Suppression of tumorigenic and metastatic potentials of human melanoma cell lines by mutated (143 Val-Ala) p53

Metastatic melanoma, compared with other cancers, appears to be unusual because of its low frequency of p53 mutations and prevalence of wild-type p53 protein in advanced malignancy. Here, we examined the effects of wild-type and mutated p53 (143 Val-Ala) on tumorigenic and metastatic potential of two human melanoma cell lines. The cell line UISO-MEL-4 contains wild-type p53 and is tumorigenic, whereas UISO-MEL-6 lacks p53 and produces lung and liver metastasis upon s.c. injection into athymic mice. Our study showed that UISO-MEL-4 stably transfected with wild-type p53 cDNA driven by cytomegalovirus promoter-enhancer sequences expressed high levels of p53 and p21 and formed s.c. tumours in vivo. Mutated p53 (143 Val-Ala) expression, on the other hand, inhibited tumour growth in 50% of cases and produced significantly slower growing non-metastatic tumours. Reduced tumour growth involved necrotic as well as apoptotic cell death. Inhibition of tumour growth was abrogated by the addition of Matrigel (15 mg ml(-1)). With UISO-MEL-6 cells, stably transfected with mutant p53, tumour growth was delayed and metastasis was inhibited. In soft agar colony formation assay, both wild-type and mutant p53 transfectants reduced anchorage-independent colony formation in vitro. These data suggest that mutated (143 Val-Ala) p53, which retains DNA binding and some of the transactivation functions of the wild-type p53 protein, suppresses tumorigenic and metastatic potentials of human melanoma cell lines in vivo.

Systemic lupus erythematosus in Denmark: clinical and epidemiological characterization of a county-based cohort

A population based cohort of patients with systemic lupus erythematosus (SLE) was recruited from a for epidemiological purposes representative Danish region. Patients were ascertained from 4 different sources with a high degree of completeness as estimated by using capture-recapture analysis. The diagnosis was verified by means of case records, patient interviews, and clinical examinations. Patients were classified according to the 1982 revised ACR criteria as Definite SLE (D-SLE) fulfilling > or = 4 criteria and Incomplete SLE (I-SLE) with < 4 criteria. As of January 1, 1995, the point prevalences of D-SLE and I-SLE were 21.7 and 5.2 per 100000 respectively. The cohort comprised 98% white Europeans. The annual incidence of D-SLE increased from 1.0/100,000 to 3.6/100,000 during the study period 1980-94. D-SLE patients had clinical profiles comparable to other Western European study populations. The I-SLE subclass had milder disease manifested by lower criterial load and absence of cerebral and kidney involvement. Tissue and organ damage expressed as SLICC-score increased in the order of live I-SLE, live D-SLE, and deceased patients.

Identification of non-heme diiron proteins that catalyze triple bond and epoxy group formation

Acetylenic bonds are present in more than 600 naturally occurring compounds. Plant enzymes that catalyze the formation of the Delta12 acetylenic bond in 9-octadecen-12-ynoic acid and the Delta12 epoxy group in 12,13-epoxy-9-octadecenoic acid were characterized, and two genes, similar in sequence, were cloned. When these complementary DNAs were expressed in Arabidopsis thaliana, the content of acetylenic or epoxidated fatty acids in the seeds increased from 0 to 25 or 15 percent, respectively. Both enzymes have characteristics similar to the membrane proteins containing non-heme iron that have histidine-rich motifs.

Current concepts of shoulder arthroplasty

Shoulder arthroplasty is an accepted treatment for certain proximal humerus fractures and for glenohumeral arthritis. The indications for shoulder arthroplasty are fairly well defined and the outcomes are predictable and highly successful. However, it is a technically demanding surgical procedure, with which few orthopaedic surgeons gain much experience. Most of the currently available implant systems are modifications of the original unconstrained components that were introduced by Neer. Current issues of controversy include implant modularity, glenohumeral mismatch, implant fixation, and the role of glenoid replacement in outcome.

A comparison of disease and gene frequencies of inborn errors of metabolism among different ethnic groups in the West Midlands, UK

OBJECTIVE

To assess birth and gene frequencies of specific autosomal recessively inborn errors of metabolism (IEM) within different ethnic groups.

DESIGN

Retrospective study in a regional centre for investigation and treatment of IEM.

SUBJECTS

All children born within the West Midlands NHS Region, UK, during the decade immediately preceding the 1991 National Census.

METHODS

Birth frequencies for individual IEM were calculated separately for the main ethnic groups in the West Midlands using data from the West Midlands Neonatal Screening Programme, the regional register of IEM patients, and population frequencies from the National Census. Gene frequencies were calculated using previously documented observations on parental consanguinity rates and inbreeding coefficients.

RESULTS

The overall incidence of recorded IEM was tenfold higher among Pakistanis compared to white children (1:318 v 1:3760), whereas only one AfroCaribbean child was identified (incidence 1:16 887). Tyrosinaemia type 1, cystinosis, mucopolysaccharidosis type 1, non-ketotic hyperglycinaemia, and hyperchylomicronaemia all occurred more frequently among Pakistanis. An increased gene frequency was only confirmed for tyrosinaemia. The incidence of phenylketonuria was similar in Pakistani and white children (1:14 452 v 1:12 611), but the gene frequency was significantly lower in Pakistanis (1:713 v 1:112). These results illustrate the interplay between gene frequency and parental consanguinity in determining disease frequencies in different populations, and indicate anticipated disease frequencies in the absence of consanguineous marriage. These figures have implications for the organisation of services for management of inborn errors, for genetic counselling, and for the assessment of gene flow in world populations.

Alterations in colonic mucosal vessels in patients with cirrhosis and noncirrhotic portal hypertension

Changes in intestinal mucosal microvasculature as a cause of lower gastrointestinal hemorrhage in patients with portal hypertension have been well documented clinically, but the analogous histomorphological changes have not been well characterized. The goal of this study was to evaluate qualitative and quantitative changes in colonic mucosal vessels in patients with cirrhosis or clinically evident portal hypertension and to correlate these changes with endoscopic and clinical findings. Colon biopsy or resection specimen slides from 46 patients with biopsy-proven cirrhosis (44 patients) or noncirrhotic portal hypertension (two patients) were reviewed. Immunoperoxidase stain for CD34 antigen was used to facilitate visualization of mucosal vessels, and vessel diameter was measured with a micrometer. Patients with inflammatory bowel disease were excluded. Twenty-four normal colon biopsy specimens served as controls. Mucosal vessels were divided into superficial, intermediate, and deep layers. As a group, the cirrhotic patients had a significantly higher mean diameter of vessels in all three layers. Qualitatively, increased numbers of small vessels and prominent branching were noted, especially in the superficial and intermediate layers. Tortuous, thick-walled vessels, suggesting arterialization of venules, were present in some cases. Eleven patients had endoscopic findings suggestive of vascular abnormalities, including erythematous mucosal patches, red macules, and telangiectasias. Eighteen had esophageal varices, and five had portal gastropathy. Nineteen patients had gastrointestinal (GI) bleeding, localized to the lower GI tract in 11. These qualitative and quantitative findings suggest that colonic mucosal vascular lesions are common in portal hypertension and may represent a potential source of clinically significant lower GI hemorrhage in these patients.

The shady side of solar protection

OBJECTIVE

To determine the value of shade in protecting humans from solar ultraviolet (UV) radiation.

DESIGN AND SETTING

Measurement with photometers of protection factors for ultraviolet B radiation (UVB) and for total solar radiation for different types of trees and other structures during the summer months (1995-1997) in south-east Queensland. (The protection ratio is the ratio of the intensity of UVB or total solar radiation in direct sunlight to that in shade.)

RESULTS

For summer sun at midday, the mean (SD) UV protection ratio for the shade of trees (n = 65) was 4.21 (1.36) on a horizontal surface and 1.33 (0.30) on a vertical surface. In contrast, the mean (SD) protection ratio for total solar energy (primarily infrared) was much higher (12.1 [1.4]). Trees common in recreational areas in Australia (eucalypts: UV protection ratio, 3.52 [0.79]; Norfolk Island pines: UV protection ratio, 3.72 [0.98]) offered reduced protection compared with trees with more dense foliage (UV protection ratio, 5.48 [1.44]). Over a whole day, measurement of shade by trees and other structures showed that the UV protection ratio was lower in the morning and afternoon. Shade from awnings, buildings and hats gave similar results to those for trees. Both at midday and over a whole day satisfactory protection (UV protection ratio > 15) was obtained only in shade which eliminated exposure to the sky as well as to direct sunlight; for example, in thickly wooded areas and under low, widely overhanging structures.

CONCLUSIONS

Most forms of shade, while useful, offer people insufficient protection from solar UV. A fair-skinned person sheltering under a tree could suffer sunburn after less than one hour. There is a need for appropriate design of structural shade, use of other solar protection measures in conjunction with shade, and research on behavioural responses to shade.

Comparative pupil dilation using phenylephrine alone or in combination with tropicamide

OBJECTIVE

A prevalence survey of actinic and other eye diseases was conducted in Nambour, Queensland, Australia, in 1992. Pupils were dilated with phenylephrine alone for cataract identification because there were concerns that patient discomfort, due to cycloplegia occurring with the usual dilating agents of tropicamide and phenylephrine, may influence future compliance in an associated intervention study. This validation study was undertaken to measure the possible underestimation of cataract prevalence in this community study, which may have occurred because of inadequate dilation from phenylephrine alone.

DESIGN

The study design was a repeated measures experimental design.

PARTICIPANTS

Forty-seven normal subjects participated in the study. Both eyes were tested.

INTERVENTION

Pupil diameter after dilation with three drops of 10% phenylephrine alone was compared with pupil diameter after dilation with three drops of 10% phenylephrine together with three drops of 1% tropicamide. The two regimens were given to the same subjects 1 week apart. Reversal was attempted with thymoxamine hydrochloride 0.5%.

MAIN OUTCOME MEASURES

Pupil diameter was assessed using a Neitz cataract camera, and accommodation reserve also was measured. Subjects' subjective appreciation of return of ocular function was assessed by a questionnaire. Repeated measures analysis of variance, paired t test, McNemar's test, and Wilcoxon signed rank test were used to analyze outcomes.

RESULTS

Mean maximum pupil size with 10% phenylephrine and 1% tropicamide was significantly larger than pupil size after the use of 10% phenylephrine alone (F1,19 = 18.99, P = 0.0003). However, there was no significant difference between the two dilation regimens when comparing the proportion of subjects who dilated to 6 mm or more (McNemar's X(2)1 = 2.7, P > 0.1). Compared with 10% phenylephrine and 1% tropicamide, pupil diameters were significantly smaller (t46 = 16.77, P = 0.0001), and accommodation reserve greater (t46 = 4.14, P = 0.0001), 40 minutes after reversal with thymoxamine in the group dilated with 10% phenylephrine alone.

CONCLUSION

Pupil dilation with 10% phenylephrine alone, if allowed at least 40 minutes to act, will be as satisfactory for the identification of cataracts in a normal population as 10% phenylephrine and 1% tropicamide and is more acceptable because of reduced problems with glare and accommodation.

Neonatal screening for inborn errors of metabolism: cost, yield and outcome

OBJECTIVES. To systematically review the literature on inborn errors of metabolism, neonatal screening technology and screening programmes in order to analyse the costs and benefits of introducing screening based on tandem mass-spectrometry (tandem MS) for a wide range of disorders of amino acid and organic acid metabolism in the UK. To evaluate screening for cystic fibrosis, Duchenne muscular dystrophy and other disorders which are tested on an individual basis. HOW THE RESEARCH WAS CONDUCTED. Systematic searches were carried out of the literature on inborn errors of metabolism, neonatal screening programmes, tandem MS-based neonatal screening technology, economic evaluations of neonatal screening programmes and psychological aspects of neonatal screening. Background material on the biology of inherited metabolic disease, the basic philosophy, and the history and current status of the UK screening programme was also collected. Relevant papers in the grey literature and recent publications were identified by hand-searching. Each paper was graded. For each disease an aggregate grade for the state of knowledge in six key areas was awarded. Additional data were prospectively collected on activity and costs in UK neonatal screening laboratories, and expert clinical opinion on current treatment modalities and outcomes. These data were used to construct a decision-analysis model of neonatal screening technologies, comparing tandem MS with the existing phenylketonuria screening methods. This model determined the cost per additional case identified and, for each disease, the additional treatment costs per case, and the cost per life-year saved. All costs and benefits were discounted at 6% per annum. One-way sensitivity analysis was performed showing the effect of varying the discount rate, the incidence rate of each disorder, the number of neonates screened and the cost of tandem MS, on the cost per life-year gained. RESEARCH FINDINGS. The UK screening programmes for phenylketonuria and congenital hypothyroidism have largely achieved the expected objectives and are cost-effective. Current concerns are the difficulty of maintaining adequate coverage, perceived organisational weaknesses, and a lack of overview. For many of the organic acid disorders it was necessary to rely on data obtained from clinically-diagnosed cases. Many of these diseases can be treated very effectively and a sensitive screening test was available for most of the diseases. Except for cystic fibrosis, there have been no randomised controlled trials of the overall effectiveness of neonatal screening. Despite the anxiety generated by the screening process, there is strong parental support for screening. The effects of diagnosis through screening on subsequent reproductive behaviour is less clear. Conflicts exist between current concepts and the traditional principles of screening. The availability of effective treatment is not an absolute prerequisite: early diagnosis is of value to the family concerned and, to the extent that is leads to increased use of prenatal diagnosis, may help to reduce the overall burden of disease. Neonatal screening is also of value in diseases which present early but with non-specific symptoms. Indeed, almost all of the diseases considered could merit neonatal screening. The majority of economic evaluations failed to incorporate the health benefits from screening, and therefore failed to address the value of the information which the screening programmes provided to parents. The marginal cost of changing from present technology to tandem MS would be approximately 0.60 pounds per baby at a workload of 100,000 samples a year, and 0.87 pounds at 50,000 samples per year. The ability to screen for a wider range of diseases would lead to the identification of some 20 additional cases per 100,000 infants screened, giving a laboratory cost per additional diagnosis of 3000 pounds at an annual workload of 100,000 babies per year.(ABSTRACT TRUNCATED)

Neonatal screening: current trends and quality control in the United Kingdom

Neonatal screening for phenylketonuria (PKU) and congenital hypothyroidism (CHT) is universal across the UK using heel prick blood collected at 6-14 days of age. Additional programmes for sickle cell disorders, cystic fibrosis, Duchenne muscular dystrophy and galactosaemia are provided in some areas. The number of inherited metabolic disorders (IMDs) has greatly increased since the introduction of PKU screening, and there have been major advances in treatment, e.g. organ transplantation, drug therapy. Recent developments in technology have expanded the possibilities for screening using the heel prick blood specimen, particularly the application of tandem mass spectrometry. There is a case for introducing tandem mass spectrometry, limited to clearly defined diseases where specificity is adequate and there are satisfactory diagnostic tests. Any change in newborn screening to a much broader group of disorders must be carefully introduced and monitored preferably as a pilot study. A key component of a laboratory screening service is quality control. There are well established UK programmes for PKU and CHT. Consideration of the needs for other disorders is now an important priority.

Inhibition of protein synthesis by nitric oxide correlates with cytostatic activity: nitric oxide induces phosphorylation of initiation factor eIF-2 alpha

BACKGROUND

Nitric oxide (NO) is cytostatic for proliferating cells, inhibits microbial growth, and down-regulates the synthesis of specific proteins. Studies were undertaken to determine the mechanism by which NO inhibits total protein synthesis and whether the inhibition correlates with established cytostatic activities of NO.

MATERIALS AND METHODS

In in vitro experiments, various cell types were exposed to NO using either donors or expression of inducible NO synthase (iNOS). The capacity of NO to suppress total protein synthesis, measured by incorporation of 35S-methionine into protein, was correlated with the capacity of NO to suppress cell proliferation, viral replication, or iNOS expression. Phosphorylation of eIF-2 alpha was examined as a possible mechanism for the suppressed protein synthesis by NO.

RESULTS

Both NO donors and expression of the iNOS suppressed total protein synthesis in L929 cells and A2008 human ovarian tumor cells in parallel with decreased cell proliferation. Suppressed protein synthesis was also shown to correlate with decreased vaccinia virus proliferation in murine peritoneal macrophages in an iNOS-dependent manner. Furthermore, iNOS expression in pancreatic islets or RAW264.7 cells almost completely inhibited total protein synthesis, suggesting that nonspecific inhibition of protein synthesis may be the mechanism by which NO inhibited the synthesis of specific proteins such as insulin or iNOS itself. This possibility was confirmed in RAW264.7 cells where the inhibition of total protein synthesis correlated with the decreased iNOS protein. The decrease in protein levels occurred without changes in iNOS mRNA levels, implicating an inhibition of translation. Mechanistic studies revealed that iNOS expression in RAW264.7 cells resulted in the phosphorylation of eIF-2 alpha and inhibition of the 80S ribosomal complex formation.

CONCLUSIONS

These results suggest that NO suppresses protein synthesis by stimulating the phosphorylation of eIF-2 alpha. Furthermore, our observations indicate that nonspecific inhibition of protein synthesis may be a generalized response of cells exposed to high levels of NO and that inhibition of protein synthesis may contribute to many of the described cytostatic actions of NO.

[Insulin-dependent diabetes in the county of Funen 1970-2020. An epidemiological description]

We present an epidemiological model applicable to insulin-dependent diabetes mellitus (IDDM), based on which prevalence rates are estimated from assumed rates of incidence and mortality of diabetes. The model is illustrated by analysing epidemiological data on IDDM in Fyn County, Denmark for the period 1970-1990, with predictions of prevalence rates during 1990-2020. The epidemiological model assumes known prevalence rates as well as incidence rates and mortality at a given point of time. Under assumed rates of incidence and mortality of IDDM and its complications, the prevalence rate is the dependent variable which is estimated as a function of calendar time. We used epidemiological data on IDDM (operationally defined as insulin-treated diabetes with onset before age 30 years), blindness and nephropathy as well as mortality as reported for the years 1973 and 1987 in Fyn County, Denmark. During 1970-1990 the prevalence of IDDM increased steadily, due to increasing incidence and decreasing risk of complications and mortality. The relative prevalence of patients with nephropathy increased whereas that of blind patients decreased considerably. Under specified assumptions regarding the future levels of incidence of disease, complications and of mortality, it is estimated that the prevalence rate of IDDM in the year 2020 will be 45-60% higher than the level in 1990. The relative prevalence of patients with nephropathy will increase further, whereas the relative prevalence of blind patients will remain constant at a low level. We conclude that IDDM will represent an increasing public health problem in Denmark over the next decades, with increasing overall prevalence rates and a rising proportion of patients with nephropathy. The major determinants of this trend are increasing incidence, combined with declining mortality and declining risk of complications. It is recommended that epidemiological modelling techniques be further developed to provide improved data for the planning of the future diabetes care.

History of tropical military service and risk of primary cutaneous melanoma in Queensland men

A population-based case-control study was undertaken to determine whether cutaneous melanoma is associated with past military service in tropical locations. The participants were 150 male residents of southern Queensland aged 50 or over with a first diagnosis of cutaneous melanoma notified to the Queensland Cancer Registry between 1 July 1993 and 30 June 1994; 150 age-matched controls were randomly selected from the Queensland electoral roll. Data were collected from participants using a structured questionnaire. Overall, 82 (55%) cases and 80 (53%) controls reported a period of military service. Of these, 42% of both cases and controls spent part of their military service in tropical locations, with little difference in the distribution of duration of tropical service between the two groups. Compared with those who had no tropical military service, the risk of melanoma among those who had served more than 3 years in the tropics was 0.9 (0.3-2.7). Against a background level of very high risk of melanoma among Queensland men, there was no evidence that tropical military service materially increased the risk.

Hematopoietic cytokine-mediated FDG uptake simulates the appearance of diffuse metastatic disease on whole-body PET imaging

FDG-PET is increasingly being used to assess malignant tumors. However, leukocyte colony-stimulating factors (CSFs), which promote the expansion of hematopoietic bone marrow, have also been demonstrated to cause increased bone-marrow FDG uptake. Three hundred FDG-PET studies conducted over a 1-year period were reviewed for diffuse bone-marrow uptake. Elevated bone-marrow uptake on PET was correlated with pathological findings and courses of granulocyte-CSF (G-CSF) therapy. These results demonstrate that G-CSF mediated FDG uptake in bone marrow is often indistinguishable from that caused by disseminated metastatic disease. However, the bone-marrow response to G-CSF decreases rapidly following the last CSF administration. Therefore, FDG-PET in patients receiving G-CSF should be delayed, when possible, until 5 days after the end of G-CSF therapy.

Relationship of endogenous sex hormones to lipids and blood pressure in mid-aged women

PURPOSE

The relationship between endogenous sex hormones and blood lipids was examined in a representative sample of 438 Australian-born women 45 to 56 years of age taking part in a longitudinal study of the menopausal transition. Data from 363 women who were taking neither exogenous hormones nor lipid-altering medications, were not diabetic, and who had provided blood samples were available for analysis.

METHODS

Multiple linear regression was used to examine the relationship between sex hormones and high density lipoprotein cholesterol (HDL), low density lipoprotein cholesterol (LDL), triglycerides, and diastolic blood pressure (DBP), taking account of the effects of age, body mass index (BMI), smoking, alcohol intake, and exercise.

RESULTS

There was no significant relationship between estradiol and HDL, LDL, triglyceride, or DBP levels. Free androgen index was positively associated with LDL. However, BMI was an important predictor of all three lipid measures and DBP. HDL was positively associated with age and was highest among women with lowest BMI, high alcohol intake, and in nonsmokers. LDL increased with BMI, free androgen index, and age, but was lower amongst women who exercised more than two or three times per week. Triglyceride also increased with BMI, and was higher among smokers. DBP increased with BMI only.

CONCLUSIONS

The results do not support the view that endogenous sex hormones are strongly associated with cardiovascular risk factors around the time of menopause.

The intuition of the negative in Playing and reality

The author draws some parallels between his own conceptions on the work of the negative with some ideas presented by Winnicott in the ultimate version of his paper on 'Transitional objects and transitional phenomena'. He underlines the germs of the intuition of the negative in Winnicott's general theory ('not me possession', transitional object as not being the breast, the decathexis of the representation of the object). He then goes on to examine in detail the clinical material of a patient, in the last part of the paper, which has been published posthumously. In this last part the negative is mentioned explicitly and the idea is openly presented. We have here a concept of which Winnicott had the intuition without having the possibility of considering its full development and implications. It so happened that the patient whose clinical material is published in 'Playing and Reality' came to the author to continue her analytic experience. One can compare the material presented in these two analytical relationships. The author comments about his relationship with the patient and of the way she meets his own hypotheses.

Germline duplication of chromosome 2p and neuroblastoma

A child with a germline duplication of chromosome 2p, 46,XY,der(13)t(2;13)(p23;q34), who developed a fatal neuroblastoma confirmed at necropsy is reported. Fluorescent in situ hybridisation studies showed chromosome 2p (p23-pter) duplicated on chromosome 13 (q34). The clinical features of the present case shared many similarities to previous reports of trisomy 2p and there have been two cases described with neuroblastoma. Germline duplication of chromosome 2p including the N-myc proto-oncogene may have pre-disposed to the development of neuroblastoma in this case.

Diabetes insipidus from sarcoidosis confined to the posterior pituitary

A young white man with new-onset central diabetes insipidus was discovered to have a posterior pituitary mass on magnetic resonance imaging. No other radiological abnormalities were noted in the anterior pituitary, infundibulum or hypothalamus. No other endocrinopathies were present: laboratory investigations showed normal basal concentrations of anterior pituitary hormones, including prolactin. The patient was suspected to have sarcoidosis affecting the posterior pituitary, because of the discovery of pulmonary sarcoidosis during his diagnostic evaluation. His symptoms of polydipsia and polyuria responded promptly to intranasal administration of 1-desamino-8-D-arginine vasopressin (DDAVP). The patient demonstrated complete regression of the posterior pituitary mass after a course of corticosteroid therapy. However, his diabetes insipidus persisted and he continues to need DDAVP treatment, currently at 12 months of follow-up. The resolution of the neurohypophysial mass was compatible with the diagnosis of pituitary sarcoidosis and this precluded the need for a transsphenoidal biopsy or surgery.

A bioluminescent assay for agonist activity at potentially any G-protein-coupled receptor

Transient expression of apoaequorin in Chinese hamster ovary (CHO) cells and reconstitution with the co-factor coelenterazine resulted in a large, concentration-dependent agonist-mediated luminescent response following cotransfection with the endothelin ETA, angiotensin ATII, thyrotropin-releasing hormone (TRH), and neurokinin NK1 receptors, all of which interact pre-dominantly with the G alpha q-like phosphoinositidase-linked G-proteins. A substantially greater luminescence was obtained with mitochondrially targeted apoaequorin compared to cytoplasmically expressed apoaequorin. To generate a system amenable for the study of agonist activity at virtually any G-protein-coupled receptor the alpha subunit of the receptor promiscuous G-protein G alpha 16 was either transiently or stably expressed in CHO cells together with apoaequorin. In cells expressing G alpha 16, but not in its absence, agonists at a series of receptors which normally interact with either G alpha s or G alpha i were now able to cause a luminescent response from mitochondrially targeted apoaequorin. In the case of the A1 adenosine receptor, this response was clearly a result of activation of G alpha 16 and not a consequence of the release of the G alpha i-associated beta/gamma complex, as the luminescent response was unaffected by pertussis toxin treatment of the cells, whereas agonist-mediated inhibition of adenylyl cyclase activity was attenuated. These studies describe the use of coexpressed apoaequorin as a reporter for G-protein-coupled receptor-mediated calcium signaling. Furthermore, coexpression of G alpha 16 and apoaequorin provides a basis for a generic mammalian cell microplate assay for the assessment of agonist action at virtually any G-protein-coupled receptor, including orphan receptors for which the physiological signal transduction mechanism may be unknown.

Gastric graft-versus-host disease: a blinded histologic study

Acute graft-versus-host disease (GvHD) of the upper gastrointestinal (GI) tract is common after allogeneic bone marrow transplantation (BMT). However, diagnosis cannot be made on clinical presentation and endoscopic findings alone, because these are nonspecific, and histologic confirmation is often desirable. The diagnosis of gastric GvHD is often based on subtle findings with considerable potential for variability in interpretation. Evaluation of the reproducibility of diagnosis and recognition of histologic features of gastric GvHD was based on blinded review of 56 gastric biopsies (24 from patients with allogeneic BMT or unrelated umbilical cord blood transplantation and 32 control biopsies from patients who did not undergo BMT, of whom eight had active GI cytomegalovirus [CMV] infection). Histologic criteria for GvHD were apoptosis and gland destruction, sparse inflammatory infiltrate, and granular eosinophilic debris in dilated glands. Seventeen patients (22 biopsies) were judged to have clinical GvHD on the basis of skin or liver involvement and GI symptoms without other known cause. Eighteen of these 22 gastric biopsies were classified as GvHD by at least two of the three pathologists on initial review. Blinded histologic diagnosis of GvHD had a positive predictive value of 69%, a sensitivity of 82%, and specificity of 76%. False-positive results occurred in CMV gastritis, human immunodeficiency virus (HIV) infection, primary immunodeficiency, and after renal transplantation. Of individual features, granular debris in glands was a specific (94% specificity), but insensitive (41% sensitivity) marker for GvHD. Distinction between GvHD and CMV infection can be difficult, and GvHD can be confused with changes seen in HIV infection and other immunodeficiency states.