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Biomedical subjects

J Dalrymple

Publications and source records attributed to J Dalrymple.

18 recordsLinked to original sources

Upper limits on a stochastic background of gravitational waves.

The Laser Interferometer Gravitational-Wave Observatory has performed a third science run with much improved sensitivities of all three interferometers. We present an analysis of approximately 200 hours of data acquired during this run, used to search for a stochastic background of gravitational radiation. We place upper bounds on the energy density stored as gravitational radiation for three different spectral power laws. For the flat spectrum, our limit of omega0 < 8.4 x 10(-4) in the 69-156 Hz band is approximately 10(5) times lower than the previous result in this frequency range.

Journal Article↗

Outcomes following unilateral uterine artery embolisation.

Uterine artery embolisation has been described as successful only when both arteries are embolised. However, results in patients with one congenitally absent or previously ligated artery are unknown. Women suffering from symptomatic uterine myomata were treated at a university teaching hospital, a community hospital and an outpatient surgery centre. Retrospective review of patient response to embolisation was assessed by chart review and questionnaire. Uterine and dominant fibroid size response was assessed by comparing pre- and post-embolisation ultrasound examinations. This study analysed three patient groups within the general population: those who underwent unilateral embolisation because of technical failure, those who ultimately underwent bilateral embolisation after initial technical failure and those who underwent unilateral embolisation because of an absent uterine artery. 12 patients underwent unilateral embolisation, 4 of whom underwent this procedure because of an absent uterine artery. Three of these four patients had a congenitally absent uterine artery arising from the internal iliac artery and all three experienced successful outcomes. The fourth patient had a previously ligated internal iliac artery and her symptoms worsened after the procedure. Eight patients had unilateral embolisation due to technical failure. Five of these patients underwent a subsequent procedure during which the contralateral uterine artery was embolised. Four of these five patients had successful outcomes and one was lost to follow-up. Another of the eight patients suffered an arterial injury leading to technical failure, and was lost to follow-up. Of the two remaining patients with unilateral technical failure, only one had a successful outcome. This study concluded that patients who undergo unilateral embolisation for technical reasons should be offered a second embolisation procedure shortly after the initial procedure. Patients with a congenitally absent uterine artery may respond with similar success to those who underwent bilateral embolisation. In contrast, the patient with a previously ligated internal iliac artery failed. The numbers in this study are too small for statistical analysis and subsequent studies should be performed to confirm these findings.

Angiography↗

Cross sectional study of reporting of epileptic seizures to general practitioners.

OBJECTIVE: Comparison of reporting of recent epileptic seizures by patients to a doctor and anonymously. DESIGN: Cross sectional study of patients with epilepsy by comparison of paired questionnaires. SETTING: Rural and urban general practices in Norfolk. PARTICIPANTS: 122 patients aged over 16 years and able to self complete a questionnaire who were recruited by 31 general practitioners when attending for review of their epilepsy. MAIN OUTCOME MEASURE: The difference in reported occurrence of seizure to general practitioners and in a linked anonymous questionnaire. RESULTS: 18 patients failed to report a seizure in the past year to their general practitioner (uncontrolled epilepsy). 40% (24/60) of people with epilepsy who anonymously reported a seizure in the past year held a driving licence, but only six revealed this to their general practitioner. The unemployment rate was 34%, substantially higher than the 9% in the general population. Measures of anxiety, depression, and stigmatization were higher in patients with uncontrolled epilepsy. CONCLUSIONS: A significant proportion of patients with epilepsy under-report their seizures. Recognition of underreporting is important if patients are to benefit from adequate and appropriate treatment. General practitioners' ability to treat epilepsy is hampered by their role in regulating the rights of epileptic patients to hold a driving licence or access certain occupations.

Adolescent↗

Clinical results from intracytoplasmic sperm injection at monash IVF.

The impact of a modification of the intracytoplasmic sperm injection (ICSI) technique on fertilization and pregnancy rates was examined in a retrospective analysis of 171 consecutive ICSI treatment cycles (156 patients). Patients were selected for ICSI on the basis of severe oligoasthenozoospermia (65 patients) or following conventional in vitro fertilization (IVF) with failed or poor fertilization (70 patients). Seven patients in which epididymal or testicular sperm was used, 10 patients with sperm antibodies and 4 patients with retrograde ejaculation or who required electro-ejaculation were also treated with ICSI. In the first 105 cycles (102 patients), single sperm, rendered immotile, were injected into the ooplasm of 979 metaphase II (M II) oocytes using an established technique (Method 1). In the following 66 cycles (513 M II oocytes injected), the ICSI procedure was modified by increased aspiration of the oolemma to ensure the intracytoplasmic deposition of sperm (Method 2). The patient groups did not differ between the two injection procedures. The normal (two pronuclear) fertilization rate increased significantly (P < 0.001) from 34.3% with Method 1 to 73.1% with Method 2, with no difference in the oocyte degeneration rate (4.3% v. 4.5% respectively). The incidence of failed fertilization was significantly (P < 0.01) reduced from 17.1% (18 cycles) to 1.6% (1 cycle) with the change in technique. As a consequence of the increased fertilization rates with Method 2, more embryos were available for assessment and transfer, and a pregnancy rate per oocyte retrieval of 21.2% was obtained for Method 2. Fertilization, embryo transfer and pregnancies were obtained in all patient groups treated with ICSI.(ABSTRACT TRUNCATED AT 250 WORDS)

Australia↗

Why do patients default from follow-up at a genitourinary clinic?: a multivariate analysis.

OBJECTIVE: Firstly to compare the proportion of patients defaulting from follow up at a genitourinary medicine clinic with those attending other hospital based clinics. Secondly to determine which factors are associated with non attendance at a city centre genitourinary medicine clinic. METHODOLOGY: The proportion of patients who defaulted at a genitourinary medicine clinic, a general medical clinic, a general surgical clinic and a dermatology clinic during March 1995 were compared. A multivariate logistic regression analysis was performed comparing attenders and non attenders at the genitourinary medicine clinic with respect to time of appointment, diagnosis, previous contacts with clinic staff, potential domestic commitments and patient demographics in a prospective case control study. RESULTS: The default rate at the genitourinary medicine clinic was 15% compared with 13%, 15% and 14% for medical, surgical and dermatology clinics respectively. Patients who defaulted from the genitourinary medicine clinic (167) were compared with 172 attenders and significant differences found for timing of appointments, area of residence, frequency of counselling by the health advisor and age of the patient. Other factors such as the diagnosis, whether a woman had children, sexual orientation, whether negative results had been given over the phone, source of referral, sex of patient, employment status and the weather were not found to be significantly associated with defaulting from an appointment. CONCLUSIONS: The time of the appointment and being seen by a health advisor were the only variables identified over which the clinic has control and therefore could potentially reduce non attendance rates.

Adult↗

Serum antibodies to structural proteins of Hantavirus arise at different times after infection.

An enzyme-linked immunosorbent assay (ELISA) was developed for the quantification of serum antibodies against group-specific epitopes of the glycoproteins (G1, G2) and nucleoprotein (NP) of the genus Hantavirus. This assay was used to study the kinetics of the development of serum antibodies after natural infection with Puumala-like virus in humans. To this end a panel of 34 serum samples collected from individuals at different times after natural infection was tested by the ELISA. The samples were also tested for specific IgM and IgG levels against Puumala-like virus, which provided confirmatory data about the presumed timing of infection. It was shown that serum antibodies against the G1 epitope were present in the acute and early convalescent period just before antibodies to the NP epitope could be demonstrated. In contrast, antibodies to two G2 epitopes were present not earlier than in the convalescent and late convalescent period. Since all these categories of antibodies seem to persist for long periods, antibodies against the G1 epitope and the NP epitope may be of specific diagnostic value. Furthermore, levels of G1-specific antibodies and antibodies to either NP or G2 may allow estimation of the time elapsed following initial infection.

Antibodies, Viral↗

Identification of Hantavirus serotypes by testing of post-infection sera in immunofluorescence and enzyme-linked immunosorbent assays.

Serum samples were collected from 27 individuals who had been infected with a member of the genus Hantavirus in the Netherlands or Belgium during the last 15 years. These samples were tested in an immunofluorescence assay (IFA) and two enzyme-linked immunosorbent assay (ELISA) systems, using different virus strains that represented each of the four recently proposed serotypes of this genus. The serum samples from 11 individuals who had been infected through contacts with laboratory rats showed the highest reactivities with Hantaan virus (serotype I) and SR-11 (serotype II) in the IFA and ELISA systems. The samples of 16 individuals who had probably been infected through contacts with wild rodents showed the highest reactivities with Hällnäs virus (serotype III) in the IFA. All except two of these also showed the highest reactivity with Hällnäs virus in the two different ELISA systems.

Antibodies, Viral↗

Expression of the structural proteins of dengue 2 virus and yellow fever virus by recombinant vaccinia viruses.

Vaccinia virus recombinants were constructed which contained cDNA sequences encoding the structural region of dengue 2 virus (PR159/S1 strain) or yellow fever virus (17D strain). The flavivirus cDNA sequences were expressed under the control of the vaccinia 7.5k early/late promotor. Cultured cells infected with these recombinants expressed immunologically reactive flavivirus structural proteins, precursor prM and E. These proteins appeared to be cleaved and glycosylated properly since they comigrated with the authentic proteins from dengue 2 virus- and yellow fever virus-infected cells. Mice immunized with the dengue/vaccinia recombinant showed a dengue-specific immune response that included low levels of neutralizing antibodies. Immunization of mice with the yellow fever/vaccinia recombinant was less effective at inducing an immune response to yellow fever virus and in only some of the mice were low titers of neutralizing antibodies produced.

Amino Acid Sequence↗

Nonstructural proteins nsP3 and nsP4 of Ross River and O'Nyong-nyong viruses: sequence and comparison with those of other alphaviruses.

We have sequenced the nsP3 and nsP4 region of two alphaviruses, Ross River virus and O'Nyong-nyong virus, in order to examine these viruses for the presence or absence of an opal termination codon present between nsP3 and nsP4 in many alphaviruses. We found that Ross River virus possesses an in-phase opal termination codon between nsP3 and nsP4, whereas in O'Nyong-nyong virus this termination codon is replaced by an arginine codon. Previous studies have shown that two other alphaviruses, Sindbis virus and Middelburg virus, possess an opal termination codon separating nsP3 and nsP4 [E.G. Strauss, C.M. Rice, and J.H. Strauss (1983), Proc. Natl. Acad. Sci. USA 80, 5271-5275], whereas Semliki Forest virus possesses an arginine codon in lieu of the opal codon [K. Takkinen (1986), Nucleic Acids Res. 14, 5667-5682]. Thus, of the five alphaviruses examined to date, three possess the opal codon and two do not. Production of nsP4 requires readthrough of the opal codon in those alphaviruses that possess this termination codon and the function of the termination codon may be to regulate the amount of nsP4 produced. It is an open question then as to whether alphaviruses with no termination codon use other mechanisms to regulate the activity of this gene. The nsP4s of these five alphaviruses are highly conserved, sharing 71-76% amino acid sequence similarity, and all five contain the Gly-Asp-Asp motif found in many RNA virus replicases. The nsP3s are somewhat less conserved, sharing 52-73% amino acid sequence similarity throughout most of the protein, but each possesses a nonconserved C-terminal domain of 134 to 246 amino acids of unknown function.

Alphavirus↗

Hemorrhagic fever with renal syndrome (nephropathia epidemica) in Norway: seroepidemiology 1981-1985.

An indirect fluorescent antibody technique (IFAT) was applied to serologically confirm the clinical diagnosis in 507 nephropathia epidemica (NE) suspected patients. Hantaan virus (HV), the agent of Korean hemorrhagic fever, which is serologically related to the NE agent, was used as antigen. Both IgG and IgM reactions were detected. High levels of IgG antibodies to HV were common, even in the acute phase of illness. Over a 5-year period, a total of 35% of the NE suspected patients revealed antibodies to HV, but this varied considerably in the different years. In 2 endemic areas the serological confirmation of the NE diagnosis was 60%. 82% of the seropositive NE patients lived in 4 endemic areas. The bank vole (Clethrionomys glareolus) was common in all areas and predominant in 2. The wood mouse (Apodemus sylvaticus) was abundant in the other 2. In years with high bank vole population, the number of seropositive NE cases increased, with a peak in October/November. When the bank vole population was low, the relatively few seropositive NE cases occurred more regularly throughout the year. Subclinical infections were common. Antibodies to HV were detected in 74% male and 26% female NE patients, but the ratio varied between age groups.

Adult↗

An epidemiological survey of nephropathia epidemica in Sweden.

The indirect immunofluorescence test (IFT) using the Hantaan virus (agent of Korean hemorrhagic fever, KHF) was applied for detection of antibodies to nephropathia epidemica (NE). From 103 patients with symptoms suggesting NE, 61% revealed KHF/NE antibodies in the convalescent sera. All seropositive patients seemed to have acquired their disease in NE endemic areas (north of the 60th parallel). Only patients found to have a typical clinical NE (fever, abdominal pain and renal engagement) were seropositive. Antibodies to KHF/NE were found in 4.2% of sera from 647 healthy persons living in NE endemic areas. Signs of local clusters were found. Subclinical or mild disease seems common. Proof of man to man spread of the disease was not found. Sera from 355 persons living outside NE endemic areas were also tested and 2.4% contained KHF/NE antibodies.

Adolescent↗

Characterization of the viral RNA species of prototype dengue viruses.

Dengue virus isolates have been grown in the Igarashi clone C6/36 Aedes albopictus cells in amounts suitable for biochemical studies. Oligonucleotide fingerprint analyses have been used to characterize the virion 40 S RNA species of the four prototype dengue (DEN) serotype viruses: DEN 1, Hawaiian strain; DEN 2, New Guinea C strain (both insect and mouse brain passaged derivatives); DEN 3, H-87 strain; and DEN 4, H-241 strain. Comparisons of the largest oligonucleotides derived by ribonuclease T1 digestion of these 40 S DEN virion RNA species indicate that ther are few, if any, large oligonucleotides that are homologous between any two fo the four dengue prototype strains. Preliminary analyses of the 40 S RNA 5' terminal sequence of DEN 3 virion RNA indicate that it has the composition of m7GpppAmpXp.

Aedes↗

Biochemical studies on the Phlebotomus fever group viruses (Bunyaviridae family).

Analyses of the virion polypeptides and genomes of several Phlebotomus fever group viruses, Karimabad, Punta Toro, Chagres, and the sandfly fever Sicilian serotype viruses, have established that they are biochemically similar to the accepted members of the Bunyaviridae family. Like snowshoe hare virus (a member of the California serogroup of the Bunyavirus genus of the Bunyaviridae family), Karimabad, Punta Toro, Chagres, and the sandfly fever Sicilian serotype viruses all have three viral RNA species, designated large (L), medium (M), and small (S). Oligonucleotide fingerprint analyses of Karimabad and Punta Toro virus RNA species indicated that their L, M, and S RNA species are unique. By polyacrylamide gel electrophoresis it was determined for Karimabad virus that the apparent molecular weights of its L, M, and S RNA species are 2.6 X 10(6), 2.2 X 10(6), and 0.8 X 10(6), respectively. For Punta Toro virus, the apparent molecular weights of its L, M, and S RNA species are 2.8 X 10(6), 1.8 X 10(6), and 0.75 X 10(6), respectively. The major internal nucleocapsid (N) protein of Karimabad virus was found to have a molecular weight of 21 X 10(3). A similar polypeptide size class was identified in preparations of sandfly fever Sicilian serotype, Chagres, and Punta Toro viruses. The Karimabad virus glycoproteins formed the external surface projections on virus particles and could be removed from virus preparations by protease treatment. The glycoproteins in an unreduced sample could be resolved into two size classes by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. They had apparent molecular weights of 62 X 10(3) and 50 X 10(3) in continuous polyacrylamide gels. When Karimabad virus preparations were reduced with 1% beta-mercaptoethanol, prior to resolution by continuous polyacrylamide gel electrophoresis, all the viral glycoprotein was recovered in a single size class, having an apparent molecular weight of 62 X 10(3). Two or three major virion polypeptides have been identified in preparations of Punta Toro, Chagres, and sandfly fever Sicilian serotype viruses.

Arboviruses↗