maturity, oedema and giant cells. Five key variables were identified that the pathologists used in diagnosing a reaction: intra-granuloma oedema, giant cell size, giant cell numbers, dermal oedema and HLA-DR expression. A predictive model for the diagnosis of T1R was developed using stepwise logistic regression analysis, with clinical diagnosis of reaction as an outcome, and then identification of the key variables that each pathologist used in making the diagnosis of T1R. 34-53% of the variation between pathologists could be accounted for. The four pathologists used a similar diagnostic model and for all of them their estimations of epithelioid cell granuloma oedema, dermal oedema, plasma cells and granuloma fraction were significant variables in the diagnosis of T1R. Each pathologist then added in variables that were specific to themselves. CONCLUSIONS: This study has identified T1R as being under-diagnosed in comparison with clinical assessments. Key variables for diagnosing T1R were established. This comparative masked study highlights the need for such studies in other inflammatory conditions.


Subject(s)
Hypersensitivity, Delayed/pathology , Leprosy/pathology , Skin/pathology , Biopsy , Edema/pathology , Female , Giant Cells/pathology , Granuloma/pathology , Humans , Leprosy/complications , Leprosy, Borderline/complications , Leprosy, Borderline/pathology , Male , Prospective Studies
17.
Parasitology ; 135(4): 521-7, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18248686

ABSTRACT

An infection of pearl oysters, Pinctada maxima, attributed to a Haplosporidium sp. by Hine and Thorne (1998) has been detected on 3 occasions and is considered to represent a serious concern to the pearling industry in Australia. The spore ornamentation of the parasite was determined by scanning electron microscopy and transmission electron microscopy. Spores of the parasite were pleomorphic, or elongated 3.5-4 microm x 2.5-3.0 microm in size. Two filaments were wound around the spore and originated from 2 'knob-like' posterior thickenings. Both filaments passed up one side of the spore together until just below the operculum whereupon each split and passed obliquely under the lip of the opercula lid. Each filament wrapped around the spore 4 times. The posterior thickenings seem to appear late in the development of the spore and were composed of spore wall material. A second set of branching tubular filaments composed of a different material was observed on the spore body although not on mature spores possessing a 'knob-like' posterior thickening. The ornamentation on the spores of the pearl oyster parasite was unique amongst described haplosporidian species where spore ornamentation is known. The parasite is named in this manuscript as Haplosporidium hinei n. sp.


Subject(s)
Haplosporida/ultrastructure , Pinctada/parasitology , Animals , Histocytochemistry , Microscopy, Electron, Scanning , Microscopy, Electron, Transmission , Spores, Protozoan/ultrastructure
18.
Vet Pathol ; 45(1): 95-103, 2008 Jan.
Article in English | MEDLINE | ID: mdl-18192585

ABSTRACT

A progressive wart-like syndrome in both captive and wild populations of the Western barred bandicoot (WBB) is hindering conservation efforts to prevent the extinction of this endangered marsupial. In this study, 42 WBBs exhibiting the papillomatosis and carcinomatosis syndrome were examined. The disease was characterized by multicentric proliferative lesions involving cutaneous and mucosal surfaces, which were seen clinically to increase in size with time. Grossly and histologically the smaller skin lesions resembled papillomas, whereas the larger lesions were most commonly observed to be squamous cell carcinomas. Large amphophilic intranuclear inclusion bodies were observed in hyperplastic conjunctival lesions of 8 WBBs under light microscopy. Conjunctival lesions from 2 WBBs examined using transmission electron microscopy contained a crystalline array of spherical electron-dense particles of 45-nm diameter, within the nucleus of conjunctival epithelial cells, consistent with a papillomavirus or polyomavirus. Conjunctival samples from 3 bandicoots that contained intranuclear inclusion bodies also demonstrated a positive immunohistochemical reaction after indirect immunohistochemistry for papillomavirus structural antigens. Ultrastructural and/or immunohistochemical evidence of an etiologic agent was not identified in the nonconjunctival lesions examined. Here we describe the gross, histopathologic, ultrastructural, and immunohistochemical findings of a papillomatosis and carcinomatosis syndrome recently identified in the WBB.


Subject(s)
Carcinoma/veterinary , Marsupialia , Papilloma/veterinary , Animals , Carcinoma/pathology , Female , Male , Papilloma/pathology
19.
Biochemistry (Mosc) ; 72(10): 1039-46, 2007 Oct.
Article in English | MEDLINE | ID: mdl-18021062

ABSTRACT

Alexander Bach was both revolutionary politician and biochemist. His earliest significant publication, "Tsar-golod" ("The Tsar of Hunger"), introduced Marxist thought to Russian workers. In exile for 30 years, he moved to study the dialectic of the oxidases. When his theory of oxidases as combinations of oxygenases and peroxidases was developed (circa 1900) the enzyme concept was not fully formulated, and the enzyme/substrate distinction not yet made. Peroxides however were then and remain now significant intermediates, when either free or bound, in oxidase catalyses. The aerobic dehydrogenase/peroxidase/catalase coupled systems which were studied slightly later clarified the Bach model and briefly became an oxidase paradigm. Identification of peroxidase as a metalloprotein, a key step in understanding oxidase and peroxidase mechanisms, postdated Bach's major work. Currently we recognize catalytic organic peroxides in flavoprotein oxygenases; such organic peroxides are also involved in lipid oxidation and tryptophan radical decay. But most physiologically important peroxides are now known to be bound to transition metals (either Fe or Cu) and formed both directly and indirectly (from oxygen). The typical stable metalloprotein peroxide product is the ferryl state. When both peroxide oxidizing equivalents are retained the second equivalent is held as a protein or porphyrin radical. True metal peroxide complexes are unstable. But often water molecules mark the spot where the original peroxide decayed. The cytochrome c oxidase Fe-Cu center can react with either peroxide or oxygen to form the intermediate higher oxidation states P and F. In its resting state water molecules and hydroxyl ions can be seen marking the original location of the oxygen or peroxide molecule.


Subject(s)
Oxidation-Reduction , Oxygen/chemistry , Oxygenases/metabolism , Peroxidases/metabolism , Peroxides/chemistry , Water/chemistry , Animals , Biochemistry/history , Biochemistry/methods , Electron Transport Complex IV/chemistry , History, 19th Century , History, 20th Century , Humans , Models, Chemical , Politics
20.
Trans R Soc Trop Med Hyg ; 101(10): 1004-12, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17669450

ABSTRACT

Leprosy type 1 reactions (T1R) are immune-mediated events with inflammation of peripheral nerves and skin. We report the clinical outcomes of a closely monitored open prospective trial in which eight Nepali and 33 Ethiopian patients with T1Rs were treated with an Indian generic formulation of ciclosporin (Cn; 5-7.5 mg/kg/day) for 12 weeks and followed up for 24 weeks after starting treatment. Outcomes were measured using a clinical severity score. Among the Nepalis, 75-100% improved in all acute clinical parameters; 67-100% patients maintained improvement, except for those with acute sensory nerve impairment among whom 67% relapsed after stopping treatment. The skin lesions of all Ethiopians on 5 mg/kg/day of Cn improved and 50-60% had peripheral nerve function improvement. Most Ethiopians needed a higher dose of Cn to improve nerve impairment and neuritis, and 50-78% of them developed worse clinical severity scores when Cn was stopped. Four Ethiopians and two Nepalis developed elevated serum creatinine levels on 7.5 mg/kg/day Cn, and three (9%) Ethiopians developed treatable hypertension. This suggests that Cn monotherapy is an effective treatment for severe T1R with few adverse effects. A dose of 5 mg/kg/day seems efficacious in Nepalis, but a higher dose may be required in Ethiopian patients.


Subject(s)
Cyclosporine/therapeutic use , Immunosuppressive Agents/therapeutic use , Leprosy/drug therapy , Adolescent , Adult , Cyclosporine/pharmacology , Ethiopia/epidemiology , Female , Humans , Immunosuppressive Agents/pharmacology , Leprosy/epidemiology , Leprosy/prevention & control , Male , Middle Aged , Nepal/epidemiology , Prospective Studies , Treatment Outcome
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