The Philadelphia Chromosome

The Philadelphia Chromosome

This illustration was created for JAAPA, February 2013 • 26(2).

The Philadelphia chromosome is formed when a piece of chromosome 9 exchanges places with a piece of chromosome 22, resulting in a balanced translocation t(9;22)(q34;q11) and the formation of an abnormal fusion gene BCR-ABL1.

Chronic myeloid leukemia (CML) is a myeloproliferative neoplasm. The American Cancer Society estimated that in 2012, the number of newly diagnosed CML cases would be 5,430, with 610 deaths.1 The discovery of the tyrosine kinase inhibitor (TKI) imatinib has revolutionized the treatment and prognosis of CML, making imperative early recognition of CML. Timely diagnosis will ensure that patients receive early treatment, significantly improving their prognosis.

CML is caused by a cytogenetic abnormality that is thought to be acquired and involves a balanced translocation between chromosome 9 and chromosome 22. The BCR gene on chromosome 22 fuses with the ABL1 gene on chromosome 9, resulting in the abnormal fusion gene BCR-ABL1 located on chromosome 22 (Figure 1). The fusion gene produces a protein with tyrosine kinase activity that causes cells to proliferate. The resultant abnormal chromosome 22 [t(9;22)(q34;q11)] is also known as the Philadelphia (Ph) chromosome. It is identified in 95% of patients with CML and can be detected in all myeloid cells, including granulocytes, erythrocytes, monocytes, and B lymphocytes

Craniopharyngioma

Craniopharyngioma

This illustration was produced for the Johns Hopkins University’s Suburban Hospital Magazine, New Directions, Fall 2012 issue.

A craniopharyngioma is a benign tumor that develops near the pituitary gland (a small endocrine gland at the base of the brain). This tumor most commonly affects children 5 – 10 years of age. Adults can sometimes be affected. Boys and girls are equally likely to develop this condition.
Craniopharyngioma causes symptoms in the following ways:

  1. Increasing the pressure on the brain (intracranial pressure)
  2. Disrupting the function of the pituitary gland
  3. Damaging the optic nerve

Increased pressure on the brain causes headache, nausea, vomiting (especially in the morning), and difficulty with balance. Damage to the pituitary gland causes hormone imbalances that can lead to excessive thirst, excessive urination, and stunted growth. When the optic nerve is damaged by the tumor, vision problems develop. These defects are often permanent, and may get worse after surgery to remove the tumor.

Behaviorial and learning problems may be present. Most patients have at least some vision problems and evidence of decreased hormone production at the time of diagnosis.

Traditionally, surgery has been the main treatment for craniopharyngioma. However, radiation treatment instead of surgery or along with a smaller surgery may be the best choice for some patients. In tumors that cannot be removed completely with surgery alone, radiation therapy is usually necessary. If the tumor has a classic appearance on CT scan, a biopsy may not be necessary if treatment with radiation alone is planned. Stereotactic radiosurgery is performed at some medical centers. This tumor is best treated at a center with experience in treating patients with craniopharyngiomas. [Source: A.D.A.M. Medical Encyclopedia.]

Irritable Bowel Disease

Irritable Bowel Disease

This illustration is one of the latest editorial pieces completed for the American Academy of Family Physicians featuring Irritable Bowel Disease.

Depicted are a montage of images illustrating common symptoms and treatment for IBD including stomach cramping, abdominal discomfort, the urge to use the bathroom, colon spasms and the use of antispasmodics such as hyoscyamine sulfate.

According to the featured article, “Irritable bowel syndrome (IBS) is defined as abdominal discomfort or pain associated with altered bowel habits for at least 3 days per month in the last 3 months in the absence of organic disease.  In the U.S., the prevalence of IBS is 5-10% with peak prevalence in the third and fourth decades.  Abdominal pain is the most common symptom and is often described as a cramping sensation.  The absence of abdominal pain essentially excludes IBS. Other common symptoms include diarrhea, constipation, or alternating diarrhea and constipation.  The goals of treatment are alleviation of symptoms and improvement in quality of life.  Exercise, psyllium fiber, antibiotics, antispasmodics, peppermint oil and probiotics appear to improve symptoms of IBS.  Over-the-counter laxatives and antidiarrheals may improve stool frequency but not pain.  There is conflicting evidence to support the use of antidepressants; however, psychological therapies are effective compared to usual care treatments for improvement in IBS symptoms. Lubiprostone (Amitiza™) is effective for the treatment of constipation-predominant IBS.  Alosetron (Lotronex™) and Tegaserod (Zelnorm™) are FDA-approved for patients with severe IBS symptoms who have failed conventional therapy.”

 

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