Visceral leishmaniasis control in Thi Qar Governorate, Iraq, 2003

Since 1991, visceral leishmaniasis has extended to new areas rarely affected before in Iraq, such as the southern governorates. In 2003, in the aftermath of the invasion of the Coalition Forces, Thi Qar Governorate was at high risk for an outbreak of visceral leishmaniasis. This paper describes the cooperation of an international nongovernmental organization and a district primary health care department to restore the visceral leishmaniasis control programme in Thi Qar in 2003 and prevent a major outbreak of visceral leishmaniasis. It also discusses the lessons learned and presents recommendations for the future.

Practice parameter: treatment of postherpetic neuralgia: an evidence-based report of the Quality Standards Subcommittee of the American Academy of Neurology

A systematic review of the literature on postherpetic neuralgia was performed. The authors identified studies using the National Library of Medicine's Medline database and Cochrane Library database. The authors determined absolute reduction rate, number needed to treat (NNT), 95% CI for NNT, and number needed to harm (NNH) for successful therapies of postherpetic neuralgia. Tricyclic antidepressants, gabapentin, pregabalin, opioids, and lidocaine patch were found to be effective in reducing the pain of postherpetic neuralgia.

Prevention of hepatitis B virus recurrence after living donor liver transplantation

The emergence of lamivudine-resistant hepatitis B mutations is a major complication during pretransplantation treatment. The proper time to begin Lamivudine before transplantation is not yet known. Twenty-six patients received preoperative lamivudine treatment followed by combined lamivudine and hepatitis B immunoglobulin after transplantation up to December 2002. The length of preoperative lamivudine treatment ranged from 13 to 200 days (mean, 52 +/- 37 days). Hepatitis B virus-DNA was positive in 22 of 26 (84.6%) patients before preoperative lamivudine prophylaxis and persistently positive among only 4 of 22 patients (18%) who at transplantation did not show a viral mutation. In all patients, hepatitis B virus-DNA became negative immediately after transplantation. At a median follow-up of 34 months, neither a hepatitis B recurrence nor a mutation had occurred in any patient. The ability to schedule the proper time for preoperative lamivudine prophylaxis is an advantage of living donor liver transplantation.

Immunogenicity, safety, and memory of different schedules of Neisseria meningitidis A/C-diphtheria toxoid conjugate vaccine in infants in Niger

We studied one to four doses of meningococcal polysaccharides A and C conjugated to diphtheria toxoid (Men D) versus A/C polysaccharide (Men PS) vaccine in 618 infants in Niger. Men PS at 24 months permitted evaluating memory. Two Men D doses (at 3 and 9 months) induced higher serum bactericidal activity (SBA) than other regimens. SBA titers after Men PS at 24 months were higher in those given Men D in infancy versus Men PS. While responses were lower for serogroup C, hyporesponsiveness was not evident. Men D was well-tolerated. A single Men D dose in infancy appeared to induce memory.

The mechanisms of Ni2+ ions sorption by AlPO4

Sorption of Ni2+ ions by AlPO4 is studied as a function of concentrations and temperature at pH 7. Potentiometric titration, dissolution and FTIR studies are employed to determine the mechanism of the process of the uptake of Ni2+ ions which is found to be both the ion exchange and the surface precipitation of the corresponding metal phosphates. Freundlich equation is found applicable to the sorption data, and is employed to evaluate the thermodynamic parameters deltaH(o) and deltatS(o).

Evaluation of selected Sudanese medicinal plants for their in vitro activity against hemoflagellates, selected bacteria, HIV-1-RT and tyrosine kinase inhibitory, and for cytotoxicity

Ethnobotanical investigations led to the selection of 19 plant species, used traditionally in Sudan against malaria and other similar tropical diseases, for further studies. Pamianthe peruviana (Amaryllidaceae) exhibited significant activity against a chloroquine-resistant Plasmodium falciparum strain (K1) and a chloroquine-sensitive strain (NF54) with IC(50) values of 0.6 and 1.1 microg/ml, respectively. Additionally, P. peruviana showed considerable activities against Trypanosoma brucei rhodesiense (IC(50) 1.5 microg/ml) and T. cruzi (IC(50) 11.8 microg/ml). The antiplasmodial activity of the different extracts of Salvadora persica (Salvadoraceae) against P. falciparum NF54 strain were found to be 0.6 microg/ml (stems) and 0.7 microg/ml (leaves). Extracts of different parts of Combretum hartmannianum (Combretaceae) possessed significant activity against the chloroquine-sensitive P. falciparum strain (NF54) with IC(50) values of 0.2 microg/ml (bark), 0.4 microg/ml (stem) and 4.3 microg/ml (leaves). Most interestingly, the extracts of the leaves of C. hartmannianum totally inhibited the enzyme HIV-1 reverse transcriptase (HIV-1 RT) at a concentration of 66 microg/ml. A comparably strong activity against p56(lck) tyrosine kinase was also seen for this extract.

Correlation of ultrasonographic findings with ultrasound guided fine needle aspiration of liver lesion

Ultrasonographic findings of liver were correlated with cytological findings in a series of 50 patients. Multiple lesions described by ultrasonography and suggested as HCC/TB were proved to be metastatic in 60% cases and hepatocellular carcinoma in 40% cases by cytological examination. Multiple lesions suggested as metastatic lesions in ultrasonography was proved as such by cytology in 83% cases. Solitary lesion suggested as neoplastic in ultrasonography was proved as such in cytology in 90% cases. Of the 2 patients suggested as diffuse parenchymal lesion revealed cytological findings of cirrhosis in one case and that of TB in other. Serum alpha-feto protein and Carcinoembryogenic antigen (CEA) was done in all the cases. Serum alpha-feto protein was higher in hepatocellular carcinoma and CEA was higher in metastatic lesions. Ultrasound guided fine needle aspiration of liver can play more role in diagnosis and classification of liver disease than ultrasonographic comment alone, as it requires greater degree of precision to reach diagnostic accuracy.

Cutting edge: Differential regulation of chemoattractant receptor-induced degranulation and chemokine production by receptor phosphorylation

Phosphorylation of G protein-coupled receptors and the subsequent recruitment of beta-arrestin play an important role in desensitization of receptor-mediated responses, including degranulation in leukocytes. In this study, we report that receptor phosphorylation also provides a stimulatory signal for CCR ligand 2 (CCL2) production. C3a stimulated degranulation in a basophilic leukemia RBL-2H3 cell expressing wild-type C3aR or a phosphorylation-deficient mutant (DeltaST-C3aR). In contrast, C3a caused CCL2 production only in C3aR but not DeltaST-C3aR cells. Furthermore, overexpression of G protein-coupled receptor kinase 2 resulted in enhancement of both ligand-induced receptor phosphorylation and CCL2 production but inhibition of degranulation. Agonist activation of C3aR, but not DeltaST-C3aR, led to the translocation of green fluorescent protein tagged beta-arrestin 2 from the cytoplasm to the plasma membrane. These data demonstrate that receptor phosphorylation, which provides a turn off signal for degranulation, is essential for CCL2 production.

The spatial and temporal expression of calretinin in developing rat molars (Rattus norvegicus)

Calretinin is a 29-kDa calcium-binding protein abundantly expressed in central and peripheral neural tissues. The aim here was to determine its expression during various stages of odontogenesis. Five categories of embryonic (E) and postnatal (P) rats at various ages (E17, E18, E20, P0, and P7), both male and female, were used to represent the various stages of molar tooth development. The heads of the experimental animals were harvested at the appropriate time and each was cut mid-sagittally and coronally to locate the tooth germs. Selected sections were stained immunohistochemically with polyclonal rabbit anticalretinin at a concentration of 1:25 after microwave irradiation. The results showed that calretinin is distributed widely in epithelium-derived tissues during odontogenesis in rat molar tooth germs. It was expressed focally in the dental lamina, outer enamel epithelium, stellate reticulum and stratum intermedium at different stages. In contrast, it was expressed diffusely and intensely in the inner enamel epithelium and presecretory ameloblasts, although it was discontinuous over the cusp tips. In the secretory ameloblasts, the staining was less intense, being restricted to the cytoplasm, including Tomes' processes. This distribution suggests that calretinin may play a part in enamel formation.

Distribution of alpha glutathione S-transferase in ovarian neoplasms: an immunohistochemical study

AIMS

Alpha glutathione S-transferase (alpha-GST) has been shown to be an immunohistochemical marker for delta(4-5) isomerase, an enzyme active in steroidogenesis. The purpose of this study was to document the distribution of alpha-GST in ovarian neoplasms in order to evaluate its usefulness as a diagnostic tool.

METHODS AND RESULTS

A total of 92 tumours (25 sex cord/stromal, 53 epithelial and 14 germ cell) were subjected to immunohistochemistry using a commercially available polyclonal antibody to alpha-GST. The avidin-biotin complex was used as a detection system. Positive staining was found in luteinized stromal cells of all tumour types (58/92). This included the Leydig cells of Sertoli-Leydig cell tumours (7/7) and was particularly prominent in the stromal cells of both benign and malignant mucinous tumours (24/25). Granulosa and Sertoli cells showed weak or no intracytoplasmic staining, which is expected because they do not normally produce androstenedione. They did show some intranuclear staining. Malignant mucinous (12/25) and occasional other epithelial tumours showed focal intracytoplasmic positive staining. Yolk sac tumours showed focal positivity (7/8).

CONCLUSIONS

Intracytoplasmic staining of stromal cells is considered to indicate steroidogenesis and intranuclear staining the intracytoplasmic transport function of alpha-GST. The intracytoplasmic staining of mucinous carcinomas might represent an up-regulation of some detoxification function. The findings suggest that antibody to alpha-GST has some value in the investigation of ovarian pathology and could readily be included in any panel of antibodies used to investigate ovarian neoplasms of uncertain histogenesis.

[Male pseudo-hermaphroditism due to partial 5 alpha-reductase deficiency, a case report]

Male pseudo hermaphroditism caused by steroid 5 alpha reductase deficiency is a rare autosomal recessive disorder. This enzyme catalyses the conversion of testosterone to dihydrotestosterone (DHT) in genital tissue. The potent androgen DHT is required for full masculinization of the external genitalia hence, masculinization defects of varying degree result from diminished DHT formation. We report a Tunisian patient who was raised as a girl, presented to us at the age of 15, because male phenotype had become predominant at puberty. Endocrinological investigations revealed an in crease in the ratio serum testosterone/DHT = 17. Treatment with dihydrotestosterone and surgical correction, after psychological evaluation permitted the change of gender identity to male.

Use of calretinin in the differential diagnosis of unicystic ameloblastomas

AIMS

Calretinin, a 29-kDa calcium-binding protein is expressed widely in normal human tissues and tumours including both unicystic and solid and multicystic ameloblastomas. The histological distinction between unicystic ameloblastomas and certain non-neoplastic odontogenic cysts can be problematic. The objective of this study was to determine whether calretinin was expressed in the lining epithelium of odontogenic keratocysts, residual and dentigerous cysts and to determine whether this calcium-binding protein could be used to distinguish these cysts from the unicystic ameloblastoma.

METHODS AND RESULTS

The lining epithelium in 22 cases of odontogenic keratocyst, 26 cases of residual cyst and 20 cases of dentigerous cyst were examined for the expression of calretinin. No positive epithelial staining was observed in any of these cystic lesions. In comparison, however, 81.5% of cases of unicystic ameloblastoma showed a coarse dark brown staining of the more superficial epithelial cell layers. Scattered positive stromal and epithelial cells were present; these were interpreted as mast cells.

CONCLUSIONS

Calretinin appears to be a specific immunohistochemical marker for neoplastic ameloblastic epithelium and we suggest that it may be an important diagnostic aid in the differential diagnosis of cystic odontogenic lesions and ameloblastic tumours.

Clinical comparison of frequency doubling technology perimetry and Humphrey perimetry

AIM

To determine the number of missed points on frequency doubling technology (FDT) perimetry that optimise the sensitivity and specificity of the test and to determine the topographical accuracy of the test in a clinical setting.

METHODS

In a prospective study, the perimetric data from 99 patients who underwent both FDT perimetry in the screening mode and Humphrey 24-2 (H24-2) were used to determine the sensitivity and specificity of the FDT perimetry compared with the full threshold H24-2 as the gold standard.

RESULTS

Missed points on the FDT perimetry correlated with both the mean deviation and the corrected pattern standard deviation on the Humphrey perimetry. A score assigned to abnormal points on the FDT perimetry and the Humphrey total deviation plot showed a significant correlation for both the location and the depth of the defect. In comparing the Humphrey hemifield test with the FDT perimetry results, if at least one missed point on the frequency doubling test was considered as abnormal then the overall sensitivity of the test was 78.1% and the specificity was 89.1%.

CONCLUSION

FDT perimetry in the screening mode performed in a clinical setting was highly specific, exhibited reasonable sensitivity, and accurately determined the location and depth of scotomas when compared with the full threshold Humphrey 24-2.

Chemokine production by G protein-coupled receptor activation in a human mast cell line: roles of extracellular signal-regulated kinase and NFAT

Chemoattractants are thought to be the first mediators generated at sites of bacterial infection. We hypothesized that signaling through G protein-coupled chemoattractant receptors may stimulate cytokine production. To test this hypothesis, a human mast cell line (HMC-1) that normally expresses receptors for complement components C3a and C5a at low levels was stably transfected to express physiologic levels of fMLP receptors. We found that fMLP, but not C3a or C5a, induced macrophage inflammatory protein (MIP)-1ss (CCL4) and monocyte chemoattractant protein-1 (CCL2) mRNA and protein. Although fMLP stimulated both sustained Ca(2+) mobilization and phosphorylation of extracellular signal-regulated kinase (ERK), these responses to C3a or C5a were transient. However, transient expression of C3a receptors in HMC-1 cells rendered the cells responsive to C3a for sustained Ca(2+) mobilization and MIP-1ss production. The fMLP-induced chemokine production was blocked by pertussis toxin, PD98059, and cyclosporin A, which respectively inhibit G(i)alpha activation, mitgen-activated protein kinase kinase-mediated ERK phosphorylation, and calcineurin-mediated activation of NFAT. Furthermore, fMLP, but not C5a, stimulated NFAT activation in HMC-1 cells. These data indicate that chemoattractant receptors induce chemokine production in HMC-1 cells with a selectivity that depends on the level of receptor expression, the length of their signaling time, and the synergistic interaction of multiple signaling pathways, including extracellular signal-regulated kinase phosphorylation, sustained Ca(2+) mobilization and NFAT activation.

Endothelin receptor expression in colorectal cancer

The distribution of endothelin-A- and B- (ET(A), ET(B)) receptor subtypes was compared in colorectal cancer to that in normal colon and their expression in the colorectal cancer cell lines LIM1215. HT29, SKCO1, SKCO17 and LoVo was determined, using gross and high resolution autoradiography and quantified by densitometry. ET(A) and ET(B) binding sites were expressed by all the cell lines. There was significantly (p = 0.008) higher expression of ET(A)-receptors by cancers (205.95 dpm x 1000/mm2) compared normal colon (129.19 dpm x 1000/mm2). However, for ET(B)-receptors, this was reversed, with significantly (p = 0.008) higher expression of ET(B) binding in normal colon (207.00 dpm x 1000/mm2) than in tumours (122.35 dpm x 1000/mm2).

Stimulation of colorectal cancer cell line growth by ET-1 and its inhibition by ET(A) antagonists

BACKGROUND

The vasoactive peptide endothelin 1 (ET-1) acts via two receptors, endothelin receptors A (ET(A)) and B (ET(B)). ET-1 is overexpressed by human cancers in vivo and in vitro and may be mitogenic for cancer cells.

METHOD

To elucidate if ET-1 is a growth regulator the following were investigated in human colorectal cancer cell lines (LIM1215 and HT29): ET-1 production by ELISA; ET receptor expression using radioligand autoradiographic techniques; and responsiveness to ET-1, and to ET(A) and ET(B) antagonism by growth measurements.

RESULTS

ET-1 was produced by LIM1215 and HT29 cells (21.3 and 41.7 fmol/ml/10(6) cells (24 hours); 22.6 and 71.7 fmol/ml/10(6) cells (48 hours), respectively). ET(A) and ET(B) receptors were expressed by both cell lines. Addition of ET-1 resulted in a dose dependent increase in cell numbers which was significant at 10(-8)-10(-9) M for LIM1215, with the greatest increase at 10(-8) M (32.7% and 28.4% increase above controls at 48 hours and 72 hours; p<0.05) and at 10(-8)-10(-9) M for HT29, with the greatest increase at 10(-9) M (13.4% and 15.7% increase above controls at 48 hours and 72 hours; p<0.05). ET(A) antagonists BQ123 and BQ610, but not the ET(B) antagonist BQ788, inhibited ET-1 induced proliferation of both LIM1215 and HT29 (p<0.05).

CONCLUSION

ET-1 can stimulate the proliferation of colorectal cancer cell lines via the ET(A), but not the ET(B), receptor.

Caged chemotactic peptides

This work has as its ultimate goal the creation of a concentration spike of a chemoattractant peptide in a time-resolved and spatially defined way using a light pulse. This strategy requires "caging" the peptide with a photochemically removable group. Model studies used alanine ethyl ester in reductive amination with nitrobenzaldehydes to form two different N-nitrobenzyl derivatives. An fMLF peptide bearing these two N-terminal nitrobenzyl groups was also prepared. The yield and kinetics of their deprotection to return the fMLF peptide were determined. It was established that the caged peptides have vastly reduced biological activity as chemoattractants, as designed.

Scintimammography with 11beta-methoxy-(17alpha,20Z)-[123I]iodovinylestrad iol: a complementary role to 99mTc-methoxyisobutyl isonitrile in the characterization of breast tumors

The aim of this study was to investigate a possible relationship between 99mTc-methoxyisobutyl isonitrile (MIBI) uptake and the estrogen receptor (ER) status of breast tumors as determined by 11beta-methoxy-(17alpha,20Z)-[123I]iodovinylestradi ol (MIVE) scintimammography.

METHODS

Thirteen patients referred for MIVE scintimammography after abnormal mammography or finding of a suspect mass on physical examination were injected intravenously with MIVE. Planar images of the breasts and axillary region were taken with both radiopharmaceuticals and compared with pathologic examination of the tumor tissue and in vitro ER quantification.

RESULTS

The presence of cancerous tissue, as indicated by MIBI uptake, is a prerequisite for the accumulation of MIVE by the breast tumors. There was no statistically significant correlation between the MIBI and MIVE tumor uptake ratios. However, the latter correlate well with the presence of ER, as determined by an in vitro assay.

CONCLUSION

MIVE scans add unique information concerning the tumor ER status in breast cancer patients, which could contribute to a better characterization of the tumor and aid in the selection of the most appropriate treatment protocol.

Chemotherapy in advanced nasopharyngeal cancer

Chemotherapy is an integral part of treatment for patients with nasopharyngeal carcinoma. Chemotherapy can achieve long-term survival rates of up to 15% to 20%, even in patients with recurrent or metastatic disease. In the majority of studies reported, patients with previously untreated locally advanced stage III and IV nasopharyngeal carcinoma showed improved local control, decreased systemic metastasis, and improved disease-free and overall survival when treated with cisplatin (Platinol)-based combination chemotherapy in conjunction with radiotherapy. In prospective, randomized, phase III trials, concurrent chemoradiotherapy, followed by adjuvant chemotherapy, significantly improved local control, systemic control, and progression-free and overall survival. The authors believe that different sequences of treatment modalities and newer chemotherapy agents need to be investigated in the future.

Identification of a region at the N-terminus of phospholipase C-beta 3 that interacts with G protein beta gamma subunits

Members of the phospholipase C-beta (PLC-beta) family of proteins are activated either by G alpha or G beta gamma subunits of heterotrimeric G proteins. To define specific regions of PLC-beta 3 that are involved in binding and activation by G beta gamma, a series of fragments of PLC-beta 3 as glutathione-S-transferase (GST) fusion proteins were produced. A fragment encompassing the N-terminal pleckstrin homology (PH) domain and downstream sequence (GST-N) bound to G protein beta 1 gamma 2 in an in vitro binding assay, and binding was inhibited by G protein alpha subunit, G alpha i1. This PLC-beta 3 fragment also inhibited G beta gamma-stimulated PLC-beta activity in a reconstitution system, while having no significant effect on G alpha q-stimulated PLC-beta 3 activity. The N-terminal G beta gamma binding region was delineated further to the first 180 amino acids, and the sequence Asn150-Ser180, just distal to the PH domain, was found to be required for the interaction. Mutation of basic residues 154Arg, 155Lys, 159Lys, and 161Lys to Glu within this region reduced G beta gamma binding affinity and specifically reduced the EC50 for G beta gamma-dependent activation of the mutant enzyme 3-fold. Basal activity and G alpha q-dependent activation of the enzyme were unaffected by the mutations. While these basic residues may not directly mediate the interaction with G beta gamma, the data provide evidence for an N-terminal G beta gamma binding region of PLC-beta 3 that is involved in activation of the enzyme.

(17alpha,20E/Z)-iodovinyl- and 16alpha-iodP618-homoestradiol derivatives: synthesis and evaluation for estrogen receptor imaging

Three new 125I-radioiodinated estrogens featuring a 13beta-ethyl instead of the natural 13beta-methyl group, i.e. 18-homoestradiols, were synthesized and evaluated as potential estrogen receptor imaging agents. The 16alpha-iodo-18-methylestradiol and the 125I-labeled analog were synthesized from the corresponding 16beta-bromo analog by the halogen-exchange method. The cis-bromohydrin precursor was obtained by bromination of an estrone enolacetate, followed by epimerization and reduction. The isomeric (17alpha,20E/Z)-iodovinyl-18-methylestradiols were prepared via the vinyltin intermediates. Treatment of 18-methyl-17alpha-ethynylestradiol with tri-n-butyltin hydride, in the presence of azobisisobutyronitrile as catalyst and heating at 90-100 degrees C afforded the (17alpha,20E)-tri-n-butylstannyl isomer as the major product. Changing the catalyst for triethyl borane, at room temperature, mainly gave the 20Z-isomer. The nca 125I-labeled analogs were obtained from their corresponding tin intermediates upon treatment with [125I]NaI in the presence of H2O2. The 16alpha-[125I]iodo- and isomeric (17alpha,20E/Z)-[125I]iodovinyl-18-methylestradiols were evaluated for estrogen receptor-mediated uterine uptake in immature female rats. Homologation of the C13-methyl group did improve the uterine uptake of the iodovinyl derivatives, but also increased blood retention, resulting in lower target uptake ratios. In the case of the 16alpha-iodo analog uterine retention decreased upon C13-homologation.

Chemoattractant receptors activate distinct pathways for chemotaxis and secretion. Role of G-protein usage

Human leukocyte chemoattractant receptors activate chemotactic and cytotoxic pathways to varying degrees and also activate different G-proteins depending on the receptor and the cell-type. To determine the relationship between G-protein usage and the biological and biochemical responses activated, receptors for the chemoattractants formyl peptides (FR), platelet-activating factor (PAFR), and leukotriene B(4) (BLTR) were transfected into RBL-2H3 cells. Pertussis toxin (Ptx) served as a Galpha(i) inhibitor. These receptors were chosen to represent the spectrum of G(i) usage as Ptx had differential effects on their ability to induce calcium mobilization, phosphoinositide hydrolysis, and exocytosis with complete inhibition of all responses by FR, intermediate effects on BLTR, and little effect on PAFR. Ptx did not affect ligand-induced phosphorylation of PAFR and BLTR but inhibited phosphorylation of FR. In contrast, chemotaxis to formylmethionylleucylphenylalanine, leukotriene B(4), and platelet-activating factor was completely blocked by Ptx. Wortmannin, a phosphotidylinositol 3-kinase inhibitor, also completely blocked ligand-induced chemotaxis by all receptors but did not affect calcium mobilization or phosphoinositide hydrolysis; however, it partially blocked the exocytosis response to formylmethionylleucylphenylalanine and the platelet-activating factor. Membrane ruffling and pseudopod extension via the BLTR was also completely inhibited by both Ptx and wortmannin. These data suggest that of the chemoattractant receptors studied, G-protein usage varies with FR being totally dependent on G(i), whereas BLTR and PAFR utilize both G(i) and a Ptx-insensitive G-protein. Both Ptx-sensitive and -insensitive G-protein usage can mediate the activation of phospholipase C, mobilization of intracellular calcium, and exocytosis by chemoattractant receptors. Chemotaxis, however, had an absolute requirement for a G(i)-mediated pathway.