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Biomedical subjects

K Nyberg

Publications and source records attributed to K Nyberg.

At least 19 recordsLinked to original sources
PubMed2000

Change of bone tissue composition and impaired bone strength in rats exposed to 3,3',4,4',5-pentachlorobiphenyl (PCB126).

The aim of this study was to compare effects of estrogen depletion (ovariectomy) and exposure to 3,3',4,4',5-pentachlorobiphenyl (PCB126) on bone strength and bone tissue composition in the rat. Half of the rats were ovariectomized (n=20) and the remainder were sham-operated. Ten of the ovariectomized rats and ten of the sham operated were exposed to PCB126 (ip injections) for 3 months (total dose, 384 microgram/kg bodyweight), while those remaining received the vehicle. The humerus and femur were used for analysis of torsional strength and biochemical studies, respectively. Both sham-operated and ovariectomized animals showed a significantly shorter bone length, lower water content and a decreased torsional stiffness when exposed to PCB126. Sham-operated rats exposed to PCB126 had lower maximum torque when compared with sham operated controls. The PCB126-exposed rats also exhibited a significantly lower collagen concentration, but showed a higher pyridinoline concentration of cortical bone. PCB126 exposure decreased the hepatic level of vitamin A but increased vitamin A levels in serum and kidneys. Ovariectomy per se increased bone length and organic content and decreased the inorganic content significantly, but did not affect any of the tested biomechanical parameters. In conclusion, this study showed that the common environmental pollutant PCB126 impaired bone strength and altered bone composition. It is hypothesized that these effects might partly be explained by PCB-induced retinoid disturbances.

Animals↗
PubMed2000

Perinatal medication as a potential risk factor for adult drug abuse in a North American cohort.

The aim of this study was to explore perinatal exposures to medications as risk factors for adult drug abuse. We compared 69 drug abusing subjects and their 33 non-abusing siblings with regard to history of labor pain analgesia during birth and other obstetric variables. Three or more doses of opiates or barbiturates at birth yielded an OR of 4.7 (95% CI = 1.0-44.1) for becoming a drug abuser after multiple perinatal drug exposure.

Adult↗
PubMed2000

Anal sphincter tears: prospective study of obstetric risk factors.

OBJECTIVE: To evaluate intrapartum risk factors for anal sphincter tear. DESIGN: A prospective observational study. SETTING: Delivery unit at the University Hospital in Göteborg, Sweden. PARTICIPANTS: 2883 consecutive women delivered vaginally during the period between 1995 and 1997. Information was obtained, from patient records and from especially designed protocols which were completed during and after childbirth. MAIN OUTCOME MEASURES: Anal sphincter (third and fourth degree) tear. RESULTS: Anal sphincter tear occurred in 95 of 2883 women (3.3%). Univariate analysis demonstrated that the risk of anal sphincter tear was increased by nulliparity, high infant weight, lack of manual perineal protection, deficient visualisation of perineum, severe perineal oedema, long duration of delivery and especially protracted second phase and bear down, use of oxytocin, episiotomy, vacuum extraction and epidural anaesthesia. After analysis with stepwise logistic regression, reported as odds ratio, 95% confidence interval, the following factors remained independently associated with anal sphincter tear: slight perineal oedema (0.40, 0.26-0.64); manual perineal protection (0.49, 0.28-0.86); short duration of bear down (0.47, 0.24-0.91); no visualisation of perineum (2.77, 1.36-5.63); parity (0.59, 0.40-0.89); and high infant weight (2.02, 1.30-3.16). Analysis of variance showed that manual perineal protection had a stronger influence on lowering the frequency, and lack of visualisation of perineum and infant weight had a stronger influence on raising the frequency, of anal sphincter tears in nulliparous compared with parous women. CONCLUSIONS: Perineal oedema, poor ocular surveillance of perineum, deficient perineal protection during delivery, protracted final phase of the second stage, parity and high infant weight all constitute independent risk factors for anal sphincter tear. Such information is essential in order to reduce perineal trauma during childbirth.

Adult↗
PubMed2000

Subcutaneous versus intracutaneous injections of sterile water for labour analgesia: a comparison of perceived pain during administration.

OBJECTIVE: To investigate whether, during injections of sterile water, there is any difference in perceived pain between intracutaneous and subcutaneous injections. DESIGN: Blind controlled trial with cross-over design. SETTING: Göteborg and Skövde, Sweden. PARTICIPANTS: One hundred healthy female volunteers. METHODS: The women were randomised into two groups and subjected to two trials, within one week of each other. During the first trial one group (n = 50) received the intracutaneous injection first, followed by the subcutaneous injection. The second group (n = 50) was given the subcutaneous injection first, followed by intracutaneous injection. In both groups all the injections were given in reverse order during the second trial. MAIN OUTCOME MEASURES: Experienced pain during the administration of sterile water injections, measured by visual analogue scale. RESULTS: The analysis showed intracutaneous injections to be significantly more painful than subcutaneous injections, even after adjusting for injection day and for left/right site of injection (mean 60.8 vs 41.3, P < 0.001). CONCLUSIONS: The findings suggest that the less painful subcutaneous injection technique should be used.

Adolescent↗
PubMed1997

How should midwives discuss smoking behaviour in pregnancy with women of low educational attainment?

OBJECTIVE: To understand how women with low educational attainment perceived the fact of their smoking during pregnancy in order to be able to construct suitable counselling programmes. DESIGN: Qualitative study using tape-recorded interviews. SETTING: Clinic north of Stockholm, Sweden. PARTICIPANTS: Thirteen women who had given birth during the previous months and who had smoked during pregnancy. FINDINGS: All of the women were aware that smoking presented risks to the fetus. Several had themselves experienced the damaging effects of smoking on the fetus. However, many talked about other women who had smoked and still given birth to healthy babies. Nevertheless, the majority felt guilty because they smoked, partly because it made them feel as though they were 'bad people' and partly out of concern for the baby. Most of the women stated that warnings and moralising from midwives did not make them cut down their smoking; on the contrary, many smoked more. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: None of the women had reached the stage where they felt motivated to stop smoking. Realistically speaking, probably only a few of them would be able to change their smoking habits during pregnancy. The interviews, however, showed the significance of a client/patient-centred methodology, based on the client's/patient's outlook and social situation. A potentially successful strategy could be to co-ordinate client/patient-centred methodology with cognitive behavioural programmes. An important task is also to confirm and strengthen these women in their roles as mothers-to-be and to introduce the subject of smoking in such a way that the women choose to reduce their smoking as much as possible, given the individual's own ability and social situation. These women might benefit from being confirmed in their maternal role despite the fact that they smoke. Group discussions, where they could 'think it over', would also be of significance, considering the influence of social norms.

Attitude to Health↗
PubMed1996

Isolation and mapping of three new polymorphic markers to chromosomes 3, 20 and 21.

Screening of single human chromosome plasmid libraries using a digoxygenin labelled (AAAT)15 oligonucleotide probe led to the identification of several positive clones. DNA sequence analysis of these was carried out and showed the presence of a number of simple DNA repeats. Oligonucleotide primers were designed from the sequences flanking these repeats and tested in PCR amplification reactions of human genomic DNA. Three of the markers tested were shown to be polymorphic with heterozygosities ranging from 40% to 69%. The markers were assigned to chromosomes using a panel of monochromosomal somatic cell hybrids combined with linkage analysis using DNA from the CEPH panel of families. The markers designated (AAAT)11, (AAAT)12 and (CA)19 were thus assigned to chromosomes 3, 21 and 20 respectively.

Base Sequence↗
PubMed1994

Phagolysosomal pH in alveolar macrophages from smokers and non-smokers.

1. Alveolar macrophages efficiently phagocytize particles deposited in the alveolar part of the lung. Phagolysosomal pH in alveolar macrophages from rabbits, dogs, baboons and guinea pigs is around 5 pH units. A low pH is of importance for clearance of inorganic particles and probably also for defence against bacteria and fungi. 2. Phagolysosomal pH in alveolar macrophages from smokers and non-smokers was measured using fluorescein-conjugated amorphous silica particles as a probe. pH was the same in both groups and similar to earlier studies on alveolar macrophages from animals. 3. The morphological picture between alveolar macrophages from smokers and non-smokers differed clearly with a high number of dense inclusions of great variation in size and shape in macrophages from smokers. Ingested test particles were located in all types of inclusions. 4. We conclude that phagolysosomal pH in human alveolar macrophages is similar to that in several animal species and that it is rather insensitive to influence from the environment.

Adult↗
PubMed1993

Obstetric medication versus residential area as perinatal risk factors for subsequent adult drug addiction in offspring.

In an attempt to explain pronounced uneven distributions of births of subsequent amphetamine and opiate addicts at seven hospitals in Stockholm, two possible mechanisms for adult drug addiction were weighed against each other: (1) risk factors associated with the obstetric care at the hospitals of birth of the addicts and (2) risk factors associated with the phenomenon of 'contagious' transmission of drug addiction in certain residential areas during adolescence. The subjects comprised 200 amphetamine addicts and 200 opiate addicts born between 1945 and 1966. By loglinear analysis the relative risk for future addiction was determined for eight residential areas as well as for the seven hospitals and four periods of birth. For the opiate addicts only one weak association was found for the residential area, which could not explain fully a clustering of births at any particular hospital. For the amphetamine addicts, hospital of birth was found to be an important risk factor even after controlling for residential area. Hence, the variable residential area has not been able to explain the uneven distribution of births of drug abusers among the studied hospitals.

Adult↗
PubMed1992

Socio-economic versus obstetric risk factors for drug addiction in offspring.

Two possible risk factors for drug addiction were weighed against each other: (1) perinatal factors associated with obstetric medication at time of birth; and (2) factors associated with familial socio-economic conditions at time of birth. The subjects comprised 200 amphetamine addicts and 200 opiate addicts born in Stockholm 1945-1966. In a matched case control study, addicts were compared to their siblings with regard to possible obstetric risk factors by means of conditional logistic regression controlling for socio-economic level and civil status. Administration of opiates, barbiturates and nitrous oxide to mothers during labour was associated with drug addiction in offspring, hence confirming results from earlier studies. In a cohort study the risk associated with birth at a given hospital and familial socio-economic level was analysed by means of log-linear analysis using 7100 controls from the general population. For amphetamine addicts, a low socio-economic level at time of birth might be of importance for the infant subsequently becoming an addict. This could not be demonstrated for the opiate addicts. An uneven distribution of births among the hospitals, most pronounced for the amphetamine addicts, is in agreement with the hypothesis that obstetric practices may be risk factors for adult drug addiction.

Adolescent↗
PubMed1992

Phagolysosomal pH in alveolar macrophages.

We studied phagolysosomal pH in alveolar macrophages (AM) using fluorescein-labeled yeast (FYP) and silica particles (FSP) as probes. Fluorescence intensities from the ingested test particles were measured on populations of AM using fluorescence spectrometry and on individual phagolysosomes using fluorescence microscopy. Measurements were performed on rabbit AM, which had been incubated with FYP or FSP (in vitro procedure). We also instilled FYP or FSP via the trachea into rabbit lungs and after 1 day, 1 week, 1 month, and 3 months lavaged the lungs and measured the pH in AM (in vivo procedure). Phagolysosomal pH was independent of the number and size of the fluorescent particles. Measurements of populations of AM with fluorescence spectrometry and of individual phagolysosomes with fluorescence microscopy gave similar average pH. For the FYP, pH decreased during the first day after lavage both in the in vitro and the in vivo procedures. For the FSP, pH was unchanged during the same period. After 1 day pH was similar for both particles. Electron microscopy showed a larger number of lysosomes in contact with phagosomes and a higher percentage of vacuolated phagosomes for FYP than for FSP. In the in vivo procedure, pH was unchanged at least up to 1 month, and this pH was lower than that in the in vitro procedure. The difference was probably due to conditions at the time of phagocytosis. Particles retained in the lung parenchyma were within AM, and their location within the AM appeared unchanged from 1 week up to 3 months.

Animals↗
PubMed1992

Pharmacological management of cancer pain. A guide for the health care professional.

Cancer pain continues to remain a significant problem for oncology patients treated in both the university and the community setting. Nursing knowledge regarding pain management has advanced significantly in recent years. This article provides health care professionals with current factual information on cancer pain management. The information focuses on the emotional aspects of cancer pain, specific principles of analgesic management, opioid equianalgesics, multiple approaches to opioid administration, management of unwanted side effects, and a description of inappropriate drug therapies.

Analgesia, Patient-Controlled↗