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Biomedical subjects

S Agarwal

Publications and source records attributed to S Agarwal.

At least 73 records · Page 4Linked to original sources

Differences in mandibular distraction osteogenesis after corticotomy and osteotomy.

Corticotomy or osteotomy was performed on opposing sides of the mandibles in 18 goats. A custom-made distractor was used to lengthen the mandible at a rate of 1 mm/day for 10 days (total 10 mm elongation). Six goats were sacrificed respectively at 2, 4 and 8 weeks after completion of distraction. The distracted calluses were harvested and processed for radiographic, histologic, and scanning electron microscopic evaluation as well as Ca/P ratio analysis. The regenerate bone in the corticotomy side showed more bone formation and earlier mineralization than in the osteotomy side. The results of this study suggest that preservation of intramedullary vessels is beneficial to bone regeneration following mandibular osteodistraction, and that performing corticotomy may be a simple but effective way to promote the maturity of the distracted callus and shorten the time for fixation.

Animals↗

Birth weight patterns in rural undernourished pregnant women.

OBJECTIVE: To study the birth weight pattern in chronic as well as currently undernourished pregnant women. DESIGN: Prospective study of rural pregnant women by following eligible women. SETTING: Two adjoining blocks of rural Varanasi. METHOD: 3700 pregnant women from rural areas of Varanasi for whom data for anthropometry, hemoglobin, dietary intake, birth weight, fundal height and abdominal girth at 16 +/- 2, 28 +/- 2 and 36 +/- 2 weeks of gestation were recorded. Outcome measure was birth weight pattern of newborns. RESULTS: Of the births, 7.2% were < 2250 g and 27.4% < 2500 g. The weekly birth weight increments in gestation 36-42 weeks were 5-53 g, only. The fundal height did not increase during 35-39 weeks of gestation (lower by 5 cm as compared to normal). Nutrition supplement in the third trimester significantly increased fundal height and abdominal girth. Fundal height below 24.5 cm at 28 weeks of gestation (1368 women) was associated with higher low birth weight deliveries. CONCLUSION: Birth weight and fundal height increments during later pregnancy are low in undernourished pregnant women. Fundal height < 24.5 cm at 28 weeks of gestation identified women with higher risk for lowbirth weight infants. The prevalence of low birth weight was 27.4% and of prematurity was 6.6%.

Adult↗

Relationship of tissue plasminogen activator, plasminogen activator inhibitor-1 and fibrinogen with coronary artery disease in South Indian male subjects.

AIM: Prevalence rates of coronary artery disease (CAD) are reported to be very high in Asian Indians. Conventional risk factors do not explain the high rates of CAD among Indians. Recently, several newer risk factors have been reported to be associated with CAD. We measured tissue plasminogen activator (tPA) antigen, plasminogen activator inhibitor-1 (PAI-1) and fibrinogen levels in South Indian diabetic and non-diabetic subjects with and without CAD. METHODS: Four groups of subjects were studied (all males); Group 1 comprised of non-diabetic subjects without CAD (n=50). Non-diabetic subjects with CAD formed group 2 (n=50); group 3 comprised of type 2 diabetic patients without CAD (n=50) and group 4 consisted of type 2 diabetic patients with CAD (n=50). CAD was diagnosed based on coronary angiographic evidence of severe double or triple vessel disease. RESULTS: Both diabetic and non-diabetic patients with CAD had significantly higher levels of tPA, PAI-1 and fibrinogen compared to non-diabetic without CAD (p < 0.05). Patients with CAD were distributed more in the upper tertiles of these risk factors compared to those without CAD. A strong association between tPA and PAI-1 was noted in the Pearson's correlation analysis (p < 0.001). Univariate regression analysis showed tPA (Odds ratio--1.12, p = 0.03), PAI-1 (Odds ratio--1.03, p = 0.008), fibrinogen (Odds ratio--1.01, p < 0.0001), serum cholesterol (Odds ratio--1.008, p = 0.04) and hypertension (Odds ratio--3.7, p = 0.0001) to be associated with CAD. Multiple logistic regression analysis revealed hypertension (Odds ratio--4.6, 95% confidence interval--2.113-9.950, p = 0.0001) and fibrinogen (Odds ratio--1.012, 95% confidence interval--1.007-1.018, p = 0.0001) as risk factors for CAD. CONCLUSION: Our study suggests that prothrombogenic risk factors particularly fibrinogen may be associated with CAD in South Indians.

Analysis of Variance↗

Testosterone suppression in men with prostate cancer is associated with increased arterial stiffness.

Low androgen levels in men are associated with increased cardiovascular risk, through unclear mechanisms. We measured arterial stiffness ('compliance') in 21 men receiving complete testosterone suppression therapy for prostate cancer, and in 25 controls. Systemic arterial compliance (SAC), which assesses proximal aortic stiffness, was calculated by simultaneous recording of aortic flow and carotid artery pressure (the 'area method'). Aorto-femoral (A-F), aorto-radial (A-R) and femoral-dorsalis pedis (F-DP) pulse-wave velocities (PWVs) were recorded using the 'Complior' system. SAC was significantly lower in the androgen-depleted men compared to controls (0.81 +/- 0.53 vs. 1.18 +/- 0.43 arbitrary compliance units, p = 0.01, mean +/- SD). Correspondingly, their A-F PWV was higher (14.1 (10.1-21.8) vs. 12.4 (9.6-17.4) m/s, p = 0.03, median (range)). Cases tended to be older (75 +/- 7 vs. 71 +/- 6 years, p = 0.07), and to have higher systolic blood pressure (148 +/- 22 vs. 143 +/- 17 mmHg, p = 0.40); however, SAC was still significantly lower (p = 0.03) after adjustment for age and stratification for central systolic pressure (< or = or > the median). Adjustment of A-F PWV for age and central systolic pressure reduced significance to p = 0.07. There was no significant difference in peripheral PWVs between groups. In conclusion, testosterone suppression is associated with increased aortic stiffness, only partly explained by age and blood pressure. Loss of androgens in men might therefore adversely affect cardiovascular risk.

Age Factors↗

Cyclic tensile strain suppresses catabolic effects of interleukin-1beta in fibrochondrocytes from the temporomandibular joint.

OBJECTIVE: To discern the effects of continuous passive motion on inflamed temporomandibular joints (TMJ). METHODS: The effects of continuous passive motion on TMJ were simulated by exposing primary cultures of rabbit TMJ fibrochondrocyte monolayers to cyclic tensile strain (CTS) in the presence of recombinant human interleukin-1beta (rHuIL-1beta) in vitro. The messenger RNA (mRNA) induction of rHuIL-1beta response elements was examined by semiquantitative reverse transcriptase-polymerase chain reaction. The synthesis of nitric oxide was examined by Griess reaction, and the synthesis of prostaglandin E2 (PGE2) was examined by radioimmunoassay. The synthesis of proteins was examined by Western blot analysis of the cell extracts, and synthesis of proteoglycans via incorporation of 35S-sodium sulfate in the culture medium. RESULTS: Exposure of TMJ fibrochondrocytes to rHuIL-1beta resulted in the induction of inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX-2), which were paralleled by NO and PGE2 production. Additionally, IL-1beta induced significant levels of collagenase (matrix metalloproteinase 1 [MMP-1]) within 4 hours, and this was sustained over a period of 48 hours. Concomitant application of CTS abrogated the catabolic effects of IL-1beta on TMJ chondrocytes by inhibiting iNOS, COX-2, and MMP-1 mRNA production and NO, PGE2, and MMP-1 synthesis. CTS also counteracted cartilage degradation by augmenting expression of mRNA for tissue inhibitor of metalloproteinases 2 that is inhibited by rHuIL-1beta. In parallel, CTS also counteracted rHuIL-1beta-induced suppression of proteoglycan synthesis. Nevertheless, the presence of an inflammatory signal was a prerequisite for the observed CTS actions, because fibrochondrocytes, when exposed to CTS alone, did not exhibit any of the effects described above. CONCLUSION: CTS acts as an effective antagonist of rHuIL-1beta by potentially diminishing its catabolic actions on TMJ fibrochondrocytes. Furthermore, CTS actions appear to involve disruption/regulation of signal transduction cascade of rHuIL-1beta upstream of mRNA transcription.

Animals↗

Tumor necrosis factor alpha-dependent proinflammatory gene induction is inhibited by cyclic tensile strain in articular chondrocytes in vitro.

OBJECTIVE: To understand the intracellular mechanisms of the action of mechanical strain on articular chondrocytes during inflammation. METHODS: One of the major mediators responsible for cartilage destruction in inflamed articular joints is tumor necrosis factor alpha (TNFalpha). Therefore, in this study we examined the intracellular mechanisms of actions of cyclic tensile strain (CTS) on the recombinant human TNFalpha (rHuTNFalpha)-induced proinflammatory pathways in primary cultures of chondrocytes. The expression of messenger RNA (mRNA) for TNFalpha-dependent proinflammatory proteins was examined by semiquantitative reverse transcriptase-polymerase chain reaction. The synthesis of proinflammatory proteins was examined by Western blot analysis in cell extracts, followed by semiquantitative measurement of bands using densitometric analysis. Nitric oxide production was measured by Griess reaction, and prostaglandin E2 production was assessed by radioimmunoassays. The proteoglycan synthesis in chondrocytes was assessed by incorporation of Na2(35)SO4 in chondroitin sulfate proteoglycans. RESULTS: By exposing chondrocytes to CTS in the presence of TNFalpha in vitro, we showed that CTS is an effective antagonist of TNFalpha actions and acts as both an antiinflammatory signal and a reparative signal. CTS of low magnitude suppresses TNFalpha-induced mRNA expression of multiple proinflammatory proteins involved in catabolic responses, such as inducible nitric oxide synthase, cyclooxygenase 2, and collagenase. CTS also counteracts cartilage degradation by augmenting induction of tissue inhibitor of metalloproteinase 2. Additionally, CTS augments the reparative process via abrogation of TNFalpha-induced suppression of proteoglycan synthesis. Nonetheless, CTS acts on chondrocytes in a TNFalpha-dependent manner, since exposure of chondrocytes to CTS alone had no effect on these parameters. CONCLUSION: CTS of low magnitude acts as an effective antagonist of TNFalpha not only by inhibiting the TNFalpha-dependent induction of proinflammatory proteins upstream of mRNA transcription, but also by augmenting the proteoglycan synthesis that is inhibited by TNFalpha.

Animals↗

Fetal gastrointestinal malformations.

In an audit to evaluate fetal gastrointestinal (GIT) malformations, case sheets of all mothers who gave birth to newborns with GIT malformations were analysed regarding the maternal history, prenatal ultrasound and the postnatal structural malformations and perinatal management. In 1999, eleven babies were born with gastrointestinal malformations, one was a still birth. Nine had associated malformations of other systems, two had trisomy 21. Eight babies were operated in the immediate newborn period, 5 survived. Ultrasound was not very accurate in the diagnosis of GIT anomaly in this series. In view of associated chromosomal and structural anomaly a fetal ECHO and genetic amniocentesis is warranted. Most of these babies require immediate surgery after birth, so they need to be delivered in a centre which is equipped with good neonatal and pediatric surgery care.

Adult↗

Fractal analyses of osseous healing using tuned aperture computed tomography images.

The aim of this study was to evaluate osseous healing in mandibular defects using fractal analyses on conventional radiographs and tuned aperture computed tomography (TACT; OrthoTACT, Instrumentarium Imaging, Helsinki, Finland) images. Eighty test sites on the inferior margins of rabbit mandibles were subject to lesion induction and treated with one of the following: no treatment (controls); osteoblasts only; polymer matrix only; or osteoblast-polymer matrix (OPM) combination. Images were acquired using conventional radiography and TACT, including unprocessed TACT (TACT-U) and iteratively restored TACT (TACT-IR). Healing was followed up over time and images acquired at 3, 6, 9, and 12 weeks post-surgery. Fractal dimension (FD) was computed within regions of interest in the defects using the TACT workbench. Results were analyzed for effects produced by imaging modality, treatment modality, time after surgery and lesion location. Histomorphometric data were available to assess ground truth. Significant differences (p < 0.0001) were noted based on imaging modality with TACT-IR recording the highest mean fractal dimension (MFD), followed by TACT-U and conventional images, in that order. Sites treated with OPM recorded the highest MFDs among all treatment modalities (p < 0.0001). The highest MFD based on time was recorded at 3 weeks and differed significantly with 12 weeks (p < 0.035). Correlation of FD with results of histomorphometric data was high (r = 0.79; p < 0.001). The FD computed on TACT-IR showed the highest correlation with histomorphometric data, thus establishing the fact TACT is a more efficient and accurate imaging modality for quantification of osseous changes within healing bony defects.

Animals↗

No-anesthesia clear corneal phacoemulsification versus topical and topical plus intracameral anesthesia. Randomized clinical trial.

PURPOSE: To compare the intraoperative pain scores during clear corneal phacoemulsification under no anesthesia, topical anesthesia, and topical plus intracameral anesthesia. SETTING: Dr. Agarwal's Eye Hospital and Eye Research Center, Chennai, India. METHODS: Seventy-five patients were randomized to have phacoemulsification under no anesthesia, topical anesthesia, or topical plus intracameral anesthesia. Uncooperative or illiterate patients and those with hard cataract, a shallow anterior chamber, or small pupils were excluded. A protocol was established for supplemental anesthesia in case of breakthrough pain during the surgery. Each patient was asked to grade the overall severity of intraoperative pain immediately after surgery on a 10-point visual analog scale. Also evaluated were the general discomfort during surgery, discomfort from the microscope lights, surgeon stress during surgery, and total surgical time. Comparison among the 3 groups was performed using an analysis of variance. RESULTS: No supplemental anesthesia was required in any group. No significant difference was noted in the mean scores of the subjective sensation of pain with or without topical anesthesia (P =.610). The mean scores of patient discomfort from the microscope lights and surgical time were also statistically insignificant. Patient discomfort and surgeon stress during surgery were significantly greater in the no-anesthesia group than in the topical and topical plus intracameral groups (P =.0235 and P = 0.0206, respectively). CONCLUSION: No-anesthesia clear corneal phacoemulsification was performed by a highly experienced, skilled surgeon without causing an unacceptable level of pain. However, this technique is not suitable for every cataract surgeon or patient.

Adult↗

Laser in situ keratomileusis for residual myopia after primary LASIK.

PURPOSE: To analyze the results of secondary laser in situ keratomileusis (LASIK) for residual myopia after primary LASIK. SETTING: Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: A retrospective study of 50 eyes of 29 patients who had a secondary LASIK procedure was carried out. After a mean follow-up of 5.84 months +/- 3.24 (SD) after the primary procedure, the mean myopic residual refraction was -4.30 +/- 1.83 diopters (D). In 10 eyes, the primary corneal flap was lifted by blunt dissection. In 40 eyes, the flap was made with a second cut. The secondary LASIK was performed using the Chiron Technolas Keracor 217 excimer laser and the Automated Corneal Shaper microkeratome (Bausch & Lomb). RESULTS: The mean follow-up was 16.58 +/- 3.06 months. At 12 months, the mean spherical equivalent was -0.45 +/- 0.68 D (P <.05). Thirty-one eyes were emmetropic, 13 eyes were within +/-1.00 D of emmetropia, and 5 eyes were within +/-2.00 D. The mean uncorrected visual acuity improved from 20/80 (range 20/60 to 20/200) to 20/40 (range 20/20 to 20/200) (P <.005). Seventeen eyes gained 1 line of best spectacle-corrected visual acuity; 1 eye lost 1 line because of a decentered ablation with an induced postoperative astigmatism of -3.50 D cylinder. No sight-threatening complications such as a free cap, flap irregularity, corneal ectasia, or retinal complication occurred postoperatively. Epithelial ingrowth developed in 5 eyes and corneal thinning, in 1 eye. Three eyes had night glare. CONCLUSION: Secondary LASIK was a safe, stable, and effective method for the treatment of residual myopia after primary LASIK.

Adult↗

Laser in situ keratomileusis for residual myopia after radial keratotomy and photorefractive keratectomy.

PURPOSE: To evaluate the visual outcome, stability, and complications of laser in situ keratomileusis (LASIK) for residual myopia after radial keratotomy (RK) and photorefractive keratectomy (PRK). SETTING: Dr. Agarwal's Eye Hospital, Chennai, India. METHODS: Twenty eyes that had LASIK treatment for residual myopia after RK (10 eyes) or PRK (10 eyes) were retrospectively analyzed. Laser in situ keratomileusis was performed after a mean period of 24.3 months +/- 0.75 (SD) in the RK group and 22.0 +/- 1.07 months in the PRK group. RESULTS: At the last follow-up, the mean spherical equivalent was reduced from -6.05 +/- 1.98 diopters (D) to -1.26 +/- 0.32 D (P <.05) in the RK group and from -3.38 +/- 1.30 D to -0.55 +/- 0.40 D (P <.005) in the PRK group. The mean uncorrected visual acuity improved from 20/300 (range 20/600 to 20/200) to 20/40 (range 20/60 to 20/20) (P <.05) and from 20/200 (range 20/800 to 20/80) to 20/25 (range 20/40 to 20/20) (P <.05), respectively. Two eyes in the RK group and 3 in the PRK group gained 1 line of best corrected visual acuity, and 2 eyes in the RK group lost 1 line. No sight-threatening complications such as a free flap, corneal ectasia, or a retinal complication occurred. There was no statistically significant difference in corneal haze before and after LASIK. Two eyes in the RK group required repositioning of the flap because of irregular apposition to the stromal bed. CONCLUSION: Laser in situ keratomileusis was safe, effective, and stable in the treatment of residual myopia after RK and PRK.

Adult↗

Phakonit: phacoemulsification through a 0.9 mm corneal incision.

Advances in technique and equipment have led to a significant increase in the popularity of phacoemulsification and have increased its safety and efficiency. We describe a technique, phakonit, in which the lens is emulsified through a 0.9 mm clear corneal temporal incision. A cortical wash with bimanual irrigation/aspiration is followed by enlarging the incision to 2.0 mm and inserting a Staar sub-2.0 mm foldable intraocular lens. Phakonit is a safe, precise method of phacoemulsification with minimal intraoperative or postoperative complications.

Aged↗

Management of dislocated intraocular implants.

Implant dislocation may occur in the absence of appropriate capsular or zonular support (PCIOL) (11,35,53) or following traumatic injury to anterior ocular tissues (ACIOL). (11,19,20) Other factors (e.g., advanced patient age, high myopia, previous vitrectomy, pseudoexfoliation syndrome, and certain connective tissue disorders) also may predispose implant dislocation. (9,52) Although reported for all types of IOLs, implant dislocation is becoming more manageable because of the advancement of surgical techniques. A dislocated ACIOL or PCIOL may be explanted, exchanged, or repositioned. (11,48,71) Repositioning the dislocated PCIOL in the ciliary sulcus with modern vitreoretinal techniques provides an optimal environment for visual recovery. (11,71) Implant repositioning techniques generally may be categorized into the external or the internal approaches. (8,11) The former involves external suturing methods for a primary or secondary implant in the absence of adequate capsular or zonular support (15,16,31,42,56,60,61,64,66,73,76) and the latter is achieved through modern pars plana techniques. 8,11,62,69) Recently, several implant repositioning methods gaining increasing acceptance include the scleral loop fixation, (45) the snare approach, (43) the use of the 25-gauge implant forceps, (13) temporary haptic externalization, (8,11,36,71) and the use of perfluorocarbon liquids. (1,28,40,41,44) The temporary haptic externalization method combines the best features of the external and the internal approaches, avoids complex intraocular maneuvers, and allows precise scleral fixation of the dislocated IOL on a consistent basis. (8,11,71) Endoscopy provides the surgeon with optimal viewing of the anterior retropupillary anatomy that is often difficult to appreciate (e.g., capsular-zonular complex, ciliary sulcus, anterior retina, and vitreous base). (6,11) As a result, precise haptic placement is possible during the repositioning process. (6,11) However, a three-dimensional birds-eye view is lacking, and there may be a steep learning curve with endoscopy. (11) Certain characteristics of a silicone plate implant may enhance implant dislocation. (11,33,34,46,49,58) Capsular contraction following an Nd:YAG posterior capsulotomv may result in a posterior dislocation of the silicone plate implant. (11,33,34,46,49,50,58) Special techniques are available for the retrieval of the slippery dislocated silicone plate implant from the retinal surface without causing injury. (33,58) Repositioning the plate implant anterior to capsular remnants or in the ciliary sulcus may lead to recurrent dislocation, and its removal is frequently the best option. (11) Placing a second implant in the presence of a disLocated implant is ill advised because subsequent surgical management becomes more complex. (11) Surgical options include removing the dislocated implant through a Limbal or pars plana incision with special techniques, (74,75) repositioning the dislocated implant after removing the second implant," and explanting both implants. (11) Considering the increased morbidities and complications associated with the management of double implants, the surgeon should avoid the placement of a second implant in the setting of a dislocated implant. (11)

Cataract Extraction↗

Correlation between p53 gene mutations and circulating antibodies in betel- and tobacco-consuming North Indian population.

Alterations in p53 tumour suppressor gene and its expression may be implicated in the pathogenesis of betel- and tobacco-related oral cancer. There is wide regional variation in betel- and tobacco-consuming habits in different parts of the Indian subcontinent. The purpose of this study was to determine the correlations between p53 gene mutations, protein accumulation and serum antibodies in oral precancer and cancer. We analysed 30 potentially malignant oral lesions (leukoplakia) and 30 oral squamous cell carcinomas (SCCs) from northern India because the betel quid-consuming habits are different from those prevalent in other regions of India. p53 mutations were analysed by polymerase chain reaction amplification of genomic DNA and direct sequencing, p53 protein accumulation by immunohistochemical analysis and circulating p53 antibodies by ELISA. p53 gene mutations, analysed within exons 5-9, were observed in five out of 30 (17%) potentially malignant oral lesions and seven out of 30 (23%) oral SCCs. All the mutations were base substitution mutations. Three missense and two nonsense mutations were observed in potentially malignant oral lesions, while six missense and one nonsense mutations were identified in oral SCCs. The probable hot spots for the mutations were identified at codons 126, 136 and 174, which have not been observed thus far. A good correlation was observed between p53 missense mutation, p53 antibodies and p53 protein accumulation in matched potentially malignant and malignant oral lesions. All the potentially malignant and cancerous lesions harbouring missense mutations showed accumulation of p53 protein and the majority of these patients showed circulating p53 antibodies suggesting that serological detection of p53 antibodies may serve as a surrogate marker for p53 alterations in oral lesions.

Adolescent↗

Tinea capitis in two elderly women: transmission at the hairdresser.

Tinea capitis is rare in the elderly. We report cases of two elderly women who presented to our dermatology clinic within 8 weeks of each other, with scalp scaling and alopecia. In both cases, Microsporum canis grew on fungal culture of their hair, and required prolonged treatment with terbinafine. Neither of them gave a history of contact with young children or any animals. Both were fairly fit and not systemically immunocompromised. However, both had been regularly visiting the same hairdresser, during the presumed period of infectivity, making this the most likely source of infection.

Aged↗