22
August
2007
Vitamin D deficiency is more prevalent than ever, probably because we don’t get enough sunlight. But with Mr. Ozone disappearing like characters on Lost, we are intentionally avoiding the sun to prevent skin cancer. Vitamin D isn’t really in a lot of foods, so ultraviolet B radiation is/was a major way to convert 7-dehydrocholesterol to previtamin D3 (it takes a series of step for the body to make active vitamin D which is called 1,25-dihydroxyvitamin D). It is estimated 1 billion people have either vitamin D deficiency or insufficiency, in particular those who live in northern climates. More than half women who are past menopause, osteoporotic, and on meds for bones are vitamin D deficient. Nearly half kids and younger adults have vitamin D deficiency by the end of winter.
Vitamin D is necessary for healthy bones, and it seems for many other organs. The body absorbs calcium and phosphorus in the gut much better with assistance of vitamin D. Also if vitamin D gets low, parathyroid hormone rises and that can thin out the bones.
25-hydroxy vitamin D is what is measured to see a person’s vitamin D level. 20-100 is considered normal though most studies in the NEJM 2007;357:266-81 article lean towards 40-100. <20 is deficiency and 20-39 seems insufficiency. Greater than 100 and definitely more than 150 is vitamin D toxicity
Foods that have vitamin Vitamin D – eh, not very many. Fresh wild salmon 3.5oz has 600-1000IU of vitamin D which is a healthy daily dose for most. Farmed raised salmon only has 100-250IU. Cod liver oil 1tsp has 400-1000IU – just like what I saw on The Waltons when the nurse practitioner tried to prevent rickets in the children. 1 serving of fortified milk, fortified OJ, infant formulas, fortified yogurt (8oz, not 6), fortified cheeses (3oz), and fortified breakfast cereals have 100IU of vitamin D.
But for those who don’t get enough sun exposure, it appears 800IU of vitamin D is what is needed to keep levels in good range. So over the counter vitamin D might be required. Rx vitamin D is also available for those in particular with osteoporosis or osteomalacia.
Osteomalacia means the quality of the bone is not healthy and that can cause bone pain. So there is an observation of people with bone pain who feel better once repleted with vitamin D.
Brain, prostate, breast, colon and muscles have vitamin D receptors. So there is also an observation of decreased muscle pain and less falling down with replacement of vitamin D in those who were deficient or insufficient. Also the immune system appears to work poorly if there is vitamin D and even a correlation of Type I diabetes with vitamin D deficiency. Tuberculosis appears to be more prevalent in those who are vitamin D deficient, such as in African Americans in northern climates. Arthritis appears to be improved with vitamin D levels in good standing. The NEJM also talks about other disorders that are associated with vitamin D but they appears to be weak links such has depression, schizophrenia, hypertension, heart disease, multiple sclerosis, and cancer.
Besides lack of sun exposure, there are some genetic causes or illnesses that can lead to vitamin D deficiency. Medicines that can destroy vitamin D include HIV medications, anticonvulsants, and glucocorticoids. Other things that can lead to vitamin D deficiency include: well, sunscreen, darker skin due to melanin, winter time, kidney disease, liver disease, and malabsorption syndromes
drjohnhong 
Uncategorized, food, Bones & Muscles, Endocrinology 
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15
August
2007
Acute Pharyngitis is the medical term for new onset of sore throat. Only 10% of patients who see the doctor for a sore throat have Group A Streptococcus (GAS) – which is #1 treatable bacterial infection. Other strept infections are Group C and Group G. STD bugs N. gonorrhoeae and Chlamydia can cause sore throats. Mycoplasma (which causes walking pneumonia) is an atypical bacteria. So these bacteria just named consist of only 15-30% cases seen by doctors that will respond to antibiotics. C. diphtheriae is pretty rare because tetanus-diphtheriae vaccines. The rest of infections don’t respond to antibiotics – in particular viruses, which consist of 50% of cases of sore throats in a doctor’s office.
Pharyngitis caused by a virus will not be cured with antibiotics. Virus include Epstein-Barr virus (mononucleosis) and HIV acute infection. Other viruses include rhinovirus (common cold), adenovirus, parainfluenza, coxsackievirus (hand, foot and mouth disease), coronavirus, echovirus, CMV (mono as well), and herpes simplex. Influenza can be treated with Tamiflu.
30% cases a pathogen is not found on throat culture.
Clinical: Sore throat comes on pretty quickly. Tonsils are swollen with exudate (pus or discharge) + Lymph nodes in neck + Fever make the triad for strept throat + lack of cough. If there are other symptoms like stuffy runny nose, sneezing, ear congestion, and coughing then it is likely a virus infection and not strept.
But still studies show doctors often don’t know which patients will have a positive throat culture for GAS if they have the classic signs of strept throat. On the other hand, if 3/4 signs are negative for strept, then about 80% of the time the patient doesn’t have strept throat.
So the rapid strept test is used because the strept culture takes 24-48 hours. But the rapid strept test isn’t perfect: only 80% sensitive. A blood test called ASO can aide in diagnosis but that takes a day as well.
GAS needs to be treated with antibiotics to help prevent acute rheumatic fever, which can cause heart valve damage and kidney damage. Also early treatment with antibiotics can help prevent an abscess forming.
Worst case scenarios for sore throat include an abscess, swollen epiglottis, or parapharyngeal space infections. It might be a bad sign to have drooling, dysphagia (difficulty swallowing) and neck swelling and might require emergency treatment
Symptoms can be reduced with common things like: warm salt water gargles, Listerine, herbal teat with licorice root. NSAIDs like Tylenol (if no liver problems) and ibuprofen (risk of higher blood pressure and stomach ulcers)
drjohnhong Uncategorized, infection Comments (0) » |
8
August
2007
Benign Positional Vertigo (BPV) is vertigo that occurs with head positional changes. Vertigo means a spinning sensation, not lightheadedness. The in peripheral BPV, the ear contains the balance center, and it senses gravity and crystals in the balance center causes the spinning sensation. In central BPV, vertigo occurs because of a problem in either the brain’s brainstem or cerebellum. Unlike central BPV in which the vertigo stays as long as the head is in the “right” position, peripheral BPV is transient – so it “burns” out after a while despite being in the same head position.
Clinical: vertigo spells usually less than a minute. BPV affects a person weeks to months without meds or intervention. Then poof! It goes away on its own. It can come back periodically and for some reason vertigo occurs mostly in the spring time.
What triggers a spell: rolling in bed, getting out of bed, looking over the shoulder, looking up.
Nausea and even vomiting can occur because dizziness can make you up-chuck.
Cause: in peripheral BPV the balance center of the inner ears (semicircular canals) have foreign bodies (like calcium crystals). These crystals hit the triggers in the canals and it gives the sense of spinning, like on a roller coaster or merry go round. The calcium crystals come from the utricular sac (where all 3 semicircular canals meet)
35% of the time there is no known reason for BPV. Some causes are head trauma, Meniere’s disease (30% of cases), history of ear surgery, vestibular neuritis, stroke to inner ear, and giant cell arteritis.
For those who have central BPV (the vertigo doesn’t diminish as long as the head stays in that position), MRI probably needs to be done to check for Chiari malformation, cerebellar degeneration, and spinocerebellar ataxia.
Diagnosis: Dix-Hallpike and Barany Maneuvers are easily done in the doctor’s office, unless you have a neck problem like Rheumatoid arthritis. Both maneuvers swing the head around to invoke vertigo. Vertigo is seen by the doctor by something called nystagmus – the eyeball swings around or back and forth very quickly.
Treatment: ENTs are known to reposition the head to get the calcium crystals out if it is peripheral BPV: Epley maneuver. Brandt-Daroff exercises as well.
Medicines are to treat the dizzy feeling and if necessary nausea and vomiting.
For those who have recurrent BPV, it comes on usually 1-3x/year but for most people BPV doesn’t haunt them for life.
Hearing test might be needed to check for Meniere’s Disease.
drjohnhong Uncategorized, neurological Comments (0) » |
2
August
2007
Pancreatic cancer is the #4 killing cancer in USA. About 33,000 cases occur a year and about 32,000 deaths a year from pancreatic cancer. It is deadly because it isn’t diagnosed until too late. Only 15% of those diagnosed with pancreatic cancer are considered for surgery, but even then their 5 year survival rate is only 25% (if no spread to lymph nodes) and 10% for those with spread to lymph nodes.
Risk factors: Usually occurs after the age of 45. Greater in men and in African Americans. Smoking, diabetes mellitus, chronic pancreatitis, and genetics. 10% persons with pancreatic cancer have family history of it.
Clinical: Weight Loss, Abdominal Pain (from navel region radiating straight to the back), and jaundice. The belly pain is often worse with eating and is a dull ache. Fatty stools (floaters and light colored stools) and diarrhea due to pancreatic insufficiency, anorexia, and early satiety (feeling filled up after on a few bites). Bloating and belching can be early symptoms. Virchow’s node is a left supraclavicular lymph node. Symptoms probably start 3 years before diagnosis is made.
Diagnosis: abdominal ultrasound is 80% sensitive in picking up pancreatic cancer. CT, MRI are 90% sensity. ERCP (endoscopy all the way into the duodenum) is 90% sensitive. A fine needle aspirate is 90% sensitive (guided by ultrasound or CT). Though not proven doing the needle aspirate can spread the tumor by “leaking” cancer cells out, it isn’t usually done in a patient who is going to have surgical resection.
For staging the spread of the cancer, Helical CT and IV contrast (for CT angiography) can see if the cancer has spread into the major arteries and veins. Hopefully it hasn’t. But it isn’t sensitive enough to pick up metastasis to the liver if the cancers there are small. MRCP is better at detecting spread of cancer into the liver.
Endoscopic ultrasound is 90% sensitive in detecting pancreatic cancer and can be useful in staging.
CA 19-9 is a blood test to check on the pancreatic tumor marker. It is about 80% sensitive so isn’t good as a screen for early pancreatic cancer. The bigger the tumor, the higher the CA 19-9. So high level such as more than 1000 usually indicates surgery isn’t going to be helpful.
Treatment: Surgery with adjuvant chemotheraphy might be helping people survive longer – in those who were candidates for surgery. For those with inoperatable cancer, palliative treatment (meaning minimize the pain and problems) is suggested.
Prevention: for those at higher risk for pancreatic cancer, it has not been shown yet if checking tumor marker CA 19-9 is useful and having CT scan or ultrasound will work. Also your insurance, if you have it, probably won’t cover it.
drjohnhong Uncategorized, cancer Comments (0) » |
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