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Biomedical subjects

P Benson

Publications and source records attributed to P Benson.

At least 19 recordsLinked to original sources
PubMed2006

Orthodontic treatment for deep bite and retroclined upper front teeth in children.

BACKGROUND: Correction of the type of dental problem where the bite is deep and the upper front teeth are retroclined (Class II division 2 malocclusion) may be carried out using different types of orthodontic treatment. However, in severe cases, surgery to the jaws in combination with orthodontics may be required. In growing children, treatment may sometimes be carried out using special upper and lower dental braces (functional appliances) that can be removed from the mouth. In many cases this treatment does not involve taking out any permanent teeth. Often, however, further treatment is needed with fixed braces to get the best result. In other cases, treatment aims to move the upper first permanent molars backwards to provide space for the correction of the front teeth. This may be carried out by applying a force to the teeth and jaws from the back of the head using a head brace (headgear) and transmitting this force to a part of a fixed or removable dental brace. This treatment may or may not involve the removal of permanent teeth. In some cases, neither functional appliances nor headgear are required and treatment may be carried out without extraction of any permanent teeth. Instead of using a headgear, in certain cases, the back teeth are held back in other ways such as with an arch across or in contact with the front of the roof of the mouth which links two bands glued to the back teeth. Often in these cases, two permanent teeth are taken out from the middle of the upper arch (one on each side) to provide room to correct the upper front teeth. It is important for orthodontists to find out whether orthodontic treatment only, carried out without the removal of permanent teeth, in children with a Class II division 2 malocclusion produces a result which is any different from no orthodontic treatment or orthodontic treatment only involving extraction of permanent teeth. OBJECTIVES: To establish whether orthodontic treatment, carried out without the removal of permanent teeth, in children with a Class II division 2 malocclusion, produces a result which is any different from no orthodontic treatment or orthodontic treatment involving removal of permanent teeth. SEARCH STRATEGY: The Cochrane Oral Health Group's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and EMBASE were searched. The handsearching of the main international orthodontic journals was updated to April 2006. There were no restrictions with regard to publication status or language of publication. International researchers, likely to be involved in Class II division 2 clinical trials, were contacted to identify any unpublished or ongoing trials. SELECTION CRITERIA: Trials were selected if they met the following criteria: randomised controlled trials (RCTs) and controlled clinical trials (CCTs) of orthodontic treatments to correct deep bite and retroclined upper front teeth in children. DATA COLLECTION AND ANALYSIS: Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were to be conducted in duplicate and independently by two review authors. Results were to be expressed as random-effects models using mean differences for continuous outcomes and risk ratios for dichotomous outcomes with 95% confidence intervals. Heterogeneity was to be investigated including both clinical and methodological factors. MAIN RESULTS: No RCTs or CCTs were identified that assessed the treatment of Class II division 2 malocclusion in children. AUTHORS' CONCLUSIONS: It is not possible to provide any evidence-based guidance to recommend or discourage any type of orthodontic treatment to correct Class II division 2 malocclusion in children.

Child↗
PubMed2001

Measles-mumps-rubella and other measles-containing vaccines do not increase the risk for inflammatory bowel disease: a case-control study from the Vaccine Safety Datalink project.

CONTEXT: A link between measles virus-containing vaccines and inflammatory bowel disease (IBD) has been suggested by recent studies. OBJECTIVE: To address whether receipt or timing of measles-containing vaccine (MCV) increases risk for IBD. DESIGN: A case-control study. SETTING: Four large health maintenance organizations (HMOs) that are part of the Centers for Disease Control and Prevention's Vaccine Safety Datalink project. PATIENTS OR OTHER PARTICIPANTS: A total of 155 persons with codes from International Classification of Diseases, Ninth Revision specific for IBD, born between 1958 and 1989 and enrolled from birth to the onset of disease, were identified. Up to 5 controls were matched by sex, HMO, and birth year. INTERVENTION: None. MAIN OUTCOME MEASURES: Risk for IBD, Crohn's disease, and ulcerative colitis. RESULTS: Past vaccination was not associated with an increased risk for Crohn's disease (odds ratio [OR] for measles-mumps-rubella vaccine [MMR], 0.4; 95% confidence interval [CI], 0.08-2.0), ulcerative colitis (OR, 0.8; 95% CI, 0.18-3.56), or IBD (OR, 0.59; 95% CI, 0.21-1.68). Risk for IBD was not increased among children vaccinated who were younger than 12 months (OR for MMR, 0.61; 95% CI, 0.15-2.45) or aged 12 to 18 months (OR, 0.86; 95% CI, 0.28-2.59) relative to unvaccinated children. Children vaccinated with MMR who were older than 18 months were at significantly decreased risk for IBD (OR, 0.16; 95% CI, 0.04-0.68). Neither past vaccination nor age at vaccination with other MCV was associated with increased risk for Crohn's disease, ulcerative colitis, or IBD. Risk for Crohn's disease, ulcerative colitis, or IBD was not elevated in the time immediately following vaccination with either vaccine. CONCLUSIONS: Vaccination with MMR or other MCV, or the timing of vaccination early in life, did not increase the risk for IBD.

Adolescent↗
PubMed2000

Loss of ATM function enhances recombinant adeno-associated virus transduction and integration through pathways similar to UV irradiation.

Ataxia telangiectasia is caused by a genetic defect in the ATM gene that results in altered cellular sensitivity to DNA-damaging agents such as gamma-irradiation. ATM deficiency is associated with an increased incidence of neurological disorders, immune deficiency, and cancer. In this report we demonstrate that recombinant adeno-associated virus (rAAV) gene transfer in ATM-deficient fibroblasts is significantly enhanced over normal fibroblast cell lines. This enhancement of rAAV transduction in AT cells is correlated with an increased abundance of circular form rAAV genomes, as well as a higher number of integrated head-to-tail concatamer proviral genomes. Studies evaluating AAV trafficking using Cy3-labeled virus suggest that a nuclear mechanism is responsible for increased rAAV transduction in AT cells, because binding, endocytosis, and nuclear trafficking of virus are unaffected by the AT phenotype. Additionally, the profile of rAAV transduction after UV irradiation is significantly blunted in AT cells, suggesting that the level of DNA repair enzymes normally associated with UV augmentation of viral transduction may already be maximally elevated. These results further expand our understanding of genes involved in rAAV transduction.

Ataxia Telangiectasia↗
PubMed2000

Safety of oral versus intravenous hydration during induction therapy with intravenous foscarnet in AIDS patients with cytomegalovirus infections.

We undertook a study to compare the safety of intravenous (i.v.) versus oral hydration to prevent nephrotoxicity associated with the use of foscarnet for induction therapy of cytomegalovirus (CMV) infection in HIV-infected persons. Patients, given foscarnet at a dose of 90 mg/kg every 12 h, were randomized to receive either i.v. or oral hydration. Thirty-seven patients were given i.v. hydration and 44 were given oral hydration. Median duration of therapy for both groups was 17 days. There was no difference between the 2 groups in either serious adverse events or rise of creatinine to > or = 2.0 mg/dl. However, serum creatinine, while generally remained within normal limits, increased more in patients who received oral hydration after 10 days of therapy (significant only by slope analysis, P < 0.05). Although i.v. hydration provided better protection against nephrotoxicity, oral hydration was relatively safe and convenient provided that creatinine clearance (CrCl) is monitored closely.

AIDS-Related Opportunistic Infections↗
PubMed1999

Safety of revaccination with pneumococcal polysaccharide vaccine.

CONTEXT: Revaccination of healthy adults with pneumococcal polysaccharide vaccine (PPV) within several years of first vaccination has been associated with a higher than expected frequency and severity of local injection site reactions. The risk of adverse events associated with revaccination of elderly and chronically ill persons 5 or more years after first vaccination, as is currently recommended, has not been well defined. OBJECTIVE: To determine whether revaccination with PPV at least 5 years after first vaccination is associated with more frequent or more serious adverse events than those following first vaccination. DESIGN: Comparative intervention study conducted between April 1996 and August 1997. PARTICIPANTS: Persons aged 50 to 74 years either who had never been vaccinated with PPV (n = 901) or who had been vaccinated once at least 5 years prior to enrollment (n = 513). INTERVENTION: PPV vaccination. MAIN OUTCOME MEASURES: Postvaccination local injection site reactions and prevaccination concentrations of type-specific antibodies. RESULTS: Those who were revaccinated were more likely than those who received their first vaccinations to report a local injection site reaction of at least 10.2 cm (4 in) in diameter within 2 days of vaccination: 11% (55/513) vs 3% (29/901) (relative risk [RR], 3.3; 95% confidence interval [CI], 2.1-5.1). These reactions resolved by a median of 3 days following vaccination. The highest rate was among revaccinated patients who were immunocompetent and did not have chronic illness: 15% (33/228) compared with 3% (10/337) among comparable patients receiving their first vaccinations (RR, 4.9; 95% CI, 2.4-9.7). The risk of these local reactions was significantly correlated with prevaccination geometric mean antibody concentrations. CONCLUSIONS: Physicians and patients should be aware that self-limited local injection site reactions occur more frequently following revaccination compared with first vaccination; however, this risk does not represent a contraindication to revaccination with PPV for recommended groups.

Aged↗
PubMed1998

Alterations in acid-base balance and serum electrolyte concentrations in cattle: 632 cases (1984-1994).

OBJECTIVE: To determine typical alterations in acid-base balance and serum electrolyte concentrations in cattle grouped on the basis of age, breed type, hydration status, clinical signs, and underlying disease. DESIGN: Retrospective study. ANIMALS: 632 cattle. PROCEDURE: Information on blood pH, PVO2, PVCO2, HCO3-concentration, and base excess (BE) as well as serum or plasma sodium, potassium, chloride, and total carbon dioxide concentrations was obtained. Values for calves (ie, cattle < 1 month old) were compared with values for cattle > or = 1 month old. Within each age-group, values were compared for cattle grouped on the basis of breed type, previous treatment, and hydration status. Proportions of cattle with various disorders for which values were within, greater than, or less than reference ranges were determined. RESULTS: BE, pH, and HCO3- concentration were significantly higher and PVCO2 and sodium, potassium, and chloride concentrations were significantly lower among cattle > or = 1 month old than calves. Base excess and HCO3- concentration were significantly lower among dairy than beef calves. Sodium and potassium concentrations were significantly lower among dairy than beef cattle > or = 1 month old. A higher proportion of cattle that did not survive had a high anion gap than cattle that did survive. Sodium, potassium, and chloride concentrations were significantly lower among dehydrated cattle than cattle that were not dehydrated. CLINICAL IMPLICATIONS: Because certain alterations were consistently found in some groups of cattle, it may be possible to make reasonable predictions of alterations in acid-base balance and serum electrolyte concentrations when laboratory evaluations are not available.

Acid-Base Equilibrium↗
PubMed1998

Epidemiology of congenital cytomegalovirus infection: maternal risk factors and molecular analysis of cytomegalovirus strains.

To determine factors that influence the occurrence of congenital cytomegalovirus (CMV) infection, the authors surveyed prospectively 8,254 infants born in eastern Iowa between October 1989 and June 1994. The authors conducted a case-control study to identify maternal risk factors, matching each CMV-infected infant with three uninfected infants according to hospital and date of birth. CMV strains were compared by using the polymerase chain reaction (PCR) to identify common sources of infection. Of the 7,229 infants cultured successfully for CMV, 35 (0.48%) were congenitally infected. Mothers of CMV-infected infants were more likely to be single (odds ratio (OR) = 3.05, p = 0.016), to work in sales (OR = 4.93, p = 0.008), or to be students (OR = 5.01, p = 0.017). Conversely, women who worked in health-care professions were less likely to have a congenitally infected infant (OR = 0.14, p = 0.049). PCR analysis indicated 27 distinct strains of CMV, but two groups of infants (two infants per group) excreted strains with indistinguishable molecular patterns. One of these pairs of infants had older siblings who attended the same child-care center during their mothers' pregnancies. The authors concluded that demographic and occupational factors influenced the risk of giving birth to an infant with congenital CMV infection. Many distinct CMV strains were identified, suggesting that major point source outbreaks had not occurred. Nonetheless, point source acquisition of CMV from child-care environments did account for some cases of congenital CMV infection in eastern Iowa.

Adult↗
PubMed1996

Parent and sibling influences on adolescent alcohol use and misuse: evidence from a U.S. adoption cohort.

OBJECTIVE: Although adolescent alcohol use has been consistently associated with parental drinking behavior, sibling drinking behavior and family functioning, the extent to which these associations owe to genetic or shared environmental influences has not been previously investigated. Using an adoption study design, we sought to determine whether the familial correlates of adolescent alcohol involvement were due to common genetic or common environmental effects. METHOD: The sample consisted of 653 adopted families ascertained through adoption agencies in four U.S. states. Each family consisted of a target adopted adolescent, an adoptive mother and an adoptive father. In addition, 68 birth adolescents (i.e., biological offspring of the adoptive parents) and 187 second adopted adolescents from these families participated in the study. All participants completed a mail survey that included assessment of drinking behavior and family functioning. RESULTS: The relationship between parental problem drinking and adolescent alcohol involvement was moderate and significant among birth offspring (corrected multiple correlation, Rc = .30), but small and non-significant among adoptive offspring (Rc = .00). The relationship between adolescent alcohol involvement and family functioning was substantial for birth offspring (Rc = .39), but only modest for adoptive offspring (Rc = .16). The nonbiological sibling correlation for involvement with alcohol was significant (r = .24) and moderated by sibling pair demographic similarity, such that same-sex, similar-age siblings were substantially more similar (r = .45) than opposite-sex, dissimilar-aged siblings (r = .01). CONCLUSIONS: These findings suggest that adolescent alcohol use is affected minimally by the environmental consequences of parent problem drinking and family functioning, but substantially by sibling environmental effects.

Adolescent↗
PubMed1995

Chronic sulfasalazine therapy in the treatment of delayed pressure urticaria and angioedema.

BACKGROUND: Delayed pressure urticaria/angioedema can be profoundly disabling with painful and prolonged swelling of feet and hands as well as systemic symptoms of malaise and flu-like illness. Occupations requiring prolonged standing and forceful use of hands may be seriously compromised by this condition. The severe forms of the disease are usually unresponsive to antihistamines and nonsteroidal anti-inflammatory drugs, and patients frequently require corticosteroids for control of symptoms. OBJECTIVE: It was the purpose of this report to evaluate the clinical utility of sulfasalazine for two patients with refractory delayed pressure urticaria. METHODS: Sulfasalazine, starting at 500 mg/day (with weekly incremental dosing to a total of 4 g), was administered to two patients with disabling pressure urticaria and angioedema (symptomatic daily with normal activities) who had failed all other reported therapeutic options except corticosteroids. RESULTS: Patient A required daily prednisone in excess of 30 mg (for more than 6 months) to control his painful angioedema sufficiently in order to continue working as a colorectal surgeon. Patient B also experienced daily symptoms for more than 1 year. Both patients tolerated sulfasalazine to a dose of 4 g/day without adverse reactions and achieved complete resolution of symptoms. Patient A continued to be well controlled 1 year after starting but must maintain a dose of 2 g or greater per day. Patient B reported excellent control 6 months after starting but was subsequently lost to follow-up. CONCLUSION: Sulfasalazine, in doses used for inflammatory bowel disease, appears to be an effective alternative therapy for delayed pressure urticaria and angioedema in patients poorly controlled by traditional treatment and may act as a corticosteroid-sparing agent.

Adult↗
PubMed1994

Allelic loss in locally metastatic, multisampled prostate cancer.

In order to determine whether retention or loss of potential tumor suppressor loci that map to 8p, 10q, or 16q reflect genetic relationships among prostatic intraepithelial neoplasias (PINs), multicentric primary prostatic cancers, and regional lymph node metastases or are associated with the metastatic phenotype, we analyzed 19 cases of locally metastatic prostate carcinoma (stage D1) utilizing polymerase chain reaction techniques. In each case, tissue samples from metastatic tumor, the (dominant) primary tumor, and nonneoplastic prostatic tissue were examined. In selected cases, allelic loss in additional tumor foci, separate from the dominant tumor nodule, and areas of PIN were examined. Allelic loss of sequences on 8p, 10q, and 16q were observed in 20-29% of PINs, 18-42% of primary tumors, and 8-25% of metastatic tumors. Discrepancies in sequence dosage between histological components were most pronounced for 8p sequences, especially between the dominant tumor nodule and metastatic deposits in cases in which > or = 3 separate tumor foci/gland were identified. These results suggest that putative premalignant lesions, moderately or poorly differentiated, geographically separate primary tumor foci, and metastases within morphologically "complex" prostates (those with > or = 3 foci/gland) are likely to be more discordant for sequence dosage at 8p than those within "simpler" glands (< 3 foci/gland). Also, our results suggest that lymph node metastases may be genetically related to either the dominant or additional primary tumor foci in more complex prostates and that accumulation of genetic aberration may differ in primary and metastatic lesions.

Alleles↗
PubMed1994

Clinical implementation of a rapid, automated assay for assessing fetal lung maturity.

We retrospectively determined cutoff levels and implemented the use of the TDxFLx assay in assessing the likelihood or absence of respiratory distress syndrome or fetal lung maturity (FLM) in a high-risk obstetric setting when compared to the lecithin/sphingomyelin (L/S) ratio and disaturated lecithin (DSL) measurements. Using a mature TDxFLx cutoff value of > or = 50 mg/g and an immature cutoff value of < 20 mg/g, 88% of L/S ratio and DSL measurements could be eliminated without compromise to the patient. The > or = 50 mg/g TDxFLx cutoff value resulted in a sensitivity of 100% and specificity of 88%. We also recommend the use of the TDxFLx assay as a screening test in diabetic pregnancies. More timely patient care occurred when the rapid TDxFLx assay was implemented by the laboratory and used by clinicians.

Albumins↗
PubMed1992

The beta globin gene cluster of the prosimian primate Galago crassicaudatus: nucleotide sequence determination of the 41-kb cluster and comparative sequence analyses.

The nucleotide sequence of the beta globin gene cluster of the prosimian Galago crassicaudatus has been determined. A total sequence spanning 41,101 bp contains and links together previously published sequences of the five galago beta-like globin genes (5'-epsilon-gamma-psi eta-delta-beta-3'). A computer-aided search for middle interspersed repetitive sequences identified 10 LINE (L1) elements, including a 5' truncated repeat that is orthologous to the full-length L1 element found in the human epsilon-gamma intergenic region. SINE elements that were identified included one Alu type I repeat, four Alu type II repeats, and two methionine tRNA-derived Monomer (type III) elements. Alu type II and Monomer sequences are unique to the galago genome. Structural analyses of the cluster sequence reveals that it is relatively A+T rich (about 62%) and regions with high G+C content are associated primarily with globin coding regions. Comparative analyses with the beta globin cluster sequences of human, rabbit, and mouse reveal extensive sequence homologies in their genic regions, but only human, galago, and rabbit sequences share extensive intergenic sequence homologies. Divergence analyses of aligned intergenic and flanking sequences from orthologous human, galago, and rabbit sequences show a gradation in the rate of nucleotide sequence evolution along the cluster where sequences 5' of the epsilon globin gene region show the least sequence divergence and sequences just 5' of the beta globin gene region show the greatest sequence divergence.

Amino Acid Sequence↗
PubMed1992

A bullous skin disease patient with autoantibodies against separate epitopes in 1 mol/L sodium chloride split skin.

BACKGROUND: We describe a patient with a subepidermal bullous skin disease associated with autoantibodies recognizing separate epitopes in 1 mol/L sodium chloride (NaCl) split skin. OBSERVATIONS: Direct immunofluorescence microscopy showed deposits of immunoglobulins and C3 in a continuous pattern in the patient's epidermal basement membrane zone. Direct immunoelectron microscopy demonstrated thick deposits of IgG overlying the lamina lucida and the lamina densa in a unique pattern. The patient had circulating IgG anti-basement membrane zone antibodies that bound both sides of 1 mol/L NaCl split skin, exhibited at least a fourfold-higher titer against the dermal side of this test substrate, and bound basal keratinocyte hemidesmosomes as well as focal sites along the superior portion of the lamina densa on indirect immunoelectron microscopy. Affinity purification of anti-basement membrane zone antibodies against epidermal or dermal strips of 1 mol/L NaCl split skin yielded IgG that only bound the side of split skin from which it was eluted. The patient's serum contained IgG that immunoprecipitated and immunoblotted the 230- and 170-kd bullous pemphigoid antigens. Affinity purification of patient antibody against bullous pemphigoid antigen immobilized on nitrocellulose paper yielded IgG that bound only the epidermal side of 1 mol/L NaCl split skin. The patient showed no evidence of reactivity against type VII collagen by direct immunoelectron microscopy, indirect immunoelectron microscopy, or immunoblot. CONCLUSIONS: This patient's bullous skin disease is associated with IgG anti-basement membrane zone antibodies with two specificities: one recognizing the bullous pemphigoid antigen in the epidermal side of 1 mol/L NaCl split skin, and another binding a distinct, yet presently unidentified, epitope in the superior aspect of the lamina densa.

Aged↗