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Biomedical subjects

R Malik

Publications and source records attributed to R Malik.

At least 37 records · Page 2Linked to original sources
PubMed2004

PCR studies of feline leprosy cases.

16S rRNA gene sequence analysis provided evidence for two different mycobacterial species, Mycobacterium lepraemurium and a potentially novel species, as causative agents of 'feline leprosy'. Comparison of 16S rRNA gene sequence data obtained for M. lepraemurium and the potentially novel species indicated 12 nucleotide differences over a 446 bp region encompassing the V2 and V3 hypervariable regions. From available 16S rRNA gene sequence data, M. lepraemurium shared greatest nucleotide identity with M. avium subsp paratuberculosis and M. avium. The novel species had a long helix 18 in the V3 region and shared greatest nucleotide identity with M. leprae, M. haemophilum and M. malmoense. The novel species had an additional 'A' nucleotide at position 105 of the aligned 16S rRNA gene sequence, the only other mycobacterial database sequence having this same extra nucleotide being M. leprae. This nucleotide variation was exploited to develop specific PCR assays for the two species. These were found to be effective and specific when tested against a panel of mycobacteria including species found in feline leprosy lesions and closely related mycobacteria and also when applied directly to formalin-fixed, paraffin-embedded tissues from feline leprosy cases.

Animals↗
PubMed2004

Lower respiratory tract infections in cats: 21 cases (1995-2000).

Twenty-one lower respiratory tract infections diagnosed in cats at University of Sydney Veterinary Centre between 1995 and 2000 were identified retrospectively. Patient records were analysed to determine historical, clinical, clinicopathologic and radiographic features of lower respiratory tract infections. Response to therapy was also assessed. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Mycobacterium thermoresistible, Cryptococcus neoformans, Toxoplasma gondii, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study provides a detailed retrospective analysis of infectious lower respiratory tract disease in this population of cats.

Animals↗
PubMed2004

A retrospective analysis of feline bronchoalveolar lavage cytology and microbiology (1995-2000).

A retrospective study of 88 bronchoalveolar lavage specimens from 80 cats presenting to the University of Sydney Veterinary Centre between 1995 and 2000 was performed. Bronchoalveolar lavage cytology and microbiology in conjunction with other diagnostic aids and patient records were used to classify cases as lower respiratory tract infections (LTRIs), LRTI revisits, feline bronchial disease, cardiac disease, neoplastic disease and multisystemic disease. Cases for which a definitive diagnosis could not be made were classified as inconclusive. Infectious agents identified were Mycoplasma spp., Pasteurella spp., Bordetella bronchiseptica, Salmonella typhimurium, Pseudomonas sp., Cryptococcus neoformans, Aelurostrongylus abstrusus and Eucoleus aerophilus. The study highlights the importance of bronchoalveolar lavage cytology and microbiology in the evaluation of feline lower respiratory tract disease.

Animals↗
PubMed2004

Diagnosis of feline haemoplasma infection in Australian cats using a real-time PCR assay.

A total of 147 cats from the Sydney area of Australia that had blood samples submitted to veterinary laboratories were tested using a real-time polymerase chain reaction (PCR) assay able to detect and distinguish the two feline haemoplasma species. This sample number included two cats diagnosed with feline haemoplasma infection by routine blood smear examination. Statistical analysis was performed to evaluate associations between haemoplasma infection, age, sex, breed, haematocrit (HCT) values and anaemia status. One hundred and six cats (72.1%) were negative. Thirty-four cats (23.1%) were positive for 'Candidatus M. haemominutum', six cats (4.1%) were positive for M. haemofelis and one cat (0.7%) was positive for both species. Older, male, non-pedigree cats, with lower HCT values were more likely to be infected with 'Candidatus M. haemominutum'. Significant inverse correlation was found between the amount of M. haemofelis DNA present in the blood and the HCT value. This report documents the existence of, and prevalence of, both haemoplasma species in a sample of cats in Australia and is the first to use quantitative real-time PCR in a prevalence study for haemoplasma infection.

Age Factors↗
PubMed2004

The use of real-time PCR in the diagnosis and monitoring of Mycoplasma haemofelis copy number in a naturally infected cat.

A 5-year-old male neutered cat was diagnosed with severe anaemia due to acute Mycoplasma haemofelis infection. Inflammatory respiratory disease was present concurrently. The cat was treated successfully using a fresh transfusion of whole blood and a 6 week course of doxycycline. The patient made a rapid recovery although the allergic airway disease subsequently required specific therapy consisting of inhaled fluticasone and salbutamol. Real-time quantitative PCR assays confirmed the presence of M. haemofelis DNA copies in the blood at presentation. Repeat PCR assays showed a reduction in copy number during treatment and negative PCR results were obtained both 91 and 425 days after presentation. The report describes, for the first time, the use of real-time PCR in the diagnosis and monitoring of natural M. haemofelis copy number, as well as the induction of long-term negative PCR status.

Anemia↗
PubMed2004

Twenty-five cases of feline bronchial disease (1995-2000).

Twenty-five cases of feline bronchial disease were identified retrospectively. The criteria for inclusion were consistent clinical signs or histopathology and no other identifiable aetiology. Patient records were analysed to determine historical, clinical, clinicopathologic and radiographic features. The main presenting complaints were coughing and dyspnoea. The most common physical finding was dyspnoea. The majority of radiographs had a bronchial pattern either as the sole change or as a component of a mixed pattern. Bronchoalveolar lavage cytology was neutrophilic or eosinophilic in the majority of cats. There was no association between age, breed, sex, clinical signs, bronchoalveolar lavage cytology or radiographic severity and disease severity.

Animals↗
PubMed2004

Retrospective study of feline and canine cryptococcosis in Australia from 1981 to 2001: 195 cases.

A retrospective study of 155 cats and 40 dogs diagnosed with cryptococcosis between 1981 and 2001 was undertaken. Age, sex, breed, clinical findings, feline immunodeficiency virus and feline leukaemia virus status (in cats), species of Cryptococcus causing disease and region of domicile were recorded. Associations between variables were tested. Male and female cats were affected equally. Age ranged from 1 to 16 years, with a preponderance of cats aged between 2 and 3 years. Siamese, Himalayan and Ragdoll breeds were over-represented. Rural cats were more frequently infected with Cryptococcus gattii. Retroviral infection was not identified as a predisposing condition and was not correlated with either species of Cryptococcus or physical findings. Most cats had signs of nasal cavity infection, which was typically localised for a substantial period before invasion of adjacent structures or dissemination. Male and female dogs were affected equally. A marked preponderance of young, large breed dogs was noted. Border Collies, Boxers, Dalmatians, Dobermann Pinschers, Great Danes and German Shepherds were over-represented. Cryptococcus species involved was not affected by place of domicile. Although nasal cavity involvement was important, the canine cohort had a greater propensity to develop secondary central nervous system involvement and disseminated disease than feline cases. There were no clinical findings in either cats or dogs which could be reliably used to distinguish disease caused by Cryptococcus neoformans variety grubii from disease caused by Cryptococcus gattii. Both Cryptococcus species appear to be primary pathogens of cats and dogs, with the upper respiratory tract presumed to be the predominant primary site of inoculation in most but not all cases.

Animals↗
PubMed2004

Infections of the subcutis and skin of dogs caused by rapidly growing mycobacteria.

Nine dogs with panniculitis due to rapidly growing mycobacteria (RGM) were examined over 17 years. Dogs were two to 15 years; five were male, four were female. All were obese or in good condition. Antecedent injury, typically a dog bite or vehicular trauma, could be identified in some patients, while one bitch had hyperadrenocorticism. Infections involved different locations, although the cervicothoracic region, dorsum or flank were most often affected. Patients were systemically well, apart from one dog with pyrexia and two with pain or lameness. Cytology demonstrated pyogranulomatous inflammation, but in only one case was it possible to see acid-fast bacilli (AFB) in smears. Histology demonstrated chronic active pyogranulomatous panniculitis and dermatitis; AFB could be detected in only four specimens. Culture of aspirates or resected tissues demonstrated RGM in all cases, comprising six Mycobacterium smegmatis group and three Mycobacterium fortuitum group isolates. Resection of infected tissues, perioperative injectable antimicrobials and long courses of oral antimicrobials chosen according to susceptibility data generally effected a cure, although some cases recurred.

Animals↗
PubMed2004

Successful treatment of cryptococcal pneumonia in a pony mare.

A 20-year-old Welsh Mountain Pony (212 kg) mare was initially presented for a chronic cough, fever, weight loss and low grade abdominal pain. She later developed dyspnoea, tachypnoea and exercise intolerance. The presence of multiple masses (up to 17 cm diameter) in the pulmonary parenchyma was established using lateral thoracic radiography and transthoracic ultrasonography. Encapsulated, budding yeasts were observed in smears made from transtracheal washings and needle aspirates of the pulmonary lesions. Cryptococcus gattii (synonym: Cryptococcus neoformans variety gattii; Cryptococcus bacillisporus) was cultured from the transtracheal washings and aspirates of the lung masses. The pony was successfully treated using daily intravenous infusions of amphotericin B (typically 0.5 mg/kg in 1 L 5% dextrose in water over 1 h, following premedication with 50 mg flunixin intravenously) over a 1 month period, until a cumulative dose of 3 g had been administered. Treatment was considered to be successful on the basis of progressive improvement in clinical signs, reduction in the size of pulmonary cryptococcomas, 48 kg weight gain and a reduction in the cryptococcal antigen titre from 4096 to 256, 1 year after cessation of treatment.

Amphotericin B↗
PubMed2003

1-[2-(4-nitrophenoxy)acetyl]pyrrolidin-2-one: an antiamnesic agent.

The title compound, C(12)H(12)N(2)O(5), is a potential antiamnesic agent. The pyrrolidinone ring has an envelope conformation, and the central moiety is almost coplanar with the planes of the phenyl and pyrrolidinone rings. In the crystal structure, weak intermolecular C--H...O interactions link the molecules into a complex network that can be described by R(2)(2)(X) rings (X = 16, 20 and 26) and a C(12) chain.

Amnesia↗
PubMed2003

2-(2-Naphthyloxy)acetate derivatives. I. A new class of antiamnesic agents.

The title compounds 1-(2-naphthyloxymethylcarbonyl)piperidine, C(17)H(19)NO(2), (I), and 3-methyl-1-(2-naphthyloxymethylcarbonyl)piperidine, C(18)H(21)NO(2), (II), are potential antiamnesics. In (II), the methyl-substituted piperidine ring is disordered over two conformations. The piperidine ring has a chair conformation in both compounds. In (I), the molecules are linked by weak intermolecular C-H.O interactions to give networks represented by C(4), C(6) and R(4)(4)(18) graph-set motifs, while in (II), weak intermolecular C-H.O interactions generate R(1)(2)(5), C(4) and C(7) graph-set motifs. The dihedral angle between the naphthalene moiety and the piperidine ring is 33.83 (7) degrees in (I), while it is 31.78 (11) and 19.38 (19) degrees for the major and minor conformations, respectively, in (II).

Journal Article↗
PubMed2003

Diaphragmatic hernia in a cat mimicking a pulmonary mass.

A seven-year-old castrated British shorthair cross cat was presented for coughing of five-weeks duration. Thoracic radiographs and an unguided bronchoalveolar lavage showed changes consistent with inflammatory airway disease. In addition, a soft tissue density was evident in the thoracic films between the heart and the diaphragm. Exploratory thoracotomy demonstrated a diaphragmatic hernia, probably congenital in origin, with incarceration of a portion of the hepatic parenchyma. The herniated portion of liver was resected surgically and the defect in the diaphragm closed. The cat was given a 10-day course of doxycycline post-operatively and the cough did not recur subsequently. In retrospect, the hernia was potentially an incidental problem, the cat's coughing being attributable to inflammatory airway disease.

Animals↗
PubMed2003

Disseminated melioidosis in two cats.

Melioidosis was diagnosed in two cats at necropsy. The first cat presented with jaundice and anaemia but died of overwhelming sepsis soon after admission, despite blood transfusion and other supportive measures. The second cat died several days after developing neurological signs; an infected digital wound may have been the primary focus of infection in this patient. The cats had presumably acquired the infection in Malaysia and northern Australia, respectively, and in both cases disease may have represented reactivation of a latent infection brought on by the stress of relocation. The epidemiology, clinical presentation, diagnosis and treatment of melioidosis are discussed from a feline perspective.

Animals↗
PubMed2003

Using human reliability analysis to detect surgical error in endoscopic DCR surgery.

The aim of this study was to describe the nature of active skill-based errors occurring in endoscopic dacrocystorhinostomy (DCR) surgery. A human reliability analysis methodology was used to assess surgical error from observational capture data. Twelve endoscopic DCR operations performed by three different surgical trainees were video recorded. The steps (subtasks) of each operation were carefully analysed and common errors were documented. Specific errors that resulted in trauma to the nasal mucosa were noted. Execution errors were common, with errors of grasping being most frequent (67% of all execution errors). Most of these involved the Blakesley forceps. In total, there were 69 mucosal trauma hits. Inserting instruments into or withdrawing them from the nasal cavity with too much force or speed caused more than half of these. Incising with too much force resulting in 'overshoot' caused 34% of mucosal trauma. Trainee ENT surgeons should take particular care when inserting or withdrawing instruments from the nasal cavity and also when performing lacrimal sac or nasal mucosa incisions. Performance of these tasks with too much force was identified as a common and potentially avoidable cause of mucosal trauma. Further research is needed into the design and use of endoscopic sinus surgery instruments with the aim of avoiding the errors that were encountered.

Dacryocystorhinostomy↗
PubMed2003

Cryptococcus neoformans var. gattii in the koala (Phascolarctos cinereus): a review of 43 cases of cryptococcosis.

Details of 11 previously reported cases and 32 new cases of cryptococcosis in captive and wild koalas were analysed. Cryptococcus neoformans var. gattii accounted for all 29 cases in which varietal status was determined. No age or sex predisposition was observed. The respiratory tract was the primary focus of disease in 77% of cases. Although the lower respiratory tract was affected most commonly (60% of cases), 30% of cases had upper respiratory tract lesions and 14% had both. Dissemination was common, especially to the central nervous system (37% cases). Local extension to surrounding tissues was a feature of upper respiratory tract disease. Other tissues showing cryptococcal invasion included lymph nodes (19%), gastrointestinal tract (12%), kidneys (12%), spleen (9%) and skin (7%). Only three cases (7%) had no respiratory tract or central nervous system involvement, two cases of primary skin inoculation and one case of primary lymphadenopathy. Late presentation was a likely factor in the high proportion of cases with disseminated disease (40%). The proportion of koala cases with involvement of the central nervous system, lower respiratory tract and skin, parallels what has been reported for immunocompetent people. Cryptococcosis in the koala appears to be an excellent naturally occurring model for examination of the cryptococcal host-parasite relationship in all species.

Animals↗