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Biomedical subjects

C Arnold

Publications and source records attributed to C Arnold.

At least 73 records · Page 4Linked to original sources

A simple method for endoscopic placement of a nasoduodenal feeding tube.

The key to short-term enteral feeding in patients with gastroparesis is to deliver the nutrition beyond the pylorus. Endoscopic assisted methods allow the precise placement of the feeding tube to the small bowel. However, the main difficulty in association with these procedures is feeding-tube migration into the stomach during the withdrawal of the endoscope. We have developed an endoscopic method with a high success rate which prevents this problem. A reusable angiocatheter guidewire was threaded through the feeding tube, passing beyond the distal opening prior to the withdrawal of the scope. Counterpressure was applied to the feeding tube during the withdrawal of the endoscope. We have successfully placed feeding tubes in 22 out of 23 patients with no complications.

Endoscopy, Digestive System↗

Bone densitometry in Canadian children 8-17 years of Age.

Normative bone mineral density (BMD) and bone mineral content (BMC) values for the total body (TB), proximal femur (PF), and antero-posterior lumbar spine (LS) were obtained from a large cross-sectional sample of children and adolescents who were 8-17 years of age. There were 977 scans for the TB, 892 for the PF, and 666 for the LS; bone mineral values were obtained using a HOLOGIC QDR 2000 in array mode. Data are presented for the subregions of the PF (femoral neck, trochanter, intertrochanter, and the total region) and for the LS (L1-L4 and L3). Female and male values for the FN, LS (L1-L4), and the TB were compared across age groups using a two-way ANOVA. In addition, we compared the 17-year-old female values to a separate sample of young adult women (age 21). At all these sites, BMC and BMD increased significantly with age. There was no gender difference in TB BMC until age 14 or in TB BMD until age 16, when male values were significantly greater. Females had significantly greater LS BMC at ages 12 and 13, but by age 17 the male values were significantly greater. Females had significantly greater LS BMD across all age groups, however. Males had significantly greater FN BMC and BMD across all age groups. There were no significant differences in BMC or BMD at any sites between the 17- and 21-year-old women.

Adolescent↗

Heteroduplex mobility assay for subtyping HIV-1: improved methodology and comparison with phylogenetic analysis of sequence data.

The feasibility of using DNA heteroduplex mobility analysis (HMA) as a rapid and reproducible method for routine subtyping HIV-1 in clinical specimens was examined by comparison with subtype determination by sequencing in both the gag and env genes. The heteroduplexes formed were examined by conventional polyacrylamide gel electrophoresis (PAGE) and also by electrophoresis in the Pharmacia PhastSystem. The significance of the HMA results was determined by the Kruskal-Wallis test, a non-parametric one way analysis of variance. It was possible to obtain an HMA profile rapidly (1-2 days) using fast PCR conditions and the PhastSystem. The HMA bands were generally sharper and more satisfactory on the Phast gels than on conventional polyacrylamide gels and the use of Phast gels was an improvement over conventional PAGE. Non-B subtype viruses could be distinguished from B subtypes, but it was more difficult to distinguish between the non-B subtypes and to assign a subtype to them. Thus, HMA can be adapted to offer a rapid screening method for HIV-1 subtyping, but sequencing is still necessary to assign a definitive subtype. This reflects the empirical nature of the subtype definitions and the quasispecies nature of the HIV genome population.

DNA, Viral↗

Zygotic lethal mutations with maternal effect phenotypes in Drosophila melanogaster. II. Loci on the second and third chromosomes identified by P-element-induced mutations.

Screens for zygotic lethal mutations that are associated with specific maternal effect lethal phenotypes have only been conducted for the X chromosome. To identify loci on the autosomes, which represent four-fifths of the Drosophila genome, we have used the autosomal "FLP-DFS" technique to screen a collection of 496 P element-induced mutations established by the Berkeley Drosophila Genome Project. We have identified 64 new loci whose gene products are required for proper egg formation or normal embryonic development.

Animals↗

Improving patient education for patients with low literacy skills.

Patients who misunderstand their diagnosis and treatment plans usually exhibit poor compliance. The 90 million adult Americans with low literacy skills struggle to understand such essential health information as discharge instructions, consent forms, oral instructions and drug labels. The Joint Commission on Accreditation of Health Organizations (JCAHO) now requires that instructions be given on a level understandable to the patient. Most physicians tend to give too much information on too high a level for many patients to understand. Physicians who speak in simpler language, repeat their instructions and demonstrate key points, while avoiding too many directives, enhance their patients' understanding. Combining easy-to-read written patient education materials with oral instructions has been shown to greatly enhance patient understanding. To be effective with patients whose literacy skills are low, patient education materials should be short and simple, contain culturally sensitive graphics and encourage desired behavior. Compliance with therapy also may be improved by including family members in the patient education process.

Aged↗

Parent comprehension of polio vaccine information pamphlets.

BACKGROUND: Medical information pamphlets often are written using language that requires a reading level higher than parents of many pediatric patients have achieved. Anecdotal reports suggest that many parents may not readily understand the federally mandated Public Health Service vaccine information pamphlets prepared by the Centers for Disease Control and Prevention (CDC) in 1991. The level at which the pamphlets need to be written for low-reading-level parents is undetermined, as is whether parents reading at higher levels will accept low-reading-level materials. METHODS: To determine whether a simple pamphlet prepared at a low reading level using qualitative and adult education techniques would be preferable to the available CDC polio vaccine information pamphlet, we conducted an integrated qualitative-quantitative study. We compared the parent reading time and comprehension of a simplified pamphlet (Louisiana State University, LSU) comprising 4 pages, 322 words, 7 instructional graphics, and a text requiring a 6th grade reading ability with the equivalent 1991 CDC vaccine information pamphlet comprising 16 pages, 18,177 words, no graphics, and a text requiring a 10th grade reading level. We measured the reading ability of 522 parents of pediatric patients from northwest Louisiana seen at public clinics (81%) and in a private office (19%). Of the entire group, 39% were white, 60% African-American, and 1% Hispanic; the mean age was 29 years; the mean highest grade completed was 12th grade 3 months; and the reading level was less than 9th grade in 47% of parents and less than 7th grade in 20%. After parents were given one of the pamphlets to read, their reading time, comprehension, and attitude toward the pamphlet were measured. RESULTS: Mean comprehension was 15% lower for CDC than for LSU (56% vs 72% correct; P < .001) and reading time was three times longer for CDC than for LSU (13 minutes 47 seconds vs 4 minutes 20 seconds; P < .0001). These trends were significant for parents reading at all but the lowest levels. Mean comprehension and reading time did not differ among parents reading at the third grade level or less. However, mean comprehension was greater and reading time lower for LSU among parents at all reading abilities greater than the third grade. Parents in the private practice setting took the longest time to read the CDC (20 minutes 59 seconds vs 5 minutes 46 seconds, LSU), yet their comprehension on the LSU was significantly higher than on the CDC (94% vs 71%; P < .0001). Two focus groups of high-income parents were unanimous in preferring the LSU. CONCLUSIONS: A short, simply written pamphlet with instructional graphics was preferred by high- and low-income parents seen in private and public clinics. The sixth grade reading level appears to be too high for many parents in public clinics; new materials aimed at third to fourth grade levels may be required. The new 1994 CDC immunization materials, written at the eighth grade level, may still be inappropriately high. The American medical community should adopt available techniques for the development of more effective patient-parent education materials.

Adolescent↗

Evaluation of oxygen delivery with the use of nasopharyngeal catheters and nasal cannulas.

The purpose of this pilot study was to examine the differences between nasopharyngeal catheter and nasal cannula oxygen delivery systems in infants. Eleven subjects requiring supplemental oxygen were enrolled in the study. All infants received both therapies at three separate gas flow rates (0.5, 0.3, and 0.2 liters per minute). Infants had higher heart rates when receiving nasal cannula oxygen than when receiving nasopharyngeal catheter oxygen (p < .05). There were no significant differences between the two therapies when comparing pulmonary mechanics, hypopharyngeal oxygen concentrations, and respiratory rates. However, when oxygen was delivered at the higher flow (0.5 liters), heart rate, tidal volume, and oxygen concentration were higher, and respiratory rates were decreased for both methods (p < .05). Because minimal differences were found between these two methods, either may be an appropriate choice for delivering supplemental oxygen.

Heart Rate↗

The management of rheumatoid nodules.

Rheumatoid nodules are present in approximately 25% of patients with seropositive rheumatoid arthritis (RA) and are the most common extra-articular lesions of this disease. Current methods of treatment include a variety of antirheumatic agents, surgical excision, or observation. Treatment options for the rheumatoid nodule are limited, due in part to the highly variable nature of the nodule. This series describes 4 seropositive RA patients, all with extensive rheumatoid nodules. Three were successfully treated by surgical excision, and 1 was successfully treated with conservative management. Surgical treatment is effective. Indications include local pain, nerve compression, limited range of motion, erosion, and infection.

Aged↗

[Cilazapril replacing captopril in the therapy of medium-severe essential hypertension].

Authors performed an open, crossover, multicenter study of oral cilazapril versus previous captopril treatment in mild to moderate hypertension. The treatment of the 100 outpatients on daily three or four times captopril was found ineffective, or in some cases side effects or non compliance necessitated a switch to a once daily dose of cilazapril. Reasons of ineffectivity were compliance problems in 76% of the patients during long term captopril therapy. Blood pressure decreased from 163.28 +/- 14.5/97.5 +/- 9.35 mmHg on captopril therapy to 136.67 +/- 12/83.49 +/- 7.77 mmHg at the end of a 12 week cilazapril treatment (p < 0.001). 80 patients received cilazapril monotherapy (with doses of 2.5 mg in 54 cases, 5 mg in 18 patients). 7.5 mg in 4 cases, 1 and 1.25 mg in 2 patients. In 20 patients an adjunctive diuretic was also added, while the cilazapril treatment was ineffective in 3 patients. In respect of the global evaluation and scoring of cilazapril versus captopril therapy, a clear and statistically significant improvement could be demonstrated in efficacy, tolerability and compliance after a 12 week cilazapril treatment. The 24 hour ambulatory blood pressure measurement performed in 13 patients also verified a decrease in blood pressure achieved by cilazapril therapy. Authors conclude that in case of ineffectivity of three or four times daily captopril treatment (caused most likely by non-compliance), a switch to a once daily dose drug like cilazapril is indicated.

Administration, Oral↗

Sequence distances between env genes of HIV-1 from individuals infected from the same source: implications for the investigation of possible transmission events.

Previously described transmission studies have shown that HIV strains isolated from individuals infected from a common source are more homogeneous than HIV strains isolated from individuals with unrelated infections. This has been the basis, in at least four instances, for deciding whether apparently epidemiologically related cases represent actual transmissions. To date, HIV transmission studies have usually included sequence data from the most likely source of infection, and the probability of transmission from the donor to the recipient has been assessed by measuring sequence similarity against control data using likelihood analysis. We have recently studied a putative transmission involving a UK health care worker (CPHL1), a patient of CPHL1 (CPHL2), and CPHL3, a member of the same "sex circle" as CPHL2. We have used sequence distance and neighbour joining methods as well as likelihood analysis as means of determining genetic relatedness. Though no other source of infection was available our findings did not support the possibility that CPHL1 had infected CPHL2. Strain CPHL3 was closer to CPHL2 than to CPHL1. It is shown that control data from documented transmission events can be used to establish the source of infection in the absence of an index case. It is also shown that the C2-V3 region analysed in previous transmission studies is unreliable for accurate phylogenetic analysis. The results indicated that gp120 is a more informative region than C2-V3 for molecular transmission studies. Sequence distances between the env genes of related and unrelated infections have been derived in this work.

Acquired Immunodeficiency Syndrome↗

Complete nucleotide sequence of the herpesvirus simiae glycoprotein G gene and its expression as an immunogenic fusion protein in bacteria.

The nucleotide sequence of a 2384 bp portion within the unique short (Us) region of the herpesvirus simiae (simian herpes B virus; SHBV) genome is presented. A partial and a complete open reading frame (ORF) were found within this nucleotide sequence. The partial ORF encodes the C terminus (147 amino acids) of a protein kinase which is highly conserved in the herpes simplex virus type 1 (HSV-1) and type 2 (HSV-2) and simian agent 8 (SA8) Us regions. The complete ORF is located 3' to the partial ORF within the 2384 bp sequence and encodes a 593 amino acid glycoprotein which appears to be closely related to the SA8 glycoprotein G (gG), but shares little amino acid similarity with gG of HSV-1 and -2. However, the complete ORF shares certain features conserved among most alphaherpesvirus gGs, notably three highly conserved cysteine residues and an adjacent N-glycosylation site. Therefore, it was concluded that this complete ORF encodes the SHBV gG. The 358 amino acid C-terminal portion of SHBV gG was expressed in Escherichia coli as a fusion protein and this was detected by immunoblotting with sera from cynomolgus monkeys which were either experimentally or naturally infected with SHBV. The purified fusion protein was inoculated into rabbits to raise an antiserum which recognized a number of apparently SHBV gG-specific protein bands in extracts from SHBV-infected simian cells.

Amino Acid Sequence↗

Identification and characterization of monoclonal antibodies specific for polymorphic antigenic determinants within the V2 region of the human immunodeficiency virus type 1 envelope glycoprotein.

We have identified six monoclonal antibodies (MAbs) mapping to both linear and conformation-dependent epitopes within the V2 region of the human immunodeficiency virus type 1 clone HXB10. Three of the MAbs (12b, 66c, and 66a) were able to neutralize the molecular clones HXB10 and HXB2, with titers in the range of 9.5 to 20.0 micrograms/ml. MAbs mapping to the crown of the V2 loop (12b, 60b, and 74) bound poorly to cell surface-expressed oligomeric gp120, suggesting an explanation for the poor or negligible neutralizing activity of MAbs to this region. In contrast, MAbs 12b and 60b demonstrated good reactivity with recombinant gp120 in an enzyme-linked immunosorbent assay format, suggesting differential epitope exposure between the recombinant and native forms of gp120. Cross-competition analysis of these MAbs and additional V1V2 MAbs for gp120 binding enabled us to assign the MAbs to six groups (A to F). Selection of neutralization escape mutants with MAbs 10/76b and 11/68b, belonging to nonoverlapping competition groups, identified amino acid changes at residues 165 (I to T) and 185 (D to N), respectively. Interestingly, these escape variants remained sensitive to neutralization by the nonselecting V2 MAbs. All MAbs demonstrated good recognition of IIIB viral gp120 yet failed to neutralize nonclonal stocks of IIIB. In addition, MAbs 12b and 62c bound MN and RF viral gp120, respectively, yet failed to neutralize the respective isolates. Cloning and expression of a library of gp120 and V1V2 fragments from IIIB-, MN-, and RF-infected H9 cultures identified a number of polymorphic sites, resulting in antigenic variation and subsequent loss of V2 MAb recognition. In contrast, the V3 region from the clones of the same isolates showed no amino acid changes, suggesting that the V2 region is polymorphic in long-term-passaged laboratory isolates and may account for the reduced antibody recognition observed.

Amino Acid Sequence↗

Differential expression of laminin isoforms and alpha 6-beta 4 integrin subunits in the developing human and mouse intestine.

The intestinal tissue is characterized by important morphogenetic movements during development as well as by a continuous dynamic crypt to villus epithelial cell migration leading to differentiation of specialized cells. In this study, we have examined the spatio-temporal distribution of laminin A and M chains as well as of alpha 6 and beta 4 integrin subunits in adult and developing human and mouse intestine by indirect immunofluorescence. Selective expression of the constituent polypeptides of laminin isoforms (A and M chains) was demonstrated. In the mature human intestine, A and M chains were found to be complementary, the M chain being restricted to the base of crypts and the A chain lining the villus basement membrane. In the developing human intestine, M chain expression was delayed as compared to that of A chain; as soon as the M chain was visualized, it exhibited the typical localization in the crypt basement membrane. A somewhat different situation was found in the adult mouse intestine, since both M and A chains were found in the crypts. During mouse intestinal development the delayed expression of the M chain as compared to that of the A chain was also obvious. The absence of M chain expression in mutant dy mouse did not impair intestinal morphogenesis nor cell differentiation. The expression of alpha 6 and beta 4 subunits was not coordinated. In both species the alpha 6 expression preceded that of beta 4. Furthermore, while beta 4 staining in adult mouse intestine was detected at the basal surface of all cells lining the crypt-villus, that of alpha 6 was mainly confined to the crypt cell compartment. An overall similarity of location between alpha 6 integrin subunit and laminin A chain at the epithelial/stromal interface was noted. These data indicate that the spatial and temporal distribution of laminin variants in the developing intestine may be characteristic for each species and that interactions of laminin variants with particular receptors may be important for induction and/or maintenance of differentiated cells.

Adult↗

Day care attendance and other risk factors for invasive Haemophilus influenzae type b disease.

Two hundred and ninety-five of 373 (79%) children with reported cases of invasive Haemophilus influenzae type b (Hib) occurring in the state of Oklahoma from January 1, 1986, through December 31, 1987, were matched according to birth date with two controls each. Conditional logistic regression was used to assess the independent roles of day care attendance, number of young children in the home, crowding, passive smoking, maternal education, household income, and race in Hib disease. Statistically significant odds ratios (ORs) were found for day care attendance (OR = 2.9), the presence of two or more children in the home under 6 years of age (OR = 2.4), crowding (ratio of number of people in the home to number of bedrooms > or = 2) (OR = 2.0), and exposure to cigarette smoking in the home (OR = 1.4). Household income was independently associated with Hib disease. African Americans were at increased risk even after adjustment for income and crowding (OR = 4.1). Although there were no important differences in risk for other factors by type of Hib disease, there was a large and statistically significant difference in risk for day care attendance between meningitis (adjusted OR = 5.1, 95% confidence interval (CI) 3.1-8.2) and other types of Hib disease (combining nonmeningitis cases, adjusted OR = 1.6, 95% CI 0.9-2.7). Increasing numbers of hours per week of day care attendance and children per room were associated with increasing risk of Hib meningitis in a dose-response pattern. The highest day care ORs for meningitis were observed in the youngest (< 6 months) and oldest (> or = 24 months) children. The adjusted OR for exposure to breast feeding was 0.5 (95% CI 0.3-0.8). A protective effect for Hib polysaccharide vaccination among children aged > or = 18 months was suggested but did not reach statistical significance (OR = 0.4, 95% CI 0.2-1.1).

Bacterial Vaccines↗

Transcriptional activation of the macrophage colony-stimulating factor gene by IL-2 is associated with secretion of bioactive macrophage colony-stimulating factor protein by monocytes and involves activation of the transcription factor NF-kappa B.

Human peripheral blood monocytes (Mo) constitutively display the beta-chain of the receptor for IL-2, whereas expression of the IL-2R alpha-chain is not constitutive but inducible with IL-2. Here we report that binding of human IL-2 to its binding site leads to transcriptional activation of the macrophage CSF (M-CSF) gene in Mo resulting in accumulation of M-CSF mRNA and subsequent release of bioactive M-CSF protein as demonstrated by ELISA and inhibition of IL-2 induced release of an activity-stimulating growth of monocyte-type colonies by a neutralizing anti-M-CSF antibody. Transcriptional activation of the M-CSF gene by IL-2 is preceded by enhanced binding activity of the transcription factor NF-kappa B to its recognition sequence in the 5' regulatory enhancer region of the M-CSF gene. Moreover, using a heterologous promoter (herpes thymidine kinase) construct containing the NF-kappa B consensus sequence, it is shown that NF-kappa B binding by an IL-2-induced monocyte-derived nuclear protein confers reporter gene (human growth hormone) activity. Taken together, our findings indicate that IL-2 induces gene expression of M-CSF in human blood-derived Mo and provide evidence for involvement of NF-kappa B in transcriptional regulation of this gene.

Animals↗