Markdown bug??

[Joshua E Cook]

Hi,

I'm trying to use Markdown in document production and I'm running into 
a problem with a certain block of text.  After parsing the text below, 
the section "Complications of Chronic Pancreatitis," along with some 
following sections are not output correctly.  Instead what appears to 
be an md5 hash is output.  What's strange is that if I remove the first 
("Structural Damage") or last ("Pain Management") sections, the output 
then seems to be correct.  The excerpt below is part of a larger 
document, but I think that I have isolated this behaviour to something 
within this excerpt.  I'm not sure if this is a bug in Markdown, or if 
it is some problem with my text, but any help you can give me would be 
much appreciated.

Thanks,
Joshua E Cook

What follows is the text excerpt that I'm using for input (this text is 
copyrighted):

#### Structural Damage

* Imaging Studies

     * _Computed Tomography (CT) scan of the abdomen._  A CT scan may 
reveal dilation of the pancreatic duct containing stones, fluid 
collection or pseudocysts, and/or calcification of the pancreas as well 
as focal enlargement and tissue atrophy.  A CT scan may demonstrate one 
or more of these changes in 80% - 95% of patients with chronic 
pancreatitis.  CT is most accurate in imaging moderate to severe 
chronic pancreatitis.

     * _Plain X-ray of the abdomen._   An  X-ray of the abdomen might 
show multiple areas of calcification in the pancreas.  This is the 
simplest and the least expensive test used to diagnose chronic 
pancreatitis.  Unfortunately, this test is positive only in 40% of 
patients.

     * _Abdominal ultrasound (sonogram)._  Images of the pancreas 
obtained by abdominal ultrasound may show similar changes as a CT scan. 
  The sonogram may show tissue irregularity, stones, or certain types of 
structural change.

     * _Endoscopic retrograde cholangiopancreatography (ERCP)_ is the 
"gold standard" for diagnosing chronic pancreatitis.  The sensitivity 
of ERCP for diagnosis of CP is 75-95%.  This test is done under 
sedation while the patient is lying on the X-ray table.  An endoscope 
or lighted tube is passed into the upper part of the small intestine, 
near the opening of the pancreatic duct.  Contrast material is then 
injected into the pancreatic duct, enabling the physician to visualize 
the ductal changes under X-ray guidance.  Changes in the duct such as 
widening or narrowing, presence of stones, etc. can be identified 
during ERCP.   ERCP is also a valuable tool in imaging early signs of 
tissue damage as it enables the doctor to take a sample of pancreatic 
tissue for biopsy.

         One of the complications of ERCP is that it can irritate the 
pancreatic tissue and lead to post-ERCP pancreatitis.  The main 
drawback of ERCP is that it is an invasive test, requires sedation, and 
is associated with complications (up to 40% of patients, by some 
estimates).

     * _Magnetic resonance cholangiopancreatography (MRCP)_ provides 
images of the abdominal viscera, including the liver, biliary tree, and 
pancreas. The pancreatic tissue is clearly seen, pancreatic duct is 
highly visible, and pockets of pancreatic fluid can be visualized.  
Unlike ERCP, MRCP is not invasive and does not require sedation and so 
is becoming an increasingly useful tool in the diagnosis of CP.  The 
drawback of MRCP is that for early chronic pancreatitis, it does not 
image subtle changes with the clarity of ERCP.

         Because MRCP is a relatively recent tool used in the diagnosis 
of CP,  there is considerable variability of accuracy between imaging 
centers due to different types of scanners as well as lack of 
uniformity among operator skills.

     * _Endoscopic Ultrasound (EUS)_ uses a specialized endoscope, which 
houses an ultrasound source.  This specialized scope is passed into the 
stomach and upper small intestine.  Ultrasound images of the pancreas 
as well as the pancreatic duct are obtained and calcifications can be 
seen.  Calcifications can be indicative of complications of chronic 
pancreatitis.   Recent reports indicate that endoscopic ultrasound may 
be more useful for detecting early changes of chronic pancreatitis.  If 
needed, an aspiration needle can be passed through the endoscope into 
the pancreas to obtain tissue samples for analysis.

     Imaging the pancreas also enables doctors to track complications 
such as calcium deposits.  At later stages of chronic pancreatitis, 
doctors can monitor the severity of progression with various scans.


### Complications of Chronic Pancreatitis

* _Pseudocyst._  This is a fluid collection contained within a 
well-defined capsule.  Pseudocysts may develop with acute or chronic 
pancreatitis.  If the pseudocyst is not symptomatic, it may resolve 
spontaneously.  However, if it is symptomatic and is connected to the 
pancreatic ductal system, it usually will not resolve without surgical 
intervention (e.g., drainage).

* _Calcifications._  These are small deposits of mineral salts that 
collect in the pancreas and lead to destruction and hardening of the 
tissue.  Calcifications can develop up to 8-10 years after the first 
attack of pancreatitis and if necessary are removed surgically.

* _Pancreatic duct dilitation or stricture._

* _Obstruction of bile ducts._  If the pancreatic tissue becomes hard 
and fibrous, it can lead to stenosis or obstruction of the biliary 
ducts.

* _Duodenal stenosis._  Narrowing of the duodenum.

* _Portal hypertension._  Increased pressure in the biliary ducts which 
originate in the liver.

* _Ascites._  Ascites are a collection of fluid in the peritoneal 
cavity which can occur if a cyst ruptures.

* _Blood clots in the splenic vein._  This is a very rare complication.

* _Diabetes._  This develops in approximately one third of patients 
with chronic pancreatitis.


### Risk for Pancreatic Cancer

Chronic pancreatitis in general, and hereditary pancreatitis in 
particular, are considered risk factors for pancreatic cancer.  
Presently, the incidence of cancer occurs in approximately 5% of 
patients but scientists expect that as the genetics of pancreatitis and 
pancreatic cancer is better understood, recognition of the relationship 
between these two pancreatic conditions will account for a higher 
percentage.

There is a pancreatic lesion classification system which has been 
proposed, called PanIN (pancreatic intraepithelial neoplasia) which 
describes three stages of lesions in the pancreas that are considered 
to be precursors for cancer.  All of these stages have been found in 
chronic pancreatitis.

Doctors consider it important for patient with chronic pancreatitis to 
undergo endoscopic ultrasound once a year with aspiration or biopsy of 
any mass in the pancreatic duct wall.  Patients with positive outcomes 
should consider prophylactic surgical resection in order to try and 
avoid what may be an increased probability of developing cancer.


### Classification of Chronic Pancreatitis

Presently there are no universally accepted classification systems to 
help in the diagnosis  of chronic pancreatitis.  The Cambridge 
Classification System of 1984 uses imaging to determine grade and 
severity but it does not distinguish between different causes of 
chronic pancreatitis and their manifestations.  This system is more 
frequently used for staging chronic pancreatitis (mild, moderate, and 
severe) once the diagnosis has been made.

There is a new classification system, called the TIGAR-O (an acronym 
for the causes of chronic pancreatitis - Toxic-metabolic, Idiopathic, 
Genetic, Autoimmune, Recurrent and severe acute pancreatitis, 
Obstructive).  This system classifies chronic pancreatitis according to 
etiology and categorizes each patient based on factors most associated 
with their specific case.   However, this system is not widely used and 
research continues in the field of classification and progression of 
chronic pancreatitis.


### Treatment Options

#### Standard of Care

The goals of therapy for chronic pancreatitis are pain management, 
restoration of pancreatic function, and the detection and management of 
complications.  Treatment plans usually consist of some or all of the 
following elements:

* Pain relief with medication, endoscopy,  surgery, or nerve block
* Restoration of pancreatic function and nutritional status:
     * Supplementary pancreatic enzymes
     * Low fat diet/high carbohydrate diet
     * Supplements of vitamins and/or calcium, as needed
* Control of blood sugar if diabetes has developed
* Management of complications
* Total abstinence from alcohol and tobacco

The treatment of chronic pancreatitis depends on several factors such 
as the cause of the pancreatitis, the extent and location of damage of 
the pancreas, the presence or absence of symptoms, complications, and 
the general health of the patient.  When symptoms are mild or absent 
("silent pancreatitis") no treatment is indicated.


#### Pain Management

* _Medications_

     Pain is usually the most prominent symptom in chronic pancreatitis 
and is very difficult to control in many patients.  Due to the severity 
of pain which can be episodic or chronic and intractable, most patients 
with chronic pancreatitis require some kind of pain medication. For 
milder pain, milder analgesic medication such as Tylenol may be all 
that is necessary.  However, if the pain is severe, narcotics and even 
tranquilizers may be needed.  Some pain medications can be administered 
through skin patches (e.g. fentanyl) which provide a slow, steady 
release of the drug into the blood.  Dependence on narcotics is an 
issue for many patients with chronic pancreatitis.

* _Endoscopic treatment_

     When pain control is not achieved with medical treatment, patients 
may consider endoscopic surgery.  The goal of endoscopy is to enhance 
the flow of pancreatic juice through endoscopic procedures that may:

     * Enlarge the pancreatic or bile duct opening
     * Remove stones from the pancreatic or bile duct
     * Place tubes or stents in the pancreatic duct to open ductal 
strictures
     * Drain pseudocysts

     The success rate for endoscopic procedures is between 60-80% by 
some estimates.  Although there is some controversy as to the long term 
efficacy of endoscopic treatment, a major advantage is that it is not 
as invasive as open surgery, there is a shorter recovery period, and it 
is associated with fewer complications.

* _Surgery_

     Surgery is performed when more conservative therapies have been 
exhausted.  Sometimes, the patient is also in a situation where there 
may be a risk of addiction to pain medication.  The objective of 
surgery is to resect (remove) as little tissue as possible in order to 
achieve improvement of symptoms, particularly disabling pain or 
flare-ups of pancreatitis.

     Approximately 50% of patients with chronic pancreatitis undergo 
surgery at some point to either treat complications or to manage pain.  
Surgery does not stop exocrine or endocrine loss of function.  Results 
of surgery indicate that 60-70% of patients find relief from surgery 
but after 5 years, the benefits begin to diminish over time.

     Surgical procedures are determined by the symptoms and their 
severity, in combination with the location and extent of damage to the 
pancreas.  Since pain is believed to be related to increased pressure 
or tension in the pancreatic duct, creating an additional outlet for 
enhancing the pancreatic flow, and thereby decreasing the tension, is 
an important part of most surgeries.

     There are two types of surgical procedures that are considered for 
chronic pancreatitis:

     * Pancreatic resection
     * Pancreatic removal with islet cell transplantation

* _Pancreatic Resection_

     Pancreatic resection is performed with some of the following goals 
in mind:

     * Pain relief
     * Pancreatic drainage
     * Maximizing whatever pancreatic function that can be salvaged

     Pancreatic resection comprises several different types of 
procedures.  Included among them are:

     * _Puestow procedure._  This is also called a _lateral 
pancreaticojejunostomy_ in which the pancreatic duct is connected to 
the small intestines so that pancreatic juices drain directly into the 
intestines.

     * _Frey procedure._  The Puestow procedure is combined with 
removing part of the pancreatic head to improve pancreatic duct 
drainage.  This procedure may be performed if there is damage to the 
pancreatic head or if there is enlargement of the pancreatic head.

     * _Beger procedure._  Most of the pancreatic head is removed while 
sparing the duodenum, stomach and bile duct.  This procedure may be 
performed to treat an enlarged pancreatic head.  This procedure is more 
commonly done in Europe but is gaining favor in the US.

     * _Whipple procedure_ (Pancreatoduodenectomy).  Classic 
pancreaticoduodenectomy  in which the head of the pancreas along with 
the small bowel embracing the head, the gall bladder and part of the 
bile duct and stomach are removed enblock. The remaining part of the 
pancreas is connected to the small intestine. The modified 
Pylorus-Preserving Pancreaticoduodenectomy preserves the entire 
stomach, the pyloric sphincter, and maintains more normal gastric acid 
secretion and hormone release, thus minimizing nutritional 
complications. Since pylorus preservation does not seem to be 
associated with any consistent additional complications, pylorus 
preservation is favored in most patients who undergo 
pancreaticoduodenectomy.

     * _Pylorus preserving Whipple procedure_ has been the "gold 
standard" for chronic pancreatitis surgery but newer techniques 
continue to develop which may be as effective in regard to pain relief 
and optimization of remaining exocrine and endocrine function.

     * _Distal Pancreatectomy._  This procedure involves removal of the 
body and tail of the pancreas.  Because of the proximity of the tail to 
the spleen, damage in the tail may be associated with splenic 
complication.

* _Total Pancreatectomy and Islet Cell Transplantation_

     Total pancreatectomy involves removal of the entire pancreas and 
may offer permanent symptom relief.  Since it is a more radical surgery 
and may involve significant complications, it is considered as an 
option only when all other efforts have failed.

     When the pancreas is removed, the patient may develop diabetes 
mellitus due to the loss of pancreatic islet cells which produce 
insulin.  In order to prevent this complication, the available 
insulin-producing cells from the patient's pancreatic islet can be 
transplanted into the liver during the same operation.

     In five-year follow up studies, surgery appears to be superior to 
endoscopy for long term pain reduction in patients with chronic 
pancreatitis.  There are indications that partial or local resection of 
the pancreatic head yield significant pain relief for most patients.

* _Celiac Plexus Neurolysis (Nerve Block)_

     As a last resort, nerve block, or paralyzing the pain conducting 
nerve center (celiac ganglion), may be performed.  This is usually 
achieved by injecting alcohol directly into the celiac ganglion under 
X-ray or ultrasound guidance.  This technique has not proven itself 
effective especially for young patients who have undergone surgery.

     Celiac block performed with the help of endoscopic ultrasound is a 
more recent advancement.  Doctors achieve nerve block with the use of 
steroids and/or local anesthetics which are safer than alcohol.  This 
procedure continues to undergo development.

     The nerve fibers can be disconnected or cut during an operation, a 
procedure referred to as _Splanchenectomy_ or _Splanchenic nerve 
block_.

* _Other_

     There are patients in whom the pain is intractable and who 
experience minimal relief despite varying treatment plans.  For these 
patients their quality of life does not improve despite all of the 
efforts.  These patients may be referred to pain clinics in various 
medical centers where the patient is taught how to cope with pain.  
They also may be given different types of medication which are 
non-narcotic that are not traditionally used for pain but may be 
effective.  Many pain centers offer auxiliary services such as 
counseling in order to help the patient and their family cope with the 
very difficult situation.