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P V Patil

Publications and source records attributed to P V Patil.

13 recordsLinked to original sources
PubMed2004

Effect of fixation of shoulder and elbow joint movement on the precision of laparoscopic instrument manipulations.

BACKGROUND: Motion analysis of the upper limb and the surgical instruments is used for objective assessment of endoscopic manipulations. The aim of this study was to investigate the effect of fixation of shoulder and elbow joint movement on the precision of laparoscopic instrument manipulations. METHODS: Two experiments were conducted to correlate hand movement with instrument tip during free and restricted movement of the shoulder and elbow joints. A three-dimensional infrared optical tracking system has been used. Five subjects participated in the study, and each completed the range of movements twice. End points were velocity (m/s), angular velocity (r/s) and acceleration (m/s2). RESULTS: There was a weak correlation for all end points between the instrument tip and individual joint movement during free upper limb movement (r < 0.4). With restricted movement of the shoulder and elbow joints, the correlation between hand movement and instrument tip was found to be good for the velocity (r = 0.66 for flexion; r = 0.72 for abduction; r = 0.56 for supination) and angular velocity (r = -0.83 for flexion; r = -0.48 for abduction; r = -0.70 for supination), but weak for the acceleration (r < 0.4). CONCLUSIONS: The characteristics of hand movements do not correlate with movement of the laparoscopic instrument tip when the upper limb is unsupported. The precision of laparoscopic surgical manipulations is increased if both joints (shoulder and elbow) are supported.

Elbow Joint↗
PubMed2003

Effect of the angle between the optical axis of the endoscope and the instruments' plane on monitor image and surgical performance.

BACKGROUND: The aim of the study was to examine the effect of the angle between optical axis of the endoscope and the instruments' plane (OAIP) on the monitor display angle (approach angle between the two instruments on a two-dimensional monitor) and endoscopic task performance. METHODS: Two experiments were carried out in the Advanced Dundee Endoscopic Psychomotor Tester (ADEPT) using a standard two-dimensional video endoscopic system. In the first experiment, the monitor display angle was measured during use, with OAIP angles ranging between 0 and 80 degrees (at 10 degrees increments) and manipulation angles varying between 45 and 120 degrees (at 15 degrees increments). In the second experiment, 10 surgeons tied 500 intracorporeal knots with OAIP angles of 0 degrees (optical axis in the same plane as the instruments), +15 degrees and +30 degrees (viewing above the instruments' plane), and -15 and -30 degrees (optical axis looking from below instruments' plane). The end points were the execution time and knot quality score (KQS). RESULTS: In the first experiment, instruments entered the visual field from lateral sides of the monitor with an apparent 180 degrees monitor display angle with a 0 degrees OAIP angle, whereas the monitor display angle approached the actual manipulation angle between the two needle drivers when an 80 degrees OAIP angle was used. In the second experiment, the instruments appeared to enter the image field from the side of the surgeon when the endoscope viewed the instruments from above, whereas instruments entered the field from the opposite side to the surgeon when the endoscope viewed instruments' plane from below. As a result, use of 0 and +15 degrees OATP angles yielded significantly shorter execution times: 70 s compared to 83, 93, and 77 s for +30, -30, and -15 degrees OAIP angles ( p < 0.001), with KQS of 39 degrees and 40 vs 38, 36, and 34%, respectively ( p = 0.257). CONCLUSIONS: The angle between the optical axis of the endoscope and instruments' plane determines how the instruments appear to enter the operative field. The monitor display angle between the instruments is different from the real manipulation angle unless the OAIP angle is near 80 degrees. The apparent entry of instruments into the operative field becomes intuitive for the surgeon only if the endoscope is viewing from above or in the same plane as the instruments. Hence, the best performance for endoscopic knot tying is obtained with this configuration, and execution time increases significantly with viewing from below the instruments' plane.

Endoscopes↗
PubMed2001

Mechanical stimulation induces pp125(FAK) and pp60(src) activity in an in vivo model of trabecular bone formation.

Utilizing an in vivo model of trabecular bone formation, we demonstrated the temporal and spatial activation of pp125(FAK) in response to specific mechanical load stimuli. Bone chambers equipped with hydraulic actuators were aseptically inserted into each proximal tibial metaphysis of adult, male dogs under general anesthesia. The load stimulus consisted of a trapezoidal waveform, with a maximum compressive load of 17.8 N, loading rate of 89 N/s, at 1 Hz frequency. One chamber was loaded for 2 (120 cycles), 15 (900 cycles), or 30 min (1,800 cycles), whereas the contralateral chamber served as unloaded control. Bone chambers were biopsied at postload time points of 0, 15, and 45 min. Load-induced activation of FAK was rapid, and the duration of activation was dependent on the number of applied load cycles. Mechanical stimulation increased the association of FAK with Src and the time course of complex formation paralleled the temporal activation of FAK. Evaluation of cryosections revealed prominent FAK immunoreactivity among marrow fibroblasts and stromal cells.

Animals↗
PubMed2000

The use of protocatechuate dioxygenase for maintaining anaerobic conditions in biochemical experiments.

The study of redox-active systems often requires the maintenance of anaerobic conditions. The glucose oxidase system has often been used to maintain anaerobic conditions, but it has some drawbacks, such as the production of H(2)O(2) and limitations on stability. Protocatechuate dioxygenase from Burkholderia cepacia and the substrate, protocatechuate, constitute an alternate effective oxygen-scrubbing system that can be used in a wide variety of biochemical experiments. We have shown its suitability for maintaining rigorous anaerobic environments in solutions of pH 6-9, at temperatures from 4 to 35 degrees C, and for periods of time up to 15 months. The enzyme system was shown to be stable under these conditions and effective for maintaining anaerobic conditions in titrations of FAD. It is also suitable for scrubbing various types of apparatus such as stopped-flow instruments for anaerobic experiments.

Anaerobiosis↗
PubMed2000

An in vivo model for investigations of mechanical signal transduction in trabecular bone.

The premise that bone cells are able to perceive and respond to mechanical forces is well accepted. This article describes the use of an in vivo hydraulic bone chamber for investigations of mechanical signal transduction. The servohydraulic loading mechanism was activated to apply a controlled compressive load to the woven trabecular bone that formed in one chamber, while the contralateral chamber served as an unloaded control. Specimens were harvested at a series of postload time points, and the cellular response to loading was evaluated by cytochemical, histomorphometric, and Northern blot analysis. A repetitive daily load stimulus elicited osteoblast biosynthetic activity characterized by an initial increase in type I procollagen by day 3 and a subsequent rise in alkaline phosphatase (ALP) activity after the sixth daily load episode. Application of a single load episode induced a biphasic pattern of c-fos and zif-268 gene expression with up-regulation at 30 minutes, down-regulation at 12 h, and up-regulation 24 h after the mechanical stimulus. The results show that a synchronized pattern of bone cell activity and gene expression occurs in response to controlled mechanical stimulation and that candidate load-responsive molecular mediators can be evaluated easily by this model.

Alkaline Phosphatase↗
PubMed1999

Perspectives on tissue engineering of bone.

The normal repair and regeneration of bone occurs through an ordered and regulated sequence of cellular events. Successful replacement of bone through tissue engineering likely will be dependent on the recapitulation of this cascade of events. This report presents some of the principles to be considered in the design of engineered bone constructs. The role of cells, a supporting matrix, and endogenous or exogenous biologic or mechanical factors are introduced. The authors' experience with a gene therapeutic approach to bone regeneration is presented as one example of using the principles discussed to promote reproducible bone formation.

Animals↗
PubMed1997

Fine needle aspiration cytology of papillary carcinoma thyroid with Hashimoto's thyroiditis--report of two cases.

Two cases of papillary carcinoma of thyroid with clinically unsuspected Hashimoto's thyroiditis were diagnosed on Fine Needle Aspiration Cytology (FNAC) in females aged 22 yrs, and 57 yrs., who presented with a solitary thyroid nodule. The frequency of carcinoma in Hashimoto's thyroiditis varies between 0.5 to 23.7%, depending on the stringency of diagnostic criteria applied. We believe that this possibility must be kept in mind when ever an aspirate of a solitary nodule shows profuse lymphocytes and Hurthle cells.

Adult↗
PubMedDate not supplied

Sediment cytology in bone biopsies.

The cytologic examination of smears prepared from the sediment of biopsy specimen fixatives ("sediment cytology") was used to study 70 bone lesions biopsied with a suspicion of malignancy. The smears were adequately cellular in most cases and showed good morphologic preservation; some contained fragments of tissue. Cytology was able to identify the smears from the 47 malignant lesions as malignant, but was not always able to identify the histologic type. While the osteoclastomas, Ewing's sarcomas and metastatic carcinomas were accurately diagnosed, the osteogenic sarcomas could only be identified as sarcomas and the scanty smears from chondrosarcomas only permitted a diagnosis of malignancy. The latter was also true for soft tissue lesions and lymphoma involving the bones. The 12 benign lesions yielded less cellular specimens and were more difficult to cytologically diagnose. The 11 inflammatory lesions were identified as nonmalignant. While this simple technique of sediment cytology can provide an early diagnosis for bone lesions, the final diagnosis requires the histopathologic study of the actual biopsy specimen.

Biopsy↗