16S rRNA-targeted oligonucleotide probes for the in situ detection of members of the phylum Cytophaga-Flavobacterium-Bacteroides

Bacteria of the Cytophaga-Flavobacterium-Bacteroides phylum (CFB-phylum) are numerically important members of many microbial communities. A suite of five 16S rRNA-targeted oligonucleotide probes for members of this group is described which was designed to dominantly target bacteria of the CFB-phylum that are found in particular habitats. For this we initially performed a literature survey-for the sources and sites of isolation of hitherto described members of the CFB-phylum. Probe CFB286 is mostly complementary to the 16S rRNA of species originally isolated from freshwater habitats, however, detects some marine and soil isolates and is the only probe which includes some food isolates. Probe CFB563 detects marine as well as animal-associated isolates. Probe CFB719, which also detects some environmental isolates, and probe CFB972 are mostly targeting animal-associated isolates. All probes are complementary to a variety of human-associated species within the CFB-phylum which, in the data set investigated (October 1998), made up 46% of all 16S rRNA sequences from the CFB-phylum. We conclude that it is difficult to find habitat-specific probes for members of the CFB-phylum and that the design of probes for monophyletic groups should remain the standard approach. Applicability of the probes for fluorescence in situ hybridization and specificity for single cell detection were evaluated for the four mentioned probes whereas the fifth, probe CFB1082, which almost exclusively targets human-associated species, was not further characterized. The new probes are of limited determinative value and should be used together with the already established probes for the CFB-phylum. It is the hybridization pattern observed for a given cell or culture with the enlarged probe set that is suggestive for its affiliation with a defined group within the CFB-phylum.

The visible animal project: a three-dimensional, digital database for high quality three-dimensional reconstructions

The "Visible Animal Project" (VAP) is comprised of axial anatomic cryosections and corresponding CT and MR images of a mature dog. The digital database is used for the creation of three-dimensional computer graphics of canine anatomy. The technique of cryodissection is described in detail. The combining of the corresponding CT and MR images, and cryosections as well as the data processing for the creation of three-dimensional reconstructions is presented and examples are shown. For the first time a complete high-resolution three-dimensional database of a dog is available, which can be used as the base for further high quality three-dimensional reconstructions, similar to the "Visible Human Project" (VHP).

Bipolarity in children

Childhood and adolescent bipolar disorder have been less studied than adult onset bipolar illness. However, case reports of mania in childhood can be found as early as the mid 19th century. Historically, several factors have made the accurate diagnosis of bipolar disorder in childhood difficult: clinical bias against the diagnosis of mania in children; low base rate of disorder; symptom overlap between bipolar disorder and other more prevalent childhood-onset psychiatric disorders; and developmental constraints and variability in clinical presentation. The epidemiology of juvenile-onset bipolar disorder remains an open topic for research. The disorder appears to increase in prevalence with advancing age until young adulthood. Reported phenomenology of bipolar disorder in children and adolescents indicates a highly variable presentation with a developmental trend towards increased resemblance to the adult phenotype with increasing age of onset. Diagnostic accuracy for the disorder is improved by adherence to diagnostic and statistical manual of mental disorders (DSM) criteria and may be aided by structured or semistructured diagnostic interviews. The course of bipolar disorder in children and adolescents has also received limited systematic study. However, research to date supports a clinical picture of a relapsing, recurrent illness with substantial morbidity. Systematic studies of pharmacologic treatments of acute mania in children and adolescents are limited in number and scope. Clinical justification for the use of acute antimanic treatments such as lithium and valproic acid is still based upon studies conducted in adults. There remains an immediate and significant need for additional research into all aspects of juvenile-onset bipolar disorder.

Nitric oxide, skin growth and differentiation: more questions than answers?

Nitric oxide has varied effects on the skin. In this review the role of nitric oxide in cutaneous wound healing, apoptosis, carcinogenesis and psoriasis is discussed.

The response of the microbial community of marine sediments to organic carbon input under anaerobic conditions

Cyanobacterial biomass was added to anaerobic sediment to simulate the natural input of complex organic substrate that occurs in nature after algae blooms. Sediments were incubated at 0 degree C, 8 degrees C and 24 degrees C for 13 days. Community dynamics were measured by fluorescence in situ hybridisation (FISH), denaturing gradient gel electrophoresis (DGGE), and sequencing of 16S rDNA PCR products. Metabolic changes were followed by the analysis of total carbon mineralisation, sulfate reduction, and ammonium production rates. The addition of organic material resulted in significant changes in the composition of the microbial community at all temperatures tested. Sulfate reduction was the main mineralisation process detected. However, not sulfate-reducers but rather members of the Cytophaga-Flavobacterium phylogenetic cluster showed the highest increase in the bacterial cells as detected by FISH. We conclude that these organisms play an important role in the anaerobic decomposition of complex organic material perhaps because they are the main catalysts of macromolecule hydrolysis and fermentation. The molecular methods also indicated a stimulation of ribosome synthesis. The detection of a large number of rRNA-rich cells belonging to the Cytophaga-Flavobacterium phylogenetic cluster further supports the importance of their role in the degradation of complex organic material in anaerobic marine sediments. Their detection in high numbers in the field may indicate recent deposition events.

Comparison of radiography, scintigraphy and ultrasonography in the diagnosis of a case of temporomandibular joint arthropathy in a horse

Diagnosis of temporomandibular joint disease in the horse presents a challenge to the equine veterinarian. This case report illustrates a combined imaging approach using radiography, scintigraphy and ultrasonography in a horse with severe arthropathy of the left temporomandibular joint. Radiographs were inconclusive. Scintigraphy with Tc99m methylenediphosphonate localised, but failed to characterise the disease process; ultrasonography was the only imaging method which both localised and characterised the lesion. Ultrasonography proved to be a relatively cheap, technically easy to perform and non-invasive method for the assessment of the disease.

Psoriatic keratinocytes show reduced IRF-1 and STAT-1alpha activation in response to gamma-IFN

Psoriasis is a chronic inflammatory dermatosis characterized by hyperproliferative keratinocytes (KC). The skin lesions are infiltrated by T cells, which secrete gamma interferon (gamma-IFN) and are believed to be necessary to maintain the psoriatic phenotype. In normal KC, gamma-IFN is a potent inhibitor of proliferation, but proliferation of KC persists in psoriatic plaques despite the presence of gamma-IFN. Immunostaining of interferon regulatory factor-1 (IRF-1) revealed that IRF-1 was localized to the basal cells of the epidermis in normal and in nonlesional psoriatic skin, but was suprabasal or completely absent in lesional psoriatic skin. This finding led to the hypothesis that abnormal signaling in the gamma-IFN pathway may occur in psoriatic KC. To test this hypothesis, we measured activation of IRF-1 and signal transducer and activator of transcription (STAT)-1alpha transcription factors in KC after stimulation with gamma-IFN. Primary cultures of KC from normal and nonlesional psoriatic skin were stimulated with gamma-IFN and subsequent transcription factor activation was measured by electrophoretic mobility shift assay. Psoriatic KC showed a reduced induction of IRF-1 and STAT-1alpha activation after stimulation with gamma-IFN, compared with normal KC. Reduced activation of IRF-1 and STAT-1alpha in response to gamma-IFN indicates a fundamental defect in the growth and differentiation control of psoriatic KC in the absence of the influence of other cell types.

A randomized trial of acidified nitrite cream in the treatment of tinea pedis

BACKGROUND

Nitric oxide is continually released from normal skin and has antimicrobial effects. An acidified nitrite cream releases supraphysiologic concentrations of nitric oxide and is fungicidal in vitro.

OBJECTIVE

The purpose of this study was to assess the efficacy of an acidified nitrite cream as treatment for tinea pedis.

METHODS

Sixty patients were recruited with both a clinical diagnosis of tinea pedis and hyphae identified on direct microscopy; they were randomly placed into an active group treated with twice-daily application of a mixture of 3% salicylic acid in aqueous cream and 3% nitrite in aqueous cream for 4 weeks and a control group treated with 3% salicylic acid in aqueous cream and aqueous cream alone. Nineteen patients completed the trial in the active group and 16 patients in the control group. Mycologic cure (negative results on microscopy and culture) and clinical improvement were measured at 0, 2, and 4 weeks and after a 2-week interval with no treatment.

RESULTS

At the end of the treatment period, 18 of the 19 patients in the active group were mycologically cured as were 11 of 16 in the control group (p = 0.042). Two weeks after the cessation of treatment, 13 of 19 patients in the active group were mycologically cured and 5 of 16 in the control group (p = 0.028). The initial clinical scores in the active and control groups were 8.1 and 8.19 (two-tailed p = 0.95). At 4 weeks they were 1.66 and 6.0 (two-tailed p = 0.002) and after 2 weeks with no treatment 1.45 and 7.4 (two-tailed p < 0.0002).

CONCLUSION

Acidified nitrite is effective therapy for tinea pedis.

Tonsillitis and chronic psoriasis

Although the relationship between streptococcal tonsillitis and acute guttate psoriasis is well recognized, its relationship to chronic forms of psoriasis is less established. In order to explore this further, the authors questioned 35 patients with severe psoriasis and 35 age-matched eczema controls about their history of significant sore throats (i.e. requiring a GP visit) and any resultant worsening of the skin condition. A third of the psoriasis patients reported recurrent sore throats which worsened their skin condition. This was true of only one (3%) of the 35 eczema controls. The authors discuss these findings in the context of recent laboratory work on the association between streptococcal infection and psoriasis.

Detection of nitric oxide and nitric oxide synthases in psoriasis

Biopsies from psoriasis lesions and clinically uninvolved skin of eight patients and five normal subjects were studied by immunocytochemistry with computerized image analysis for the presence of endothelial, neuronal and inducible isoforms of nitric oxide synthase. Endothelial nitric oxide synthase was expressed in the endothelium and weakly in some keratinoctyes. Its expression was not significantly different in psoriasis. Inducible nitric oxide synthase, however, was absent from normal skin but was significantly upregulated in psoriatic lesional skin, focally in keratinocytes but to the greatest extent in the papillary dermis and to a lesser extent in clinically uninvolved psoriatic skin. Inducible nitric oxide synthase staining was greatest in the more severe lesions and correlated with the inflammatory infiltrate (CD3-positive cells) and with keratinocyte proliferation (Ki-67-positive cells). In normal skin, neuronal nitric oxide synthase was expressed only in keratinocytes in the granular layer and eccrine sweat glands. However, in psoriasis and clinically uninvolved skin the neuronal form was present through all levels of the epidermis. Direct measurement of nitric oxide production from the skin surface revealed a tenfold increase in the lesions of 16 psoriatic patients compared with their nonlesional skin, and this nitric oxide production was inhibited by topical betamethasone.

Nitric oxide--a newly discovered chemical transmitter in human skin

Nitric oxide (NO) is synthesized by many cells in the body. Low concentrations of NO have homeostatic roles in the circulation and nervous system, whereas high concentrations are biocidal, cytocidal and have immunomodulatory roles. The place of NO in the skin has recently become the focus of much attention, and this review highlights studies on the part played by NO in health and disease.

A comparison of subjective and objective measures of reduction of psoriasis with the use of ultrasound, reflectance colorimetry, computerized video image analysis, and nitric oxide production

BACKGROUND

Studies of antipsoriatic therapy often rely on subjective scoring. Objective measures have been developed but have not previously been compared with subjective scoring.

OBJECTIVE

Our purpose was to compare subjective and objective measures of reduction of psoriasis with topical therapy.

METHODS

A 2-week, double-blind, left-to-right comparative trial of betamethasone valerate against white soft paraffin was performed in 12 patients. The subjective scores were erythema, elevation, scale, and a composite total. Objective measures were nitric oxide production measured by chemiluminescence; erythema reflectance; ultrasound scan for thickness, scale, and echo-poor zone; and computerized image analysis of video images.

RESULTS

Subjective and objective measures had similar power to detect therapeutic effect. The subjective measures showed greater variation and relatively overestimated improvement. There was correlation between measures and estimates for area, redness, and thickness. Nitric oxide production was the most powerful objective measure.

CONCLUSION

Thickness determined by ultrasound scan and nitric oxide production are useful measures of reduction of psoriasis, which lend themselves to more powerful statistical tests than subjective interval data.