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Biomedical subjects

R Murthy

Publications and source records attributed to R Murthy.

At least 19 recordsLinked to original sources
PubMed2005

Botulinum toxin in ophthalmic plastic surgery.

Botulinum toxin chemodenervation has evolved greatly over the past 30 years since its introduction in the 1970s for the management of strabismus. Among ophthalmic plastic surgeons, botulinum toxins are often used as the first line treatment for facial dystonias. These toxins are also efficacious for the temporary management of various other conditions including keratopathies (through so called chemo-tarsorraphy), upper eyelid retraction, orbicularis overaction-induced lower eyelid entropion, gustatory epiphora, Frey's syndrome, and dynamic facial rhytids such as lateral canthal wrinkles (crow's feet), glabellar creases and horizontal forehead lines. This article describes the pharmacology, reconstitution techniques and common current applications of botulinum toxins in ophthalmic plastic surgery.

Botulinum Toxins↗
PubMed2003

Influence of preapheresis clinical factors on the efficiency of CD34+ cell collection by large-volume apheresis.

We evaluated 120 leukapheresis procedures (93 patients), in order to detect clinical factors that influence the efficiency of CD34+ collection using Cobe Spectra trade mark cell separators. Hematocrit was >27% and platelet count >30 000/microl in >95% of patients. Platelet transfusions were given if the postprocedure count was &<20 000/microl. Multiple regression analysis was used to analyze putative factors, and a predictive equation defined by stepwise regression modeling. The mean efficiency was 0.59 (s.d. 0.27). Sex (M>F; P=0.01), the volume processed (inversely; P=0.01) and CD34+ cell count (inversely; P=0.04) were associated with efficiency, whereas hematocrit, platelet or leukocyte count, catheter type and patient weight were not. The effect size for predictive factors was small (R(2)=0.21). Adverse events were limited to hypocalcemia. We conclude that female sex, volume processed and CD34+ cell count adversely influence the efficiency of CD34+ cell leukapheresis. However, the impact of volume and CD34+ cell count is small, and likely to be offset by the influence of these same factors on overall yield. Leukapheresis appears to be safe and efficient for autologous blood and marrow transplantation patients with hematocrit >27% and platelet count >30 000/microl.

Antigens, CD34↗
PubMed2002

Diurnal changes in gas exchange and carbon partitioning in needles of fast- and slow-growing families of loblolly pine (Pinus taeda).

We investigated diurnal and seasonal changes in carbon acquisition and partitioning of recently assimilated carbon in fast- and slow-growing families of loblolly pine (Pinus taeda L.) to determine whether fast-growing families exhibited greater carbon gain at the leaf level. Since planting on a xeric infertile site in Scotland County, NC, USA in 1993, five Atlantic Coastal Plain (ACP) and five "Lost Pines" Texas (TX) families have been grown with either optimal nutrition or without fertilization (control). In 1998 and 1999, gas exchange parameters were monitored bimonthly in four families and needles were analyzed bimonthly for starch and soluble sugar concentrations. Although diurnal and seasonal effects on net photosynthesis (A(net)) and maximum rate of light-saturated photosynthesis (A(max)) were significant, few family or treatment differences in gas exchange characteristics were observed. The A(net) peaked at different times during the day over the season, and A(max) was generally highest in May. Instantaneous water-use efficiency (WUE(i)), derived from gas exchange parameters, did not differ among families, whereas foliage stable isotope composition (delta(13)C) values suggested that TX families exhibited lower WUE than more mesic ACP families. Although there were no diurnal effects on foliar starch concentrations, needles exhibited pronounced seasonal changes in absolute concentrations of total nonstructural carbohydrates (TNC), starch and soluble sugars, and in partitioning of TNC to starch and sugars, mirroring seasonal changes in photosynthesis and shoot and root growth. In all families, foliar starch concentrations peaked in May and decreased to a minimum in winter, whereas reducing sugar concentrations were highest in winter. Some family and treatment differences in partitioning of recently assimilated carbon in needles were observed, with the two TX families exhibiting higher concentrations of TNC and starch and enhanced starch partitioning compared with the ACP families. We conclude that growth differences among the four families are not a function of differences in carbon acquisition or partitioning at the leaf level.

Carbohydrates↗
PubMed2002

Totally implanted venous access device removal in interventional radiology.

PURPOSE: To demonstrate that totally implanted venous access device (TIVAD) removal in the out-patient interventional radiology (IR) recovery room is safe and effective. MATERIALS AND METHODS: Fifty-seven TIVADs were removed in 56 patients using a standard cut-down technique. Forty-one devices (72%) in 40 patients without signs of pocket infection were closed with primary intention with sub-cuticular absorbable or simple non-absorbable sutures, depending on operator preference. All patients were followed up to assess for bleeding or infection. Sixteen devices (28%) in 16 patients with suspected pocket infection were allowed to heal by secondary intention. These patients were managed with antibiotics and dressing changes until healing was complete. Catheter tips were sent for culture and sensitivity. RESULTS: TIVADs were removed intact in all 57 cases. There were no cases of air embolism, uncontrolled hemorrhage, retained foreign body or catheter fragmentation. No bleeding or infectious complications were noted in those patients who were allowed to heal with primary intention. Wound closure was accomplished in all patients who were allowed to heal with primary or secondary intention. CONCLUSION: TIVAD removal in an out-patient recovery room by an interventional radiology team is safe and feasible, providing a possible alternative venue for this procedure.

Adult↗
PubMed2001

Pupil block glaucoma in phakic and pseudophakic patients after vitrectomy with silicone oil injection.

PURPOSE: To describe pupil block glaucoma in phakic and pseudophakic patients after vitrectomy with silicone oil injection. DESIGN: Interventional case series. METHODS: Cases were collected from January 1997 to July 2000 from three tertiary referral centers. RESULTS: Seven phakic patients (seven eyes) and one pseudophakic patient (one eye) presented 1 to 90 days after vitrectomy and silicone oil injection with intraocular pressures of 36 to 70 mm Hg. Five patients had an observed or potential weakness of the iris-lens diaphragm. Treatment with Nd:YAG-laser peripheral iridotomy or inferior iridectomy provided a temporary reduction in intraocular pressure for some patients, but all eventually required removal of silicone oil. CONCLUSION: Pupil block glaucoma after silicone oil injection is well recognized in aphakic patients, but ophthalmologists should be aware that it can occur in phakic and pseudophakic patients, particularly in complicated cases and patients with a weakness of the iris-lens diaphragm.

Adult↗
PubMed2001

A randomized, prospective evaluation of the Tesio, Ash split, and Opti-flow hemodialysis catheters.

PURPOSE: A randomized, prospective evaluation of three high-flow hemodialysis catheters. MATERIALS AND METHODS: Ninety-four patients were randomly assigned 113 Tesio, Ash split, and Opti-flow catheters from December 1998 through June 1999. Insertion times, procedural complications, and ease of insertion were recorded. Mean catheter flow rates were recorded at first dialysis, 30 days, and 90 days. Patency, catheter survival, and catheter-related infections were evaluated. RESULTS: Thirty-eight Ash split, 39 Opti-flow, and 36 Tesio catheters were placed. Tesio mean insertion time (41.5 min) was significantly longer than Ash split (29.4 min) or Opti-flow (29.6 min) (P =.004). There were four complications related to Tesio catheters (three cases of pericatheter bleeding, one air embolism), one related to an Opti-flow catheter (pericatheter bleeding), and zero related to Ash split catheters. Opti-flow and Ash split catheters were significantly easier to insert than Tesio catheters (P =.041). Mean flow rates were not significantly different among the catheters initially (P =.112), at 30 days (P =.281), or at 90 days (P =.112). Catheter-related infection rates per 100 catheter days were 0.12 for Ash split, 0.35 for Opti-flow, and 0.14 for TESIO: Median catheter survival was 302 days for Ash split, 176 days for Opti-flow, and 228 days for TESIO: CONCLUSIONS: Opti-Flow and Ash split catheters were faster and easier to place than Tesio catheters. There was no difference in hemodialysis flow rates or catheter survival.

Adult↗
PubMed2001

Pleurx tunneled catheter in the management of malignant ascites.

The authors report their experience with the Pleurx tunneled catheter in patients with end-stage abdominal carcinomatosis and intractable ascites. Ten patients with intractable ascites and abdominal carcinomatosis underwent placement of tunneled Pleurx catheters. The catheters were placed with combined US and fluoroscopic guidance. Patients' charts were reviewed for procedural complications, serum albumin levels, infection, efficacy of catheters in providing effective drainage of ascites, and duration of catheter patency. There were no procedural complications. The serum albumin level decreased from 2.7 g/L to 2.3 at 3 weeks and 2.4 g/L at 6 weeks. There were no catheter infections. Some patients required continuous drainage, whereas others were successfully treated by drainage once per week. Mean catheter survival was 70 days. In patients with end-stage abdominal carcinomatosis complicated by malignant ascites, the Pleurx tunneled catheter can provide effective palliation and alleviated the need for repeated percutaneous paracentesis.

Abdominal Neoplasms↗
PubMed2001

Implementation of strategies to control antimicrobial resistance.

Antimicrobial resistance has emerged as a major public health issue in recent years. A steady increase in resistance continues despite the introduction of new antibiotics, and resistant bacteria have been associated with increased patient morbidity and mortality as well as with increased costs. Addressing the problem of antimicrobial resistance requires both infection control and regulation of antibiotic use; addressing either alone is insufficient. Mounting evidence shows that control of the use of broad-spectrum antibiotics (especially vancomycin and third-generation cephalosporins) and implementation of infection control measures can result in decreased incidence of antibiotic-resistant bacteria such as vancomycin-resistant enterococci and extended-spectrum beta-lactamase-producing Escherichia coli and Klebsiella. Recent reports from professional organizations and a consensus of experts have outlined strategies for the control of resistance in hospitals, with specific measures identified for antibiotic control and infection control. These reports have emphasized the importance of a multidisciplinary approach in tackling this problem in hospitals and have suggested that a quality-improvement model be used to address antimicrobial resistance. A close collaboration among the disciplines of infectious diseases, microbiology, hospital epidemiology, pharmacy, and nursing, with particular emphasis in ICUs, and with strong support from hospital leadership, can result in an effective program that can be readily incorporated into the quality-improvement goals of any health-care organization.

Bacterial Infections↗
PubMed2000

Pyrogenic reactions associated with single daily dosing of intravenous gentamicin.

OBJECTIVE: To identify risk factors associated with an unexpected outbreak of pyrogenic reactions (PR) following intravenous gentamicin. DESIGN: We conducted two cohort studies. PRs were defined as chills, rigors, or shaking within 3 hours after initiating the gentamicin infusion during the preepidemic (December 1, 1997-January 15, 1998) or epidemic (May 1-June 15, 1998) periods. We tested gentamicin vials for endotoxin using the limulus amebocyte lysate assay. SETTING: Inpatient services of a large community hospital in Los Angeles, California. RESULTS: During the epidemic period, 22 (15%) of 152 patients developed documented PRs following intravenous gentamicin. PRs were more likely among patients receiving single daily dosing (SDD) than multiple daily dosing gentamicin (20/73 [27%] vs. 2/79 [3%]; relative risk, 10.8; 95% confidence interval, 2.6 44.7). Laboratory analysis of gentamicin vials found endotoxin levels that were higher among Fujisawa-brand gentamicin (implicated brand) than gentamicin used after the outbreak terminated (non-implicated brand). Although endotoxin levels in the vials did not exceed US Pharmacopeia limits (1.7 endotoxin units/mg gentamicin), the use of SDD gentamicin may place patients at greater risk of receiving doses of endotoxin above the threshold for PRs in humans. CONCLUSIONS: Reassessment of the acceptable amounts of endotoxin in gentamicin and other parenteral products should be considered when dosing intervals used in clinical practice change.

Adolescent↗
PubMed1998

Incidence of post operative wound infection and their antibiogram in a teaching and referral hospital.

A total of 406 post-operative clean wounds were studied for the presence of sepsis and antibiogram of organisms were established. The over all post-operative sepsis rate was 13% (clinical) and 12% (bacteriological). Staphylococcus aureus (32%) and Pseudomonas species (21%) were the commonest organisms recovered and Netilmycin, Cephaloridine and Norfloxacin were the most effective antibiotics against both Gram positive and negative infections. This study reflects the change in pattern of infecting bacterial flora in case of post operative wound infections and its antibiogram.

Adult↗
PubMed1997

Wavelet transform-based image compression for transmission of MR data.

OBJECTIVE: The purpose of this study was to develop an effective, inexpensive teleradiology image-transmission system for transfer of MR studies using wavelet transform image compression. CONCLUSION: We describe an efficient system for implementing teleradiology capability for transmission of diagnostic MR images. The system uses the wavelet transform to achieve greater than 90% image compression, with standard modern transmission times of less than 5 sec per compressed image. The method is inexpensive and can be implemented using commonly available workstation and MR scanner capabilities.

Brain↗
PubMed1996

Effects of carbon dioxide, fertilization, and irrigation on photosynthetic capacity of loblolly pine trees.

Branches of nine-year-old loblolly pine trees grown in a 2 x 2 factorial combination of fertilization and irrigation were exposed for 11 months to ambient, ambient + 175, or ambient + 350 micro mol mol(-1) CO(2). Rates of light-saturated net photosynthesis (A(max)), maximum stomatal conductance to water vapor (g(max)), and foliar nitrogen concentration (% dry mass) were assessed monthly from April 1993 until September 1993 on 1992 foliage (one-year-old) and from July 1993 to March 1994 on 1993 foliage (current-year). Rates of A(max) of foliage in the ambient + 175 CO(2) treatment and ambient + 350 were 32-47 and 83-91% greater, respectively, than that of foliage in the ambient CO(2) treatment. There was a statistically significant interaction between CO(2) treatment and fertilization or irrigation treatment on A(max) on only one measurement date for each age class of foliage. Light-saturated stomatal conductance to water vapor (g(max)) was significantly affected by CO(2) treatment on only four measurement dates. Light-saturated g(max) in winter was only 42% of summer g(max) even though soil water during winter was near field capacity and evaporative demand was low. Fertilization increased foliar N concentration by 30% over the study period when averaged across CO(2) treatments. During the study period, the ambient + 350 CO(2) treatment decreased average foliar N concentration of one-year-old foliage in the control, irrigated, fertilized and irrigated + fertilized plots by 5, 6.4, 9.6 and 11%, respectively, compared with one-year-old foliage in the corresponding ambient CO(2) treatments. The percent increase in A(max) due to CO(2) enrichment was similar in all irrigation and fertilization treatments and the effect persisted throughout the 11-month study period for both one-year-old and current-year foliage.

Journal Article↗
PubMed1996

Levels of vascular endothelial growth factor are elevated in the vitreous of patients with subretinal neovascularisation.

BACKGROUND: Vascular endothelial growth factor (VEGF) has been shown to play a major role in intraocular neovascularisation in ischaemic retinal diseases. Subretinal neovascularisation is an important cause of central visual loss, but little is known about the role of this growth factor in its pathogenesis. The aim of this study was to investigate the possible role of VEGF in the development of subretinal neovascularisation. METHODS: Undiluted vitreous samples were obtained from patients undergoing vitrectomy for removal of non-age-related subfoveal neovascular membranes (SFNM). For comparison vitreous from patients undergoing vitrectomy for idiopathic full thickness macular holes (FTMH) and proliferative diabetic retinopathy (PDR) was used. Indirect enzyme linked immunosorbent assay (ELISA), with an antibody directed against the conserved N-terminal region of human VEGF165, was used to determine vitreous levels of VEGF. The growth factor was also localised in the vitreous of patients with SFNM by western blot analysis. RESULTS: The mean (SE) VEGF concentration in the vitreous of patients with SFNM was 27.78 (2.22) ng/ml (n = 8), FTMH was 16.62 (0.9) ng/ml (n = 18), and PDR was 37.77 (3.28) ng/ml (n = 16). The differences between the PDR group and SFNM group versus the FTMH group were both significant (p = 0.0001 and p = 0.0015) as analysed by the Wilcoxon rank sum test). CONCLUSIONS: Vitreous levels of VEGF are significantly elevated in eyes with non-age-related subretinal neovascularisation compared with eyes with FTMH but not as elevated as in PDR. This suggests that VEGF is involved in subretinal angiogenesis.

Adult↗
PubMed1992

Polyamine levels, ornithine decarboxylase (ODC) activity, and ODC-mRNA expression in normal and cancerous human colonocytes.

Ornithine decarboxylase (ODC) and polyamines (putrescine, spermidine, and spermine) are crucial for cell proliferation. Recently, elevated ODC activity and polyamine levels have been suggested as biological markers for human colon cancer. In this study, we measured ODC activity and the levels of polyamines (putrescine, spermidine, spermine, and cadaverine) and acetyl-putrescine in human colonocytes isolated from cancerous areas compared to the adjacent normal colon tissue. In addition, ODC mRNA expression was compared between both groups. We found that colonocytes isolated from cancerous areas had significantly higher mean value of ODC activity, putrescine, spermidine, spermine, and cadaverine levels up to 1480%, 470%, 260%, 380%, and 510% respectively compared to colonocytes isolated from the adjacent normal colonic mucosa. No difference was found in acetyl-putrescine levels between cancerous and normal colonocytes. Steady-state levels of ODC mRNA were slightly elevated in cancerous colonocytes relative to normal colonocytes in two of three paired samples. However, the increase in ODC mRNA levels is not sufficient to account for the increase in ODC activity suggesting that colonocyte ODC activity is regulated post-transcriptionally.

Adult↗
PubMed1991

Isolation of wound-specific cDNA clones from a cDNA library prepared with mRNAs of alkali-burned rabbit corneas.

Alkali burn is one of the most severe corneal injuries. In order to gain a better understanding of the healing of alkali-burned corneas, it is necessary to identify and characterize proteins that are specifically synthesized by the injured corneal tissues. In this study, we developed a useful procedure to identify and isolate cDNA clones that encode messenger ribonucleic acids (mRNAs) that are specific and/or abundant in alkali-burned rabbit corneas (ARCs), but absent in normal rabbit corneas (NRCs). At first, a cDNA library was prepared by cloning cDNA of mRNA isolated from ARCs into the lambda ORF-8 vector. A differential plaque hybridization was used to screen 2.5 x 10(4) plaque-forming units (pfu) from an ARC cDNA library using 32P-labeled cDNAs prepared from mRNA of ARCs and NRCs. Thirty-seven cDNA clones of mRNAs specific for ARCs were identified and isolated in their pureform. The cDNA inserts of these lambda ORF-8 phages were subcloned into the pSM216 vector by in vivo recombination. The cDNA inserts then were characterized by restriction enzyme digestion, i.e., BamHI, HindIII, and EcoRI. The size of the cDNA inserts ranged from 210 to 5,000 base pairs. Using Northern blot hybridization of total RNA prepared from polymorphonuclear neutrophils, mononuclear leukocytes, alkali-burned corneas, and normal corneas, the cDNA clones were divided into three groups. Five cDNA clones encoded mRNA of corneal cells in ARCs. Twenty-four cDNA clones derived from mRNA of inflammatory cells were present in alkali-burned corneas, but Northern blot hybridization failed to identify mRNA of discrete sizes.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkalies↗
PubMed1990

Pseudoepitheliomatous hyperplasia and pyoderma gangrenosum after a brown recluse spider bite.

Brown recluse spider bites may result in extensive soft tissue injury, causing months of disability. We have described a patient who had a series of extensive surgical debridements after envenomation. Despite skin grafting, persistent cutaneous lesions and extensive satellitosis progressed to involve the entire lower extremity. A recent biopsy showed pseudoepitheliomatous hyperplasia and pyoderma gangrenosum complicating the original injury. Although the role of early surgical excision and newer forms of medical treatment including dapsone and antivenom are still in evolution, recent reports suggest that the majority of patients will respond to medical therapy and may not require any surgical intervention.

Animals↗