Schwannoma of floor of the mouth

Schwannoma is an intraoral rare, benign neoplasm arising from and consisting solely of Schwann cells. Its etiology is unknown. It presents as a solitary, slow growing, smooth surfaced, generally asymptomatic firm mass. Schwannomas commonly occur between 30 and 50 years. It is relatively uncommon, although a quarter of all Schwannoma's occurs in the head and neck region. Schwannoma of the floor of the mouth is rare in the oral region. Described is a case of Schwannoma of the floor of the mouth in a 28-year-old male, of large size.

Cytochrome P450 2C9 gene polymorphism in phenytoin induced gingival enlargement: A case report

Gingival enlargement comprises any clinical condition in which an increase in the size of the gingiva is observed. Among the drugs that induce gingival enlargement, the antiepileptic agent phenytoin has been widely related to this condition. The Cytochrome P450(CYP) superfamily is the most commonly involved enzymes in metabolism of drugs. Common coding region CYP variants that affects drug elimination and response has been studied in great detail. Pharmacogenetic influences on drug metabolism have been widely reviewed and gene polymorphism of cytochrome P450 2C9 appeared to be responsible for much of the interindividual variability on drug elimination. Genetic variation in the CYP2C9 gene can affect metabolism, leading to altered phenotypes. Individuals with poor metaboliser alleles of CYP2C9 gene were shown to have a reduced metabolism of phenytoin compared with wild-type alleles. Thus identification of patients genotype prior to anti-epileptic drug administration could potentially prevent higher serum drug concentrations leading to adverse side effects such as gingival enlargement. This case report addresses the influence of CYP2C9 genetic polymorphism on Phenytoin drug metabolism thereby causing gingival enlargement.

Tuberculosis in haemodialysis patients: A single centre experience

We prospectively followed-up new patients of tuberculosis while on maintenance hemodialysis at a State Government-run tertiary care institute. Between 2000 and 2010, 1237 new patients were initiated on maintainence hemodialysis. The number of patients diagnosed with tuberculosis after initiation of hemodialysis was 131 (10.5% of 1237). The age was 46.4 ± 10.4 (range 8-85) years and there were 90 (68.7%) males. The number of patients diagnosed with tuberculosis on the basis of organ involvement were: Pulmonary-60, pleural effusion-31, lymph node-21, meningitis-8, pericardial effusion-7, peritoneum-2, latent tuberculosis-2. The incidence of tuberculosis in hemodialysis was found to be 105.9 per 1000 patient years. Male gender, diabetes mellitus, past history of tuberculosis, mining as an occupation, low serum albumin, and duration of hemodialysis more than 24 months, and unemployment were found to be significant risk-factors on univariate analysis.

A generalized, non-pruritic variant of lichen amyloidosis: a case report and a brief review

Lichen amyloidosis (LA) has been considered a highly pruritic dermatosis, and the deposition of fibrillar material has generally been considered to be secondary to the scratching. Focal epidermal damage and chronic scratching have been implicated as the pathogenetic factors in the occurrence of LA, although they may not be able to explain the occurrence of a widespread variant of this dermatosis. There are few case reports describing the occurrence of a non-pruritic variant of LA. We hereby report a case of non-pruritic, generalized variant of lichen amyloidosis.

CD4+ Th17 cells discriminate clinical types and constitute a third subset of non Th1, Non Th2 T cells in human leprosy

BACKGROUND

Patients with localized tuberculoid and generalized lepromatous leprosy show respectively Th1 and Th2 cytokine profile. Additionally, other patients in both types of leprosy also show a non discriminating Th0 cytokine profile with both interferon-γ and IL-4. The present study investigated the role of Th17 cells which appear to be a distinct subtype of Th subtypes in 19 tuberculoid and 18 lepromatous leprosy patients. Five healthy subjects with long term exposure to infection and 4 skin biopsies from healthy subjects undergoing cosmetic surgery were used as controls.

METHODOLOGY/PRINCIPLE FINDINGS

An array of Th17 related primers for cytokines, chemokines and transcription factors was used in real time reverse transcribed PCR to evaluate gene expression, ELISA for cytokine secretion in the supernatants of antigen stimulated PBMC cultures and flow cytometry for establishing the phenotype of the IL-17, IL-21 producing cells.

CONCLUSIONS/SIGNIFICANCE

IL-17 isoforms showed significantly higher expression and release in supernatants of antigen stimulated PBMC cultures and dermal lesions of healthy contacts and tuberculoid leprosy as compared to lepromatous leprosy (p<0.003). This was further confirmed by Th17 associated transcription factor RORC, cytokines IL-21, IL-22, and IL-23, chemokines MMP13, CCL20, CCL22. Of interest was the association of IL-23R and not IL-6R with IL-17(+) cells. The Th17 cells were CD4(+) CCR6(+) confirming their effector cell lineage. Polarized Th1 cytokines were seen in 3/7 tuberculoid and Th2 cytokines in 5/10 lepromatous leprosy patients. Of importance was the higher association of Th17 pathway factors with the non-polarized Th0 types as compared to the polarized Th1 and Th2 (p<0.01). Our study draws attention to a third type of effector Th cell that may play a role in leprosy.

mRNA and DNA PCR tests in cutaneous tuberculosis

BACKGROUND

The microbiologic diagnosis of cutaneous tuberculosis is difficult because most lesions harbor only a small number of mycobacteria that cannot usually be detected by staining for the organism or by culture. Nucleic acid amplification tests based on the polymerase chain reaction (PCR) are potentially useful in this situation.

AIMS

To evaluate the utility of mRNA PCR and DNA PCR in the diagnosis of cutaneous tuberculosis.

METHODS

Biopsies from 28 cases of cutaneous tuberculosis and 19 controls with other diseases were subjected to microbiologic tests including direct smears for mycobacteria, culture and both mRNA PCR and DNA PCR. The laboratory was blinded to the clinical diagnosis.

RESULTS

None of the patients or controls showed a positive reaction on mRNA PCR test. Seven of 28 cases and 5 out of 19 controls showed a positive result on DNA PCR test yielding a sensitivity of 25% and a specificity of 73.7%.

CONCLUSION

The results of PCR tests in cutaneous tuberculosis should be interpreted in the light of clinical and histopathological findings.

Rhabdomyolysis induced acute renal failure secondary to statins

Rhabdomyolysis is a syndrome characterized by muscle necrosis and the release of intracellular muscle contents into the systemic circulation. We report a patient with chronic kidney disease who had deterioration of renal function due to combination of risk factors like hypothyroidism and interaction of amlodipine and clopidogrel with statins.

Glomeruloid hemangioma in normal individuals

Glomeruloid hemangioma is a rare, histologically distinctive, cutaneous, benign vascular tumor, originally described by Chan et al. Glomeruloid hemangioma appears specific to polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes syndrome (POEMS), and is usually, but not always, related to Castleman's disease. We herein report two cases with glomeruloid hemangioma, without any features of the POEMS syndrome. Glomeruloid hemangioma requires a high index of suspicion for diagnosis. It could rarely present as a solitary finding, without any evidence of an underlying POEMS syndrome.

Growth, spectroscopic and physicochemical properties of bis mercury ferric chloride tetra thiocyanate: a nonlinear optical crystal

Single crystal of bis mercury ferric chloride tetra thiocyanate [Hg2FeCl3(SCN)4; (MFCTC)] was grown from ethanol-water (3:1) mixed solvent using slow evaporation solvent technique (SEST) for the first time. The cell parameters of the grown crystal were confirmed by single crystal XRD. The coordination of transition metal ions with the SCN ligand is well-identified using FT-IR spectral analysis. The chemical composition of MFCTC was confirmed using CHNS elemental test. The ESR spectral profile of MFCTC was recorded from 298 K to 110K, which strongly suggests the incorporation of Fe(3+) ion and its environment with respect to SCN ligand. The HPLC chromatogram of MFCTC highlights the purity of the compound. The UV-Vis-NIR studies revealed the ultra violet cut-off wavelength of MFCTC in ethanol as 338 nm. The dielectric constant and dielectric loss of the sample were studied as a function of frequency and temperature. The TGA-DTA and DSC thermal analysis show that the sample is thermally stable up to 234.31 °C, which is comparatively far better than the thermal stability of Hg3CdCl2(SCN)6; (171.3 °C) and other metal-organic coordination complex crystals such as CdHg(SCN)4 (198.5 °C), Hg(N2H4CS)4Mn(SCN)4 (199.06 °C) and Hg(N2H4CS)4Zn(SCN)4 (185 °C). The SHG conversion efficiency of MFCTC is found to be higher than KDP.

Oral melanoacanthoma of a rare intraoral site: case report and review of literature

Oral melanoacanthoma is rare pigmented mucosal lesion that presents most commonly on the buccal mucosa, characterized by sudden appearance and rapid radial growth, thus clinically mimicking malignant melanoma. It was originally described as a mixed tumor of melanocytes and keratinocytes, but appears to be a reactive process; formed in areas prone to trauma, and regressing after the removal of trauma or incomplete excision. The clinical appearance of oral melanoacanthoma is nondiagnostic, and biopsy is mandatory to rule out malignancy. We report a case of melanoacanthoma of a rarer oral mucosal site in a 12-year-old Asian male. A brief review of the current literature is also presented.

How to cite this article: Rohilla K, Ramesh V, Balamurali PD, Singh N. Oral Melanoacanthoma of a Rare Intraoral Site: Case Report and Review of Literature. Int J Clin Pediatr Dent 2013;6(1):40-43.

Genital Ulcer Disease: How Worrisome Is It Today? A Status Report from New Delhi, India

Background and Objectives. Genital ulcer diseases represent a diagnostic dilemma, especially in India, where few STI clinics have access to reliable laboratory facility. The changing STI trends require that a correct diagnosis be made in order to institute appropriate treatment and formulate control policies. The objective of this study was to determine recent trends in aetiology of genital ulcers, by using accurate diagnostic tools. Methods. Specimens from 90 ulcer patients were processed for dark field microscopy, stained smears, culture for H. ducreyi, and real-time PCR. Blood samples were collected for serological tests. Results. Prevalence of GUD was 7.45 with mean age at initial sexual experience as 19.2 years. Use of condom with regular and nonregular partners was 19.5% and 42.1%, respectively. Sexual orientation was heterosexual (92.2%) or homosexual (2.2%). There were 8 cases positive for HIV (8.9%). Herpes simplex virus ulcers were the commonest, followed by syphilis and chancroid. There were no cases of donovanosis and LGV. Conclusions. A valuable contribution of this study was in validating clinical and syndromic diagnoses of genital ulcers with an accurate aetiological diagnosis. Such reliable data will aid treatment and better define control measures of common agents and help eliminate diseases amenable to elimination, like donovanosis.

Gene polymorphism in amlodipine induced gingival hyperplasia: a case report

The management of cardiovascular disorders poses a dilemma for the medical fraternity. Calcium channel blockers are one of the most commonly used drugs for the management of this disorder, and it is also a well known fact that they are one of the most common group of drugs responsible for causing gingival over growth as one of their adverse effects. Amlodipine is a new generation hypertensive, which has found wide acceptance and usage due to its duration of action. Even with all its benefits as a potent hypertensive, its effect on gingival tissues is what causes concern to the patient and dental surgeon equally. The objective of this article is to create awareness regarding the adverse oral effects of amlodipine, its underlying mechanism of action in bringing about this adverse reaction, along with providing a brief review of the pharmacologic profile of this drug.

The relevance of mast cells in oral squamous cell carcinoma

CONTEXT

The commonly occurring oral neoplasm - Oral Squamous Cell Carcinoma (OSCC) has an association with the chronic inflammation in the adjacent connective tissue. Mast cells are the local residents of the connective tissue. They are said to be pro inflammatory and immune-amplifying in action and they produce mitogenic cytokines. They exhibit a phenotypic plasticity with a change in the microenvironment, thus making the role of the mast cells in this disease even more intriguing. Mast cells have also been reported to play a role in tumour progression and metastases by promoting angiogenesis.

AIMS

The present study aimed at comparing the Mast Cell Density (MCD) in the Normal Oral Mucosa (NM) and among the various grades of OSCC and at analyzing the possible role of the mast cells.

SETTINGS AND DESIGN

The MCD was assessed by using the 1% Toluidine blue stain in a study sample of 102 cases of different grades of OSCC and in 07 cases of clinically normal oral mucosa.

STATISTICAL ANALYSIS USED

By using the Student's 't' test and one way ANOVA, the Mast Cell Density (MSD) was found to be significantly higher in well differentiated squamous cell carcinoma and in moderately differentiated squamous cell carcinoma as compared to that in the poorly differentiated oral squamous cell carcinoma (P = < 0.01) which was significant at a 1% level. The Spearman's Rank Correlation Co-efficient revealed a significant correlation between the density of the mast cells and the increasing grade of the OSCC.

CONCLUSIONS

These findings denote that as the squamous cell carcinoma enters the poorly differentiated state, there may be some change which is reflected as a decrease in the mast cell density.

Adverse cognitive effects of high-fat diet in a murine model of sleep apnea are mediated by NADPH oxidase activity

Intermittent hypoxia (IH) during sleep, such as occurs in sleep apnea (SA), induces increased NADPH oxidase activation and deficits in hippocampal learning and memory. Similar to IH, high fat-refined carbohydrate diet (HFD), a frequent occurrence in patients with SA, can also induce similar oxidative stress and cognitive deficits under normoxic conditions, suggesting that excessive NADPH oxidase activity may underlie CNS dysfunction in both conditions. The effect of HFD and IH during the light period on two forms of spatial learning in the water maze as well as on markers of oxidative stress was assessed in male mice lacking NADPH oxidase activity (gp91phox⁻/Y) and wild-type littermates fed on HFD. On a standard place training task, gp91phox⁻/Y displayed normal learning, and was protected from the spatial learning deficits observed in wild-type littermates exposed to IH. Moreover, anxiety levels were increased in wild-type mice exposed to HFD and IH as compared to controls, while no changes emerged in gp91phox⁻/Y mice. Additionally, wild-type mice, but not gp91phox⁻/Y mice, had significantly elevated levels of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in hippocampal lysates following IH-HFD exposures. The cognitive deficits of obesity and westernized diets and those of sleep disorders that are characterized by IH during sleep are both mediated, at least in part, by excessive NADPH oxidase activity.

Sjögren-Larsson syndrome: importance of early diagnosis and aggressive physiotherapy

Sjögren-Larsson syndrome (SLS) is a congenital ichthyotic disorder with spasticity. We describe a case of a 5-year-old boy with SLS diagnosed clinically based on congenital ichythosis, quadriplegia, and mental retardation. The child responded well to emollients and antihistamines. His quadriplegia was managed by aggressive physiotherapy and mental retardation by stimulation techniques. After a 3-year follow up, significant improvement was seen in his motor and mental disability. This case highlights the importance of clinical diagnosis and early intervention for such a disabling disorder.

Tinea capitis in the form of concentric rings in an HIV positive adult on antiretroviral treatment

Dermatophyte infection may present in the form of concentric rings caused by Trichophyton concentricum, known as Tinea Imbricata. In immunosuppressed patients, there are reports of lesions in the form of concentric rings caused by dermatophytes other than Trichophyton concentricum too, mostly by Trichophyton tonsurans, known as Tinea indesiciva or Tinea pseudoimbricata. We report a case of tinea capitis in a HIV-positive adult woman on antiretroviral therapy, who presented with concentric rings of papules and pustules with slight scaling on the scalp along with diffuse thinning of hair. Both Potassium hydroxide mount and culture showed the presence of Dermatophytes. Tinea capitis is considered rare in adults, but new cases are being reported in immunocompromised as well as in immunocompetent patients. The pertinent features of this case are: HIV-positive adult female on antiretroviral therapy, presenting with tinea capitis in the form of concentric rings; culture from the lesion grew Microsporum audouinii; responding to oral Terbinafine.

catena-Poly[[bis-(thio-cyanato-κN)cobalt(II)]-di-μ-thio-urea-κ(4)S:S]

In the title polymeric complex, [Co(NCS)(2){SC(NH(2))(2)}(2)](n), the asymmetric unit comprises a Co(II) ion, which is situated on an inversion centre, an N-bound thio-cyanate anion and a μ(2)-bridging thio-urea mol-ecule. The Co(II) atom is coordinated in a distorted octa-hedral fashion within an N(2)S(4) donor set. The bridging thio-urea ligands link Co(II) ions into a polymeric chain extending along [100]. The mol-ecular conformation is stabilized by intra-molecular N-H⋯N hydrogen bonds, which generate S(6) ring motifs. The crystal packing is stabilized by N-H⋯S inter-actions, which connect the chains into a three-dimensional architecture.

Evaluation of the usefulness of Treponema pallidum hemagglutination test in the diagnosis of syphilis in weak reactive Venereal Disease Research Laboratory sera

BACKGROUND AND OBJECTIVES

Biological false positive (BFP) reactivity by the Venereal Disease Research Laboratory (VDRL) test used for diagnosis of syphilis is a cause for concern. The use of the VDRL as a screening procedure is challenged by some studies. The aim of this study is to determine the prevalence of BFP reactions in different subject groups and to assess the usefulness of Treponema pallidum hemagglutination (TPHA) test in low titre VDRL reactive sera.

MATERIALS AND METHODS

A total of 5785 sera from sexually transmitted diseases (STD) clinic attendees, antenatal clinic attendees, husbands of antenatal cases, peripheral health centres attendees (representing community population) and from patients referred from different OPDs/wards were screened for BFP reactions by the VDRL test. Sera reactive in the VDRL test were confirmed by the TPHA test.

RESULTS

Out of 80 qualitative VDRL reactive sera, 68 had <1:8 titre on quantitation and TPHA was positive in 59 samples, indicating BFP reactivity in 0.2% in all the subject groups. BFP was nil in the community population. The male-to-female ratio of BFP reactions was 2:1. VDRL and TPHA positivity was highest (76%) in the age group of 20-29 years. The seroprevalence of syphilis varied from 0.4% to 3.5% in different patient groups.

CONCLUSIONS

The results of this study highlight that the TPHA positivity was high (86.8%) in sera with VDRL titre less than 1:8. Therefore, for the diagnosis of syphilis, it is recommended that a confirmatory test such as TPHA should be performed on all sera with a reactive VDRL regardless of its titre.

Evidence for involvement of Th17 type responses in post kala azar dermal leishmaniasis (PKDL)

Background

Post kala-azar dermal leishmaniasis (PKDL), a dermal sequel of visceral leishmaniasis, caused by Leishmania donovani, constitutes an important reservoir for the parasite. Parallel functioning of counter acting immune responses (Th1/Th2) reflects a complex immunological scenario, suggesting the involvement of additional regulatory molecules in the disease pathogenesis.

Methodology/Principal Findings

In the present study, human cytokine/chemokine/receptor specific cDNA array technique was employed to identify modulations in gene expression of host immuno-determinants during PKDL, followed by evaluation of Th17 type responses by analyzing mRNA and protein expression of Th17 markers (IL-23, IL-17, RORγt) and performing functional assays using Leishmania antigen (TSLA) or recombinant (rec)IL-17. Array analysis identified key immuno-regulatory molecules including cytokines (TNF-α, IFN-γ, IL-10, IL-17), chemokines (MCP-1, MIP-1α), apoptotic molecules (FasL, TRAIL, IRF-1) and receptors (CD40, Fas). Up regulation in lesional expression of Th17 markers was observed during PKDL compared to control (IL-17 and IL-23, P = 0.0008; RORγt, P = 0.02). In follow-up samples, chemotherapy significantly down regulated expression of all markers. In addition, lesional expression of IL-17 was confirmed at protein level by Immuno-histochemistry. Further, systemic presence of Th17 responses (IL-17 and IL-23) was observed in plasma samples from PKDL patients. In functional assays, TSLA stimulated the secretion of IL-17 and IL-23 from PBMCs of PKDL patients, while recIL-17 enhanced the production of TNF-α as well as nitric oxide (NO) in PKDL compared to control (TNF-α, P = 0.0002; NO, P = 0.0013). Further, a positive correlation was evident between lesional mRNA expression of IL-17 and TNF-α during PKDL.

Conclusion/Significance

The results highlight key immune modulators in PKDL and provide evidence for the involvement of Th17 type responses in the disease pathogenesis.

Post kala azar dermal leishamniasis (PKDL), an unusual dermatosis, develops in 5–15% of apparently cured visceral leishmaniasis cases in India and in about 60% of cases in Sudan. PKDL cases assume importance since they constitute an important human reservoir for the parasite. Host immunological responses, considered as major factors in PKDL development, are poorly understood. Limited studies have been performed to explore the host immune responses and that too, restricted to a few immune parameters. The present study employed cDNA array technique that identified various host immuno-determinants including cytokines, chemokines, apoptotic and signaling molecules which were not reported previously in PKDL. In addition, we showed for the first time that Th17 responses are present during L. donovani infection in PKDL which possibly contributes significantly to disease pathogenesis by inducing TNF-α and nitric oxide production. Our findings lead to improved understanding of the host parasite interaction in terms of immune responses and pathology in tissue lesions of PKDL.

Drug susceptibility in Leishmania isolates following miltefosine treatment in cases of visceral leishmaniasis and post kala-azar dermal leishmaniasis

Background

With widespread resistance to antimonials in Visceral Leishmaniasis (VL) in the Indian subcontinent, Miltefosine (MIL) has been introduced as the first line therapy. Surveillance of MIL susceptibility in natural populations of Leishmania donovani is vital to preserve it and support the VL elimination program.

Methodology and Principal Findings

We measured in vitro susceptibility towards MIL and paromomycin (PMM) in L. donovani isolated from VL and PKDL, pre- and post-treatment cases, using an amastigote-macrophage model. MIL susceptibility of post-treatment isolates from cured VL cases (n = 13, mean IC₅₀±SD = 2.43±1.44 µM), was comparable (p>0.05) whereas that from relapses (n = 3, mean IC₅₀ = 4.72±1.99 µM) was significantly higher (p = 0.04) to that of the pre-treatment group (n = 6, mean IC₅₀ = 1.86±0.75 µM). In PKDL, post-treatment isolates (n = 3, mean IC₅₀ = 16.13±2.64 µM) exhibited significantly lower susceptibility (p = 0.03) than pre-treatment isolates (n = 5, mean IC₅₀ = 8.63±0.94 µM). Overall, PKDL isolates (n = 8, mean IC₅₀ = 11.45±4.19 µM) exhibited significantly higher tolerance (p<0.0001) to MIL than VL isolates (n = 22, mean IC₅₀ = 2.58±1.58 µM). Point mutations in the miltefosine transporter (LdMT) and its beta subunit (LdRos3) genes previously reported in parasites with experimentally induced MIL resistance were not present in the clinical isolates. Further, the mRNA expression profile of these genes was comparable in the pre- and post-treatment isolates. Parasite isolates from VL and PKDL cases were uniformly susceptible to PMM with respective mean IC₅₀ = 7.05±2.24 µM and 6.18±1.51 µM.

Conclusion

The in vitro susceptibility of VL isolates remained unchanged at the end of MIL treatment; however, isolates from relapsed VL and PKDL cases had lower susceptibility than the pre-treatment isolates. PKDL isolates were more tolerant towards MIL in comparison with VL isolates. All parasite isolates were uniformly susceptible to PMM. Mutations in the LdMT and LdRos3 genes as well as changes in the expression of these genes previously correlated with experimental resistance to MIL could not be verified for the field isolates.

Resistance to antimonials has emerged as a major hurdle to the treatment and control of VL and led to the introduction of Miltefosine as first line treatment in the Indian subcontinent. MIL is an oral drug with a long half-life, and it is feared that resistance may emerge rapidly, threatening control efforts under the VL elimination program. There is an urgent need for monitoring treatment efficacy and emergence of drug resistance in the field. In a set of VL/PKDL cases recruited for MIL treatment, we observed comparable drug susceptibility in pre- and post-treatment isolates from cured VL patients while MIL susceptibility was significantly reduced in isolates from VL relapse and PKDL cases. The PKDL isolates showed higher tolerance to MIL as compared to VL isolates. Both VL and PKDL isolates were uniformly susceptible to PMM. MIL transporter genes LdMT/LdRos3 were previously reported as potential resistance markers in strains in which MIL resistance was experimentally induced. The point mutations and the down-regulated expression of these transporters observed in vitro could, however, not be verified in natural populations of parasites. LdMT/LdRos3 genes therefore, do not appear to be suitable markers so far for monitoring drug susceptibility in clinical leishmanial isolates.

Unusual presentation of cutaneous leishmaniasis

Two patients with mini-volcano type of skin lesions which showed histopathologic features of cutaneous leishmaniasis (CL) have been described. It was localised and linear in one case while widespread in the other. Both responded to sodium stibogluconate. The importance of recognising new emerging foci of CL is emphasised.

catena-Poly[ammonium (cadmium-tri-μ-thio-cyanato-κS:N;κN:S)-1,4,10,13,16-hexa-oxa-cyclo-octa-decane (1/1)]

In the title compound, {(NH(4))[Cd(NCS)(3)]·C(12)H(24)O(6)}(n), the Cd(2+) ion, the ammonium cation, one of the SCN(-) ligands and the macrocycle are located on mirror planes. The thiocyanate anions act as bridging ligands between the Cd(II) ions, leading to a polymeric chain arrangement extending along [001] around a twofold screw axis. The ammonium ions are contained within the bowl of the macrocycle via extensive N-H⋯O hydrogen bonding.

Evaluation of the usefulness of Treponema pallidum hemagglutination test in the diagnosis of syphilis in weak reactive Venereal Disease Research Laboratory sera

Background and Objectives:

Biological false positive (BFP) reactivity by the Venereal Disease Research Laboratory (VDRL) test used for diagnosis of syphilis is a cause for concern. The use of the VDRL as a screening procedure is challenged by some studies. The aim of this study is to determine the prevalence of BFP reactions in different subject groups and to assess the usefulness of Treponema pallidum hemagglutination (TPHA) test in low titre VDRL reactive sera.

Materials and Methods:

A total of 5785 sera from sexually transmitted diseases (STD) clinic attendees, antenatal clinic attendees, husbands of antenatal cases, peripheral health centres attendees (representing community population) and from patients referred from different OPDs/wards were screened for BFP reactions by the VDRL test. Sera reactive in the VDRL test were confirmed by the TPHA test.

Results:

Out of 80 qualitative VDRL reactive sera, 68 had <1:8 titre on quantitation and TPHA was positive in 59 samples, indicating BFP reactivity in 0.2% in all the subject groups. BFP was nil in the community population. The male-to-female ratio of BFP reactions was 2:1. VDRL and TPHA positivity was highest (76%) in the age group of 20-29 years. The seroprevalence of syphilis varied from 0.4% to 3.5% in different patient groups.

Conclusions:

The results of this study highlight that the TPHA positivity was high (86.8%) in sera with VDRL titre less than 1:8. Therefore, for the diagnosis of syphilis, it is recommended that a confirmatory test such as TPHA should be performed on all sera with a reactive VDRL regardless of its titre.

Comparative assessment of CDS, CLSI disc diffusion and Etest techniques for antimicrobial susceptibility testing of Neisseria gonorrhoeae: a 6-year study

BACKGROUND

A variety of techniques are available for antimicrobial susceptibility testing of Neisseria gonorrhoeae.

OBJECTIVE

The aim of this study was to find a cost-effective, reliable and easily applicable microbiological method to detect antimicrobial susceptibilities of N. gonorrhoeae in resource-poor countries.

DESIGN

Prospective study.

SETTING

Male and female STD clinic of Regional STD Teaching, Training and Research Centre, New Delhi, India.

PARTICIPANTS

N. gonorrhoeae isolates from all male and female patients presenting with acute gonococcal urethritis and cervical discharge.

MATERIAL AND METHODS

A total of 295 consecutive N. gonorrhoeae isolates during 2005-2010 was used to compare the Clinical and Laboratory Standards Institute (CLSI) and CDS disc diffusion technique with Etest by performing antimicrobial susceptibility testing in parallel for penicillin, tetracycline, ceftriaxone, ciprofloxacin and spectinomycin. WHO reference strains were used as controls.

RESULTS

CDS disc diffusion zones of inhibition showed that complete percentage agreement for penicillin, ciprofloxacin and tetracycline was high with their analogous Etest minimal inhibitory concentrations in comparison to CLSI disc diffusion technique, that is, 91.5%, 92.9% and 99.3% versus 87.5%, 88.5% and 74.9%, respectively. CDS results had less number of major and minor category discrepancies in comparison to CLSI and CDS method showed excellent correlation coefficient (r=1) with Etest for all five antimicrobial agents tested in comparison to CLSI (r=0.92). It was very poor (r=0.61) by CLSI method for tetracycline. The correlation coefficients between the two methods and the Etest were identical if tetracycline was removed from the CLSI analysis.

CONCLUSIONS

The CDS technique is an attractive alternative for N. gonorrhoeae susceptibility testing and is recommended for monitoring the antimicrobial susceptibility in less developed and resource-poor settings to facilitate enhanced antimicrobial resistance surveillance when the WHO Gonococcal Antimicrobial Surveillance Programme is undergoing expansion to meet the ongoing challenges of surveillance and control of gonococcal antimicrobial resistance.

Deprotonated N-(2,4-Dinitrophenyl)amino Acids Undergo Cyclization in Solution and the Gas Phase

The collisionally activated mass spectral fragmentations of N-(2,4-dinitrophenyl)alanine and phenylalanine [M - H](-) may be gas-phase analogs of the base-catalyzed cyclization of N-(2,4-dinitrophenyl)amino acids in aqueous dioxane. This latter reaction is one source of the 2-substituted 5-nitro-1H-benzimidazole-3-oxides, which are antibacterial agents. The fragmentation of both compounds, established by tandem mass spectrometric experiments and supported by molecular modeling using DFT methods, indicate that the [M - H](-) ions dissociate via sequential eliminations of CO(2) and H(2)O to produce deprotonated benzimidazole-N-oxide derivatives. The gas-phase cyclization reactions are analogous to the base-catalyzed cyclization in solution, except that in the latter case, the reactant must be a dianion for the reaction to occur on a reasonable time scale. The cyclization of N-(2-nitrophenyl)phenylalanine, which has one less nitro group, requires a stronger base for the cyclization than the compound with a second nitro group at the 4-position. Following losses of CO(2) and H(2)O are expulsions of both neutral molecules and free radicals, the latter being examples of violations of the even-electron ion rule.