Enhancing sensation in diabetic neuropathic foot with mechanical noise

OBJECTIVE: Localized low-level mechanical or electrical noise can significantly enhance tactile sensitivity in healthy young subjects and older adults. This phenomenon is termed stochastic resonance (SR). In this study, we examined the effect of SR on vibratory and tactile sensation in patients with moderate to severe diabetic peripheral neuropathy. RESEARCH DESIGN AND METHODS: A total of 20 subjects were included in the study. The vibration perception threshold (VPT) test and the Semmes-Weinstein filament (SWF) threshold at the plantar surface of the left foot and the big toe were determined under two mechanical noise stimulus conditions: null (no noise) condition and at 10% lower than each subject's mechanical noise threshold of perception. RESULTS: The baseline values (mean +/- SD) were as follows: Neuropathy Symptom Score (NSS) 5.2 +/- 2.5, Neuropathy Disability Score (NDS) 5.0 +/- 2.1, VPT 24 +/- 11 V, and SWF threshold 5.6 +/- 0.8 at the plantar surface of the foot and 5.3 +/- 0.9 at the big toe. The VPT improved significantly from 24 +/- 11 under null condition to 19 +/- 10 V with mechanical noise (P < 0.0001). Mechanical noise also significantly increased the number of detections of the SWF at the plantar surface of the foot (detection rate 66 +/- 11 vs. 59 +/- 15%, P < 0.02) but not at the big toe (63 +/- 10 vs. 61 +/- 16%, P = NS). CONCLUSIONS: Mechanical noise stimulation improves vibration and tactile perception in diabetic patients with moderate to severe neuropathy. Additional studies are required to examine the effect of long-term noise stimulation on parameters of nerve function.     

Phase II clinical trial of 5-fluorouracil, trimetrexate, and leucovorin (NFL) in patients with advanced pancreatic cancer

Background. Advanced pancreatic cancer has limited treatment options. 5-fluorouracil (5-FU) is frequently used in the treatment of pancreatic cancer. Preclinical studies suggest synergism between trimetrexate (TMTX), 5-FU, and leucovorin (NFL). Aim. We conducted a phase II trial to evaluate the activity and safety of NFL in pancreatic cancer. Method. Eligible patients (n=21) with untreated advanced pancreatic cancer were treated with 110 mg/m² intravenous (IV) THTX on day 1 and 200 mg/m² IV leucovorin prior to 500 mg/m² IV 5-FU on day 2. Oral leucovorin (15 mg every 6 h for seven doses) started intravenous 24 h later. Results. Treatment was administered for 6 wk followed by a 2-wk rest period. Response was evaluated every 8 wk. All patients were evaluable for response and toxicity. Most patients (80%) had distant metastases. Forty-five cycles of chemotherapy were administered. The most common serious toxicities were Grade 3 diarrhea (23.8%) and nausea and vomiting (14.2%). The response rate was 4.1% (95% CI, 0–23%), median survival was 6.8 mo, and 1-yr survival was 19%. Conclusion. Treatment with NFL is well-tolerated in patients with advanced pancreatic cancer. The median survival and 1-yr survival in these patients with poor prognosis compares favorably with other treatment options.     

Nonreciprocal and host-dependent interference between two variants of influenza virus

Two variants of the WSN strain of influenza virus, designated F and C because they produce distinct plaque types on bovine kidney (MDBK) cells, have been found to exhibit nonreciprocal and host-dependent interference. The interference is mediated by C particles obtained from either MDBK cells or chick embryo fibroblasts (CEF). It does not operate in CEF, and in MDBK cells the C variant is always the interference-inducer regardless of which virus enters the cell first. Standard virus prepared in CEF contains at least 20 interfering units per plaque-forming unit. Increasing the particle to infectivity ratio of the C preparation increases the number of interfering particles per plaque-forming unit. UV-inactivated C virions retain the capacity to interfere with F synthesis. Strains of virus with limited capacity to grow in MDBK cells also interfere with the synthesis of F but not of C.Preinfection of MDBK cells with F results in enhancement of early yields of C. This is not observed in CEF. Enhancement can be induced by F nonplaque formers but not by UV-inactivated virus or by other strains of influenza virus. The experiments suggest that C virions interfere with an early step in the replication of F by usurping components which are essential for virus replication and which are presented in limiting amounts in infected MDBK cells.     

Conjugate between hydrolyzed collagen from defatted seabass skin and epigallocatechin gallate (EGCG): characteristics,antioxidant activity and in vitro cellular bioactivity

Conjugation between peptides and polyphenols, especially epigallocatechin gallate (EGCG) using covalent grafting, is a promising method that can modify peptides or augment their antioxidant activities. Moreover, the resulting conjugates can be intensively served as functional ingredient or supplement. Thus, the objectives of the present study were to investigate the grafting between hydrolyzed collagen (HC) from defatted seabass skin and EGCG and to study characteristics as well as bioactivities of the obtained HC–EGCG conjugate. Levels of EGCG used (1–5%, w/w) affected surface hydrophobicity (SH) and antioxidant activities of the conjugates. Overall, the addition of EGCG at 3% to HC (HC–3% EGCG) increased SH, ABTS radical scavenging and metal chelating activities (p < 0.05). FTIR spectra of HC–3% EGCG revealed the interaction between HC and EGCG via H-bonding and covalent interaction. Sephadex G-25 fraction of conjugate with molecular weight (MW) of 2771 Da rendered the highest redox ability. When HC–3% EGCG was applied in fibroblast (MRC-5) and keratinocyte (HaCaT) cells, all levels tested (125–1000 μg mL⁻¹) had no toxicity on both cells. Higher proliferation of both cells were attained with increasing levels of HC–3% EGCG, particularly at 500 and 1000 μg mL⁻¹ (p < 0.05). Moreover, both levels used had cytoprotective ability against reactive oxygen species (ROS) as evidenced by lowered ROS and cell death detected as compared to those found in cells induced with H₂O₂ or AAPH alone (p < 0.05) for both cells. HC–3% EGCG could serve as an effective antioxidant for application in foods or as supplement for skin nourishment.

Bioactivites of hydrolyzed collagen from defatted Seabass skin were enhanced via conjugation with epigallocatechin-gallate (EGCG) using free radical grafting method.     

Comparative Drug Release Investigations for Diclofenac Sodium Drug (DS) by Chitosan-Based Grafted and Crosslinked Copolymers

The hydrogels responding to pH synthesized by graft copolymerization only and then concurrent grafting and crosslinking of monomer N-isopropyl acrylamide (NIPAAM) and binary comonomers acrylamide, acrylic acid and acrylonitrile (AAm, AA and AN) onto chitosan support were explored for the percent upload and release study for anti-inflammatory diclofenac sodium drug (DS), w.r.t. time and pH. Diclofenac sodium DS was seized in polymeric matrices by the equilibration process. The crosslinked-graft copolymers showed the highest percent uptake than graft copolymers (without crosslinker) and chitosan itself. The sustainable release of the loaded drug was studied with respect to time at pH 2.2, 7.0, 7.4 and 9.4. Among graft copolymers (without crosslinking), Chit-g-polymer (NIPAAM-co-AA) and Chit-g-polymer (NIPAAM-co-AN) exhibited worthy results for sustainable drug deliverance, whereas Crosslink-Chit-g-polymer (NIPAAM-co-AA) and Crosslink-Chit-g-polymer (NIPAAM-co-AAm) presented the best results for controlled/sustained release of diclofenac sodium DS with 93.86 % and 96.30 % percent release, respectively, in 6 h contact time. Therefore, the grafted and the crosslinked graft copolymers of the chitosan showed excellent delivery devices for the DS with sustainable/prolonged release in response to pH. Drug release kinetics was studied using Fick’s law. The kinetic study revealed that polymeric matrices showed the value of n as n > 1.0, hence drug release took place by non-Fickian diffusion. Hence, the present novel findings showed the multidirectional drug release rate. The morphological changes due to interwoven network structure of the crosslinked are evident by the Scanning electron microscopy (SEM) analysis.     

Inflammatory Mediators in Patients Receiving Long-Term Home Parenteral Nutrition

This study was designed to examine circulating and urine cytokine levels in patients receiving long-term home total parenteral nutrition (TPN) support. Twelve patients who had been receiving home TPN for more than 1 year (range, 1.3–19.5 years) were enrolled for study. To avoid the potential confounding effects of intercurrent infection, patients were studied during periods of clinical stability without clinical evidence of infection. Ten normal healthy volunteers served as controls. Serum levels of albumin and C-reactive protein, temperature, body weight, and blood white cell counts were determined. The levels of soluble tumor necrosis factor receptor II (sTNF-RII) and interleukin 6 (IL-6) were measured in serum and 24-hr urine. The results showed that the concentrations of sTNF-RII and IL-6 in 24-hr urine and serum were significantly higher in patients, indicating that long-term home TPN may be associated with a persistent low-grade inflammatory state.     

Mycobacterium thermoresistibile infection following knee-replacement surgery

We report a case of Mycobacterium thermoresistibile as a cause of infection following total knee replacement. This infection was masked by the prior isolation of a vancomycin-resistant enterococcus. The infection was resolved with long-term therapy using moxifloxacin and doxycycline.     

Cytometric bead array: a multiplexed assay platform with applications in various areas of biology

The introduction of flow cytometric bead-based technology has added a new approach for investigators to simultaneously measure multiple analytes in biological and environmental samples. This new technology allows for (1) evaluation of multiple analytes in a single sample; (2) utilization of minimal sample volumes to glean data; (3) reproducibility and results comparative with previous experiments; (4) direct comparison with existing assays; and (5) a more rapid evaluation of multiple samples in a single platform. The cytometric bead array (CBA) system enables simultaneous measurement of multiple analytes in sample volumes too small for traditional immunoassays. Results have been presented for the analysis of a variety of human cytokines. In addition, the technology allows for the design and creation of assays to measure a variety of analytes including inflammatory mediators, chemokines, immunoglobulin isotypes, intracellular signaling molecules, apoptotic mediators, adhesion molecules, and antibodies. New initiatives put forward by the Human Genome Project and the FDA require the development and use of assays for the rapid simultaneous quantitation of multiple analytes. The CBA technology provides the ability to quantify multiple proteins within a given sample, with precision and consistency.     

Blood levels of ethynylestradiol, caffeine, aldosterone and desoxycorticosterone in hypertensive oral contraceptive users

Twenty normotensive and ten hypertensive black women taking oral contraceptive (OC) were studied. Age, body weight, family medical history of hypertension, length of OC use, and type of OC were comparable. At midcycle approximately 10–12 hours following OC intake, blood was drawn and the plasma was used to determine ethynylestradiol (EE₂), caffeine, aldosterone (Aldo) and desoxycorticosterone (DOC) levels.

The results showed that in hypertensive OC users, EE₂ and caffeine levels were significantly higher (P < .01) compared to normotensive OC users. While no significant differences were found in Aldo and DOC levels between hypertensive and normotensive OC users, OC users had higher levels of Aldo (P < .01) compared to non-OC users.     

Effects of a self-etching primer and 37% phosphoric Acid etching on enamel: a scanning electron microscopic study

Objective: The purpose of this study was to compare the etching effects of a self-etching primer with 37% phosphoric acid on enamel by using a scanning electron microscope. Bond strength and the site of bond failure were also determined for brackets bonded using SEP and 37% phosphoric acid. Materials and methods: A total of 60 maxillary premolar teeth were used for this study and they were divided into four groups. First two groups were used for studying the different types of etch patterns obtained and the next two groups were used to test the bond strength with the help of Universal testing machine. After debonding, the amount of residual adhesive was assessed according to adhesive remnant index using a stereomicroscope. Results: The majority of etch patterns obtained in the 37% phosphoric acid group were type II, whereas in the SEP group, type IV pattern was more common. There was no statistically significant difference between mean bond strengths obtained with the SEP group and the phosphoric acid group. Use of SEP results in less amount of residual adhesive on tooth surface after debonding. Conclusion: SEP produces more conservative etch pattern compared to 37% phosphoric acid. Use of SEP for bonding provides similar and clinically acceptable bond strength compared to use of 37% phosphoric acid etching technique and requires less clean-up procedures hence, reduces enamel loss. Clinical significance: Use of 37% phosphoric acid for orthodontic bonding yields high bond strength but, causes enamel loss during both etching and debonding. SEPs not only provide adequate bond strength with a more conservative etch pattern but also enable easy debonding, thereby reducing the enamel damage. Keywords: Etch pattern, Enamel, SEM, Self-etching primer. How to cite this article: Nanjannawar LG, Nanjannawar GS. Effects of A Self-Etching Primer and 37% Phosphoric Acid Etching on Enamel: A Scanning Electron Microscopic Study. J Contemp Dent Pract 2012;13(3):280-284. Source of support: Nil Conflict of interest: None declared.