Biomedical subjects

G Sivakumar

Publications and source records attributed to G Sivakumar.

11 recordsLinked to original sources

PubMed2007

Avulsion of ascending lumbar and iliolumbar veins in anterior spinal surgery: an anatomical study.

To expose the disc between the 4th and 5th lumbar vertebrae in anterior spinal surgery, left to right retraction of inferior vena cava and aorta is required. This manoeuvre can be complicated by venous haemorrhage that, in most cases, is due to avulsion of the left ascending lumbar vein (ALV) or the left iliolumbar vein (ILV). We dissected 23 embalmed cadavers to assess the factors that contribute to the risk of tearing these two veins during retraction. We describe a triangular region that should help surgeons in identifying the ALV and ILV. This triangle is defined by the lateral border of the common iliac vein, the medial border of the psoas major muscle, and the superior end-plate of the L5 vertebral body. We observed that 3 cm between the termination of the left ALV, or a common stem with the ILV, and the termination of the common iliac vein is the critical distance, less than which the risk of venous avulsion is highest. Although the sample considered is small, our study seems to suggest that male patients tend to have a higher risk of venous avulsion than female patients.

Female↗

PubMed2005

HPLC screening of natural vitamin E from mediterranean plant biofactories--a basic tool for pilot-scale bioreactors production of alpha-tocopherol.

The study was performed in order to investigate a simple, efficient, reliable and rapid method of extracting and quantifying natural vitamin E for pressurized liquid extraction (PLE) as well as high-performance liquid chromatography (HPLC) analysis. Lyophilized Corylus avellana L. nut samples were powdered by high-speed milling with Waring blender for 40 s. alpha-Tocopherol was extracted from the nut tissue powder using dehydrated hexane fortified with 0.01% butylated hydroxytoluene (BHT, co-antioxidant). The rate of alpha-tocopherol accumulation showed differences among nut samples collected in different areas of Italy. Sarda Piccola nut biofactory contained higher amount (81.17 microg/g d.w) of alpha-tocopherol than other-local eleven Italian cultivar nuts. These results provide insight into the biofactory basis for alpha-tocopherol accumulation in hazelnut and give the suitable cultivar tissues to establish pilot-scale bioreactors production of natural bioactive vitamin E.

Bioreactors↗

PubMed2003

Simulation framework for electrophysiological networks: effect of syncytial properties on smooth-muscle synaptic potentials.

A building block-based software framework was developed to simulate electrophysiological networks. The synaptic potentials generated during neurotransmission were simulated in an existing discrete bidomain model of smooth muscle, using cubic, three-dimensional grids of varying sizes. The model is automatically derived and numerically solved, and the results of the simulation agree with previous results obtained analytically. An enhanced model was also proposed, incorporating an additional (junctional) capacitance in the network. The correctness of the model was verified, and the effect of the extra capacitance on the synaptic potentials was explored. It was found that, with a junctional capacitance C(i) of 1.4 x 10(-10) F incorporated, the peak amplitude of the spontaneous excitatory junction potential V(peak) declined by approximately 13% at node 0 and by approximately 37% at node 3x for a system size of 9(3). Similar results were obtained for different system sizes. V(peak) also declined as the junctional capacitance Ci was increased. In a system of size 11(30, a 200-fold increase in C(i) induced a 55% reduction at node 0. It is suggested that the type of modular simulation framework developed here may find general applicability for simulations of other physiological systems.

Electrophysiology↗

PubMed2003

Embryoidogenesis and plant regeneration from leaf tissue of Gloriosa superba.

The induction, maturation and germination of embryoids from leaf tissue of Gloriosa superba L. were developed by exploiting solid and liquid culture. Nodular calli were obtained from SH medium supplemented with 2,4-D and 2iP. In solid culture, the nodular calli when transferred to 2,4-D along with glycerol gave the best response (68.4 %) in embryoid induction after 20 days. After two subcultures at 7-day intervals in a medium with thiamine instead of glycerol, the embryoids matured. When mature embryoids were transferred to BAP and IBA medium, they gave rise to plantlets with single shoots and roots. In liquid culture, the medium supplemented with NAA and L-glutamine with continuous agitation, the embryoidogenic calli produced embryoids (85 %) after 21 days. The mature embryoids began to turn green and produced shoots and elongated "radicles" after 35 days.

Culture Techniques↗

PubMed1991

Topical phenytoin in diabetic foot ulcers.

OBJECTIVE: The efficacy of topical phenytoin in the treatment of diabetic foot ulcers was evaluated in a controlled inpatient study. RESEARCH DESIGN AND METHODS: Fifty patients were treated with topical phenytoin, and 50 patients matched for age, sex, and ulcer areas, depth, chronicity, and infection were dressed with dry sterile occlusive dressing. RESULTS: Both groups improved, but the ulcers treated with topical phenytoin healed more rapidly. Mean time to complete healing was 21 days with phenytoin and 45 days with control. The differences seen were statistically significant (P less than 0.05) via the chi 2 test. CONCLUSIONS: Phenytoin appears to be useful as a topical agent in promoting the healing of diabetic foot ulcers.

Adult↗

PubMedDate not supplied

Predicting the composition of gallstones by infrared spectroscopy.

AIM: To determine the composition of gallstones in South India by comparing visual assessment with graphic interpretation of infrared spectra. METHODS: Infrared spectroscopy (IRS) was used in qualitative analysis of 168 gallstones from Tamilnadu, Kerala and Karnataka and compared with visual interpretation. The spectrum of cholesterol, calcium bilirubinate and calcium carbonate for each stone was correlated with visual inspection. RESULTS: Fifty four percent of gallstones were of pigment variety, 43% were of mixed and the remaining 3% were cholesterol gallstones as categorised by visual interpretation. Based on infrared spectrocopic interpretation the percentages were 58%, 39% and 2% respectively. There was a good agreement between the visual inspection and IRS in classification of gallstones (Kappa value 85%; 95% CI 77-93%). CONCLUSION: Visual inspection of gallstones can predict the composition of gallstone with good accuracy and was comparable to infrared spectroscopic interpretation.

Bilirubin↗

PubMedDate not supplied

Lip prints (cheiloscopy).

External surface of the lip has many elevations and depressions forming a characteristic pattern called lip prints, examination of which is referred to as cheiloscopy. This is unique for individuals like the finger prints. The biological phenomenon of systems of furrows on the red part of the human lips was first noted and described by anthropologist R.S. Fischer, in 1902. However until 1930, anthropology merely mentioned the existence of furrows without suggesting a practical use for the phenomenon. Since 1950, the Japanese have carried out extensive research in this matter. In the period 1968 to 1971, Y.T Suchhihashi and T. Suzuki examined 1364 persons at the department of forensic odontology at Tokyo university and established that the arrangement of lines on the red part of the human lips is individual and unique for each human being. Lip print recording is helpful in forensic investigation that deals with identification of humans, based on lip traces. A lip print may be revealed as a surface with visible elements of lines representing the furrows. This characteristic pattern helps to identify the individuals since it is unique for individuals. When the lines are not clear (Only the shape of lines is printed), individual identification of human being based on this trace is extremely difficult, unless the trace contains more individual characteristics like scars, clefts etc, and often identification ends with group identification.

Adult↗

PubMedDate not supplied

Malignant melanoma of the oral cavity--case reports and review of literature.

Melanoma is a malignant tumor of melanocytes or their precursor cells. It is the third most common skin cancer and is one of the most biologically unpredictable neoplasms. Sunlight is an important etiological factor in cutaneous melanoma. Oral melanoma is relatively uncommon, exhibiting a definite predilection for palate and maxillary gingiva, and is twice as common in males as in females. We herewith report three cases of oral melanoma out of which two occurred on the palate and one in the maxillary gingiva. Their clinical presentations, histopathology and management are discussed.

Adult↗

PubMedDate not supplied

Primary de novo intraosseous carcinoma of the mandible--report of a case and review of literature.

Primary intraosseous carcinoma (PIOC) is a rare malignant odontogenic neoplasm defined as squamous cell carcinoma arising within thejaws, having no initial connection with the oral mucosa and presumably developing from the residues of the odontogenic eptihelium. A 37yr old male patient reported with the complaint of pain and swelling in the right mandible and inability to open his mouth for the past six months. Examination revealed an expansile mass that involved the right mandible and extended from the 1st premolar region to the right angle of the mandible. The alveolar ridge was markedly expanded and was covered with intact, normal appearing mucosa. Radiographic examination revealed an ill-defined radiolucent area in the right body of the mandible, which extended to the lower border. Histopathologic examination revealed a well differentiated keratinizing squamous cell carcinoma. PIOC has no specific histopathologic features and can be definitively diagnosed only upon fulfillment of various criteria. These criteria were followed in our case and reported here for its rarity.

Adult↗

PubMedDate not supplied

Ameloblastic fibro odontoma.

Ameloblastic fibro odontoma is relatively a rare mixed odontogenic tumor comprising of ameloblastic fibroma and ameloblastic odontoma. This group of lesions represent neoplastic and hamartomatous changes. Data regarding age, sex, and site of occurrence of these lesions have been uniquely described. A case of ameloblastic fibro odontoma in a 17-year-old male involving the left body of the mandible, and its radiographic, clinical symptoms and histological features is described herewith. A conservative surgical approach, including enucleation and mechanical curettage of the surrounding bone was done.

Adolescent↗

PubMedDate not supplied

Oral manifestations and analysis of salivary and blood urea levels of patients under going haemo dialysis and kidney transplant.

AIM AND OBJECTIVES: To evaluate oral manifestations in patients with renal diseases and to correlate blood and salivary urea levels in patients undergoing haemodialysis and kidney transplant. MATERIAL AND METHODS: Study group subjects were selected from patients undergoing hemodialysis and patients who had underwent kidney transplant. Adequate history was recorded. All the groups were examined extra orally and intra orally and findings were recorded. SAMPLE COLLECTION: Venous blood was collected from the antecubital fossa in control group. In patients with renal disease undergoing dialysis, blood was collectedjust prior to the dialysis. Renal transplant patients' blood samples were collected during review visit. Unstimulated saliva was collected and submitted to the laboratory immediately for urea examination by an automated analyzer. RESULTS: Extra oral manifestations like swollen face, pale skin, pedal edema, and bruises on the skin, nausea and vomiting in nearly 50% of the patiens, and oral manifestations like uraemic odour, dry mouth, and altered taste sensation were noted. There was a correlation between blood urea and salivary urea concentration in patients under going hemodialysis and kidney transplant. CONCLUSION: Saliva can be used as a non-invasive diagnostic tool.

Adolescent↗