Infective skin conditions in an adult sea-going population.

Infective skin conditions represent a significant element of the caseload for sea-going and shore-side clinicians. They are common within the wider military setting due to the frequent requirement to live in close proximity to others in conditions which favour the spread of skin and soft tissue infections (SSTI). Within the UK civilian population, 24% of individuals see their family doctor for skin conditions each year, accounting for 13 million primary care consultations annually. Of these, almost 900,000 were referred to dermatologists in England in 2009-2010 and resulted in 2.74 million secondary care consultations. Several recent articles have highlighted the problem of Panton-Valentine Leukocidin Staphylococcus aureus (PVL-SA) infection and carriage in sailors on submarines, and soldiers deployed to Afghanistan. However, the majority of published articles relate to land-based military personnel. This article aims to provide an overview of the most common infective skin conditions presenting among Naval personnel (based on the authors' experience), illustrated by several case studies, together with an approach to their diagnosis and management.

Addition of Povidone-Iodine to Fluoride Varnish for Dental Caries: A Randomized Clinical Trial.

INTRODUCTION: Dental caries is the most common chronic childhood disease. Products of metabolism by bacteria populating the tooth surface induce development and progression of cavities. OBJECTIVES: We sought to determine whether a polyvinylpyrrolidone-iodine (PVP-I; povidone-iodine) and NaF topical varnish was superior to one containing only NaF in prevention of new dental caries lesions in a single-center randomized active-controlled trial based on a double-blind, parallel-group design. METHODS: The site was Pohnpei State, Federated States of Micronesia. The study population was healthy children 49 to 84 mo old who were enrolled in early childhood education: 284 were randomized (1:1 allocation), and 273 were included in year 1 analysis and 262 in year 2. The test varnish contained 10% PVP-I and 5.0% NaF. The comparator contained only 5.0% NaF but was otherwise identical. Varnishes were applied every 3 mo during 2 y. The primary outcome was the surface-level primary molar caries lesion increment (d2-4mfs) at 2 y. Caries lesion increments from baseline to year 1 and year 2 were compared between conditions with log-linear regression, adjusting for age and sex and whether the tooth was sound at baseline (free of caries lesions). RESULTS: At year 1, the caries lesion increment for primary molars sound at baseline was 0.9 surfaces (SD = 1.5) for the test varnish versus 1.8 (SD = 2.2) for the comparator varnish with fluoride alone (adjusted rate ratio, 0.50; 95% CI, 0.31 to 0.81; P = .005). At year 2, the caries lesion increment for primary molars sound at baseline was 2.3 surfaces (SD = 2.8) for the test varnish as compared with 3.3 (SD = 2.7) for the comparator (adjusted rate ratio, 0.74; 95% CI, 0.52 to 1.03; P = .073). Teeth that were already cavitated at baseline did not show a preventive effect. There were no harms. CONCLUSIONS: A dental varnish containing PVP-I and NaF is effective in the primary prevention of cavities in the primary dentition (NCT03082196). KNOWLEDGE TRANSFER STATEMENT: This study demonstrates that periodic application of a varnish containing NaF and PVP-I is effective in prevention of caries lesions and useful in assessing the potential of combined treatment.

Streptococcus gordonii's sequenced strain CH1 glucosyltransferase determines persistent but not initial colonization of teeth of rats.

OBJECTIVE: Extracellular glucan synthesis from sucrose by Streptococcus gordonii, a major dental plaque biofilm bacterium, is assumed important for colonization of teeth; but this hypothesis is un-tested in vivo. METHODS: To do so, we studied an isogenic glucosyltransferase (Gtf)-negative mutant (strain AMS12, gtfG(-)) of S. gordonii sequenced wild type (WT, strain Challis CH1, gtfG(+)), comparing their in vitro abilities to grow in the presence of glucose and sucrose and, in vivo, to colonize and persist on teeth and induce caries in rats. Weanling rats of two breeding colonies, TAN:SPFOM(OM)BR and TAN:SPFOM(OMASF)BR, eating high sucrose diet, were inoculated with either the WT (gtfG(+)), its isogenic gtfG(-) mutant, or reference strains of Streptococcus mutans. Control animals were not inoculated. RESULTS: In vitro, the gtfG(-) strain grew at least as rapidly in the presence of sucrose as its WT gtfG(+) progenitor, but formed soft colonies on sucrose agar, consistent with its lack of insoluble glucan synthesis. It also had a higher growth yield due apparently to its inability to channel carbon flow into extracellular glucan. In vivo, the gtfG(-) mutant initially colonized as did the WT but, unlike the WT, failed to persist on the teeth as shown over time. By comparison to three S. mutans strains, S. gordonii WT, despite its comparable ecological success on the teeth, was associated with only modest caries induction. Failure of the gtfG(-) mutant to persistently colonize was associated with slight diminution of caries scores by comparison with its gtfG(+) WT. CONCLUSIONS: Initial S. gordonii colonization does not depend on Gtf-G synthesis; rather, Gtf-G production determines S. gordonii's ability to persist on the teeth of sucrose-fed rats. S. gordonii appears weakly cariogenic by comparison with S. mutans reference strains.

Streptococcus mutans: fructose transport, xylitol resistance, and virulence.

Streptococcus mutans, the primary etiological agent of human dental caries, possesses at least two fructose phosphotransferase systems (PTSs), encoded by fruI and fruCD. fruI is also responsible for xylitol transport. We hypothesized that fructose and xylitol transport systems do not affect virulence. Thus, colonization and cariogenicity of fruI(-) and fruCD(-) single and double mutants, their WT (UA159), and xylitol resistance (X(r)) of S. mutans were studied in rats fed a high-sucrose diet. A sucrose phosphorylase (gtfA(-)) mutant and a reference strain (NCTC-10449S) were additional controls. Recoveries of fruI mutant from the teeth were decreased, unlike those for the other strains. The fruCD mutation was associated with a slight loss of cariogenicity on enamel, whereas mutation of fruI was associated with a loss of cariogenicity in dentin. These results also suggest why xylitol inhibition of caries is paradoxically associated with spontaneous emergence of so-called X(r) S. mutans in habitual human xylitol users.

Sucrose transport by Streptococcus mutans. Evidence for multiple transport systems.

The transport of sucrose by selected mutant and wild-type cells of Streptococcus mutans was studied using washed cocci harvested at appropriate phases of growth, incubated in the presence of fluoride and appropriately labelled substrates. The rapid sucrose uptake observed cannot be ascribed to possible extracellular formation of hexoses from sucrose and their subsequent transport, formation of intracellular glycogen-like polysaccharide, or binding of sucrose or extracellular glucans to the cocci. Rather, there are at least three discrete transport systems for sucrose, two of which are phosphoenolpyruvate-dependent phosphotransferases with relatively low apparent Km values and the other a non-phosphotransferase (non-PTS) third transport system (termed TTS) with a relatively high apparent Km. For strain 6715-13 mutant 33, the Km values are 6.25 X 10(-5) M, 2.4 X 10(-4) M, and 3.0 X 10(-3) M, respectively: strain NCTC-10449, the Km values are 7.1 X 10(-5) M, 2.5 X 10(-4) M and 3.3 X 10(-3) M, respectively. The two lower Km systems could not be demonstrated in mid-log phase glucose-adapted cocci, a condition known to repress sucrose-specific phosphotransferase activity, but under these conditions the highest Km system persists. Also, a mutant devoid of sucrose-specific phosphotransferase activity fails to evidence the two high affinity (low apparent Km) systems, but still has the lowest affinity (highest Km) system. There was essentially no uptake at 4 degrees C indicating these processes are energy dependent. The third transport system, whose nature is unknown, appears to function under conditions of sucrose abundance and rapid growth which are known to repress phosphoenolpyruvate-dependent sucrose-specific phosphotransferase activity in S. mutans. These multiple transport systems seem well-adapted to S. mutans which is faced with fluctuating supplies of sucrose in its natural habitat on the surfaces of teeth.

Detection of monosomy 7 and trisomies 8 and 11 in myelodysplastic disorders by interphase fluorescent in situ hybridization. Comparison with acute non-lymphocytic leukemias.

Cells from 50 patients with myelodysplastic syndrome (MDS) and 20 patients with acute non-lymphoblastic leukemia (ANLL) were studied by fluorescent in situ hybridization (FISH) using alphoid biotinylated probes to detect numerical chromosome 7, 8 and 11 aberrations in interphase nuclei. FISH data were compared with cytogenetic results. Both methods were in agreement in 25/50 MDS and 20/20 ANLL cases. Trisomy 11 was found neither by cytogenetic study nor by FISH. In 11 MDS patients the percentage of abnormal cells was higher by FISH than by classical cytogenetic analysis. FISH revealed monosomy 7 which was undetectable by karyotypic study in 5-22% cells from 15 MDS patients. It also allowed the identification of two small markers and a ring chromosome in two MDS cases. FISH hence appears to be useful for the detection of minor abnormal clones and is a convenient complement to conventional cytogenetic analysis in the study of MDS.

Chronic myelocytic leukaemia with unusual (27 years) complete remission terminating in acute undifferentiated leukaemia: a clinical and karyotypic study.

A case of clinically typical CML (300 x 10(6)/l leukocytes, 400 x 10(6)/l platelets, splenomegaly) is presented. After complete remission induced by busulphan, no clinical or haematological abnormalities were observed for 27 years until the development of acute leukaemia (type M1), which was rapidly fatal after a brief chemotherapy-induced remission. The cytogenetic findings were also original: no chromosome Ph1 (during remission 3 years after the onset of the disease), no translocation (banding study 5 years later), and no bcr/abl rearrangement (during the terminal phase).

Two additional cases of t dic(9:12) in acute lymphocytic leukemia (ALL): prognosis in ALL with dic(9:12).

We report two occurrences of dic(9;12) in acute lymphoblastic leukemia and review previous cases. Cases of dic(9;12) share common features with cases of 9p and 12p rearrangements, but prognosis seems particularly good in cases of dic(9;12). The persistence of a specific dicentric in stable clones is remarkable and points to unusual centromeric behavior and/or marked selective advantage of the anomaly.

Enrichment of human marrow T-cell precursors by complement-dependent cytotoxicity with monoclonal antibodies and Percoll Gradient centrifugation.

Attempts to enrich and characterize human marrow T-cell precursors have been performed using discontinuous Percoll gradient centrifugation, phenotypic analysis of cells with monoclonal antibodies (Mabs), and T-cell colony-forming capacity. Marrow cells were extensively depleted of T cells and separated into seven fractions. The depletion was performed with the following Mabs: CD6 (MBG6 or RFT12) + CD8 (RFT8), CD2 (D66) + CD8 (RFT8), and CD6 (RFT12) + CD8 (RFT8) + CD7 (RFT2). A peak of cells with the capacity to differentiate into mature CD2+CD4+ T-cell agar colonies (TL-CFU) was obtained in a fraction with a density 1.063 less than d less than 1.069 g/ml. This peak was associated with the presence of cells expressing RFB1 and OKT10, two markers shared by hemopoietic precursors. Cells in this fraction were negative for CD3, CD4, CD1, CD8, and CD2 antigens. Their treatment by complement-dependent cytotoxicity with the CD7 Mab resulted in a loss of T-cell colony-forming capacity together with a reduction of T10-, RFB1-, and My10-positive cells.

Studies on human prothymocytes by means of an agar T-cell colony assay.

The identity of bone marrow (BM) T colony-forming cells has led to controversy because of BM contamination with mature T cells having clonogenic potential. To circumvent this problem, extensive purging of BM cells was achieved, using E-rosetting and complement-dependent cytotoxicity, with a cocktail of monoclonal antibodies (Mabs): CD6 + CD8 + CD4 + CD2 and two successive rabbit Complement (C) treatments. This resulted in a 2-log elimination of mature T cells, as assessed by marker studies. T-cell-depleted marrow (TDBM) was plated in agar in the presence of PHA- and B+ null cell-derived prothymocyte differentiating activity (PTDA). Two peaks of colony formation were observed on days 7 and 10 of incubation. Both seven- and ten-day colonies contained mainly T4+ and only a few T8+ cells, which also expressed T3, T11, HLA-DR, and Tac antigens. These colony-forming cells were enriched (three- to fourfold) by discontinuous Percoll gradient centrifugation. These results point to the existence of marrow T-cell progenitors, which differ in their kinetics of colony generation and surface markers.

Signal requirements for the generation of T-lymphocytes from T-depleted bone marrow cells: a sequential study.

We have investigated the sequence of signals provided by a B- and null-cell-derived prothymocyte-differentiating activity (PTDA), phytohemagglutinin (PHA), and interleukin 2 (IL2) to the generation of mature T-lymphocytes by T-depleted bone marrow (BM) cells. Sequential studies show that preincubation of CD2-, CD3-, CD4-, CD6-, and CD8- BM cells with PTDA, but not with recombinant (r) IL2 or PHA increased their capacity to proliferate in liquid culture and to form agar T-cell colonies provided both PHA and rIL2 were added to the cultures. In contrast, the growth of T-cell-containing BM was significantly enhanced in both liquid and agar culture following its preincubation with rIL2 as well as with PTDA. The selective effect of PTDA on CD2-, CD3-, CD4-, CD6-, CD8- BM cells was abolished by adding a CD7 monoclonal antibody to the T-cell-purging coctail. Cell marker studies performed on T-cell-depleted BM-derived liquid or agar cultures have shown that they contain up to 70%-85% CD2+, CD3+, CD4+, CD8- cells. No IL1 or IL2 could substitute for PTDA, nor have these activities, as well as interferon (IFN), IL3, IL4, or granulocyte-macrophage colony-stimulating activity (GM-CSA) been detected so far in PTDA-containing preparations. These results indicate that PTDA can trigger marrow T-cell precursors into PHA-responsive T cells, which, following activation by PHA, require IL2 for growth. It is suggested that this may represent a thymus-independent alternative pathway for T-cell differentiation and activation.

The nature of cell interactions during phytohemagglutinin-induced T-cell colony formation.

When a constant number of peripheral human blood mononuclear cells (MC) are seeded in an agar overlayer on top of a cell free underlayer supplemented with 100 microgram phytohemagglutinin (PHA), the number of colonies formed is dependent on cell concentration with respect to both the overlayer and total culture volumes. These results support the view that during PHA-induced colony formation cell cooperation between T-colony forming cells and a population of cooperating cells (CC) is mediated by diffusible soluble mediators. They also indicate that the effect of such mediators is dependent on concentration and not only on total amount in the culture. With respect to contradictory evidence on the nature of CC the possible heterogeneity of the CC population has been explored using the mathematical approach developed by Copplesson and Michie to investigate cell cooperation during an in vitro immune response. As a result, the slopes of the regression lines obtained by plotting the logarithms of the number of colonies obtained against the logarithms of cell inocula suggest the possibility of at least 3 interacting cell populations during colony formation, and thus the heterogeneity of cooperating cells. It is therefore hypothesized that T-cell colony formation may be under the control of a fairly complex system of mediators exchanged by different types of CC rather than by one specific colony stimulating factor as described during granulocyte or macrophage colony growth.

Trochanter bone marrow: a source of normal human colony forming cells.

In vitro studies of human hemopoiesis are often limited by the availability of normal bone marrow. We have overcome this difficulty by taking advantage of the bone marrow fragments removed during total hip replacement. We report here a comparative study of the colony forming capacity of trochanter and sternal or iliac crest marrow from five hematologically normal donors. Our data indicate that trochanter marrow is a reliable source of normal in vitro granulocyte/macrophage colony forming cells.

Role of p53 and RB on in vitro growth of normal umbilical cord blood cells.

Human umbilical cord blood (UCB) is rich in hematopoietic stem cells and progenitors and recently has been used in the clinic as an alternative source for graft and marrow repopulation. We tried to determine in vitro the roles of wild-type (wt) p53 and wt RB tumor/growth suppressor genes in the regulation of proliferation and maturation of hematopoietic UCB cells. CD34+ cells, isolated from mononuclear cells of UCB, were cultured in semisolid medium under conditions that favor growth of hematopoietic cells. We studied the level of expression of p53 and RB mRNAs and proteins during cell culture by Northern blot and cytofluorometry analysis, respectively. Sense (S), antisense (AS), or scrambled (missense [MS]) p53 and RB oligodeoxynucleotides (ODNs) were used to study the behavior of these cells in the absence of expression of p53 and/or RB. Adequate doses of p53 or RB ODNs inducing maximal inhibitory effect were used to study the behavior of these cells in the absence of expression of p53 and/or RB. Adequate doses of p53 or RB ODNs inducing maximal inhibitory effect with minimal cellular toxicity were determined. Exposure of CD34+ cells to p53 or AS, RB AS, or both p53 and RB AS but not other ODNs (sense or missense) resulted in a significantly increased number of colony-forming units-granulocyte/macrophage (CFU-GM) induced by interleukin-3 (IL-3) and/or granulocyte-macrophage colony-stimulating factor (GM-CSF). The number of erythroid colonies (CFU-E) and burst-forming units (BFU-E) derived from CD34+ cells in the presence of erythropoietin (Epo) was not significantly increased, whereas the number of such colonies was markedly increased in the presence of IL-3 + EPO upon p53 AS and/or RB AS treatment with hypothesis that wt p53 and RB are proliferation suppressor genes that interfere with normal maturation of hematopoietic cells.

Identification of several rod loci and cloning of the rodD locus of Streptococcus mutans.

Previous work has shown that Streptococcus mutans is normally a short rod or a sphere, depending on its environment. This paper describes two distinct genetic approaches used to identify multiple loci and isolate one locus, rodD, controlling S. mutans rod shape. The first method involved isolation of a group of rod- mutants caused by transposon Tn916 insertion, and analysis of the inactivated genes by Southern hybridization. The second method involved mutagenesis via a shotgun insertion-duplication technique, isolation of a rod- mutant, and cloning the intact rod locus, employing an integration shuttle plasmid, pVA891. These approaches have led to the identification of multiple rod loci involved in determining the rod shape of S. mutans, and also cloning of one rod locus, rodD. The cloning strategy may also be useful for cloning other streptococcal genes which cannot be detected by their expression in Escherichia coli.

Four additional cases of trisomy 14 as the sole anomaly in various haematological malignancies.

We report on four cases of trisomy 14 as the sole anomaly. Three cases were myelodysplastic syndromes and one was a non-Hodgkin's lymphoma. This anomaly is mainly in myeloid disorders and still remains to be well documented. On the other hand, we show this anomaly to be also a non-random anomaly in lymphoproliferative disorders.

The 8p11 anomaly in "monoblastic" leukaemia.

We report on three cases of monoblastic leukaemia with a chromosomal breakpoint at 8p11. One of our cases exhibited a translocation t(8;16) as has been described in 12 previous cases reported in 1987. The two other cases showed respectively t(6;8) and t(8;19) and they seem to be the first two reports of variant translocation in this disease. The available cases serve to define the main characteristics of this new subtype of non lymphocytic acute leukaemia: phagocytosis in most of the cases, the possible involvement of a granulomonocytic precursor, and a common breakpoint in 8p11.

Chromosome 6p rearrangements appear to be secondary changes in various haematological malignancies.

We report on six cases of 6p rearrangement in various haematological malignancies. On reviewing the literature, we assume 6p rearrangements to be secondary anomalies in both myeloid and lymphoid malignancies, and confirm it to be strongly associated with -5/del (5q) in myelodysplastic syndromes.