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Biomedical subjects

C Seifert

Publications and source records attributed to C Seifert.

At least 19 recordsLinked to original sources
PubMed2003

Is HSV serology useful for the management of first episode genital herpes?

BACKGROUND: First episode genital herpes simplex virus (HSV) infections can be classified into three groups, primary genital herpes (no previous exposure to HSV), non-primary first episode (IgG antibody to HSV of the non-presenting type), and first episode with pre-existing IgG HSV antibodies. The use of IgM to classify first episode genital herpes has not been evaluated. OBJECTIVE: To evaluate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of HSV-1 and HSV-2 IgM antibodies for the diagnosis of first episode genital herpes, when compared with clinical diagnosis. METHODS: Patients with a first clinical episode of genital herpes were recruited. Sera were tested for IgG antibodies to HSV-2 using an indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. HSV-1 IgG and IgM and HSV-2 IgM antibodies were detected using western blot. RESULTS: 157 patients were recruited. 31 were excluded (missing data or no detectable antibodies and negative viral isolation). Therefore, 126 patients were included in the analysis. 23 (18.3%) had primary genital herpes, 34 (27.0%) non-primary first episode, and 69 (54.8%) had pre-existing genital herpes. The specificity and PPV of HSV IgM was 100%; the sensitivity was 79% and the NPV 85%. CONCLUSION: IgM HSV serology may be useful in the management of some patients with first episode genital herpes and provide an indication of the source of infection. Drawbacks include the low sensitivity and NPV, lack of availability, IgM antibodies may occasionally be produced in response to recurrent infection and, finally, IgM antibodies may take up to 10 days to develop and last 7-10 days.

Antibodies, Viral↗
PubMed2003

Sexual behaviour and social class in Australian women.

Sexual behaviour is determined by social, cultural and personal factors. Sexual behaviour studies have been conducted in many countries. However, information from Australia is limited. This study was conducted in Obstetrics Department, Westmead Hospital, Sydney. Questionnaire-derived demographic and behavioural characteristics for public and private patients were compared using bivariate and logistic regression analyses. Of the patients, 3036 were public, and 595 private. On bivariate analysis some significant differences were private patients more likely to be born in Australia and have a higher education level whereas public patients were more likely to have had a greater number of lifetime sexual partners and younger age at first sex. Public patients were more likely to be herpes simplex virus type 2 (HSV-2) antibody positive (12%) than private patients (6%). On logistic regression significant variables included country of birth, being HSV-2 antibody positive, and age at first sex. A number of sexual and social variables were significantly different, comparing patients in the public and private sectors. Evaluation of interventions to reduce the sexual risk to women in the public sector should be considered, including encouraging young women to delay their sexual debut, and reducing the number of sexual partners.

Adolescent↗
PubMed2001

Resident interpretation of emergency CT scans in the evaluation of acute appendicitis.

PURPOSE: Radiology resident interpretation of computed tomographic (CT) scans at academic institutions often guides management of cases of suspected acute appendicitis in the emergency department. The purpose of this study was to compare resident and faculty interpretation of CT scans obtained for acute appendicitis. MATERIALS AND METHODS: From December 16, 1999, to July 13, 2000, CT was performed in 103 consecutive patients between the hours of 9:00 PM and 8:00 AM who were suspected of having acute appendicitis. The authors compared the residents' preliminary written interpretations with both the final reports written by the faculty and the surgical findings. The faculty interpreting the CT scans were aware of resident interpretations but were not aware that a study was being conducted. RESULTS: The final faculty interpretation and the preliminary resident interpretation were identical in 96 of the 103 patients (93%; 95% confidence interval: 87.8%, 97.2%). In only one patient was a scan originally interpreted as negative interpreted as positive by the faculty member. Clinically, the patient did not have acute appendicitis, and surgery was not perforrmed. CONCLUSION: In the diagnosis of acute appendicitis, image interpretations made by adequately trained radiology residents can be expected to closely match those of the radiology faculty, and the practice of after-hours interpretation of such studies by radiology residents is safe.

Acute Disease↗
PubMed2001

Identification and expression of the genes and purification and characterization of the gene products involved in reactivation of coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii.

The coenzyme B12-dependent glycerol dehydratase of Citrobacter freundii is subject to suicide inactivation by the natural substrate glycerol during catalysis. We identified dhaF and dhaG as the genes responsible for reactivation of inactivated dehydratase. Northern blot analyses revealed that both genes were expressed during glycerol fermentation. The dhaF gene is transcribed together with the three structural genes coding for glycerol dehydratase (dhaBCE), whereas dhaG is coexpressed with the dhaT gene encoding 1,3-propanediol dehydrogenase. The dhaF and dhaG gene products were copurified to homogeneity from cell-free extracts of a recombinant E. coli strain producing both His6-tagged proteins. Both proteins formed a tight complex with an apparent molecular mass of 150 000 Da. The subunit structure of the native complex is probably alpha2beta2. The factor rapidly reactivated glycerol- or O2-inactivated hologlycerol dehydratase and activated the enzyme-cyanocobalamin complex in the presence of coenzyme B12, ATP, and Mg2+. The DhaF-DhaG complex and DhaF exhibited ATP-hydrolyzing activity, which was not directly linked to the reactivation of dehydratase. The purified DhaF-DhaG complex of C. freundii efficiently cross-activated the enzyme-cyanocobalamin complex and the glycerol-inactivated glycerol dehydratase of Klebsiella pneumoniae. It was not effective with respect to the glycerol dehydratase of Clostridium pasteurianum and to diol dehydratases of enteric bacteria.

Adenosine Triphosphatases↗
PubMed2001

Sexual and demographic risk factors for herpes simplex type 1 and 2 in women attending an antenatal clinic.

OBJECTIVE: To establish risk factors for the presence of HSV-2 and HSV-1 infections in pregnant women. DESIGN, POPULATION, AND SETTING: A prospective study of 3306 women attending the antenatal department Westmead Hospital, Sydney, between June 1995 and April 1998. METHODS: Women completed a self administered questionnaire to establish risk factors for the presence of HSV-2 and HSV-1. Sera were tested for antibodies to HSV-2 and HSV-1. Data were analysed using SPSS and SAS. MAIN OUTCOME MEASURES: Seroprevalence of and risk factors for HSV-2 and HSV-1. RESULTS: 375 (11.3% (95% CI 10.3-12.5)) women were HSV-2 antibody positive. Increasing age, Asian country of birth, lower education level, public hospital status, confirmed genital herpes, a partner with genital herpes, early age of first sex, more than one lifetime sexual partner, and previous chlamydia infection were independently associated with HSV-2 seropositivity. Of 408 women tested for HSV-1 antibodies, 323 (79.2% (95% CI 74.9-83.0)) were positive. Oral herpes, oral blisters or sores, and being HSV-2 seropositive were independently associated with HSV-1 seropositive status. When the logistic regression model was rerun without HSV-2 status, parity of two or more and one or more sexual partners in the past 3 months were significant predictors of HSV-1 seropositivity. CONCLUSIONS: The presence of antibodies to HSV-2 and HSV-1 is related to a number of sexual and demographic risk factors. Public health campaigns directed at encouraging young people to delay the onset of sexual activity and reduce the number of sexual partners need to be evaluated. However, the possible availability of an HSV-2 vaccine that is able to protect over 70% of women offers the best hope for control of genital herpes.

Adolescent↗
PubMed2000

Nociceptive fingertip stimulation inhibits synergistic motoneuron pools in the human upper limb.

BACKGROUND: Activation of distinct muscle groups organized in a stereotyped manner ("muscle synergies") is thought to underlie the production of movement by the vertebrate spinal cord. This results in movement with minimum effort and maximum efficiency. The question of how the vertebrate nervous system inhibits ongoing muscle activity is central to the study of the neural control of movement. OBJECTIVE: To investigate the strategy used by the human spinal cord to rapidly inhibit muscle activation in the upper limb. METHODS: The authors performed a series of experiments in 10 healthy subjects to assess the effect of nociceptive cutaneous stimulation on voluntarily contracting upper limb muscles. They recorded the electromyogram (EMG) with surface electrodes placed over various upper limb muscles. RESULTS: The authors found evidence of a simple inhibitory strategy that 1) was dependent on the intensity of the stimulus, 2) was maximally evoked when stimulation was applied to the fingertips, 3) preceded the earliest onset of voluntary muscle relaxation, and 4) produced inhibition of EMG activity in specific upper limb muscle groups. Nociceptive fingertip stimulation preferentially inhibited contraction of synergistic muscles involved in reaching and grasping (intrinsic hand muscles, forearm flexors, triceps) while having little effect on biceps or deltoid. CONCLUSIONS: Neural circuitry within the human spinal cord is organized to inhibit movement by rapidly deactivating muscles that constitute distinct muscle synergies. This strategy of selective and concurrent deactivation of the same basic elements that produce synergistic movement greatly simplifies motor control.

Adult↗
PubMed2000

Alterations of preliminary readings on radiographic examinations minimally affect outcomes of trauma patients discharged from the emergency department.

BACKGROUND: We hypothesized that trauma patients could be discharged safely from the emergency department (ED) before the availability of official readings for their radiologic examinations. We also sought to determine whether trauma patients were more prone to alterations of preliminary interpretations than other ED patients. METHODS: Alterations of preliminary readings (PR) for patients discharged from the ED were reviewed. If the official readings conflicted with the PR used for the patient's disposition, attempts were made to contact the patient and provide the appropriate follow-up. Data recorded included the type of radiographic examination, the presence of a missed injury, and the follow-up. By using institutional data, the incidence of inaccurate PR were compared for trauma patients and other ED patients (chi2 test, Fisher exact test, p < 0.05). RESULTS: Between January of 1998 and December of 1998, 102 of 38,260 discharged ED patients had official readings differing from PR. Forty-three of the changed readings involved 42 of the 1,073 discharged trauma patients, who were more likely to harbor inaccurate PR (<0.0001) than other discharged ED patients. Twenty-eight altered readings involved plain films and 15 involved computed tomographic scans. The most common altered readings involved computed tomographic scans of the head and face (n = 13). Twelve missed injuries were detected, most commonly related to a missed injury of the extremity (7 cases). Nine other cases involved the detection of incidental pathologic conditions. Eight patients required repeat ED visits for clinical and radiographic evaluation, and one patient required subsequent hospital admission. CONCLUSION: Discharged trauma patients are more likely to harbor alterations of preliminary interpretations than other ED patients. Although the official readings for these trauma patients will occasionally reveal previously undetected pathologic conditions, the majority of such cases can be managed with outpatient follow-up.

Diagnostic Errors↗
PubMed2000

Neonatal herpes prevention: a minor public health problem in some communities.

BACKGROUND: Neonatal herpes is a condition with high morbidity and mortality. The greatest risk occurs when the mother acquires herpes simplex virus (HSV) towards the end of pregnancy. A study from Seattle has suggested that the risk of acquisition of HSV during pregnancy was 3.7%. In Australia, HSV-2 infection is less common in pregnant women than in the United States. Consequently we conducted a study to establish HSV seroprevalence and the rate of HSV seroconversion in this population. METHODS: The study was conducted at Westmead Hospital, Sydney, between June 1995 and April 1998. Women completed a questionnaire covering risk factors for the acquisition of genital herpes. A serum sample during pregnancy and a specimen of cord blood were obtained and tested for antibodies to HSV-2 using a type specific indirect enzyme linked immunosorbent assay (ELISA). Equivocal results were resolved by western blot. A subset of the paired sera was tested for antibodies to HSV-1. The data were analysed using SPSS. RESULTS: 326 of the 2616 (12.5%) women were HSV-2 seropositive. Three women (0.15%) acquired HSV-2 infection during pregnancy. None of the three babies of these mothers developed neonatal herpes. 416 maternal cord pairs were tested for HSV-1 antibodies and 330 (79.3%) were positive. No HSV-1 seroconversions occurred. CONCLUSIONS: In this population, HSV acquisition was uncommon (0.34% per year) and neonatal herpes was rare. A cost effective analysis suggested that type specific serology to screen pregnant women and their partners in low prevalence communities was not cost effective.

Adult↗
PubMed1999

Facial palsy in Heerfordt's syndrome: electrophysiological localization of the lesion.

Heerfordt's syndrome is characterized by fever, uveitis, swelling of the parotid gland, and facial nerve palsy and represents a variety of neurosarcoidosis. Since the first description of the syndrome, discussion about the lesion site has been controversial and has included the assumption of direct nerve compression by parotid gland swelling or a lesion within the facial canal in light of observations of accompanying taste disturbance. We report on a 26-year-old man with typical Heerfordt's syndrome who developed bilateral facial nerve palsy. Electrical and magnetic stimulation of the whole facial motor path provided strong evidence for a pathological process that: (i) began in the cerebellopontine angle; (ii) spread distally into the facial canal; and (iii) could be characterized by proximal demyelination. The patient recovered completely within 6 weeks under immunosuppressive therapy with steroids.

Adult↗
PubMed1999

Carbon dioxide storage and nonbicarbonate buffering in the human body before and after an Himalayan expedition.

Before and 7-12 days after an Himalayan expedition CO2 equilibration curves were determined in the blood plasma of 12 mountaineers by in vitro and in vivo CO2 titration; in vivo osmolality changes (delta Osm x deltaPCO2(-1), deltaOsm x delta pH(-1), where PCO2 is the partial pressure of CO2) during the latter experiments yielded estimates of whole body CO2 storage. In vitro -delta[HCO3-] x delta pH(-1) [nonbicarbonate buffer capacity (beta) of blood] was increased 7 days after descent [before 31.3 (SEM 0.4) mmol x kgH2O(-1), after 38.3 (SEM 3.9) mmol x kgH2O(-1); P<0.05] resulting from an increased proportion of young erythrocytes; in additional experiments an augmented beta was found in young (low density cells) compared to old cells [<1.097 g x ml(-1): 0.216 (SEM 0.028) mmol x gHb(-1), >1.100 g x ml(-1): 0.145 (SEM 0.013) mmol x gHb(-1), where Hb is haemoglobin; P < 0.02]. In spite of increased Hb mass in vivo delta[CO2total] x deltaPCO2(-1) [0.192 (SEM 0.010) mmol x kgH2O(-1) x mmHg(-1)] and -delta[HCO3-] x delta pH(-1) [17.9 (SEM 1.0) mmol x kgH2O(-1)] as indicators of extracellular beta rose only slightly after altitude (7 days +16%, P<0.02; +7%, NS) because of haemodilution. The deltaOsm x deltaPCO2(-1) [0.230 (SEM 0.015) mosmol x kgH2O(-1) x mmHg(-1)] remained unchanged. Prealtitude differences in deltaOsm x delta pH(-1) between hypercapnia [-41 (SEM 5) mosmol x kgH2O(-1)] and hypocapnia [-20 (SEM 3) mosmol x kgH2O(-1); P<0.01] disappeared temporarily after return since the former slope was reduced. The high value during hypercapnia before ascent probably resulted from mechanisms stabilizing intracellular pH during moderate hypercapnia which were attenuated after descent.

Acclimatization↗
PubMed1998

Modulation of upper extremity motoneurone excitability following noxious finger tip stimulation in man: a study with transcranial magnetic stimulation.

Little is known about nociceptive reflex mechanisms in the upper limb in humans. To investigate nociceptive effects on spinal motoneurone excitability, a conditioning noxious stimulus was applied to the index finger of five healthy subjects. Motor evoked potentials (MEPs) following contralateral transcranial magnetic stimulation (TMS) were recorded from thenar eminence (TE) and biceps brachii (BB) muscles ipsilateral to finger stimulation. TMS was randomly applied alone or combined with preceding finger stimulation at an interstimulus interval of 100 ms. MEP amplitudes were profoundly suppressed in TE and augmented in BB. We conclude that nociception produces a differential effect on different spinal motoneurone pools, which may be part of a complex protective reflex mechanism in the upper limb of humans.

Adult↗
PubMed1995

Bone scintigraphy: an aid in deciding on the extent of bone resection in malignant oral tumors.

PURPOSE: The decision of whether to perform continuity-sparing or resecting surgery of the jaw in cases of malignant oral tumors is often difficult. PATIENTS AND METHODS: To aid in this decision, bone scintigraphy was evaluated retrospectively in 304 patients with a squamous cell carcinoma. RESULTS: One hundred forty-five patients showed no accumulation of the radionuclide, and none of them had infiltration by tumor histologically. CONCLUSION: It was concluded that a bone-sparing resection of tumors close to the jaw may be justified when there is a negative bone scan.

Adenocarcinoma↗
PubMed1995

Reasoning about curvilinear motion: using principles or analogy.

People possess implicit theories about the motion of objects, theories that are often incorrect. When asked to predict the path of an object emerging from a curved tube, for example, people often say that the object will continue to follow a curved path. However, when solving a problem that reminds them of a familiar previous instance, people often reason by analogy to the instance. In this study, we show that a previous instance must be very superficially similar to a problem in order to be used as an analogy; otherwise, people will use their implicit theories as the basis of their reasoning.

Adult↗
PubMed1992

Reciprocal inhibition of forearm flexor muscles in spasmodic torticollis.

Reciprocal inhibition between forearm extensor and flexor muscles was tested by means of an H-reflex technique in patients with spasmodic torticollis and normal controls. In both, patients and controls three different phases of reciprocal inhibition could be demonstrated with maximal inhibition at conditioning test intervals of 0 ms, 15 ms and 100 ms, respectively. However, the quantitative amount of this inhibition was different for the patients and the controls. Significantly less inhibition was found for the second and the third phase of reciprocal inhibition in the patient group. Discriminant analysis showed a clear separation between normal subjects and patients if the amount of reciprocal inhibition of the second and third phase were taken into account. We were not able to detect any side differences neither for the patients nor for the controls. The findings demonstrate a functional disturbance of motor control mechanisms of a clinically unaffected extremity in spasmodic torticollis. This is believed to reflect a bilateral disturbance most likely within the basal ganglia or their outflow. Therefore, our data support the idea, that spasmodic torticollis is associated with or even due to a generalized rather than a focal disturbance of motor control mechanisms.

Analysis of Variance↗
PubMed1989

[Endoscopic-radiologic diagnosis and therapy of the bile ducts. Results of endoscopic papillotomy].

Endoscopic-radiologic methods for demonstrating the hepatobiliary and pancreatic ducts are an integrated part of the diagnostic spectrum of gastroenterologic centers. At the Charité since 1975 we have made more than 5,500 endoscopic-retrograde cholangio-pancreaticographies (ERCP's). This method provides immediately or later an adequate therapy as an alternative to the otherwise necessary surgery. The most frequently used and basic method is endoscopic papillotomy (EPT). In most cases it precedes endoscopic removal of concrements, prosthetic drainage of biliary pathways or extracorporal shockwave lithotripsy (ESWL). Since 1977 we have carried out 2,050 EPT's at the Charité, more than 60% of these for patients of higher age (above 60). With 98.3% successful interventions complications were seen in only 4.7% of the cases. The influence of close interdisciplinary cooperation of endoscopicists and radiologists on the results of the investigation and the rate of complications is discussed.

Adult↗
PubMed1986

[Noninvasive roentgen diagnosis of right heart function in patients with recirculation disorders and chronic nonspecific lung changes].

The non-invasive x-ray functional diagnostic electroradiographic method at the large vessels near the heart may enrich the radiological preliminary diagnostics of recirculation abnormalities. In chronic unspecific pulmonary diseases it can characterize the load of the right heart. Our studies should serve as a pilot study for the in future possible, simply to be handled non-invasive video-densitometry of the vessels near the heart in the preliminary diagnostics of cardiovascular diseases.

Cardiac Output↗
PubMed1986

A summertime peak of Down's syndrome in Franklin County, Ohio.

In June, July, and August of 1984, more infants than usual were born with Down's syndrome in Franklin County, Ohio. A direct physician survey was done, and chromosome reports were reviewed, resulting in the identification of 11 infants with Down's syndrome born during that period. Using a chi 2 analysis, the expected number of affected newborns was five, making the actual number of 11 significant. Although a summertime peak was observed, the yearly incidence of 1.09 per 1000 live births was within the expected range.

Adolescent↗