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Biomedical subjects

L Ostergaard

Publications and source records attributed to L Ostergaard.

10 recordsLinked to original sources
PubMed1992

Affinity purification of antigen-specific serum immunoglobulin from the European eel (Anguilla anguilla).

Immunization of specimens of the European eel with a hapten-carrier conjugate resulted in a significant rise in anti-hapten titres. Antigen-specific immunoglobulin was purified on a matrix onto which the hapten-carrier conjugate had been immobilized. Rabbit antisera raised against the product of the affinity purification recognized two molecular moieties. The first was eel immunoglobulin as inferred by the polypeptide composition, i.e. disulphide-linked heavy and light chains of 72 kDa and 25 kDa respectively. The second was a 110-kDa protein. A 800-kDa and a 400-kDa molecular form of eel immunoglobulin were disclosed by a combination of gel filtration and immunoelectrophoretic detection. The latter was the more abundant serum form. The 110-kDa protein was found non-covalently associated with the 400-kDa immunoglobulin. Both molecular forms of immunoglobulin from immune sera exhibited antigenic specificity and reactivity.

Anguilla↗
PubMed1991

Evaluation of urogenital Chlamydia trachomatis infections by cell culture and the polymerase chain reaction using a closed system.

Two hundred and fifty-four specimens from males and females consulting a clinic for sexually transmitted diseases were analyzed for genital Chlamydia trachomatis infection. Each clinical sample was tested by the cell culture technique and the polymerase chain reaction using a closed system. When the two test systems were compared, the overall sensitivity of the polymerase chain reaction was 96% and the specificity 94% when compared to the cell culture technique. By use of a closed system for DNA extraction and sample transfer for the polymerase chain reaction, contamination of the samples was minimized. The polymerase chain reaction detected a higher number of Chlamydia trachomatis infections among both symptomatic and asymptomatic females and males, and it also detected Chlamydia trachomatis at an earlier stage of infection when compared to cell culture. The polymerase chain reaction did not detect Chlamydia trachomatis after sufficient antibiotic treatment of the chlamydial infections.

Base Sequence↗
PubMed1990

Age and sex correlation of Chlamydia trachomatis infections evaluated by the culture technique and by an enzyme immunosorbent assay, IDEIA.

A total number of 1358 patients were examined for genital infections with Chlamydia trachomatis. 252 urethral smears from men and 1106 cervical smears from women were obtained. The average age of infected patients was 24.8 years (females 24.1, males 27.7). The overall prevalence was 10.6% (females 10.0%, males 13.1%). At the age below 20 years, the prevalence was 21% for both women and men, and 25% when data were restricted to patients consulting general practitioners. Above that age the overall prevalence was lower in all age intervals, and higher among males than females. All samples were tested by the tissue-culture technique, and the results were confirmed by the IDEIA (Boots-Celltech) enzyme-linked immunosorbent assay kit (EIA) for detection of C. trachomatis. The original smear was used for both culture and EIA. The EIA test was evaluated to have a sensitivity of 90.8% and a specificity of 95.4% when using a cut-off level of 0.05 mean extinction values (MEV), as described by the manufacturer.

Adult↗
PubMed1990

Use of polymerase chain reaction for detection of Chlamydia trachomatis.

A polymerase chain reaction (PCR) assay was developed for detection of Chlamydia trachomatis DNA. From the published sequence of the common C. trachomatis plasmid, two primer sets were selected. Detection of amplified sequences was done by agarose gel electrophoresis of cleaved or uncleaved amplified sequences, Southern hybridization, or dot blot analysis. The PCR assay was optimized and, after 40 cycles of amplification with primer set II, demonstrated a sensitivity of 10(-17) g of DNA, which corresponds to the detection of one copy of the plasmid. Because of the high sensitivity, we developed a closed system in which airborne contamination was minimized. Analysis of 228 clinical samples tested by cell culture, IDEIA enzyme immunosorbent assay (Medico-Nobel, Boots-Celltech Ltd., Berkshire, United Kingdom), and PCR showed a sensitivity of 100%, a specificity of 93% when PCR was compared with cell culture, and a corrected specificity of 99% when PCR was compared with cell culture or IDEIA.

Bacterial Typing Techniques↗
PubMed1990

Rabbit sphincter of Oddi has a certain autonomy: characteristic features.

Simultaneous recordings of electromyography and manometry were obtained from rabbit sphincter of Oddi (SO) and duodenum. Three different patterns of activity were observed in SO and in duodenum: 1) a low-amplitude (less than 3 cm H2O) pattern of background oscillations with 2) superimposed high-amplitude (4-20 cm H2O) contractions and 3) occasional complex contractions consisting of an elevation of the basal pressure with superimposed smaller contractions. A certain SO autonomy was evident: 57.6% of SO pressure peaks could not be assigned to any duodenal activity. The distribution of SO pressure peak amplitudes could not be described by a simple normal distribution. The distribution of SO pressure peak amplitudes with concomitant duodenal activity differed from the overall distribution (p less than 0.001). Whereas a substantial part of SO pressure peaks greater than 4 cm H2O had no or low-amplitude corresponding duodenal pressure activity, duodenal pressure peaks greater than 4 cm H2O almost invariably were associated with SO pressure peaks. It is concluded that rabbit SO does possess a certain autonomy, but at the same time a close functional connection exists between the two compartments.

Ampulla of Vater↗
PubMed1990

Rabbit sphincter of Oddi and duodenum are regulated by slow waves with a common basic-mode activity.

Simultaneous recordings of pressure and slow-wave activity were obtained from the sphincter of Oddi (SO) and the duodenum in anesthetized rabbits. Histographic analysis of the recordings was performed when the following criteria were fulfilled: 1) slow waves must be present in the EMG recordings from both compartments; and 2) only pressure recordings with sufficient pressure activity (greater than 50 peaks in 10 min) would be considered. Of 12 animals fulfilling the criteria for histographic analysis of 4 channels, a common basic-mode activity was found in all channels in 9 animals (75%). Of three animals fulfilling the criteria for histographic analysis of three channels, a common basic-mode activity was seen in all channels in all animals (100%). A correlation between the amplitude of the slow waves and the amplitude of the elicited pressure peaks in the SO was significant at a 5% level or better in 12 animals (80%). In some of the animals episodes of low-amplitude pressure activity was observed in the SO, occurring synchronously with slow waves devoid of spike activity. It is concluded that rabbit SO and duodenum are paced by slow waves with a common basic-mode activity in most animals. Slow waves may not only be the chief determinant of the contractile rhythm but may also have a certain influence on the force of the individual SO contractions. It is suggested that slow waves per se may be able to mediate contractile activity.

Ampulla of Vater↗
PubMed1989

[Oddi's sphincter dysfunction].

Dysfunction of the sphincter of Oddi (SOD) is an uncommon condition which must be considered in cases of persistent pain in the upper abdomen following uncomplicated cholecystectomy, when disease in other organs, such as gastric ulcer, esophagitis and pancreatitis has been eliminated. The pathogenesis is not fully elucidated, but it is assumed that the cholecystectomy in some cases induces an increased tendency to spasm in the sphincter of Oddi (SO), and, perhaps in connection with an increased sensitivity to pressure elevations in the biliary tree, results in attacks of pain. Whether fibrosis (stenosis) of the SO due to instrumentation or passage of stones is part of the etiology is obscure. Endoscopic retrograde cholangiopancreaticography with papillary manometry should be performed in all cases where SOD is suspected. An elevated basal pressure in SO seems to be the best indicator of SOD. In cases unresponsive to conservative treatment, endoscopic sphincterotomy may be considered. This treatment is not finally evaluated, but apparently the effect is good, especially in patients with elevated basal pressure in SO. It is emphasized that the knowledge of the behavior and regulation of SO is incomplete and that this should be remembered when criteria for SOD are applied.

Ampulla of Vater↗
PubMed1988

A model for simultaneous study of pressure and electric events in the rabbit sphincter of Oddi and duodenum.

An animal experimental model featuring simultaneous recordings of electromyography and pressure from the sphincter of Oddi (SO) and duodenum is demonstrated. On the basis of data from 10 rabbits, pressure recordings from the SO were shown to have phasic activity with an average basic pressure peak interval of 2.6 to 3.5 sec. Histographic analysis of SO pressure recordings showed a multimodal appearance, suggesting that the activity is paced. A substantial amount of overlap between SO and duodenal contractions was observed. As many as 30% of the pressure peaks recorded from the SO could not be assigned to a spike complex in the corresponding EMG tracings. It is suggested that combined recordings of EMG and pressure activity are needed to characterize fully the motility of the SO and duodenum.

Ampulla of Vater↗
PubMed1987

Evolutionary relationships amongst archaebacteria. A comparative study of 23 S ribosomal RNAs of a sulphur-dependent extreme thermophile, an extreme halophile and a thermophilic methanogen.

The 23 S RNA genes representative of each of the main archaebacterial subkingdoms, Desulfurococcus mobilis an extreme thermophile, Halococcus morrhuae an extreme halophile and Methanobacterium thermoautotrophicum a thermophilic methanogen, were cloned and sequenced. The inferred RNA sequences were aligned with all the available 23 S-like RNAs of other archaebacteria, eubacteria/chloroplasts and the cytoplasm of eukaryotes. Universal secondary structural models containing six major structural domains were refined, and extended, using the sequence comparison approach. Much of the present structure was confirmed but six new helices were added, including one that also exists in the eukaryotic 5.8 S RNA, and extensions were made to several existing helices. The data throw doubt on whether the 5' and 3' ends of the 23 S RNA interact, since no stable helix can form in either the extreme thermophile or the methanogen RNA. A few secondary structural features, specific to the archaebacterial RNAs were identified; two of these were supported by a comparison of the archaebacterial RNA sequences, and experimentally, using chemical and ribonuclease probes. Seven tertiary structural interactions, common to all 23 S-like RNAs, were predicted within unpaired regions of the secondary structural model on the basis of co-variation of nucleotide pairs; two lie in the region of the 23 S RNA corresponding to 5.8 S RNA but they are not conserved in the latter. The flanking sequences of each of the RNAs could base-pair to form long RNA processing stems. They were not conserved in sequence but each exhibited a secondary structural feature that is common to all the archaebacterial stems for both 16 S and 23 S RNAs and constitutes a processing site. Kingdom-specific nucleotides have been identified that are associated with antibiotic binding sites at functional centres in 23 S-like RNAs: in the peptidyl transferase centre (erythromycin-domain V) the archaebacterial RNAs classify with the eukaryotic RNAs; at the elongation factor-dependent GTPase centre (thiostrepton-domain II) they fall with the eubacteria, and at the putative amino acyl tRNA site (alpha-sarcin-domain VI) they resemble eukaryotes. Two of the proposed tertiary interactions offer a structural explanation for how functional coupling of domains II and V occurs at the peptidyl transferase centre. Phylogenetic trees were constructed for the archaebacterial kingdom, and for the other two kingdoms, on the basis of the aligned 23 S-like RNA sequences.(ABSTRACT TRUNCATED AT 400 WORDS)

Archaea↗