The Trojan square

An experimental design, based on orthogonal Latin squares, is described. It is of particular value for variety trials in glasshouses.     

Molecular characterization of the uncultivatable hemotropic bacterium Mycoplasma haemofelis

ABSTRACT: Mycoplasma haemofelis is a pathogenic feline hemoplasma. Despite its importance, little is known about its metabolic pathways or mechanism of pathogenicity due to it being uncultivatable. The recently sequenced M. haemofelis str. Langford 1 genome was analysed and compared to those of other available hemoplasma genomes.Analysis showed that in hemoplasmas genes involved in carbohydrate metabolism are limited to enzymes of the glycolytic pathway, with glucose appearing to be the sole energy source. The majority of the pentose phosphate pathway enzymes that catalyze the de novo synthesis of ribonucleotides were absent, as were cell division protein FtsZ and chaperonins GroEL/ES. Uncharacterized protein paralogs containing putative surface expression motifs, comprised 62% of M. haemofelis and 19% of Mycoplasma suis genome coverage respectively, the majority of which were present in a small number of unstructured islands. Limited mass spectrometry and immunoblot data matched a number of characterized proteins and uncharacterized paralogs, confirming their expression and immunogenicity in vivo.These data have allowed further characterization of these important pathogens, including their limited metabolic capabilities, which may contribute to their uncultivatable status. A number of immunogenic proteins, and a potential mechanism for host immune system evasion, have been identified.     

Sarcomatoid renal cell carcinoma with scant epithelial components in an Angora cat

CASE HISTORY: A 6-year-old, neutered, female Angora cat presented with a history of lethargy and anorexia for 2 months and a clinically palpable and gradually enlarging, solid mass in the abdominal cavity extending from the last costal arch to the pelvic cavity.

CLINICAL FINDINGS: Examination of the cat revealed jaundice, dehydration and hypothermia. Haematological manifestations included lymphopenia and substantial decrease in haematocrit value. Biochemical analysis of the blood revealed hypoglycaemia, three-fold elevated blood urea nitrogen values, increased level of serum aspartate aminotransferase and increased total bilirubin while the creatinine level was normal. Ultrasonographic examination of the abdomen showed a disrupted and large hypoechoic area around the left kidney. The cat was anaesthetised and the left kidney was removed, but the cat died following surgery.

PATHOLOGICAL FINDINGS: On post-mortem examination, the left kidney was markedly enlarged and both the cortical and medullary parenchyma were replaced by confluent, multilobulated, pale tan-white, firm nodular masses protruding above the capsular surface. Metastasis was not observed. Cytological examination revealed a population of spindle-shaped cells of variable size, with abundant coarse chromatin and occasionally prominent nucleoli. Initial sections of the kidney were indicative of undifferentiated sarcoma confirmed by immunohistochemistry revealing vimentin-positive and cytokeratin-negative results in all tumour tissues. Additional sections showed very small amounts of both cytokeratin-positive and vimentin-positive areas.

DIAGNOSIS: Sarcomatoid renal cell carcinoma (SRCC) with scant epithelial components originating from left kidney.

CLINICAL RELEVANCE: Clinical and pathological features were similar to those of human SRCC, even though there was no evidence of metastases. Immunohistochemistry for vimentin and cytokeratin may be useful for definitive diagnosis of renal cell carcinoma with sarcomatoid differentiation, although staining of sections from several different parts of the tumour may be necessary. When a primary renal tumour is presented, SRCC should be considered as this diagnosis may influence treatment protocols and the clinical outcome.     

The effects of low temperatures on the vegetative growth and flowering of the primocane fruiting raspberry ‘Autumn Bliss’

Summary

The effects of low temperatures on subsequent vegetative growth and flowering in the raspberry ‘AutumnBliss’ were investigated. In the first experiment, a number of lifting dates were used to determine the seasonal pattern of dormancy and the effect of natural chilling on plant development. In the second, different durations of artificial chilling(0, 2, 4, 6, 8 and 10 weeks at 0?C) were combined with two lifting dates to investigate the effect of natural and artificial chilling. In these experiments, plants which received little chilling grew slowly and failed to develop beyond short rosettes of leaves but as chilling increased, the rate of vegetative growth increased. This coincided with a decline in the time toflowering. These two responses, however, were distinct. In a third experiment, the effect of vernalization of actively growing canes was tested in an attempt to separate the effects of cold on time to flowering, and on the removalof dormancy. The plants responded significantly to cold treatment and flowering was advanced, indicating a distinct vernalizing effect     

Effects of treadmill exercise on the distribution of blood flow between the hindlimb muscles and abdominal viscera of the laying fowl

1. Blood flow distribution between the abdominal viscera and the leg muscles of regularly-laying Rhode Island Red hens was measured at rest and immediately following treadmill exercise, using the radioactive microsphere technique. 2. Exercise brought about a 150% increase in metabolic rate and this was maintained continuously for 90 min. 3. Although there was a small shift in blood flow distribution towards the hindlimb muscles at the expense of the kidneys and reproductive organs, this was not statistically significant. 4. There was a significant reduction in blood flow to the preovulatory follicles of the ovary during exercise, relative to the rest of the abdominal viscera. 5. It is concluded that exercise of this intensity is insufficient to bring about gross changes in blood flow distribution between the abdominal viscera and the hindlimb muscles. The implications of this finding are discussed in relation to the nutrient and blood flow requirements of the reproductive organs.