Transcript II_PROCARYOTIC CELL STRUCTURE
Note:
CASE STUDY INSTRUCTIONS
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
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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 8 minute 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 1
st
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
1 st 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
2 nd 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
3 rd 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
4 th 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 1 st 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
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 YOUR TEXT BOOK ... !
0 Stedman’s Medical Dictionary (This and other medical dictionaries are available in the reference section of the Henry Whittemore Library) 9 10 11 1 3 4A 4B 5 6 7 8 COTRAN... - Robbins - Pathologic Basis of Disease, 1989.
(Newer edition available in the reference section of the Henry Whittemore Library) MANDELL,.. - The Principle and Practice of INFECTIOUS DISEASES, 1985.
KONEMANN - Color Atlas and Textbook of Diagnostic Microbiology, 1980.
KONEMANN - Color Atlas and Textbook of Diagnostic Microbiology, 1995.
(Newer edition available in the reference section of the Henry Whittemore Library) JOKLIK,... ZINSSER - Microbiology, 1980.
DAVIS, DULBECCO,... - Microbiology, 1980.
RYAN, et al. - SHERRIS - Medical Microbiology, An Introduction to INFECTIOUS DISEASES, 1999.
(Newer edition available in the reference section of the Henry Whittemore Library) MURRAY, et al. - The Manual of Clinical Microbiology 1995. [ASM] (Newer edition available in the reference section of the Henry Whittemore Library) MAHON, MANUSELIS - Textbook of Diagnostic Microbiology, 1995.
JENSEN - Microbiology for the Health Sciences, 1997.
BARON, et al. - Medial Microbiology, A Short Course, 1993.
[Sorry, someone stole this book, spring 1998] RELATIVE VALUE
LEVEL of Case Study 1,2,3
* **** ** ** ** **** ** ** **
1 1,2,3 1,2,3 1,2,3 2,3 2,3 1,2,3 2,3 1,2,3 2,3 2,3
Table of Normal Values
Body Temperature (T) Heart Rate (Pulse) Respiratory Rate (Respiration) Blood Pressure (BP) pO 2 37 o C 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: mm 3 = 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) 13.5-18.0 g/mL Hematocrit (HCT) Erythrocyte Sedimentation Rate (ESR)* 40-54% 0-20 mm/hr Creatinine 0.8-1.5 mg/dl Blood Urea Nitrogen [BUN] 8-25 mg/dL 12.0-16.0 g/mL 37-47% 0-30 mm/hr 0.6-1.2 mg/dl 8-25 mg/dL Note: mm 3 = 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 10 6 / mm 3 150-400 x 10 3 /mm 3
White Blood Cell (WBCs)
"Leukocytes"
Granulocytes
- Polymorphonuclear leukocytes (PMNs) -
Neutrophils
- Segmented Neutrophils - Banded Neutrophils -
Basophils
-
Eosinophils Monocytes Lymphocytes
4,000-10,000/mm
47 - 77% 60 - 70% 0 - 5% 0 - 2% 0 - 7% 2 - 10% 16 - 43% Note: mm 3 = 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)
3
Percentage of Total WBC
Cerebrospinal Fluid (CSF) - Normal Values
Obtained via Lumbar Puncture [“Spinal Tap”]
CSF Glucose CSF Protein CSF total nucleated cells 50-75 mg/100 mL 15-45 mg/100 mL 0-3 WBC/mm 3 (0-5 WBC/mm 3 ) Neonate Pediatric Adult < 30 WBC/mm 3 (various cell types) < 10 WBC/mm 3 (various cell types) < 5 WBC/mm 3 (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 mm 3 = 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 Many >5-10 cells/oil immersion field >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" CHANGE THESE!
… Also notice that the file name of each case level has “your name” in it, e.g. "01_1_Earache_your name" DON’T ... 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.