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Biomedical subjects

P Kumar

Publications and source records attributed to P Kumar.

At least 73 records · Page 4Linked to original sources
PubMed2001

Treatment of advanced head and neck cancer with intra-arterial cisplatin and concurrent radiation therapy: the 'RADPLAT' protocol.

The prognosis for patients presenting with advanced head and neck squamous cell carcinoma using "standard" treatment approaches, such as surgery followed by radiotherapy or radiotherapy alone, remains poor. Additionally, patients often lose their voice or swallowing ability when a primary surgical approach is used. Although systemic chemotherapy, when combined concurrently with radiotherapy, appears to be superior to radiation alone, the use of neoadjuvant or adjuvant systemic chemotherapy has not improved survival when combined with either surgery or radiotherapy. Even with the use of concurrent systemic chemotherapy and radiotherapy, the majority of the patients still succumb to their disease, usually failing locoregionally. Among the newer strategies being explored is the use of supradose intra-arterial chemotherapy (ie, cisplatin) with current radiotherapy. Acronymed "RADPLAT," this novel therapeutic approach delivers supradoses of weekly cisplatin chemotherapy with concurrent radiotherapy with acceptable toxicity, high locoregional tumor control rates, and very promising survival results. In addition, the RADPLAT approach allows for the preservation of organ function. This article reviews the evolution of the RADPLAT concept from a phase I trial to a recently completed Radiation Therapy Oncology Group trial confirming its feasibility in a multi-institutional setting.

Carcinoma, Squamous Cell↗
PubMed2001

Concomitant off-pump myocardial revascularization and pheochromocytoma resection.

Surgical management of patients with coexisting ischemic heart disease and pheochromocytoma remains challenging. We present one such case in which hybrid myocardial revascularization (angioplasty with stenting and off-pump coronary artery bypass grafting) and resection of pheochromocytoma were undertaken. Unusual features included simultaneous coronary artery surgery and tumor resection and, in particular, coronary artery surgery being performed without cardiopulmonary bypass.

Adrenal Gland Neoplasms↗
PubMed2001

Prevalence and patterns of presentation of genetic disorders in a pediatric emergency department.

OBJECTIVES: To determine the prevalence and patterns of presentation of previously diagnosed and of suspected genetic disorders among pediatric emergency department (ED) visits to a hospital that serves an inner-city population. PATIENTS AND METHODS: A retrospective review of 15,258 pediatric (<18 years old) ED visits at Lincoln Medical and Mental Health Center was undertaken for visits that occurred between October 1998 and February 1999. Suspected genetic disorders, classified into chromosomal, single gene, multifactorial, and other syndromic categories, were recorded. RESULTS: Of 15,258 visits reviewed, 2839 visits (18.6%) were by patients who had known or suspected genetic disorders. Previously diagnosed genetic disorders were documented in 80 visits (2.8%). Of these, 69 visits (86.2%) were related to single gene disorders, 3 (3.8%) to chromosomal disorders, 6 (7.5%) to multifactorial disorders, and 2 (2.5%) to disorders in the "other" category. Of these 80 visits, 59 (74%) were associated with sickle cell disease. The remaining 2759 visits (97.2%) were associated with complaints or diagnoses that suggested the possibility of an underlying genetic disorder requiring further evaluation and diagnostic work-up. CONCLUSIONS: Pediatric patients with known or suspected genetic disorders are frequently treated in EDs. Awareness of underlying genetic disorders facilitates diagnostic evaluation, treatment planning, and referral to a genetics clinic for counseling.

Adolescent↗
PubMed2001

Integrated biological and physiochemical treatment process for nitrate and fluoride removal.

The feasibility of an integrated biological and physiochemical water treatment process for nitrate and fluoride removal has been evaluated. It consisted of two sequencing batch reactors (SBRs) in series. Performance of the process in the treatment of 24 synthetic water samples having nitrate concentrations of 40, 80, 120, 160, 200, and 250 mg/l (as N) and fluoride concentrations of 6, 10, 15, and 20 mg/l at different combinations was studied. Denitrification followed by defluoridation proved to be the best sequence of treatment. In all cases nitrate could be reduced to an acceptable level of less than 10 mg/l (as N) at 3, 5, and 7 h hydraulic retention times (HRTs) depending on its initial concentration. Fluoride concentrations up to 15 mg/l associated with nitrate concentrations up to 80 mg/l (as N) could be reduced acceptable 1.5 mg/l by alum-PAC slurry using alum doses up 850 mg/l [as Al2(SO4)3 x 16H2O] along with 100 mg/l of powdered activated carbon (PAC). Additional alkalinity produced during denitrification was used up during defluoridation for maintenance of pH avoiding the need for lime addition. On the other hand, residual organics, turbidity, and sulfide present in the denitrified water are removed by alum and PAC at the defluoridation stage along with fluoride, eliminating the need for an additional post-treatment step. At higher nitrate concentrations (> or = 120 mg/l as N), the alkalinity produced at the denitrification stage was in the range of 715-1175 mg/l as CaCO3. This excessive alkalinity inhibited reduction of fluoride to the level of 1.5 mg/l at the defluoridation stage, using alum doses up to 900 mg/l along with 100 mg/l of PAC. In all cases a fluoride concentration of 20 mg/l in water could not be reduced to the acceptable level of 1.5 mg/l.

Alum Compounds↗
PubMed2001

Infantile digital fibromatosis - a case report.

Infantile digital fibromatosis (IDF) is a form of fibromatosis usually restricted to childhood. Typically occuring on fingers and toes of children and rarely in the oral cavity [Canioni et al. Pathol. Res. Pract. 187 (1991) 886] and in adults [Viale et al. Histopathology 12 (1998) 415]. It was first described by Reye [Arch. Pathol. Lab. Med. 80 (1965) 228]. IDF (Reyes tumour) is a rarely encountered, non malignant tumour of children. The lesions may be multiple and are either present at birth or appear during the first 2 years of life and are prone for recurrence after removal. Recognition is important as they often regress spontaneously if left alone [Ishi et al. Br. J. Dermatol. 121 (1989) 129]. We report here a care of IDF on right second toe, which was congenital in origin and was clinically similar to keloid.

Fibroma↗
PubMed2001

Acinetobacter baumannii--an emerging nosocomial pathogen in the burns unit Manipal, India.

A retrospective study on 113 patients admitted to the burns unit over a period of 12 months was undertaken to investigate the emerging trend of Acinetobacter baumannii infection. Wound infection with A. baumannii was seen in 13 (11.5%) patients. Of these six (46%) patients developed septicaemia with the same bacteria and five (38%) expired. The virulence of these bacteria, drug susceptibility pattern and its role as a nosocomial pathogen is discussed.

Acinetobacter↗
PubMed2001

High tension electrical injury from a telephone receiver.

A high tension (13000 V) electrical injury to a young man from telephone receiver is described. The current entered the telephone circuit due to contact with a high tension live wire running close to the telephone wire 2 km away from the site of incidence.

Adult↗
PubMed2001

Protective role of L-carnitine on liver and heart lipid peroxidation in atherosclerotic rats.

Lipid peroxides are considered to be the initiation factor for atherosclerosis. Present study depicts that L-carnitine treatment (300 mg/kg body weight/day) for 7 and 14 days caused significant reduction in the tissue lipid peroxidations. It also shows marked improvement in the antioxidant status. By this way carnitine maintain the normal function of the cells.

Journal Article↗
PubMed2001

Influence of swim-up method on the recovery of spermatozoa from different types of semen samples.

PURPOSE: To compare the effectiveness of swim-up method, using different types of semen samples. METHODS: In this retrospective study undertaken in university medical college infertility centre, subfertile couples undergoing Intra Uterine Insemination were selected. A total of 600 semen samples used for the preparation of sperm samples using swim-up method were analyzed. Relative Yield was calculated from the sperm count and motility before and after swim up from each semen sample in six different groups. RESULT(S): Statistically significant increase in relative yield was found in oligospermic samples (20.41) followed by teratospermia (16.98). However, relative yield was low in asthenospermic (11.97) and normal (> 60 million/ml) samples (11.66). CONCLUSION(S): Semen samples with good sperm count resulted in poor recovery after swim up. Swim-up method appears to be effective for oligospermic samples. Modifications like multiple tube swim up, using appropriate incubation time based on the initial semen parameter, will enhance the sperm yield after swim up.

Humans↗
PubMed2001

The expression of Brostm, a KNOTTED1-like gene, marks the cell type and timing of in vitro shoot induction in Brassica oleracea.

We studied the early events of de novo formation of adventitious shoot meristems in stem segments of Brassica oleracea. A regeneration system was used that is efficient, rapid, highly responsive to cytokinins and does not involve callus formation, thus allowing studies on a direct developmental switch of cells in the stem segment to form adventitious shoot meristem cells. Shoot meristem cells and dividing cells were marked from very early stages using in situ hybridization studies with Brostm, a Brassica homologue of the Arabidopsis SHOOTMERISTEMLESS (STM) gene, and a cyclin box-derived probe, Brocyc, respectively. We show that the process of developmental switching starts before any cell division occurs in the stem explants. This switching occurs synchronously both longitudinally and transversely in the explant, in groups of 5-7 phloem parenchyma cells subtending vascular bundles in the explant. Brostm is induced specifically in response to a cytokinin, benzyladenine, within 4 h of treatment and the transcripts persist during cell proliferation leading to shoot differentiation. We also show that during adventitious shoot formation, cells expressing Brostm are distinct from those expressing Brocyc. Lastly, our data suggest that, although developmental switching is initiated synchronously within 4 h of treatment, it requires 8 h of treatment for the establishment of organogenic determinance. The latter process is aynchronous, implying that additional factors formed later than Brostm are required to achieve maximal levels of determined cell populations to form adventitious shoots in vitro.

Adenine↗
PubMed2001

Characterization of Hoxd1 protein-DNA-binding specificity using affinity chromatography and random DNA oligomer selection.

1. Hoxd1 is member of the labial subfamily of Hox genes that has a conserved 60 amino acid homeodomain region. The homeodomain is an important determining factor in the binding of the protein to specific DNA sequence(s). DNA-binding specificity for the Hoxd1 protein has not been determined previously. 2. We have employed a rapid affinity chromatography method to determine optimal DNA binding sequences for the 109 amino acid Hoxd1 peptide, comprising the homeodomain and the entire carboxy terminal region of the Hoxd1 protein. 3. Labial Hox proteins have intrinsically weak DNA-binding activity that has been attributed to the nonbasic residues at positions 2 and 3 in the N-terminal arm of the homeodomain. The presence of the Hoxd1 carboxy terminal region negated the influence of the nonbasic residues and facilitated Hoxd1 DNA-binding specificity. 4. DNA sequences bound to the Hoxd1 peptide-affinity column were separated from a random pool of oligonucleotide sequences by gradient elution and enriched by polymerase chain reaction. Preferred sequences were identified on 5' and 3' of a TAAT core, extending the binding site to T/AT/gTAATTGTA. 5. Stability and specificity of optimal DNA-binding sequence for Hoxd1 homeodomain were determined by equilibrium and kinetic studies. Dissociation coefficient constant (KD) was estimated to be 8.6 x 10(-9) M and the DNA-Hoxd1 homeodomain complex has a half life (t(1/2)) of 12.7 min. 6. A molecular model of Hoxd1 homeodomain-DNA interaction based on the X-ray coordinates of Antennapedia homeodomain-DNA complex has revealed novel interactions of key Hoxd1 residues at the protein-DNA interface.

Amino Acid Sequence↗
PubMed2001

Interleukin-18 induces rheumatoid arthritis synovial fibroblast CXC chemokine production through NFkappaB activation.

Interleukin-18 (IL-18) is a novel proinflammatory cytokine that was recently found in synovial fluids and in synovial tissues from patients with rheumatoid arthritis (RA). To determine the participation of IL-18 in the inflammation observed in RA, we investigated the effect of IL-18 on RA synovial fibroblast chemokine production. Using FACS analysis, we showed that IL-18 induced a doubling in the production of intracellular IL-8 by RA synovial fibroblasts, and this result was confirmed by Western blot. At the extracellular level, IL-18 up-regulated the secretion of IL-8 in a dose- and time-dependent manner. IL-18 also up-regulated the other CXC chemokines, epithelial-neutrophil activating protein (ENA-78) and growth-regulated oncogene (groalpha), in a dose dependent manner, but failed to induce the production of the CC chemokine, macrophage inflammatory protein (MIP)-1alpha. By immunofluorescence and Western blot, we demonstrated that IL-18 activates the translocation of the transcription factor nuclear factor kappa B (NFkappaB) into the nucleus of RA synovial fibroblasts. IL-18 induces IL-8 secretion through NFkappaB because RA synovial fibroblasts pretreated with antisense to NFkappaB p65 oligonucleotide produce a mean of 44% less IL-8 compared with cells pretreated with the control sense oligonucleotide. These results indicate a novel role for IL-18 in inducing RA synovial fibroblast expression of CXC chemokines through NFkappaB and place this cytokine in a strategic role in the local inflammation observed in RA.

Arthritis, Rheumatoid↗
PubMed2001

The utility of plasma polymerase chain reaction for human herpes virus-6 among pediatric bone marrow transplant recipients: results of a pilot study.

We evaluated the utility of plasma polymerase chain reaction (PCR) for surveillance of human herpes virus 6 (HHV-6) infection among pediatric bone marrow transplant (BMT) recipients. We used a prospective, non-interventional design involving a study group and controls. BMT recipients and healthy controls were evaluated. BMT subjects had HHV-6 PCR done biweekly for 12 weeks post transplantation, while a single PCR test was done on controls. For the PCR assay, EDTA blood was collected and DNA extracted from whole blood and cell-free plasma using standard procedures. The PCR was first performed on DNA from whole blood and if a positive result was obtained, the test was repeated on the DNA from the plasma. Thirty BMT recipients (13 autologous and 17 allogeneic) were enrolled, on whom a total of 156 PCR tests were performed, while six tests were done on six healthy controls. The median age of BMT subjects was 6.2 years (range 0.5-17.5 years). The median age of the control subjects was 6.6 years (range 2-10 years). Among asymptomatic BMT patients who had PCR surveillance, the positivity rate was 3.3% (1/30) on whole blood and 0% (0/30) on plasma. None of the six healthy subjects had a positive PCR test on whole blood. During the period of the surveillance study, 14 patients had diagnostic evaluations for HHV-6 disease because of clinical symptoms. Two of these patients were diagnosed with disease associated with HHV-6 (graft failure and encephalitis) and had positive PCR tests on whole blood and plasma and whole blood and cerebrospinal fluid, respectively. We conclude that despite the fact that HHV-6 seropositivity rates are high among children, the frequency of HHV-6 plasma PCR positivity is low in pediatric BMT subjects who are asymptomatic for HHV-6 disease. Given that a positive test on plasma is consistent with active infection, this increases the utility of the PCR test as a diagnostic aid in evaluating syndromes presumed to be due to HHV-6 in pediatric bone marrow transplant recipients.

Adolescent↗
PubMed2001

Role of uppermost superficial surface layer of articular cartilage in the lubrication mechanism of joints.

The uppermost superficial surface layer of articular cartilage, the 'lamina splendens' which provides a very low friction lubrication surface in articular joints, was investigated using atomic force microscopy (AFM). Complementary specimens were also observed under SEM at -10 degrees C without dehydration or sputter ion coating. Fresh adult pig osteochondral specimens were prepared from the patellas of pig knee joints and digested with the enzymes, hyaluronidase, chondroitinase ABC and alkaline protease. Friction coefficients between a pyrex glass plate and the osteochondral specimens digested by enzymes as well as natural (undigested) specimens were measured, using a thrust collar apparatus. Normal saline, hyaluronic acid (HA) and a mixture of albumin, globulin, HA (AGH) were used as lubrication media. The surface irregularities usually observed in SEM studies were not apparent under AFM. The articular cartilage surface was resistant to hyaluronidase and also to chondroitinase ABC, but a fibrous structure was exhibited in alkaline protease enzymes-digested specimens. AFM analysis revealed that the thickness of the uppermost superficial surface layer of articular cartilage was between 800 nm and 2 microm in adult pig articular cartilage. The coefficient of friction (c.f.) was significantly higher in chondroitinase ABC and alkaline protease enzymes digested specimens. Generally, in normal saline lubrication medium, c.f. was higher in comparison to HA and AGH lubrication media. The role of the uppermost, superficial surface layer of articular cartilage in the lubrication mechanism of joints is discussed.

Animals↗
PubMed2001

Mallet deformity in sport.

During a four month period 851 patients presented to the Edinburgh Orthopaedic Trauma Unit with an acute sporting injury. Eighteen (2%) patients had either a soft tissue or bony mallet deformity. Six different sports were identified with rugby accounting for eight of the 18 mallet deformities. All patients were treated with splintage. Fourteen patients returned questionnaires regarding subjective digit function following treatment and nine patients claimed excellent function. The average splinting time for this group was 6 weeks and sports were avoided for an average of 5 weeks. Mallet deformity accounts for a minority of sporting injuries, but excellent functional outcome can be achieved with splintage and avoidance of the causative sport while splinted.

Adolescent↗
PubMed2001

Tolerance and pharmacokinetic interactions of rifabutin and azithromycin.

This multicenter study evaluated the tolerance and potential pharmacokinetic interactions between azithromycin and rifabutin in volunteers with or without human immunodeficiency virus infection. Daily dosing with the combination of azithromycin and rifabutin was poorly tolerated, primarily because of gastrointestinal symptoms and neutropenia. No significant pharmacokinetic interactions were found between these drugs.

Adult↗
PubMed2001

Purification of anthrax edema factor from Escherichia coli and identification of residues required for binding to anthrax protective antigen.

The structural gene for anthrax edema factor (EF) was expressed in Escherichia coli under the control of a powerful T5 promoter to yield the 89-kDa recombinant protein that reacted with anti-EF antibodies. Recombinant EF was purified to homogeneity by a two-step procedure involving metal chelate affinity chromatography and cation-exchange chromatography. From 1 liter of culture, 2.5 mg of biologically active EF was easily purified. This is the first report of purification of anthrax EF from E. coli. EF purified from E. coli was biologically and functionally as active as its Bacillus anthracis counterpart. The recombinant protein could compete with lethal factor for binding to protective antigen. Sequence analysis revealed a stretch of seven amino acids, Val Tyr Tyr Glu Ile Gly Lys, present both in EF (residues 136 to 142) and lethal factor (residues 147 to 153). To investigate the role of these seven residues in binding to protective antigen, the residues were individually mutated to alanine in EF. Mutations in residues Tyr137, Tyr138, Ile140, and Lys142 of EF specifically blocked its interaction with anthrax protective antigen. The adenylate cyclase activity of the mutants remained unaffected. The results suggested that residues Tyr137, Tyr138, Ile140, and Lys142 are required for binding of EF to anthrax protective antigen, which facilitates its entry into susceptible cells.

Adenylyl Cyclases↗