Extrapituitary parasellar microadenoma in Cushing's disease

Negative sellar exploration (despite the results of endocrine evaluation indicating Cushing's disease), the high incidence of failure of total hypophysectomy, and remission of Cushing's syndrome after unsuccessful hypophysectomy and sellar irradiation suggest that the etiology of refractory Cushing's disease, in some patients, lies near the sella but not in the pituitary gland. We present 5 patients, out of 626 who received surgery for Cushing's disease, in whom an ACTH-secreting extrapituitary parasellar adenoma was identified: 2 after unsuccessful total hypophysectomy for the treatment of refractory Cushing's disease, 2 after unsuccessful hemihypophysectomy (the first, 2 yr before treatment at the NIH for Nelson's syndrome; and the second, with recurrent Cushing's disease 5 yr after negative transsphenoidal exploration), and 1 with a preoperative diagnosis of an intraclival microadenoma, which was cured by resection of the tumor. In all cases, an extrapituitary parasellar microadenoma was confirmed unequivocally as the cause of the disease, by negative pathology of the resected pituitary gland (patients 1, 2, 3, and 5), and/or the remission of the disease after selective resection of the extrasellar adenoma (patients 3, 4, and 5). Three of 5 patients had a partial empty sella. These patients support the thesis that ACTH-secreting tumors can arise exclusively from remnants of Rathke's pouch, rather than from the adenohypophysis (anterior lobe or pars tuberalis of the pituitary gland) and can be a cause of Cushing's disease. In the sixth presented case, an extrapituitary tumor was suspected at surgery after negative pituitary exploration, but serial sections of the hemihypophysectomy specimen revealed a microscopic focus of tumor at the margin of the resected gland. This case demonstrates the importance of negative pituitary histology to establish the presence of an extrapituitary parasellar tumor as an exclusive source of ACTH, and it supports the value of clinical outcome to establish the diagnosis with selective adenomectomy of an extrapituitary parasellar tumor. In patients with negative pituitary magnetic resonance imaging, especially in the presence of a partial empty sella, the diagnostic and surgical approach in Cushing's disease should consider the identification and resection of extrapituitary parasellar adenoma, which can avoid total hypophysectomy, as was possible in 3 of our 5 patients.

Pharmacogenetic association between ALOX5 promoter genotype and the response to anti-asthma treatment

Clinically similar asthma patients may develop airway obstruction by different mechanisms. Asthma treatments that specifically interfere with the 5-lipoxygenase (ALOX5) pathway provide a method to identify those patients in whom the products of the ALOX5 pathway (that is, the leukotrienes) contribute to the expression of the asthma phenotype. Failure of an asthma patient to respond to treatment with ALOX5-pathway modifiers indicates that leukotrienes are not critical to the expression of the asthmatic phenotype in that patient. We previously defined a family of DNA sequence variants in the core promoter of the gene ALOX5 (on chromosome 10q11.2) associated with diminished promoter-reporter activity in tissue culture. Because expression of ALOX5 is in part transcriptionally regulated, we reasoned that patients with these sequence variants may have diminished gene transcription, and therefore decreased ALOX5 product production and a diminished clinical response to treatment with a drug targeting this pathway. Such an effect indicates an interaction between gene promoter sequence variants and drug-treatment responses, that is, a pharmacogenetic effect of a promoter sequence on treatment responses.

Lower dosages of phentermine-fenfluramine given in the afternoon: five cases with significant weight loss

Phentermine and fenfluramine are widely used in the treatment of obesity. Despite the fact that primary pulmonary hypertension and mitral valve insufficiency have been associated with fenfluramine use, many of these patients need medication to achieve weight loss. Small degrees of weight loss have been shown to significantly improve obesity-related medical conditions such as hypertension, hypercholesterolemia, and noninsulin-dependent diabetes mellitus. Current practice is to give phentermine and fenfluramine in the morning and afternoon. Doses for phentermine have ranged from 15 to 37.5 mg and for fenfluramine from 20 to 120 mg per day. We report five cases of severely obese women with medical complications who were treated with phentermine 8 mg twice per day (at 1:00 p.m. and 4:00 p.m.) and fenfluramine 20 mg per day (at 4:00 p.m.). Because many obese patients skip breakfast and eat more in the afternoon and evening, medication was dosed in order to cover these high-risk eating periods. Overall, these patients lost a mean of 22.4% of their initial weight (range 18.6% to 32.8%) over an average of 8.4 months (range 3.5 to 16 months). These cases suggest that short-term weight loss can be achieved with a low dose of fenfluramine when both medications are given in the afternoon to better target the eating patterns of obese subjects.

Barriers between guidelines and improved patient care: an analysis of AHCPR's Unstable Angina Clinical Practice Guideline. Agency for Health Care Policy and Research

OBJECTIVES

To describe common barriers that limit the effect of guidelines on patient care, with emphasis on recommendations for triage in the Agency for Health Care Policy and Research (AHCPR) Unstable Angina Clinical Practice Guideline.

DATA SOURCES

Previously reported results from a prospective clinical study of 10,785 patients presenting to the emergency department (ED) with symptoms suggestive of acute cardiac ischemia.

STUDY DESIGN

Design is an analysis of the AHCPR guideline with regard to recognized barriers in guideline implementation. Presentation of hypothetical scenarios to ED physicians was used to determine interrater reliability in applying the guideline to assess risk and to make triage decisions.

PRINCIPAL FINDINGS

The AHCPR guideline's triage recommendations demonstrate (1) poor interobserver reliability in interpretation by ED physicians; (2) limited applicability of recommendations for outpatient management (applies to 6 percent of patients presenting to the ED with unstable angina); (3) incomplete specifications of exceptions that may require deviation from guideline recommendations; (4) unexpected effects on medical care by significantly increasing the demand for limited intensive care beds; and (5) unknown effects on patient outcomes. In addition, analysis of the guideline highlights the need to address organizational barriers, such as administrative policies that conflict with guideline recommendations and the need to adapt the guideline to conform to local systems of care.

CONCLUSIONS

Careful analysis of guideline attributes, projected effect on medical care, and organizational factors reveal several barriers to successful guideline implementation that should be addressed in the design of future guideline-based interventions.

Clinical correlates of insomnia in patients with chronic illness

BACKGROUND

Patients with chronic insomnia are more likely to develop affective disorders, cardiac morbidity, and other adverse health outcomes, yet many clinicians tend to trivialize the complaint of insomnia or to attribute it only to psychiatric causes.

OBJECTIVES

To estimate the prevalence and longitudinal course of insomnia in patients with documented chronic medical illness and/or depression and to quantify the associations between specific chronic conditions and insomnia.

METHODS

The presence of mild or severe insomnia was based on responses to a sleep questionnaire completed by 3445 patients with at least 1 of 5 physician-identified chronic conditions (hypertension, diabetes, congestive heart failure, myocardial infarction, or depression) at baseline; a subsample of 1814 patients completed follow-up questionnaires at 2 years. Using multivariate techniques, we evaluated the relationship between chronic conditions, patient-reported comorbidities, and insomnia (complaints of initiating and maintaining sleep), adjusting for sociodemographics and health habits.

RESULTS

Sixteen percent of study patients had severe and 34% had mild insomnia at baseline. At 2-year follow-up, 59% (95% confidence interval, 55%-63%) of patients with mild insomnia and 83% (95% confidence interval, 78%-88%) of patients with severe insomnia at baseline still had sleep problems. Odds ratios corresponding to mild and severe insomnia for key risk factors were as follows: current depressive disorder, 2.6 and 8.2; subthreshold depression, 2.2 and 3.4; congestive heart failure, 1.6 and 2.5; obstructive airway disease, 1.6 and 1.5; back problems, 1.4 and 1.5; hip impairment, 2.2 and 2.7; and prostate problems, 1.6 and 1.4. The majority of insomnia-comorbidity associations observed at baseline persisted at 2-year follow-up.

CONCLUSIONS

Patients with insomnia require follow-up, as the majority continue to be bothered by difficulty initiating and maintaining sleep. In addition to detecting affective disorders in patients with insomnia, clinicians should focus on medical conditions that disturb sleep, especially cardiopulmonary disease, painful musculoskeletal conditions, and prostate problems.

MR and conventional angiography: work in progress toward assessing utility in radiology

RATIONALE AND OBJECTIVES

The authors assessed health-related quality of life changes associated with peripheral x-ray angiography and magnetic resonance (MR) angiography.

MATERIALS AND METHODS

Utility (the desirability or preference that individuals exhibit for a particular health state) was assessed in 30 patients with peripheral vascular disease referred for angiography by using a rating scale, additional categoric scaling questions to separate preference from experience, a willingness-to-pay technique, functional and cognitive status questions, and a time trade-off technique. All patients underwent both MR angiography and x-ray angiography.

RESULTS

Patients reported significantly (P < .05) less anxiety after the test, less pain after the test, fewer new physical limitations, and less effect on performance of daily activities with MR angiography. Findings from the overall rating scale and categoric scaling questions also significantly (P < .05) favored MR angiography. Patients were willing to pay a mean of 2.12% of annual income to avoid MR angiography and a mean of 7.41% to avoid x-ray angiography. The median quality-adjusted life gain required by patients to undergo the procedures was 52.5-60 days for x-ray angiography and 10.5 days for MR angiography, without discounting.

CONCLUSION

X-ray angiography has more profound short-term adverse effects on life than does MR angiography. Preference-based measures can be adapted to elicit patient values for short-term health states as seen in radiology.

Successful reversal of acute vascular rejection in a renal allograft with combined mycophenolate mofetil and tacrolimus as primary immunotherapy

Despite the use of newer immunosuppressive drugs, early allograft rejection is still a major cause of graft loss and diminished graft survival. The pathological picture of acute interstitial rejection usually responds to high dose steroids, whereas the treatment of acute vascular (AVR) rejection characterized by an intense vasculitis and/or endotheliolitis is more formidable. The use of newer monoclonal antibodies specific for T lymphocytes and their subsets has only been occasionally successful in reversing AVR. Here we report a case of successful reversal of acute vascular renal allograft rejection with mycophenolate mofetil (MMF) and tacrolimus as primary therapy.

Predicting Clostridium difficile stool cytotoxin results in hospitalized patients with diarrhea

OBJECTIVE

To validate a model for the prediction of Clostridium difficile cytotoxin assay results, and to identify a subgroup of patients with a very low likelihood of C. difficile-associated disease in whom the yield of routine cytotoxin testing is low.

DESIGN

Prospective cohort study. Relevant clinical symptoms, signs, and antibiotic exposure were recorded before reporting of assay results. Each predictor was assigned a score based on regression coefficients, and patients were stratified according to their total score.

SETTING

Two urban, tertiary care, university hospitals.

PATIENTS

A total of 609 consecutive adult inpatients who received testing for C. difficile cytotoxin during a 3-month period in 1994.

MEASUREMENTS AND MAIN RESULTS

The prevalence of positive cytotoxin assays was 8% in the validation set, compared with 14% in the derivation set. Defining patients without both prior antibiotic use and at least one symptom predictor (significant diarrhea or abdominal pain) as a low-risk subgroup, the misclassification rate was 2.8% (5/177) for assay results; of the five misclassified cases patients, only one was judged to have C. difficile-associated disease. Use of this rule to identify low-risk patients could have potentially averted 29% of all cytotoxin assays.

CONCLUSIONS

Patients without a history of antibiotic use and either significant diarrhea or abdominal pain are unlikely to have positive C. difficile cytotoxin assays and may not require cytotoxin testing.

The profile of HIV infection in women: a challenge to the profession

Human Immunodeficiency Virus (HIV) has become a leading cause of morbidity and mortality among women and children in the United States. As advances are made in the area of diagnosis and treatment of HIV infection, strategies must be developed to support the psychosocial needs of women with HIV disease. The diagnosis of HIV infection in women and their children presents a unique array of complicated social, emotional and medical consequences. Care must be provided in a holistic manner with special emphasis on the needs of women within a systemic context.

The use of empiric clinical data in the evaluation of practice guidelines for unstable angina

OBJECTIVE

To determine the applicability to emergency department (ED) clinical practice of a nationally disseminated practice guideline on the disposition of patients with a diagnosis of unstable angina, and to determine the potential impact of the guideline on hospital admissions and demand for intensive care beds.

DESIGN

Application of guideline criteria for ED disposition decisions to a validation sample derived from a prospective clinical trial.

SETTING

Five hospitals, including 2 urban general teaching hospitals, 2 urban tertiary care university hospitals, and 1 suburban university-affiliated community hospital.

PATIENTS

A consecutive sample of 457 patients who presented with symptoms suggestive of acute cardiac ischemia and who had "unstable angina" or "rule out unstable angina" diagnosed by ED physicians. Greater than 90% of eligible patients were enrolled in the clinical trial; follow-up data sufficient for assignment of a definitive diagnosis were obtained for 99% of subjects.

MAIN OUTCOME MEASURES

Acute myocardial infarction and unstable angina, based on blind review of initial and follow-up clinical data, including cardiac enzyme levels and electrocardiograms. After completion of the trial, without knowledge of final diagnosis or outcome, the investigators classified patients into risk groups specified by the unstable angina guideline.

RESULTS

Of subjects with an ED diagnosis of unstable angina, only 6% (n=28) met the guideline's criteria corresponding to low risk for adverse events and were therefore suitable for discharge directly to home. Fifty-four percent (n=247) met the intermediate-risk criteria; 40% (n=182) met the high-risk criteria and were identified as requiring admission to an intensive care unit. Actual ED disposition differed from guideline recommendations in 2 major areas: only 4% (1/28) of low-risk patients were discharged to home with outpatient follow-up, and only 40% (72/182) of high-risk patients were admitted to an intensive care unit.

CONCLUSIONS

Although the guideline was intended to reduce hospitalization by identifying a low-risk group, the small size of this group among ED patients suggests that little reduction in hospitalization can be expected. Indeed, the guideline may increase demand for the limited number of intensive care beds to accommodate patients with unstable angina considered high-risk but currently placed elsewhere. These results emphasize the need to use empiric data from target clinical settings to assess the likely actual impact of guidelines on clinical care prior to national dissemination.

Two 21-kilodalton components of the Epstein-Barr virus capsid antigen complex and their relationship to ZEBRA-associated protein p21 (ZAP21)

The viral capsid antigen complex of Epstein-Barr virus (EBV), an important serodiagnostic marker of infection with the virus, consists of at least four components, with molecular masses of 150, 110, 40, and 21 kDa. Here we show that the 21-kDa component of the viral capsid antigen consists of products of two EBV genes, BFRF3 and BLRF2. Both products were expressed from late transcripts, were recognized by human antisera, and were present in virions. The BFRF3 product, but not that of BLRF2, fulfilled the definition of ZEBRA-associated protein p21 (ZAP21). In cells in which EBV was lytically replicating, BFRF3 protein was coimmunoprecipitated together with ZEBRA by a rabbit antiserum directed against amino acids 197 to 245 of BZLF1. In EBV-negative cells cotransfected with BZLF1 and BFRF3 expression vectors, BFRF3 was also coimmunoprecipitated with this antiserum. Although this antiserum could not detect BFRF3 on an immunoblot, it was able to immunoprecipitate BFRF3 in the absence of ZEBRA expression. The rabbit antiserum to amino acids 197 to 245 of BZLF1 was found to detect the same epitope at the carboxy end of BFRF3 as was recognized by rabbit antiserum to BFRF3 itself. Thus, coimmunoprecipitation of BFRF3 p21 with ZEBRA appeared to be due to cross-reactivity of the immunoprecipitating antiserum rather than to direct association of ZEBRA and BFRF3 p21.

Cushing's disease preceded by generalized glucocorticoid resistance: clinical consequences of a novel, dominant-negative glucocorticoid receptor mutation

Generalized glucocorticoid resistance is associated with chronic hyperactivation of the hypothalamic-pituitary-adrenal axis, compensating for impaired glucocorticoid receptor function. We report a unique patient with sporadic generalized glucocorticoid resistance who, at age 33, presented with infertility and hypertension and, at 38, developed pituitary Cushing's disease. Leukocyte-binding studies revealed normal affinity of the glucocorticoid receptor but a reduction of binding sites by 50%. [3H]thymidine incorporation by this patient's lymphocytes was not suppressible by dexamethasone. He had a novel heterozygous missense mutation in the glucocorticoid receptor gene (isoleucine 559 to asparagine 559). The mutant receptor exhibited a strong dominant-negative effect on the ability of the wild-type receptor to induce gene transcription in vitro. The mutation was present in all of the patient's cultured lymphoblasts and fibroblasts as well as in 50% of his sperm, as demonstrated by single-cell polymerase chain reaction; it was not present in his parents and seven siblings. This novel mutation was thus both de novo and present in the germ line. Immunohistochemical staining of this patient's pituitary corticotropinoma revealed accumulation of p53 protein, indicating the presence of a putative somatic oncogenic mutation in the p53 gene in the tumor cells. Investigation of the lymphoblast and skin fibroblast cultures for p53 abnormalities did not show any aberration. Thus, a novel de novo germ line mutation of the glucocorticoid receptor with strong dominant-negative activity caused severe sporadic generalized glucocorticoid resistance, which preceded corticotroph adenoma formation. The latter probably was due to the combined effects of chronic corticotroph hyperstimulation, decreased glucocorticoid negative feedback, and at least one subsequent somatic defect in the control of the cell cycle.

Clinical prediction rules to optimize cytotoxin testing for Clostridium difficile in hospitalized patients with diarrhea

BACKGROUND

Although routine testing of hospitalized patients with diarrhea for Clostridium difficile cytotoxin has been advocated as a high-yield procedure, the rationale for this practice has been questioned. To target a low-yield subgroup for whom routine testing could be deferred, we derived a clinical decision rule for predicting results of the C difficile cytotoxin assay in hospitalized adults with diarrhea.

METHODS

We hypothesized a priori that two variables, antibiotic use (within 30 days prior to testing) and history of significant diarrhea (new onset of > 3 partially formed or watery stools per 24 hour period), would be highly predictive of cytotoxin results, and obtained these data on 480 consecutive patients who underwent diagnostic testing for C difficile at a university hospital and affiliated Veterans Affairs medical center. For more detailed modelling, we recorded symptoms, signs, comorbidity, and other potential causes of diarrhea for 68 test positive patients (cases) and 265 randomly selected test negative patients (controls) within the study cohort.

RESULTS

The overall prevalence of positive cytotoxin assays was 14%. Prior antibiotic therapy (OR = 9.0, 95% CI 2.1-38.4), significant diarrhea (OR = 2.2, 95% CI 1.1-4.7), and abdominal pain (OR = 1.9, 95% CI 0.96-3.7) were independent predictors of cytotoxin assay results. The model discriminated patients with positive and negative assays with a receiver operating characteristic (ROC) area of 0.68; observed and predicted probabilities of a positive cytotoxin assay were well correlated over the entire range of observed probabilities (r2 = 0.86). A decision rule (defined as positive if prior antibiotic use and either significant diarrhea or abdominal pain are present) demonstrated sensitivity and specificity of 86 and 45%. When applied to the entire dataset (N = 480), a simplified a priori rule, defined as positive if both prior antibiotic use and history of significant diarrhea are present, demonstrated sensitivity, specificity, positive and negative predictive value of 80, 45, 18 and 94%, respectively (6% of those predicted to be cytotoxin-negative actually tested positive). Use of this rule would have averted 39% of cytotoxin assays in our study population.

CONCLUSIONS

Patients without prior antibiotic use and either significant diarrhea or abdominal pain are unlikely to have positive C difficile cytotoxin assay results, and may not routinely require cytotoxin testing.

Comparison of positron emission tomography, cognition, and brain volume in Alzheimer's disease with and without severe abnormalities of white matter

OBJECTIVES

To examine cerebral metabolism, cognitive performance, and brain volumes in healthy controls and two groups of patients with probable Alzheimer's disease, one group with severe abnormalities of white matter (DAT+) and the other group with none, or minimal abnormalities (DAT-).

METHODS

Neuropsychological tests, CT, MRI, quantitative MRI, and PET studies were carried out to allow comparison between the DAT+ and DAT- groups and the healthy controls.

RESULTS

Compared with the healthy controls, both demented groups had significantly reduced global and regional cerebral metabolism, significant brain atrophy, and significantly lower scores on neuropsychological testing. The DAT- patient group showed a pattern of parietal-temporal cerebral metabolic reductions and neuropsychological performance deficits typical of Alzheimer's disease. In addition, metabolism in the association neocortex (AD ratio) and measures of neuropsychological task performance were significantly correlated in the DAT- patient group. Comparison of DAT+ with DAT- patients showed a significantly higher ratio of parietal to whole brain glucose utilisation for the DAT+ group. Moreover, when comparing group z score differences from the healthy controls, the DAT+ group had, on average, smaller differences from controls in the frontal, parietal, and temporal regions than did the DAT- group. Discriminant analysis using metabolic ratios of the frontal, parietal, and temporal regions showed cerebral metabolic patterns to be significantly different among the DAT+, the DAT-, and the healthy controls. These differences were due primarily to relatively higher frontal, parietal, and temporal metabolic ratios in the DAT+ group which resulted in discriminant scores for the DAT+ group between the healthy controls and the DAT- group. Group mean scores on tests of neuropsychological performance were not significantly different between the DAT- and DAT+ patients. By contrast with the DAT- group, however, no significant correlations between the AD ratio and any neuropsychological task were seen in the DAT+ group. Multiple regression analysis showed significant between group differences in the relation between the AD ratio and neuropsychological scores on three tasks. The slopes of the relations between the AD ratio and memory scores (memory and freedom from distractability deviation quotient of the Wechsler adult intelligence scale (WMDQ)) also were significantly different for the two groups.

CONCLUSIONS

Although multiple causes for abnormalities of white matter exist in patients with Alzheimer's disease, these data suggest that the presence of severe abnormalities of white matter indicate a second pathological process in the DAT+ patients. The DAT- patients showed the parietal-temporal metabolic deficits and correlations between association neocortical metabolism and neuropsychological task performance typical of patients with Alzheimer's disease. By contrast, the DAT+ group had a pattern of cerebral metabolism significantly different from healthy controls and DAT+ patients, as well as no significant correlations between metabolism in the association neocortex and neuropsychological performance. These differences probably reflect the superimposed pathology of the abnormalities of white matter which may exert their affect through disruption of long corticocortical pathways.

Nelson's syndrome associated with a somatic frame shift mutation in the glucocorticoid receptor gene

Nelson's syndrome is the appearance and/or progression of ACTH-secreting pituitary macroadenomas in patients who had previously undergone bilateral adrenalectomy for Cushing's disease. Extremely high plasma ACTH levels and aggressive neoplastic growth might be explained by the lack of appropriate glucocorticoid negative feedback due to defective glucocorticoid signal transduction. To study the glucocorticoid receptor (GR) gene in Nelson's syndrome, DNA was extracted from pituitary adenomas and leukocytes of four patients with this condition and amplified by PCR for direct sequence analysis. In one of the tumors, a heterozygous mutation, consisting of an insertion of a thymine between complementary DNA nucleotides 1188 and 1189, was found in exon 2. This frame-shift mutation led to premature termination at amino acid residue 366 of the wild-type coding sequence, excluding the expression of a functioning receptor protein from the defective allele. The mutation was not detected in the sequence of the GR gene in the patient's leukocyte DNA, indicating a somatic origin. By lowering the receptor number in tumorous cells, this defect might have caused local resistance to negative glucocorticoid feedback similar to that caused by the presence of a null allele in a kindred with the generalized glucocorticoid resistance syndrome. P53 protein accumulation, previously reported in 60% of corticotropinomas, could not be detected in any of the four pituitary tumors examined by immunohistochemistry. We suggest that a somatic GR defect might have played a pathophysiological role in the tumorigenesis of the corticotropinoma bearing this mutation.

Increased human immunodeficiency virus (HIV) type 1 DNA content and quinolinic acid concentration in brain tissues from patients with HIV encephalopathy

Levels of human immunodeficiency virus type 1 (HIV-1) DNA and quinolinic acid were examined in areas of the central nervous system (CNS) and lymphoid organs (LN) from 5 AIDS patients with no clinically apparent CNS compromise (group I), 7 with CNS opportunistic diseases (group II), and 8 with HIV encephalopathy (group III). The brains from patients with HIV encephalopathy not only contained higher levels of HIV-1 DNA (cerebrum, P < .01; cerebellum, P < .05) as assessed by quantitative polymerase chain reaction but also showed a higher rate of viral pol region mutations suggestive of zidovudine or didanosine resistance than brains from patients in group I or II (P < .01). CNS quinolinic acid concentrations were significantly higher in group II and III patients than in group I (P = .03), even though quinolinic acid levels in LN were comparable among the 3 groups. These data suggest that CNS inflammatory changes associated with HIV encephalopathy may be triggered by a local productive HIV-1 infection within the CNS.

Fc gamma RII, Fc gamma RIII, and CD18 receptors mediate in part neutrophil activation on a plasma coated expanded polytetrafluoroethylene surface

BACKGROUND

A biomaterial-induced polymorphonuclear neutrophil (PMN) defect may predispose the implanted vascular graft to infection. PMNs bind, activate, and undergo morphologic changes when exposed to uncoated or plasma coated expanded polytetrafluoroethylene (ePTFE) surfaces. The purpose of this study was to investigate whether the CD18 integrin receptor or the immunoglobulin receptors Fc gamma RII and Fc gamma RIII mediate either PMN binding or activation on ePTFE.

METHODS

PMN binding and activation were determined after incubation of these cells on human immunoglobulin (IgG) or fibrinogen coated surfaces and uncoated or plasma coated ePTFE. PMN activation was measured by using the ferricytochrome reduction assay. Binding was determined with chromium 51-labeled PMNs. To block the Fc gamma RII, Fc gamma RIII, and CD18 receptors, PMNs were preincubated with the monoclonal antibodies (mAbs) IV.3, 3G8, and IB4, respectively. Irrelevant isotype matched mAbs were used as control.

RESULTS

Monoclonal antibody IB4 inhibited binding of activated PMNs to fibrinogen coated surfaces. Binding to IgG was affected by either mAb IB4 or IV.3, but the greatest degree of inhibition was achieved when mAbs IB4 and IV.3 were used in combination. IgG-induced activation was partially inhibited by mAb IV.3 but was fully inhibited by a combination of mAbs IB4 and IV.3 The mAbs did not affect PMN binding to uncoated or plasma coated ePTFE, nor was PMN activation on the uncoated ePTFE surface inhibited. PMN activation on the plasma coated ePTFE surface was, however, partially inhibited by the combination of mAb IB4 with either mAb IV.3 or 3G8.

CONCLUSIONS

A synergistic interaction between the PMN Fc gamma RII receptor and the CD18 integrin receptor accounts for surface bound IgG-induced cell activation. Both receptors also play a role in mediating PMN activation on the plasma-coated ePTFE surface.

Circle of Willis: evaluation with spiral CT angiography, MR angiography, and conventional angiography

PURPOSE

To evaluate the use of spiral computed tomographic (CT) angiography in the analysis of the arteries of the circle of Willis and compare these results with magnetic resonance (MR) angiography and conventional angiography.

MATERIALS AND METHODS

The results in 17 patients who underwent examination were prospectively studied in a blinded fashion. The presence or absence of the arteries of the circle of Willis was determined by using maximum intensity projection reconstructions from CT angiography and MR angiography. These results were compared with results from conventional angiography.

RESULTS

Similar sensitivities were determined for CT angiography (88.5%) and MR angiography (85.5%); however, MR angiography was found to differ significantly (P = .005) from conventional angiography. No significant differences (P > .05) were found between the two modalities and conventional angiography in the detection of the anterior, middle, or posterior cerebral arteries or the anterior communicating artery.

CONCLUSION

Spiral CT angiography is highly sensitive in the detection of arterial anatomy in the circle of Willis and is a reliable alternative to MR angiography.

A phase I and II trial of dose-intensified cyclophosphamide and GM-CSF in pediatric malignant brain tumors

PURPOSE

Cyclophosphamide is commonly used in the treatment of children with malignant brain tumors. The purpose of this study was to develop a multicycle, high-dose intensity cyclophosphamide regimen with granulocyte-macrophage colony-stimulating factor (GM-CSF) and to assess its activity against malignant glioma and primitive neuroectodermal tumor (PNET).

METHODS

Twenty-three patients with brain tumors, including 15 with malignant glioma and six with PNET, were enrolled. Cyclophosphamide (1.8-2.25 g/m2/day for 2 days i.v.; total dose 3.6-4.5 g/m2) was administered and was followed by recombinant human GM-CSF (5 micrograms/kg/day s.c.) on days 3-11 or until the absolute granulocyte count reached 1.5 x 10(9)/L.

RESULTS

With a total of 83 cycles administered, the mean dose intensity of cyclophosphamide ranged from 1.5 g/m2/week through cycle 2 (22 patients) to 0.8 g/m2/week through cycle 8 (two patients). No activity was seen against malignant glioma, and five of six patients with PNET had partial responses. The mean duration of a neutrophil count of < 0.5 x 10(9)/L was only 8 days; the platelet recovery was substantially longer. Fever during neutropenia occurred in 54 of 83 cycles. One patient died from transfusion-related graft-versus-host disease.

CONCLUSIONS

A cyclophosphamide regimen equal to twice the dose intensity of that used in conventional therapy was administered. The regimen was active against PNET but inactive against malignant glioma.

Neurosyphilis in HIV-positive and HIV-negative patients: neuroimaging findings

PURPOSE

To evaluate and describe the neuroimaging findings of patients with neurosyphilis.

METHODS

The neuroimaging studies of 35 patients with documented neurosyphilis were reviewed. Diagnosis was established in 34 patients with cerebrospinal fluid for a Venereal Disease Research Laboratory test, complemented by autopsy in 1 and brain biopsy in 1. All patients had reactive fluorescent treponemal antibody tests with absorption in their sera. Imaging studies included plain and contrast-enhanced CT of the brain, plain and gadolinium-enhanced MR, MR angiography, and conventional angiography. Imaging findings were also correlated with the relevant pathologic findings at autopsy in three additional patients with neurosyphilis who did not have brain imaging studies.

RESULTS

Of the 35 patients with imaging studies, 32 tested human immunodeficiency virus (HIV)-seropositive, and 3 were HIV-seronegative. Eleven (31%) of 35 patients had normal radiographic findings. Cerebral infarctions were seen in 8 (23%) of 35 patients, and nonspecific white matter lesions in 7 (20%) of 35. Cerebral gummas and extraaxial enhancement indicating meningitis were noted in 2 (6%) of 35 patients, respectively. Arteritis was demonstrated in 2 (50%) of 4 patients who underwent either MR angiography or conventional angiography. The 3 subjects who had autopsy but not imaging studies were found to have manifestations of meningovascular syphilis, including syphilitic leptomeningitis and an obliterative endarteritis.

CONCLUSION

We conclude that findings of vascular occlusive disease manifested as infarction or arteritis, enhancing cortical lesions with or without adjacent meningeal enhancement, focal or diffuse extraaxial enhancement, and white matter disease, although nonspecific, in the proper clinical setting should prompt appropriate testing for neurosyphilis, a treatable disease, in patients with and without HIV infection.

Clinical and pathological features of an autosomal dominant, adult-onset leukodystrophy simulating chronic progressive multiple sclerosis

OBJECTIVE

To study the clinical and pathological features of a kindred with an adult-onset autosomal dominant leukodystrophy.

PATIENTS

Five symptomatic and nine asymptomatic at-risk members of the kindred.

INTERVENTIONS

Subjects underwent detailed histories and general and neurologic examinations. Further evaluation included electroencephalography, evoked potentials, electromyography, autonomic testing, and analysis of serum, urine, and cerebrospinal fluid. One patient underwent sural nerve biopsy and analysis. Another, previously studied patient, underwent a limited autopsy.

RESULTS

Cerebellar and pyramidal dysfunction began in the fourth and fifth decades of life; subtle autonomic symptoms were often present years earlier. Frontal lobe dysfunction and abnormalities of the central visual pathways were mild and of late onset. Sensorineural hearing loss was common. The peripheral nervous system was spared. Autopsy results of one patient revealed severe degeneration of the white matter at all levels of the neuraxis, but most prominent in the frontoparietal and cerebellar regions, with sparing of the subcortical U fibers. Histological and ultrastructural examinations failed to show evidence of a specific pathogenetic mechanism or etiology.

CONCLUSION

This disorder seems to be a distinct type of hereditary leukodystrophy, but its exact nature remains unknown.

Neutrophil activation by expanded polytetrafluoroethylene is dependent on the induction of protein phosphorylation

BACKGROUND

Polymorphonuclear leukocyte (PMN) activation after interaction with implantable surfaces has been previously reported. The purpose of this study was to examine the mechanism of PMN activation in response to expanded polytetrafluoroethylene (ePTFE).

METHODS

To demonstrate PMN activation, the cumulative production of superoxide was measured on uncoated, plasma coated, or albumin coated ePTFE discs. Chromium 51-labeled PMNs were used to measure binding. Cell structure was examined by scanning electron microscopy.

RESULTS

By 4 hours, PMN activation on either uncoated or plasma coated ePTFE was approximately 30% of phorbol 12-myristate 13-acetate-induced activation. Albumin inhibited PMN activation by ePTFE. No apparent correlation existed between chromium 51-labeled PMN binding and cell activation on the surfaces. Pretreatment of the cells with the protein kinase inhibitors bisindolylmaleimide or genistein resulted in marked inhibition of superoxide production on the uncoated and plasma coated ePTFE surfaces, whereas binding to these surfaces was not affected. PMNs spread on the uncoated surface and transmigrated into the plasma coated ePTFE surface. These effects of ePTFE on cell structure were inhibited by bisindolylmaleimide and genistein.

CONCLUSIONS

ePTFE induced PMN activation, as measured by superoxide production, and changes in cell behavior are dependent on the activation of signaling pathways that involve protein phosphorylation events.

The cost-effectiveness of early surgery versus watchful waiting in the management of small abdominal aortic aneurysms

PURPOSE

The purpose of this study was to compare the relative cost-effectiveness of two clinical strategies for managing 4 to 5 cm diameter abdominal aortic aneurysms (AAAs): early surgery (repair 4 cm AAA when diagnosed) versus watchful waiting (monitor AAA with ultrasound size measurements every 6 months and repair if the diameter reaches 5 cm).

METHODS

We used a Markov decision tree to compute the expected survival in quality-adjusted life years (QALYs) for each strategy, based on literature-derived estimates for the probabilities of different outcomes in this model. We determined hospital costs for patients undergoing elective and emergency AAA repair at our center. With standard methods of cost accounting, we then calculated the additional cost per year of life saved by early surgery compared with watchful waiting (cost-effectiveness ratio, dollars/QALY).

RESULTS

Mean hospital costs for elective and emergency AAA repair were $24,020 and $43,208, respectively (1992 dollars). For our base-case analysis (60-year-old men with 4 cm diameter AAAs, with 5% elective operative mortality rate and 3.3% annual rupture rate), early surgery improved survival by 0.34 QALYs compared with watchful waiting, at an incremental cost of $17,404/QALY. Increased elective surgical mortality rate, decreased AAA rupture risk, and increased patient age all reduced the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery. Future increases in elective operative risk, noncompliance with ultrasound follow-up and increased threshold size for elective AAA repair during watchful waiting all improved the cost-effectiveness of early surgery.

CONCLUSIONS

The cost effectiveness of early surgery for 4 cm diameter AAAs in carefully selected patients compares favorably with that of other commonly accepted preventive interventions such as hypertension screening and treatment. With an upper limit of $40,000/QALY as an "acceptable" cost-effectiveness ratio, early surgery appears to be justified for patients 70 years old or younger, if the AAA rupture risk is 3%/year or more and the elective operative mortality rate is 5% or less. Although not a substitute for clinical judgment, this cost-effectiveness analysis delineates the essential tradeoffs and uncertainties in treating patients with small AAAs.

Choreoathetosis after surgery for congenital heart disease

Choreoathetosis developed in three patients after cardiopulmonary bypass with hypothermia. None had significant hypotension or hypoxemia; all had hypocapnia and respiratory alkalosis during the rewarming period. We postulate that hypocapnia-induced cerebral vasoconstriction may have contributed to ischemic damage in focal central nervous system areas.

Progressive multifocal leukoencephalopathy complicating Wiskott-Aldrich syndrome. Report of a case and review of the literature of progressive multifocal leukoencephalopathy with other inherited immunodeficiency states

OBJECTIVE

To describe the occurrence of progressive multifocal leukoencephalopathy (PML) in association with Wiskott-Aldrich syndrome, an X-linked recessive disorder with impairment of both cellular and humoral immunity.

DESIGN

A detailed analysis of this patient's clinical illness, immunologic factors, neuroradiographic findings, and brain histopathologic conditions was undertaken. The medical literature on PML complicating congenital immunodeficient states was also reviewed.

SETTING

A 1500-bed, university-affiliated, public health hospital.

PATIENT

A 15-year-old boy with Wiskott-Aldrich syndrome. His neurologic illness was heralded by dysarthria and right-sided weakness and the diagnosis was established by brain biopsy specimen. Survival from the time of onset of PML was 10 months.

CONCLUSION

Although PML typically occurs in the setting of severe acquired cellular immunodeficiency, often as a consequence of acquired immunodeficiency syndrome, organ transplantation, and leukemia and lymphoma, it may rarely accompany inherited immunodeficiency syndromes. The reported childhood cases of PML include three patients, aged 5, 11, and 18 years, with other inherited immunodeficiency syndromes. This patient represents the first time (to our knowledge) that PML has been reported to occur in association with Wiskott-Aldrich syndrome.

Childhood ataxia with diffuse central nervous system hypomyelination

A significant number of patients with progressive leukodystrophy do not have a definitive diagnosis. This report describes the clinical, morphological, and biochemical characteristics of 4 unrelated girls with progressive ataxic diplegia of unknown etiology. These patients had normal development until the ages of 1.5 to 5 years. A diffuse confluent abnormality of the white matter of the central nervous system was present on computed tomography and magnetic resonance scans obtained early in the course of the illness. Dementia was not present and peripheral nerves were normal. All patients were evaluated for known metabolic and degenerative diseases and no abnormalities were observed. Light and electron microscopy of open-brain biopsy specimens from 2 girls showed selective white matter abnormalities including hypomyelination, demyelination, and gliosis. Myelin-specific proteins in the subcortical white matter were examined immunocytochemically and by Western blot analysis. They were of normal molecular size but were markedly reduced in quantity in both patients compared to control subjects. Lipid analysis revealed decreased levels of characteristic myelin lipids. When examined by magnetic resonance spectroscopic imaging, all patients showed a marked decrease of N-acetylaspartic acid, choline, and creatine in white matter only. The magnetic resonance spectroscopic imaging profile is a unique diagnostic feature of this clinicopathological syndrome.

AU-A, an RNA-binding activity distinct from hnRNP A1, is selective for AUUUA repeats and shuttles between the nucleus and the cytoplasm

The 3'-untranslated regions of many labile transcripts contain AU-rich sequences that serve as cis determinants of mRNA stability and translational efficiency. Using a photocrosslinking technique, our laboratory has previously defined three cytoplasmic RNA-binding activities specific for the AUUUA multimers found in the 3'-untranslated regions of lymphokine mRNAs. One of these activities, AU-A, has an apparent molecular mass of 34 kDa, is constitutively expressed in both primary T cells and the Jurkat T cell leukemia line, and binds to a variety of U-rich RNA sequences. Previous studies had shown that AU-A is more prevalent in the nucleus than the cytoplasm, raising the possibility that AU-A is really a nuclear RNA-binding activity that is found in cytoplasmic extracts because of nuclear leakage during cell fractionation. We now show that AU-A shuttles between the cytoplasm and the nucleus. Our results indicate that AU-A is a candidate protein component of ribonucleoprotein complexes that participate in nucleocytoplasmic transport of mRNA and cytoplasmic mRNA metabolism. The properties of AU-A activity are similar to those of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1). However, using monoclonal antibodies to hnRNP A1 and protease digestion patterns, we show that AU-A activity and hnRNP A1 protein are distinct. These studies have also allowed us to define a fourth RNA-binding activity of apparent molecular mass 41 kDa with specificity for AUUUA multimers. This activity is restricted to the nucleus and contains the hnRNP C protein.

Systemic histiocytosis presenting as multiple sclerosis

A patient resembling one with progressive multiple sclerosis in clinical presentation and by magnetic resonance imaging was studied in detail. Some features atypical for multiple sclerosis prompted a persistent search for an alternative cause. The diagnosis of a non-Langerhans systemic histiocytosis involving brain and bone was established and showed a partial response to radiation therapy. This patient illustrates the continued importance of a broad approach to the evaluation of possible multiple sclerosis, with particular attention to atypical features.

Discounting in cost-effectiveness analysis of healthcare programmes

Discounting is a technique commonly used in cost-effectiveness analysis to 'make fair' comparisons of programmes whose costs and outcomes occur at different times. It is not a correction for inflation. While there is general agreement among health economists regarding the need to discount, there is less consensus on the procedure for discounting costs or benefits. We describe the method of constant-rate discounting, which uses the same rate to discount costs and benefits, and examine its impact on the cost effectiveness of selected health interventions. This methodology has significant limitations, however. Constant-rate discounting may not accurately represent the values of a society. Furthermore, discounting does not reflect the longitudinal time preferences of individuals (or groups). The philosophical rationale for constant-rate discounting is the concept of longitudinal equity, i.e. that society should make allocation decisions in such a way that present and future cohorts are treated equally, regardless of when they come into existence. In general, discounting affects the cost effectiveness of preventive interventions more than acute interventions, and it affects programmes with immediate cost more that those with ongoing cost. The reader of such analyses should be aware of these effects, and should use caution in comparing the cost effectiveness of interventions with vastly different timing of cost and benefit.

Neurosyphilis. A comparative study of the effects of infection with human immunodeficiency virus

BACKGROUND

The course of neurosyphilis has been reported to be altered by human immunodeficiency virus (HIV) infection. Prior reports of neurosyphilis occurring in association with HIV infection have been largely anecdotal and have failed to compare neurosyphilis in patients with HIV infection with an uninfected control group. This study was performed to determine if the clinical presentation encountered is different in the presence of HIV infection.

DESIGN

A retrospective, hospital-based, case series study based on chart review encompassing a 64-month period.

SETTING

The study was performed in a large, university-affiliated, public health trust hospital in south Florida.

PATIENTS

Forty-six hospitalized patients with neurosyphilis were identified; 13 patients fulfilled Centers for Disease Control and Prevention (Atlanta, Ga) criteria for acquired immunodeficiency syndrome (AIDS), 11 were HIV seropositive only, and 22 were HIV uninfected. Neurosyphilis was determined by a reactive cerebrospinal fluid VDRL slide test.

RESULTS

The HIV-infected patients (both AIDS and HIV-seropositive groups) were younger and more frequently had features of secondary syphilis, such as rash, fever, adenopathy, headache, or meningismus. Significant differences were observed in cerebrospinal fluid measurements when the HIV-infected group was compared with the HIV-uninfected group, including a higher mean white blood cell count in patients with AIDS and a higher mean protein level and a lower mean glucose level in the HIV-infected group. Syphilitic meningitis was more common in HIV-seropositive patients, although the HIV-uninfected patients presented with a greater variety of types of neurosyphilis. Ophthalmic syphilis was observed more frequently in the HIV-infected group.

CONCLUSIONS

Significant differences exist between neurosyphilis occurring in the presence and absence of HIV infection.

Thyrotropin-secreting pituitary carcinoma

Pituitary tumors rarely metastasize outside the central nervous system. Of the more than 100 reported TSH-secreting adenomas, we now describe the first carcinoma. A 40-yr-old woman had transsphenoidal surgery for a large TSH-secreting pituitary adenoma in 1984. She had increased thyroid hormone levels with a TSH that varied from 16-31 microU/mL, and an unusually high alpha-subunit that ranged from 125-150 ng/mL. Because of residual tumor, she had a left craniotomy in 1985 followed by radiation. Despite these therapies, she had a residual tumor that remained stable until January 1989 when her tumor nearly doubled in size. She received radiation therapy and octreotide with marked diminution of the tumor and clinical improvement. In August 1989, she presented with leg weakness, and magnetic resonance imaging revealed a large sacral mass. A biopsy confirmed that the sacral mass was a metastasis from the pituitary tumor. Due to additional metastases in the lung, she received 5-fluorouracil, cytoxan, and adriamycin, with marked decrease in her lesions. Further substantiation of the metastatic pituitary tumor was made when the patient returned in December 1989 with a pleural effusion containing pituitary tumor cells. Of all the reported cases of TSH-secreting adenomas, this case had the highest alpha-subunit portending future metastases. Furthermore, the apparent response to octreotide and response to chemotherapy are encouraging and suggest that new therapies should be explored. Finally, since TSH-secreting adenomas tend to be more invasive than other pituitary tumors, this case underscores the need for early diagnosis and aggressive treatment of these tumors.

Management of small abdominal aortic aneurysms. Early surgery vs watchful waiting

OBJECTIVE

To compare two clinical strategies for the management of small abdominal aortic aneurysms (AAAs) less than 5 cm in diameter: early surgery (repair small AAAs when diagnosed) and watchful waiting (measure AAA size every 6 months and repair when the diameter reaches 5 cm).

DATA SOURCES

We reviewed data from an earlier longitudinal study of patients with small AAAs to estimate incidence rates of rupture or acute expansion. Estimates for other parameters in the model were obtained by searching the medical literature (MEDLINE, 1966 to present).

DATA SYNTHESIS

We constructed a Markov decision tree to compare early surgery with watchful waiting in patients with asymptomatic AAAs less than 5 cm in diameter, with respect to long-term survival in quality-adjusted life years. The average annual rates of rupture or acute expansion for AAAs with a maximal transverse diameter of less than 4.0, 4.0 to 4.9, and at least 5.0 cm, are 0, 3.3, and 14.4 events per 100 patient-years of observation, respectively. At an average rupture rate of 3.3 events per 100 patient-years and an average operative risk for elective surgery (4.6%, 30-day mortality), our model predicts that early surgery improves survival in patients who present with a 4-cm AAA. The benefit of early surgery decreases with increased age at presentation. If the average rupture rate for AAAs less than 5 cm is assumed to be low (eg, 0.4 event per 100 patient-years), watchful waiting if favored, particularly as operative risk increases. The decision in this subgroup, however, is sensitive to possible future increases in operative risk.

CONCLUSIONS

In the majority of scenarios that we examined, early surgery is preferred to watchful waiting for patients with AAAs less than 5 cm in diameter. Watchful waiting is generally favored, however, for patients with a low risk of AAA rupture or acute expansion, including those patients who present with very small AAAs (eg, < 4 cm). More accurate data concerning the rupture risk of AAAs less than 5 cm would improve clinical decision making.

Transcriptional synergy by the Epstein-Barr virus transactivator ZEBRA

ZEBRA is an Epstein-Barr virus (EBV) transcriptional activator that mediates a genetic switch between the latent and lytic states of the virus by binding to the promoters of genes involved in lytic DNA replication and activating their transcription. A computer survey revealed that 9 of 23 potential or known ZEBRA-responsive EBV genes contained two or more upstream binding sites; this suggested that ZEBRA can stimulate transcription synergistically. By using a series of synthetic promoters bearing one, two, three, five, and seven upstream recognition sites, we showed that ZEBRA activates transcription synergistically when templates bearing multiple sites were compared with a template bearing a single site. This phenomenon was observed in both uninfected and EBV-infected B-lymphoid cells and in vitro in a HeLa cell nuclear extract. DNase I footprinting was used to show that the synergy was not due to cooperative DNA binding mediated by direct contact between ZEBRA dimers. The in vitro experiments revealed two manifestations of synergy. One was seen when the levels of transcription observed with the same amounts of ZEBRA added to templates bearing different numbers of sites were compared. The other was observed when the two lowest concentrations of ZEBRA that stimulated measurable transcription from any given template were compared. On the basis of both the number of sites and the calculated Kd of ZEBRA for a single site, we estimated that the critical concentration of ZEBRA needed to elicit transcriptional synergy corresponds to a site occupancy of two or three bound ZEBRA dimers. Our results have biologic implications for both the EBV lytic cycle and other processes in which the concentration of an activator changes either temporally or spatially.

Magnetic resonance demonstration of intracranial CSF flow in children

We determined the feasibility and value of studying intracranial CSF flow in children with potential CSF pathway problems using a cardiac gated cine magnetic resonance (MR) format. We studied 15 consecutive patients with a variety of clinical problems that suggested possible CSF pathway problems. The diagnoses included Chiari malformation, Dandy-Walker syndrome, external hydrocephalus, cerebellar tumor, CNS histoplasmosis, and tuberculous meningitis. In addition to documenting the feasibility of the technique in children (7 of 15 were less than 2 years of age), we derived significant new information relative to pathogenesis and/or therapy. The study provides preliminary evidence supporting intracranial CSF flow studies at the time of routine MR imaging of appropriate children.

Viral proteins associated with the Epstein-Barr virus transactivator, ZEBRA

The BamHI Z Epstein-Barr replication activator (ZEBRA) mediates disruption of latency and induction of Epstein-Barr virus (EBV) early gene expression in latently infected lymphocytes. Polyclonal rabbit sera raised against ZEBRA were used to immunoprecipitate ZEBRA-associated proteins (ZAPs). ZAPs of 19, 21, 23, and 42 kDa were coimmunoprecipitated with ZEBRA from extracts of EBV-producing lymphoid cell lines. ZAPs were not recognized directly by the rabbit sera, but they were antigenic for EBV+ human sera. Immunoprecipitation of ZAPs by ZEBRA-specific antisera required the presence of ZEBRA. ZAPs were not coprecipitated with ZEBRA from mouse cells expressing only ZEBRA, from Raji (a cell line in which EBV is unable to complete lytic replication), or from cells treated with inhibitors of viral DNA synthesis. Thus, ZAPs are late EBV-encoded proteins. ZEBRA and ZAPs colocalized to a salt-insoluble nuclear fraction, and both were found extracellularly in crude preparations of virions. ZAPs might function to affect the cellular localization of ZEBRA, to alter its capacity to transactivate, or to influence its target gene specificity.

Clonal composition of pituitary adenomas in patients with Cushing's disease: determination by X-chromosome inactivation analysis

The synthesis and secretion of anterior pituitary hormones are subjected to a variety of positive and negative feedback mechanisms. Aberrancies of these highly regulated phenomena may lead to hyperplasia involving multiple cells of the anterior lobe. Alternatively, a rare genetic mutation in a single cell may precede its clonal expansion. Which of these mechanisms is operative in the development of corticotroph adenomas is not known. To examine this question, we studied the clonal composition of ACTH-producing pituitary adenomas from female patients with Cushing's disease by using X-chromosome inactivation analysis. Nine of 27 patients examined were heterozygous at 1 of the 2 X-chromosome-linked polymorphic loci, hypoxanthine-phosphoribosyl-transferase and phosphoglycerate-kinase. The methylation patterns of the hypoxanthine-phosphoribosyl-transferase and phosphoglycerate-kinase genes, distinguishing between the active and inactive alleles, were analyzed in DNA extracted from the central part of the tumor and compared with those of autologous lymphocyte DNA. Six tumors (4 microadenomas and 2 macroadenomas) showed a single active allele of the X-chromosome-linked genes and were monoclonal in nature. The other 3 pituitary adenomas (1 microadenoma and 2 macroadenomas, 1 from a patient with Nelson's syndrome) revealed a polyclonal pattern of X-chromosome inactivation. Our data demonstrate that corticotroph adenomas of the pituitary may arise from a single cell or from more than one cell. Whether fundamentally different endocrine mechanisms underlie the two processes remains to be seen.

Petrosal sinus sampling with and without corticotropin-releasing hormone for the differential diagnosis of Cushing's syndrome

BACKGROUND

Measurement of adrenocorticotropin levels in plasma from the inferior petrosal sinuses of patients with Cushing's syndrome can distinguish adrenocorticotropin-secreting pituitary tumors (Cushing's disease) from other causes of the syndrome, principally ectopic adrenocorticotropin secretion from an occult tumor. However, it is unknown whether such measurement consistently identifies patients with Cushing's disease and whether testing with corticotropin-releasing hormone (CRH) enhances the value of the procedure.

METHODS

We prospectively studied 281 patients with Cushing's syndrome to evaluate the diagnostic efficacy of the procedure. Bilateral sampling was successfully accomplished in 278 patients, with no major morbidity; 262 of these patients underwent sampling before and after administration of ovine CRH. The adrenocorticotropin levels in the samples were used to calculate the ratio of the concentration in plasma from the inferior petrosal sinuses to the concentration in peripheral-blood plasma (the IPS:P ratio).

RESULTS

The diagnosis of 246 patients was confirmed surgically as Cushing's disease in 215, as ectopic adrenocorticotropin syndrome in 20, and as primary adrenal disease in 11. An IPS:P ratio greater than or equal to 2.0 in basal samples identified 205 of the 215 patients with Cushing's disease (sensitivity, 95 percent), with no false positive results (specificity, 100 percent). A peak IPS:P ratio greater than or equal to 3.0 after CRH administration identified all 203 of the patients with Cushing's disease who received CRH (sensitivity, 100 percent), with no false positive results (specificity, 100 percent). The sensitivity was much lower when the adrenocorticotropin concentrations in the samples from one sinus were considered alone. In patients with Cushing's disease a difference of greater than or equal to 1.4-fold between the concentrations in the two sinuses (the adrenocorticotropin gradient) predicted the location of the microadenoma in 68 percent of 104 patients during basal sampling and in 71 percent of 105 patients after CRH administration.

CONCLUSIONS

Simultaneous bilateral sampling of plasma from the inferior petrosal sinuses, with the adjunctive use of CRH, distinguishes patients with Cushing's disease from those with ectopic adrenocorticotropin secretion with high diagnostic accuracy.

Malignant clear cell hidradenoma: a case report and literature review

Malignant clear cell hidradenoma is an uncommon variant of sweat gland tumors. Histological sections show lobulated masses and anastomising cords of cells which were polygonal to slightly fusiform in appearance. Most of the cells have bland appearing ovoid nuclei with slightly eosinophilic to clear cytoplasm. Focal areas within the lesion may show malignant changes. These areas may demonstrate large pleomorphic hyperchromatic nuclei, numerous mitotic figures, and a tendency toward squamous differentiation with many of the neoplastic cells demonstrating individual keratinization. Treatment is wide local resection. Consideration of regional lymph node dissection should be entertained because of the tendency to angiolymphatic spreads. Radiotherapy has not been shown to be helpful. Various chemotherapeutic regimens have been tried with inconclusive results. An illustrative case report is presented.

Ambulatory EEG recordings in children with infrequent seizures

Twenty-one children, ages 1-15 years, were selected for outpatient ambulatory electroencephalographic (AEEG) monitoring on the basis of infrequent seizures without therapy, normal routine EEGs, and normal neurologic/developmental examinations. Technically satisfactory recordings were obtained in all patients; recording time consisted of 24, 22, and 6 hours for 15, 4, and 2 patients, respectively. Eighteen patients were not receiving antiepileptic drug therapy at AEEG. The follow-up intervals after the AEEG ranged from 4-20 months. Only 2 patients had epileptiform AEEGs. Of the remaining 19 with nonepileptiform records, 10 were seizure free without antiepileptic drug therapy, but 9 developed additional seizures which required treatment.

Adoptive immunotherapy of intracerebral metastases in mice

Lymphokine-activated killer (LAK) cells are a heterogeneous population of immune effector cells that nonspecifically destroy neoplastic cells but not normal cells. Although parenteral treatment with interleukin-2 (IL-2) alone or a combination of IL-2 and LAK cells reduces tumor load and prolongs survival in mice with pulmonary, peritoneal, or hepatic metastases, the effect of these treatments on brain metastases has not been studied. To determine in an animal model if intracerebral metastases would be protected by the immunologically privileged status of the brain, intracardiac and intravenous injections of 10(5) KHT sarcoma cells were performed in C3H mice to create brain and lung metastases, respectively. The mice were treated with adoptive immunotherapy to determine if efficacy seen in an extracerebral site could be reproduced in the brain, and if histological examination of these brains would reveal a significant degree of lymphocyte infiltration and cytolytic activity. Animals were treated with either parenteral IL-2 (7500 U three times daily on Days 3 to 7 after tumor injection), or IL-2 plus LAK cells (7500 U IL-2 times daily on Days 3 to 7, and 10(8) LAK cells intravenously on Days 3 and 6 after tumor injection), or IL-2 excipient (three times daily on Days 3 to 7 after tumor injection). As compared to control animals, pulmonary metastases on Day 14 after tumor injection were reduced or eliminated in animals treated with either IL-2 or IL-2 plus LAK cells (p less than 0.01). In these same animals, there was no reduction in the number of intracerebral metastases and no evidence of lymphocytic infiltration or cytolytic activity in the brain. This is the first study that reveals an organ-specific resistance to the treatment of metastases with adoptive immunotherapy, and affirms the concern that due to inadequate trafficking of endogenous or exogenous-activated lymphocytes or due to inadequate activation of in situ brain lymphoid precursors, there is no rejection of tumors in the brain. This information suggests that brain metastases in patients with systemic malignancies will not respond to intravenous treatment with LAK cells and IL-2, and that alternative forms of treatment are needed. Furthermore, this modification of a previously existing model of murine brain metastasis provides a method for concurrently evaluating the effectiveness of treatments for intra- and extracranial cancers.

Neurosyphilis in acquired immunodeficiency syndrome

In a retrospective study encompassing 42 months (January 1984 through July 1987), 12 patients were identified as having both neurosyphilis and acquired immunodeficiency syndrome. These patients constituted 44% of the entire group meeting rigorous diagnostic criteria for neurosyphilis and 1.5% of all patients hospitalized with acquired immunodeficiency syndrome. The typical patient with acquired immunodeficiency syndrome and neurosyphilis was young (mean age, 37 years) and male (83%). All had serological evidence of syphilis in both blood and cerebrospinal fluid. Syphilitic eye disease was surprisingly common in this group, occurring in 5 (42%). Four patients (33%) had been previously treated for syphilis. In 2, treatment for latent syphilis had been completed 3 and 5 months, respectively, before neurosyphilis was documented. Neurosyphilis is not uncommon in patients with acquired immunodeficiency syndrome in our population. In light of its diverse manifestations, syphilis should be considered in the differential diagnosis of any human immunodeficiency virus type 1-infected individual presenting with neurological, psychiatric, or ophthalmological disease.

A case of developmental right hemisphere dysfunction: implications for psychiatric diagnosis and management

The authors present the case of an adult woman who was treated in the mental health system for many years for a syndrome of mixed anxiety and depression unresponsive to psychopharmacologic or psychotherapeutic treatment. A computed tomography scan revealed asymmetrical enlargement of the right temporal horn. This finding, as well as findings of severe difficulties in spatial relations together with mildly abnormal posturing of the left hand when walking (especially when the gait was stressed), suggested that the patient had a developmental disability of the right cerebral hemisphere. The authors conclude that because such patients might appear to have primarily psychiatric rather than neurologic problems, the diagnosis of right hemisphere dysfunction should be considered when the clinical presentation is indicative of atypical anxiety and affective disorders.