Cervical length assessment in twin pregnancies using transvaginal ultrasound.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
D Campbell
Publications and source records attributed to D Campbell.
Estradiol/progesterone substitution in the luteal phase improves pregnancy rates in stimulated cycles--but only in younger women.
Innumerable studies have attempted to demonstrate that hormonal support of the luteal phase during ovulation induction cycles improves pregnancy rates. None has, however, so far been able to confirm the validity of such treatment conclusively, possibly because most studies only utilized progesterone substitution. Since luteal phase endometrium also requires estradiol support, this study attempted to investigate whether hormone substitution with progesterone and estradiol would be more successful in improving pregnancy rates. Amongst approximately 7500 consecutive ovulation induction cycles were identified prospectively which were characterized by a precipitous drop of luteal phase serum estradiol levels by more than 50% over a 48 hour period within 10 days from hCG administration. Those cycles were prospectively randomized to oral micronized estradiol substitution (Group I) or not (Group II), while both groups received routine progesterone substitution of the luteal phase. Cycles were then evaluated in regards to the occurrence of chemical, ectopic and clinical pregnancies. One hundred sixty-three Group I cycles resulted in 34 pregnancies (20.9%), which compared favorably to 21 pregnancies in 167 Group II patients (12.6%) (x2[1] = 4.06; p < 0.04). The advantage for Group I cycles (29/95 pregnancies, 31%) vs. Group II cycles (16/105, 15%) became even more pronounced when only women up to age 35 years were evaluated. Estradiol substitution maintained a significant advantage until age 38 (x2 [1] = 6.87; p < 0.009). While gravidity did not affect pregnancy success, estradiol substitution in Group I benefited nulliparous (23% pregnancy rate) over multiparous women (12% pregnancy rate) (x2 [2] = 6.86; p< 0.03). This association was, however, age-dependent. A combined estradiol and progesterone substitution of the luteal phase of ovulation induction cycles increases the overall pregnancy rate. Since estradiol substitution was initiated in this study only once a precipitous drop in serum estradiol levels had already taken place, an even larger improvement in pregnancy rates could conceivably be possible if earlier estradiol substitution of the luteal phase is initiated. A further expansion of investigations of similar protocols for routine ovulation induction and in vitro fertilization (IVF) cycles may be indicated, especially in women below age 38 years and in nulliparous females.
Administration, Oral↗
Reduction of high-risk behaviors among incarcerated youths: a challenge in prevention.
The adolescent population in America is at increasing risk for acquiring the human immunodeficiency virus (HIV) that causes AIDS (CDC, 1998; 1996; 1994; 1993). Although the total number of reported AIDS cases among adolescents 12 to 19 years of age is, thus far, fairly small, the identified caseload in this age group has increased by over 40% during one year alone. In fact, one-fifth of all reported AIDS cases occur among persons 20 to 29 years of age. Many of these young adults contracted HIV infections as teenagers (CDC, 1996). But the trend is changing. In fact, among younger youths, especially those of African heritage, the infection rates are rapidly increasing (CDC, 1999; CDC, 1998). These increases will require focused attention by all health professionals, and public policy officials (Lai, Tsai, Hardy, 1997; Porter, Oakley, Guthrie & Killion, 1999). The purpose of this current study was to describe risk-related behaviors of incarcerated youths that are significant factors when planning community-based programs for HIV/AIDS prevention. Several research questions were generated in this regard and tested. Several significant findings emerged from the data that indicate that African-American youths incarcerated are at greater risk for development of HIV/AIDS than their other ethnic counterparts.
Adolescent↗
New alpha-substituted succinate-based hydroxamic acids as TNFalpha convertase inhibitors.
Tumor necrosis factor alpha convertase (TACE), the enzyme responsible for the processing of pro-TNFalpha to TNFalpha, has been reported to be a metalloproteinase closely related to matrix metalloproteinases (MMPs). Current inhibitors of TACE such as succinate-based hydroxamic acids exemplified by Marimastat (TACE IC(50): 3.8 nM; blood IC(50): 7 microM) and BB1101 (TACE IC(50): 0.2 nM; blood IC(50): 2.3 microM) suffer from modest potency in blood and poor in vivo properties. The introduction of new bulky alpha-substituents into these succinate-based hydroxamic acids was studied. Substituents such as thioethers, sulfonamides, and ethers showed improved potency against TACE when compared with Marimastat. Although this improvement did not translate into better blood potency for thioether or ether substituents, the sulfonamide series exhibited improved potency both against TACE and in blood when compared with Marimastat. Optimization of this sulfonamide series has culminated in the identification of heterocyclic bicyclic sulfonamides such as 3t (TACE IC(50): 0.57 nM; blood IC(50): 0.28 microM).
ADAM Proteins↗
Comparison of four components of sensory gating in schizophrenia and normal subjects: a preliminary report.
Dysfunction of sensory gating has been implicated in the pathophysiology of schizophrenia. The goal of this study was to provide evidence that sensory gating dysfunction in schizophrenia patients is a compounded problem with difficulty in filtering out irrelevant input and filtering in relevant input at both an early-preattentive stage and a later, early-attentive stage of information processing. Four components of sensory gating were examined in 12 medicated, stable schizophrenia patients and 12 age- and sex-matched normal control subjects. Evoked potential paradigms designed to examine the effects of stimulus repetition and stimulus change were utilized. Attenuation of the amplitude of the P50 and the N100 evoked potentials with stimulus repetition was significantly decreased in schizophrenia patients as compared to normal control subjects. The presentation of deviant stimuli caused the degree of attenuation to decrease in normal subjects. This effect was much decreased (and at times reversed) in schizophrenia subjects. These data suggest that schizophrenia patients have difficulty inhibiting incoming, irrelevant stimuli and responding to incoming, significant input as measured by preattentive EPs (P50). The data also suggest that similar abnormalities can be demonstrated at a slightly later phase of information processing (i.e. early-attentive phase) using the N100 EP.
Adult↗
Role of cytomegalovirus in the T cell changes seen in elderly individuals.
The effect of prior cytomegalovirus (CMV) infection on the immune system was evaluated in young and elderly volunteers. Prevalence of IgG antibodies to CMV was higher in the elderly volunteers. In both age groups, there was a strong association with CMV seropositivity and increased number of CD28- CD4 or CD8 T cells, as well as with increased numbers of T cells expressing CD56 or DR. Although these changes have previously been reported to be age-related, they were independent of age when CMV serological status was taken into account. In contrast, both age group and CMV status were important determinants of the total number of T cells, the number of CD8 T cells, and the number of CD8 T cells expressing CD45RA or CD28. These findings indicate that prior infection with CMV, as reflected by CMV serological status, has important effects on T cell subsets and surface markers and must be considered whenever evaluating age-related changes in immunological parameters.
Adult↗
A susceptibility region for myasthenia gravis extending into the HLA-class I sector telomeric to HLA-C.
We have analyzed a series of HLA region markers in 207 UK Caucasoids with early-onset myasthenia gravis (EOMG, onset before age 40), where there is a strong female bias. The well known associations with HLA-DR3 and -B8 have now proved to be significantly stronger in the 165 females than in the 42 males. In patients (of either sex) lacking -DR3, there was also a significant increase in HLA-DR2. Although the muscle weakness in EOMG is clearly mediated by autoantibodies, the associations are consistently stronger with HLA-B8 (in class I) than with HLADR3 (in class II), as confirmed here. We therefore typed 87-137 cases for polymorphisms at four loci in the intervening class III region, and also at three in the adjacent stretch of class I. At each locus, one allele tended to co-occur with HLA-B8 and showed strong and highly significant associations in the patients. There appeared to be a region of maximal susceptibility extending from HSP70 (in class III) past HLA-B and HLA-C at least 600 kb telomerically into the class I region, which is now being mapped in detail. Any candidate genes here that act shortly after puberty may allow more precise localization of susceptibility.
Adult↗
Double-blind comparison of lansoprazole 15 mg, lansoprazole 30 mg and placebo as maintenance therapy in patients with healed duodenal ulcers resistant to H2-receptor antagonists.
BACKGROUND: Maintenance antisecretory therapy is often used to prevent duodenal ulcer recurrence and control symptoms. This study compared the efficacy and safety of lansoprazole 15 mg and 30 mg daily with placebo in preventing ulcer recurrence in patients with a recent history of duodenal ulcer disease. METHODS: Fifty-six patients were treated with either lansoprazole 15 mg, 30 mg or placebo o.m. RESULTS: Within 1 month of study initiation, 27% (four out of 15) of placebo-treated patients experienced ulcer recurrence as compared to 13% (two out of 15) and 6% (one out of 18) of lansoprazole 15 mg and 30 mg treated patients, respectively. Median time to first ulcer recurrence was > 12 months in lansoprazole patients. At Month 12, significantly (P < 0.001) more lansoprazole 15 mg patients (70%) and lansoprazole 30 mg patients (85%) remained healed. Eighty-two per cent of lansoprazole 15 mg and 76% of lansoprazole 30 mg patients remained asymptomatic during the entire study period. All placebo patients became symptomatic, experienced ulcer recurrence, or withdrew from the study by month six. The incidence of adverse events was comparable among the three treatment groups. CONCLUSIONS: Lansoprazole safely and effectively reduces duodenal ulcer recurrence and ulcer-related symptoms.
2-Pyridinylmethylsulfinylbenzimidazoles↗
Serum from Entamoeba histolytica-infected gerbils selectively suppresses T cell proliferation by inhibiting interleukin-2 production.
Suppression of T and B cell responses during invasive amebiasis may be serum mediated. The mechanism of serum-mediated suppression of spleen cell lymphoproliferation from gerbils with amebic liver abscess was examined. Compared with uninfected gerbil serum (10%), serum samples collected at days 10, 30, and 60, but not at day 20 after infection, augmented both concanavalin A (Con A; T cell mitogen)- and lipopolysaccharide (LPS; B cell mitogen)-induced proliferation of homologous spleen cells. Only day 20 serum (>5%) inhibited Con A- but not LPS-induced proliferation of spleen cells from uninfected gerbils. The suppressive mechanism was independent of nitric oxide and prostaglandin but involved reduced interleukin (IL)-2 production. Addition of exogenous IL-2 reversed the suppressive effect of day 20 serum on Con A-stimulated proliferation. These results identify a mechanism whereby serum may contribute to transient suppression of T cell responses during Entamoeba histolytica infections.
Animals↗
Population pharmacokinetics of aminoglycoside antibiotics in patients with cystic fibrosis.
The population pharmacokinetics of gentamicin and tobramycin were investigated in a group of 51 young adults with cystic fibrosis. Their ages ranged from 14-35 years, weights from 38-82 kg, and 27 of the patients were female. None of the patients had renal impairment, but 3 patients were treated in the intensive therapy unit (ITU) during one of their courses of therapy. Data comprised 219 courses of therapy and 544 concentrations (mean: 11 per patient). Concentration-time data were analyzed using a nonlinear mixed-effects model package (NONMEM) and were best described by a one-compartment model. Factors identified as potentially influencing aminoglycoside pharmacokinetics were added in a stepwise fashion and the best model found that drug clearance and volume of distribution were related to body surface area and admission to ITU. The mean population estimates were a clearance of 2.89 L/hr/m2 and a volume of distribution of 9.21 L/m2 with a 60% increase in patients who were admitted to ITU. Interpatient variability in clearance and volume were 14% and 8%, respectively. The results suggested that a dose of 120 mg/m2 should achieve an average 1 hour postdose peak of 10 mg/L and trough of <1 mg/L and that higher doses might be required in ITU patients.
Adolescent↗
Estimation of fetal weight in twins: a new mathematical model.
OBJECTIVES: Evaluation of new mathematical formula (Femur 4) derived from a twin population to estimate fetal weight in twins using ultrasound. Comparison of Femur 4 is with conventional mathematical models. DESIGN: Retrospective analysis of ultrasonic measurements of 297 twin babies from 24 to 40 weeks of gestation who were born within 10 days of ultrasound examination. SETTING: Aberdeen Maternity Hospital. METHODS: With ultrasonic measurements obtained from twin babies, estimated fetal weight was calculated using the mathematical models of Campbell, Shepard and Hadlock. The calculations were repeated for the model of Femur 4. All models were compared against Femur 4. RESULTS: The coefficient of determination of the linear regression between the actual and predicted weight was highest for Femur 4 (0.852). Femur 4 had the highest proportion of babies with estimated weights within 10% of actual birthweight (71.4%). In babies who weighed between 2000 and 3000 g, Femur 4 had the least systematic and random error of -1.69 and 8.96, respectively. For babies below the 10th centile for weight, Femur 4 had comparable positive and negative predictive values of 76.0% and 92.3%, respectively. Femur 4 was equally poor at predicting growth discordancy with positive and negative predictive values of 70.0% and 86.5% only. CONCLUSION: Femur 4 requires measurements of femur length and abdominal circumference only, hence avoiding the need to obtain difficult head measurements which is a common problem in twins. It is a good model for estimation of fetal weight in twins. However, prediction of growth discordancy remains problematic.
Body Weight↗
A fuzzy logic-controlled classifier for use in implantable cardioverter defibrillators.
PURPOSE: Implantable cardioverters defibrillators (ICDs) are increasingly used in the management of life-threatening arrhythmias. Correct recognition of a treatable arrhythmia is crucial to this application. However, the computational power of microprocessors currently used in ICDs limits the range of traditional algorithms available for this application. METHODS: Classification based on fuzzy inference systems (FIS) were trained to recognize different cardiac rhythms (AF, VF, SVT, VT) from the Ann Arbor Electrogram Library. The FIS used were designed using adaptive-network-based fuzzy inference methods to optimize the classification procedure. Only computational techniques suitable for ICD design were used. RESULTS: After pretraining with the ANFIS correct rhythm classification was observed for the rhythms studied. CONCLUSION: In this preliminary study, successful rhythm classification was demonstrated using fuzzy logic techniques. In view of the computational efficiency this may have application in ICD design.
Arrhythmias, Cardiac↗
Deficient antibody-dependent cellular cytotoxicity against human immunodeficiency virus (HIV)-expressing target cells in perinatal HIV infection.
Peripheral blood mononuclear cells (PBMC) of human immunodeficiency virus (HIV)-infected children, age-matched HIV-seronegative controls, and HIV-infected asymptomatic and symptomatic adults were compared for their ability to mediate antibody-dependent cellular cytotoxicity (ADCC) and natural killer (NK) cell-mediated cytotoxicity against target cells expressing HIV or herpes simplex virus (HSV) antigens. Target cells consisted of CD4 lymphocytes purified from PBMC of HIV-seronegative adults and incubated with the IIIB strain of HIV, HUT78 cells chronically infected with IIIB, and HSV-infected human fibroblasts. PBMC of asymptomatic HIV-infected adults were generally able to lyse CD4 cells expressing HIV antigens. Direct correlation was found between the magnitude of lysis and absolute CD4 cell counts in these individuals. In contrast to these results, PBMC from HIV-infected children were generally unable to lyse IIIB-expressing CD4 cells, regardless of the children's clinical status, age, or absolute CD4 cell counts. Cells from HIV-seronegative adults and children did not directly lyse these target cells either but, in contrast to cells of HIV-seropositive children, were able to mediate cell lysis when serum from an HIV-seropositive adult was added. However, effector cells from these HIV-infected children were able to mediate both ADCC against HSV-infected fibroblasts and NK cell-mediated cytotoxicity against IIIB-infected HUT78 cells. Reduced ability of PBMC from vertically HIV-infected children to mediate ADCC against HIV antigen-expressing CD4 cells may contribute to rapid progression to AIDS.
Adult↗
A survey of infections in United Kingdom laboratories, 1994-1995.
AIMS: To identify the number and type of infections occurring in United Kingdom clinical laboratories during 1994 and 1995, following similar surveys covering 1970 to 1989. METHODS: A retrospective questionnaire survey was undertaken of 397 responding UK clinical laboratories covering 1994 and 1995. A follow up telephone survey was undertaken with each of the laboratories from which a questionnaire had been received indicating a possible or probable laboratory acquired infection during 1994 or 1995. RESULTS: Questionnaires were sent to 659 laboratories or organisations which were thought to have laboratories, of which 557 responded (response rate of 84.5%). Of these, only 397 were from organisations with laboratories. Over 55,000 person-years of occupational exposure were covered, and only nine cases identified, giving an infection incidence rate overall of 16.2/100,000 person-years, compared with 82.7 infections/100,000 person-years found in a similar survey covering 1988 and 1989, reported previously. Infections were commonest in females, in relatively young staff, in microbiology laboratory workers, and in scientific/technical employees. Gastrointestinal infections predominated, particularly shigellosis, but few specific aetiological factors relating to working practices were identified. No hepatitis B cases were reported. CONCLUSIONS: The small number of cases identified indicates high standards of infection control, though there is still room for improvement. Periodic studies of this kind are not adequate for comprehensive monitoring of the incidence of laboratory acquired infections. That will require the introduction of a routine, active surveillance programme or prospective survey which has the support and commitment of the laboratories themselves.
Adult↗
Factors relating to readmission of term and near-term neonates in the first two weeks of life. Early Discharge Survey Group of the Health Professional Advisory Board of the Greater New York Chapter of the March of Dimes.
AIMS: A multisite study of term and near term infants readmitted in the first two weeks of life to 9 New York City area hospitals in 1995 was conducted to evaluate factors related to readmission, including length of newborn stay. RESULTS: Of the 30,884 infants born at the 9 study hospitals 391 newborns were readmitted. The major admission diagnoses were infection, 40.7%, hyperbilirubinemia, 39.1%, and feeding and/or gastrointestinal problems, 10.5%. In the first week, 65.1% of readmissions were for hyperbilirubinemia and 19.1% were for infection or suspected sepsis. In the second week, 67.8% of readmissions were for infection and 7.6% were for hyperbilirubinemia. Hyperbilirubinemia was the most frequent diagnosis for White and Asian infants, while infection was most frequent for African-American and Hispanic infants. Age at readmission was younger and the interval from discharge was shorter for infants with hyperbilirubinemia. Abnormalities which should have precluded early discharge included feeding difficulties, cyanotic congenital heart defects, hemolytic disease of the newborn, early jaundice or early high bilirubin levels. CONCLUSION: Attention to identification of infants at risk and programs such as lactation counseling and universal screening for bilirubin (with appropriate interpretation) prior to discharge could have reduced the necessity for readmission regardless of the newborn length of stay.
Adolescent↗
Populational heterogeneity of Brazilian Trypanosoma cruzi isolates revealed by the mini-exon and ribosomal spacers.
Explore the source record for details and available documents.
Animals↗
Tumors in wild adult raccoons from a suburban area.
Explore the source record for details and available documents.
Adenoma↗
Disconnect alarm failure.
Explore the source record for details and available documents.
Anesthesiology↗