Design of non-invasive glucose meter using near-infrared technique

Diabetics need to keep track of their blood glucose level and measure it regularly to determine their insulin dose intake and to ensure that glucose level is always within the normal range. In this article, a system that enables the measurement of blood glucose level non-invasively is designed. This article uses a near infra-red (NIR) transmittance spectroscopy, without drawing blood, puncturing the skin, or causing pain. It involves a light source and light detector circuits positioned on a certain region of the body. The attenuated received infra-red signal by the detector is a measure of the blood glucose level of that region. Data are collected from the receiving circuit and sent to a microcontroller using CoolTerm application, then exporting it to Excel Sheet, in which mean values and graphs are obtained. The performance of the circuit with and without Filtering is examined. A downward pattern was noticed, as the glucose concentration in the solution increased, the voltage output decreased, meaning that a less intensity light was detected by the receiving circuit. An improvement in the accuracy of measurements by 17% was achieved, when a notch filter is implemented to cut the voltage components corresponding to the power line noisy signals.     

Influence of polymerisation method and type of fibre on fracture strength of endodontically treated teeth

The aim of this study was to investigate (i) the effect of direct or indirect polymerisation of adhesive‐impregnated ribbon fibre under 4‐mm bulk‐filled composites on fracture strength; (ii) to compare polyethylene ribbon fibre‐reinforcement composites with short fibre‐reinforced composite; and (iii) the effectiveness of polyethylene ribbon fibre according to the restorative materials used (low‐viscous bulk‐fill composite, high‐viscous flowable composite or conventional paste composite). Seventy molars were divided into seven groups; (groups 1–2) Ribbond‐reinforced Surefil‐SDR; (group 3) Ribbond‐reinforced G Aenial Flo; (group 4) Ribbond‐reinforced G Aenial Posterior; (group 5) short fibre‐reinforced composite everX Posterior; (group 6) unfilled cavity; (group 7) intact teeth. Ribbond was adopted to cavity walls by impregnating an adhesive and using a flowable composite. In group 1, adhesive‐impregnated Ribbond was polymerised directly using a light‐curing‐unit, and indirectly in group 2 under 4‐mm bulk‐filled composite. Direct or indirect polymerisation of adhesive impregnated ribbon fibre under 4‐mm bulk‐filled composite did not change the fracture strength results. Polyethylene ribbon fibre‐reinforced groups (groups 1–4) and short fibre‐reinforced composite group (group 5) displayed similar results. Polyethylene ribbon fibre can be used safely under 4‐mm bulk‐filled composites. Ribbond‐reinforced low‐viscous bulk‐fill, high‐viscous flowable, and conventional paste composite exhibited similar fracture strength results.     

Surface expression and functional characterization of alpha-granule factor V in human platelets: effects of ionophore A23187, thrombin, collagen, and convulxin

Factor V (FV) present in platelet alpha-granules has a significant but incompletely understood role in hemostasis. This report demonstrates that a fraction of platelets express very high levels of surface-bound, alpha-granule FV on simultaneous activation with 2 agonists, thrombin and convulxin, an activator of the collagen receptor glycoprotein VI. This subpopulation of activated platelets represents 30.7% +/- 4.7% of the total population and is referred to as convulxin and thrombin-induced-FV (COAT-FV) platelets. COAT-FV platelets are also observed on activation with thrombin plus collagen types I, V, or VI, but not with type III. No single agonist examined was able to produce COAT-FV platelets, although ionophore A23187 in conjunction with either thrombin or convulxin did generate this population. COAT-FV platelets bound annexin-V, indicating exposure of aminophospholipids and were enriched in young platelets as identified by the binding of thiazole orange. The functional significance of COAT-FV platelets was investigated by demonstrating that factor Xa preferentially bound to COAT-FV platelets, that COAT-FV platelets had more FV activity than either thrombin or A23187-activated platelets, and that COAT-FV platelets were capable of generating more prothrombinase activity than any other physiologic agonist examined. Microparticle production by dual stimulation with thrombin and convulxin was less than that observed with A23187, indicating that microparticles were not responsible for all the activities observed. These data demonstrate a new procoagulant component produced from dual stimulation of platelets with thrombin and collagen. COAT-FV platelets may explain the unique role of alpha-granule FV and the hemostatic effectiveness of young platelets. (Blood. 2000;95:1694-1702)     

Thrombospondin-1 plays a profibrotic and pro-inflammatory role during ureteric obstruction

Thrombospondin-1 (TSP-1) is an endogenous activator of transforming growth factor-β (TGF-β), and an anti-angiogenic factor, which may prevent kidney repair. Here we investigated whether TSP-1 is involved in the development of chronic kidney disease using rats with unilateral ureteral obstruction, a well-known model to study renal fibrosis. Obstruction of 10 days duration induced inflammation, tubular cell atrophy, dilation, apoptosis, and proliferation, leading to interstitial fibrosis. TSP-1 expression was increased in parallel to that of collagen III and TGF-β. Relief of the obstruction at day 10 produced a gradual improvement in renal structure and function, the reappearance of peritubular capillaries, and restoration of renal VEGF content over a 7- to 15-day post-relief period. TSP-1 expression decreased in parallel with that of TGF-β1 and collagen III. Mice in which the TSP-1 gene was knocked out displayed less inflammation and had better preservation of renal tissue and the peritubular capillary network compared to wild-type mice. Additional studies showed that the inflammatory effect of TSP-1 was mediated, at least in part, by monocyte chemoattractant protein-1 and activation of the Th17 pathway. Thus, TSP-1 is an important profibrotic and inflammatory mediator of renal disease. Blockade of its action may be a treatment against the development of chronic kidney disease.     

Serum HCV-RNA levels in patients with chronic hepatitis C: Correlation with histological features

Background and study aimsLiver disease in chronic hepatitis C virus (HCV) infection ranges from minimal lesion to liver cirrhosis and sometimes eventually evolving hepatocellular carcinoma. Whether and how HCV determines the different clinical and histological manifestation of the disease is not fully understood. It has not been clearly elucidated whether the extent of liver injury induced by HCV is influenced mainly by direct cytopathic damage or by an immune-mediated response against HCV-infected hepatocytes. The aim of this study is to verify whether the amount of virus in individual patient’s serum could be related to the severity of liver injury.Patients and methodsThis study was carried out in the Gastroenterology and Hepatology Teaching Hospital, Medical City, Baghdad. Serum levels of HCV-RNA were measured in 27 patients with chronic HCV using b-DNA assay. Core liver biopsies of the patients were evaluated according to Ishak histological activity index system.ResultsThe serum HCV RNA concentrations in the patients ranged from 3.2 × 10³ to 1.2 × 10⁷ copies/ml. In all patients no correlation was observed between the variable levels of viraemia and the age of the patients. Furthermore no correlations were observed between the serum HCV RNA concentrations and the biochemical liver function test levels: Total serum bilirubin, AST, ALT, and alkaline phosphatase. Histologically; patients were categorized into four subgroups: four patients (14.8%) had minimal activity, 17 patients (63%) had mild activity, and six patients (22.2%) had moderate activity. No significant correlation was found between viraemic levels and these histological findings or their individual components: Interface hepatitis, confluent necrosis, intralobular liver cell necrosis and portal inflammation. According to the stage of the fibrosis, the patients were categorized into seven subgroups: one patient (3.7%) with stage zero, seven patients with stage one (25.9%), four patients with stage two (14.9%), eight patients with stage three (29.6%), three patients with stage four (11.1%), two patients with stage five (7.4%), and two patients in cirrhotic stage six (7.4%). There was no correlation between the serum HCV RNA concentration and the stage of fibrosis. Hepatic steatosis was observed in 16/27 patients. It was mild in nine patients, moderate in five patients, and severe in two patients. Correlation has not been observed between the serum HCV RNA viraemic level and the severity of steatosis.ConclusionSerum HCV-RNA level does not determine the degree of hepatic injury precisely and liver biopsy is necessary to accurately evaluate the extent of liver damage.     

Regional Distribution of the Anticonvulsant and Behavioural Effects of Bicuculline Injected into the Pontine Reticular Formation of Rats

Previous experimental work has established that activation of sites in the dorsal midbrain can suppress tonic hindlimb extension in the electroshock model of epilepsy. The most sensitive region for this effect is centred on the intercollicular area and is referred to as the dorsal midbrain anticonvulsant zone (DMAZ). Subsequent experiments have shown that the ipsilateral descending projection from this region to the ventrolateral pons is critically involved in mediating its tonic seizure-suppressing properties. The purpose of the present investigation was to test whether direct anticonvulsant effects in the electroshock model could be obtained from selective manipulation of DMAZ target regions in the ventrolateral pons. Animals were prepared with chronically implanted guide cannulae through which microinjections could be made directly into the lateral pontine reticular formation. Animals received injections of saline or bicuculline (25–200 pmol) administered either bilaterally or unilaterally. The effects of these injections on the animals' behaviour were determined in an open arena, after which maximal electroshock (1s, 40 mA, 50 Hz AC) was administered via ear-clip electrodes and the duration of tonic hindlimb extension was recorded. Bilateral injections of bicuculline (100 pmol) suppressed tonic seizures at a significantly higher proportion of sites centred on DMAZ target regions of the ventrolateral pons than surrounding areas. For injections centred on this region the suppressive effects of bicuculline were dose-related in the range 25–100 pmol. Unilateral injections of bicuculline into the ventrolateral pons also effectively suppressed tonic seizures in the electroshock model. Within the ventral pons there was a significant association between the behavioural and anticonvulsant effects of bicuculline; injections suppressing tonic seizures were associated with the induction of fast continuous locomotor activity, These data confirm that the DMAZ recipient region of the ventrolateral pontine reticular formation is part of a circuit which can suppress the manifestation of tonic hindlimb extension in the electroshock model. Whether this property is related to the participation of this region in normal locomotion and posture remains to be determined.     

Safe Veress needle insertion

Background/Purpose For laparoscopic surgery, the creation of pneumoperitoneum still remains a must. The insertion of a Veress needle or a trocar is never perfectly safe, and almost every kind of intraabdominal organ injury due to these insertions has been reported worldwide. Here, we describe a safe technique for creating pneumoperitoneum. Methods For the creation of pneumoperitoneum, under direct vision, the linea alba was elevated with two towel clips and then the Veress needle was inserted. We reviewed 368 patients operated on with this technique for complication rates. Ultrasound images were obtained before and during abdominal-wall lifting in 10 patients. Results There were no injuries due to the insertion of the Veress needle or trocars. In 90% of the patients, pneumoperitoneum was created successfully on the first attempt. Ultrasound examination demonstrated a mean extra safe area of 11.8 mm during abdominal-wall lifting with this technique. Conclusions Elevating the linea alba during Veress-needle insertion is safe.