Extensive migration and target innervation by striatal precursors after grafting into the neonatal striatum

Embryonic striatal precursors grafted into the lesioned adult host striatum show limited integration with little migration and restricted efferent projections. In the present study, the influence of an immature striatal environment on the integrative capacity of grafted neuroblasts was examined after transplantation of striatal progenitors into the striatum at different stages of postnatal development. Mouse progenitors, derived from embryonic day 13.5-14 lateral or medial ganglionic eminence or the cerebellar primordium, were transplanted as a single cell suspension into the developing postnatal day 1, 7 and 21 rat striatum. The grafted cells and their axonal projections were visualized using antibodies raised against the mouse-specific neural markers, M6 and M2. Cells from the lateral (but not the medial) ganglionic eminence showed a remarkable capacity to innervate selectively the striatal target structures, globus pallidus, entopeduncular nucleus and substantia nigra, reminiscent of endogenous striatal neurons, which is not observed after grafting into adult hosts. M6 and M2-immunopositive cellular profiles from both the lateral and medial ganglionic eminences were observed to have migrated extensively away from the injection site, in contrast to the cerebellar precursors which remained clustered at the implantation site. Cells from the lateral ganglionic eminence were largely confined within the striatal complex where they developed striatal characteristics, displaying expression of DARPP-32, the 32,000 mol. wt dopamine- and cyclic AMP-regulated phosphoprotein, whereas cells from the medial ganglionic eminence had migrated caudally along the internal capsule and were observed predominantly in the globus pallidus and thalamus, in addition to the striatum. The cells located outside the striatum were all DARPP-32 negative. The improved integration and increased projection capacity of the lateral ganglionic eminence precursors grafted into postnatal day 1 hosts gradually declined as the host advanced into later stages of development (postnatal day 7), and in postnatal day 21 hosts the grafted striatal precursors behaved similarly to grafts implanted into adult recipients. These results demonstrate the specific capacity of embryonic striatal progenitors to integrate into the developing basal ganglia circuitry during early postnatal development, and that the extent of neuronal and glial integration and graft host connectivity declines when the host has developed beyond the first postnatal week.

Towards a molecular level understanding of protein stabilization: the interaction between lysozyme and sorbitol

The paper is investigating the mechanism of stabilization of proteins by polyols at the molecular level. It is addressing the interactions of sorbitol, a polyol commonly used as a protein stabilizing agent, with hen egg white lysozyme, a well studied protein. Differential scanning calorimetry shows an increase in denaturation temperature of lysozyme upon addition of sorbitol at a concentration of 250 mM and above. Increasing sorbitol concentration also caused an increase in signal intensity of the CD spectrum of lysozyme in the wavelength region of 280-300 nm. Two-dimensional nuclear magnetic resonance spectroscopy was used to examine interactions between lysozyme and sorbitol. Most significant changes are manifest in the anomalous relaxation properties of Ala and Thr methyl groups indicating modifications of local motions and possibly compression of the entire structure. This is further corroborated by new intra-protein nuclear Overhauser effects in the presence of sorbitol. There is also evidence that water is displaced from the enzyme surface close to Ile-88 upon addition of sorbitol. In combination these results reveal a complex interplay of different interactions. Comparison to NMR-spectra of lysozyme with a bound inhibitor (tri-N-acetyl-glucosamine) shows that the interaction with sorbitol affects spatially disparate regions of the protein.

Salivary gland anlage tumor: cytologic features in a case examined by fine-needle aspiration

The cytologic features in fine-needle aspirates from a rare benign nasopharyngeal salivary gland anlage tumor in a newborn boy are described and commented on, regarding therapeutically important differential diagnoses.

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.

A microtransplantation approach for cell suspension grafting in the rat Parkinson model: a detailed account of the methodology

Shortcomings of current techniques used for the intracerebral transplantation of ventral mesencephalic dopamine neurons include low graft survival, high variability, considerable implantation trauma and suboptimal graft integration. In order to overcome these limitations, we have adopted a microtransplantation approach which allows precise and reproducible implantation of ventral mesencephalon cell suspensions at single or multiple sites with minimal trauma and improved survival and integration of the grafted neurons [Nikkhah et al. (1994) Brain Res. 633, 133-143]. The present study was undertaken to determine the influence of different grafting parameters as well as the time-course of development of micrografted dopaminergic neurons and to devise an optimal microtransplantation procedure in the rat Parkinson model, Rats with unilateral 6-hydroxydopamine lesions of the nigrostriatal pathway received four graft deposits of either 0.25, 0.5, 1.0 or 2.0 microliters along four injection tracts (150,000 cells/microliters) using either a glass capillary (o.d. 50-70 microns) or a regular cannula (o.d. 0.50 mm, metal cannula grafts). At one, two and 12 weeks postgrafting (capillary grafts) and at 12 weeks postgrafting (metal cannula grafts) dopamine neuron survival and graft volumes were measured and the implantation trauma assessed by glial fibrillary acidic protein expression. The results demonstrate that single deposits of 50,000-75,000 cells in 0.5 microliter, implanted with a glass capillary, provide the best environment both for dopaminergic and non-dopaminergic neuron survival. Grafts implanted with the glass capillary showed much weaker long-term glial fibrillary acidic protein expression along the injection tract and around the implants than was the case in grafts implanted with the thicker metal cannula. Optimal graft integration and minimal disturbances of host brain structures can reliably be achieved by small-sized implants (20,000-35,000 cells/deposit). Tyrosine hydroxylase-positive fiber outgrowth from micrografted dopaminergic neurons was seen not only in the surrounding caudate-putamen, but also along white matter tracts into the nucleus accumbens and the overlying cerebral cortex. Spreading of dopaminergic micrografts over multiple small deposits rather than increasing the volume of single grafts gave more extensive reinnervation of the entire host striatum. The micrografting technique provides a useful tool to improve graft-host interactions in the rat Parkinson model, and it allows more precise and reproducible quantitative studies on dopamine neuron survival and growth in intrastriatal ventral mesencephalon transplants. This technique should also be highly useful for the intracerebral implantation of cells derived from primary cultures or cell lines [Gage and Fisher (1991) Neuron 6, 1-12].

Diseases and environmental contaminants in seals from the Baltic and the Swedish west coast

Investigations have shown that Baltic grey seal (Halichoerus grypus) and ringed seal (Phoca hispida) suffer from a disease complex described as a primary lesion in the adrenals causing secondary reactions in various other organs. Studies on historical Baltic grey seal skull bone material show that the prevalence of affected animals started to increase after World War II. The disease complex explains the dramatic decrease in the Baltic grey and ringed seal population during the 1960s and 1970s and is believed to be caused by environmental pollutants. In 1988, about 60% of the harbor seal population (Phoca vitulina) along the Swedish west coast and in the southwestern part of the Baltic died in the PDV epizootic (Phocine Distemper Virus). Whether the course of the epizootic was altered by environmental pollutants is still an open question. Studies on historical harbor seal skull bone material from both the Baltic and the Swedish west coast show that the incidence of skull bone lesions has also increased in these populations since World War II, indicating the presence of unnatural stress factors. After the epizootic, the harbor seal populations both in the Baltic and along the Swedish west coast have increased in number. Chemical analysis of tissues has been performed on the three seal species collected in various areas of the Baltic and the Swedish west coast. The concentrations of 17 metals and non-metal elements, sDDT and PCBs, DDE and PCB methylsulfones, toxaphene, chlordanes, polybrominated diphenyl ethers, PCDDs and PCDFs have been determined in selected groups of seals in order to determine spatial, species and age variations in concentrations. Furthermore, healthy animals have been compared to diseased animals. Spatial variation was found mostly within the group of organohalogenated compounds, a group of contaminants where a strong covariation between the various compounds was also found. On the basis of the analytical results as well as the pathological findings on Baltic seals, the group of DDE and PCB methyl sulfones is tentatively suggested to be more important in explaining the disease complex than coplanar structures including dioxins.

Peripartum cardiomyopathy--three cases

Three cases of peripartum cardiomyopathy (PPCM) are presented, each illustrating a clinically important aspect of the disorder. One patient survived despite extreme haemodynamic deterioration, one died suddenly 2 months post partum although clinically recovered, and one died during a subsequent pregnancy. The cases demonstrate the severity and the unpredictable course of PPCM, which remains a challenge both to scientists and to clinicians.

Accumulation of T lymphocytes and expression of interleukin-2 receptors in nonrheumatic stenotic aortic valves

OBJECTIVES

Cell-specific antibodies were used to identify immunocompetent cells in a comparison of valves from patients who had symptomatic tricuspid aortic stenosis with subjects who had no evidence of valvular heart disease.

BACKGROUND

Nonrheumatic valvular aortic stenosis is the most common valvular heart disease among adults. The biologic processes involved in the development of this disease are poorly understood.

METHODS

Tricuspid stenotic aortic valves were obtained from 19 patients undergoing surgery for nonrheumatic valvular aortic stenosis, and 10 control valves were collected at autopsy. The valves were fixed in formaldehyde, cryosectioned and stained with antibodies against fibroblasts, endothelial cells, macrophages, T lymphocytes and interleukin-2 receptors. A subset of valves were also analyzed with antibodies against T-helper cells and cytotoxic T cells.

RESULTS

Stenotic valves were characterized by a basal accumulation of calcium deposits and a cell-rich subendothelial thickening. The immunohistologic analysis indicated that the cells in the subendothelial connective tissue were fibroblasts. T lymphocytes appeared to be the most common cell type in the vicinity of the calcium deposits and were also found close to the endothelial lining of the valves. T-helper cells were more frequent than cytotoxic T cells. Expression of interleukin-2 receptors occurred at the same location as T lymphocytes. Control valves lacked subendothelial thickening and contained only few cells reacting with antibodies against lymphocytes and macrophages.

CONCLUSIONS

The presence of activated T lymphocytes in tricuspid stenotic valves suggests that immunologic mechanisms may be involved in the etiology of nonrheumatic aortic stenosis.

Release of 5'-terminal deoxyribose-phosphate residues from incised abasic sites in DNA by the Escherichia coli RecJ protein

Excision of deoxyribose-phosphate residues from enzymatically incised abasic sites in double-stranded DNA is required prior to gap-filling and ligation during DNA base excision-repair, and a candidate deoxyribophosphodiesterase (dRpase) activity has been identified in E. coli. This activity is shown here to be a function of the E. coli RecJ protein, previously described as a 5'-->3' single-strand specific DNA exonuclease involved in a recombination pathway and in mismatch repair. Highly purified preparations of dRpase contained 5'-->3' exonuclease activity for single-stranded DNA, and homogeneous RecJ protein purified from an overproducer strain had both 5'-->3' exonuclease and dRpase activity. Moreover, E. coli recJ strains were deficient in dRpase activity. The hydrolytic dRpase function of the RecJ protein requires Mg2+; in contrast, the activity of E. coli Fpg protein, that promotes the liberation of 5'-->3'Rp residues from DNA by beta-elimination, is suppressed by Mg2+. Several other E. coli nucleases, including exonucleases I, III, V, and VII, endonucleases I, III and IV and the 5'-->3' exonuclease function of DNA polymerase I, are unable to act as a dRpase. Nevertheless, E. coli fpg recJ double mutants retain capacity to repair abasic sites in DNA, indicating the presence of a back-up excision function.

On the relationship between crown form and clinical features of the gingiva in adolescents

The purpose of the present study was to examine the relationship between the form of the crowns in the maxillary front tooth segment and (1) a group of morphological characteristics and (2) the thickness of the gingiva. 108 subjects devoid of symptoms of destructive periodontal disease were examined regarding, e.g., probing depth, thickness of the free gingiva, width of the keratinized gingiva and the contour of the marginal gingiva. From clinical photographs of the maxillary front tooth region, the width (at the apical third--CW) and the length (CL) of the crowns of the 6 front teeth were determined. A CW/CL-ratio was calculated for each tooth and averaged for each tooth region. The individual mean CW/CL-ratio values for the central incisors were ranked. After correction for incisal attrition, the 10 subjects ranked highest and the 10 ranked lowest were selected as having either a long-narrow (group N) or a short-wide (group W) form of the crown of the tooth. The data for each of the examined parameters were averaged for each tooth region in each subject and mean values for subjects in groups W and N were compared using the Student t-test. Stepwise multiple regression analysis, including data from the whole sample, was performed for each tooth region with the thickness of the free gingiva as the dependent variable.(ABSTRACT TRUNCATED AT 250 WORDS)

GTPase activity of a bacterial SRP-like complex

We have recently identified a protein (SRPM54) in Mycoplasma mycoides homologous to SRP54, a subunit of the mammalian signal recognition particle (SRP). This protein forms a complex with a mycoplasma RNA related to the RNA component of SRP. We have now demonstrated that the protein has an intrinsic GTPase activity in vitro and kinetic parameters for the enzymatic reaction have been determined. The GTPase activity was not significantly affected by the presence of the mycoplasma SRP RNA. Different regions of the SRPM54 protein were expressed as recombinant proteins in E. coli and were purified to near homogeneity. On the basis of the properties of these SRPM54 fragments two different functional domains of the protein could be distinguished. An N-terminal part was found to contain the GTPase activity and this domain had approximately the same kinetic properties as the full-length protein. Another domain corresponding to a C-terminal fragment contained the RNA binding activity as shown using an assay based on the retention of RNA-protein complexes to nitrocellulose filters.

Detection of Pneumocystis carinii DNA in sputum and bronchoalveolar lavage samples by polymerase chain reaction

A polymerase chain reaction (PCR)-based assay was developed for the detection of Pneumocystis carinii DNA in induced sputum and bronchoscopic alveolar lavage samples. The primer pair was selected from the published sequence of the thymidylate synthase gene of P. carinii derived from infected rats. The amplified DNA fragment of 403 bp was detected by agarose gel electrophoresis and by Southern and slot blot hybridization. No positive reaction was seen with DNA from different microorganisms typically found in the respiratory tract. P. carinii DNA was demonstrated in 30 of 42 sputum samples from immunosuppressed patients, whereas 21 of 42 sputum samples were positive by indirect immunofluorescence (IFL). Among the 42 patients, 14 were receiving prophylactic chemotherapy. In that group, PCR detected P. carinii in nine sputum samples, whereas IFL detected P. carinii in only four sputum samples. A positive PCR result was also seen in 5 of 43 IFL-negative bronchoscopic alveolar lavage samples from patients with respiratory symptoms. The PCR assay detected 10 copies of the target DNA, which corresponds to 10(-18) g of the specific P. carinii sequence. The results indicate that PCR amplification in combination with DNA hybridization is specific and is a more sensitive diagnostic method than IFL for the detection of P. carinii.

Aortic valve replacement in octogenarians with aortic stenosis: a case-control study

OBJECTIVES

This study was designed to compare the results of aortic valve replacement in patients greater than or equal to 80 years old with those in patients 65 to 75 years old.

BACKGROUND

Aortic valve replacement may be potentially more complicated and require the use of more resources when performed in octogenarians rather than in younger patients. Few hard data on this possibility are available.

METHODS

The study group comprises all 44 patients greater than or equal to 80 years old (mean age 82 years) who underwent aortic valve replacement at our institution between January 1981 and July 1989. A control group of 83 patients with a mean age of 70 years was matched with the study group for gender and approximate date of valve replacement. Before operation, 86% of the older patients versus 36% of the younger patients were in New York Heart Association functional class III or IV (p less than 0.001). Data were retrospectively collected from hospital records and a self-assessment telephone interview was conducted.

RESULTS

The early mortality rate was 14% in the older group versus 4% in the younger group (p = 0.045). The duration of respirator support, intensive care and the total duration of the hospital stay did not differ significantly between groups. The incidence of postoperative low cardiac output syndrome was higher in the older group (p = 0.049), but the incidence of late valve-related complications was similar in the two groups. The 2-year survival rate (including data on patients who died early) was 73% in the older group and 90% in the younger group (p = NS). Six months postoperatively all patients but one were in functional class I or II.

CONCLUSIONS

Although the patients greater than or equal to 80 years old had a poorer preoperative status than that of younger patients, aortic valve replacement in this group did not require more use of hospital resources and resulted in a clinical improvement comparable to that of younger patients.

Mandibular function before orthodontic treatment

Two-hundred-and-forty-five consecutive prospective orthodontic patients and 245 controls matched for age, sex, and residence, but with minor need of orthodontic treatment, were examined. The functional examination of the masticatory system was made according to Carlsson and Helkimo (1972), and Helkimo (1974). According to dysfunction index (Helkimo, 1974), 33.5 per cent of the patients and 21.6 per cent of the controls had a moderate, and 18.9 and 7.8 per cent respectively, a severe dysfunction. The corresponding figures for symptoms were 16.7 and 4.9 per cent respectively. In the patient group the frequency of signs and symptoms was higher in the older age group and in the girls. Orthodontic patients appeared to be at greater risk of craniomandibular disorders (CMD) than individuals with minor need of treatment.

Identification of Salmonellae with the 4-methylumbelliferyl caprilate fluorescence test

We have tested 750 Salmonella strains and 130 strains of other species of the family Enterbacteriaceae with the 4-methylumbelliferyl caprilate reagent (MUCAP) test. The MUCAP test is a fluorescence test for rapid identification of Salmonella strains. The non-Salmonella strains were strains sent for identification as suspected Salmonella strains and thus have phenotypes similar to those of Salmonella strains. All 748 tested Salmonella strains of subgroups I, II, III, and IV were positive in the MUCAP test. Of the two tested rare Salmonella subgroup V strains, one was positive and the other was negative. In the selected material containing strains with phenotypes similar to those of Salmonella strains, only one Hafnia alvei strain of 130 Enterbacteriaceae bacteria tested was positive. The fluorescence of the H. alvei strain, the six tested Salmonella dublin strains, and the positive Salmonella subgroup V strain was weaker than that of the other salmonellae. The MUCAP assay is simple and is performed within 5 min. With an almost 100% sensitivity for Salmonella strains, apart from a single Salmonella subgroup V strain, we found the MUCAP test to be a convenient complement to traditional biochemical identification methods, especially for atypical and unusual Salmonella strains.

DNA haplotype analysis suggests linkage disequilibrium in the human insulin receptor gene

Haplotypes of the insulin receptor gene were resolved in parents from Scandinavian nuclear families by studying the segregation of seven restriction fragment length polymorphisms (RFLPs). Of 97 unrelated parents, 41 had non-insulin-dependent diabetes mellitus (NIDDM). Considerable linkage disequilibrium in the region of the insulin receptor gene was found. Pairwise non-random associations were found between proximate RFLP sites, indicating the absence of recombinational hot spots between these sites. Thus, association studies between DNA polymorphisms at this locus and disease susceptibility genes could well be feasible in this population. Differences in the distribution of insulin receptor haplotypes were examined between NIDDM patients and healthy subjects. However, the differences observed were not statistically significant.

Tryptase in nasal lavage fluid after local allergen challenge. Relationship to histamine levels and TAME-esterase activity

The activation of mast cells is generally considered to be an important trigger mechanism in the immediate allergic response. This study focused on the determination of three markers of mast cell activation after an allergen challenge. Nasal allergen challenges were performed in 25 subjects with seasonal allergic rhinitis using three allergen doses increasing in 10-fold steps in a standardised nasal lavage model for the subsequent recovery of the markers of mast cell activation. The levels of histamine and tryptase in the nasal lavage fluid were determined using radioimmunoassays, while the TAME-esterase activity was determined using a radiochemical technique. The nasal symptoms obtained on challenge were assessed using a scoring technique. The allergen challenge resulted in significant increases in the levels of all three markers, tryptase, histamine and TAME-esterase. In the individual measurements after the challenges there was a highly significant correlation between the TAME-esterase levels and the tryptase levels (r = 0.71; P less than 0.001), while the generation of histamine and tryptase was not significantly correlated. When comparing the cumulative generation of the three markers, significant correlations were found between all three. Allergen challenges in six non-allergic controls using the same technique did not result in any increase in tryptase levels. The findings suggest that the determination of tryptase in nasal lavage fluid may be a valuable indicator of mast cell activation in the upper airways.

[PCB methyl sulphone: comparison of tissue levels in Baltic grey seals and a Yusho patient]

Methyl sulphone metabolites of PCB and DDE were isolated from different tissues of a Baltic grey seal (Halichoerus grypus). Main components in the seal blubber were identified as 3-MeSO2-2,2',4',5,5'-pentaCB, 4-MeSO2-2,2',4',5,5'-pentaCB, 3-MeSO2-p,p'-DDE, 4-MeSO2-2,2',3',4',5-pentaCB and 4-MeSO2-2,2',3,4',5',6-hexaCB. Liver and lung in the seal contained different MeSO2-PCB pattern compared to all other tissues. These levels in the both tissues were estimated to be 28 and 15 ppm (lipid basis) which corresponded to the same level as the PCB. Concentrations of MeSO2-PCB in any tissues of a Yusho patient were low compared to those in the seal.

Digoxin-verapamil interaction: reduction of biliary but not renal digoxin clearance in humans

The interaction between digoxin and verapamil was studied in six patients (mean age +/- SD, 61 +/- 5 years) with chronic atrial fibrillation. The effects of adding verapamil (240 mg/day) on steady-state plasma concentrations and renal and biliary clearances of digoxin were studied in a crossover manner. The biliary clearance of digoxin was determined by a duodenal perfusion technique. Verapamil induced a 44% increase in steady-state plasma concentrations of digoxin, from 0.80 +/- 0.24 to 1.15 +/- 0.40 nmol/L (p less than 0.01). The biliary clearance of digoxin decreased by 43%, from 187 +/- 89 to 101 +/- 55 ml/min (p less than 0.05), in the presence of verapamil, whereas the renal clearance was unaffected (153 +/- 31 versus 173 +/- 51 ml/min; difference not significant). Our results indicate that the main inhibitory effect of verapamil on digoxin elimination is on the biliary route.

Periodontal characteristics in individuals with varying form of the upper central incisors

It has been suggested that the variation in the morphology of the human periodontium may be related to the shape and form of the teeth. Furthermore, the severity of symptoms of periodontal disease have been proposed to differ among these various morphologic entities or "biotypes". The aim of the present study was (i) to identify individuals with markedly different crown forms and (ii) to determine probing pocket depth, probing attachment level and amount of gingival recession that had occurred at different teeth and tooth surfaces in such individuals. Clinical photographs of the maxillary incisor tooth region of 113 subjects who had been recruited for a long-term study on periodontal disease were available. The length (CL) and width (CW) of the crowns were determined and the CW/CL ratio was calculated for each tooth. 10% in each tail, 11 subjects in each group, were arbitrarily chosen as having either a long-narrow (N) or a short-wide (W) form of the central incisors. The probing pocket depth, probing attachment level and gingival recession data available from all subjects and subjects in groups W and N were compared and analyzed using the Student t-test and multiple regression analysis. The result from the analyses demonstrated that: (1) subjects with a long-narrow form of the upper central incisors had experienced more recession of the gingival margin at buccal surfaces than subjects who had a short-wide tooth form; (2) there was a significant influence of the CW/CL-ratio on the probing attachment level (p less than 0.05) and the amount of gingival recession (p less than 0.01) on buccal tooth surfaces.(ABSTRACT TRUNCATED AT 250 WORDS)

Unnecessary deaths from valvular aortic stenosis

The annual mortality from aortic valvular stenosis was calculated among potential candidates for surgical replacement of the aortic valve. From the Swedish Central Register of Causes of Death, 70 patients below the age of 80 years who had died from aortic stenosis during a 1-year period in the County of Stockholm (population 1.5 million), were identified. A retrospective analysis of their medical records showed that 37 individuals were suitable candidates for surgery. The presence of aortic stenosis had been verified at autopsy in 31 (84%) patients. The remaining six patients (16%) had their aortic stenosis diagnosis established by a thorough non-invasive investigation performed before death. Although typical signs and symptoms of aortic stenosis were recorded in all 37 patients, only six (16%) of them had been considered by their physicians to be suitable candidates for surgery prior to death. The deceased patients were compared with a group of 68 patients who had undergone aortic valve replacement for aortic stenosis during the same period. There were no significant differences between the two groups with regard to symptoms and clinical findings, except for a higher incidence of syncope in the operated group. It is concluded that, of 105 (68 surgically treated and 37 deceased) eligible patients with aortic stenosis, 37 individuals did not receive surgical care in time. The reason for this was probably insufficient knowledge of the curability of the disease.

Measurement of histamine in nasal lavage fluid: comparison of a glass fiber-based fluorometric method with two radioimmunoassays

The determination of histamine in nasal secretions and nasal lavage fluid may be of importance to monitor activation of histamine containing cells in the nasal cavity. However, such studies have been besieged by controversy, specifically to findings of changes in histamine levels in relation to allergenic stimulation. This controversy may be due to the specificity and accuracy of the various methods used to determine histamine in the nasal fluid. We have therefore applied and compared three new methods to determine histamine in nasal lavage fluids obtained before and after allergen challenge in normal subjects and patients with allergic rhinitis. We used a fluorometric glass fiber-based histamine method (FHR) and two RIAs, I and II. The FHR (detection limit, 7.0 nmol) and the RIA II (detection limit, 0.2 nmol) are specific for histamine itself, whereas the RIA I (detection limit, 18.0 nmol) measures mainly methylhistamine and cross-reacts to some extent with histamine. The histamine levels in the nasal lavage fluids from the nasal challenges demonstrated histamine values between 100 and 2000 nmol/L of histamine with significantly higher levels in the postallergen challenges for the allergic subjects as compared to the normal control subjects. The FHR correlated well with the RIA I and RIA II methods with correlation coefficients of 0.77 to 0.88 (p less than 0.001), respectively. However, the RIA I (methylhistamine antibody) always demonstrated absolute histamine values 5% to 20% of values measured by the RIA II (at the level of cross-reactivity to histamine).(ABSTRACT TRUNCATED AT 250 WORDS)

MRI contrast media for the liver. Efficacy in conditions of acute biliary obstruction

The authors investigated in a rat model the efficacy of magnetic resonance imaging (MRI) contrast media for evaluating the liver in conditions of acute biliary obstruction. Two liver-specific MRI contrast media, Cr-DEHIDA and Mn-DPDP, and the nonspecific agent Gd-DTPA were studied in normal rats and in rats whose bile ducts had been ligated before administration of the contrast medium. Images were made using a 2.4 T animal MRI system, and intensity enhancement of liver after contrast medium injection was calculated. Metal analyses of serum and liver tissue and T1 and T2 measurements on liver samples in vitro were performed. The differences in image intensity enhancement of liver between normal rats and rats with ligated bile ducts were not significant for any of the three contrast media. Imaging with Mn-DPDP resulted in the highest intensity enhancement of the liver compared with Cr-DEHIDA and Gd-DTPA. Contrast media concentrations in liver tissue were not significantly different between normal rats and rats with ligated bile ducts; however, Cr-DEHIDA concentrations in serum were higher after bile duct ligation. In vitro measurements of liver tissue indicated unique relaxation properties for Mn-DPDP. This investigation indicates that the contrast media studied may be useful in situations where suspected liver pathology is complicated by acute biliary obstruction.