Novelty preference assessed by eye tracking: A sensitive measure of impaired recognition memory in epilepsy

OBJECTIVE

Epilepsy patients often report memory deficits despite normal objective testing, suggesting that available measures are insensitive or that non-mnemonic factors are involved. The Visual Paired Comparison Task (VPCT) assesses novelty preference, the tendency to fixate on novel images rather than previously viewed items, requiring recognition memory for the "old" images. As novelty preference is a sensitive measure of hippocampal-dependent memory function, we predicted impaired VPCT performance in epilepsy patients compared to healthy controls.

METHODS

We assessed 26 healthy adult controls and 31 epilepsy patients (16 focal-onset, 13 generalized-onset, 2 unknown-onset) with the VPCT using delays of 2 or 30 s between encoding and recognition. Fifteen healthy controls and 17 epilepsy patients (10 focal-onset, 5 generalized-onset, 2 unknown-onset) completed the task at 2-, 5-, and 30-minute delays. Subjects also performed standard memory measures, including the Medical College of Georgia (MCG) Paragraph Test, California Verbal Learning Test-Second Edition (CVLT-II), and Brief Visual Memory Test-Revised (BVMT-R).

RESULTS

The epilepsy group was high functioning, with greater estimated IQ (p = 0.041), greater years of education (p = 0.034), and higher BVMT-R scores (p = 0.024) compared to controls. Both the control group and epilepsy cohort, as well as focal- and generalized-onset subgroups, had intact novelty preference at the 2- and 30-second delays (p-values ≤ 0.001) and declined at 30 min (p-values > 0.05). Only the epilepsy patients had early declines at 2- and 5-minute delays (controls with intact novelty preference at p = 0.003 and p ≤ 0.001, respectively; epilepsy groups' p-values > 0.05).

CONCLUSIONS

Memory for the "old" items decayed more rapidly in overall, focal-onset, and generalized-onset epilepsy groups. The VPCT detected deficits while standard memory measures were largely intact, suggesting that the VPCT may be a more sensitive measure of temporal lobe memory function than standard neuropsychological batteries.

Proposed mechanisms of tau: relationships to traumatic brain injury, Alzheimer's disease, and epilepsy

Traumatic brain injury (TBI), Alzheimer's disease (AD), and epilepsy share proposed mechanisms of injury, including neuronal excitotoxicity, cascade signaling, and activation of protein biomarkers such as tau. Although tau is typically present intracellularly, in tauopathies, phosphorylated (p-) and hyper-phosphorylated (hp-) tau are released extracellularly, the latter leading to decreased neuronal stability and neurofibrillary tangles (NFTs). Tau cleavage at particular sites increases susceptibility to hyper-phosphorylation, NFT formation, and eventual cell death. The relationship between tau and inflammation, however, is unknown. In this review, we present evidence for an imbalanced endoplasmic reticulum (ER) stress response and inflammatory signaling pathways resulting in atypical p-tau, hp-tau and NFT formation. Further, we propose tau as a biomarker for neuronal injury severity in TBI, AD, and epilepsy. We present a hypothesis of tau phosphorylation as an initial acute neuroprotective response to seizures/TBI. However, if the underlying seizure pathology or TBI recurrence is not effectively treated, and the pathway becomes chronically activated, we propose a "tipping point" hypothesis that identifies a transition of tau phosphorylation from neuroprotective to injurious. We outline the role of amyloid beta (Aβ) as a "last ditch effort" to revert the cell to programmed death signaling, that, when fails, transitions the mechanism from injurious to neurodegenerative. Lastly, we discuss targets along these pathways for therapeutic intervention in AD, TBI, and epilepsy.

In-scanner head motion and structural covariance networks

In-scanner head motion systematically reduces estimated regional gray matter volumes obtained from structural brain MRI. Here, we investigate how head motion affects structural covariance networks that are derived from regional gray matter volumetric estimates. We acquired motion-affected and low-motion whole brain T1-weighted MRI in 29 healthy adult subjects and estimated relative regional gray matter volumes using a voxel-based morphometry approach. Structural covariance network analyses were undertaken while systematically increasing the number of included motion-affected scans. We demonstrate that the standard deviation in regional gray matter estimates increases as the number of motion-affected scans increases. This increases pairwise correlations between regions, a key determinant for construction of structural covariance networks. We further demonstrate that head motion systematically alters graph theoretic metrics derived from these networks. Finally, we present evidence that weighting correlations using image quality metrics can mitigate the effects of head motion. Our findings suggest that in-scanner head motion is a source of error that violates the assumption that structural covariance networks reflect neuroanatomical connectivity between brain regions. Results of structural covariance studies should be interpreted with caution, particularly when subject groups are likely to move their heads in the scanner.

Estimation of in-scanner head pose changes during structural MRI using a convolutional neural network trained on eye tracker video

INTRODUCTION

In-scanner head motion is a common cause of reduced image quality in neuroimaging, and causes systematic brain-wide changes in cortical thickness and volumetric estimates derived from structural MRI scans. There are few widely available methods for measuring head motion during structural MRI. Here, we train a deep learning predictive model to estimate changes in head pose using video obtained from an in-scanner eye tracker during an EPI-BOLD acquisition with participants undertaking deliberate in-scanner head movements. The predictive model was used to estimate head pose changes during structural MRI scans, and correlated with cortical thickness and subcortical volume estimates.

METHODS

21 healthy controls (age 32 ± 13 years, 11 female) were studied. Participants carried out a series of stereotyped prompted in-scanner head motions during acquisition of an EPI-BOLD sequence with simultaneous recording of eye tracker video. Motion-affected and motion-free whole brain T1-weighted MRI were also obtained. Image coregistration was used to estimate changes in head pose over the duration of the EPI-BOLD scan, and used to train a predictive model to estimate head pose changes from the video data. Model performance was quantified by assessing the coefficient of determination (R²). We evaluated the utility of our technique by assessing the relationship between video-based head pose changes during structural MRI and (i) vertex-wise cortical thickness and (ii) subcortical volume estimates.

RESULTS

Video-based head pose estimates were significantly correlated with ground truth head pose changes estimated from EPI-BOLD imaging in a hold-out dataset. We observed a general brain-wide overall reduction in cortical thickness with increased head motion, with some isolated regions showing increased cortical thickness estimates with increased motion. Subcortical volumes were generally reduced in motion affected scans.

CONCLUSIONS

We trained a predictive model to estimate changes in head pose during structural MRI scans using in-scanner eye tracker video. The method is independent of individual image acquisition parameters and does not require markers to be to be fixed to the patient, suggesting it may be well suited to clinical imaging and research environments. Head pose changes estimated using our approach can be used as covariates for morphometric image analyses to improve the neurobiological validity of structural imaging studies of brain development and disease.

Methylphenidate for attention problems in epilepsy patients: Safety and efficacy

Children with attention deficit hyperactivity disorder (ADHD) have an increased risk of seizures, and children with epilepsy have an increased prevalence of ADHD. Adults with epilepsy often have varying degrees of attentional dysfunction due to multiple factors, including anti-seizure medications, frequent seizures, interictal discharges, underlying lesions, and psychiatric comorbidities. Currently, there are no approved medications for the treatment of epilepsy-related attentional dysfunction. Methylphenidate (MPH) is a stimulant, FDA-approved for the treatment of ADHD, and often used for ADHD in the setting of pediatric epilepsy. Large database and registry studies indicate safety of MPH in children with ADHD and epilepsy, with no significant effect on seizure frequency. Small single-dose and open-label studies suggest efficacy of MPH in adults with epilepsy-related attention deficits. Methylphenidate represents a possible treatment for attentional dysfunction due to epilepsy, but large, randomized, placebo-controlled, double-blinded studies are needed.

THE EFFECT OF TUBERCLE BACILLI ON THE POLYMORPHONUCLEAR LEUCOCYTES OF NORMAL ANIMALS

A description is given of a slide cell whereby the rate of migration of very small amounts of leucocytes can be followed and measured. The migration of polymorphonuclear leucocytes was found to be inhibited by virulent tubercle bacilli pathogenic for the class of animal (mammal or bird) from which the leucocytes were obtained; it was not affected by the avirulent variants of these microorganisms, or by bacilli pathogenic for animals of the other class. Tests failed to disclose that the inhibition of leucocytic migration resulted from any gross damage caused by the bacilli to the leucocytes.

HIV-1 western blot assay: What determines an indeterminate status?

BACKGROUND

The Western blot assay is the gold standard for the detection of antibodies to human immunodeficiency virus type 1 (HIV-1). However, indeterminate Western blot reactivity to HIV-1 proteins may occur in individuals, who may not be infected with HIV.

AIM

This retrospective study was aimed to determine the diagnostic value of the interpretation criteria in relation to commercial kits for HIV-1 diagnosis.

METHODS AND MATERIALS

A total of 556 serum/plasma specimens collected from high-risk population attending our HIV clinic from 2000-2004 were tested by three different western blot kits: NEW LAV BLOT I (n=244), HIV BLOT 2.2; (n=112), Genetic Systems HIV-1 (n=237). And the results of western blot strips were analyzed using the various interpretation criteria: WHO/NACO, CDC/ ASTPHLD, ARC, FDA, CRSS and JHU. Some specimens were run on more than one kit. RT-PCR assay was performed on 5 specimens, which were indeterminate with LAV BLOT I.

RESULTS

The discrepancy in LAV BLOT I positive results were between 157(64)-176(72), and indeterminate results were between 44(18) to 63(25). No such variations were observed in genetic systems. There are some HIV negative (by PCR) specimens were indeterminate in LAV BLOT I revealing the kit more sensitive and less effective for diagnostic purpose.

CONCLUSION

The genetic systems kit is superior to other kits we analyzed and its results are concordant with HIV-1 PCR results. To report, the choice of western blot commercial kit is paramount important than the use of particular interpretation criteria for the diagnosis of HIV-1.

HIV-1 western blot assay: What determines an indeterminate status?

BACKGROUND

The Western blot assay is the gold standard for the detection of antibodies to human immunodeficiency virus type 1 (HIV-1). However, indeterminate Western blot reactivity to HIV-1 proteins may occur in individuals, who may not be infected with HIV.

AIM

This retrospective study was aimed to determine the diagnostic value of the interpretation criteria in relation to commercial kits for HIV-1 diagnosis.

METHODS AND MATERIALS

A total of 556 serum/plasma specimens collected from high-risk population attending our HIV clinic from 2000-2004 were tested by three different western blot kits: NEW LAV BLOT I (n=244), HIV BLOT 2.2; (n=112), Genetic Systems HIV-1 (n=237). And the results of western blot strips were analyzed using the various interpretation criteria: WHO/NACO, CDC/ ASTPHLD, ARC, FDA, CRSS and JHU. Some specimens were run on more than one kit. RT-PCR assay was performed on 5 specimens, which were indeterminate with LAV BLOT I.

RESULTS

The discrepancy in LAV BLOT I positive results were between 157(64)-176(72), and indeterminate results were between 44(18) to 63(25). No such variations were observed in genetic systems. There are some HIV negative (by PCR) specimens were indeterminate in LAV BLOT I revealing the kit more sensitive and less effective for diagnostic purpose.

CONCLUSION

The genetic systems kit is superior to other kits we analyzed and its results are concordant with HIV-1 PCR results. To report, the choice of western blot commercial kit is paramount important than the use of particular interpretation criteria for the diagnosis of HIV-1.

Optimisation of the enzyme-based determination of hydrogen peroxide using the quartz crystal microbalance

The benzidines, 3,3'-diaminobenzidine (DAB), 3,3'-dimethoxybenzidine (DMOB) and 3,3',5,5'-tetramethylbenzidine (TMB) were enzymatically oxidised to detect hydrogen peroxide, using the quartz crystal. The oxidised product mainly remains in suspension, resulting in a limited quartz sensor signal. We have used two non-ionic surfactants, Tween 80 and Triton X-100 to interact with the oxidised amphiphilic products to increase their solubility and surface activity, and their ability to adsorb to the crystal surface. Tween 80 exhibits optimised response effects for DAB, DMOB and TMB at 0.012, 0.005, and 0.002% (v/v), respectively, whereas Triton X-100 is optimum at 0.1, 0.2, and 0.006% (v/v), respectively. As a result, we have improved the quartz crystal sensor sensitivity to peroxide. The use of Triton X-100 gave an improved response time.

Recurrent acute pancreatitis: an algorithmic approach to identification and elimination of inciting factors

Recurrent acute pancreatitis represents a challenging clinical problem associated with significant morbidity, impairment in quality of life, and expense. If unchecked, recurrent episodes of acute pancreatitis may lead to chronic pancreatitis. In this work we have combined the opinion of experts in pancreatology and an extensive review of the literature to develop a logical algorithm that facilitates the stepwise identification and elimination of inciting factors using current technology. The approach taken in recurrent acute pancreatitis is clearly dependent on adequate and appropriate evaluation and treatment of the patient with an initial episode of acute pancreatitis. Future advances in the treatment of these patients will almost certainly depend on improved imaging modalities, prospective clinical trials assessing the efficacy of endoscopic and surgical intervention, a better understanding of mutations and pathophysiologic mechanisms responsible for recurrent acute pancreatitis, and the development of novel, effective preventive and therapeutic strategies.

Diverging fertility among U.S. women who delay childbearing past age 30

In this paper I examine the evolving association between educational attainment and the timing of births. In the late 1970s, women with four-year college degrees had lower first birth rates before age 30 than women with less education, but rates of first births were similar for the two groups after age 30. From the 1970s to the 1990s, first birth rates decreased before age 30 for all women, but increased after age 30 only for women with four-year college degrees. Parity 2 birth rates also increased for college graduates with a first birth after age 30. These results document widening educational differences in fertility timing between 1975 and 1995, which may reflect period changes at later ages in women's work and family lives.

Pancreatic cancer surveillance in a high-risk cohort. Is it worth the cost?

Pancreatic adenocarcinoma is the 10th most common malignancy and 4th largest cancer killer in adults. Earlier tumor detection through screening of high risk groups, presumably to increase the percentage of cases resectable for cure in these cohorts, has emerged as a prominent strategy to combat this disease. This article examines the feasibility of this strategy in patients with hereditary pancreatic cancer (HPC) and hereditary pancreatitis (HP). Because of a variety of factors, specific cost projections for screening with HPC kindreds are problematic at best. Patients with HP exhibit a 53-fold increased risk of pancreatic cancer, with a cumulative risk of 40% by age 70. The authors discuss the modalities available to screen this cohort and subsequently perform a theoretical cost analysis. The authors' findings suggest that screening has the potential to be cost-effective only in hereditary pancreatitis patients = 50 years-of-age. The most cost-effective option will likely combine an initial serologic test with high sensitivity and a subsequent serologic or pancreatic juice test with sufficient specificity to act as a "gatekeeper" to imaging with endoscopic ultrasound (EUS). Banking of blood and pancreatic juice samples should be mandatory in any screening protocol. The lower tumor yield in other high-risk groups (e.g., non-hereditary chronic pancreatitis) will effectively preclude the use of such screening protocols. The vast majority of patients will continue to present with unresectable disease.

Endoscopic retrograde cholangiopancreatography in the diagnosis and management of pancreatic diseases

Endoscopic retrograde cholangiopancreatography (ERCP) has been used for diagnosis and treatment of pancreatic diseases for over 20 years. ERCP has been most intensely investigated for acute biliary pancreatitis. Randomized trials have proven that its use will decrease morbidity and have suggested a decrease in mortality for patients with severe gallstone pancreatitis. ERCP is also valuable in detecting and treating main pancreatic duct leaks with transpapillary stenting. Symptomatic pseudocysts, which may be seen in either acute or chronic pancreatitis, can be drained via the papilla or through creation of a cystogastrostomy or cystoduodenostomy with a needle-knife sphincterotome. Endoscopic treatment of patients with recurrent acute pancreatitis presumed due to pancreas divisum and sphincter of Oddi dysfunction remains controversial. Dominant pancreatic strictures or calculi in the setting of chronic pancreatitis may be treated with stenting and removal of calculi to improve abdominal pain. Finally, diagnosis of pancreatic cancer by brush cytology and palliative management of biliary obstruction with various plastic and expandable metal sents have simplified management of this difficult problem.

Use of omeprazole in the management of giant duodenal ulcer: results of a prospective study

BACKGROUND

Giant duodenal ulcer (GDU) is generally thought to require surgical intervention. Proton pump inhibitors have beneficial effects in peptic ulcer disease, but their role in GDU disease is unknown. We examined the use of omeprazole in GDU management.

METHODS

Twenty-eight patients were diagnosed with GDU. One patient required immediate operative intervention. The remaining 27 were placed on omeprazole (40 mg daily). When ulcer healing was documented by endoscopy, the patients were placed on oral histamine-2 receptor antagonist therapy.

RESULTS

Of the 28 study patients, 20 (71.4%) did not require operative intervention, and 8 (28.6%) required operation for ulcer complications. Of the 15 patients with adherent clot or a visible vessel at initial endoscopy, 7 (46.7%) required operative intervention, as compared with 1 (7.7%) of the 13 patients without a visible vessel or adherent clot. This difference was statistically significant (P < .05). Twenty-three patients underwent antral biopsy and/or enzyme-linked immunosorbent assay for Helicobacter pylori, and 9 (39.1%) had a positive result.

CONCLUSIONS

Omeprazole is effective in the treatment of GDU disease. An adherent clot or a visible vessel at endoscopy indicates a higher likelihood of complications requiring operation. The relatively low H pylori infection rate, as compared with other peptic ulcer disease, may indicate a different pathophysiology in GDU.

Pancreatic disease in the elderly

This article reviews age-related alterations in pancreatic structure and function and provides an update of advances in clinical understanding of the epidemiology, pathogenesis, and pathophysiology of acute pancreatitis, chronic pancreatitis, and pancreatic adenocarcinoma. This article also provides guidelines for the integration of recent radiologic, endoscopic, surgical, and oncologic advances in these areas into the current clinical practice of the gerontologist and gastroenterologist.

Hereditary pancreatitis and pancreatic carcinoma

Few risk factors for pancreatic cancer have emerged except for chronic pancreatitis. Recently, hereditary pancreatitis was estimated to carry a standardized incidence ratio of 53, a risk about 25 times higher than smoking. A review of the ongoing hereditary pancreatitis study of the Midwest Multicenter Pancreatic Study Group suggests that the risk of pancreatic cancer is related to long-standing pancreatitis rather than to the cationic trypsinogen mutations. No recommendations can be made on screening patients with hereditary pancreatitis for pancreatic cancer at this time. However, prospective data, serum, and pancreatic juice should be collected and banked on consenting patients at risk as part of prospective, multicenter trials so that evidence-based recommendations for hereditary pancreatitis and other types of chronic pancreatitis can be made in the future.

Endoscopic pancreatic duct stenting to treat pancreatic ascites

BACKGROUND

Management of pancreatic ascites with conservative medical therapy or surgery has met with limited success. Decompression of the pancreatic ductal system through transpapillary stent placement, an alternative strategy, has been reported in only a handful of cases of pancreatic ascites.

METHODS

We reviewed all cases from 1994 to 1997 in which patients with pancreatic ascites underwent an endoscopic retrograde pancreatogram documenting pancreatic duct disruption with subsequent placement of a transpapillary pancreatic duct stent. Clinical end points were resolution of ascites and need for surgery.

RESULTS

There were 8 cases of pancreatic ascites in which a 5F or 7F transpapillary pancreatic duct stent was placed as the initial drainage procedure. Pancreatic ascites resolved in 7 of 8 patients (88%) within 6 weeks. Ascites resolved in the eighth patient, a poor candidate for surgery, following placement of a 5 mm expandable metallic pancreatic stent. No infections, alterations in ductal morphology, or other complications related to stent placement were noted. There was no recurrence of pancreatic ascites or duct disruption at a mean follow-up of 14 months.

CONCLUSIONS

Our experience doubles the number of reported cases in which transpapillary pancreatic stent placement safely obviated the need for surgical intervention in the setting of pancreatic ascites. This therapeutic endoscopic intervention should be seriously considered in the initial management of patients with pancreatic ascites.

Prevalence and predictors of severe acute pancreatitis in patients with acquired immune deficiency syndrome (AIDS)

OBJECTIVE

Recent case control data suggested that a severe course of acute pancreatitis in HIV+ patients was 1) common (50% of cases), 2) poorly predicted by Ranson's criteria (sensitivity 41%), and 3) accurately predicted by a diagnosis of AIDS (positive predictive value 67%). However, the definition of severity included length of stay in hospital and excluded commonly accepted markers (local complications, systemic complications, and need for surgery). The aim of this study was to determine 1) the prevalence of severity and 2) the value of these predictors with regard to severity, as defined by commonly accepted standardized criteria in patients with AIDS and acute pancreatitis.

METHODS

A retrospective review identified 50 patients with AIDS exhibiting clinical, laboratory, and/or radiological features of acute pancreatitis.

RESULTS

Only five patients followed a severe course as defined by accepted markers. Of these patients, 29 had values available for at least nine of 11 of Ranson's criteria (sensitivity 80%, specificity 54%). Points were awarded most commonly for decreased serum Ca2+ (n = 14) and elevated serum LDH (n = 7).

CONCLUSIONS

In patients with AIDS and acute pancreatitis at our institutions, 1) the prevalence of severity and 2) the sensitivity of Ranson's criteria with regard to severity is comparable to that reported in large historical case series of immunocompetent patients. Pseudohypocalcemia and/or elevation in LDH are frequent, likely due to the catabolic infectious disease state.

Peripherally inserted central catheters revisited

BACKGROUND

This study compares central venous catheters (CVC) and peripherally inserted central catheters (PICC) for indications for insertion, complications, and economic impact.

METHODS

A retrospective review of 838 (283 CVC, 555 PICC) consecutively placed venous catheters reflected 49,365 CVC and 11,814 PICC days.

RESULTS

There were 57 (20%) complications in the CVC group, 197 (35%) complications in the PICC group. PICC were associated with a statistically significant increase in the incidence of catheter malfunction (P = 0.0005), arm vein phlebitis (P = 0.0004), and overall complications (P = 0.00001). A higher complication rate was noted in PICC inserted for chemotherapy (P = 0.00001) and parenteral hyperalimentation administration (P = 0.04). Charges for inpatient insertion of PICC and CVC were $500 and $2,500, respectively.

CONCLUSIONS

PICC have a significantly higher complication rate than CVC. PICC provide cost-effective central access of 2 to 3 weeks' duration, reserving operatively placed CVC for longer access requirements.

Clinical characteristics of hereditary pancreatitis in a large family, based on high-risk haplotype. The Midwest Multicenter Pancreatic Study Group (MMPSG)

OBJECTIVES

Because there are no markers for hereditary pancreatitis (HP), diagnosis has relied on clinical features and inferences. Identification of the HP disease gene locus on chromosome 7q35 provides the first genetic marker for HP, allowing an accurate comparison of the clinical diagnosis of HP with the presence of a high-risk HP haplotype. Our objectives were to compare the clinical diagnosis of HP with inheritance of the HP gene and to characterize the common clinical features.

METHODS

A detailed questionnaire was administered to 102 study participants of a large HP kindred. Blood samples were taken for DNA extraction and high-risk haplotype determination. Clinical findings were compared with the presence of a high-risk haplotype.

RESULTS

A family tree of more than 500 members and eight generations was constructed, and clinical features of the 102 participants were determined. HP occurred before the age of 5 yr in 58% of subjects, who presented with common symptoms of abdominal pain, nausea/vomiting, and frequent attacks. Thirty-five probands, of whom 80% had clinical symptoms, carried the high-risk haplotype, confirming previous estimates of 80% penetrance. Thirty-two of the study participants had been clinically diagnosed with HP, whereas 70 were clinically unaffected. With regard to the presence of the high-risk haplotype, 87.5% of the clinically diagnosed patients were affected by HP (true positive), whereas 12.5% did not carry the high-risk haplotype (false positive). Seven obligate carriers were identified through DNA analysis; three had previously been unrecognized because of lack of affected offspring.

CONCLUSIONS

The diagnosis of hereditary pancreatitis on clinical grounds alone may be inaccurate in less severe cases, as is the exclusion of carrier status through family tree analysis. Therefore, a definitive diagnosis of hereditary pancreatitis in equivocal cases or exclusion of a carrier state should include analysis of genetic markers.

Hereditary pancreatitis is caused by a mutation in the cationic trypsinogen gene

Hereditary pancreatitis (HP) is a rare, early-onset genetic disorder characterized by epigastric pain and often more serious complications. We now report that an Arg-His substitution at residue 117 of the cationic trypsinogen gene is associated with the HP phenotype. This mutation was observed in all HP affected individuals and obligate carriers from five kindreds, but not in individuals who married into the families nor in 140 unrelated individuals. X-ray crystal structure analysis, molecular modelling, and protein digest data indicate that the Arg 117 residue is a trypsin-sensitive site. Cleavage at this site is probably part of a fail-safe mechanism by which trypsin, which is activated within the pancreas, may be inactivated; loss of this cleavage site would permit autodigestion resulting in pancreatitis.

A gene for hereditary pancreatitis maps to chromosome 7q35

BACKGROUND & AIMS

Hereditary pancreatitis (HP) is an autosomal-dominant disorder with incomplete penetrance characterized by recurrent bouts of severe epigastric pain with onset usually at 5-10 years of age. A genetic linkage study was designed to identify the HP gene.

METHODS

A 500-member pedigree was constructed from a U.S. kindred centered in eastern Kentucky and western Virginia. A genome-wide search strategy was employed using a 36-member subset of this family to determine the genetic locus for HP. Testing for linkage to microsatellite loci was performed at 20-cM intervals.

RESULTS

Linkage was established between the HP phenotype and chromosome 7q in this subset of the family. Modeled as an autosomal dominant disorder with 80% penetrance, a maximal multipoint logarithm of the odds score of 4.3 was obtained using a four-point analysis consisting of markers D7S684, D7S661, D7S505, and the HP locus. Two microsatellite markers, D7S661 and D7S505, that correspond to the 7q35 region of chromosome 7 spanning a 6-cM region did not evidence obligate recombinations with HP. The centromeric and telomeric limits are defined by recombinations at D7S684 and D7S483, respectively, which generates a 19-cM locus for HP. Utilizing family members from the extended pedigree, a break in the high-risk haplotype between D7S684 and D7S661 was observed, which suggests it may be possible to exclude an additional 8 cM from the HP locus. A maximal pairwise logarithm of the odds score of 4.73 at a recombination fraction of theta at D7S684 was obtained with the addition of these extended family members.

CONCLUSIONS

Linkage of HP to 7q35 represents a major advancement in our understanding of the genetic basis of this disorder.

Chronic abdominal pain caused by thoracic disc herniation

A patient with 7 yr of severe disabling chronic epigastric abdominal pain attributed to chronic pancreatitis was seen in consultation before a 95% pancreatectomy for pain control. Previous attempts to identify and treat the pain lead to extensive radiographic, pharmacological, endoscopic, and surgical interventions, including a Roux-en-Y pancreaticojejunostomy. Pain control was poor despite implantation of a continuous intrathecal morphine infusion pump. A focused physical examination, however, raised the suspicion of thoracic disc disease, which was confirmed after myelogram with computed tomography. Disruption of the T7-T8 disc with protrusion into the vertebral canal and displacement of the spinal cord with an associated bone spur were identified. A microsurgical thoracic discectomy was performed. Immediately, the pain began resolving, and she was pain free and off her medications within several weeks. To our knowledge, this is the first description of a herniated thoracic disc presenting as the pain of chronic pancreatitis. The diagnosis of thoracic disc syndrome requires a high index of suspicion and should be considered in patients with chronic abdominal pain.

'Diaphragmlike' stricture and ulcer of the colon during diclofenac treatment

Diclofenac sodium is a widely used enteric-coated nonsteroidal anti-inflammatory drug. We describe a woman with Hemoccult-positive stools and iron deficiency anemia who developed both a colonic ulcer and a "diaphragm-like" colonic stricture while taking enteric-coated diclofenac. These lesions were evident on colonoscopy but not on barium studies. Biopsy specimens of the ulcer and stricture revealed particulate matter that was indistinguishable from diclofenac pill fragments by electron microscopy. Discontinuation of diclofenac therapy resulted in resolution of anemia and Hemoccult-positive stools. We conclude that (1) enteric-coated diclofenac is associated with both colonic ulcers and diaphragm-like colonic strictures; (2) the pathophysiologic mechanism for the development of both ulcers and strictures may involve a direct action of diclofenac within these lesions; (3) colonoscopy may be superior to barium studies in evaluating patients receiving diclofenac who have iron deficiency anemia and/or Hemoccult-positive stools.

Effects of dominance rank on d-amphetamine-induced increases in aggression

Previous research has suggested that certain social factors, e.g., dominance rank, can determine the behavioral effects of drugs in individual members of a social group. In the present experiment, the effects of d-amphetamine were studied in two adult male monkeys with dominance rankings that changed during a reorganization of the social hierarchy in a captive group of stumptail macaques (Macaca arctoides). A range of doses of d-amphetamine was administered to each subject, and dose-effect curves were determined before and after group reorganization and stabilization. The data revealed drug effects which were dependent upon dose and the social rank of the animals. When either subject occupied the highest ranking or alpha position within the dominance hierarchy, rate of aggressive behavior initiated by the subject was several times greater than when that monkey occupied a lower position within the dominance hierarchy. Moreover, for either subject, the dose-effect curve was shifted to the right when the monkey was highest in the dominance hierarchy. Finally, aggression initiated by the drug-treated subject was directed more frequently toward adult members of the group when the subject was highest in the hierarchy and toward nonadult animals when the subject was lower in the hierarchy. These data support the hypothesis that the dominance position of an animal in a group can be a determinant of the behavioral effect of certain drugs.