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Biomedical subjects

J Helle

Publications and source records attributed to J Helle.

11 recordsLinked to original sources
PubMed2005

Transmission of hepatitis B in Hamburg, Germany, 1998-2002: a prospective, population-based study.

To study the pattern of transmission of HBV in a large urban community, an in-depth prospective study was performed in Hamburg between 1 January 1998 and 31 December 2002. In total, 524 patients were classified as hepatitis B cases according to the case definition of the Robert Koch Institute, comprising 197 foreign-born and 327 German-born persons. The principal risk factor was parenteral drug use, with 17.7% (n=93/524) of all documented cases of hepatitis B, followed by immigration as refugees (13.9%; n=73). Of all 524 cases, 72 (13.7%) were associated with heterosexual (n=41) or homosexual (n=31) transmission. Household contacts of HBV carriers or of patients with acute infectious disease contributed to 9.0% of the cases (n=47). Medical procedures were most probably the source in 7.4% (n=39), although only 3.2% (n=17) of all patients were health-care workers. In multivariate analysis of household contacts, male-male sexual activity was found to be the greatest risk factor for acquiring an acute HBV infection, followed by asylum-seeking status and the number of contacts. The incidence was 3.5-fold higher among foreign-born persons (16.1 per 100,000) than among German-born individuals (4.5 per 100,000) suggesting that a targeted intervention in this population group is a public-health need. The current national policy of vaccination in defined age groups should be extended to the immunization of all children of foreign-born parents as well as the screening and immunisation of susceptible foreign-born adults.

Adolescent↗
PubMed2002

Development and applications of injectable poly(ortho esters) for pain control and periodontal treatment.

Poly(ortho esters) with a low glass transition temperature are semi-solid materials so that therapeutic agents can be incorporated at room temperature, without the use of solvents, by a simple mixing procedure. When molecular weights are limited to < 5 kDa, such materials are directly injectable using a needle size no larger than 22 gauge. Somewhat hydrophilic polymers can be produced by using the diketene acetal 3,9-diethylidene-2,4,8,10-tetraoxaspiro[5.5]undecane and triethylene glycol (TEG), while hydrophobic materials can be produced by using the diketene acetal and 1,10-decanediol. Molecular weight can be reproducibly controlled by using an excess of the diol, or by use of an alcohol that acts as a chain-stopper. Erosion rates can be controlled by varying the amount of latent acid incorporated into the polymer backbone. Toxicology studies using the TEG polymer have been completed and have shown that the polymer is non-toxic. Toxicology studies using the decanediol polymer are underway. Development studies using the TEG polymer aimed at providing a sustained delivery of an analgesic agent to control post-surgical pain are under development and human clinical trials using the decanediol polymer for the treatment of periodontitis are also underway.

Anesthetics, Local↗
PubMed1996

The distribution of histamine-immunoreactive neurons in the ventral nerve cord of the cricket, Gryllus bimaculatus.

The present study demonstrates the immunocytochemical localisation of the biogenic amine, histamine (HA), in interneurons within the ventral nerve cord of the cricket, Gryllus bimaculatus. Analysis of whole-mount preparations combined with histology of serial sections reveals a constant number of HA-immunoreactive (HA-ir) neurons in the suboesophageal (n=8), thoracic (n=4) and abdominal ganglia (females/males n=24/20). Except for the suboesophageal and prothoracic ganglion, each thoracic and abdominal neuromere contains one pair of bilateral-symmetric HA-ir somata in a medio-ventral position. Axons from HA-ir cells in the thorax extend anteriorly and share common projection areas in thoracic associative neuropils; they terminate in the brain. HA-ir cells also display efferent descending axons. Extending posteriorly, these axons give rise to varicose HA-ir fibre plexuses on the surface of nerve 1 of the abdominal ganglia. In the suboesophageal ganglion, processes from a bilateral symmetric group of clustered HA-ir cells ascend into the tritocerebrum of the brain and further project into the frontal ganglion and the recurrent nerve. Ultrastructural analysis reveals dense-core vesicles, indicative of non-synaptic secretion, in HA-ir elements within the stomatogastric nervous system. Arborisations of HA-ir neurons are present in all major neuropil regions of the ventral nerve cord and display characteristic varicose structures also detected in other types of amine-containing cells. Central HA-ir varicose projections in dorsal and ventral neuropils are located in close apposition to the ganglionic surface. The wide-spread innervation of all neuromeres by HA-ir interneurons and the identification of possible neurohemal release sites suggest a general role of HA as a neuroactive substance, including neuromodulatory and neurohormonal functions.

Abdomen↗
PubMed1995

Putative neurohemal areas in the peripheral nervous system of an insect, Gryllus bimaculatus, revealed by immunocytochemistry.

The morphology and position of putative neurohemal areas in the peripheral nervous system (ventral nerve cord and retrocerebral complex) of the cricket Gryllus bimaculatus are described. By using antisera to the amines dopamine, histamine, octopamine, and serotonin, and the neuropeptides crustacean cardioactive peptide, FMRFamide, leucokinin 1, and proctolin, an extensive system of varicose fibers has been detected throughout the nerves of all neuromeres, except for nerve 2 of the prothoracic ganglion. Immunoreactive varicose fibers occur mainly in a superficial position at the neurilemma, indicating neurosecretory storage and release of neuroactive compounds. The varicose fibers are projections from central or peripheral neurons that may extend over more than one segment. The peripheral fiber varicosities show segment-specific arrangements for each of the substances investigated. Immunoreactivity to histamine and octopamine is mainly found in the nerves of abdominal segments, whereas serotonin immunoreactivity is concentrated in subesophageal and terminal ganglion nerves. Immunoreactivity to FMRFamide and crustacean cardioactive peptide is widespread throughout all segments. Structures immunoreactive to leucokinin 1 are present in abdominal nerves, and proctolin immunostaining is found in the terminal ganglion and thoracic nerves. Codistribution of peripheral varicose fiber plexuses is regularly seen for amines and peptides, whereas the colocalization of substances in neurons has not been detected for any of the neuroactive compounds investigated. The varicose fiber system is regarded as complementary to the classical neurohemal organs.

Amines↗
PubMed1995

Caffeine influence on the motor steadiness battery in neuropsychological tests.

Caffeine is a widely used drug with various biological effects. The present investigation focuses on a possible influence of caffeine upon motor steadiness performance in tests routinely used in neuropsychological testing. Twenty-four healthy females between 23 and 38 years were investigated in a randomised double-blind crossover study. A significantly poorer motor steadiness performance was found after ingestion of 300 mg of caffeine as compared to a placebo (decaffeinated coffee). Both error time and error count were increased after caffeine consumption. Caffeine also tended to reduce maze coordination test performance. We conclude that caffeine intake preferably should be avoided before neuropsychological testing of motor steadiness.

Adult↗
PubMed1986

[Risk of suicide in the psychiatric clinic in relation to compulsory security guarantees and freedom as adjunct to therapy].

Whereas doctors and nurses in a psychiatric hospital are compelled, on the one hand, to prevent a mental patient from committing suicide (which may entail quite considerable restriction of freedom of movement and action), they may find it necessary on the other hand to grant him a certain amount of freedom as an adjuvant to therapy. It has been said that one may well fear that the compulsion to prevent suicide completely over rules therapy as such, and hence that official legislation is an obstacle to full utilisation of existing chances of cure, since it requires doctors and nurses to prevent suicide as the first and foremost consideration. This fear, however, is unfounded. Rather, the psychiatrist is called upon to weight the suicide risk against the chances of cure under less strict supervision in individual cases that appear suitable for following such a procedure. This conclusion is based on legal theoretical deliberations and is in line with judgements pronounced by Federal German Supreme Courts.

Germany, West↗
PubMed1984

Infection with Campylobacter fetus.

Over a 4-yr period (1978-1982) about 1 000 cases of campylobacter infection were diagnosed at our laboratory in Helsinki, but only 4 proved to be due to Campylobacter fetus. All these 4 patients had fever, 3 had diarrhoea and 1 arthritis and thrombophlebitis. The diagnosis was made from blood cultures in all cases; in 1 case the bacterium was also isolated from stools.

Adult↗
PubMed1983

A quantitative assay for ciliate chemotaxis.

A quantitative bioassay for ciliate chemotaxis based on the capillary principle is described using Tetrahymena thermophila as test organism. The attractant-containing assay tube designed for the bioassay attracts up to 4 X 10(4) cells in 2 h which makes electronic cell counting of the chemotactic response feasible. The attractants used are solutions of proteose peptone and yeast extract which also are growth media for this organism.

Cell Count↗
PubMedDate not supplied

Validity of the schizophrenia diagnosis of the psychopathology instrument for mentally retarded adults (PIMRA): a comparison of schizophrenic patients with and without mental retardation.

The Psychopathology Instrument for Mentally Retarded Adults (PIMRA) was designed to assess psychiatric disorders among mildly and moderately mentally retarded persons. In a psychiatric population without mental retardation (n = 53), the PIMRA schizophrenia scale had an internal consistency coefficient alpha = 0.52. By removing one outlier item this increased to alpha = 0.61. By comparing the PIMRA schizophrenia diagnoses with DSM-III-R diagnoses in the psychiatric population, we found an external reliability corresponding to phi = 0.47 and an unweighted kappa = 0.43. Weighting of the mistakes resulted in a weighted kappa (w) = 0.74. A regression analysis of DSM-III-R diagnosis based on the PIMRA items was conducted. The regression equation was able to identify 75.5% of the DSM-III-R schizophrenic disorders in the psychiatric population. This equation correctly identified 75.5% of the PIMRA schizophrenias in a mentally retarded population. The intermethod reliability was phi = 0.49. We also compared the 38 psychiatric patients with DSM-III-R schizophrenic disorder with the 48 mentally retarded patients with PIMRA schizophrenic disorder. The mentally retarded patients had less delusions and more incoherence and flat affect. They also used less neuroleptic drugs.

Adolescent↗