Professor
Brian Andrews NEJM Recommendations for Medical Students and Tutors
Week
of 10th March 2016 (#33)
University
of Notre Dame Australia (Fremantle Campus)
Occasional Editorial Comment
None
Must Read Articles
REVIEW ARTICLE
Mesenteric
Ischemia
Although
mesenteric ischemia is uncommon, it can be life-threatening, and its
recognition is therefore crucial. This review article explains the
pathophysiology, diagnosis, and treatment of intestinal ischemic
syndromes.
Like the review article in the previous issue of the Journal on Peripheral Artery Disease,
this review on mesenteric ischaemia is an extensive, but easy read. It should
be read by all those with a particular interest in the area, by those managing
a patient with mesenteric ischaemia, or when specific details on investigation
and treatment are needed.
Recommended
learning: Pathophysiology, presentation and general management
of acute and chronic mesenteric ischaemia.
VIDEO and TEXT
Lymph-Node
Palpation — No Laughing Matter
Examination
of ticklish patients can be difficult. An approach to overcoming a patient's
resistance to palpation is suggested.
This is an interesting video which demonstrates a
technique to examine lymph nodes in a ticklish patient. The physiological basis
of the technique is also discussed.
Recommended
learning: Review the major lymph node groups which are routinely
examined, their associated drainage areas and the methods of clinical
examination.
Articles Recommended for Medical Students
ORIGINAL ARTICLE
Survival
Benefit with Kidney Transplants from HLA-Incompatible Live Donors
This
multicentre trial showed that, despite immunologic challenges, recipients of
kidney transplants from HLA-incompatible live donors had a survival benefit as
compared with controls who remained on the waiting list or received transplants
from deceased donors
EDITORIAL
HLA-Incompatible
Kidney Transplantation — Worth the Risk?
This landmark article, together with the Editorial, should be read by all medical
students.
Currently the number of patients with ESRD worldwide on
chronic haemodialysis continues to markedly outnumber the number of live (few)
and cadaveric HLA-compatible donors available to a recipient population that
continues to increasing in age and exhibit a high frequency of diabetes
mellitus.
Earlier studies from the renal transplant unit at the
Johns Hopkins University School of Medicine (single centre) demonstrated a
significant survival benefit in recipients of renal transplants performed using
live kidneys from HLA-incompatible donors. The international transplant community and
health care systems have been reluctant to embrace this finding.
This study from 22 transplant centres within the US
over a 14-year period now analyses the survival benefits for 1025 patients with
ESRD who received live transplants from HLA-incompatible donors, of whom 5.8%
were also ABO-incompatible. All recipients received perioperative
desensitization therapy (discussed in the Methods section and the Editorial) for donor-specific antibodies
detected prior to transplantation. The control groups were: i) the waiting-list-or-transplant control
group (for patients on dialysis of whom 45.4% received cadaveric transplants
over the 8-year study, n=5152) and, ii) the waiting-list only control group who
received dialysis only over the 8-year period (n=5152). Survival rates were
analysed at fixed time periods throughout the study. At every time period, the
live donor group had the best survival rates. At the 8-year period, the
survival rates for the three respective groups were 76.5%, 62.9%, and 43.9%,
indicating a twofold survival difference between those receiving live
HLA-incompatible kidneys and those remaining on haemodialysis. Even in the
group with a positive cytotoxic cross-match, a similar survival pattern
existed. When data from the most experienced Johns Hopkins group were excluded
from the analysis, similar results were obtained.
This study will be actively discussed and I predict new
transplant policies will be formulated.
Recommended
learning:
1. Review
the indications for transplantation of specific organs.
2. Review
complications of specific transplanted organs.
3. Review
types of graft rejection and their immunopathological basis
4. Review
the infectious complications of immunosuppression associated with
transplantation (Don’t forget the most common infections are warts and fungal
nail infections which are a major problem for the patient but not necessarily
the doctor).
ORIGINAL ARTICLE
BRIEF REPORT
Zika
Virus Associated with Microcephaly
Zika
virus is an emerging infectious disease that is spreading rapidly through the
Americas. A major concern is the association with birth defects, especially
microcephaly. This report shows evidence of Zika virus in the fetal brain.
EDITORIAL
Zika
Virus and Microcephaly
As the knowledge of Zika virus infection continues to
evolve rapidly, what is current one day may be out of date the next.
In this Brief
Report, an autopsy on an aborted fetus, with ultrasonographic evidence of
microcephaly with microcalcification of the brain and placenta, from a patient
with Zika virus (ZIKV) infection from Brazil is described.
Extensive macroscopic and microscopic examination of
the brain and spinal cord was performed, including immunohistochemical and
immunofluorescent demonstration of the ZIKV within neural tissue. The complete
genome of the ZIKV was recovered from the fetal brain and is similar to the
strain that has emerged from the Asian lineage. Two major amino acid
substitutions positioned in non-structural proteins NS1 and NS4B may represent
an accidental event or indicate a process of eventual adaptation of the virus
to a new environment.
CASE RECORDS OF THE MASSACHUSETTS GENERAL HOSPITAL
Case
7-2016 — An 80-Year-Old Man with Weight Loss, Abdominal Pain, Diarrhea, and an
Ileocecal Mass
An
80-year-old man presented with anorexia, weight loss, abdominal pain, diarrhea,
and an ileocecal mass.
This is an interesting case but I wonder why it took so
long to diagnose tuberculosis in this patient, an immigrant from South-East
Asia, who was immunosuppressed as a result of CKD but who still exhibited 8 mm
of induration on a tuberculin skin test and a positive g-interferon release assay for M. tuberculosis. It should also be noted that the ileocecal mass
was a CT positive mass and was not palpable but visualised on colonoscopy.
I also wonder when the NEJM will present the white cell
differential counts as absolute values rather than a percentage?
IMAGES IN CLINICAL MEDICINE
Midline
Destructive Lesions in a Cocaine User
A 44-year-old man with a history of
cocaine use presented with a 1-year history of headache and progressive frontal
syndrome. Examination revealed ophthalmoparesis due to mechanical restriction
of eye movements, mild pyramidal syndrome, and a defect in the palate.
The authors discuss the difficulty in differentiating
between angiitis with granulomatosis (formerly Wegener’s granulomatosis) and cocaine use in this clinical
situation, particularly where vasculitis is not demonstrated in the upper
airway pathology and where cocaine use is vehemently denied by the patient. ANCA
positivity in angiitis with granulomatosis is usually directed against the
serine proteinase, proteinase-3, while the ANCA positivity with cocaine use is
usually directed against human neutrophil elastase.
IMAGES IN CLINICAL MEDICINE
Tinea
Versicolor
A
24-year-old woman presented with a 12-year history of a depigmenting rash. She
reported prominent scaling, particularly after showering. Over the preceding 2
to 3 years, the rash had spread to include her entire torso, with extension
down her arms.
It is a pity that it took 12 years to diagnose and
treat tinea versicolor in this patient.
Recommended
learning: Classical presentation and management of tinea
versicolor. Review clinical pictures in the Australian College of Dermatology
slide collection (MED300 only), in the New Zealand College of Dermatology
clinical slide collection web page, or at dermis.com.
Important Articles Related to Mechanisms of Disease and
Translational Research
None
Other articles which should be of interest to medical students
Perspective
On
the Road (to a Cure?) — Stem-Cell Tourism and Lessons for Gene Editing
Many
desperate patients have left the United States seeking unproven and risky
stem-cell interventions available in countries with less rigorous regulation.
How can we keep gene editing from triggering a new wave of medical tourism?
Perspective
Disheartening
Disparities
A
year after losing his father to hypertrophic cardiomyopathy, a young man from
Zimbabwe begins medical school in New York. When screening reveals that he has
the same condition, he receives cardiac care that could not differ more from
his father's.
EDITORIAL
Treatment
of Malaria in Pregnancy
This Editorial provides an overview of P. falciparum malaria
during pregnancy and the results of two studies in the current Journal (http://www.nejm.org/doi/full/10.1056/NEJMoa1508606 ;
http://www.nejm.org/doi/full/10.1056/NEJMoa1509150
). Unless you have a particular interest in this area, all you need to read is
the Editorial.
Malaria in pregnancy is a major worldwide public health
problem, resulting in increased risk of spontaneous abortion, still birth, or
low birth weight. Various treatment protocols are reviewed for both the
treatment of malaria and for the prevention of malaria in the pregnant patient
in sub-Saharan Africa, but all treatments utilizing
artemisinin/dihydroartemisinin as the major component of the protocol. This
drug is the mainstay of treatment of chloroquine-resistant P. falciparum malaria, which represents the majority.
Artemisinin is isolated from the plant Artemisia
annua, sweet wormwood, an herb employed in Chinese
traditional medicine. A prodrug can be genetically engineered
in yeast (Wikipedia).
MEDICINE AND SOCIETY
N-of-1
Policymaking — Tragedy, Trade-offs, and the Demise of Morcellation
Anecdotes like those about women who receive a
diagnosis of late-stage leiomyosarcoma after morcellation of fibroids can skew
risk perception, leading to estimates of outcomes' likelihood based on how easy
they are to imagine — and to policies that ignore societal benefit.
This article discusses several clinical situations (
including silicone breast implants and autoimmune disease where no
evidence-based data exists for an association) where the public outcry from a
small number of patients who were extremely media savvy and with strong legal
connections were able to sway not only public health policy but also medical
and legal opinions. An interesting read if you have a specific interest.
There are several quotations from this article which
need to be considered:
1. From a policy perspective, the FDA has a
mandate to keep the public safe, but medical products are associated with two
types of risk: that caused by using the products and that caused by preventing
their use. In making regulatory decisions, the FDA considers both, but
political pressure focuses more on the former than the latter.
2. It’s worth considering how anecdote can skew
risk perception, leading to estimates of the likelihood of outcomes based on
how easy they are to imagine.
3. Yet our capacity to speak science to emotion
seems to be collapsing. As our patient-safety focus intensifies and physicians’
behaviour is publicly dissected, a story that goes viral has outsized power.
4. Autonomy implies the right to choose something
you want as well as the right to refuse something you don’t
