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Biomedical subjects

M Berg

Publications and source records attributed to M Berg.

At least 91 records · Page 5Linked to original sources
PubMed1998

A phenomenological study of women's experiences of complicated childbirth.

OBJECTIVE: To describe women's experiences of a complicated childbirth. DESIGN: A qualitative study using a phenomenological approach. Data were collected by tape-recorded interviews. SETTING: Sahlgrenska University Hospital, Göteborg, Sweden in 1995. PARTICIPANTS: 10 women, eight primiparous and two multiparous, who were interviewed two to five days post delivery. KEY FINDINGS: The essential meaning of women's experiences of complicated childbirth is the desire to be recognised and affirmed as a genuine subject. If this happens they feel accepted as childbearing women and as mothers-to-be, even if obstetric interventions are necessary and high technology is used. IMPLICATIONS FOR PRACTICE: By understanding and respecting every women as an individual the caregivers support women giving birth and make them feel accepted, thus paving the way for them to gain control over the situation. Through a true dialogue resulting in a trustful relationship, the women can manage even emergency situations. Separation of the mother and her baby should be avoided if possible.

Adolescent↗
PubMed1998

An introduction to anesthesia-related medications.

Many articles written about anesthesia and anesthetic agents can be rather in-depth and somewhat dry (i.e., boring). This article is an attempt to avoid some of those pitfalls. This article is based almost entirely on the opinions of a CRNA with 14 years experience. It is intended as a brief overview. It is not my intention to write a comprehensive, technical description of anesthesia, because this has been done multiple times much better than I could. Hopefully, this will give a description of the types of drugs commonly used in anesthesia. At the conclusion of this article is a brief example of the "context" in which these drugs are used.

Adjuvants, Anesthesia↗
PubMed1998

Patients with visual display unit-related facial symptoms are stingers.

Thirty patients without obvious skin disease but with subjective skin symptoms related to work with visual display units (VDUs) and 32 healthy persons were single-blind-tested with a solution of 5% lactic acid and pure water on their cheeks. Thirteen of the patients and 6 control persons reacted positively as "stingers" (p < 0.05) in this objective test of sensitive skin. The reason why some patients react with subjective symptoms like itching, burning, stinging, prickling or tingling is unclear. The result of this study, that patients with VDU-related skin symptoms have sensitive skin, does not tell anything about the aetiology of the symptoms. Former studies speak against the role of electric and magnetic fields and indicate that "techno-stress", cognitive factors or flickering from the VDUs or fluorescent tubes could be of importance, as could the Swedish mass media debate.

Adult↗
PubMed1998

Characteristics of users and nonusers of alternative medicine in dermatologic patients attending a university hospital clinic: a short report.

OBJECTIVES: To study the characteristics of users of alternative medicine in dermatologic outpatients attending a university clinic. DESIGN: A cross-sectional study analyzed by using a case-control methodology. SETTING, SUBJECTS, AND STUDY MEASURES: 118 dermatologic patients attending an outpatient university clinic responded to a structured questionnaire concerning demographic data, medical history, experience with alternative medicine, health beliefs, lifestyle, and locus of control. RESULTS: Thirty-five percent of the patients reported having used some form of alternative medicine. Use was related to disease duration, but not to patients' beliefs regarding whether or not they could influence their own health, nor to dissatisfaction with orthodox medicine. The most common reason for trying alternative medicine was that they "wanted to try everything" in an attempt to cure the skin disease. Users stated to a greater extent than nonusers, that they exercised sufficiently, possibly indicating that they are more health conscious. CONCLUSIONS: The study suggests that dermatologic patients using alternative medicine in general do not differ with regard to personal characteristics from nonusers. Rather, it appears that patients with long-standing skin disease turn to alternative medicine as a complement to orthodox treatment.

Case-Control Studies↗
PubMed1998

Two domains of the Borna disease virus p40 protein are required for interaction with the p23 protein.

Borna disease virus (BDV) has five major open reading frames, which encode the proteins p40, p23, gp18, p57 and p190. By analogy with other negative-strand RNA viruses, p40 is a putative nucleoprotein and p23 is a putative phosphoprotein. These proteins are known to form complexes with each other and with the polymerase protein in other viruses. In this paper, it is shown that BDV p40 and p23 can form complexes with each other in infected cells. Furthermore, the amino acids of p40 that are necessary for formation of this complex have been mapped.

Amino Acid Sequence↗
PubMed1998

Atrial lead implantation during atrial flutter or fibrillation?

In patients with sinoatrial disease, unexpected atrial flutter (Af) or fibrillation (AF) is a common problem during implantation of atrial-based pacing systems. As an alternative approach to blind atrial lead placement, lead positioning could be optimized by atrial electrogram mapping. It was the object of this study to evaluate if atrial lead implantation according to this approach and during ongoing arrhythmia is reasonable or if it should be postponed until restoration of sinus rhythm (SR). Twenty-nine consecutive patients (group I) with sick sinus syndrome received a dual-chamber pacemaker during an episode of Af (n = 11) or AF (n = 18). All but two atrial leads were of the screw-in type and had bipolar sensing. Atrial lead position was optimized by mapping the electrogram under fluoroscopy to find locations with high potential amplitudes. The patients were followed for 15.1 +/- 9.8 months, and atrial sensing threshold (AST), atrial pulse width threshold (PWT) at 2.0 V, the pacing mode programmed, and the clinical outcome (OUT) were recorded. The control group consisted of 30 patients (group II) who equally had a history of AF or Af, but were in SR during implantation. The atrial peak-to-peak potential (APEAK) after final lead placement was lower for AF (median value 2.5 mV, lower-upper quartile: 1.7-3.1 mV) as compared to Af (3.8 mV, 2.7-4.9 mV, P < 0.05) and SR (4.1 mV, 3.3-6.2 mV, P < 0.001). There was a correlation (P < 0.01) between APEAK during Af/AF and the postoperative AST immediately after restoration of SR. No lead in any group had to be corrected due to improper sensing in the postoperative course. Median chronic AST was 2.8 mV (2.0-4.0 mV) in group I and 4.0 mV (2.8-4.0 mV) in group II. Median chronic PWT at 2.0 V was 0.15 ms (0.12-0.26 ms) in group I and 0.15 ms (0.09-0.20 ms) in group II. There was no significant difference in chronic AST and PWT between both groups. All but two patients in group I preserved SR as the basic rhythm. A stable SR was observed in 10 of 29 patients, intermittent Af/AF was documented in 17 of 29 patients, seven of whom were asymptomatic. There was no significant difference in OUT between group I and II. Hence, sinus rhythm is not a prerequisite of atrial lead implantation. Mapping the Af or AF waves appears to be useful to guide lead placement and to achieve sufficient sensing and pacing conditions after conversion to sinus rhythm.

Aged↗
PubMed1998

Telemetry guided pacemaker programming: impact of output amplitude and the use of low threshold leads on projected pacemaker longevity.

In a prospective study, a low threshold screw-in electrode (Medtronic 5078, group I, n = 9) was compared to a conventional active fixation lead (Biotronik Y60BP, group II, n = 9) to investigate whether lower pacing thresholds really translate into longer projected service life of the pacemaker. The leads were implanted in the atrium and were connected to a dual chamber pacing system which included the same ventricular lead (Medtronic 5024) and the same pulse generator model (Intermedics 294-03) in both groups. Eighteen months after implantation, atrial and ventricular pacing thresholds were measured as the charge delivered per pulse [microC] at 0.5, 1.0, 1.5, 2.0, and 3.5 V, respectively. For chronic output programming in both channels, patients capturing at 0.5 V were set to 1.0 V, those capturing at 1.5 V were permanently programmed to 2.0 V with the double of the charge threshold as the safety margin for pacing ("safety charge"). A combination of atrial and ventricular output settings was optimal, if it resulted in minimum battery current drain (microA] as measured by pacemaker telemetry. In both groups, current consumption [microA] decreased significantly as output amplitude was decreased, exhibiting its lowest value at 1.0 V in either channel. All ventricular leads could be programmed to the optimum output amplitude of 1.0 V in groups 1 and 2. As the 2:1 "safety charge" values were almost identical, the ventricular channel essential contributes the same amount to the battery drain of the pacing system in both groups. In the atrium, all patients of group 1 could be programmed to the optimum output amplitude of 1.0 V with an average pulse duration of 0.42 +/- 0.15 ms. In group 2, however, all patients had to be programmed to 2.0 V with a mean pulse width of 0.52 +/- 0.15 ms. With the atrial and ventricular output being optimized, the average battery drain of the whole pacing system was 12.19 +/- 0.63 microA in group 1 versus 14.42 +/- 0.32 microA in group 2 (P < 0.001). As patients were chronically programmed to these output settings, this difference translates into a clinically relevant gain in projected pacemaker longevity of 17 months or 18.3% (121 +/- 4 vs. 104 +/- 2 months; P < 0.001). Thus, programming a 2:1 safety margin in terms of charge and optimizing the output parameters by real-time telemetry of the battery current is a useful approach to reduce battery current drain. Making the most of modern lead technology with a different performance in only one channel of an otherwise identical DDD pacing system translates into a significant prolongation of projected pacemaker service life which is of great importance with the increasing awareness of health care expenditures. The gain in projected longevity is mainly due to the option of reducing the output amplitude which is still significantly beneficial well below the nominal voltage of the power source.

Aged↗
PubMed1998

Identification of an Na+-dependent malonate transporter of Malonomonas rubra and its dependence on two separate genes.

Two membrane proteins encoded by the malonate fermentation gene cluster of Malonomonas rubra, MadL and MadM, have been synthesized in Escherichia coli. MadL and MadM were shown to function together as a malonate transport system, whereas each protein alone was unable to catalyze malonate transport. Malonate transport by MadLM is Na+ dependent, and imposition of a DeltapNa+ markedly enhanced the rate of malonate uptake. The kinetics of malonate uptake into E. coli BL21(DE3) cells synthesizing MadLM at different pH values indicated that Hmalonate- is the transported malonate species. The stimulation of malonate uptake by Na+ ions showed Michaelis-Menten kinetics, and a Km for Na+ of 1.2 mM was determined. These results suggest that MadLM is an electroneutral Na+/Hmalonate- symporter and that it is dependent on two separate genes.

Biological Transport↗
PubMed1998

Functional cooperation of the interleukin-2 receptor beta chain and Jak1 in phosphatidylinositol 3-kinase recruitment and phosphorylation.

Phosphatidylinositol 3-kinase (PI 3-K) plays an important role in signaling via a wide range of receptors such as those for antigen, growth factors, and a number of cytokines, including interleukin-2 (IL-2). PI 3-K has been implicated in both IL-2-induced proliferation and prevention of apoptosis. A number of potential mechanisms for the recruitment of PI 3-K to the IL-2 receptor have been proposed. We now have found that tyrosine residues in the IL-2 receptor beta chain (IL-2Rbeta) are unexpectedly not required for the recruitment of the p85 component of PI 3-K. Instead, we find that Jak1, which associates with membrane-proximal regions of the IL-2Rbeta cytoplasmic domain, is essential for efficient IL-2Rbeta-p85 interaction, although some IL-2Rbeta-p85 association can be seen in the absence of Jak1. We also found that Jak1 interacts with p85 in the absence of IL-2Rbeta and that IL-2Rbeta and Jak1 cooperate for the efficient recruitment and tyrosine phosphorylation of p85. This is the first report of a PI 3-K-Jak1 interaction, and it implicates Jak1 in an essential IL-2 signaling pathway distinct from the activation of STAT proteins.

Cell Line↗
PubMed1998

Human carotid arteries: correlation of intravascular US with angiographic and histopathologic findings.

PURPOSE: To establish the intravascular ultrasound (US) morphology of the arterial wall in various segments of the carotid artery and to evaluate atherosclerotic changes correlated with angiographic and in vitro histopathologic findings. MATERIALS AND METHODS: A total of 67 carotid arteries were imaged with a 3.5-F, 30-MHz intravascular US catheter: Twenty-four arteries were studied in vivo in 22 patients during neuroendovascular interventional procedures, in situ in 10 cadaveric arteries, and in vitro in 33 fresh excised arteries. RESULTS: In vivo, none of 10 calcifications and five (29%) of 17 intimal thickenings detected at intravascular US were seen at contrast material-enhanced angiography. At intravascular US, the arterial wall morphology was consistently three layered in the internal carotid artery above the bulb, either vaguely three layered or homogeneous in the bulb and in the carotid bifurcation, and homogeneous in the majority of common carotid arteries. The medial-adventitial interface was distinct in 21 (88%) of 24 arteries in vivo. Histopathologic and intravascular US classifications of the plaque agreed for 31 (82%) of the 38 arterial specimens in vitro. CONCLUSION: In vivo intravascular US was feasible in carotid arteries with mild atherosclerosis and often revealed intimal thickenings and concentric plaques in angiographically normal segments.

Adult↗
PubMed1998

Porcine rubulavirus LPMV RNA persists in the central nervous system of pigs after recovery from acute infection.

In order to study persistence of the porcine rubulavirus LPMV, we examined tissue samples collected from pigs 53 days after experimental infection. These pigs survived the initial infection and could clinically be considered to have recovered from the infection. Two of the pigs used in this study were chemically immunosuppressed during the last 4 days before necropsy. No infectious virus or viral antigen could be detected in any tissue using standard methods for virus isolation and detection. However, the presence of viral genomic RNA and mRNA could be demonstrated in the mid brain of the convalescent pig using an optimised RT-nested PCR. Mid brain, forebrain and lung were all shown to contain LPMV RNA in the immunosuppressed convalescent pigs. In addition we examined the P-gene editing in the recovered pigs and conclude that the viral genome is transcriptionally active in these pigs. The relevance of the persistence of LPMV for maintenance and spread within and/or between pig populations is discussed.

Acute Disease↗
PubMed1998

Medical work and the computer-based patient record: a sociological perspective.

The computer-based patient record (CPR) is a tool likely to have great impact on the practice of medicine in the years to come. Yet, clinical settings with a fully integrated CPR are hard to find. This paper takes a sociological look at the attempts to construe and introduce CPRs. It is argued that part of the current trouble in getting these tools to work lies in the model of medical work that is inscribed in many (attempted) CPRs. A more sociological perspective on medical work should be able to offer points of departure for the construction of systems which might fit the needs of health care workers better. Based on participatory observation, the paper outlines what it is medical work comes down to from a sociological perspective, and how the medical record figures in this work. Finally, some consequences this depiction has for current discussions on and (proposed) implementations of CPRs are described.

Data Collection↗
PubMed1997

Sequence of a gene cluster from Malonomonas rubra encoding components of the malonate decarboxylase Na+ pump and evidence for their function.

Malonate decarboxylation in Malonomonas rubra involves the formation of malonyl-S-[acyl-carrier protein] from acetyl-S-[acyl-carrier protein] and malonate, carboxyltransfer to a biotin protein and its decarboxylation that is coupled to delta mu Na+ generation. The genes encoding components of the malonate decarboxylase enzyme system have been cloned and sequenced. These are located within a gene cluster of approximately 11 kb comprising 14 genes that have been termed madYZGBAECDHKFLMN in the given order. Upstream of madY an open reading frame pointing into the opposite direction of the mad genes was found with structural similarities to insertion-sequence elements. The upstream region also contains DNA regions which are typical for an Escherichia coli sigma 70 promoter. Within 950 bp downstream of madN no other open reading frame was found. This region contains a putative terminator sequence. The intergenic regions within the mad gene cluster are short (usually < 70 bp, maximum 302 bp) and ribosome binding sites were defined before all 14 genes. Thus, this DNA region could form a transcriptional unit and all 14 genes could be translated into proteins. The genes madABCDEF encode the structural proteins of the malonate decarboxylase as yet identified. By comparing protein and DNA sequences and by data bank searches for related proteins with known function the following assignments could be made: MadA represents the acyl-carrier-protein-transferase component. MadB is the integral membrane-bound carboxybiotin protein decarboxylase, MadC and MadD are the two subunits of the carboxyltransferase, MadE is the acyl carrier protein and MadF is the biotin protein. Sequence comparison further indicates that MadH could be involved in the acetylation of the phosphoribosyl-dephospho-CoA prosthetic group and MadG could be involved in its biosynthesis. MadL and MadM are membrane proteins that could function as malonate carrier. The function of the madY,Z,K and N gene products is as yet unknown.

Amino Acid Sequence↗
PubMed1997

Fc gamma receptor II dependency of enhanced presentation of major histocompatibility complex class II peptides by a B cell lymphoma.

Here we show that the B cell lymphoma A20.292 is capable of enhanced antigen presentation to CD4+ T cells in the presence of specific antibodies. This enhancement was inhibited by anti-Fc gamma receptor (R) antibodies, suggesting that it might be due to preferential uptake of the antigen/antibody complex through the Fc gamma RII receptor. However, immunoprecipitation studies revealed that the FcR of A20.292 cells was of the B cell type, Fc gamma RIIb1, which is not thought to be able to internalize antigen/antibody complexes via clathrin-coated pits. It was considered unlikely that A20.292 had an altered form of the B cell Fc gamma R (RIIb1) receptor that enabled internalization, since similar enhancing effects were also observed using an Fc gamma RII cell line that had been transfected with Fc gamma RIIb1. To reconcile these findings with the expression of Fc gamma RIIb1, it is postulated that immune complexes are concentrated on the cell surface by the Fc gamma RIIb1 and are thus available for preferential uptake by random fluid-phase endocytosis. This results in more efficient generation of the epitopes recognized by these T cell hybridomas.

Animals↗
PubMed1997

Analysis of the large (L) protein gene of the porcine rubulavirus LPMV: identification of possible functional domains.

The complete nucleotide sequence of the porcine rubulavirus LPMV (La Piedad Michoacan virus) large (L) protein gene was determined and analysed. The L mRNA was found to span 6,786 nucleotides, containing one single large open reading frame (ORF), putatively encoding a polypeptide of 2,251 amino acids. By aligning the amino acid sequence of the LPMV L-protein with L-protein of a number of viruses belonging to the order mononegavirale, a high degree of similarity between the LPMV L-protein and other rubula virus L-proteins was demonstrated, extending through almost the whole protein. Additionally we could identify several regions as being highly conserved among all studied viruses of the order mononegavirale. The significance of these regions are discussed.

Amino Acid Sequence↗
PubMed1997

Problems and promises of the protocol.

Creating protocols (or guidelines, standards) for medical work is becoming big business. The pros and cons of protocols have been reiterated many times: advocates argue that protocols may enhance the quality of care, reduce unwanted variations in practice, and may help to render medical practice more scientific. Critics, on the contrary, argue that protocols will lead to cookbook medicine, to de-skilling, and to a reduced quality of care. In the continuing reiteration of these claims, they have more and more become removed from the actual practices of medical work and of the creation and use of protocols. Building on empirical research of these practices, this paper attempts to revitalise the debate. Four problems of the protocol are discussed: the protocol reinforces the tendency to perceive and describe medical action as an individual, formally rational process; the protocol contributes to the widespread illusion of the single answer; the protocol contributes to the loss of importance of information and interventions which are difficult to explicate and/or to quantify; and the protocol will lead to an increasing bureaucratisation and regulation of health care practices. Judicious use of protocols has several promises, which are discussed subsequently: explicating a scheme of actions creates a forum for discussion, and delegating parts of the decision-making process to a protocol may lead to personnel acquiring new competences.

Clinical Competence↗
PubMed1997

Analysis of the fusion protein gene of the porcine rubulavirus LPMV: comparative analysis of paramyxovirus F proteins.

Complementary DNA clones representing the fusion (F) protein gene of the porcine rubulavirus LPMV were isolated and sequenced. The F gene was found to be 1,845 nucleotides long containing one long open reading frame capable of encoding a protein of 541 amino acids. The cleavage motif for F0 into F1 and F2 is His-Arg-Lys-Lys-Arg. A sequence comparison and a phylogenetic analysis was performed in order to identify possible functional domains of paramyxovirus fusion proteins and also to classify the porcine rubulavirus. The F gene of LPMV is most closely related to the human mumps virus and simian virus type 5 F genes, and is therefore classified into the rubulavirus genus. A coding region for a small hydrophobic protein was however not found between the F and hemagglutinin-neuraminidase (HN) genes as previously found in both SV5 and mumps.

Amino Acid Sequence↗