Vitamin A antagonizes calcium response to vitamin D in man

For unknown reasons, the highest incidence of osteoporosis is found in northern Europe. In these populations, the sunlight exposure is limited and the vitamin A intake is high. The interaction between vitamin A and D has been the subject of several in vitro and animal studies. We have studied the acute effects of vitamin A and D on calcium homeostasis in 9 healthy human subjects. We compared the effect of (i) 15 mg of retinyl palmitate, (ii) 2 microg of 1,25-dihydroxyvitamin D3 [1,25(OH)2D3], (iii) 15 mg of retinyl palmitate plus 2 microg of 1,25(OH)2D3, and (iv) placebo in a double-blind crossover study. The subjects took vitamin preparations at 10:00 p.m. and the following day blood samples were collected five times from 8:00 a.m. to 4:00 p.m. Serum levels of 1,25(OH)2D3 and retinyl esters increased (1.7-fold and 8.3-fold, respectively; p < 0.01). As expected, serum calcium (S-calcium) increased (2.3%; p < 0.01) and S-parathyroid hormone (PTH) decreased (-32%; p < 0.05) after 1,25(OH)2D3 intake. In contrast, retinyl palmitate intake resulted in a significant decrease in S-calcium when taken alone (-1.0%; p < 0.05) and diminished the calcium response to 1,25(OH)2D3 after the combined intake (1.4%; p < 0.01). S-PTH was unaffected by retinyl palmitate. No significant changes in serum levels of the degradation product of C-telopeptide of type I collagen (CrossLaps), or U-calcium/creatinine levels were found. In conclusion, an intake of vitamin A corresponding to about one serving of liver antagonizes the rapid intestinal calcium response to physiological levels of vitamin D in man.

Evidence for target-specific outgrowth from subpopulations of grafted human dopamine neurons

Clinical and experimental grafting in Parkinson's disease has shown the need for enhanced survival of dopamine neurons to obtain improved functional recovery. In addition, it has been suggested that a limited number of surviving dopamine neurons project to the dopamine-denervated host striatum. The aim of this study was to investigate if subpopulations of ventral mesencephalic dopamine neurons project to their normal targets, i.e., dorsal vs. ventral striatum. Following implantation of human ventral mesencepahlic tissue into the lateral ventricle of dopamine-depleted rats, human-derived dopamine reinnervation was achieved both in dorsal and ventral striatum. Treatment with the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) resulted in a degeneration of tyrosine hydroxylase (TH)-immunoreactive nerve fibers in dorsal striatum but not in ventral areas in some animals, while MPTP was without effect in other animals. TH-immunoreactive neurons were small and appeared shrunken in animals carrying grafts affected by the MPTP treatment. In conclusion, grafted dopamine neurons projected nerve fibers into areas that they normally innervate. Thus, when searching for factors that may enhance survival of grafted dopamine neurons it is important to study which subpopulation(s) of ventral mesencephalic dopamine neurons is affected, such that a proper reinnervation may be achieved.

Prescription drug use, diagnoses, and healthcare utilization among the elderly

BACKGROUND

More elderly patients affected by severe and chronic diseases are treated in primary care. Reports on the use of prescription drugs by the general elderly population are scarce, and more investigations are needed to optimize pharmaceutical care for these patients.

OBJECTIVE

To analyze prescription drug use, diagnoses, and healthcare utilization among noninstitutionalized elderly patients.

DESIGN

Retrospective cohort study.

SETTING AND PATIENTS

All people > or =65 years old (n = 4642) living in the community of Tierp, Sweden, in 1994 were included. Prescription drug use and healthcare utilization have been registered for all inhabitants of the community since 1972. Information about filled prescriptions and diagnoses were obtained from a computerized research register.

RESULTS

Prescription drug use was high among the elderly (78%); the most used pharmacologic groups were cardiovascular, nervous system, and gastrointestinal medications. Women used more prescription drugs than men (average 4.8 vs. 3.8) and had more nonfatal diagnoses. Use of five or more different prescription drugs during 1994 was common (39.0%), and multivariate analysis showed that the greatest number of primary care visits occurred with multiple drug use (> or =5 drugs over 1 y).

CONCLUSIONS

This study shows an extensive multiple drug use among elderly people living at home. Whether this multiple drug use per se is harmful to the patients or not could not be evaluated in this study. Further focused investigations are needed to assess the effect of multiple drug use in an elderly population.

Giving advice on cost effective measures for a cleaner Baltic Sea: a challenge for science

The Baltic Sea is one of the world's seas that is most severely affected by human activities. Although there is an international agreement that nutrient input to the Baltic should be reduced, the measures taken so far have not resulted in major reductions in nutrient inputs nor in environmental improvements. The reasons for this are partly due to lack of knowledge on large-scale relationships and couplings between physics, biogeochemistry and ecological properties. But there is also a lack of overall drainage basin-wide analyses on cost-effective measures. There is a danger in making the wrong decisions, e.g. implement reduction schemes that are at worst ineffective or at best, far from cost effective. Researchers from many disciplines are faced with a common challenge: To develop a decision-support system, which can be used as the scientific base for cost-effective measures for the entire Baltic Sea. Such an effort is now being made within the research program MARE (http://www.mare.su.se).

Cytotoxicity of digitoxin and related cardiac glycosides in human tumor cells

The saponin digitonin, the aglycone digitoxigenin and five cardiac glycosides were evaluated for cytotoxicity using primary cultures of tumor cells from patients and a human cell line panel (representing different cytotoxic drug-resistance patterns). Of these seven compounds, proscillaridin A was the most potent (IC(50): 6.4--76 nM), followed by digitoxin, and then ouabain, digoxin, lanatoside C, digitoxigenin and digitonin. Correlation analysis of the log IC(50) values for the cell lines in the panel showed that compound cytotoxicity was only slightly influenced by resistance mechanisms that involved P-glycoprotein, topoisomerase II, multidrug resistance-associated protein and glutathione-mediated drug resistance. Digitoxin and digoxin expressed selective toxicity against solid tumor cells from patients, while proscillaridin A expressed no selective toxicity against either solid or hematological tumor cells. The results revealed marked differences in cytotoxicity between the cardiac glycosides, both in potency and selectivity, and modes of action for cytotoxicity that differ from that of commonly used anticancer drugs.

The functional role of a bicuculline-sensitive Ca2+-activated K+ current in rat medial preoptic neurons

A Ca2+-activated K+ current was identified in neurons from the rat medial preoptic nucleus. Its functional role for the resting potential and for impulse generation was characterised by using the reversible blocking agent bicuculline methiodide. Acutely dissociated neurons were studied by perforated-patch recordings. The effect of bicuculline methiodide was investigated under voltage-clamp conditions to clearly identify the current affected. At membrane potentials > -50 mV, bicuculline methiodide rapidly (< 1 s) and reversibly blocked a steady outward current. Half-saturating concentration was 12 microM. The current amplitude increased with potential in the range -50 to 0 mV. The bicuculline-sensitive current was identified as an apamin-sensitive, Ca2+-dependent K+ current. It was neither affected by the GABAA receptor blocker picrotoxin (100 microM) nor by a changed pipette Cl- concentration, but was affected by substitution of extracellular K+ for Na+. The current was dependent on extracellular Ca2+ and was sensitive to 1 microM apamin but not to 200 nM charybdotoxin. A role for the Ca2+-dependent K+ current in setting the resting potential and controlling spontaneous firing frequency was observed under current-clamp conditions. Bicuculline methiodide (100 microM) induced a positive shift (5 +/- 1 mV; n = 18) of resting potential in all neurons tested. In the majority of spontaneously firing neurons, the firing frequency was reversibly affected, either increased or decreased depending on the cell, by bicuculline methiodide.

Assembly of laminin polymers is dependent on beta1-integrins

Recent reports suggest that laminin deposition is controlled by the cell via specific receptors, one of which is dystroglycan. In this study, the involvement of beta1-integrins in this process was investigated by comparing beta1-integrin-deficient cells of different phenotypes with their normal counterparts. Normal embryonic stem (ES) cells and embryoid bodies (EBs) derived from them were found to deposit cell-associated laminin into fibrillar networks, and in the EBs a basement membrane was assembled under the primitive endoderm. beta1-deficient ES cells and their EBs formed only small amounts of dot-like laminin deposits. Skeletal myotubes formed after prolonged differentiation in EBs were found to be surrounded by laminin, nidogen, and perlecan by immunofluorescent staining irrespective of the presence of beta1-integrins on the myotubes. However, at the electron microscope level only very thin sheet-like structures were detected close to the beta1-deficient myotubes, while the wt myotubes formed thick basement membranes. An epithelial cell line, GE11, derived from the beta1-integrin-deficient ES cells was also unable to assemble laminin on the cell surface, while transfection of the cells with the integrin beta1 subunit resulted in formation of a dense laminin network. Taken together, these results suggest that dystroglycan and beta1-integrins can both contribute to the recruitment of laminin to cell surfaces and that integrins are required at a subsequent step in the formation of basement membranes.

Incidence of newly diagnosed heart failure in UK general practice

AIM

To estimate the incidence rate of heart failure in the general population and to assess risk factors associated with the occurrence of newly diagnosed heart failure.

METHODS

From the source population that was derived from the UK General Practice Research Database, we identified patients aged 40--84 years newly diagnosed with heart failure in 1996, and estimated incidence rates. We sent questionnaires to a random sample of heart failure patients (N=1200) and performed a nested case-control analysis to assess risk factors for heart failure.

RESULTS

The overall incidence rate for heart failure was 4.4 per 1000 person-years in men and 3.9 per 1000 person-years in women. The incidence increased steeply with age in both sexes. The relative risk of heart failure was 2.1 (95% C.I.: 1.7--2.6) among men compared with women less than 65 years old and 1.3 (95% C.I.: 1.2--1.4) above the age of 65. Slightly more than half of the cases were categorized in NYHA III--IV at the time of the first diagnosis. Within one month of initial diagnosis 62% of the men and 50% of the women were referred to specialists and/or hospitalized for heart failure. Smoking, hypertension, diabetes, obesity were independently associated with heart failure as well as history of distant dyspnoea. Coronary heart disease was the most common cause of heart failure with a greater relative prevalence in men than women.

CONCLUSION

Incident heart failure cases mainly comprised elderly men and women frequently burdened with several diseases in general practice. Women had a lower incidence of heart failure than men. However, traditional risk factors such as smoking, hypertension, obesity, diabetes and dyspnoea appeared to confer the same relative increase in heart failure risk among women and men.

Left sided vocal cord paralysis: a newly recognized late complication of mediastinal irradiation

BACKGROUND AND PURPOSE

To evaluate the incidence of vocal cord paralysis in a group of breast cancer patients treated with post operative radiation therapy after radical mastectomy.

MATERIALS AND METHODS

A group of 150 patients operated with total mastectomy and axillary clearance received, in 1963-1965, post-operative radiotherapy to the parasternal, axillary and supraclavicular lymph node regions. The cohort has now been followed up to 34 years.

RESULTS

Eleven of the 12 vocal cord paralyses were left sided, although the breast cancer was almost equally distributed as left- and right-sided (55 vs. 45%). The symptoms did not appear until 2-25 years after irradiation. Series 1 (treated with (60)Co photons) developed 5% recurrent nerve paralysis (RNP) after a median time of 19.0 years compared with 10% and a much earlier appearance (3.5 years) for series 2 (treated with both (60)Co photons and electrons). A reconstruction of the dose plan shows that an unintentional overlap of the fields resulted in hotspots in the tracheo-oesophageal groove, where parts of the tissue received 120-130% of the prescribed dose.

CONCLUSIONS

A left-sided vocal cord paralysis of patients treated with mediastinal radiotherapy might not indicate only tumour recurrence but also mediastinal fibrosis. Small differences in patient positioning cannot be excluded as the cause of the difference in the two series. We postulate that other more subtle damage to the vagus nerve may occur without being recognized as late radiation injury.

Lifetime measurements of metastable states in Fe+

The lifetime of two metastable levels in Fe+ has been measured by laser probing of a stored ion beam. In the dense spectrum of Fe+, the metastable levels a (6)S(5/2) and b (4)D(7/2) were selected and their lifetimes were determined to be 230 +/- 30 and 530 +/- 30 ms, respectively. The lifetimes are compared with previous theoretical results. Metastable lifetime measurements of Fe+ are of great importance for interpretation of spectra from astronomical objects. The present experiment opens for the possibilities to investigate lifetimes of metastable states in complex atomic ions, which have, so far, been unexplored.

Histologic grading in breast cancer--reproducibility between seven pathologic departments. South Sweden Breast Cancer Group

Histologic grade, including tubular formations, nuclear grade, and mitotic activity, is a well-documented prognostic factor in breast cancer. In comparison with other prognostic parameters, the evaluation of histologic grade is cheap and can be performed, in principle, in all cases of breast cancer. One possible disadvantage is that the evaluation may vary between different pathological departments. The aim of the present work was therefore to study the reproducibility of the histologic grading system by distributing haematoxylin-erythrosin-stained slides from 93 invasive breast cancers to the seven pathology departments within the southern healthcare region of Sweden. The evaluation was performed blindly and without any knowledge of other clinical parameters. In 31% of the cases the same histologic grade was obtained for all departments. The overall mean kappa was 0.54, indicating a moderate reproducibility. Of the three factors included in histologic grade, the agreement was best for tubular formations and poorest for nuclear grade and mitotic activity. The overall moderate reproducibility should be considered when the clinical usefulness of histologic grading is compared with other prognostic instruments.

Resonance-enhanced two-photon ionization of ions by Lyman alpha radiation in gaseous nebulae

One of the mysteries of nebulae in the vicinity of bright stars is the appearance of bright emission spectral lines of ions, which imply fairly high excitation temperatures. We suggest that an ion formation mechanism, based on resonance-enhanced two-photon ionization (RETPI) by intense H Lyman alpha radiation (wavelength of 1215 angstroms) trapped inside optically thick nebulae, can produce these spectral lines. The rate of such an ionization process is high enough for rarefied gaseous media where the recombination rate of the ions formed can be 10(-6) to 10(-8) per second for an electron density of 10(3) to 10(5) per cubic centimeter in the nebula. Under such conditions, the photo-ions formed may subsequently undergo further RETPI, catalyzed by intense He i and He ii radiation, which also gets enhanced in optically thick nebulae that contain enough helium.

Immunohistochemical localization of retinoid binding proteins at the materno-fetal interface of the porcine epitheliochorial placenta

Retinol and retinoic acid that are potent modulators of gene expression are vital for development and growth of the conceptus. Apart from being transported across the placenta, retinol and retinoic acid may also be active in the placenta per se. Three proteins involved in 1) serum transport of retinol (retinol binding protein [RBP]), 2) cellular transport and metabolism of retinol (cellular RBP [CRBP] I), and 3) retinoic acid (cellular retinoic acid binding protein [CRABP] I), respectively, have been located by immunohistochemistry during gestation in the porcine placenta. This is a diffuse epitheliochorial placenta composed of areolar-gland subunits, where transport of larger molecules takes place, and interareolar regions, where gas-exchange and trophoblast absorption of hemotroph occur. Immunoreactive-RBP (ir-RBP) as well as CRBP I (ir-CRBP) was detected in uterine glands and in areolar trophoblasts, suggesting that RBP-retinol is secreted by the glands and absorbed by the trophoblasts. Both proteins were present also at the interareolar regions, with ir-CRBP in both the uterine epithelium and the apposing trophoblasts, but ir-RBP only in the former. The localization of ir-CRABP was, in contrast, strictly limited to interareolar trophoblasts. Together these findings suggest that 1) the areolar gland subunits are important for transport of retinol and retinol-RBP, and 2) retinoid binding proteins are involved in the development and growth of the porcine placenta.

[Patent ductus arteriosus. A common clinical problem in extremely premature infants]

An analysis was made of the incidence and treatment regimen of symptomatic patent ductus arteriosus (PDA) in 95 preterm infants treated 1997-1999 in a level three intensive care unit in Stockholm. 47 infants (49 percent) had PDA. Of these 17 infants were managed conservatively (fluid restriction and diuretics), 13 were treated with indomethacin, 10 underwent primary surgical ligation and 7 were treated with indomethacin first and surgery later on. The proportion of infants given "active" therapy (surgery and/or indomethacin) rose from 50 percent in 1997 to 85 percent in 1999. In a stepwise multiple regression analysis low birthweight, septicaemia and need for mechanical ventilation were all independently associated with PDA.

Bone tissue composition, dimensions and strength in female rats given an increased dietary level of vitamin A or exposed to 3,3',4, 4',5-pentachlorobiphenyl (PCB126) alone or in combination with vitamin C

In previous studies we have described structural and functional changes in rat bone tissue caused by 3,3',4,4',5-pentachlorobiphenyl (PCB126). Some of the effects caused by PCB126 resemble those found in vitamin C-deficient rats, as well as those found in rats with a high dietary intake of vitamin A. The present investigation was designed to determine if these PCB126-induced changes could be inhibited by addition of vitamin C to the drinking water and if they could be evoked by vitamin A administration. Five groups of female rats were used in this study, which lasted for 12 weeks. Three of the groups were exposed to PCB126 (total dose 320 microgram/kg, bw), either alone or in combination with vitamin C added to the drinking water (1 and 10 g/l, respectively). One group was given feed with increased level of vitamin A (600000 U/kg pellet) and the fifth group served as controls. Using peripheral quantitative computed tomography (pQCT), it was found that PCB126 increased trabecular density and cortical thickness, but reduced the trabecular area. Furthermore, maximum torque and stiffness of the humerus during torsional testing and serum osteocalcin levels were reduced by PCB126. Of the PCB126 induced effects observed, addition of vitamin C only inhibited the reduction of serum osteocalcin. Like PCB126 vitamin A supplementation increased the inorganic content and the bone density and also reduced the trabecular area and polar moment of inertia but did not increase the cortical thickness or reduce maximum torque, stiffness or serum osteocalcin level. Apparently, the effects induced by PCB126 are not mediated either via decreased vitamin C level or increased vitamin A level.

Timescale of evolution of late radiation injury after postoperative radiotherapy of breast cancer patients

PURPOSE

To evaluate the incidence and prevalence of various signs of late morbidity, their time of appearance and pattern of progression during an observation period up to 34 years in breast cancer patients treated with postoperative radiation therapy after radical mastectomy.

METHODS AND MATERIALS

A group of 71 breast cancer patients received in 1963-1965 aggressive postoperative telecobalt therapy to the parasternal, axillary, and supraclavicular lymph node regions after total mastectomy and axillary clearance. None of the patients received chemotherapy either prior to, or after the irradiation as part of their primary treatment. The prescribed dose to the three lymph node regions was 44 Gy in 11 fractions. Only two of the three fields were treated per day. This total dose was given in 16-17 fractions over 3-4 weeks. Because of the overlap of the supraclavicular and axillary fields, the dose received by the brachial plexus was not the dose that was prescribed. A retrospective dose calculation showed that the total dose to the brachial plexus was 57 Gy, delivered as a complex combination of 1.8 Gy, 3.4 Gy, and 5.2 Gy fractions. This cohort of patients has now been followed to 34 years and the late side effects of the treatment evaluated and scored.

RESULTS

This series is unique in the literature. There is no comparable report of a detailed long-term follow-up in a homogeneously treated group of patients with such a high survival, especially among the younger women, where it is almost 50% at 30 years. This is the reason that they were able to develop some of the very slowly evolving injuries. There was progression of many of the late effects in the period between 5 and 34 years. The more serious morbidities have increased progressively over the whole 34-year follow-up period. Ninety-two percent of the long-term survivors have paralysis of their arm. Other neurological findings included unilateral vocal cord paralysis among 5% of the patients, who developed the disease after a median time of 19 years. All of them were left-sided, indicating a mediastinal involvement of the recurrent nerve. Local recurrence or the appearance of a new primary tumor infiltrating or causing pressure on the recurrent nerve were vigorously investigated and excluded as possible causes of these symptoms.

CONCLUSION

The greatest risk for all cancer patients is the inadequate treatment of their disease, because this is inevitably lethal. The aggressiveness of the therapy and the acceptable risk of complications must therefore be balanced against the risk of recurrence. The neuropathy seems to be closely linked to the development of fibrosis around the nerve trunks. The use of large daily fractions, combined with hot spots from overlapping fields contributed to the severity of the complications.

Cellular invasion by Staphylococcus aureus involves a fibronectin bridge between the bacterial fibronectin-binding MSCRAMMs and host cell beta1 integrins

Although Staphylococcus aureus is primarily considered an extracellular pathogen, recent evidence suggests that this bacterium can invade a variety of nonprofessional phagocytic cells. Here we investigate the early stages of cellular invasion by S. aureus and determine the bacterial and host components that are required for this process. S. aureus expresses two cell surface-associated fibronectin (FN)-binding proteins (FnbpA and FnbpB) that mediate the interaction of the bacteria with both soluble and solid-phase FN in vitro. Using a mutant of S. aureus that lacks the expression of both Fnbps, we show that the expression of either protein is necessary for efficient uptake by the mouse fibroblast line GD25beta1A. Invasion could be inhibited by soluble recombinant proteins encompassing either the FN-binding D repeat region or the A region (and B repeats) of FnbpA, suggesting that the activities of both regions are important in this process. We demonstrate that FN is also required for invasion of this cell line. In the presence of FN-depleted fetal bovine serum, the invasion level was reduced by approximately 40% compared to in the presence of whole fetal bovine serum. Invasion could be further reduced by the addition of anti-mouse FN antibodies to the assay. Finally, we utilize a mutant mouse fibroblast line, which lacks beta1 integrin expression, to demonstrate that host cell beta1 integrins are necessary for efficient cellular invasion. The level of invasion of the mutant cell line GD25 was reduced by approximately 97% compared to the beta1-expressing complemented cell line GD25beta1A. In addition, invasion of the GD25beta1A cell line could be inhibited by an RGD-containing peptide, further implicating a role for integrins in this process. Based on these observations, we put forward a model of S. aureus invasion in which host FN forms a bridge between the bacterial Fnbps and host cell beta1 integrins, leading to bacterial uptake.

Brachial plexopathy after postoperative radiotherapy of breast cancer patients--a long-term follow-up

In 1963-1965 a group of 71 patients operated on for breast cancer with total mastectomy and axillary clearance were given aggressive postoperative telecobalt therapy to the axillary, supraclavicular and parasternal lymph node regions. The prescribed dose to these lymph node regions was 44 Gy in 11 fractions. Only two of the three fields were treated per day. Retrospective dose calculations showed that the total dose in the brachial plexus from the axillary and supraclavicular fields was c. 57 Gy in 16-17 fractions over 3-4 weeks. After a few years, symptoms and signs of brachial plexus injury appeared in many patients, which was reported in some early papers. The cohort has now been followed-up to 34 years. As expected, there was progression of both prevalence and severity of the late effects between 5 and 34 years and 11 of 12 patients who are still alive have paralysis of their arms. The neuropathy seems to be closely linked to fibrosis around the nerve trunks. The use of large daily fractions, in some cases combined with hot spots from overlapping fields, was certainly the cause of the complication.

Ipsilateral local recurrence in relation to therapy and morphological characteristics in patients with ductal carcinoma in situ of the breast

METHOD AND RESULTS

A standardized histopathological protocol has been designed, in which different histological characteristics of ductal carcinoma in situ (DCIS) are reported: nuclear grade (ng), growth pattern according to Andersen et al., necrosis, size of the lesion, resection margins and focality. Using this protocol a re-evaluation of a population-based consecutive series of 306 cases of DCIS has been done as well as a thorough clinical follow-up. After a median follow-up of 63 months, 13% have developed ipsilateral local recurrences, invasive and/or in situ. Ipsilateral local recurrence-free survival (IL-RFS) was significantly better for patients operated with mastectomy (ME) or breast conserving therapy (BCT) with radiotherapy (RT) than for patients operated with BCT without RT (5-year IL-RFS 96% vs 94% vs 79%, P<0.001). In the subgroup of BCT without RT there were significant differences in IL-RFS between histopathological subgroups: ng 1 + 2 (non-high grade) vs ng 3 (high grade; P=0.014), non-high-grade without comedo-type necrosis vs non-high-grade with comedo-type necrosis vs high-grade (the Van Nuys classification system; P=0.025). Growth pattern (not diffuse vs diffuse) and margins (free vs involved or not evaluated) showed a tendency (P=0.07 and 0.05, respectively) to be associated to IL-RFS. In contrast, no significant differences in IL-RFS were found in subgroups based on mode of detection, focality or size. Ninety-four per cent of the local recurrences after BCT appeared at the previous operation site.

CONCLUSIONS

In the BCT without RT group, combinations of either non-high grade and not a diffuse growth pattern or non-high grade and free margins identified groups (constituting approximately 30% of the patients) were at low risk of developing ipsilateral recurrences (6-10%), compared to a 31-37% recurrence risk in the remaining groups during the observed follow-up time. The beneficial effect of post-operative RT for these low-risk groups can be questioned, and should be studied further.

The cytoplasmic tyrosines of integrin subunit beta1 are involved in focal adhesion kinase activation

We have previously shown that mutation of the two tyrosines in the cytoplasmic domain of integrin subunit beta1 (Y783 and Y795) to phenylalanines markedly reduces the capability of beta1A integrins to mediate directed cell migration. In this study, beta1-dependent cell spreading was found to be delayed in GD25 cells expressing beta1A(Y783/795F) compared to that in wild-type GD25-beta1A. Focal adhesion kinase (FAK) tyrosine phosphorylation and activation were severely impaired in response to beta1-dependent adhesion in GD25-beta1A(Y783/795F) cells compared to that in wild-type GD25-beta1A or mutants in which only a single tyrosine was altered (beta1A(Y783F) or beta1A(Y795F)). Phosphorylation site-specific antibodies selective for FAK phosphotyrosine 397 indicated that the defect in FAK phosphorylation via beta1A(Y783/795F) lies at the level of the initial autophosphorylation step. Indeed, beta1A-dependent tyrosine phosphorylation of tensin and paxillin was lost in the beta1A(Y783/795F) cells, consistent with the impairment in FAK activation. In contrast, p130(CAS) overall tyrosine phosphorylation was unaffected by the beta1 mutations. Despite the defect in beta1-mediated FAK activation, FAK was still localized to focal adhesions. Taken together, the phenotype of the GD25-beta1A(Y783/795F) cells resembles, but is distinct from, the phenotype observed in FAK-null cells. These observations argue that tyrosines 783 and 795 within the cytoplasmic tail of integrin subunit beta1A are critical mediators of FAK activation and cell spreading in GD25 cells.

[Fiberoptic endoscopy confirms the cause of upper respiratory obstruction in small children. The most common causes to referrals are sleep apnea syndrome and inspiratory stridor]

Guidelines for the clinical investigation of young children with stridor and sleep apnea are presented. Clinical examination and flexible videolaryngoscopy performed in local anaesthesia are the most important diagnostic tools for this group of children. If the impairment is severe or an objective evaluation is needed the child should also undergo nocturnal polygraphic recording and lung function tests. Out of 43 children examined with flexible videolaryngoscopy 21 had positive findings, laryngomalacia being the most common diagnosis. Flexible videolaryngoscopy is a good complement to laryngoscopy under general anaesthesia. It can be performed as early as in the neonatal period.

Effects of tobacco smoke on tumor growth and radiation response of dunning R3327 prostate adenocarcinoma in rats

BACKGROUND

The influence of tobacco smoke has been investigated on the growth rate and histology of prostate cancer, both in untreated tumors and in those subjected to fractionated irradiation.

METHODS

Twenty-five rats were implanted bilaterally with Dunning R3327 tumor fragments at 10 weeks of age. Approximately 3 months later, they were randomly allocated to two groups, one of which was exposed to tobacco smoke for an hour each day, 5 days a week. Three weeks later the groups were further subdivided into two groups which acted as controls or were subjected to 5 daily doses of 6 Gy. The tumors were measured weekly to construct growth curves. At a fixed time, 9 weeks or 20 weeks later, the animals were sacrificed and the tumors were removed for histological evaluation of the tissue composition. Sections from each tumor were scored in a morphometric analysis of the fraction of the area of tumor that was occupied by (epithelial) tumor cells, by stroma, or by luminal spaces. In addition, the density of mast cells was assessed in adjacent sections stained with toluidine blue.

RESULTS

Smoking caused only minor changes in the growth rates of both the control and the irradiated tumors. At the cellular level, smoking caused a small but significant increase in the fraction of tumor cells relative to controls. Irradiation also caused a small but significant decrease in tumor cell fraction compared to controls, even after 20 weeks of regrowth. This difference was reduced in the smoking and irradiation group. The main difference observed was in the mast cell numbers. Smoking caused a 4-fold increase in mast-cell density. Irradiation caused an even greater increase (25-fold). The combination of smoking and irradiation resulted in an intermediate increase (10-fold).

CONCLUSIONS

Long-term smoke exposure can slightly alter the growth rate and morphology of Dunning R3327 rat prostatic adenocarcinoma, but our study does not show a negative effect on the outcome of radiation treatment of this tumor model. We have also demonstrated a highly elevated number of mast cells in the irradiated group, and have shown that smoke exposure significantly depressed the radiation-induced enhancement of the number of mast cells.

Detection of colorectal tumor and inflammatory bowel disease during follow-up of patients with initial diagnosis of irritable bowel syndrome

BACKGROUND

We wanted to estimate the incidence of irritable bowel syndrome (IBS) and functional dyspepsia (FD) in the general population, and the detection of colorectal tumor (CRT) and inflammatory bowel disease (IBD) after the diagnosis of IBS and FD.

METHODS

Patients aged 20-79 years newly diagnosed with IBS (N = 2956) or FD (N = 9900), together with a comparison cohort randomly sampled from the general source population, were followed-up during a mean time of 3 years.

RESULTS

We found an overall incidence of 10.3 per 1000 person-years for FD and 2.6 per 1000 person-years for IBS. There was a greater prevalence of depression, stress, fatigue, and pain disorders among IBS and FD patients than in the general population. During the 1st year after a diagnosis of IBS the cumulative risk of detecting CRT was close to 1% in IBS patients. After the 1st year the risk of CRT in IBS patients was close to that in the general population. We found a significantly increased risk of detecting IBD among patients initially diagnosed as having IBS (relative risk (RR), 16.3; 95% confidence interval (CI), 6.6-40.7), which was constant during all the follow-up period. No association was found between dyspepsia and CRT, or IBD.

CONCLUSION

IBS and FD shared some comorbidity features, yet demographics and incidence rates were different. Unlike the detection of colorectal tumor, the excess risk of IBD after an initial diagnosis of IBS was cumulatively increased during all the follow-up period. The continuously increased risk of IBD detection in IBS patients favors a true association between IBS and IBD.

Calcaneal ultrasound measurements are determined by age and physical activity. Studies in two Swedish random population samples

AIM

To present reference values and correlations with body composition, blood variables and lifestyle factors.

SUBJECTS

Two random population samples from Göteborg, Sweden, one comprising 184 men and 455 women aged 25-64 years (MONICA) and the other 860 women aged 55-82 years (BEDA) were studied.

METHODS

Calcaneal ultrasound measurement (LUNAR Achilles) and bioimpedance were measured. Smoking habits, coffee consumption, physical activity, psychological stress, education and marital status, as well as blood lipids, blood pressure, and fractures were studied.

RESULTS

Broadband ultrasound attenuation and stiffness were higher in men than in women (P < 0. 001), but speed of sound did not differ between sexes. Speed of sound, broadband ultrasound attenuation and stiffness decreased with age (P < 0.001). In both sexes speed of sound, broadband ultrasound attenuation and stiffness correlated positively to body size variables, and negatively with smoking in women after adjustment for age. Speed of sound, broadband ultrasound attenuation and stiffness were positively related to physical activity in both sexes, and these relationships were the only ones that remained in multivariate analyses in addition to age (negative). Osteoporotic fractures increased with age. Speed of sound, broadband ultrasound attenuation and stiffness were lower amongst women with osteoporotic fractures.

CONCLUSION

Speed of sound, broadband ultrasound attenuation and stiffness decreased with age and increased with physical activity, but body weight and height were not correlated in multivariate analyses. Osteoporotic fractures increased with age and were associated with lower calcaneal ultrasound values.

Overall mortality among patients surviving an episode of peptic ulcer bleeding

STUDY OBJECTIVE

The authors investigated whether patients who have survived an acute episode of peptic ulcer bleeding (PUB) have an excess long term all cause mortality compared with the general population free of PUB.

DESIGN

Follow up study of previously identified cohort of patients with a PUB episode and a general population cohort.

SETTING

The source population included all people aged 30 to 89 years, registered with general practitioners in the United Kingdom.

PATIENTS

All patients alive one month after the PUB episode constituted the cohort of PUB patients (n = 978). A control group of 5000 people was randomly sampled from the source population. The same eligibility criteria as for patients with PUB were applied to the control series. Also, controls had to be free of PUB before start date.

MAIN RESULTS

Relative risk of mortality among PUB patients was 2.1, 95% CI: 1.7, 2.6) compared with the general population. This increased mortality risk occurred mainly in the patients less than 60 years old. No difference was observed between men and women. The excess mortality was not only circumscribed to deaths attributable to recurrent gastrointestinal bleed, but also cardiovascular, cancer and other causes.

CONCLUSIONS

People who have survived an acute episode of PUB have a reduced long term survival compared with the general population. This reduction was stronger among middle age patients than in the elderly.

Expression of integrin subunit beta1B in integrin beta1-deficient GD25 cells does not interfere with alphaVbeta3 functions

We have expressed the beta1B integrin subunit in beta1-deficient GD25 cells to examine beta1B functions without the interference of endogenous beta1A expression. As previously reported [Retta et al., 1998, Mol. Biol. Cell 9, 715-731], the beta1B integrins did not mediate cell adhesion under normal culture conditions, while the presence of 0.3 mM Mn(2+) allowed beta1B integrins to support adhesion. Mn(2+), as well as the small soluble peptide GRGDS, induced a beta1B conformation, which was recognized by the mAb 9EG7, a marker for active or ligand-bound integrins. beta1B integrins were found to localize to a subset of focal contacts in a ligand-independent manner on fibronectin, but not on vitronectin. However, clustering of beta1B did not induce tyrosine phosphorylation of FAK, p130(Cas), or paxillin, as studied by beta1B-mediated adhesion, to fibronectin in the presence of Mn(2+) or to anti-beta1 antibody in DMEM. Induction of ligand-occupied conformation by the GRGDS peptide during the adhesion to anti-beta1 antibody also failed to trigger FAK phosphorylation. Stimulation of tyrosine phosphorylation on FAK, p130(Cas), and paxillin by adhesion via integrin alphaVbeta3 to fibronectin or vitronectin was not disturbed in GD25-beta1B cells compared to the untransfected GD25 cells, nor were any negative effects of beta1B observed on alphaVbeta3-mediated cell attachment, spreading, and actin organization, or on the cell proliferation rate. These results show that the reported negative effects of beta1B on adhesive events do not apply to alphaVbeta3-dependent interactions and suggest that they may specifically act on beta1 integrins.

Determination of the border between the transmembrane and cytoplasmic domains of human integrin subunits

In this study we have determined the position of the C-terminal end of the transmembrane domains of human integrin subunits (alpha2, alpha5, beta1, beta2) in microsomal membranes using the glycosylation mapping technique. In contrast to the common view, the transmembrane helices were found to extend roughly to Phe(1129) in alpha2, to Phe(1026) in alpha5, to Ile(757) in beta1, and to His(728) in beta2. The alpha-carbon of the conserved lysine present near the C-terminal end of the transmembrane helix (Lys(1125) in alpha2, Lys(1022) in alpha5, Lys(752) in beta1, and Lys(724) in beta2) is buried in the plasma membrane, and the charged amino group most likely reaches into the polar head-group region of the lipid bilayer. A possible role for the conserved lysine in integrin function is discussed.

Integrin subunits (beta)1C-1 and (beta)1C-2 expressed in GD25T cells are retained and degraded intracellularly rather than localised to the cell surface

We have previously identified the integrin (beta)1C-2 and characterised the distribution of (beta)1C-1 and (beta)1C-2 transcripts in various cell lines and normal cells. In this study we have investigated the expression of the two (beta)1C-variants in integrin (beta)1 deficient mouse GD25T cells. After stable transfection of the GD25T cells with cDNAs coding for (beta)1A, (beta)1C-1 and (beta)1C-2, the cell surface expression of the (beta)1C-1 and (beta)1C-2 variants was found to be very low while the (beta)1A variant was expressed at high levels. Northern blot analysis showed that the level of (beta)1-transcript in the (beta)1C-1 and (beta)1C-2 clones was equal or higher than in the (beta)1A clones. Metabolic labelling and deglycosylation by endoglycosidase H treatment clearly demonstrated that the majority of the (beta)1C-1 and (beta)1C-2 chains did not become maturely glycosylated, nor did they dimerize with (alpha) subunits. After 20 hours of chase, the labelled (beta)1C-1 and (beta)1C-2 chains had been gradually degraded, whereas immature (beta)1A was converted into the maturely glycosylated form during the same period of time. Immunostaining showed intracellular (beta)1 localisation in the (beta)1C-1 and (beta)1C-2 expressing clones, while in the (beta)1A expressing clones the (beta)1 chains were mainly localised to focal adhesion sites and along fibronectin fibres. Taken together, we have shown that expression of both integrin (beta)1C-1 and (beta)1C-2 in GD25T cells result in very low cell surface expression compared with the normal (beta)1A isoform. Instead, both (beta)1C-1 and (beta)1C-2 chains remain in the endoplasmic reticulum until they are intracellularly degraded.

Health resource utilization and drug treatment pattern in a cohort of patients with a first episode of gastroesophageal reflux disease

PURPOSE

To describe the demographics, comorbidity, and health care resource utilization, as well as treatment patterns among gastroesophageal reflux disease (GORD) patients.

METHODS

We identified a population-based cohort of newly diagnosed GORD patients receiving cimetidine, ranitidine or omeprazole. Our final study population consisted of 1193 patients, who were followed up for 1 year.

RESULTS

Mild symptoms were reported in 44% of cases, moderate in 52%, and 4% had a severe episode. Moderate and severe cases were more likely to undergo endoscopy and to be hospitalized for GORD than mild cases. They also had a higher probability of receiving long-term continuous treatment and to start initial treatment with omeprazole rather than with cimetidine or ranitidine. Initial treatment failure was greater among severe cases and in patients started on H(2)-blockers.

CONCLUSION

This study has shown that severity of initial GORD episode is significantly associated with an increased use of health resources, and is the major determinant of initial treatment failure. Patients started on H(2)-blockers also had a greater risk of initial treatment failure compared to patients started on omeprazole.

Characterization of a hyaluronan receptor on rat sinusoidal liver endothelial cells and its functional relationship to scavenger receptors

Hyaluronan is a widely distributed extracellular component of connective tissue with several mechanical and cell biological functions. The serum level of hyaluronan is elevated in rheumatic and liver diseases and in certain malignancies. The major route of hyaluronan clearance from the blood is via the liver, taken up predominantly by sinusoidal liver endothelial cells. We have purified a novel hyaluronan binding protein from liver that also has an affinity for the N-terminal propeptide of type I procollagen, a physiological scavenger receptor ligand. A polyclonal antibody raised against the protein was found to inhibit the binding and degradation of hyaluronan as well as two scavenger receptor ligands by cultured sinusoidal liver endothelial cells. Immunostaining of nonpermeabilized liver cells and liver sections showed that the antibody specifically stains the surface of sinusoidal liver endothelial cells. After pretreatment with monensin to block the recirculation of endocytic receptors, the immunostaining was specifically associated with early endosomes of these cells. Thus, this rat sinusoidal liver endothelial cell hyaluronan receptor shares functional properties with the scavenger receptor family, a group of proteins shown to play a key role in the uptake of atherogenic lipids and other waste products from the tissues.

The CrescoTi Precision method: description of a simplified method to fabricate titanium superstructures with passive fit to osseointegrated implants

Casting distortion and inadequate handling in the dental laboratory are 2 factors that can cause misfit between a cast framework and the implant analogs in the master cast. This article describes the CrescoTi Precision procedure, which has been developed for correction of misfit between cast titanium frameworks and supporting dental implants. The simplicity and accuracy of the procedure appear to demonstrate technical progress toward obtaining optimal precision of fit of the superstructure components, thereby eliminating stress forces that may be transformed to the peri-implant bone.

Changes in airway dead space in response to methacholine provocation in normal subjects

Measurements of bronchial hyper-responsiveness rely on sensitive techniques for measurement of bronchoconstriction, ideally based on tidal breathing. A potentially useful technique is measurement of airway dead space (VDaw), which reflects the volume of the conducting airways. The aim of this study was to evaluate measurements of VDaw with the single breath test for CO2 (SBT-CO2), compared to spirometric measurements, as a method of measuring bronchial response to methacholine challenge. Nineteen healthy adults were studied. Dosimetric methacholine challenge tests were performed on two study days. Forced expirations or the SBT-CO2 were used to assess the response. There were dose-dependent reductions in the spirometric measurements, with a 10 +/- 10% reduction from the baseline value of forced expiratory volume at the highest dose of methacholine. There was a dose-dependent reduction from the baseline value of VDaw by 19 +/- 9% at the highest dose. There was also a dose-dependent increase in the slope of the alveolar plateau of the SBT-CO2. This study provides support for measurement of VDaw as a means of evaluating bronchial responsiveness after methacholine challenge. In a group of healthy adults, this method shows a greater response but with similar dispersion as measurement of forced expiratory volume after methacholine challenge.

Signal transduction-mediated adherence and entry of Helicobacter pylori into cultured cells

BACKGROUND & AIMS

An ability to invade host cells could be a means for Helicobacter pylori to achieve resistance to antibiotic therapy. The aim of this study was to investigate the mechanisms involved in adherence and entry of H. pylori into cultured cells.

METHODS

Coinfection with Yersinia expressing mutant or wild-type YopH tyrosine phosphatase was used. Genistein and cytochalasin D were used as inhibitors of adherence and entry; entry was monitored by a gentamicin-protection assay. Target cells were AGS cells and a beta1-integrin-deficient cell line with its corresponding beta1-integrin-expressing transfectant.

RESULTS

H. pylori induced phosphorylation of 125-130-kilodalton proteins, similar in size to the target proteins of Yersinia YopH. Adherence of H. pylori was inhibited by Yersinia organisms expressing enzymatically active YopH but not by inactive YopH. Adherence and entry of H. pylori was considerably higher with beta1-integrin-transfected cells than with beta1-integrin-deficient cells. Antibodies directed against alpha5- and beta1-integrin chains reduced adherence to the alpha5beta1-integrin-expressing gastric cell line AGS. Entry was inhibited by both cytochalasin D and genistein. Entry, but not adherence, was higher for 2 type I strains than for a type II isolate.

CONCLUSIONS

Invasion of gastric epithelium via an integrin-mediated pathway could contribute to the ability of H. pylori to establish persistent infection.

Use of cimetidine, omeprazole, and ranitidine in pregnant women and pregnancy outcomes

Evidence documenting the safety of acid-suppressing drugs in pregnancy is very limited. The authors assessed the prevalence of congenital malformations in first trimester-exposed pregnancies to cimetidine, omeprazole, and ranitidine and compared it with nonexposed pregnancies between 1991 and 1996. Two different sources were used, the United Kingdom General Practice Research Database and the Italian Friuli-Venezia Giulia Health Database. The final study cohort included 1,179 pregnancies from the United Kingdom and 1,057 from Italy. Abortions or ectopic pregnancies were not included. There were 20 stillbirths and 2,261 live-born babies in both cohorts combined, with 100 offspring identified with a malformation. The overall malformation rate was 4.4%. The relative risks for nongenetic congenital malformations associated with the use of cimetidine, omeprazole, and ranitidine were 1.2 (95% confidence interval (CI): 0.6, 2.3), 0.9 (95% CI: 0.3, 2.2), and 1.4 (95% CI: 0.8, 2.4), respectively, compared with the nonexposed. No specific grouping in the distribution of malformations was observed in any of the three exposed groups. Moreover, no relation was found between drug exposure and preterm delivery or growth retardation. These findings suggest that the use of acid-suppressing drugs during the first trimester of pregnancy is not associated with a major teratogenic risk.

One-year follow-up of newly diagnosed irritable bowel syndrome patients

BACKGROUND

Irritable bowel syndrome is the most common functional gastrointestinal disorder seen by general physicians.

METHODS

We followed up a population-based cohort of newly diagnosed irritable bowel syndrome patients aged 20-79 years, to examine patterns of treatment, comorbidity and healthcare utilization. We used the UK General Practice Research Database as the source population. Individuals with other gastrointestinal diseases, cancer and pregnant women were not included. There were 2956 patients in our final cohort.

RESULTS

Irritable bowel syndrome patients were mainly young and middle-aged; only 12% were 60 years or older. The majority of patients were women (74%). There were no marked differences in terms of use of healthcare services or comorbidity status in the year before irritable bowel syndrome diagnosis as compared to the year after. Fourteen per cent of irritable bowel syndrome patients received no drug treatment at all. Among those treated, the first choice was an antispasmodic. Elderly patients (>60 years old) were more likely to receive drug treatment. Females had a slightly higher probability of being treated than men, except for the category of anti-diarrhoeal drugs.

CONCLUSION

This study has shown that irritable bowel syndrome patients are mainly young and female. We also found that treatment pattern varied according to age and gender. Elderly patients and females were at a higher risk of receiving drug treatment.