Use of restriction fragment length polymorphisms resolved by pulsed-field gel electrophoresis for subspecies identification of mycobacteria in the Mycobacterium avium complex and for isolation of DNA probes.

Mycobacterial strains from the Mycobacterium avium complex were compared with each other and with Mycobacterium phlei isolates by restriction endonuclease digestion of chromosomal DNA with SspI and analysis by pulsed-field gel electrophoresis. Characteristic profiles were observed for known typed strains, and five groups were identified. Primary bovine isolates identified as Mycobacterium paratuberculosis by classical methods were shown to fall into both the M. paratuberculosis- and M. avium-like groups. M. paratuberculosis 18 was in the latter category. Two Mycobacterium intracellulare strains of different Schaefer serotypes had different digestion profiles. In addition, this system was exploited for the preparation of DNA probes by the isolation, digestion, and subcloning of DNA fragments separated by pulsed-field gel electrophoresis. Probe JC12 hybridized only to M. avium complex strains, but not to M. phlei, showing characteristic hybridization profiles for each of the groups previously identified by pulsed-field gel electrophoresis. The approach taken in the study lends itself to the comparative analysis of members of the M. avium complex and to the isolation and characterization of DNA probes with specificity for these mycobacteria.     

Staphylococcus epidermidis protease EcpA can be a deleterious component of the skin microbiome in atopic dermatitis

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Avian adductor profundus muscle: characterization of a pure slow tonic region by histochemical,monoclonal antibody and peptide mapping studies

Summary The fibre type composition of the avian adductor profundus (AP) muscle which is composed of a thick white posterior part (Post. AP) and a thin red anterior part (Ant. AP) was investigated. Using the histochemical ATPase technique, monoclonal antibody analysis of myosin and C-protein isoforms, and electrophoretic and peptide mapping analyses of myosin, we have established that the Post. AP is composed of essentially pure slow tonic fibres similar to those of the anterior latissimus dorsi muscle (ALD). The Ant. AP, on the other hand, is shown to contain a mixture of slow and fast fibres, the latter giving immunocytochemical reactions atypical of the fast fibres. The larger size of the Post. AP in comparison with the ALD muscle should provide significantly more tissue for biochemical studies of tonic fibres than was previously available.     

Fine structure of fiber types in normal human muscle

The fine structure of fiber types in the human vastus lateralis muscle is described. In contrast to the types in other mammals, the two types (red and white) in this muscle seem to differ only in the number and size of mitochondria and not in the amount of sarcoplasmic reticulum or in the structure of myofibrils. The continuity of fiber plasma membrane with the T tubules in the fiber is described. Occasional degenerate foci, which have been found in the normal muscle, are also described.     

The gap effect and express saccades in the auditory modality

Latencies of eye movements to peripheral targets are reduced when there is a short delay (typically 200 ms) between the offset of a central visual fixation point and the target onset. This has been termed the gap effect. In addition, some subjects, usually with practice, exhibit a separate population of very short latency saccades, called express saccades. Both these phenomena have been attributed to disengagement of visual attention when the fixation point is extinguished. A competing theory of the gap effect attributes it to disengagement of oculomotor fixation during the temporal gap. It is known that auditory targets are effective in eliciting saccadic eye movements, and also that covert attention operates in the auditory modality. If the gap effect and express saccades are due to disengagement of spatial attention, both should persist in the auditory modality. However, fixation of gaze is largely under visual control. If the gap effect results from disengagement of fixation, then at least a reduced effect should be seen in the auditory modality. Human subjects performed the gap task and a control task in the dark, using auditory fixation points and saccadic targets, on five successive days. Despite this practice, express saccades were not observed. There was a reliable gap effect, but the reduction in saccadic latency was only 17 ms, compared with 32 ms for the same subjects in the visual modality. This suggests that about half the gap effect is due to disengagement of visual fixation. The remainder was not due to non-specific warning effects and could be attributed to offset of the auditory fixation stimulus. Received: 1 March 1996 / Accepted: 11 July 1997     

How people of African Caribbean or Irish ethnicity cope with long-term health conditions in UK community settings: A systematic review of qualitative,quantitative and mixed method studies

Living with a chronic or mental health condition can be challenging and requires considerable adjustment. As ways of coping are culturally influenced, it is important to understand how minority ethnic populations cope, to inform appropriate services. This review aimed to explore the coping strategies used by UK residents from an African Caribbean or Irish background between 1960 and 2020. A systematic literature search on strategies used to cope with chronic health conditions in both populations living in the United Kingdom identified 26 relevant studies. Data were extracted, quality of papers was appraised and critical interpretive synthesis was applied. Two major foci of the studies were coping strategies and barriers to coping. The main coping strategies were denial/scepticism, self-management, spirituality and religion. Within each population, there was variation in ways of coping. The review highlights the complex role of religion in influencing coping strategies. It demonstrates how personal and minority ethnic populations’ experiences of service use are connected with stigma, fear and mistrust, which also act as barriers to seeking help and to coping. Coping with a chronic or mental health condition in the Irish and African Caribbean populations is under-researched. Stigma, fear and mistrust in services act as key barriers to help-seeking and religion is a prominent coping strategy. However, few detailed examples were given on how it was used to assist individuals when managing a chronic or mental health condition. Also due to a lack of research, firm conclusions cannot be drawn for the Irish population.     

Vascular endothelial growth factor A,secreted in response to transforming growth factor-β1 under hypoxic conditions,induces autocrine effects on migration of prostate cancer cells

Hypoxia and transforming growth factor-β1 (TGF-β1) increase vascular endothelial growth factor A (VEGFA) expression in a number of malignancies. This effect of hypoxia and TGF-β1 might be responsible for tumor progression and metastasis of advanced prostate cancer. In the present study, TGF-β1 was shown to induce VEGFA₁₆₅ secretion from both normal cell lines (HPV7 and RWPE1) and prostate cancer cell lines (DU145 and PC3). Conversely, hypoxia-stimulated VEGFA₁₆₅ secretion was observed only in prostate cancer cell lines. Hypoxia induced TGF-β1 expression in PC3 prostate cancer cells, and the TGF-β type I receptor (ALK5) kinase inhibitor partially blocked hypoxia-mediated VEGFA₁₆₅ secretion. This effect of hypoxia provides a novel mechanism to increase VEGFA expression in prostate cancer cells. Although autocrine signaling of VEGFA has been implicated in prostate cancer progression and metastasis, the associated mechanism is poorly characterized. VEGFA activity is mediated via VEGF receptor (VEGFR) 1 (Flt-1) and 2 (Flk-1/KDR). Whereas VEGFR-1 mRNA was detected in normal prostate epithelial cells, VEGFR-2 mRNA and VEGFR protein were expressed only in PC3 cells. VEGFA₁₆₅ treatment induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2) in PC3 cells but not in HPV7 cells, suggesting that the autocrine function of VEGFA may be uniquely associated with prostate cancer. Activation of VEGFR-2 by VEGFA₁₆₅ was shown to enhance migration of PC3 cells. A similar effect was also observed with endogenous VEGFA induced by TGF-β1 and hypoxia. These findings illustrate that an autocrine loop of VEGFA via VEGFR-2 is critical for the tumorigenic effects of TGF-β1 and hypoxia on metastatic prostate cancers.