Mycology of Onychomycosis: A 5-year retrospective review (2011 - 2015) in Hospital Kuala Lumpur

Onychomycosis is a common nail disease with numerous etiological pathogens. In order to determine and trend the local mycological pattern of culture-positive diseased nail samples sent from the Department of Dermatology, Hospital Kuala Lumpur, a five-year retrospective audit was carried out, which revealed that non-dermatophyte molds were the predominant fungi isolated, followed by yeasts and dermatophytes. This is similar to two previous studies in Malaysia, but varies greatly from other studies around the world which showed a dermatophyte-predominant prevalence. This could be due to the nature of the environment our patients encountered.

Hearing results in adults after stapedotomy

Background:

Although clinical otosclerosis is considered a rare disease, it is the common cause of hearing loss in patients with an intact tympanic membrane. Also, the hearing loss is amenable to other non-surgical remedies. However, stapes surgery is currently the preferred treatment modality. This study aimed to assess the short-term hearing results in adults after primary stapedotomy, and find, if any, the effects of some variables on post operative hearing.

Materials and Methods:

This was a retrospective review of the clinical records of all consecutive patients who had primary stapedotomy for otosclerosis at the K. K. Ramalingam Ear, Nose and Throat Hospital and Research institute, Chennai, India between October 2011 and December 2011.

Results:

A total of 31 adults were studied; 19 (61.3%) were males and 12 (38.7%) were females. Their ages were between 21 years and 69 years; the mean age was 43.67 years, standard deviation (SD) 11.859 (95% CI; 39.24-48.10). The mean duration of symptom was 5.96 years; SD 6.188 (95% CI; 3.65-8.27). The commonest presenting symptoms were hearing loss (96.5%) and tinnitus (48.4%). The overall mean pre-operative pure tone average was 56.54 dB, SD 10.866 (95% CI; 52.55-60.52), while the overall mean post operative pure tone average was 33.75 dB, SD 15.577 (95% CI; 28.03-39.46). This difference was found to be statistically significant (Z = −4.454; P = 0.000). The overall mean pre-operative air bone gap was 43.14 dB; SD 6.824 (95% CI; 40.64-45.64) and the overall mean post operative air bone gap was 19.17 dB; SD 12.368 (95% CI; 14.63-23.70). This difference was found to be statistically significant (Z = −4.701). Nineteen patients (61.3%) had post operative air bone closure within 15 dB. The patient's age significantly correlated with the post operative pure tone average (r = 0.443; P = 0.023). There was no significant correlation between the duration of disease and the post operative pure tone average (r = −0.034; P = 0.870).

Conclusions:

Primary stapedotomy was effective in improving short term hearing outcome in adults with clinical otosclerosis. In addition, the post operative hearing outcomes were not affected by the duration of the disease; but by an increase in the patient's age.

Post-translational loss of renal TRPV5 calcium channel expression, Ca(2+) wasting, and bone loss in experimental colitis

BACKGROUND & AIMS

Dysregulated Ca(2+) homeostasis likely contributes to the etiology of inflammatory bowel disease-associated loss of bone mineral density. Experimental colitis leads to decreased expression of Klotho, a protein that supports renal Ca(2+) reabsorption by stabilizing the transient receptor potential vanilloid 5 (TRPV5) channel on the apical membrane of distal tubule epithelial cells.

METHODS

Colitis was induced in mice via administration of 2,4,6-trinitrobenzenesulfonic acid (TNBS) or transfer of CD4(+)interleukin-10(-/-) and CD4(+), CD45RB(hi) T cells. We investigated changes in bone metabolism, renal processing of Ca(2+), and expression of TRPV5.

RESULTS

Mice with colitis had normal serum levels of Ca(2+) and parathormone. Computed tomography analysis showed a decreased density of cortical and trabecular bone, and there was biochemical evidence for reduced bone formation and increased bone resorption. Increased fractional urinary excretion of Ca(2+) was accompanied by reduced levels of TRPV5 protein in distal convoluted tubules, with a concomitant increase in TRPV5 sialylation. In mouse renal intermedullary collecting duct epithelial (mIMCD3) cells transduced with TRPV5 adenovirus, the inflammatory cytokines tumor necrosis factor, interferon-γ, and interleukin-1β reduced levels of TRPV5 on the cell surface, leading to its degradation. Cytomix induced interaction between TRPV5 and UBR4 (Ubiquitin recoginition 4), an E3 ubiquitin ligase; knockdown of UBR4 with small interfering RNAs prevented cytomix-induced degradation of TRPV5. The effects of cytokines on TRPV5 were not observed in cells stably transfected with membrane-bound Klotho; TRPV5 expression was preserved when colitis was induced with TNBS in transgenic mice that overexpressed Klotho or in mice with T-cell transfer colitis injected with soluble recombinant Klotho.

CONCLUSIONS

After induction of colitis in mice via TNBS administration or T-cell transfer, tumor necrosis factor and interferon-γ reduced the expression and activity of Klotho, which otherwise would protect TRPV5 from hypersialylation and cytokine-induced TRPV5 endocytosis, UBR4-dependent ubiquitination, degradation, and urinary wasting of Ca(2+).

Acute interstitial nephritis due to proton pump inhibitors

Proton pump inhibitors (PPI) are commonly prescribed for dyspepsia and acid peptic disease. Acute interstitial nephritis (AIN) is an uncommon though important side-effect of these classes of drugs. We describe four cases: three females and one male. PPIs implicated were pantoprazole in two, omeprazole and esomeprazole in one each. AIN developed after an average period of 4 weeks of drug therapy. The symptoms were vomiting, loin pain, and oliguria. Minimal proteinuria with pyuria were seen and the mean serum creatinine was 4.95 ± 4 mg/dl. Two patients required hemodialysis. Renal biopsy showed interstitial mononuclear, plasma cell and eosinophilic infiltrates in all cases. PPI was stopped and steroids were started in all. Renal recovery was total in two and partial in two. A high index of suspicion is required to diagnose PPI induced AIN. Renal biopsy for confirmation followed up by prompt steroid therapy results in renal functional improvement.

High vitamin D3 diet administered during active colitis negatively affects bone metabolism in an adoptive T cell transfer model

Decreased bone mineral density (BMD) represents an extraintestinal complication of inflammatory bowel disease (IBD). Vitamin D₃ has been considered a viable adjunctive therapy in IBD. However, vitamin D₃ plays a pleiotropic role in bone modeling and regulates the bone formation-resorption balance, depending on the physiological environment, and supplementation during active IBD may have unintended consequences. We evaluated the effects of vitamin D₃ supplementation during the active phase of disease on colonic inflammation, BMD, and bone metabolism in an adoptive IL-10-/- CD4⁺ T cell transfer model of chronic colitis. High-dose vitamin D₃ supplementation for 12 days during established disease had negligible effects on mucosal inflammation. Plasma vitamin D₃ metabolites correlated with diet, but not disease, status. Colitis significantly reduced BMD. High-dose vitamin D₃ supplementation did not affect cortical bone but led to a further deterioration of trabecular bone morphology. In mice fed a high vitamin D₃ diet, colitis more severely impacted bone formation markers (osteocalcin and bone alkaline phosphatase) and increased bone resorption markers, ratio of receptor activator of NF-κB ligand to osteoprotegrin transcript, plasma osteoprotegrin level, and the osteoclast activation marker tartrate-resistant acid phosphatase (ACp5). Bone vitamin D receptor expression was increased in mice with chronic colitis, especially in the high vitamin D₃ group. Our data suggest that vitamin D₃, at a dose that does not improve inflammation, has no beneficial effects on bone metabolism and density during active colitis or may adversely affect BMD and bone turnover. These observations should be taken into consideration in the planning of further clinical studies with high-dose vitamin D₃ supplementation in patients with active IBD.

Hearing Results Post Tympanoplasty: Our Experience with Adults at the KKR ENT Hospital, India

Chronic suppurative otitis media is often associated with some degree of hearing loss. Tympanomastoid surgery is considered effective in controlling infection and preventing recurrence. However, opinions differ with regards the post-operative hearing results. This study aims to assess the hearing results, and also ascertain the effects of some variables on hearing in adult patients with chronic suppurative otitis media after primary tympanoplasty. This was a retrospective review of the clinical records of adult patients with chronic suppurative otitis media, who had primary tympanoplasty at the KKR ENT Hospital and Research Institute in Chennai (India), between 1st June and 30th September, 2011. A total of 26 adult patients with a mean age of 35.85 years (SD 14.775) were studied. There were 16 males (61.54 %) and 10 females (38.46 %). The commonest presenting symptoms were ear discharge (80.8 %) and hearing loss (76.9 %); and the mean duration of symptom was 8.52 years (SD 8.599). The overall mean pre-operative pure tone average was 49.58 dB (SD 18.608), while the overall mean post-operative pure tone average was 37.38 dB (SD 17.837). The difference between the overall mean pre- and post-operative pure tone average (hearing gain) was 12.192 dB (SD 12.924); and this was found to be statistically significant (p < 0.05). Multiple linear regression model showed that only increasing age was significantly associated with increasing mean post-operative pure tone average. This study found primary tympanoplasty effective in improving hearing results in adults with chronic suppurative otitis media even in those with advanced ossicular lesions.

NHE3 modulates the severity of colitis in IL-10-deficient mice

NHE3, the major intestinal Na(+)/H(+) exchanger, was shown to be downregulated and/or inhibited in patients with inflammatory bowel disease (IBD), a phenomenon believed to contribute to inflammation-associated diarrhea. NHE3(-/-) mice spontaneously develop colitis and demonstrate high susceptibility to dextran sulfate-induced mucosal injury. We investigated the effects of NHE3 deficiency on the development of chronic colitis in an IL-10 knockout (KO) mouse model of Crohn's disease. NHE3(-/-) mice were first backcrossed to 129/SvEv mice for >10 generations, with no apparent changes in their survival or phenotype. These mice were crossed with IL-10(-/-) mice on the same genetic background, and the phenotypes of 10-wk-old wild-type (WT), IL-10(-/-), NHE3(-/-), and IL-10(-/-)/NHE3(-/-) (double-KO) mice were studied. Histological and immunohistochemical examination of the colon established important architectural alterations, including increased neutrophilic and mononuclear cell infiltration in double- compared with single-KO mice. Double-KO mice demonstrated increased colonic expression of neutrophil collagenase matrix metalloproteinase-8 and the chemokines macrophage inflammatory protein-2, CXCL1, CXCL10, and CXCL11. Colonic IFNγ, IL-17, and IL-12/23 p40 protein secretion was significantly increased in double- compared with single-KO mice. IL-10(-/-)/NHE3(-/-) mouse colonic epithelium exhibited increased hallmarks of apoptosis, including a significantly increased number of cleaved caspase-3-positive surface epithelial cells. These results highlight the importance of NHE3 in the maintenance of intestinal barrier integrity and in modulating the inflammatory process in IL-10-deficient mice. Chronic NHE3 inhibition or underexpression observed in IBD may therefore contribute to the pathogenesis of IBD by influencing the extent of the epithelial barrier defect and affect the ultimate degree of inflammation.

Modulation of neutrophil motility by curcumin: implications for inflammatory bowel disease

BACKGROUND

Neutrophils (PMN) are the first cells recruited at the site of inflammation. They play a key role in the innate immune response by recognizing, ingesting, and eliminating pathogens and participate in the orientation of the adaptive immune responses. However, in inflammatory bowel disease (IBD) transepithelial neutrophil migration leads to an impaired epithelial barrier function, perpetuation of inflammation, and tissue destruction via oxidative and proteolytic damage. Curcumin (diferulolylmethane) displays a protective role in mouse models of IBD and in human ulcerative colitis, a phenomenon consistently accompanied by a reduced mucosal neutrophil infiltration.

METHODS

We investigated the effect of curcumin on mouse and human neutrophil polarization and motility in vitro and in vivo.

RESULTS

Curcumin attenuated lipopolysaccharide (LPS)-stimulated expression and secretion of macrophage inflammatory protein (MIP)-2, interleukin (IL)-1β, keratinocyte chemoattractant (KC), and MIP-1α in colonic epithelial cells (CECs) and in macrophages. Curcumin significantly inhibited PMN chemotaxis against MIP-2, KC, or against conditioned media from LPS-treated macrophages or CEC, a well as the IL-8-mediated chemotaxis of human neutrophils. At nontoxic concentrations, curcumin inhibited random neutrophil migration, suggesting a direct effect on neutrophil chemokinesis. Curcumin-mediated inhibition of PMN motility could be attributed to a downregulation of PI3K activity, AKT phosphorylation, and F-actin polymerization at the leading edge. The inhibitory effect of curcumin on neutrophil motility was further demonstrated in vivo in a model of aseptic peritonitis.

CONCLUSIONS

Our results indicate that curcumin interferes with colonic inflammation partly through inhibition of the chemokine expression and through direct inhibition of neutrophil chemotaxis and chemokinesis.

Upregulation of transcription factors in lung in the early phase of postpneumonectomy lung growth

In the adult rodent, pneumonectomy results in compensatory lung growth characterized by cell proliferation. The molecular mechanisms governing this response remain unknown. We hypothesized that, in the early period postpneumonectomy, upregulated expression of transcription factors drives the growth process. We utilized a cDNA expression array to screen for upregulated transcription factors after left pneumonectomy in adult C57BL/6 mice, using unoperated mice as controls. Quantification of mRNA expression in the remaining lung at 2 h demonstrated a twofold or greater upregulation of six transcription factors: early growth response gene-1 (Egr-1), Nurr77, tristetraprolin, the primary inhibitor of nuclear factor-kappa B (I kappa B-alpha), gut-enriched Krüppel-like factor (GKLF), and LRG-21. Northern analysis was used to quantify the upregulation of expression of these genes relative to sham thoracotomy and unoperated controls. The largest increase was in Egr-1 (4.7-fold > naive). Time-course analysis over the first 24 h confirmed the transient nature of the early upregulation. In the context that postpneumonectomy lung growth is associated with cell proliferation and that genes such as Egr-1, Nurr77, LRG-21, and tristetraprolin have known roles in stress response, vascular biology, embryology, and cellular development, these data support the concept that transcription factors function early in the cascade of events leading to the compensatory response.

Downregulation of CXCR4 gene expression in primary human endothelial cells following infection with E1(-)E4(+) adenovirus gene transfer vectors

Infection of human endothelial cells with first-generation E1(-)E4(+) adenovirus (Ad) vectors leads to prolonged cell survival and changes in the cell phenotype to a more quiescent stage. Based on the concept that the CXCR4, the receptor for the endothelial chemoattractant stromal-derived factor-&alpha (SDF-alpha), is constitutively expressed by quiescent, resting endothelial cells, the present study analyzes the effect of Ad vector infection on CXCR4 expression and SDF-alpha responses of human umbilical vein endothelial cells (HUVEC). CXCR4 transcripts were markedly downregulated in E1(-)E4(+) Ad-infected cells 48 h following infection, but not in uninfected control cells or when the cells were infected with an E1(-)E4(-) Ad vector. Analysis of surface CXCR4 expression by flow cytometry demonstrated marked reduction of the CXCR4 receptor on cells infected with E1(-)E4(+) Ad compared to uninfected control cells or E1(-)E4(-) Ad-infected cells. Infection of other cell types which express CXCR4, such as dendritic cells and myeloma cells, did not exhibit CXCR4 receptor downregulation following infection with E1(-)E4(+) Ad. Consistent with the observed downregulation of CXCR4 mRNA and surface protein, infection of the endothelial cells with an E1(-)E4(+) Ad rendered the cells unresponsive to the chemoattractant SDF-alpha compared to naive or E1(-)E4(-) Ad-infected cells. Together, the data suggest that first-generation Ad vectors, likely the E4 region, modify the ability of endothelial cells to respond to at least one important chemoattractant.

Induction of endogenous genes following infection of human endothelial cells with an E1(-) E4(+) adenovirus gene transfer vector

Recombinant adenovirus (Ad) gene transfer vectors are effective at transferring exogenous genes to a variety of cells and tissue types both in vitro and in vivo. However, in the process of gene transfer, the Ad vectors induce the expression of target cell genes, some of which may modify the function of the target cell and/or alter the local milieu. To develop a broader understanding of Ad vector-mediated induction of endogenous gene expression, genes induced by first-generation E1(-) E4(+) Ad vectors in primary human umbilical vein endothelial cells were identified by cDNA subtraction cloning. The identified cDNAs included signaling molecules (lymphoid blast crisis [LBC], guanine nucleotide binding protein alpha type S [Galpha-S], and mitogen kinase [MEK5]), calcium-regulated/cytoskeletal proteins (calpactin p11 and p36 subunits, vinculin, and spinocerebellar ataxia [SCA1]), growth factors (insulin-like growth factor binding protein 4 and transforming growth factor beta2), glyceraldehyde-6-phosphate dehydrogenase, an expressed sequence tag, and a novel cDNA showing homology to a LIM domain sequence. Two- to sevenfold induction of the endogenous gene expression was observed at 24 h postinfection, and induction continued up to 72 h, although the timing of gene expression varied among the identified genes. In contrast to that observed in endothelial cells, the Ad vector-mediated induction of gene expression was not found following Ad vector infection of primary human dermal fibroblasts or human alveolar macrophages. Empty Ad capsids did not induce endogenous gene expression in endothelial cells. Interestingly, additional deletion of the E4 gene obviated the upregulation of genes in endothelial cells by the E1(-) E3(-) Ad vector, suggesting that genes carried by the E4 region play a central role in modifying target cell gene expression. These findings are consistent with the notion that efficient transfer of exogenous genes to endothelial cells by first-generation Ad vectors comes with the price that these vectors also induce the expression of a variety of cellular genes.

Airway epithelial CFTR mRNA expression in cystic fibrosis patients after repetitive administration of a recombinant adenovirus

We sought to evaluate the ability of an E1(-), E3(-) adenovirus (Ad) vector (Ad(GV)CFTR.10) to transfer the normal human cystic fibrosis transmembrane conductance regulator (CFTR) cDNA to the airway epithelium of individuals with cystic fibrosis (CF). We administered Ad(GV)CFTR.10 at doses of 3 x 10(6) to 2 x 10(9) plaque-forming units over 9 months by endobronchial spray to 7 pairs of individuals with CF. Each 3-month cycle, we measured vector-derived versus endogenous CFTR mRNA in airway epithelial cells prior to therapy, as well as 3 and 30 days after therapy. The data demonstrate that (a) this strategy appears to be safe; (b) after the first administration, vector-derived CFTR cDNA expression in the CF airway epithelium is dose-dependent, with greater than 5% endogenous CFTR mRNA levels at the higher vector doses; (c) expression is transient, lasting less than 30 days; (d) expression can be achieved with a second administration, but only at intermediate doses, and no expression is observed with the third administration; and (e) the progressive lack of expression with repetitive administration does not closely correlate with induction of systemic anti-Ad neutralizing antibodies. The major advantage of an Ad vector is that it can deliver sufficient levels of CFTR cDNA to the airway epithelium so that CFTR expression protects the lungs from the respiratory manifestations of CF. However, this impressive level of expression is linked to the challenging fact that expression is limited in time. Although this can be initially overcome by repetitive administration, unknown mechanisms eventually limit this strategy, and further repetitive administration does not lead to repetitive expression.

E1(-)E4(+) adenoviral gene transfer vectors function as a "pro-life" signal to promote survival of primary human endothelial cells

Although endothelial cells are quiescent and long-lived in vivo, when they are removed from blood vessels and cultured in vitro they die within days to weeks. In studies of the interaction of E1(-)E4(+) replication-deficient adenovirus (Ad) vectors and human endothelium, the cells remained quiescent and were viable for prolonged periods. Evaluation of these cultures showed that E1(-)E4(+) Ad vectors provide an "antiapoptotic" signal that, in association with an increase in the ratio of Bcl2 to Bax levels, induces the endothelial cells to enter a state of "suspended animation," remaining viable for at least 30 days, even in the absence of serum and growth factors. Although the mechanisms initiating these events are unclear, the antiapoptoic signal requires the presence of E4 genes in the vector genome, suggesting that one or more E4 open reading frames of subgroup C Ad initiate a "pro-life" program that modifies cultured endothelial cells to survive for prolonged periods.

Modification of the genetic program of human alveolar macrophages by adenovirus vectors in vitro is feasible but inefficient, limited in part by the low level of expression of the coxsackie/adenovirus receptor

Robust expression of genes transferred by adenovirus (Ad) vectors depends upon efficient entry of vectors into target cells. Cells deficient in the coxsackie/adenovirus receptor (CAR) are difficult targets for Ad-mediated gene transfer. We hypothesized that low levels of CAR expression may be responsible, in part, for the relative inefficiency of Ad-mediated gene transfer to human alveolar macrophages (AMs). CAR gene expression was detected in human AMs by reverse transcription-polymerase chain reaction and at low levels by Northern analysis. Indirect immunofluorescence showed specific, low-intensity surface staining for CAR, but at levels below those found on the positive-control A549 human lung epithelial cell line. Consistent with this, AMs expressed Ad vector transgenes 100 to 1,000-fold less efficiently than A549 cells, as assessed using the beta-galactosidase reporter (chemiluminescence assay) and green fluorescent protein (fluorescence microscopy and flow cytometry). At high multiplicity of infection, AMs from an HIV+ individual could be transduced with an AdIFNgamma vector to secrete detectable human interferon-gamma. Ad transgene expression by AMs was blocked by capsid fiber protein, suggesting that CAR is required in the pathway for productive Ad entry into alveolar macrophages. To confirm that Ad transgene expression by AMs is limited by low levels of CAR expression, cells were infected with an Ad vector containing the CAR complementary DNA (cDNA). Enhanced expression of CAR protein was demonstrated by indirect immunofluorescence, and the CAR cDNA-transduced cells showed 5-fold enhancement of subsequent Ad transgene expression. These observations demonstrate that human AMs can be targets for Ad-mediated gene transfer, but that efficiency of transgene expression is limited, at least in part, by low levels of CAR expression.

Pseudocyst of the auricle-a new method of treatment

Pseudocyst of the auricle is a rare condition and is hardly encountered in routine ENT practice. There have been only about 200 of these cases reported in world literature. The etiology remains obscure and the treatment modalities uncertain. The authors present their series of 15 cases and review the available literature on this condition. A new and completely successful method of treatment is also presented.

Characterization of the Dictyostelium discoideum cellulose-binding protein CelB and regulation of gene expression

Similar to other stages of Dictyostelium development, spore germination is a particularly suitable model for studying regulation of gene expression. The transition from spore to amoeba is accompanied by developmentally regulated changes in both protein and mRNA synthesis. A number of spore germination-specific cDNAs have been isolated previously. Among these are two members of the 270 gene family, a group of four genes defined by the presence of a common tetrapeptide repeat of Thr-Glu-Thr-Pro. celA (formerly called 270-6) and celB (formerly 270-11) are expressed solely and coordinately during spore germination, the levels of the respective mRNAs being low in dormant spores, rising during germination to a maximum level at about 2 h, and then rapidly declining as amoebae are released from spores. The mRNAs are not found in growing cells or during multicellular development. The rapidity with which these transcripts accumulate and then disappear during germination implies that the respective products may be important for the process. We reported previously that the CelA protein is a cellulase (endo-1, 4-beta-glucanase (EC 3.2.1.4)). In the present investigation, properties of the CelB protein, a glycosylated protein of 532 amino acids, 36% of which are serine or threonine, were examined, and the upstream sequences involved in the developmental regulation of the expression of the gene have been determined. The CelB protein does not demonstrate cellulase activity, but it has a cellulose-binding domain. Its role, if any, in degradation of the cellulose-containing spore wall is unknown. To identify cis-acting elements in the celB promoter, unidirectional 5' deletions of the celB upstream noncoding region were constructed and used to transform amoebae. Analysis of promoter activity during different stages of development shows that a short, very A/T-rich sequence of approximately 81 base pairs is sufficient for spore-specific celB transcription. Contained in this sequence is the Myb oncogene protein binding site, TAACTG, which was shown previously to be a negative regulator of celA transcription. Dictyostelium and mouse Myb proteins bind to this region of the promoter, suggesting that Myb might regulate celB gene expression negatively as it does in celA.

HIV-1 Vpr suppresses immune activation and apoptosis through regulation of nuclear factor kappa B

The HIV-1 accessory gene product Vpr can influence viral pathogenesis by affecting viral replication as well as host cell transcription and proliferation. We have investigated the effects of Vpr on host cell activation and confirm that it influences cellular proliferation. However, we have also found that Vpr modulates T-cell receptor (TCR)-triggered apoptosis in a manner similar to that of glucocorticoids. In the absence of TCR-mediated activation, Vpr induces apoptosis whereas in its presence, Vpr interrupts the expected induction of apoptosis. This regulation of apoptosis is linked to Vpr suppression of NF-kappa B activity via the induction of I kappa B, an inhibitor of NF-kappa B. Further, Vpr suppresses expression of IL-2, IL-10, IL-12, TNF alpha and IL-4, all of which are NF-kappa B-dependent. The effects of Vpr could be reversed by RU486. Our finding that Vpr can regulate NF-kappa B supports the hypothesis that some aspects of viral pathogenesis are the consequence of cell dysregulation by Vpr.

Genetics of otosclerosis

Otosclerosis is an early-middle adult life genetic disease affecting bone remodelling in the ear. Current knowledge of otosclerosis as an inherited disease dates to the mid-19th century, and we report here an attempt to understand the genetics of otosclerosis and detect its heterogeneity. The analysis was conducted on 151 otosclerotic families. The results of our study indicate that while heredity plays an important role in the manifestation of the disease a substantial portion of otosclerotic cases could arise due to non-genetic causes.

AT-rich upstream sequence elements regulate spore germination-specific expression of the Dictyostelium discoideum celA gene

Two members of a family of spore germination-specific cDNAs, celA and celB, are expressed coordinately, exclusively during spore germination. In the present study the regulatory sequence elements responsible for celA germination-specific expression have been identified. The very AT-rich 81 bp sequence between -664 and -584 upstream of the translation initiation site was required for proper temporal transcription of the celA gene. This sequence is comprised of two cis elements, each of which was active by itself in allowing celA expression. Electrophoretic mobility shift assays showed that a factor(s) in an extract prepared from germinating spores bound to the celA regulatory region. One of the three complexes formed was specific for the germinating spore extract. The results are consistent with the notion that the factor(s) that binds to this regulatory region is involved in expression of celA.

Cloning and functional expression of a Dictyostelium discoideum protein tyrosine phosphatase

Using polymerase chain reaction methods, we cloned a 1.7-kilobase cDNA, denoted DdPTPa, that has high homology with other known eukaryotic protein tyrosine phosphatases. DdPTPa possess a 241-amino acid protein tyrosine phosphatase domain located in the C terminus, which exhibits a 39-43% amino acid sequence identity with published protein tyrosine phosphatases. Absence of a characteristic signal sequence and transmembrane domain suggests that DdPTPa is a nonreceptor type cytoplasmic protein tyrosine phosphatase. Southern blot analysis of genomic DNA indicates the presence of a multigene protein tyrosine phosphatase family in Dictyostelium. Northern blot analysis reveals four species of mRNA that hybridize to the DdPTPa probe, at least three of which are developmentally regulated. The entire coding sequence of DdPTPa was subcloned into the pET15-b vector and expressed in Escherichia coli. Affinity-purified DdPTPa protein efficiently dephosphorylates both p-nitrophenyl phosphate and tyrosine-phosphorylated reduced, carboxyamidomethylated, and maleylated lysozyme. A Dictyostelium transformant overexpressing DdPTPa does not develop normally. The overexpresser fails to aggregate, in contrast to the control transformant containing vector alone, and after 24 h gives rise to only a few abnormal slugs and small fruiting bodies.

The Dictyostelium discoideum spore germination-specific cellulase is organized into functional domains

During Dictyostelium discoideum spore germination, degradation of the cellulose-containing spore wall is required to allow the amoeba to emerge. The CelA gene, which is transcribed and expressed exclusively during spore germination, codes for a 705-amino-acid protein that has cellulase activity [endo-(1,4)-beta-D-glucanase]. Amoebae transformed by a vector containing the CelA coding sequence or portions of it transcribed from a heterologous promoter expressed and secreted full-length or suitably truncated proteins during vegetative growth when, under normal conditions, these proteins are not made. The gene constructs divided the CelA protein into three domains: a 461-amino-acid N-terminal region that has significant similarity to those of other cellulases and that has been shown to be the catalytic domain; a contiguous 91-residue repeat containing the motif threonine-glutamic acid-threonine-proline, which is glycosylated; and, joined to the repeat, a C-terminal 153-amino-acid sequence that most probably defines a cellulose-binding domain.