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Biomedical subjects

R Moore

Publications and source records attributed to R Moore.

At least 91 records · Page 5Linked to original sources

Topographical variation in the catabolism of aggrecan in an ovine annular lesion model of experimental disc degeneration.

An established model of experimental disc degeneration (Osti et al., Spine 15:762, 1990; Melrose et al., J Orthop Res 10:655, 1992) was used in this study. Four 2-year-old sheep received anterolateral incisions (4 x 10 mm) in the outer one-third of the annulus fibrosus of their L2-L3 and L4-L5 discs (lesion group). The annulus was not incised in another four sham-operated animals. After 6 months the sheep were killed, lumbar discs were dissected into lateral halves of the annulus fibrosus and the nucleus pulposus. Cells were isolated from disc tissues enzymatically and were grown in alginate bead culture to examine the proteoglycan metabolism of cells from lesion and control zones. The media of lesion zone cultures contained relatively high levels (compared with sham cultures) of catabolic fragments of the large, high-buoyant-density proteoglycans as demonstrated by Western blotting using monoclonal antibodies (5-D-4, 3-B-3, 1-C-6) and biotinylated hyaluronan and also by gel chromatography. Furthermore, cells from the vicinity of the lesion site also synthesized significantly lower levels (compared with sham cultures) of aggrecan that was retained within the alginate beads. Collectively, these data indicated that focal depletion of large, high-buoyant-density proteoglycans was evident within lesion sites in this model of experimental disc degeneration. The introduction of an annular lesion therefore significantly affected the proteoglycan metabolism of endogenous disc cell populations. The unique hydrodynamic and viscoelastic properties of the intervertebral disc are dependent to a large degree on the tissue levels of aggrecan. The focal depletion of aggrecan by annular lesions therefore may represent an important predisposing factor to the subsequent degeneration of these intervertebral discs.

Aggrecans↗

Abdominal wall hernia in autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is a common cause of renal impairment with a number of well recognized extrarenal associations. A high incidence of abdominal wall hernia was noted in patients with ADPKD. METHODS: A retrospective review of the notes of all patients with ADPKD on the South Wales renal replacement therapy database was performed. These patients were compared with age- and sex-matched patients with renal failure but without ADPKD and with general surgical patients. RESULTS: The prevalence of hernia in patients with ADPKD was 38 of 85 (45 per cent) compared with seven of 85 (8 per cent) for other forms of renal failure and three of 85 (4 per cent) for general surgical controls (P < 0.001). There were significantly greater numbers of inguinal (P < 0.001), incisional (P = 0.019) and paraumbilical (P = 0.007) hernias in patients with ADPKD compared with the other two groups. CONCLUSION: These results show a significantly greater incidence of hernia, which could be an additional manifestation of the underlying defect in extracellular matrix production identified in patients with ADPKD.

Adult↗

Imagery and hypnosis in the treatment of cancer patients.

Many patients with cancer often seek some means of connecting their mental activity with the unwelcome events occurring in their bodies, via techniques such as imagery and hypnosis. Hypnosis has been shown to be an effective method for controlling cancer pain. The techniques most often employed involve physical relaxation coupled with imagery that provides a substitute focus of attention for the painful sensation. Other related imagery techniques, such as guided imagery, involve attention to internally generated mental images without the formal use of hypnosis. The most well-known of these techniques involves the use of "positive mental images" of a strong army of white blood cells killing cancer cells. Despite claims to the contrary, no reliable evidence has shown that this technique affects disease progression or survival. Studies evaluating more broadly defined forms psychosocial support have come to conflicting conclusions about whether or not these interventions affect survival of cancer patients. However, 10-year follow-up of a randomized trial involving 86 women with cancer showed that a year of weekly "supportive/expressive" group therapy significantly increased survival duration and time from recurrence to death. This intervention encourages patients to express and deal with strong emotions and also focuses on clarifying doctor-patient communication. Numerous other studies suggest that suppression of negative affect, excessive conformity, severe stress, and lack of social support predict a poorer medical outcome from cancer. Thus, further investigation into the interaction between body and mind in coping with cancer is warranted.

Attitude to Health↗

Congenital pseudarthrosis of the tibia treated with free vascularized fibular graft.

Management of patients with deformities due to congenital pseudarthrosis of the tibia continues to be controversial. The use of free vascularized fibular grafts in the reconstruction of these deformities appears to be successful in this patient population but is not without potential for significant complications. Long-term evaluation, at least to skeletal maturity, is necessary to judge the success of any procedure done for any pediatric patient. This case illustrates the natural history of the vascularized free fibular graft for congenital pseudarthrosis of the tibia in a young child. Complications of this treatment modality did occur, including probable recurrence and fracture at almost 11 years post-index procedure. However, stable reconstruction leading to fracture union was achieved, and the patient has resumed full activities with little residual deformity.

Adolescent↗

Mouse decay-accelerating factor: selective and tissue-specific induction by estrogen of the gene encoding the glycosylphosphatidylinositol-anchored form.

Neonatal exposure of mice to estrogen (diethylstilbestrol) results in a high incidence (90%) of uterine tumor later in life. In an effort to screen for estrogen-regulated genes in the uterus of the neonatal mouse, we have isolated a murine homologue of the human decay-accelerating factor (DAF), a glycosylphosphatidylinositol (GPI)-anchored membrane glycoprotein and a member of the regulators of complement activation family of proteins that function to prevent autologous complement-mediated tissue damage. The induced mouse DAF cDNA has a 64% sequence identity with the human counterpart at the nucleotide level and a 50% identity in the deduced amino acid sequence. It consists of 390 amino acids and contains four short consensus repeats of internal homology characteristic of human DAF. It also contains a hydrophobic C-terminal that most likely serves as a signal for GPI anchor attachment. Sequence comparison with the recently reported mouse DAF cDNAs confirmed that the estrogen-inducible gene corresponds to the mouse GPI DAF gene. The induction of mouse DAF by estrogen is tissue specific and can be mimicked by the antiestrogen tamoxifen. Furthermore, the regulation of uterine DAF expression by estrogen is limited to the GPI DAF gene. The transmembrane DAF gene is not expressed in the mouse uterus, either with or without estrogen stimulation. These results suggest that the two mouse DAF genes are differentially regulated, and that the GPI-anchored DAF may play important roles in estrogen responses and other physiologic or pathophysiologic processes of the female reproductive system.

Amino Acid Sequence↗

Characterization of phenobarbital-inducible mouse Cyp2b10 gene transcription in primary hepatocytes.

The mouse phenobarbital (PB)-inducible Cyp2b10 gene promoter has been isolated and sequenced, and control of its expression has been characterized. The 1405-base pair (bp) Cyp2bl0 promoter sequence is 83% identical to the corresponding region from the rat CYP2B2 gene. In addition to the lack of CA repeats, differences include insertion of 42 base pairs (-123/-82 bp) into the middle of a consensus sequence to the so-called "Barbie box." In this report, we have developed a primary mouse hepatocyte culture system in which endogenous 2B10 mRNA as well as Cyp2b10-driven CAT activity were induced by PB and 1,4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP), but not by the 3-chloro derivative of TCPOBOP. Deletion analysis of the Cyp2b10 promoter identified a basal transcription element at -64/-34 bp and a negative element at -971/-775 bp. Sequences contained within the -1404/-971 bp region are responsible for the induced CAT activity. DNase I protection and gel shift assays detected five major protein binding sites within the -1404/-971 bp fragment, one of which shared high sequence identity with a portion of a regulatory element in CYP2B2 gene (Trottier, E., Belzil, A., Stoltz, C., and Anderson, A. (1995) Gene 158, 263-268). Our results indicate that sequences important for PB-induced transcription of Cyp2b10 gene are located in the distal promoter.

Animals↗

Pharmacokinetics and immunodynamics of chimeric IL-2 receptor monoclonal antibody SDZ CHI 621 in renal allograft recipients.

SDZ CHI 621 is a murine-human chimeric monoclonal antibody (mAb) to the interleukin-2 (IL-2) receptor (CD25) intended for prophylactic immunosuppression against acute rejection in the first several weeks following kidney transplantation. A multicentre, prospective, dose-finding study was conducted in 37 primary, mismatched cadaver kidney transplant patients to assess its tolerability, pharmacokinetics and immunodynamics. Successive cohorts of patients were stratified to receive total doses of 20, 30, 40 or 60 mg (n = 4, 4, 14, 15, respectively) administered as 15- or 20-mg intravenous infusions with the first dose given preoperatively and subsequent doses within the first 10 days posttransplant. Daily mAb serum concentrations were analysed by a radioimmunoassay method and the percentage of peripheral T-lymphocytes expressing CD25 from serial blood samples was determined by FACScan. Intravenous administrations were well tolerated. mAb concentration profiles exhibited a biphasic decline with an initial t1/2 of 14.4 +/- 14.2 h, terminal t1/2 of 13.4 +/- 6.0 days, distribution volume (Vss) of 6.9 +/- 3.31 and clearance of 17.4 +/- 7.8 ml/h. The concentration-effect (mAb-CD25) relationship indicated that mAb concentrations exceeding a threshold of about 0.7 microgram/ml corresponded to complete suppression of CD25 (< or = 3% CD25+ T-cells). The threshold mAb concentration was exceeded at all dose levels, whereas the duration above the threshold (and thus of CD25 suppression) rose with increasing dose: 20 mg, 20 +/- 7 days; 30 mg, 32 +/- 6 days; 40 mg, 37 +/- 10 days; and 60 mg, 53 +/- 17 days. As mAb concentrations declined below the threshold following the last dose, CD25 expression returned to baseline (18-44% CD25+ T-cells) within a few days.

Adolescent↗

Laparoscopic complications in markedly obese urologic patients (a multi-institutional review)

OBJECTIVES: Significant obesity is considered to be a relative contraindication to laparoscopic surgery. This study reviews the complications encountered in massively obese patients undergoing urologic laparoscopic surgery. METHODS: Body mass index (BMI) was used as an objective index to indicate massive obesity. Eleven institutions compiled retrospective data on 125 patients having a BMI greater than 30. Procedures performed included 76 pelvic lymph node dissections, 14 nephrectomies, 7 bladder neck suspensions, and 28 miscellaneous procedures. RESULTS: For the group as a whole, the mean BMI was 35.1 (range 30.1 to 57.2). Mean operative time was 202 minutes (range 60 to 480). Conversion to open surgery occurred in 15 of the 125 patients (12%). Complication rates (minor and major) were 22% (27 occurrences in 125 patients) intraoperatively and 26% (33 occurrences in 125 patients) postoperatively. The major complications included 2 trocar injuries to abdominal wall vessels, 1 bladder injury, 3 peripheral nerve injuries, 1 dysrhythmia, 1 deep vein thrombosis, 1 wound seroma, 1 nephrocutaneous fistula, 1 incisional hernia, and 1 death. CONCLUSIONS: In this review, complication rates for urologic laparoscopic surgery on massively obese patients were higher than in the general population undergoing laparoscopic surgery (0.3% to 21%).

Adolescent↗

Fear of injections and report of negative dentist behavior among Caucasian American and Taiwanese adults from dental school clinics.

Fear of injections and reports of negative dentist behavior and associations with dental anxiety and avoidance of treatment were explored among 951 adults from dental school clinics in Iowa City, Iowa and Taipei, Taiwan. Use and fear of anesthetic injections and negative dentist behavior were assessed by written questionnaire to test associations with demographics, overall dental anxiety (Dental Anxiety Scale or "DAS") and utilization behaviors. Frequency and logistic regression analyses showed that use of dental anesthetics for routine treatment was much greater overall among caucasian Americans than Taiwanese, as was fear of injections. Taiwanese and Americans with high dental anxiety (DAS 12) had similar high fear of injections, but inspite of similar fears about dental drilling, high anxiety Taiwanese reported using much less local anesthesia for routine treatments than did high anxiety Americans. Report of condescending remarks to patients ("put downs") by dentists was mainly an American phenomenon associated with high dental anxiety. Avoidance of appointment making was high for persons afraid of injections and for Americans reporting negative dentist behavior. Avoidance was highest in subjects with high dental anxiety. That predominant characteristics or etiologies of dental anxiety can differ by cultural differences in dental health care systems, dentist beliefs and/or expectations of patients within those systems was discussed in relation to the literature.

Adolescent↗

Translocation of Shiga toxin across polarized intestinal cells in tissue culture.

Escherichia coli strains producing Shiga toxins (Stx) 1 and 2 colonize the lower gastrointestinal tract in humans and are associated with gastrointestinal and systemic diseases. Stx are detectable in the feces of infected patients, and it is likely that toxin passes from the intestinal tract lumen to underlying tissues. The objective of this study was to develop an in vitro model to study the passage of Stx across intact, polarized cell monolayers. Translocation of biologically active Stx was examined in four cell lines grown on polycarbonate filters. Stx1 translocated across intestinal cell monolayers (CaCo2A and T84 cells) in an energy-requiring and saturable manner, while the monolayers maintained a high level of electrical resistance. Stx1 had no effect on electrical resistance or inulin movement across these cell lines for at least 24 h. Induction of specific Stx receptors with sodium butyrate reduced the proportion of toxin translocated across CaCo2A monolayers but had no major effect on the movement of horseradish peroxidase or [3H]inulin. We have shown that biologically active Stx1 is capable of moving across intact polarized intestinal epithelial cells without apparent cellular disruption, probably via a transcellular pathway. The data also suggest that the presence of Stx receptors on the apical surface of intestinal epithelial cells may offer some protection against the absorption of luminal Stx1.

Animals↗

Necropsy findings in lysinuric protein intolerance.

Lysinuric protein intolerance (LPI) is a rare autosomal recessive inborn error of metabolism, characterised by defective transport of the cationic amino acids lysine, arginine and ornithine. To date there are few reported necropsy cases. This report describes the necropsy findings in a 21 year old female patient originally diagnosed as having LPI in 1973. Liver function tests deteriorated and immediately before death jaundice, hyperammonaemia, coma, metabolic acidosis, and a severe bleeding diathesis developed. At necropsy, there was micronodular cirrhosis of the liver with extensive fatty change in hepatocytes. The lungs showed pulmonary alveolar proteinosis. Immunofluorescence and electron microscopy revealed the presence of a glomerulonephritis with predominant IgA deposition. These necropsy findings reflect the spectrum of lesions reported in LPI, providing further evidence of an association between this condition and pulmonary alveolar proteinosis, cirrhosis and glomerulonephritis.

Adult↗

The sternalis muscle: an unusual normal finding seen on mammography.

OBJECTIVE: We studied the appearance of the sternalis muscle on mammography and on CT and MR imaging. To our knowledge, this is the first description of this normal anatomic variant. An approach is provided that permits differentiation of the sternalis from significant pathology. SUBJECTS AND METHODS: Between January 1992 and December 1994, four women of an estimated 32,000 who had mammograms at the Massachusetts General Hospital had an unusual, irregular structure visible medially on the craniocaudal projection that posed a diagnostic dilemma. The records and imaging studies of these women and two others from the Deaconess Hospital breast imaging program were reviewed to determine the etiology of the findings seen by mammography and to establish a diagnostic approach. RESULTS: Surgery in one patient and cross-sectional imaging in the other five established that the structure was the sternalis muscle. Although it may be bilateral, the sternalis muscle was visible only unilaterally on the mammograms of these six women. The appearance of the muscle ranged from an irregularly rounded density at the sternal edge of the film to flame-shaped and almost completely surrounded by fat. CT and MR imaging are diagnostic when they show the longitudinal extent of the muscle, which lies anterior to the medial margin of the pectoralis major muscle. CONCLUSION: The sternalis muscle is an unusual variant of the chest wall musculature. It may be visible as a rounded or irregular density on the craniocaudal mammogram along the sternal edge of the film. With improved mammographic positioning it will be seen more frequently. The muscle has a variety of appearances that should be familiar to the radiologist to avoid confusion with a malignant lesion. The etiology can be confirmed and cancer excluded by CT or MR imaging.

Adult↗

Maternal plasma human immunodeficiency virus type 1 RNA level: a determinant and projected threshold for mother-to-child transmission.

To prevent mother-to-child human immunodeficiency virus type 1 (HIV-1) transmission, it is important to identify its determinants. Because HIV-1 RNA levels can be reduced by antiviral therapy, we examined the role of maternal plasma HIV-1 RNA level in mother-to-child transmission. We used quantitative competitive PCR to measure HIV-RNA in 30 infected pregnant women and then followed their infants prospectively; 27% of the women transmitted HIV-1 to their infants and maternal plasma HIV-1 RNA level correlated strikingly with transmission. Eight of the 10 women with the highest HIV-1 RNA levels at delivery (190,400-1,664,100 copies per ml of plasma) transmitted, while none of the 20 women with lower levels (500-155,800 copies per ml) did (P = 0.0002). Statistical analysis of the distribution of HIV-1 RNA loads in these 30 women projected a threshold for mother-to-child transmission in a larger population; the probability of a woman with a viral RNA level of < or = 100,000 copies per ml not transmitting is predicted to be 97%. Examination of serial HIV-1 RNA levels during pregnancy showed that viral load was stable in women who did not initiate or change antiviral therapy. These data identify maternal plasma HIV-1-RNA level as a major determinant of mother-to-child transmission and suggest that quantitation of HIV-1 RNA may predict the risk of transmission.

Acquired Immunodeficiency Syndrome↗

Prolonged action of a chimeric interleukin-2 receptor (CD25) monoclonal antibody used in cadaveric renal transplantation.

A high affinity chimeric CD25 mAb (chRFT5: SDZ CHI 621) blocking interleukin-2 binding to the interleukin-2 receptor alpha-chain was evaluated in a phase I/II study in human renal cadaveric transplantation. The chRFT5 was well tolerated with no immediate adverse effects during 6 spaced infusions (from before transplantation to day 24) in 24 patients escalating from 2.5- to 25-mg dosages. The chRFT5 had a long terminal half-life with a mean of 13.1 days. There was good correlation between the detection of chRFT5 in the serum by radioimmunoassay, the coating and suppression of CD25 on T cells, and antibody activity in patient serum samples. The chRFT5 activity persisted in vivo for up to 120 days. No antibody response to the chRFT5 was detected in any of the patients, even though two patients who required treatment with antithymocyte globulin or OKT3 developed xenogeneic antiglobulin responses while chRFT5 was still present in vivo. There was a 33% incidence of rejection and the first rejection episode always occurred during chRFT5 therapy. Patients who did not reject during therapy did not reject during the first year following transplantation. Equal numbers of patients received dual and triple immunosuppressive therapy together with chRFT5. Posttransplant lymphoproliferative disorder developed in 2 patients, both on triple therapy, at 9 months after transplantation. The disorder did not develop in any patient receiving dual therapy, and no further cases have been observed to a minimum of 2 years' follow-up. No other viral, fungal, or bacterial infectious complications were prevalent in patients treated with chRFT5.

Adult↗