Distribution of fusimotor axons to intrafusal muscle fibres in cat tenuissimus spindles as determined by the glycogen-depletion method.

1. The distribution of fusimotor axons to bag1, bag2 and chain muscle fibres in cat tenuissimus spindles has been studied using a modification of the glycogen-depletion technique of Edstrrom & Kugelberg (1968). Single fusimotor axons were stimulated intermittently at 40-100/sec for long periods (30-90 sec) during blood occlusion. Portions of muscle containing the activated spindles were quick-frozen, fixed in absolute ethanol during freeze-substitution, and then embedded in paraffin wax. Serial transverse sections were stained for glycogen using the periodic acid-Schiff method, and examined for depletion. 2. Dynamic gamma axons (i.e. those that increase the dynamic index of primary-ending responses to ramp stretches of large amplitude) depleted bag1 fibres almost exclusively. 3. Static gamma axons (i.e. those that reduce or abolish the dynamic index) depleted both bag and chain fibres. Bag1 and bag2 fibres were depleted about equally. 4. A single static gamma axon may activate both bag and chain fibres in one spindle (the most common pattern), chain fibres only in another, and bag fibres only in a third spindle. 5. Static gamma axons with conduction velocities less than 25 m/sec also had a non-selective distribution, but no depletion was observed in bag2 fibres. 6. The zones of depletion produced by dynamic gamma axons were distributed more or less equally in the intra- and extracapsular parts of spindle poles, whereas those produced by static gamma axons were mainly intracapsular. 7. The results are compared with the glycogen-depletion studies of Brown & Butler (1973, 1975) and our own study of the distribution of static gamma axons to spindles in which all other motor axons had degenerated (Barker, Emonet-Dénand, Laporte, Proske & Stacey, 1973). The implications of the finding that both static gamma and dynamic gamma axons activate bag1 fibres are discussed.     

Quantification of the morphological features of a full microvascular network

Investigations into the changes that occur in microvasculature following the surgical procedure called delay have brought about the need for a computer system capable of quantifying the morphological features of a full microvascular network in terms of average vessel length, diameter, and tortuosity. Both the formulaic conventions that have been developed to measure these quantities as well as their implementation in the form of a HP-9000/UNIX based computer software system that we developed specifically for this purpose are discussed. Reliability studies performed using the final system to measure the microcirculatory network of a mouse latissmus dorsi muscle (LDM) showed 95% confidence intervals within 5% of means and coefficients of variability within 7% of means for all quantities measured in large (150–300 μm), medium (50–150 μm), and small (<50 μm) diameter vessels. These variations were significantly smaller than the changes that were observed in a preliminary study comparing these microvascular network parameters before and after delay in the hairless mouse LDM, showing the proposed quantification methods to be well suited to the study of the microvascular changes following delay. It is hoped that the formulaic conventions, implementation process and reliability data will provide a useful comparison for other researchers interested in measuring similar features of microcirculatory networks.     

PCR-based diagnosis of acute and chronic cutaneous leishmaniasis caused by Leishmania (Viannia)

We evaluated PCR methods for diagnosis of acute and chronic cutaneous leishmaniasis (CL) in an area of Colombia where Leishmania (Viannia) is endemic. The PCR method specifically amplified whole linearized minicircle kinetoplast DNA (kDNA) of the Leishmania subgenus Viannia from biopsy lysates. PCR products were detected in agarose gels. For 255 acute cases, this PCR method had greater sensitivity (75.7%) than each conventional method, i.e., microscopic examination of Giemsa-stained lesion scraping (46.7%), biopsy culture (55.3%), aspirate culture (46.3%), and the conventional methods combined (70.2%). Among 44 cases of chronic CL, amplification of biopsy DNA was more sensitive (45.5%) than the individual (4.5 to 27.7%) and combined (27.3%) conventional methods. The detection of kDNA in biopsies from chronic lesions was enhanced by a chemiluminescent dot blot hybridization, which produced a sensitivity of 65.8% when alone and 90.9% when in combination with DNA extraction of biopsy lysates (P < 0.001). Three biopsies from 84 skin lesions of other etiologies were falsely positive by PCR (specificity, 96.4%). PCR detected kDNA more frequently in biopsies (detection level, 83.9%) than in aspirates (74.7%) from 103 cases of acute CL. Among aspirates from 53 chronic cases of CL, the alternative methods, DNA extraction and hybridization, increased sensitivity from 41.5 to 56.6% (P > 0.05). This enhanced PCR method in chronic biopsies was so much more sensitive than conventional methods that it should be considered the preferred diagnostic method for chronic CL. These findings support the appropriate incorporation of PCR into diagnostic strategies for cutaneous leishmaniasis.     

How clients with religious or spiritual beliefs experience psychological help‐seeking and therapy: A qualitative study

This qualitative study explored the process of help‐seeking and therapy among clients with religious or spiritual beliefs. Ten clients who were currently in, or had recently finished, therapy were interviewed. Participants reported using their religious or spiritual beliefs to cope with their psychological problems before and during therapy. Prior to therapy, they were worried that secular‐based help might weaken their faith. However, the experience of having psychological distress and the process of receiving therapy were both perceived as strengthening to faith and ultimately part of a spiritual journey. Contrary to expectations, a match between the spirituality or religious affiliation of the therapist and client was not considered important. This implies that the ‘religiosity gap’ between secular therapists and clients with religious/spiritual beliefs is bridgeable. Copyright © 2007 John Wiley & Sons, Ltd.     

Characterization of the receptor for IgM present on human B lymphocytes.

The presence of a receptor for the Fc of IgM (muFcR) was demonstrated on the pathological B cells of all of sixteen patients with hairy-cell leukaemia and most, but not all, of twenty-four cases of chronic lymphocytic leukaemia, by a rosette method employing ox erythrocytes sensitized with purified IgM (EAm). This muFcR was also demonstrated on a small population of normal human mononuclear cells from peripheral blood. Pathological B cells with this receptor (Bm) simultaneously expressed a different and distinct receptor for the Fc of IgG, and were detectable without preincubation in medium containing foetal calf serum (FCS). The muFcR on B cells was blocked by Fc5mu and IgM, but not by F(ab')2mu fragments, or by IgG, whether monomeric or aggregated. Monomeric IgM and IgM bound to its antigen blocked much more effectively than pentameric IgM. B cells also possessed surface immunoglobulin and the Ia-like P29, 34 antigen, and an antiserum to this antigen blocked the muFcR. The muFcR on B cells differs in a number of ways from the muFcR reported on T cells, and these differential characteristics are discussed in some detail. The muFcR was rapidly shed and resynthesized when washed Bm cells were maintained in medium not containing FCS and the general importance of this phenomenon in any study of muFcR is considered. It is suggested that Bm cells are memory cells and that the muFcR plays a part in the immune response.     

Bacterial flora of the appendix fossa in appendicitis and postoperative wound infection

Bacteria were isolated from 153 (47.5%) swabs of the appendix fossa in 322 patients undergoing appendicectomy. The commonest organism was Bacteroides species found in 78% of specimens. Other Gram-negative bacilli such as Klebsiella, or Enterobacter, and Esch. coli were present in 29 and 27% respectively. Gram-positive cocci were less frequently isolated.A positive culture was obtained more commonly in perforated appendicitis (79%) than where chronic fibrosis, lymphoid hyperplasia, or acute appendicitis was present or when the appendix was normal. Bacteroides was isolated twice as often in perforated appendicitis.The incidence of wound infection was 19% and varied according to the state of the appendix, being 63% in perforated appendicitis and 9.5% where lymphoid hyperplasia was present. Bacteroides was isolated from over 90% of the wound infections.In the patients with perforated appendicitis where effective chemotherapy was given the incidence of wound infection was 15% whereas in untreated or inappropriately treated patients it was over 50%.The isolation of bacteroides requires special precautions to be taken both in the collection of the specimen and laboratory culture. It is important that the chemotherapy of postappendicectomy infections include an antibiotic active against bacteroides.     

Haemophilus ducreyi requires an intact flp gene cluster for virulence in humans

An intact Haemophilus ducreyi flp operon is essential for microcolony formation in vitro. tadA is the 9th of 15 genes in the operon and has homology to NTPases of type IV secretion systems. Fifteen human volunteers were experimentally infected with both H. ducreyi 35000HP and the tadA mutant, 35000HP.400. Papules developed at similar rates at sites inoculated with the mutant and parent, while pustules formed at 36.4% of parent sites and at 0% of mutant sites (P = 0.001). Compared to 35000HP, 35000HP.400 had only a modest but significant reduction in lesion scores in the temperature-dependent rabbit model of chancroid. These data suggest that proteins secreted by the flp locus are required for full expression of virulence by H. ducreyi in humans but have less of a role in virulence in an animal model of infection.     

Langerhans' cell expression of the selectin ligand, sialyl Lewis x.

Cellular adhesion molecules play a central role in leucocyte migration through peripheral blood and tissues. A crucial stage in these events in selectin-mediated adhesion involving E-selectin expressed on activated endothelium interacting with a range of carbohydrate ligands expressed by specific subpopulations of leucocytes. As such mechanisms may be relevant to bone marrow-derived dendritic epidermal Langerhans' cell (LC) migration, expression of these carbohydrate ligands was assessed immunocytochemically in whole skin biopsies and in epidermal cell suspensions obtained from adult humans. Double-labelling experiments revealed that sialyl Lewis x, recognized by the monoclonal antibody CSLEX1, was expressed on epidermal LC (n = 9). Furthermore, expression was enhanced at 24 hr following epicutaneous application of antigen and in the inflammatory disorder psoriasis (n = 10). E-selectin was concomitantly strongly expressed on dermal endothelium in psoriasis and allergic contact dermatitis. Intradermal injection of the T-cell-derived cytokine interferon-gamma (IFN-gamma) led to increased LC expression of sialyl Lewis x. In epidermal cell suspensions, in contrast to keratinocytes, CD1a+ cells expressed sialyl Lewis x, intensity of which was enhanced after 4 days in culture. CSLEX1 staining could be abolished and CD15 (non-sialated Lewis x) expression induced by saponification and treatment with neuraminidase. Expression of other selectin ligands was also examined. While the cutaneous lymphocyte antigen defined by the monoclonal antibody HECA-452 reacted with a small minority of LC, sialyl Lewis a and sulphatide were not expressed under any experimental conditions. These studies indicate that E-selectin-sialyl Lewis x interactions are potentially important in LC migration, both into and out of skin.     

Pathologic explanation for postoperative obstipation in Hirschsprung's disease revealed with monoclonal antibody staining

Until now, no pathologic explanation could be found for the postoperative obstipation occurring in some patients with intestinal aganglionosis. Twenty-two of 108 infants treated for intestinal aganglionosis suffered from postoperative obstipation. Resected material from these 22 patients and from 17 control subjects was investigated with monoclonal anti-neurofilament antibody staining. An abnormal staining pattern was revealed in 18 of the constipated patients. Consequently, this new immunohistochemical staining technic has revealed a hitherto unsuspected cause for postoperative obstipation in aganglionosis. The monoclonal antibody may provide early warning of such postoperative constipation.