Transcript II_PROCARYOTIC CELL STRUCTURE

CASE STUDY INSTRUCTIONS
Note: These Case Study Materials are MSWord down loads (not Web pages) –
They should be saved onto your PC
since you will need to consult them throughout each case study.
CLICK BELOW TO JUMP TO VARIOUS CLINICAL CASE STUDY MATERIALS:
START HERE => GENERAL INSTRUCTIONS
READ THIS NEXT - A FEW ONLINE RULES OF THE COURSE
INTRODUCTION TO INFECTIOUS DISEASES - CASE STUDY STRATEGIES
RESOURCES FOR THE COMPLETION OF CLINICAL CASE STUDIES
TABLE OF NORMAL VALUES
AN EXAMPLE OF A CASE STUDY
LEVEL 1 “In the E.R.” QUESTIONS
LEVEL 3 CBC QUESTIONS
LEVEL 5 “Show-n-Tell Day” QUESTIONS
CASE CONCLUSION QUESTIONS
EXAMPLE OF A POWERPOINT CASE PRESENTATION
What is an infectious disease "Case Study?" How does it
work; what are the teaching/learning goals?
- The clinical cases were chosen
as representative of the most common bacterial infections
in developed nations
- Successfully completing the cases will require
extensive readings from the suggested texts
and integration of many concepts of microbiology
and of human biology
- At the completion these cases, the student will have
a good, basic knowledge of infectious diseases
What is an infectious disease "Case Study?" How does it
work?
- Each case is composed of:
- 5 “Levels” of sequentially disclosed information
- and a final case “Conclusion”
- At each level, the student must answer the questions
and submit the answers as an email attachment to the instructor
- The questions will address the ongoing diagnosis and clinical
evaluation of an infectious disease
- The student will need to analyze the case from the viewpoints of
both a clinical microbiologist and an infectious diseases specialist
Each case will be presented to the student in a step-wise
manner:
- ”Level 1” (the “Visit to the E.R.”) will be emailed to student by the instructor
- ”Level 2” (“Initial Lab Results”) will be emailed when the answers to Level 1
have been received by the instructor
- ”Level 3” (the “White Blood Cell Count”) will be made available at the same as
“Level 2” as a separate assignment
- ”Level 4” (“Additional Lab Results”) will be emailed when the answers to
Levels 2 and 3 have been received by the instructor
- ”Level 5” (an “Analysis of Growth on Bacteriology Media”) will be made
available at the same as Level 2 as a separate assignment
- It should not be completed until the student has received comments from the
instructor on answers from Level 1
- The ”Conclusion” will be emailed when the answers to Levels 4 and 5 have
been received by the instructor
- The student will finally prepare a summary of the each case and
of the responsible pathogen, using the standardized
“Conclusions Questions” outline attached to the case
conclusion
… Keep these questions in mind as you proceed through the case
- READ THE ”CONCLUSION QUESTIONS” NOW - KEEP A
"PAPER TRAIL!" of all your readings
- At the end of the semester, each student will present a 7- to 8minute PowerPoint presentation* of their case study to be
discussed with the class
* The presentation should be organized according to the standardized “Conclusions
Questions” outline … An example of a good PowerPoint presentation will be made
available to the student
INTRODUCTION TO INFECTIOUS DISEASES
CASE STUDY STRATAGIES
The Diagnostic Process
Congratulations upon your recent graduation from medical
school and your acceptance of an internship at Flamingham
General Hospital
As part of your training, you will be working nights and weekends
in the emergency room
And as part of the hospital administration’s efforts to downsize,
you will also be responsible for the off-hours bacteriology “stat lab”
Again, congratulations!
Your 1st Case as a Physician:
- Help! … An overwhelming amount of information to master
- An often considerable list of the “Usual Suspects”
… The most common infectious agents who might cause the
infection
- So follow the logical steps of "The Diagnostic Process"
- Each step helps to narrow down the list of causes
(including non-infectious diseases, e.g. metabolic, environmental, etc.)
The Diagnostic Process
 1st step - “Anatomical Diagnosis”
- Identification of the body site(s) that is most affected
i.e. the physical site of the “Presenting Signs and Symptoms”
- Also gather (as completely as possible) an “Oral History”
i.e. information from pertinent questions about:
- the patient’s symptoms
- past and present exposures and conditions
- the patient’s relatives
- Assign a “Syndrome” to the patient’s condition
The Diagnostic Process
 2nd step - “Differential Diagnosis”
- A "short list" of the most common diseases that present with
similar symptoms
- The list of the “Usual Suspects” - The most common infectious
agents that are associated with the signs and symptoms of the
suspected syndrome
- Note: Associations between signs/symptoms and specific
diseases are GENERALITIES:
- Not every patient will manifest the “classical” signs and
symptoms of a disease!
- Some patients may exhibit signs and symptoms of seemingly
unrelated syndromes (maybe coincidental, unrelated, and not
caused by an infectious agent)
To properly answer level 1/question #2 read the fine print (just like
with a legal contract)
- Restrict the diagnosis to bacteria, fungi, parasites, and viruses - Other practitioners will
be consulted later (and appropriately paid) to consider other causes of the illness, i.e.
the various diseases due to anatomical, physiological and genetic disorders.
- At this time, DO NOT TRY TO MAKE A “DEFINATIVE DIAGNOSIS” … It’s still too early
to be able to definitively decide which agent is infecting your patient.
- DO NOT TRY TO NARROW THE DECISION TO A SINGLE ORGANISM. Now it’s
time to think of all the possible pathogens and to begin to plan a strategy that will allow
the successful identification of the microbe that is the cause of the disease in the patient.
- This decision will help in the decision of the type(s) of sample(s) that should be
taken from the patient and upon which media those samples should be inoculated
(Questions 3 and 5.)
The Diagnostic Process
 3rd step - “Etiological Diagnosis”
- Determination of the cause of the disease
- If the disease is infectious this involves the identification of the
causative microbe
- Choose most appropriate specimen(s) to be collected from the
patient
- Decide which tests are to be performed on the specimen(s)
- At this stage, the physician will probably should have sufficient
information to reach a “Presumptive Diagnosis,” which is a best
guess about the cause of the disease, before definitive answers
are available
- At this stage, the physician will probably have sufficient
information to reach a “Presumptive Diagnosis” a best guess
about the cause of the disease, before definitive answers are
available
The Diagnostic Process
 4th step - “Epidemiological Diagnosis”
- The identification of the cause(s), distribution in the population,
and control of the disease
- Important for the present and future management of the patient,
and for others who may be at risk
- Epidemiological concepts to be considered (by the conclusion of
the case) include:
- Reservoir
- Carrier Rates
- Mode of Transmission
- Environmental or host factors that may have predisposed the
patient to the illness
The Diagnostic Process and Your Case Study
In LEVEL 1 you will begin the diagnostic process:
- Completion of the anatomical and differential diagnosis
- Beginning the etiological and epidemiological diagnosis
(which will not be completed until the end of the case study)
At this level, you will be able to make a “Presumptive Diagnosis”
(Usually there is insufficient information to reach a “Definitive Diagnosis” during the 1st
visit to the E.R.)
Do not be discouraged or overwhelmed at this level … The time
that you spend to carefully answer the questions will be rewarded
when you get the lab results and perhaps more case history at the
next levels
Next, as a Clinical Microbiologist, you will analyze the results of
the sample(s) taken from the patient to determine the causative
agent and the appropriate treatment of the disease (LEVELS 2
through 5)
Remember that the case study is completed through
SEQUENTIAL DISCLOSURE –
- The student will receive subsequent case levels only after
submission of the answers to the previous level
Finally, you must prepare for
“Friday Morning Infectious Diseases (I.D.) Grand Rounds”
(Your PowerPoint presentation to the class)
You will evaluate and summaize your initial diagnosis and the
clinical data, and prepare a review of the pathogenesis of the
causative agent and of the means of controlling or preventing the
disease(s) that it causes
A Few On Line Rules of the Course
... (These comments are based on experiences from the past)
1. When you send an email to me …
Include a meaningful description of the email’s message
in the “SUBJECT” box
Preferably the complete title of the attached case level
see below, e.g. "01_1_Earache_JANE STUDENT"
This will facilitate my prompt response to you
It’s particularly difficult to respond to a student when her/his email
address does not contain the student’s name
e.g.”[email protected]”
2. Help me out as I try to organize all the students in this class …
… 50 students … times 6 email submissions! ... equals at least 300
student files that I can potentially lose! ...
… Please follow these “NAMING RULES OF CASE LEVELS”
for the sake of your own and my bookkeeping! …
… “NAMING RULES OF CASE LEVELS” …
... Each case and case level is numbered, and then has the case
name, e.g. "01_1_Earache_your name"
DON’T CHANGE THESE!
… The file name of each case level has “your name” in it
e.g. "01_1_Earache_your name"
... As soon as you begin to work on it in MSWord, immediately do a
"Save As"
and save it as "01_1_Earache_JANE STUDENT"
That will minimize the possibility that your work will be lost or mis-filed on my computer
… When I receive your email attachment, I will "promptly" rename it
(“SaveAs”) … then correct your submission … and return them to
you
e.g. renamed as "CORR_01_1_Earache_JANE STUDENT"
... Also if you haven't yet done it, make a folder in your computer to
save everything that we e-mail to each other …
... I will do the same thing; I will have a separate folder for each
student's materials ...
... Remember to BACK-UP everything!
3. Send your case study answers as MSWord ATTACHMENTS …
… Do not directly “cut & paste” them into the text of an email …
… I cannot correct and return to you the unformatted text of an
email
4. Enter your answers
DIRECTLY INTO THE CASE LEVELS THAT I SUBMIT TO YOU
- Do not re-type them into a different format
- Do not save them using a different format
… They are MSWord documents [“.doc”] …
… Do not save them as Rich Text Format documents [“.rtf”]
... Your answers should be typed into the appropriate text boxes in
place of the "?" (Red question mark) as red text
... I will reset the "track changes" tool of MSWord and enter my
corrections as blue font
… And return it to you as "CORR_01_1_Earache_JANE STUDENT"
... Remember to BACK-UP everything!
RESOURCES FOR THE COMPLETION OF CLINICAL CASE
STUDIES
Library Resources: Selected books that will be useful for
completion of the clinical case study are often found in the
REFERENCE SECTION
FSC students are permitted to utilize the resources of the libraries
of Tufts Medical School, Wellsley College, UMASS Worchester,
and UMASS Lowell
Internet Resources:
The internet continues to offer an ever-evolving source of
excellent resources …
Personal Library Of The Instructor:
Various books and journals are on the bookshelves in the
laboratory [the “Microbiology Laboratory Library” in HH 432] These references include texts on general, medical, and food
microbiology, and on infectious diseases. The texts may NOT be
borrowed – they MUST be used in the laboratory or in the nearby
Biology Student Coference Room/Lounge [HH-401].
The “Level of Case Study” in the table [below] indicates the
location of information that will allow the student to complete the
goals of the particular steps of the case study [LEVELS 1, 2, 3].
Somewhat identical information is contained in several books [e.g.
Text # 3, 4, and 6; 2 and 5; 7 and 11], so it is not necessary to
consult each resource labeled “1” to complete LEVEL 1, etc.
Even though several of the texts are “old” [i.e. 1980], the
information that they contain is appropriately up-to-date for the
purposes of these case studies.
#
Author and Title
RELATIVE
VALUE
YOUR TEXT BOOK ... !
0
Stedman’s Medical Dictionary
1
COTRAN... - Robbins - Pathologic Basis of Disease, 1989.
3
(This and other medical dictionaries are available in the reference section of the Henry Whittemore Library)
LEVEL
of Case
Study
1,2,3
*
****
1
MANDELL,.. - The Principle and Practice of INFECTIOUS DISEASES, 1985.
**
1,2,3
4A
KONEMANN - Color Atlas and Textbook of Diagnostic Microbiology, 1980.
**
1,2,3
4B
KONEMANN - Color Atlas and Textbook of Diagnostic Microbiology, 1995.
**
1,2,3
(Newer edition available in the reference section of the Henry Whittemore Library)
(Newer edition available in the reference section of the Henry Whittemore Library)
5
JOKLIK,... ZINSSER - Microbiology, 1980.
2,3
6
DAVIS, DULBECCO,... - Microbiology, 1980.
2,3
7
RYAN, et al. - SHERRIS - Medical Microbiology, An Introduction to INFECTIOUS DISEASES, 1999.
8
MURRAY, et al. - The Manual of Clinical Microbiology 1995. [ASM]
****
1,2,3
(Newer edition available in the reference section of the Henry Whittemore Library)
**
2,3
9
MAHON, MANUSELIS - Textbook of Diagnostic Microbiology, 1995.
**
1,2,3
10
JENSEN - Microbiology for the Health Sciences, 1997.
11
BARON, et al. - Medial Microbiology, A Short Course, 1993.
[Sorry, someone stole this book, spring 1998]
(Newer edition available in the reference section of the Henry Whittemore Library)
2,3
**
2,3
Table of Normal Values
Body Temperature (T)
Heart Rate (Pulse)
Respiratory Rate
(Respiration)
Blood Pressure (BP)
pO2
37oC
60-100/min (higher for infants and
children)
9-18/min (higher for infants and
children)
90-150/50-90 (lower for infants and
children)
85-100 mm Hg
Note: mm3 = 1 L (one millionth of a liter, one thousandth of a mL)
100 mL = 1 dL (a “deciliter” is a common measure in medical literature)
Table of Normal Values
Male
Female
Hemoglobin (HGB)
Hematocrit (HCT)
13.5-18.0 g/mL
40-54%
12.0-16.0 g/mL
37-47%
Erythrocyte Sedimentation
Rate (ESR)*
Creatinine
0-20 mm/hr
0-30 mm/hr
0.8-1.5 mg/dl
0.6-1.2 mg/dl
Blood Urea Nitrogen [BUN] 8-25 mg/dL
8-25 mg/dL
Note: mm3 = 1 L (one millionth of a liter, one thousandth of a mL)
100 mL = 1 dL (a “deciliter” is a common measure in medical literature)
* ESR is usually calculated by age: male (ESR = 0.5 x age); female ESR is usually calculated by age: male (ESR = 0.5 x age); the American values given here
usually apply.
Complete Blood Count (CBC) – Normal Values
Red Blood Cells (RBCs)
Platelets
4.1-6.2 x 106/ mm3
150-400 x 103/mm3
White Blood Cell (WBCs)
4,000-10,000/mm3
"Leukocytes"
Percentage of Total WBC
Granulocytes - Polymorphonuclear
leukocytes (PMNs)
- Neutrophils
- Segmented Neutrophils
- Banded Neutrophils
47 - 77%
60 - 70%
0 - 5%
- Basophils
0 - 2%
- Eosinophils
0 - 7%
Monocytes
2 - 10%
Lymphocytes
16 - 43%
Note: mm3 = 1 L (one millionth of a L, one thousandth of a mL) ,,, 100 mL = 1 dL (a “deciliter” is a common measure in medical literature)
Cerebrospinal Fluid (CSF) - Normal Values
Obtained via Lumbar Puncture [“Spinal Tap”]
CSF Glucose
50-75 mg/100 mL
CSF Protein
15-45 mg/100 mL
CSF total nucleated
cells
0-3 WBC/mm3 (0-5 WBC/mm3)
Neonate
< 30 WBC/mm3 (various cell types)
Pediatric
< 10 WBC/mm3 (various cell types)
Adult
< 5 WBC/mm3 (lymphocytes or
monocytes, not leukocytes)
“Bloody Tap” – RBCs are not normally found in CSF. They occur if a blood vessel is hit during the procedure and circulating blood contaminates the CSF. (In blood, the ratio of RBC to WBC is 500:1
to 1000:1.)
Note: 1 mm3 = 1 L (one millionth of a liter, one thousandth of a mL)
100 mL = 1 dL (a “deciliter” is a common measure in medical literature)
Semi-Quantitative Gram Stain Interpretation of a “SMEAR”
(Number of cells seen per oil immersion field [100x magnification])
Rare
<1 cell/oil immersion field
Few
1-5 cells/oil immersion field
Moderate
>5-10 cells/oil immersion field
Many
>10 cells/oil immersion field
Negative
No organisms or cells observed after examination of
ten (10) high-power/oil immersion fields
Thanx for not falling asleep!
Dear Student,
A Few On Line Rules of the Course ... (These comments are based on experiences from the past.)
1. When you send an email to me, include a meaningful description of the email’s message in the “SUBJECT” box, preferably the
complete title of the attached case level (see below, e.g. "01_1_Earache_JANE STUDENT"). This will facilitate my prompt response to
you. It’s particularly difficult to respond to a student when her/his email address does not contain the student’s name
(e.g.”[email protected]”).
2. Help me out as I try to organize all the students in this class - 12 students … times 48 e-mail submissions! ... equals at least 576
student files that I can potentially lose! ...
… Please follow these “NAMING RULES OF CASE LEVELS” – for the sake of your own and my bookkeeping! …
... Notice how each case and case level is numbered, and then has the case name, e.g. "01_1_Earache_your name" - DON’T
CHANGE THESE!
… Also notice that the file name of each case level has “your name” in it, e.g. "01_1_Earache_your name"
... As soon as you begin to work on it in MSWord, immediately do a "Save As" and save it as "01_1_Earache_JANE STUDENT"
... That will minimize the possibility that your work will be lost or mis-filed on my computer.
… I will "promptly" correct your submissions and return them to you, again relabeled, e.g. "01_1_Earache_JANE STUDENT_CORR" ...
... Also if you haven't yet done it, make a folder in your computer to save everything that we e-mail to each other ... I will do the same
thing; I will have a separate folder for each student's materials ...
... Remember to BACK-UP everything!
3. Send your case study answers as ATTACHMENTS; do not directly “cut & paste” them into the text of an email … I cannot correct
and return to you the unformatted text of an email response.
4. Enter your answers DIRECTLY INTO THE CASE LEVELS THAT I SUBMIT TO YOU – Do not re-type them into a different format; do
not save them under a different format (they are MSWord documents [“.doc”] … do not save them as Rich Text Format documents
[“.rtf”]). As all of you work on different levels of different cases, I need to have the original questions right there to allow me to efficiently
evaluate each answer. Also, by having the question right there, it will allow you to determine if you have properly and completely
answered the questions. Some students do not really answer the question that was asked.
... Your answers should be entered into the appropriate text boxes in place of the "?" (Red question mark) as red text.
... I will reset the "track changes" tool of MSWord and enter my corrections as blue font. This will speed up both my corrections and
your review of my comments as you continue to work on each case.
5. For LEVEL 1 – QUESTION 5, you must discuss each media MANDATED WITHIN THE INOCULATION PROTOCOLS according to
your differential diagnosis and the samples that you have requested for culture!
General Instructions
For the Completion of Clinical Case Studies
OK, You're no different than 99.44% of humankind...
... You want to play with your new toy ... right now! You say to
yourself, "Why read those stinkin' instructions!" So you unpack it,
"assemble" it, plug it in, and say to yourself, "Uh ooh!" ... Then
you'll sit down, make a cup of coffee, and read the instructions,
and then say "Sure, that's it!"
But no, ... There's no reason to change your ways just now!
... So in spite of your instructor's advice, you're saying to yourself,
"Why read those stinkin' instructions!" ... So, right now, go and
click on the "Example" of a case study and try out your new
toy! Check out an example of the case studies that you will solve
as you complete this course. You'll probably then say to yourself,
"Whoa!" ... Eventually, you'll go back, and read ALL of the
instructions, and then you'll say "Sure, that's it!"
General Instructions
For the Completion of Clinical Case Studies
Editorial Note: You may actually say "Humph! Can I really
master the problem-solving skills of an infectious diseases
practitioner?"
You will be ready to test your diagnostic skills only after you read
all these course instructions and complete the suggested
introductory readings in the texts.
After that, the course instructor will provide guidance if needed particularly, as you begin your first case.
Each level of the case will present new aspects of microbial
pathogenesis that will require additional readings in the texts, and
a bit of internet surfing wouldn't hurt either! (See course's LINKS
page.) Have fun...
- In real life, this step is time-consuming and costly, and not
always necessary (e.g. it is not necessary to identify the particular
type of virus that is causing a common cold or the bacterium
causing a pediatric ear infection – in both cases the appropriate
treatment can be prescribed solely on clinical signs.)
- At this stage, the physician will probably should have sufficient
information to reach a “Presumptive Diagnosis,” which is a best
guess about the cause of the disease, before definitive answers
are available.
You will prepare a 7-to-8-minute PowerPoint presentation on
your case; it should be organized according to the standardized
“Conclusions Questions” outline.
Keep these questions in mind as you proceed through the
case - READ THE ”CONCLUSION QUESTIONS” NOW - KEEP
A "PAPER TRAIL!" of all your readings.
- For students enrolled in "Principles of Microbiology," the case
studies will be presented to the class during the lecture sessions
of the last week of the semester. You will lead a discussion of the
nuances of the case.
- For students enrolled in “Medical Microbiology” or "Theories of
Infectious Diseases," the case studies will be presented for
discussion via the internet or in class on a weekly basis.
4. Enter your answers
DIRECTLY INTO THE CASE LEVELS THAT I SUBMIT TO YOU
- Do not re-type them into a different format; do not save them
under a different format (they are MSWord documents [“.doc”] …
do not save them as Rich Text Format documents [“.rtf”]). As all of
you work on different levels of different cases, I need to have the
original questions right there to allow me to efficiently evaluate
each answer. Also, by having the question right there, it will allow
you to determine if you have properly and completely answered the
questions. Some students do not really answer the question that
was asked.
... Your answers should be entered into the appropriate text boxes
in place of the "?" (Red question mark) as red text.
... I will reset the "track changes" tool of MSWord and enter my
corrections as blue font. This will speed up both my corrections
and your review of my comments as you continue to work on each
case.
title