Achalasia: Treatment options revisited. COMPARATIVE STUDIES

Despite the abundance of literature on management of acha- lasia, there appears to be a relative paucity of prospective, randomized controlled studies that directly compare differ­ent treatment modalities. Until recently, there have only been two really effective methods of treating patients with achalasia: forceful dilation and surgery. Data from uncon­trolled retrospective trials have, in general,…

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Achalasia: Treatment options revisited. DRUG THERAPY

Nitrates and calcium channel antagonists have been recom­mended for treatment of achalasia. The rationale behind the use of these medications is their potential to decrease LES tone by relaxing gastrointestinal smooth muscle. However, the limitations in the use of these drugs are several: they are short acting; they can have significant side effects such as…

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Achalasia: Treatment options revisited

Figure 1) Lower esophageal sphincter

Achalasia was one of the first gastrointestinal motility disorders to be characterized, both clinically and manometrically. Failure of relaxation of the lower esophag- eal sphincter (LES) is the cardinal feature of this disease, thought to result from a relatively selective degeneration of the inhibitory neurons in the surrounding myenteric plexus (Figure 1). This leads to…

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Parathyroid tumorigenesis: Genetic abnormalities in sporadic parathyroid carcinoma

Parathyroid tumorigenesis: Genetic abnormalities in sporadic parathyroid carcinoma

Parathyroid carcinoma is usually associated with more severe clinical manifestations of PHPT than parathyroid adenomas. The incidence of parathyroid cancer does not favor women but is matched between the sexes, and the age of onset is approx­imately earlier than in benign disease (mid-40yr instead of the mid-50yr). The principal histological features of parathyroid car­cinoma include…

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Parathyroid tumorigenesis: Genetic abnormalities in sporadic parathyroid adenomas

Figure 4 - Schematic diagram illustrating

To date cyclin D1/parathyroid adenomatosis gene 1 (PRAD1) together with the MEN1 is the only gene with an established role in the development of sporadic (nonfamilial) parathyroid adenomas. The cyclin D1/parathyroid adenomatosis gene 1 oncogene The cyclin D1/PRAD1 gene was identified as a parathyroid oncogene on chromosome 11 q13, clonally activated in a sub­set of…

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Parathyroid tumorigenesis: Familial isolated hyperparathyroidism

FIHP is a clinically defined entity, based on the absence of ex­pression of the extra-parathyroid manifestations that character­ize other familial HPT syndromes. FIHP is genetically hetero­geneous, and can be caused by variant expressions of germline mutations in MEN1, HRPT2, CASR, and probably other genes. One of the puzzling aspects of FIHP is the absence of…

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Parathyroid tumorigenesis: Multiple endocrine neoplasia type 2 A

Figure 3 - Loss of heterozygosity

Germline gain-of-function mutations in the RET protooncogene cause MEN 2A. The RET protein is a receptor tyrosine ki­nase that normally transduces growth and differentiation sig­nals in developing tissues including those derived from the neural crest. This makes the RET gene, which encodes a tyro­sine kinase receptor, a candidate gene involved in nonfamilial hyperparathyroidism. There are…

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