Vibration elicited vasoconstrictor reflex in Raynaud''s phenomena.

The fingers of seven women with primary Raynaud's phenomenon (PRP), 10 female controls, seven men with vibration induced white finger (VWF), and eight male controls were exposed to vibration and the relative change in finger capillary blood flow was measured by an atraumatic 133xenon washout technique without and during proximal nervous blockade. All four groups showed a vasoconstriction to vibration (p less than or equal to 0.02) which was abolished by proximal nervous blockade. Women with PRP had an augmented response to vibration (p less than 0.01) and men with VWF had a normal response (p greater than 0.10) when compared with that of their respective sex matched controls. The results show the existence of a vibration elicited central sympathetic vasoconstrictor reflex in the normal finger and in fingers affected by PRP and VWF. The results indicate a hyperreactivity of the central sympathetic nervous system in PRP and VWF and a dysfunction of the peripheral sensory nerve fibres in subjects with VWF. The described vibration test may be of guidance in the differentiation of PRP from VWF.     

Changing smoking, drinking, and eating behaviour among pregnant women in Denmark. Evaluation of a health campaign in a local region

Health behaviour during pregnancy was examined before and after a comprehensive health campaign targeted at pregnant women in Odense, Denmark. Furthermore, lifestyle habits were compared before and during the campaign with similar habits in Aalborg, Denmark. All 13,815 pregnant women (equal numbers from each city) were enrolled in the study, and 11,980 gave information on eating, drinking, and smoking habits during pregnancy. Data collection in both cities took place from April 1984 to April 1987. The campaign, which was entitled "Healthy Habits for Two", ran from April 1985 to April 1987 in the city of Odense only. No significant change in health behaviour in the Odense area was noted after the start of the campaign.     

Increased NADPH-diaphorase activity in canine myxomatous mitral valve leaflets

Comparable pathological changes in the mitral valve have been described in dogs, pigs and human patients with myxomatous mitral valve disease (MMVD), i.e., primary mitral valve prolapse. The progressive myxomatous changes are probably a response to repeated impact on the leaflets, and endothelial stress or damage probably plays a central role in the pathogenesis. Little, however, is known about the vasoactive substances that mediate the subendothelial changes. The aim of this study was to investigate the expression of nitric oxide synthase (NOS) in canine mitral valve leaflets and to relate the findings to MMVD changes. The mitral valve was taken post mortem from 12 dogs (six males and six females) and a whole valve NADPH (the reduced form of nicotinamide-adenine dinucleotide phosphate) diaphorase (NADPH-d) reaction was performed. Macroscopical (semiquantitative) and microscopical (computer image analysis) evaluations of the staining due to NADPH-d activity were performed at four specific areas of the valve and related to microscopical signs of MMVD and gross signs of thickening or prolapse, or both. Macroscopically, the NADPH-d colour grade was correlated with the degree of MMVD (P=0.01). In addition, endothelial NADPH-d staining intensity was correlated with macroscopical signs of disease (P=0.004) as well as with collagen degeneration (P=0.008) and deposition of mucopolysaccharides (P=0.02). Age, gender and specific area of the valve did not seem to influence the NADPH-d activity. In conclusion, increased NADPH-d activity, suggesting increased NOS expression, was found in areas of the mitral valve with myxomatous changes. This indicates that nitric oxide (NO) may play a role in the pathogenesis of MMVD in dogs.     

Pasteurella multocida in scavenging family chickens and ducks: carrier status, age susceptibility and transmission between species.

Pasteurella multocida causes fowl cholera, a highly contagious and severe disease in chickens and water fowls. The disease is not well described in less intensive production systems, including scavenging family poultry production in developing countries. P. multocida was isolated from 25.9% of healthy-looking ducks and 6.2% of chickens from free-range family poultry farms and at slaughter slabs at market. On experimental infection with 1.2 to 2.0 x 10(8) organisms of the P. multocida type strain (NCTC 10322(T)), 12-week-old chickens expressed fowl cholera clinical signs significantly more times (372 signs) than those of 4-week-old, 8-week-old and 16-week-old chickens (173, 272 and 187 signs) and more signs were severe. In family ducks the 8-week-old birds expressed clinical signs significantly more times (188 signs) than those of the other age groups (117, 80, and 83 signs, respectively) and severe signs were more frequent. P. multocida transmitted from seeder birds (n=12) to sentinel birds (n=30), which developed clinical signs, and in some cases lesions of fowl cholera allowed bacterial re-isolation, whether infected ducks served as seeders for chickens or chickens served as seeder for ducks. This study has documented the occurrence of P. multocida among healthy-appearing family poultry in a tropical setting, and demonstrated that age susceptibility is highest in 12-week-old family chickens and 8-week-old family ducks when challenged with a low-virulent strain of P. multocida. It has further demonstrated that cross-transmission of fowl cholera may happen between family ducks and chickens, and vice versa.     

Decreased infectivity despite unaltered C3 binding by a DeltahbhA mutant of Mycobacterium tuberculosis

HbhA of Mycobacterium tuberculosis is a multifunctional binding protein, binding to both sulfated sugars such as heparin and to human complement component C3. HbhA may therefore interact with host molecules and/or host cells during M. tuberculosis infection and play a role in the pathogenesis of this bacterium. The purpose of this study was to use allelic exchange to create an M. tuberculosis strain deficient in expression of HbhA to determine whether this protein's C3-binding activity plays a role in the pathogenesis of M. tuberculosis. An in-frame, 576-bp unmarked deletion in the hbhA gene was created using sacB as a counterselectable marker. Southern blotting and PCR analyses confirmed deletion of hbhA in the DeltahbhA mutant. The DeltahbhA mutant strain grew at a rate similar to that of the parent in broth culture and in J774.A1 murine macrophage-like cells but was deficient in growth compared to the parent strain in the lungs, liver, and spleen of infected mice. In addition, the DeltahbhA mutation did not reduce binding of M. tuberculosis to human C3 or to J774.A1 cells in the presence or absence of serum, suggesting that in the absence of HbhA, other molecules serve as C3-binding molecules on the M. tuberculosis surface. Taken together, these data indicate that HbhA is important in the infectivity of M. tuberculosis, but its ability to bind C3 is not required for mycobacterial adherence to macrophage-like cells. Using the DeltahbhA mutant strain, a second M. tuberculosis C3-binding protein similar in size to HbhA was identified as HupB, but the role of HupB as a C3-binding protein in intact organisms remains to be determined.     

Bacterial persistence and immunity in goats vaccinated with a purE deletion mutant or the parental 16M strain of Brucella melitensis.

To evaluate host responses, young goats were inoculated subcutaneously with a genetic deletion mutant (deltapurE201) of Brucella melitensis (n = 6), its virulent parental strain 16M (n = 6), or saline (n = 6). No clinical evidence of brucellosis was seen in any goat. Serum antibody titers peaked at postinoculation day (PID) 14. Bacteria in lymph nodes that drained sites of vaccination reached peak numbers of >10(6) CFU/g in both infected groups at PID 7 and progressively declined to PID 84. At necropsy, bacteria were present in mammary lymph nodes or spleen of 33% of goats given virulent 16M but in none of goats given the purE mutant. Lymphadenitis, most severe in goats given 16M, involved depletion of lymphocytes and germinal centers, proliferation of lymphoblasts, and vasculitis. By PID 28, lymph node architecture was restored; there was marked germinal center formation and medullary plasmacytosis. Brucellar antigens, detected with immunoperoxidase techniques, were prominent in capsular granulomas but not in lymph node cortices. Ultrastructurally, bacteria were found in macrophages (>97%) and small lymphocytes (<3%) but not in large lymphocytes. Bacteria were intact in small lymphocytes but in macrophages were in various stages of degradation. The deltapurE phenotype of deltapurE201 was preserved during infection of goat lymph nodes. Unlike Salmonella spp. purE mutants, strain deltapurE201 may be a candidate for efficacy testing; it produced immune responses, was cleared from visceral tissues, and produced less severe pathologic changes than its wild-type parent.     

Bovine NK cells can produce gamma interferon in response to the secreted mycobacterial proteins ESAT-6 and MPP14 but not in response to MPB70

Bovine NK cells have recently been characterized and the present study describes the interaction between NK cells, antigen-presenting cells, and secreted mycobacterial proteins. Gamma interferon (IFN-gamma) production by NK cells was seen in approximately 30% of noninfected calves in response to the Mycobacterium tuberculosis complex-specific protein ESAT-6, MPP14 from Mycobacterium avium subsp. paratuberculosis, and purified protein derivative (PPD) from M. tuberculosis. In contrast, no response was induced by MPB70, which is another M. tuberculosis complex-specific secreted antigen. The production of IFN-gamma by NK cells in whole blood in response to ESAT-6 and MPP14 was demonstrated using intracellular staining together with surface labeling for the NK cell-specific receptor, NKp46, or CD3. Furthermore, the depletion of NK cells from peripheral blood mononuclear cells completely abolished the IFN-gamma production. The response was mediated through stimulation of adherent cells and was largely independent of contact between adherent cells and the NK cells. Neutralization of interleukin-12 only partly inhibited IFN-gamma production, showing that other cytokines were also involved. The demonstration of NK cell-mediated IFN-gamma production in young cattle provides an explanation for the nonspecific IFN-gamma response frequently encountered in young cattle when using the IFN-gamma test in diagnosis of mycobacterial infections.