Photo-Excited Toluidine Blue Disaggregates the Repeat Tau and Modulates End-Binding Protein EB1, Cytoskeletal Structure in Neuronal Cells

BACKGROUND/AIMS

Alzheimer's disease is a progressive neurological disorder characterized by the intracellular accumulation of Tau protein aggregates. In the present work, we studied the effect of Toluidine Blue and photo-excited Toluidine Blue on the aggregation of repeat Tau using in vitro assays.

METHODS

The in vitro experiments were carried out on recombinant repeat Tau which was purified by cation exchange chromatography. The ThS fluorescence analysis was used to study the aggregation kinetics of Tau. CD spectroscopy and electron microscopy were used to study the secondary structure and morphology of Tau respectively. The actin cytoskeleton modulation was studied in Neuro2a cells with help of immunofluorescent microscopy.

RESULTS

Results showed that Toluidine Blue efficiently inhibited the formation of higher-order aggregates, which was evidenced by Thioflavin S fluorescence assay, SDS-PAGE, and TEM. Immunofluorescence studies on the cytoskeleton of Neuro2a cells showed that Toluidine Blue and photo-excited Toluidine Blue treatment at a non-toxic concentration of 0.5 µM stimulated the formation of actin-rich lamellipodia and filopodia structures. Tubulin networks were also differentially modulated after the treatment of Toluidine Blue and photo-excited Toluidine Blue. End-binding protein 1 (EB1) levels were observed to increase after Toluidine Blue and photo-excited Toluidine Blue treatment indicating accelerated microtubule polymerization.

CONCLUSION

The overall study suggested that Toluidine Blue inhibited the aggregation of soluble Tau and photo-excited Toluidine Blue disaggregated the pre-formed Tau filaments. In our study, TB and PE-TB were observed to be potent against Tau aggregation. We observed a distinctive modulation of actin, tubulin networks, and EB1 levels after TB and PE-TB treatment, which suggested that TB and PE-TB have potency against cytoskeleton deformities.

Bacopa monnieri reduces Tau aggregation and Tau-mediated toxicity in cells

Alzheimer's disease is a neurodegenerative disease characterized by progressive memory loss and behavioral impairments. In the present study, the ethanolic extract of Bacopa monnieri was studied for its potency to inhibit Tau aggregation and rescuing of the viability of Tau-stressed cells. Bacopa monnieri was observed to inhibit the Tau aggregation in vitro. The cells exposed to Bacopa monnieri were also observed to have a low level of ROS and caspase-3 activity. The immunoblot and immunofluorescence analysis showed that Bacopa monnieri acts as an antioxidant and restored the Nrf2 levels in Neuro2a cells. Bacopa monnieri treatment to Neuro2a cells was observed to reduce the phospho-Tau load in formaldehyde-stressed cells. Furthermore, the treatment of Bacopa monnieri reduced the phosphorylation of GSK-3β in formaldehyde-stressed cells. Ran and NUP358 are the key proteins involved in nuclear transport. It was observed that formaldehyde treatment impaired the nuclear transport by missorting the NUP358 arrangement in Neuro2a cells. On the contrary, Bacopa monnieri treatment restored the NUP358 arrangement in cells. The overall results of the present study suggested that Bacopa monnieri could be considered a potent herb against Tau phosphorylation and Tau aggregation, which projects it as a promising formulation for Alzheimer's disease.

Role of Microglia in Regulating Cholesterol and Tau Pathology in Alzheimer's Disease

Cholesterol, a principal constituent of the cell membrane, plays a crucial role in the brain by regulating the synaptic transmission, neuronal signaling, as well as neurodegenerative diseases. Defects in the cholesterol trafficking are associated with enhanced generation of hyperphosphorylated Tau and Amyloid-β protein. Tau, a major microtubule-associated protein in the brain, is the key regulator of the mature neuron. Abnormally hyperphosphorylated Tau hampers the major functions related to microtubule assembly by promoting neurofibrillary tangles of paired helical filaments, twisted ribbons, and straight filaments. The observed pathological changes due to impaired cholesterol and Tau protein accumulation cause Alzheimer's disease. Thus, in order to regulate the pathogenesis of Alzheimer's disease, regulation of cholesterol metabolism, as well as Tau phosphorylation, is essential. The current review provides an overview of (1) cholesterol synthesis in the brain, neurons, astrocytes, and microglia; (2) the mechanism involved in modulating cholesterol concentration between the astrocytes and brain; (3) major mechanisms involved in the hyperphosphorylation of Tau and amyloid-β protein; and (4) microglial involvement in its regulation. Thus, the answering key questions will provide an in-depth information on microglia involvement in managing the pathogenesis of cholesterol-modulated hyperphosphorylated Tau protein.

A comparative study of different modalities of treatment in nicotine dependence syndrome

There are different modalities for management of Nicotine dependence, but it is still inconclusive which is the best modality for the treatment of Nicotine dependence syndrome (NDS). In this background the present study was carried out to assess the efficacy and to compare different modalities for the treatment of NDS.

METHODS

Patients diagnosed as NDS as per ICD-10 were taken up for study. These patients were administered proforma to elicit sociodemographic details, Fagerstrom test for Nicotine Dependence, Questionnaire of Smoking Urges-Brief and breath analysis was done using carbon monoxide meter. Assessment was done at base line and at weekly follow-ups for 12 weeks. Patients were divided into six groups randomly. Group A received BUP at a dose of 150mg/day for 3 days; subsequently increased to 300mg/day, Group B: for initial 6 weeks Nicotine gum of 4mg every 1-2 hourly was used and next 6 weeks every 2-4 hourly was used, Group C: BI, Group D: BI+BUP, Group E: BI+NRT, Group F received BUP+NRT+BI.

RESULTS

The quit rates at end of the study were BUP-30%, NRT-26.66%, BI-23.33%, BI+BUP-43.33%, BI+NRT-33.33%, and BI+BUP+NRT-50%. BI+BUP+NRT had 2-3 times more quit rates than the individual modality treatment group.

CONCLUSION

There was no statistically significant difference between the study groups, but there was clinical difference in quit rates. Among the groups BI+BUP+NRT had higher quit rates compared to other groups. Combination modalities yield better quit rates than individual modalities.

Case report on anorexia nervosa

Anorexia nervosa is an eating disorder characterized by excessive restriction on food intake and irrational fear of gaining weight, often accompanied by a distorted body self-perception. It is clinically diagnosed more frequently in females, with type and severity varying with each case. The current report is a case of a 25-year-old female, married for 5 years, educated up to 10(th) standard, a homemaker, hailing from an upper social class Hindu (Marvadi) family, living with husband's family in Urban Bangalore; presented to our tertiary care centre with complaints of gradual loss of weight, recurrent episodes of vomiting, from a period of two years, menstrual irregularities from 1 year and amenorrhea since 6 months, with a probable precipitating factor being husband's critical comment on her weight. Diagnosis of atypical anorexia nervosa was made, with the body mass index (BMI) being 15.6. A multidisciplinary therapeutic approach was employed to facilitate remission. Through this case report the authors call for the attention of general practitioners and other medical practitioners to be aware of the symptomatology of eating disorders as most patients would overtly express somatic conditions similar to the reported case so as to facilitate early psychiatric intervention.

Evaluation of immuno efficiency of hemorrhagic septicemia vaccine strain (vaccine seed)

OBJECTIVE

To compared seed culture of hemorrhagic septicemia (HS) bacteria which was used to produce vaccine for its antibody induction efficiency before and after passaging in natural host (calf) using laboratory animals.

METHODS

Serial dilution of virulent bacteria was injected in to mice which were immunized with HS vaccine which was obtained from seed bacteria before and after back passaged in calf. Ratio of survived and dead was calculated by Reed-Meunch hypothesis and the LD50 value for each vaccine trial groups were calculated.

RESULTS

The immunological study revealed that vaccine prepared from back passaged seed culture showed greater improvement in its immunopotency than seed vaccine (before back passage). Around 200 mice were used to study the immuno efficiency of vaccine. Each mouse was from the same source, which were free from the Pastuerella infection previous to expose to trial infection. The same broth culture of HS was used to induce infection in mice in both trials (vaccine before back passage and vaccine after back passage). The 0.2 mL of broth dilution from 10(-1) to 10(-10) was used, as dilution increases, death rate decreases. It indicates the minimum load of bacterium is required to induced infection.

CONCLUSIONS

Obtained results revealed that back passaged vaccine seed HS bacteria in its natural host had provided better immune efficiency to the culture than laboratory stock culture, and this findings recommended that regular annual back passage was mandatory for the vaccine seed culture of Pastuerella multocida bacteria for better establishment of immune potent vaccines.

A comparison of early and delayed arthroscopically-assisted reconstruction of the anterior cruciate ligament using hamstring autograft

Delayed rather than early reconstruction of the anterior cruciate ligament is the current recommended treatment for injury to this ligament since it is thought to give a better functional outcome. We randomised 105 consecutive patients with injury associated with chondral lesions no more severe than grades 1 and 2 and/or meniscal tears which only required trimming, to early (< two weeks) or delayed (> four to six weeks) reconstruction of the anterior cruciate ligament using a quadrupled hamstring graft. All operations were performed by a single surgeon and a standard rehabilitation regime was followed in both groups. The outcomes were assessed using the Lysholm score, the Tegner score and measurement of the range of movement. Stability was assessed by clinical tests and measurements taken with the KT-1000 arthrometer, with all testing performed by a blinded uninvolved experienced observer. A total of six patients were lost to follow-up, with 48 patients assigned to the delayed group and 51 to the early group. None was a competitive athlete. The mean interval between injury and the surgery was seven days (2 to 14) in the early group and 32 days (29 to 42) in the delayed group. The mean follow-up was 32 months (26 to 36).

The results did not show a statistically significant difference for the Lysholm score (p = 0.86), Tegner activity score (p = 0.913) or the range of movement (p = 1). Similarly, no distinction could be made for stability testing by clinical examination (p = 0.56) and measurements with the KT-1000 arthrometer (p = 0.93).

Reconstruction of the anterior cruciate ligament gave a similar clinical and functional outcome whether performed early (< two weeks) or late at four to six weeks after injury.

Sacral chordomas: a 10-year study

A retrospective analysis of 14 cases of sacral chordoma seen between 1984 and 1993 at the Kidwai Memorial Institute of Oncology is reported. The mean patient age was 54 years, with 13 males and one female. Seventy-one per cent of patients presented with symptoms related to a painful sacral mass. Eight patients underwent radical surgery and two had adjuvant radiotherapy. One patient had a partial tumour resection. Three patients received radical radiotherapy. Two patients were offered only pain relief medication. The median follow-up was 33 months. The actuarial overall survival (OS) at 5 years was 48%. In the 12 patients in whom curative therapy was attempted, the 5-year OS was 56% and progression-free survival was 36%. Four patients developed local recurrence and three developed distant metastasis.

The scapular fasciocutaneous flap: a new flap for reconstruction of the posterior neck

The axial, myocutaneous and free flaps have made immediate reconstruction of head and neck defects possible. Notwithstanding this remarkable progress, defects of the posterior neck leave the reconstructive surgeon with very little choice. The scapular fasciocutaneous flap is easy to harvest, reliable and versatile, with functional and cosmetic results comparable to free flaps. We describe the anatomy and the technique of this new donor site, along with a case report.

Neoadjuvant Cis-DDP in esophageal cancers: an experience at a regional cancer centre, India

We are analysing the results of 80 patients who underwent surgery during 1983-84 for esophageal cancer. Forty patients who received pre-operative single agent Cis-DDP were grouped under "A" and 40 patients who went for surgery directly were grouped under "B". Twenty-two patients (55%) of Group A showed tumor necrosis. Both groups underwent resection and hand-sewn anastamosis of the esophagus. There were 10 post-operative deaths among 80 resected cases, 9 of them being from anastomatic leak. Cis-DDP has induced negligible side effects. A comparatively high survival rate during early years in patients who responded to Cis-DDP suggests that neoadjuvant chemotherapy might be of value.