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Hunter syndrome

Hunter's syndrome is a mucopolysaccharide disease caused by an enzyme deficiency of iduronate-2-sulfatase (I2S). This is also called as mucopolysaccharoidosis Type II. It was first described by Scottish physician Charles A. Hunter (1873-1955) in 1917. more...

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Definition

Hunter syndrome is a hereditary disease in which the breakdown of a mucopolysaccharide (a chemical that is widely distributed in the body outside of cells) is defective. This chemical builds up and causes a characteristic facial appearance, abnormal function of multiple organs, and in severe cases, early death.

Causes, incidence, and risk factors

Hunter syndrome is inherited as an X-linked recessive disease. This means that women carry the disease and can pass it on to their sons, but are not themselves affected.

Because girls have two X chromosomes, their normal X can provide a functioning gene even if their other X is defective. But because boys have an X and a Y, there is no normal X gene to fix the problem if the X is defective.

The metabolic abnormality that causes Hunter syndrome is a lack of the enzyme iduronate-2-sulfatase. In its absence, mucopolysaccharides collect in various body tissues, causing damage.

Affected children may develop an early-onset type (severe form) shortly after age 2 that causes a large skull, coarse facial features, profound mental retardation, spasticity, aggressive behavior, joint stiffness and death before age 20. A late-onset type (mild form) causes later and less severe symptoms.

Symptoms

Juvenile form (early-onset, severe form):

  • mental deterioration
  • severe to profound mental retardation
  • aggressive behavior
  • hyperactivity
  • short stature


Late (mild form):

  • mild to no mental retardation

Both forms:

  • coarse facial features
  • large head (macrocephaly)
  • stiffening of joints
  • increased hair (hypertrichosis)
  • deafness (progressive)
  • enlargement of internal organs such as liver and spleen
  • cardiovascular problems, especially valvular dysfunction
  • abnormal retina (back of the eye)
  • carpal tunnel syndrome

Signs and tests

Signs of the disorder that the doctor might look for include:

  • hepatomegaly (enlargement of liver)
  • splenomegaly (enlargement of spleen)
  • inguinal hernia
  • spasticity
  • heart murmur and heart valve dysfunction
  • joint contractures
  • excretion of heparan sulfate and dermatan sulfate in urine
  • decreased iduronate sulfatase enzyme activity in serum or cells

Tests that may indicate this disorder is present include:

  • urine for heparan sulfate and dermatan sulfate
  • enzyme study, decreased iduronosulfate sulfatase (may be studied in serum, white blood cells and fibroblasts)
  • genetic testing may show mutation in the iduronate sulfatase gene

Read more at Wikipedia.org


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Harrison takes the throttle at CN - Rail Update - Hunter Harrison
From Railway Age, 1/1/03

Canadian National Executive Vice President and Chief Operating Officer E. Hunter Harrison became president and CEO of CN on Jan. 1. He replaced Paul M. Tellier, who left CN after 10 years to become president and CEO of Bombardier, Inc.

"I am deeply honored to have the opportunity to head the best railroad on the continent," said Harrison. "As president and CEO of CN, my priorities will remain a passion for service, efficiency, and innovation to drive market share gains, sustained profitable growth, and greater shareholder value." Harrison will be based at CN headquarters in Montreal.

"CN's board of directors is delighted to announce Hunter Harrison's appointment," said CN Chairman David G. A. McLean. "Hunter is the best operating executive in the rail business, the man who designed and implemented the scheduled railroad at CN. The industry recognizes Hunter's leadership and innovation--Railway Age magazine in January named him 2002 Railroader of The Year." In the magazine's January 2002 issue, Editor William C. Vantuono dubbed Harrison "the master of scheduled railroading."

Harrison, 58, began his railroad career in 1964 as a carman/oiler with the Sr. Louis-San Francisco Railroad while attending school in Memphis, Tenn. Following the merger of the Frisco and Burlington Northern, Harrison held a number of executive positions in transportation/operations. He joined the Illinois Central in 1989 as vice president and COO, and was named senior vice president-transportation in 1991 and senior vice president-operations in July 1992. He implemented scheduled railroading on the IC, a practice that enabled the railroad to consistently post the industry's lowest operating ratio through the mid-1990s.

Harrison was named IC's president and CEO in 1993. In 1998, when CN acquired IC, he was asked by Paul Tellier to become executive vice president and COO of the combined company.

During a press conference announcing his appointment, Harrison said that he had no immediate plans to bring in a new chief operating officer. "It was a new position in 1998," he said. "I want to play on my strengths of running the railroad on a day-to-day basis. I'll stay actively involved in operations while taking on other areas. We have a strong management team, and I'm comfortable with it." He said that CN will sell off its offshore holdings (English, Welsh & Scottish and New Zealand's Tranzrail) over time. He also said he expected further Class I mergers to occur over the next three to five years, though he did not speculate on what railroads would be involved.

Harrison will be presiding over a 2003 capital plan of approximately CS1 billion. New freight cars are part of that program. Last month, CN, the largest carrier of forest products in North America, said it will acquire 350 new boxcars and 200 new center-beam flat cars this year. The high-cube, 50-foot boxcars will be used for newsprint and fine papers. CN will build 100 of the boxcars at its Transcona Shops in Winnipeg, the first such construction program in decades. The remaining 250 will be built by Trinity. The 73-foot, 286,000-pound GRL centerbeam cars, which will be used for lumber, will be built by Greenbrier at its TrentonWorks plant in Nova Scotia.

Prior to Harrison's appointment, CN said it would reduce its work force by 1,146 permanent positions "in a renewed drive to improve productivity." Roughly 30% of the reductions will be achieved through normal attrition and retirement, 45% by way of early retirement, and 25% through severance packages. The reductions "will occur in every corporate and operating function," about two-thirds in Canada, with the remainder in the U.S. In connection with this initiative, CN said it expected to take a fourth-quarter 2002 after-tax work force adjustment charge of approximately $79 million for severance and other payments to affected employees.

CN also said it is adopting an actuarial-based methodology to determine its provision for U.S. personal injury and other' claims, including those for hearing loss, carpal tunnel syndrome, and asbestos-related disease. Under an actuarial-based approach, the cost of employee injuries and other claims will be charged to expenses based on an actuarial estimate of the ultimate cost and number of incidents in each year. Where unasserted claims "can be estimated and considered probable," CN will also record a liability. As a result, CN expected to take an after-tax charge of approximately $173 million in the fourth quarter, approximately two-thirds of that for asbestos-related claims.

"The new methodology for determining our provision for Federal Employers' Liability Act (FELA) and other claims is consistent with current U.S. rail industry practice," said CN. "The change reflects CN's growing presence in the U.S., where the rail industry is uniquely susceptible to litigation involving employee work-related injuries and occupational claims because of FELA, an outmoded law passed in 1908 that applies to railroads. CN is faced with a rising number of personal injury claims in the U.S., and we want to reflect our expected liability in a consistent and forthright manner."

CN said that, together, the two charges will have an after-tax effect on its fourth-quarter 2002 financial results of approximately $252 million.

Paul Tellier xvas Railway Age's 1997 Railroader of the Year. The magazine's late Senior Editor, Gus Welty, wrote in the January 1997 issue that Tellier "took over a notorious under-achiever, a property that had been government-owned for more than 70 years. But he had a plan, a plan to whip [CN] into shape in order to take it public, a plan to make it a respected heavyweight in North American railroading and in the whole global transportation marketplace. His plan has worked, far better than most observers thought it could, and he's convinced that the best is yet to come."

COPYRIGHT 2003 Simmons-Boardman Publishing Corporation
COPYRIGHT 2003 Gale Group

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