Chronic intestinal pseudo-obstruction. Did you search for lysosomal storage diseases?

Chronic intestinal pseudo-obstruction results in clinical manifestations that resemble intestinal obstruction but in the absence of any physical obstructive process. Fabry disease is an X-linked lysosomal storage disease characterized by the dysfunction of multiple systems, including significant gastrointestinal involvement. We report the occurrence of chronic intestinal pseudo-obstruction in two unrelated patients with Fabry disease and the possible explanation of a direct relation of these two disorders. In Fabry disease, gastrointestinal symptoms occur in approximately 70% of male patients, but the frequency ranges from 19% to 69% in different series. In some patients, colonic dysmotility due glycolipid deposition in autonomic plexus and ganglia can lead to the pseudo-obstruction syndrome, simulating intestinal necrosis. That is why up to this date colostomy has been performed in some cases, even for children with FD without cardiac, renal or cerebrovascular compromise. Early treatment with enzyme replacement therapy in asymptomatic or mildly symptomatic patients may be justified in order to prevent disease progression. Several studies have demonstrated that enzyme replacement therapy alleviates GI manifestations. Because of the non-specific nature of the gastrointestinal symptoms, diagnosis of Fabry disease is often delayed for several years. Gastrointestinal involvement is often misdiagnosed or under-reported. It is therefore very important to consider Fabry disease in the differential diagnosis of chronic intestinal pseudo-obstruction.

Gastrointestinal involvement in Fabry disease. So important, yet often neglected.

Fabry disease is an X-linked metabolic storage disorder due to the deficiency of lysosomal alpha-galactosidase A which causes accumulation of glycosphingolipids, primarily globotriaosylceramide, throughout the body. Gastrointestinal signs and symptoms-abdominal pain, nausea, diarrhea and diverticular disease--are some of the most frequently reported complaints in patients with Fabry disease but are often neglected. Gastrointestinal symptoms are due to intestinal dysmotility as well as impaired autonomic function, vasculopathy and myopathy. Since 2001, enzyme replacement therapy has been a mainstay in treatment of gastrointestinal symptoms of Fabry disease (FD), resulting in reduced gastrointestinal symptoms. Here, we report on four patients with Fabry disease (FD) who manifested early gastrointestinal involvement.

Biochemical and pharmacological characterization of different recombinant acid alpha-glucosidase preparations evaluated for the treatment of Pompe disease.

Pompe disease results in the accumulation of lysosomal glycogen in multiple tissues due to a deficiency of acid alpha-glucosidase (GAA). Enzyme replacement therapy for Pompe disease was recently approved in Europe, the U.S., Canada, and Japan using a recombinant human GAA (Myozyme, alglucosidase alfa) produced in CHO cells (CHO-GAA). During the development of alglucosidase alfa, we examined the in vitro and in vivo properties of CHO cell-derived rhGAA, an rhGAA purified from the milk of transgenic rabbits, as well as an experimental version of rhGAA containing additional mannose-6-phosphate intended to facilitate muscle targeting. Biochemical analyses identified differences in rhGAA N-termini, glycosylation types and binding properties to several carbohydrate receptors. In a mouse model of Pompe disease, glycogen was more efficiently removed from the heart than from skeletal muscle for all enzymes, and overall, the CHO cell-derived rhGAA reduced glycogen to a greater extent than that observed with the other enzymes. The results of these preclinical studies, combined with biochemical characterization data for the three molecules described within, led to the selection of the CHO-GAA for clinical development and registration as the first approved therapy for Pompe disease.

Recombinant human acid [alpha]-glucosidase: major clinical benefits in infantile-onset Pompe disease.

BACKGROUND: Pompe disease is a progressive metabolic neuromuscular disorder resulting from deficiency of lysosomal acid alpha-glucosidase (GAA). Infantile-onset Pompe disease is characterized by cardiomyopathy, respiratory and skeletal muscle weakness, and early death. The safety and efficacy of recombinant human (rh) GAA were evaluated in 18 patients with rapidly progressing infantile-onset Pompe disease. METHODS: Patients were diagnosed at 6 months of age and younger and exhibited severe GAA deficiency and cardiomyopathy. Patients received IV infusions of rhGAA at 20 mg/kg (n = 9) or 40 mg/kg (n = 9) every other week. Analyses were performed 52 weeks after the last patient was randomized to treatment. RESULTS: All patients (100%) survived to 18 months of age. A Cox proportional hazards analysis demonstrated that treatment reduced the risk of death by 99%, reduced the risk of death or invasive ventilation by 92%, and reduced the risk of death or any type of ventilation by 88%, as compared to an untreated historical control group. There was no clear advantage of the 40-mg/kg dose with regard to efficacy. Eleven of the 18 patients experienced 164 infusion-associated reactions; all were mild or moderate in intensity. CONCLUSIONS: Recombinant human acid alpha-glucosidase is safe and effective for treatment of infantile-onset Pompe disease. Eleven patients experienced adverse events related to treatment, but none discontinued. The young age at which these patients initiated therapy may have contributed to their improved response compared to previous trials with recombinant human acid alpha-glucosidase in which patients were older.

Enzyme replacement therapy in the mouse model of Pompe disease.

Deficiency of acid alpha-glucosidase (GAA) results in widespread cellular deposition of lysosomal glycogen manifesting as myopathy and cardiomyopathy. When GAA-/- mice were treated with rhGAA (20 mg/kg/week for up to 5 months), skeletal muscle cells took up little enzyme compared to liver and heart. Glycogen reduction was less than 50%, and some fibers showed little or no glycogen clearance. A dose of 100 mg/kg/week resulted in approximately 75% glycogen clearance in skeletal muscle. The enzyme reduced cardiac glycogen to undetectable levels at either dose. Skeletal muscle fibers with residual glycogen showed immunoreactivity for LAMP-1/LAMP-2, indicating that undigested glycogen remained in proliferating lysosomes. Glycogen clearance was more pronounced in type 1 fibers, and histochemical analysis suggested an increased mannose-6-phosphate receptor immunoreactivity in these fibers. Differential transport of enzyme into lysosomes may explain the strikingly uneven pattern of glycogen removal. Autophagic vacuoles, a feature of both the mouse model and the human disease, persisted despite glycogen clearance. In some groups a modest glycogen reduction was accompanied by improved muscle strength. These studies suggest that enzyme replacement therapy, although at much higher doses than in other lysosomal diseases, has the potential to reverse cardiac pathology and to reduce the glycogen level in skeletal muscle.

Proper coronary vascular development and heart morphogenesis depend on interaction of GATA-4 with FOG cofactors.

GATA-family transcription factors are critical to the development of diverse tissues. In particular, GATA-4 has been implicated in formation of the vertebrate heart. As the mouse Gata-4 knock-out is early embryonic lethal because of a defect in ventral morphogenesis, the in vivo function of this factor in heart development remains unresolved. To search for a requirement for Gata4 in heart development, we created mice harboring a single amino acid replacement in GATA-4 that impairs its physical interaction with its presumptive cardiac cofactor FOG-2. Gata4(ki/ki) mice die just after embryonic day (E) 12.5 exhibiting features in common with Fog2(-/-) embryos as well as additional semilunar cardiac valve defects and a double-outlet right ventricle. These findings establish an intrinsic requirement for GATA-4 in heart development. We also infer that GATA-4 function is dependent on interaction with FOG-2 and, very likely, an additional FOG protein for distinct aspects of heart formation.

Polypoid dysplasia in Barrett's esophagus: a clinicopathologic, immunohistochemical, and molecular study of five cases.

Dysplasia in Barrett's esophagus (BE) is a precursor to adenocarcinoma and most commonly occurs as a flat, grossly undetectable lesion. Rarely, dysplasia in BE may grow as a polypoid lesion. Most BE-associated polypoid dysplastic lesions have been referred to as "adenomas" because of their histological similarity to a colonic adenoma. BE-associated polypoid dysplastic lesions have been less well characterized than the flat type. Therefore, our aim was to characterize the clinicopathologic and molecular features of five cases of BE-associated polypoid dysplasia and to review the literature on this entity. The cases were evaluated clinically, histologically, immunostained for MIB-1 and p53, and genotyped for loss of heterozygosity (LOH) at the adenomatous polyposis coli (APC) locus. Mucosal biopsy specimens of five BE patients without dysplasia, and five BE cases with high-grade flat dysplasia, were used as controls. The study patients were all male (average age, 71 years) who presented with symptoms of gastroesophageal reflux disease. Endoscopically, all five cases had a well-defined sessile or pedunculated polypoid lesion ranging from 0.4 to 1.5 cm in size in the mid (n = 1) or distal (n = 4) esophagus and were associated with specialized-type BE (four long segment, one short segment). Histologically, the polyps consisted of intestinalized epithelium with low- and high-grade dysplasia. All five cases contained adenocarcinoma (four within the polyp, one in adjacent BE). All polyps showed increased cell proliferation in the form of surface MiB-1 staining and showed positive p53 staining. Three of three (100%) informative cases showed LOH at the APC locus in the dysplastic epithelium and in areas of adenocarcinoma. All five flat dysplasia controls also showed surface MIB-1 staining and p53 positivity, and three of three informative controls showed LOH for APC. None of the nondysplastic BE controls showed any of these findings. Three patients were treated with esophagectomy and two with polypectomy. All were alive, without metastasis, from 2 months to 6 years later. A literature review of esophageal "adenomas" uncovered 12 cases. Four of these had no clinical or pathological information, two were, in fact, gastric heterotopic lesions, one was composed entirely of intestinal-type epithelium, and five were polypoid dysplastic lesions similar to the cases described here (three male, two female; mean age, 59 years). Four of these five cases were associated with adenocarcinoma in the polyp (two intramucosal, two submucosal). In summary, BE-associated polypoid dysplasia share similar clinical, pathological, and molecular features as flat dysplasia and are often associated with adenocarcinoma. Thus, we agree with other authors who recommend that the term adenoma, which usually carries a benign connotation, be abandoned in favor of a descriptive diagnostic term, such as "BE-associated polypoid dysplasia." BE patients with this lesion should be considered strong candidates for esophageal resection similar to lesions of this kind that occur in inflammatory bowel disease.

The nuclear factor-kappa B/inhibitor of kappa B autoregulatory system and atherosclerosis.

Nuclear factor-kappa B is a ubiquitous transcription factor that can be activated by diverse proatherogenic stimuli such as inflammatory cytokines, lipopolysaccharide, oxidant stress and physical forces. Recently, there have been major advances in understanding signal transduction from the tumor necrosis factor receptor, a model activator of the nuclear factor-kappa B system. One set of signals from the receptor initiates a phosphorylation cascade resulting in the activation of a kinase complex which phosphorylates an inhibitor of nuclear factor-kappa B, or inhibitor of kappa B. Degradation of the inhibitor occurs in parallel with activation and nuclear accumulation of the transcription factor. Subsequent changes in gene expression induce the production of multiple cytokines and adhesion molecules, which are important in early atherosclerotic lesion formation, and generation of survival signals, which could be important in lesion progression. A second set of signals from the tumor necrosis factor receptor leads to cell death. Understanding these competing pathways in vascular cells may help to clarify the role of this transcription factor in the proliferative lesions of atherogenesis.

Sequential ciprofloxacin therapy in pediatric cystic fibrosis: comparative study vs. ceftazidime/tobramycin in the treatment of acute pulmonary exacerbations. The Cystic Fibrosis Study Group.

BACKGROUND: Cystic fibrosis patients have chronic bacterial infections of the respiratory tract, most commonly Pseudomonas aeruginosa. Although controversial, administration of antibiotic therapy during acute pulmonary exacerbations is standard practice. Fluoroquinolones are currently not indicated for use in young children because of the observation of arthropathy and damage to growing cartilage in beagle puppies. Because of its activity against P. aeruginosa and excellent oral bioavailability, ciprofloxacin offers a unique therapeutic alternative for this patient population. OBJECTIVE: This prospective, randomized, double blind study compared the efficacy and safety of sequential intravenous/oral ciprofloxacin vs. ceftazidime/tobramycin in hospitalized pediatric cystic fibrosis patients with an acute pulmonary exacerbation associated with P. aeruginosa infection. METHODS: One hundred thirty patients (ages 5 to 17 years) were randomized to receive either i.v. ciprofloxacin 10 mg/kg every 8 h for 7 days followed by oral ciprofloxacin 20 mg/kg every 12 h for a minimum of 3 days or i.v. ceftazidime 50 mg/kg every 8 h plus i.v. tobramycin 3 mg/kg every 8 h for a minimum of 10 days. Clinical, bacteriologic and safety responses were assessed throughout the study. RESULTS: All 84 patients (median age, 11 years; range, 5 to 17 years) valid for efficacy in both treatment groups demonstrated clinical improvement. Five patients experienced clinical relapses (3 ciprofloxacin, 2 ceftazidime/tobramycin) by the 2- to 4-week follow-up. Intent-to-treat analysis demonstrated similar clinical findings between the two treatment groups at both the end of therapy and follow-up. Clinical improvement correlated with improvement in pulmonary function studies and the acute clinical scoring system but not with bacteriologic eradication of Pseudomonas. DNA profiles demonstrated that irrespective of colony morphology, usually one clonal strain was associated with each patient's pulmonary exacerbation. Treatment-associated musculoskeletal events occurred with equal frequency (22% vs. 21%) in both study drug groups (n = 129), and arthralgias were within the range of rates for cystic fibrosis arthropathy. None of these events required study drug discontinuation. CONCLUSION: Sequential i.v./oral ciprofloxacin monotherapy offers a safe and efficacious alternative to standard parenteral therapy for acute pulmonary exacerbations in pediatric cystic fibrosis patients.

Lipoprotein association of human apolipoprotein E/A-I chimeras. Expression in transfected hepatoma cells.

Both apolipoprotein (apo) E and apoA-I are associated with lipoproteins, although with different particle classes. ApoE is associated with very low density lipoprotein (VLDL) and with the larger high density lipoprotein (HDL) subspecies, while apoA-I is found predominantly in association with most HDL subclasses. The genes encoding these proteins have a similar overall structure with the nucleotide sequences of the third and fourth exons coding for the mature protein. In an effort to understand the difference in lipoprotein association patterns of these two apoproteins, we have constructed and expressed chimeric apoproteins using cDNAs in which the third (n) and fourth (c) exons of human apoE and apoA-I are exchanged. McArdle rat hepatoma cells (McA-RH7777), which secrete VLDL- and HDL-like particles, were stably transfected with these cDNAs, and the cDNAs for human apoE and human apoA-I. Single spin NaBr gradient fractions of lipoprotein deficient serum-treated cell medium from transfected McA-RH7777 cells were analyzed. The distributions of transfected human apoE and apoA-I and endogenous rat apoE and apoA-I were compared with those of the chimeras. Among HDL subspecies, human apoE expressed by these cells is associated with particles of density 1.108 g/ml. Similarly, chimera apoA-InEc (exon 3 of apoA-I and exon 4 of apoE) is found in particles of density 1.111 g/ml. Human apoA-I, however, distributes in a broader range of particles with peak densities of 1.111 g/ml and 1.164 g/ml. The distribution of the complementary chimera, apoEnA-Ic, follows this same pattern, with peak particle densities of 1.098 and 1.137 g/ml. This is in contrast to the narrow distributions of endogenous rat apoE and apoA-I, which were found in particles of density 1.099 and 1.089 g/ml, respectively. When metabolically labeled medium was fractionated via gel filtration column chromatography, apoA-InEc was found to associate with the VLDL fractions; apoEnA-Ic was absent from these same fractions. These results suggest that the fourth exon largely determines the distinctive lipoprotein distribution patterns of these two human apoproteins and that the human apoA-I fourth exon sequence may account for the polydisperse HDL pattern as observed by others in transgenic mice expressing human apoA-I.

Epidemiologic analysis and genotypic characterization of a nosocomial outbreak of vancomycin-resistant enterococci.

We are reporting on a nosocomial outbreak of 213 cases of vancomycin-resistant enterococcus infection involving 2,812 enterococcal isolates from patients over a period of 36 months. In 1990, the Enterococcus faecium vancomycin susceptibility rate was found to be 85.7% (36 of 42 cases), and an incidence of 10.9% (42 of 383) was noted. The 1991 data showed E. faecium with a vancomycin susceptibility rate of 61.8% (110 of 178) and an incidence of 26.0% (178 of 684). Subsequently, in 1992, the incidence of E. faecium increased to 34.0% (599 of 1,745), with a decreased vancomycin susceptibility rate of 25.8% (155 of 599). The E. faecalis vancomycin susceptibility rate remained near 97% (1,768 of 1,823) over the 36-month period. Of 115 vancomycin-resistant enterococcus (VRE) clinical isolates identified by the MicroScan MIC Combo-6 panels (Baxter Healthcare, Sacramento, Calif.), the agar dilution method indicated the resistance rate to be 92.3% (106 of 115) (high level), 3.5% (4 of 115) midlevel, and 3.5% (4 of 115) (low level). Genotypic characterization of 32 different VRE isolates by field-inversion gel electrophoresis demonstrated 19 dissimilar restriction endonuclease patterns, with 9 patterns associated with VRE quinolone resistance. Statistical analysis of case-control data for 32 patients with VRE infections indicated a positive association with intrabdominal surgical procedures (odds ratio, 24.12), multidrug therapy (odds ratio, 37.80), preexposure to vancomycin (odds ratio, 20.21), and death (odds ratio, 17.50).