Specimen banking--a planning in advance

The future value and usefulness of a Specimen Banking Programme is dependent on the way we select the material to be saved and the way we save it. If the material consists of non-representative samples or samples from which we cannot produce a set of analytical chemical data that allows us to make a proper statistical analysis, then the data merely provides us with anecdotal information. Experience as well as studies of large data sets have taught us that poor research material gives us poor understanding and knowledge. We know in advance that some questions will be important in the future. Of these, spatial and temporal changes in environmental contamination are high on the list. What priorities should we set and what kind of selection criteria should we use to create useful collections in the specimen banks? This paper will discuss some of the qualities samples must possess if they are to be included in a specimen bank.

The Swedish Environmental Specimen Bank--application in trend monitoring of mercury and some organohalogenated compounds

The Environmental Specimen Bank (ESB) at the Swedish Museum of Natural History, Stockholm, constitutes a base for ecotoxicological research as well as for spatial and trend monitoring of contaminants in Swedish fauna. Since the 1960s, tissue samples from more than 150000 organisms have been collected from different groups of animals, habitats and types of landscape. Samples from the ESB have been utilized for retrospective studies of trace elements, organohalogenated compounds and radionuclides. Among many matrices utilized, eggs of guillemot (Uria aalge) have proven to be an appropriate matrix for assessment of the contamination of the Baltic Sea. Results from time trend studies based on this material showing trends in concentrations of DDT, PCB, PCDD/F, and mercury are presented in this paper.

No evidence of nosocomial Pneumocystis carinii infection via health care personnel

Clusters of Pneumocystis carinii pneumonia (PCP) in immunocompromised settings suggest person-to-person transmission. We examined whether personnel in a ward for HIV-infected patients were carriers of P. carinii. None of 29 sputum samples from 19 personnel caring for HIV-infected patients had detectable amounts of P. carinii DNA, as determined by the two PCR methods used. Two of 26 personnel were found, by an immunofluorescence assay, to have serum antibodies for P. carinii. The results do not support the hypothesis that personnel represent major vectors or transient reservoirs for spreading P. carinii infection to immunocompromised hosts.

Social support in bereavement crisis--a study of interaction in crisis situations

This article is based on a study of the interaction between relatives of patients who died in Coronary Care Units in Sweden and staff members of these units. The social support concept is used in a qualitative analysis of the narratives of bereaved spouses and adult children in order to learn about the nature of supportive interactions in such crisis situations. Specific needs for support and different patterns in mobilizing support are described as well as obstacles to the supportive process stemming from the nature of the crisis situation and problems in the interaction. The findings indicate reciprocal influences between the individual bereavement process and the interpersonal social support process. The author also suggests ways for medical social workers to use the findings.

Thoracoscopic parathyroidectomy of an ectopic mediastinal adenoma

Thoracoscopic parathyroidectomy in a patient with an adenoma in the lower mediastinum is described. This is a new method, probably reducing morbidity compared with median sternotomy, and has to the authors' knowledge not been described before.

Influence of dolichol on microsomal membrane functions

Microsomal membranes from rat liver were extracted with n-pentane in order to remove the lipid products of the mevalonate pathway, dolichol, ubiquinone and cholesterol. Dolichol and cholesterol were subsequently reincorporated into these extracted membranes. Electron microscopic examination demonstrated that extraction did not alter the vesicular membrane structure of the microsomes. The extracted vesicles were permeable to uncharged molecules in the same manner as control microsomes but had an increased permeability for charged molecules. Enzyme denaturation was not observed. The contraction of extracted vesicles was greatly increased when the incubation medium was supplemented with non-penetrating compounds such as polyethylene glycol and was much greater than that of control microsomes. When extracted membranes were reconstituted with dolichol or cholesterol, the original lower degree of contraction was reestablished. The effects of dolichol reincorporation on a number of microsomal enzyme activities were investigated and some limited changes were observed. These results demonstrate that extraction of microsomes with n-pentane and subsequent reincorporation of dolichol is an effective approach for investigating the functions of this lipid. Dolichol and cholesterol both affect microsomal membrane fluidity, but only cholesterol modifies the activities of certain integral microsomal membrane enzymes to a larger extent.

Quality of life in octogenarians after valve replacement due to aortic stenosis. A prospective comparison with younger patients

BACKGROUND

Results of aortic valve surgery in octogenarians have been evaluated as event-free survival. However, little attention has been given to quality of life aspects.

METHODS

Thirty-two consecutive patients, mean age 83 +/- 2 years, undergoing valve replacement due to aortic stenosis, were compared to 30 patients, mean age 71 +/- 3 years, undergoing the same procedure. Mortality, morbidity and quality of life were studied. An interview was performed before surgery and 3 and 12 months postoperatively. The questionnaire contained items related to self-rated health, symptoms, physical ability, sleep disturbances and social and emotional functioning.

RESULTS

Pre-operatively the older patient group was in a worse condition with a higher NYHA functional class and a more pronounced cardiomegaly. They had more cardiac symptoms and were more depressed. The control group had a higher score for physical ability and rated their quality of life as better. Postoperatively there was a higher early mortality rate in the octogenarians (9% vs 0%; ns). After 3 months, improvement of functional status and relief of symptoms was observed in both groups. Physical ability improved and the depression score decreased significantly in both groups. Self-rated health and quality of life improved. One year after valve replacement the improvement in quality of life was of a similar magnitude in the two groups.

CONCLUSION

Following aortic valve replacement, octogenarians, despite a more compromised pre-operative status showed an improvement in symptomatology, physical ability and general well being, of a similar magnitude to that of the younger patients group. These findings lend further support to the recommendation that valve replacement should be performed in octogenarians with symptomatic aortic stenosis.

A rapid and simple nested PCR assay for the detection of Pneumocystis carinii in sputum samples

Detection of Pneumocystis carinii by the polymerase chain reaction (PCR), based on the thymidylate synthase (TS) gene of rat P. carinii, is a specific and sensitive method for the detection of the parasite in respiratory samples. However, the use of the method is limited by a laborious phenol-chloroform DNA extraction method and an expensive and time-consuming hybridization procedure. For routine clinical samples, DNA preparation can be simplified and hybridization substituted by a nested PCR technique. Such a modified PCR procedure, based on the TS gene of P. carinii, was evaluated on 190 induced sputum samples from 50 immunosuppressed patients, infected with human immunodeficiency virus (HIV), with and without symptoms of P. carinii pneumonia (PCP). The PCR assay, preceded by a rapid DNA preparation (Wizard DNA Clean-up), detected P. carinii-DNA in 13/15 sputa containing parasites as seen by microscopy using immunocytochemical (IFL) staining, and in 10 additional sputum samples lacking demonstrable parasites by microscopy. These samples are to be considered as 'true' positives, since all but 2 were from patients, who developed a PCP within 1 year. We conclude that the nested PCR assay is more sensitive than IFL for the detection of P. carinii in AIDS patients, prior to the debut of PCP symptoms.

Detection of Pneumocystis carinii DNA by filtration of air

The high incidence of pneumonia caused by Pneumocystis carinii in immunosuppressed patients makes it the most important parasite in non-tropical geographical regions. It has recently been shown to be a fungus, but several aspects of this organism are still poorly understood. A major question of clinical relevance is the nature of transmission and, thereby, the related problem of prevention. The mode of P. carinii transmission is thought to be air, but this is based on circumstantial evidence, the transmissive stage has not been identified. We attempted to capture P. carinii by filtration of air in the vicinity of cages containing P. carinii infected Wistar rats. Using nested polymerase chain reaction amplification of the thymidylate synthase gene to demonstrate P. carinii we were able to demonstrate P. carinii DNA on such filters. This strongly supports the suggested mechanism of transmission of Pneumocystis by means of airborne spores and suggests an approach to their isolation and characterization.

Projection neurons in fetal striatal transplants are predominantly derived from the lateral ganglionic eminence

In the present study, we have characterized aspects of integration, growth and phenotypic differentiation of embryonic grafts derived from the selective dissection of either the lateral or medial portion of the ganglionic eminences of the rodent forebrain. Donor tissues were derived from embryonic day 15 rat, or embryonic day 14 mouse embryos, and injected, as single cell suspensions into the striatum or substantia nigra of adult rats previously subjected to an intrastriatal ibotenic acid lesion. Two to six weeks following grafting, immunocytochemical detection of DARPP-32, the 32,000 mol. wt dopamine- and cyclic AMP-regulated phosphoprotein, was used to identify areas with a striatum-like phenotype within both the intrastriatal and the intranigral grafts. It was thus revealed that all the lateral ganglionic eminence grafts, irrespective of their placement, were dominated by striatum-like tissue (up to 90% of the total graft volume), while the medial ganglionic eminence transplants were only sparsely positive (< 10% of the total graft volume). These striatum-like regions of the grafts were selectively innervated by tyrosine hydroxylase immunopositive fibres from the host substantia nigra. Furthermore, axons derived from the lateral ganglionic eminence mouse grafts placed in the striatum, as detected by the mouse-specific neuronal marker M6, showed a more extensive and directed outgrowth towards the globus pallidus when compared to fibres emanating from the medial ganglionic eminence grafts. Mouse lateral and medial ganglionic eminence grafts placed into the substantia nigra exhibited similar fibre outgrowth patterns; both types of grafts thus innervated the substantia nigra-pars reticulata and extended axons into the cerebral peduncle. These results show that DARPP-32-positive striatal projection neurons are derived, for the most part, from the lateral ganglionic eminence and that the restricted lateral ganglionic eminence dissection provides a more optimal source of striatal tissue for grafting in the rat Huntington model.

Regional incorporation and site-specific differentiation of striatal precursors transplanted to the embryonic forebrain ventricle

The developmental potential of neural progenitors derived from the E13.5-E14 lateral or medial ganglionic eminences (LGE and MGE, respectively) or the E12 ventral mesencephalon (VM) was examined in cross-species transplantation model. After injection into the E15 rat forebrain ventricle, mouse LGE progenitors (unlike those of the MGE or VM) were consistently integrated into the host striatum, expressing neurochemical phenotypes and axonal projections characteristic of striatal projection neurons. Additionally, both LGE and MGE precursors displayed widespread incorporation into distinct forebrain and midbrain structures, whereas the more caudally derived VM cells were largely confined to midbrain structures. These results suggest that many LGE precursors are positionally specified for striatal incorporation, while a portion also possess greater potential reflected in more widespread integration following intraventricular injection.

Preservation of fetal ventral mesencephalic cells by cool storage: in-vitro viability and TH-positive neuron survival after microtransplantation to the striatum

Preservation of fetal ventral mesencephalic (VM) dopaminergic tissue prior to transplantation has been hampered by the fact that the cells are vulnerable to mechanical and osmotic stress after storage. Previous quantitative studies have shown that cool storage in a so-called 'hibernation medium' prior to grafting, can be used safely for up to 2 days without morphological or functional losses [16,32] using standard transplantation techniques. In the present study on rat fetal VM tissue we have investigated (i) the accuracy of different vital stains (trypan blue exclusion and ethidium bromide stain) to predict in vivo viability of VM cell suspensions after grafting; (ii) the influence of different storage media (glucose-saline, HBSS, DMEM, CO2-independent medium and hibernation medium), temperatures (+4 degrees C or +21 degrees C) and preparations (cell suspension or intact pieces) on the viability scores and total number of cells in vitro; and (iii) the survival and functional effects of intrastriatally grafted VM tissue after preservation by cool storage for up to 12 days using a less traumatic microtransplantation technique. The results show that cool storage at +4 degrees C of intact VM pieces in hibernation medium gives the best in vitro viability scores. Microtransplantation of cell suspensions prepared from cool-stored VM tissue produced good survival of tyrosine hydroxylase (TH)-positive graft neurons for up to 8 days of storage, and functional compensation in the amphetamine-rotation test for up to 12 days of storage. The total yield of surviving TH-positive neurons was unchanged, compared to fresh grafts, after 5 and 8 days of storage, and only reduced by 48% in the grafts stored for 12 days prior to implantation. These findings highlight the potential usefulness of a combination of cool storage and microtransplantation techniques to be able to extend the preservation periods of VM tissue. Such procedures may ultimately help to increase the safety and flexibility in experimental and clinical studies on neural transplantation of dopaminergic neurons.

The GTPase activity of the Escherichia coli Ffh protein is important for normal growth

The Escherichia coli (E. coli) Ffh protein is homologous to the 54kDa subunit of the eukaryotic signal recognition particle. We have examined an intrinsic GTPase activity of this protein and have created mutations in one sequence motif (GXXXXGK) of the putative GTP binding site. When glycine-112 was changed to valine (Ffh-G112V), Vmax was reduced to only 4% of the wildtype level. On the other hand, when glutamine-109 was altered to glycine (Ffh-Q109G), the major effect was a 50-fold increase in Km. These results show that the residues Q-109 and G-112 are essential for the binding and hydrolysis of GTP and that they are part of a catalytic site structurally related to that of many other GTPase proteins. Expression of the mutant protein Ffh-G112V in E. coli was highly toxic in the presence of the wildtype protein. In contrast, genetic complementation experiments showed that a viable strain could be constructed where the Ffh-Q109G mutant protein replaced wildtype Ffh. However, expression of the mutant protein had a negative effect on growth rate at 30 degrees C and resulted in elongated cells. These results demonstrate that the GTPase activity of the Ffh protein is required for proper function of the protein in vivo.

Bridges supported by free-standing implants versus bridges supported by tooth and implant. A five-year prospective study

The clinical question at issue, whether it is possible to combine implants and natural teeth via fixed bridges, is of current interest. The treatment of the subjects of this prospective study was performed between June 1984 and December 1986. This article presents the 5-year results of the study. The consecutive patient material comprised 23 patients with Applegate Kennedy Class I residual dentition in the mandible and a complete maxillary denture. All 23 patients were provided with implants ad modum Brånemark in each mandibular quadrant. One side was randomized to rehabilitation with fixed bridge between the distal tooth of the residual dentition and an implant; the other side received a free-standang bridge on 2 implants. The fixture survival rate was 88%. No difference was found between the two sides. Bridge stability was 89% for the implant bridges and 91% for the combination bridges. The change in marginal bone level at the implants was small during the 5-year follow up period (on average 0.1-0.3 mm) and with no difference between the two sides. In conclusion, it was not possible to demonstrate any higher risk of implant or prosthetic failure for tooth-implant fixed bridges compared with implant-supported bridges.

Mandibular function before and after orthodontic treatment

To determine the influence of orthodontic treatment on mandibular function, a longitudinal study was initiated on 245 consecutive prospective orthodontic patients before and after the orthodontic treatment. Of the 245 referred patients, eight declined treatment and 27 moved to other parts of the country before the treatment was completed. Thus, the longitudinal study was based on 210 patients. The functional examination was made according to Carlsson and Helkimo (1972) and Helkimo (1974), and by the same person (MO). Before the orthodontic treatment, symptoms of temporomandibular disorders (TMD) were found in 16.7 per cent of the patients and in 6.7 per cent after treatment. The number of subjects without signs or symptoms of TMD increased from 26.7 per cent before treatment to 46.2 per cent after. According to the dysfunction index (Helkimo, 1974), 31.4 per cent of the patients had a moderate and 13.8 per cent a severe mandibular dysfunction before the start of orthodontic treatment. After the treatment, the corresponding figures were 14.3 and 5.7 per cent, respectively. The material was divided into groups, consisting of boys and girls younger than 13 years, and 13 years and older at the start of treatment. Before treatment there was a higher prevalence of signs and symptoms of TMD in the older age group than in the younger, and higher in girls than in boys. After the orthodontic treatment, the prevalence was still higher in girls than in boys in both age groups, but not higher in the older age group than in the younger group.

Forelimb akinesia in the rat Parkinson model: differential effects of dopamine agonists and nigral transplants as assessed by a new stepping test

Methods for the assessment of akinesia in the unilateral rat Parkinson model have so far been lacking. The experiments reported here evaluate the usefulness of a new "stepping test" to monitor forelimb akinesia in rats with unilateral 6-hydroxydopamine (6-OHDA) lesions of the mesencephalic dopamine (DA) system, and to assess the ability of DA-receptor agonists and fetal DA neuron transplants to reverse these deficits. The 6-OHDA lesion induced marked and long-lasting impairments in the initiation of stepping movements with the contralateral paw. Systemic injections of low doses (chosen to be subthreshold for induction of rotation) of the mixed D1 and D2 receptor agonist apomorphine, the D1-selective agonist SKF 38393, and to a lesser extent also the D2-selective agonist quinpirole were effective in reversing these deficits. Similar effects was seen after a subrotational dose of L-dopa, whereas amphetamine had no effect. Fetal nigral transplants, implanted as multiple deposits in the ipsilateral caudate-putamen and substantia nigra, restored initiation of stepping to a similar degree as the DA agonists. Nigral grafts placed in substantia nigra alone were also effective, although the improvement was less pronounced. Apomorphine, at a dose effective in the lesion-only animals, had no additive effect in the grafted rats, whereas amphetamine appeared to further improve stepping in the rats with intranigral transplants. Identical experiments were performed on skilled forelimb use in the so-called staircase test. Interestingly, neither the DA agonist drugs nor the nigral transplants had any effects on the lesion induced deficits in this more complex task. The results show that forelimb stepping is a highly useful test to monitor lesion-/and transplant-induced changes in forelimb akinesia, a behavioral parameter that may be analogous to limb akinesia and gait problems seen in patients with Parkinson's disease.

MkII--a modified self-tapping Brånemark implant: 3-year results of a controlled prospective pilot study

A modified self-tapping implant (MkII) with improved cutting characteristics has been designed for use in both maxillae and mandibles. Four sequential studies were conducted to evaluate the outcome of the MkII implant compared to the standard implant. The results presented here are from the extended pilot study that has been conducted as an intra-individual study of 103 patients; ie, each patient received both test (MkII) and control (standard Brånemark System) implants. Seventy patients were treated in the mandible and 33 in the maxilla. The cumulative survival rates and marginal bone resorption showed equivalent results for both test and control implants. Three-year cumulative survival rates were 87.9% and 86.8% for test and control implants in maxilla, respectively, and 99.5% and 100% in mandibles, respectively. The mean marginal bone resorption was approximately 0.5 (control) to (MK II) 0.6 mm after 3 years of function. A total of 288 test implants and 275 control implants were placed. All implants, both test and control, could be placed in an appropriate implant position, but 21.2% of the implants were not fully seated by machine power only; the use of a manual cylinder wrench for the final turns was necessary. During the last phase of the study, however, with an increase in twist-drill diameter from 3.0 to 3.15 mm and an increased motor torque, the prerequisites of successful implant placement into final position were met.

Expression of HLA-DR antigen and smooth muscle cell differentiation markers by valvular fibroblasts in degenerative aortic stenosis

OBJECTIVES

This study was designed to analyze the functional characteristics of fibroblasts present in aortic valves with degenerative stenosis.

BACKGROUND

Morphologic analysis of degenerative stenosis of tricuspid aortic valves has revealed an extensive interstitial fibrosis.

METHODS

Stenotic aortic valves collected during aortic valve replacement and control valves collected at autopsy were fixed in formaldehyde, cryosectioned and stained with antibodies against leukocyte markers, HLA-DR and intracellular filaments. Fibroblasts isolated from stenotic valve and skin explants were grown in cell culture, and their proliferative activity was analyzed by cell counting and uptake of tritiated thymidine.

RESULTS

In the stenotic valves nearly all interstitial cells expressed vimentin, and approximately 60% of the cells also expressed alpha-actin and desmin. HLA-DR was present on inflammatory cells as well as on one-third of the fibroblast-like cells in the interstitium. Macrophages were found in the interstitium and T lymphocytes close to calcium deposits and in subendothelial areas. In control valves, fibroblasts expressed vimentin but not alpha-actin or desmin. Few inflammatory cells were present in these valves, and HLA-DR expression was restricted to the endothelial surface. In culture, stenotic valve fibroblasts had a reduced ability to proliferate in serum and to activate DNA synthesis in response to growth factors compared with skin fibroblasts from the same patient.

CONCLUSIONS

The observation that fibroblasts present in aortic valves with degenerative stenosis express smooth muscle cell characteristics and HLA-DR antigen and show signs of cellular senescence in vitro suggests that they are in a state of chronic activation similar to that observed in fibromatosis and scleroderma lesions.