Professor
Brian Andrews NEJM Recommendations for Medical Students and Tutors
Week
of 19th May 2016 (#43)
University
of Notre Dame Australia (Fremantle Campus)
Occasional Editorial Comment
I have been on vacation for four weeks and am a little
behind in my weekly review.
Currently, although the e-mail is sent to a large
number of recipients, the only feedback I receive as to the number of people
reading the e-mail, is when a recipient enters the blog at the bottom of the review.
I would be most appreciative, if on opening this week’s
e-mail and subsequent e-mails, you would also open the blog at the bottom of
the page.
I am also sending you a very brief survey comprising
seven short questions on SurveyMonkey
to determine the demographics and interest of my readership and its usefulness
to the recipients https://www.surveymonkey.com/r/Andrews_NEJM_feedback .
I
thank you in advance for filling out this survey.
.
Must Read Articles
REVIEW ARTICLE
Coronary-Artery
Bypass Grafting
Coronary-artery
bypass grafting (CABG) is very commonly performed. CABG improves survival among
patients with multivessel coronary disease; those with more severe coronary
disease, diabetes, or left ventricular dysfunction are especially likely to
benefit.
This is an excellent review for the current indications
for CABG, as well as the technical aspects and future directions.
Articles Recommended for Medical Students
IMAGES IN CLINICAL MEDICINE
Splenosis
Mimicking Cancer
A
62-year-old woman with shortness of breath and a history of smoking was
referred for pulmonary evaluation when chest radiography showed nodularity
along the left hemidiaphragm. Her history was notable for a gunshot wound to
the thoracoabdominal region 28 years earlier.
This is an interesting CXR and CT demonstrating
splenosis following previous thoraco-abdominal trauma associated with splenic
trauma and splenectomy (Splenosis: A Review South Med J. 2007;100(6):589-593)
IMAGES IN CLINICAL MEDICINE
Loose
Teeth and Excessive Thirst
A
36-year-old man presented with oral pain and loose teeth; four teeth had been
lost spontaneously within the 6 months before presentation. Increased thirst
and urination had developed during the preceding 4 months. Blood electrolyte
levels revealed hypernatremia and dehydration.
Without the radiological findings, I have seen this
presentation with granulomatosis with polyangiitis (Wegener’s granulomatosis)
and hyperparathyroidism.
CASE RECORDS OF THE MASSACHUSETTS GENERAL HOSPITAL
Case
15-2016 — A 32-Year-Old Man with Olfactory Hallucinations and Paresthesias
A 32-year-old man presented with a
1-year history of olfactory hallucinations and a 6-week history of intermittent
numbness and paresthesias on the left side. MRI revealed a nodular focus of
enhancement in the medial right temporal lobe. A diagnostic procedure was
performed.
This CPC presents a patient with a right temporal lobe
lesion and discusses the differential diagnoses of malignant and non-malignant
lesions at this site. Significant time
is devoted to the management of the disorder.
Recommended
learning: Review the neurobiology of the temporal lobe,
pathological lesions that involve the temporal lobe and their clinical
presentations, and temporal lobe seizures and their management.
ORIGINAL ARTICLE
Rate
Control versus Rhythm Control for Atrial Fibrillation after Cardiac Surgery
In
this study involving patients with new-onset postoperative atrial fibrillation
who received either rate control or rhythm control, there was no significant
difference in rates of hospitalization, complications, or persistent atrial
fibrillation 60 days after onset.
EDITORIAL
Is
Less More for the Treatment of Atrial Fibrillation after Cardiac Surgery?
In the study, 33% of patients (695 of 2109 from medical
centres in the US and Canada) undergoing cardiac surgery developed
post-operative atrial fibrillation (AF). Patients with AF were randomized into
those receiving either rate control or rhythm control (amiodarone). If AF
persisted for greater than 48 hours the patients were anticoagulated with
warfarin for 60 days.
The results indicated that there was no clinically
significant differences between the groups with 84 -87% without AF at discharge
and 94 – 98% without AF at 60 days. However, the author of the editorial from
Johns Hopkins suggests that the data favour that all patients be treated
initially with rate control. He suggested that rhythm control be used only for
those patients who are significantly symptomatic, hemodynamically unstable, or
those in whom rate control cannot be achieved.
Important Articles Related to Mechanisms of Disease and
Translational Research
None
Other Articles which should interest medical students
ORIGINAL ARTICLE
Danazol
Treatment for Telomere Diseases
In
a study designed to assess whether danazol could slow the rate of telomere
attrition in a group of patients with short telomeres, 11 of 12 patients
actually had telomere elongation over 24 months of therapy
EDITORIAL
Telomeres
on Steroids — Turning Back the Mitotic Clock?
Telomeres are repetitive nucleotide sequences at the
ends of linear chromosomes which protect the ends of the chromosomes from
breakdown. Aging is associated with reduction in telomere length, which begins
in the first year of life particularly in all leukocytes except memory B cells.
Regeneration of telomeres is achieved by telomerase (telomerase reverse
transcriptase and the telomerase RNA template gene). The prototype of the
genetic “telomerase maintenance” disorders is the rare dyskeratosis congenita,
although the commonest disorder in younger patients is aplastic anaemia and in
patients older than 30 years is pulmonary fibrosis. These disorders are associated with an
increased frequency of malignancy.
Historically male anabolic steroids have been used in
the treatment of bone marrow failure with varying success rates. Studies have
suggested that male anabolic hormones directly regulate telomerase. Further,
postmenopausal females treated with HRT have longer telomeres.
This is an interesting study of 27 patients, 25 of whom
had evidence of bone marrow failure, 25 had pulmonary fibrosis, and 9 had
evidence of cirrhosis. Twenty one of 27 had documented mutations in the
telomerase gene and 23 had a family history of telomeropathy. All patients were
treated with the synthetic male sex hormone danazol for 24 months and then
followed for a further 12 months. The primary end point was a 20% reduction in
the annual rate of telomere attrition measured at 24 months.
As 11 of the first 12 patients studied at 24 months in fact
had elongation of telomere length, rather than the predicted loss (Fig 1B), the
study was stopped. When these 12 patients were followed from 24 to 36 months,
the telomere length then decreased (see Fig 1 and table 2). There was also a
parallel clinical improvement with reduced requirements for RBC and platelets
and a stabilization in the DLCO of patients with pulmonary fibrosis. Long term
studies regarding preservation of telomere length, anabolic steroids, and
clinical improvement (especially prevention of malignancy) are eagerly awaited.
Recommended
learning: Review the biology of telomeres and telomerase
activity.
SPECIAL REPORT
Zika Virus and Birth Defects — Reviewing the Evidence
for Causality
Zika virus has spread rapidly throughout the Americas over the past year. In this report, CDC authors determine that the evidence level has exceeded the threshold to assign causation between prenatal exposure and microcephaly and to declare Zika virus a teratogen.
This is a well-constructed special report on the Zika
virus which focuses on the evidence for causality. The report adopts the hypothesis
that Zika virus infection during pregnancy is responsible for microcephaly and
marked neurological impairment. This hypothesis is analysed using Shepard’s
criteria for proof of teratogenicity in humans and the Bradford Hill Criteria
for evidence of causation.
The conclusion is that there is now sufficient
scientific evidence to infer a causal relationship between prenatal Zika virus
infection and microcephaly and significant neurological impairment.
