Immunophenotype, proliferation, DNA ploidy, and biological behavior of gastrointestinal stromal tumors: a multivariate clinicopathologic study

To determine the prognostic impact of clinical, immunohistochemical, and biological parameters, we examined 52 gastrointestinal stromal tumors (GIST) by conventional light microscopy and immunohistochemistry. DNA ploidy was analyzed by image cytometry on cytospin preparation. The proliferative activity was determined by mitosis counting and assessment of Ki-67 reactivity by means of monoclonal antibody Ki-S5. A histopathologic grade was assigned to each tumor according to the French Federation of Cancer Centers (FNCLCC) grading system. Next to vimentin, CD34 was the most prevalent antigen, followed by markers of neural and muscular differentiation. Many tumors exhibited a mixed phenotype. Twenty-one tumors were diploid, eight hypodiploid, and 23 aneuploid. In univariate analysis, tumor grade, Ki-S5 labeling index, mitotic count, atypical mitoses, cellularity, and sex were predictive of both mortality and metastasis risk. DNA ploidy only correlated with overall survival, whereas the tumor location affected the occurrence of metastases. Multivariate analysis selected Ki-S5 scores (P < .0001) and atypical mitoses (P=.012) as independent prognosticators for overall survival, and tumor grade (P=.0036) and size (P=.0055) as predictors of metastatic spread. We conclude that GIST are primitive mesenchymal tumors capable of divergent differentiation, which does not influence their prognosis. The latter appears to be best predicted by histopathologic grading and the Ki-67 labeling index.

Single-center randomized trial comparing tacrolimus (FK506) and cyclosporine in the prevention of acute myocardial rejection

BACKGROUND

To compare the efficacy and safety of tacrolimus and cyclosporine in heart transplantation, this single-center, prospective, randomized, open-label clinical trial was undertaken.

METHODS

Seventy-three adult patients were randomly assigned at the time of transplantation to receive either tacrolimus (n=43) or cyclosporine (n=30) as the primary immunosuppressant. Ten of the 43 patients in the tacrolimus group received the drug intravenously in the perioperative period; all other patients received only oral tacrolimus.

RESULTS

With a mean follow-up of 27 months, patient survival rates (tacrolimus 83%, cyclosporine 81%) were similar. Fewer patients experienced acute rejection in the tacrolimus group (79%) than in the cyclosporine group (100%), but the difference was not statistically significant. The number of infections and dialysis and insulin requirements were similar for the 2 treatment groups, but the proportion of patients requiring multidrug antihypertensive regimens was lower in the tacrolimus group (12.5% vs 50.0% at month 6; p=.025). The interpatient variance in pharmacokinetic parameters in a subset of 10 patients was much higher after the first oral dose of tacrolimus than at steady-state (eg, first-dose time at which maximal concentration is reached (t(max)): 3.5+/-2.5h, steady-state t(max): 2.0+/-0.7h), and patients treated with intravenous tacrolimus (n=13) rather than oral tacrolimus (n=30) reached target concentrations faster and with less interpatient variability (eg, at day 0: 9.72+/-10.9 ng/mL intravenously vs 3.31+/-8.1 orally).

CONCLUSIONS

Tacrolimus was associated with similar efficacy and safety profiles compared with cyclosporine. The higher interpatient variance in absorption associated with oral tacrolimus during the first few days after transplantation would suggest that intravenous tacrolimus should be used during the perioperative period.

Validation of deconvolutional analysis for the measurement of hepatic function in dogs with toxic-induced liver disease

The extraction of the hepatobiliary radiopharmaceutical 99mTc-mebrofenin (Choletec) by the liver can be used to evaluate the severity of hepatocellular disease. The hepatic parenchymal cells extract mebrofenin from the blood by the same active transport mechanism as bilirubin. The ability of the liver to extract 99mTc-mebrofenin is a measure of hepatic parenchymal cell function. In this study, we induced hepatocellular disease by administration of a hepatotoxic drug and compared a direct method of determining the hepatic extraction of 99mTc-mebrofenin to hepatic extraction fraction derived from deconvolutional analysis. We also compared both methods of calculating the hepatic extraction of 99mTc-mebrofenin to liver histopathology. Hepatic extraction fraction derived from deconvolutional analysis correlated very well to the direct measurement technique (R=0.922, p < 0.001). Both methods of determining hepatic extraction correlated well to quantitative histopathology, having the same correlation coefficient and p values. (R=-0.833, p=0.003). As the hepatic extraction 99mTc-mebrofenin decreased, the severity of the histopathologic lesions of the liver increased in a linear fashion. There was a significant correlation of the hepatic excretion T1/2 to quantitative histopathology (R=0.949, p < 0.001). The hepatic excretion T1/2 increased as the severity of the histopathologic lesions of the liver increased. Hepatic extraction (HEF) and excretion of 99mTc-mebrofenin are good predictors of the severity of hepatocellular damage in toxic induced liver disease. This study helps validate the premise that HEF derived from deconvolutional analysis is a good predictor of the actual first pass hepatic extraction of 99mTc-mebrofenin.

Hepatic extraction efficiency of technetium-99m-mebrofenin in the dog with toxic-induced acute liver disease

Extraction of the hepatobiliary radiopharmaceutical 99mTc-N-(3-bromo-2,4,6-trimethyacetanilide) iminodiacetic acid (mebrofenin; Choletec, Squibb Diagnostic, Princeton, NJ) by the liver may be used as an index of hepatocellular function. The hepatic parenchymal cells extract mebrofenin from the blood using the same active transport mechanism as bilirubin.

METHODS

In this study, we induced hepatocellular disease by administering a hepatotoxic drug and compared the hepatic extraction efficiency (HEE), measured directly from an afferent injection of 99mTc-mebrofenin, to quantitative histopathology and to serum biochemistry analysis.

RESULTS

The baseline HEE was 95.9% +/- 2.71% (mean +/- s.d.). Dogs that were affected by the hepatotoxic drug had reduced HEE. HEE correlated well to the severity of histologic lesions (r = -0.83, p = 0.003). HEE also correlated well to the increases in the activities of alanine aminotransferase (ALT; r = -0.85, p = 0.002) and aspartate aminotransferase (AST; r = -0.89, p = <0.001), the concentration of fasting bile acid (r = -0.97, p = <0.001), bilirubin (r = -0.92, p = <0.001) and, to a lesser degree, to the activities of alkaline phosphatase (Alk Phos; r = -0.73, p = 0.016). HEE had higher correlation coefficients to the serum biochemistry analysis than did the quantitative liver histopathology.

CONCLUSION

Hepatic extraction of 99mTc-mebrofenin is a good predictor of the severity of hepatocellular damage in toxic-induced liver disease.

Diagnosis and management of gastroesophageal reflux in infants and children

Use of histamine blockers, proton pump inhibitors, and prokinetic drugs, along with traditional antacids, has become standard therapy for gastroesophageal reflux (GER) in symptomatic adults. Response to this therapy is assessed to confirm the diagnosis of GER, and is often advocated as the best way to establish the causes and effects of the disease. It is well documented that reflux occurs throughout the life span. However, the incidence in children is difficult to estimate, requiring interpretation of behavior and symptoms in nonverbal and atypical presentations. Unfortunately, the diagnosis of GER in children is often made after the development of complications such as aspiration pneumonia, esophagitis, or ulcers. Early recognition and intervention by primary care providers is necessary to prevent such serious complications of untreated GER. This article presents the pathophysiology and clinical manifestations of GER. Diagnosis in children is discussed, and recommendations for empiric therapy, including conservative measures and drug therapies, are presented.

A case of localized retinal damage in thallium poisoning

PURPOSE

To determine the cause of visual impairment and to document the late eye disturbances in a case of thallium poisoning.

PATIENT

A 44-year-old woman presented with a history of repeated attacks of complete alopecia over a period of several months, diffuse pain in both legs, transient gastrointestinal disturbances, abasia with a progressive paraparesis, paresthesia in the fingertips, and polyneuropathy. She complained of slowly progressive visual deterioration in both eyes which began about six months after the first attack of alopecia. The optic discs showed distinct signs of temporal atrophy together with a deep temporal excavation. The Goldmann perimetry revealed an absolute central scotoma. Traces of thallium were found in the urine and in the serum. The district attorney later discovered that her husband had been trying to poison her with thallium.

METHODS

The clinical and electrophysiological examinations included visual evoked potentials (VEP) and electroretinography (flash ERG, multifocal ERG and pattern ERG).

RESULTS

The VEP showed a reduction in amplitude and a prolonged latency indicating a conduction block. The pattern ERG was initially normal. At a follow-up examination 6 years later, a slight amplitude reduction in the pattern ERG was found. The multifocal ERG showed a diminished amplitude in the center of the retina (up to +/- 10 degrees visual angle).

CONCLUSIONS

The electrophysiological investigations in our patient--who had an optic atrophy--indicated a conduction block of the retinal nerve fibers (VEP) and an additional lesion at or before the retinal bipolar cells (multifocal ERG), localized in the central +/- 10 degrees. These findings suggest that thallium poisoning can lead to a combined lesion of the retinal nerve fibers and the neural retina.

Functional properties of CD4+ CD28- T cells in the aging immune system

The aging immune system is characterized by a progressive decline in the responsiveness to exogenous antigens and tumors in combination with a paradoxical increase in autoimmunity. From a clinical viewpoint, deficiencies in antibody responses to exogenous antigens, such as vaccines, have a major impact and may reflect intrinsic B cell defects or altered performance of helper T cells. Here we describe that aging is associated with the emergence of an unusual CD4 T cell subset characterized by the loss of CD28 expression. CD28 is the major costimulatory molecule required to complement signaling through the antigen receptor for complete T cell activation. CD4+ CD28- T cells are long-lived, typically undergo clonal expansion in vivo, and react to autoantigens in vitro. Despite the deficiency of CD28, these unusual T cells remain functionally active and produce high concentrations of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2). The loss of CD28 expression is correlated with a lack of CD40 ligand expression rendering these CD4 T cells incapable of promoting B cell differentiation and immunoglobulin secretion. Aging-related accumulation of CD4+ CD28- T cells should result in an immune compartment skewed towards autoreactive responses and away from the generation of high-affinity B cell responses against exogenous antigens. We propose that the emergence of CD28-deficient CD4 T cells in the elderly can partially explain age-specific aberrations in immune responsiveness.

The influence of sex on the phenotype of rheumatoid arthritis

OBJECTIVE

To explore whether there are different disease patterns of rheumatoid arthritis (RA) in women and men.

METHODS

We studied 55 male case patients and 110 female control patients who developed RA between 1970 and 1985 and who resided and received medical care in Olmsted County, Minnesota, for at least 10 years after the diagnosis of RA. Case and control patients were matched for the date of first diagnosis. The pattern and extent of joint involvement, the frequency of joint surgeries, and the presence and type of extraarticular manifestations were determined by retrospective chart review.

RESULTS

Incidence rates in women were variable and age dependent, whereas the risk in men older than 36 years was constant over their lifetime. Erosive disease was more frequent in men than in women (72% versus 55%, respectively; P < 0.05) and tended to occur earlier (47% versus 31% for erosive disease within the first 4 years of RA). Although male sex was correlated with a higher risk of bony erosions and an accelerated course of RA, structural consequences of joint destruction were more pronounced in women. Joint surgery was performed more frequently in women (50%) than in men (27%) (P = 0.01). In particular, the frequencies of arthroplasties and arthrodeses of hand and foot joints were different (34 procedures in women versus 1 procedure in men; P < 0.001). Sex influenced the risk as well as the pattern of organ involvement in RA. Nodules and rheumatoid lung disease were typical manifestations in men (P = 0.001 and P < 0.001, respectively), whereas women typically developed sicca syndrome (P = 0.05). Despite differences in disease aggressiveness and disease pattern, there was little difference in the medical therapy in the men compared with the women.

CONCLUSION

RA is a heterogeneous disease with variations in phenotype. Sex-associated factors influence disease severity as well as disease pattern. Because sex-related effects influence treatment goals, treatment responses, and side effects, they should be considered in clinical study design and analysis as well as in the treatment decisions for individual patients with RA.

SPring-8 in-vacuum undulator beam test at the ESRF

Before the commissioning of SPring-8, the in-vacuum hybrid undulator developed at SPring-8 had been brought to the ESRF for the first beam test in the summer of 1996. The purpose of this test was to investigate the influence of the in-vacuum undulator on the beam and check its vacuum system. However, heating by the resistive wall impedance turned out to be a critical issue for the in-vacuum undulators.

Cardiovascular effects of the alpha2-adrenergic receptor agonist medetomidine in clinically normal cats anesthetized with isoflurane

OBJECTIVE

To assess the cardiovascular effects of the alpha2-adrenergic receptor agonist medetomidine in healthy cats anesthetized with 2% isoflurane.

ANIMALS

11 clinically normal cats.

PROCEDURE

Cats were anesthetized with isoflurane, and catheters were inserted for measurement of aortic, left ventricular, and right atrial pressures. For data collection, end-tidal isoflurane concentration was reduced to 2%, and end-tidal CO2 was maintained at 35 to 40 mm of Hg by use of positive-pressure ventilation. After measurement of baseline data, medetomidine (0.01 mg/kg of body weight, i.m.) was administered and data were collected continuously for 75 minutes. At the end of data collection, incisions were closed and cats were allowed to recover from anesthesia.

RESULTS

Medetomidine significantly increased mean arterial pressure and systemic vascular resistance. The increase in mean arterial pressure was maximal at 17.8 +/- 7 minutes after medetomidine administration. Medetomidine also increased left ventricular peak systolic pressure, left ventricular end diastolic pressure, and right atrial pressure. Medetomidine significantly decreased heart rate and mean aortic flow.

CONCLUSIONS

The low dosage of medetomidine (0.01 mg/kg, i.m.) promoted severe vasoconstriction in isoflurane-anesthetized cats, and resulted in sustained increases in left ventricular preload and afterload.

Long-term experience with pentosanpolysulfate in interstitial cystitis

OBJECTIVES

An oral preparation of pentosanpolysulfate sodium (PPS) was recently approved by the Food and Drug Administration for interstitial cystitis (IC). Previously published articles have documented improvement in symptoms in 28% to 63% of patients, but no long-term studies have been published. No unique characteristics except for Hunner's ulcer have been found in patients experiencing relief from PPS. We report our experience with PPS following patients up to 116 months and analyze baseline parameters in an attempt to characterize long-term responders.

METHODS

Baseline and follow-up data from 97 patients with IC and enrolled in a compassionate use study with PPS at the University of Wisconsin from 1987 to 1995 are analyzed. Previous treatments had failed, and patients had to pay for PPS. Patients continuing treatment with PPS were monitored every 3 months with questionnaires and laboratory tests. In 1996 an update on medication and a questionnaire developed by the National Institutes of Health Interstitial Cystitis Database were sent to patients who had discontinued treatment.

RESULTS

By the end of the study period 11 (11.3%) of the patients were still taking PPS, with 6 (6.2%) doing so continuously for more than 18 months. Three (3%) patients who discontinued PPS were in long-term remission. An additional 15% had remission for a substantial period. Except for a weak correlation between less constant pain (P = 0.0439), no correlations were found between baseline parameters and duration of treatment with PPS.

CONCLUSIONS

On a long-term basis, between 6.2% and 18.7% of patients with IC benefit from PPS. The only baseline factor predicting response to PPS was less constant pain.

Neuroendocrine tumors of the uterus

Neuroendocrine tumors of the uterus are rare. When present, the majority is found in the uterine cervix. Several theories on the histogenesis of these tumors have been proposed including an origin from local neuroendocrine cells or from reserve cells. The latter hypothesis is supported by the fact that not too seldom uterine neuroendocrine tumors contain other histological components including adenocarcinoma and squamous cell carcinoma or even both. A firm diagnosis can usually the rendered when immunostainings and/or electron microscopy are performed, in addition to conventional light microscopy and Grimelius stain. The tumors react positively for a diversity of so-called neuroendocrine markers and several hormonal substances. Ultrastructurally, they contain dense- core neurosecretory granules. Prognosis is usually poor with most patients dying within one year from diagnosis. Survival can only be achieved in patients who present with early disease.

Iodine-123 alpha-methyl tyrosine single-photon emission tomography of cerebral gliomas: standardised evaluation of tumour uptake and extent

Single-photon emission tomography (SPET) with the amino acid analogue l-3-[123I]iodo-alpha-methyl tyrosine (IMT) is helpful in the diagnosis and monitoring of cerebral gliomas. Radiolabelled amino acids seem to reflect tumour infiltration more specifically than conventional methods like magnetic resonance imaging and computed tomography. Automatic tumour delineation based on maximal tumour uptake may cause an overestimation of mean tumour uptake and an underestimation of tumour extension in tumours with circumscribed peaks. The aim of this study was to develop a program for tumour delineation and calculation of mean tumour uptake which takes into account the mean background activity and is thus optimised to the problem of tumour definition in IMT SPET. Using the frequency distribution of pixel intensities of the tomograms a program was developed which automatically detects a reference brain region and draws an isocontour region around the tumour taking into account mean brain radioactivity. Tumour area and tumour/brain ratios were calculated. A three-compartment phantom was simulated to test the program. The program was applied to IMT SPET studies of 20 patients with cerebral gliomas and was compared to the results of manual analysis by three different investigators. Activity ratios and chamber extension of the phantom were correctly calculated by the automatic analysis. A method based on image maxima alone failed to determine chamber extension correctly. Manual region of interest analysis in patient studies resulted in a mean inter-observer standard deviation of 8.7% +/ -6.1% (range 2.7% -25.0%). The mean value of the results of the manual analysis showed a significant correlation to the results of the automatic analysis (r = 0.91, P<0. 0001 for the uptake ratio; r = 0.87, P<0.0001 for the tumour area). We conclude that the algorithm proposed simplifies the calculation of uptake ratios and may be used for observer-independent evaluation of IMT SPET studies. Three-dimensional tumour recognition and transfer to co-registered morphological images based on this program may be useful for the planning of surgical and radiation treatment.

BARE-1 insertion site preferences and evolutionary conservation of RNA and cDNA processing sites

The BARE-1 copia-like retrotransposon constitutes nearly 7% of the barley (Hordeum vulgare L.) genome as a family of more than 2 x 10(4) mostly full-length copies dispersed on all chromosomes. BARE-1 elements are transcribed in barley tissues from promoters within the LTR (long terminal repeat). The predicted, translated polyprotein contains conserved domains for GAG, aspartic proteinase, integrase, reverse-transcriptase, and RNase H. Here, we have used inverse PCR with LTR-based primers to establish the consensus sequences for the terminal region of the LTR, the external dinucleotides of the cDNA integration intermediate, and the minus- and plus-strand priming sites. These key functional entities are well-conserved in the BARE-1 family, including wheat Wis2, but differ from those of other plant retrotransposons. The target site duplication was established as 5 bp. Of the 13 integration sites identified here, 8 were other BARE-1 elements and 1 another retrotransposon; 59% of the total 17 identified BARE-1 insertion sites are retrotransposons. This nested insertion pattern may represent a basic feature of plant retrotransposons.

O-15-Butanol-PET-Aktivierungsstudie zur zerebralen Repräsentation deklarativer Gedächtnisvorgänge

Ziel: Untersuchungen zur zerebralen Repräsentation deklarativer Gedächtnisvorgänge mit der Positronen-Emissions-Tomographie an gesunden rechtshändigen Normalprobanden. Methoden: Bei sechs Probanden erfolgten sechs 0-15-Butanol-PET-Untersuchungen (jeweils 1500 MBq) mit einer GE 4096+ PET-Kamera. Die Gedächtnisaufgabe bestand darin, zwölf Wortpaare hoch bildhaften Gehaltes zu lernen (auditorische Präsentation über Kopfhörer). Bei der nachfolgenden Abfrage wurden randomisiert jeweils die ersten Worte präsentiert und die Probanden hatten dann die dazugehörenden Worte zu assoziieren. Als Referenzbedingungen wurden Nichtworte dargeboten. Die Datenanalyse erfolgte mit »Statistischem Parametrischem Mapping« (SPM 96) unter MatLab (Version 4.2). Ergebnisse: Die Gedächtnisleistung (Anteil der richtigen Assoziationen) der Probanden war hoch. Während des Lernvorganges wurden Aktivierungen - in Form von Anstiegen des rCBF - im anterioren Gyrus cinguli, sowie im linken und rechten präfrontalen Kortex beobachtet. Während der Abfrage zeigten sich Aktivierungen im linken und rechten Precuneus, im linken präfrontalen Kortex sowie im anterioren Gyrus cinguli. Schlußfolgerung: Die Untersuchung deklarativer Lern- und Gedächtnisvorgänge mittels 0-15-Butanol-PET weist auf die Beteiligung eines distribuierten Netzes von Hirnregionen hin. Darüber hinaus zeigt sich im Vergleich von Lernen und Abfrage eine unterschiedliche Involvierung der präfrontalen Gehirnregionen und eine wichtige Rolle des Precuneus bei der Erinnerung von Gedächtnisinhalten.