Lymphatic filariasis: possible pathophysiological nexus with oxidative stress

Space occupying lesion of brain: An unusual site for a common infection

Filariasis is a public health menace and is a cause for concern due to its endemicity in tropical and subtropical countries of Africa, Asia, and Western Pacific. Even in endemic areas, it is rare to find filariasis in fluid specimens especially cerebrospinal fluid. Herein, we report a case of unsuspected filarial parasitic infection in an adult male admitted as a case of space occupying lesion in brain with suspicion of lymphoma/granulomatous disease on the basis of clinicoradiological details. To the best of our knowledge, such an extensive brain involvement by filariasis has not been reported before.

Immunomodulatory Activity of Sulfonamide Chalcone Compounds in Mice Infected with Filarial Parasite, Brugia malayi

Diethyl carbamazine (DEC) is being used as a sole drug to treat the lymphatic filariasis, although encountered with many limitations. Importantly, DEC works with putative host immunomodulating activities without any direct antifilarial effect. This study aimed to assess the possible modulatory effect on host immune system by sulfonamide chalcone compound, having direct antifilarial activity. The immunomodulatory activity of DEC and/or chalcone compound, 4t on mice peritoneal exudate cells (PECs) was analyzed initially in vitro. This was followed by the study of in vivo effect of these test agents in the parasitaemic BALB/c mice induced by Brugia malayi microfilariae. Cytokine profile and iNOS induction were measured from PECs of mice. 4t compound showed anti-inflammatory activity in vivo in contrast to DEC. Further 4t was found to increase anti-inflammatory and regulatory cytokines, IL-10 and TGF-β gene expression with down regulation of pro-inflammatory cytokines TNF-α and IFN-γ and iNOS in mice PECs in in vitro. In conclusion, chalcones having direct antifilarial effect also upsurges anti-inflammatory host immune response. Therefore, the results might be envisaged as 4t to be a better alternative to DEC in the chronic case of lymphatic filariasis.

Microfilaria: not always associated with eosinophilia

Filariasis is a parasitic infection seen predominantly in tropical and subtropical countries including India. In clinically suspected cases, examining a thick wet mount smear or a buffy coat film is most informative. In unsuspected cases, however, eosinophilia in a peripheral blood smear (PBS) may be the sole indicator of parasitaemia. A few cases of tissue microfilaria with the absence of peripheral blood eosinophilia (PBE) have been reported. Here, we report two cases of microfilaria in PBS in the absence of PBE. A routine screening of the tail end of all PBS at low power magnification is also advised as it may facilitate the detection of asymptomatic cases when there is a normal eosinophil count.

Nodal involvement in Oral Squamous Cell Carcinoma (SCC) patients with and without Oral Sub Mucous Fibrosis (OSMF): A Comparative Study

Aim

The aim of the study is to compare and evaluate neck node status of oral cancer patients with and without Oral Sub Mucous Fibrosis (OSMF) treated surgically.

Methodology

A total of 50 patients of Indian origin who were diagnosed with Squamous Cell Carcinoma (SCC) of oral cavity and had not taken any prior treatment were included in the study. Clinical examination and metastatic workup was done for all patients. Patients diagnosed with resectable primary and without distant metastasis were taken up for surgery. For all patients, resected specimens were sent for radical histopathological examination.

Result

The differences in nodal involvement in T₁, T₂ & T₃ sized lesions were non-significant, while in T₄ sized lesions, a statistically significant lower incidence of nodal involvement in patients with-OSMF as compared to patients without OSMF was observed.

Conclusion

Presence of N₀ neck in T₄ lesions in oral SCC patients with OSMF has potential implications on the present pattern of spread and treatment protocols, leading to need for further research with OSMF as independent risk factor for nodal involvement.

Microfilariae, a Common Parasite in an Unusual Site: A Case Report with Literature Review

Filariasis is common in tropical countries. Wuchereria bancrofti is the most common parasite which causes lymphatic filariasis in India. This paper reports the finding of microfilariae in cervicovaginal smear of a 61-year-old post menopausal woman with a brief review of literature. There are limited numbers of reports describing the presence of microfilariae in the cervicovaginal smears and even rarely as an incidental finding. It is very important to keep in mind and screen for microfilariae in the non-endemic areas also.

Blastic Phase of CML with Microfilaria: A Rare Case Report

Filariasis is a major public health concern in tropical and subtropical countries including India. There have been very few case reports of incidental filariasis in the bone marrow aspirate smears in patients with hematological malignancies. We present a case of blastic phase of chronic myeloid leukemia (CML) with associated filariasis with monocytosis. Such an association, to the best of our knowledge, is hitherto unreported. Moreover, eosinophilia was not a feature in our case. A 37-year-old male, diagnosed case of CML, presented with low grade fever, weight loss and abdominal distension for one month. Physical examination revealed massive splenomegaly and hepatomegaly. However, there was no lymphadenopathy. His hemoglobin was 10.5 g/dl, total leukocyte count was 52.31x 109 / L with platelet count of 30x 109/L .Differential leukocyte count on peripheral smear showed 21% blasts, 30% polymorphs, 16% lymphocytes, 1% myelocyte, 1%metamyelocyte, 30%monocytoid cells and 1% eosinophils. Bone marrow aspirate smears were diluted with peripheral blood and showed blasts and monocytoid cells constituting 25% and 15% of marrow nucleated cells respectively. In addition, occasional microfilaria of Wuchereria bancrofti were also seen both in the peripheral blood and aspirate smears. Based on the above findings, a diagnosis of blastic phase of CML with monocytosis with microfilaria of W.bancrofti. Hence this was an unusual case of CML blastic phase which was associated with filariasis. Moreover, inspite of having filariasis and CML, patient lacked eosinophilia and instead showed monocytosis, which is hitherto unreported.

Neurological manifestations of filarial infections

Filarial infections cause a huge public health burden wherever they are endemic. These filaria may locate anywhere in the human body. Their manifestations and pathogenic mechanisms, except the most common ones, are rarely investigated systematically. Their neurological manifestations, however, are being increasingly recognized particularly with onchocerciasis or Loa loa infections, Wuchereria bancrofti, or Mansonella perstans. The risk of developing these manifestations may also increase in cases that harbor multiple filariasis or coinfections, for instance as with Plasmodium. The microfilaria of Onchocerca and Loa loa are seen in cerebrospinal fluid. The pathogenesis of neurological manifestations of these infections is complex; however, pathogenic reactions may be caused by mechanical disruption, e.g., degeneration often followed by granulomas, causing fibrosis or mass effects on other tissues, vascular lesions, e.g., vascular block of cerebral vessels, or disordered inflammatory responses resulting in meningitis, encephalitis or localized inflammatory responses. The chances of having neurological manifestations may also depend upon the frequency and"heaviness"of infection over a lifetime. Hence, this type of infection should no longer be considered a disease of the commonly affected areas but one that may produce systemic effects or other manifestations, and these should be considered in populations where they are endemic.

Caspase dependent programmed cell death in developing embryos: a potential target for therapeutic intervention against pathogenic nematodes

Background

Successful embryogenesis is a critical rate limiting step for the survival and transmission of parasitic worms as well as pathology mediated by them. Hence, blockage of this important process through therapeutic induction of apoptosis in their embryonic stages offers promise for developing effective anti-parasitic measures against these extra cellular parasites. However, unlike in the case of protozoan parasites, induction of apoptosis as a therapeutic approach is yet to be explored against metazoan helminth parasites.

Methodology/Principal Findings

For the first time, here we developed and evaluated flow cytometry based assays to assess several conserved features of apoptosis in developing embryos of a pathogenic filarial nematode Setaria digitata, in-vitro as well as ex-vivo. We validated programmed cell death in developing embryos by using immuno-fluorescence microscopy and scoring expression profile of nematode specific proteins related to apoptosis [e.g. CED-3, CED-4 and CED-9]. Mechanistically, apoptotic death of embryonic stages was found to be a caspase dependent phenomenon mediated primarily through induction of intracellular ROS. The apoptogenicity of some pharmacological compounds viz. DEC, Chloroquine, Primaquine and Curcumin were also evaluated. Curcumin was found to be the most effective pharmacological agent followed by Primaquine while Chloroquine displayed minimal effect and DEC had no demonstrable effect. Further, demonstration of induction of apoptosis in embryonic stages by lipid peroxidation products [molecules commonly associated with inflammatory responses in filarial disease] and demonstration of in-situ apoptosis of developing embryos in adult parasites in a natural bovine model of filariasis have offered a framework to understand anti-fecundity host immunity operational against parasitic helminths.

Conclusions/Significance

Our observations have revealed for the first time, that induction of apoptosis in developing embryos can be a potential approach for therapeutic intervention against pathogenic nematodes and flow cytometry can be used to address different issues of biological importance during embryogenesis of parasitic worms.

Pathogenic nematodes currently infect billions of people around the world and pose serious challenges to the economic welfare and public health in most developing countries. At present, limitations of existing therapies warrant identification of new anti-parasitic drugs/drug targets to effectively treat and control neglected tropical diseases [NTD] caused by nematode pathogens. The current gold standard for measuring/screening drug effectiveness against most helminth parasites is in-vitro assessment of motility of parasites/larvae and larval development assays which fails to provide any conclusive idea about the precise mechanism of death of parasitic worms or their larval stages. Given the huge load of parasites or their larval stages in an infected host, a compound which shows promise in in-vitro/motility screening assays but induces necrotic death in parasites/larvae will be of limited use, as it may elicit severe inflammatory response in infected hosts. In this context, the present study, which demonstrates induction of apoptotic death in developing embryos of a pathogenic nematode as a potential drug target for the first time, and provides scope for high throughput screening of pharmacological agents for their apoptogenicity against nematode embryos, is a step forward to develop novel anti-parasitic measures to challenge NTD caused by nematode pathogens.

Malondialdehyde Content and Circadian Variations in Brain, Kidney, Liver, and Plasma of Mice

In aerobic organisms, the use of oxygen (O(2)) to produce energy is associated with the production of Reactive Oxygen Species (ROS), which reacts with biological molecules to produce oxidized metabolites such as malondialdehyde (MDA). This experiment focused on male Swiss mice 12 weeks of age synchronized for 3 weeks by the 12 h light (rest)/12 h dark (activity) span. Different and comparable groups of animals (n=10) were sacrificed at six different circadian stages: 1, 5, 9, 13, 17, and 21 h after light onset (HALO). The 24 h mean MDA level varied among organs of mice in non-stress conditions and was comparable in brain and liver but lower than in kidney. As the MDA 24 h status constitutes only a part of ROS damages in sites differing by their oxygen use, lipid composition, and detoxification capacity, the temporal patterns of their MDA content were comparatively studied in relationship to the animal rest-activity cycle. The results revealed significant circadian rhythms with the peak time located during the rest span (approximately =5 HALO) for both brain and liver, but during the activity span for the kidney ( approximately =21 HALO) and plasma (approximately =13 HALO). This chronobiological study showed that under physiological conditions, lipid peroxidation depends on several factors. The MDA peak/trough might be used as a tool to detect moments of high/low sensitivity of tissues to ROS attack in rodents.

Prophylactic evaluation of recombinant extracellular superoxide dismutase of Brugia malayi in jird model

The immunoscreening of Brugia malayi adult cDNA library with pooled endemic normal sera identified several seroreactive clones including, EC-SOD which contained a 612 bp insert and showed significant nucleotide and deduced amino acid sequence homologies with superoxide dismutase (SOD) of other nematode parasites. The SODs are known to play an important role in the protection of parasite against reactive oxygen species of the host. The coding region of the B. malayi EC-SOD (BmEC-SOD) was cloned and expressed in Escherichia coli followed by affinity purification on nickel agarose resin. Staining of native polyacrylamide gel for SOD activity of the expressed recombinant protein revealed that SOD activity inactivated by potassium cyanide and hydrogen peroxide but not by sodium azide, indicating presence of Cu/Zn-SOD. The rBm EC-SOD protein showed its activity over a broad range of pH.7.0-11.0. Further the immune protective activity of recombinant EC-SOD antigen was evaluated in susceptible host, jirds (gerbils) (Meriones unguiculatus) against B. malayi filarial infection. The immunized jirds showed 33.5% and 36% cytotoxicity against microfilariae and 42.8% and 45.5% cytotoxicity against infective larvae in in vitro antibody dependent cellular cytotoxicity (ADCC) assay and in in situ micropore chamber methods respectively. This study suggests that the rBm EC-SOD antigen could stimulate a partial protective immune response against microfilariae and infective larvae in experimental animals against filarial infection.