What’s new in March for Medicine features: Heart Failure, Red Blood Cell Function and Disorders of Iron Metabolism, Hemostasis and its Regulation, Cognitive Disorders Other Than Alzheimer Disease, Fibromyalgia.
SACHIN P. SHAH, MD
MANDEEP R. MEHRA, MD
Center for Advanced Heart Disease, Brigham and Women’s Hospital Heart and Vascular Center, Harvard Medical School, Boston, MA
Abdominal Compartment in Heart Failure
Emerging evidence is refining an understanding of the role of the splanchnic circulation and the abdominal compartment in heart failure. The abdominal organs and splanchnic circulation appear to play an active role in volume distribution and renal filtration, thereby affecting balance between a compensated and a decompensated state. The understanding of the homeostatic role of the abdominal compartment in the compensated state and the maladaptive role in the decompensated state is evolving and may provide targets for new therapies and better application of available treatment strategies in the future.
ROBERT T. MEANS JR, MD, FACP
Office of the Dean, James H. Quillen College of Medicine, East Tennessee State University, Johnson City, TN
Iron deficiency is the most common nutritional deficiency worldwide. Its prevalence is highest in the less developed world, where 30 to 70% of the population may be affected; in comparison, the overall prevalence of iron deficiency is less than 20% in Europe and North America. This reflects both nutritional and economic issues, as well as endemic medical problems such as hookworm infestation. In all populations, the prevalence is greatest in women of childbearing years and children. In the United States, the Centers for Disease Control and Prevention estimates that the prevalence of iron deficiency is greatest in toddlers 1 to 2 years of age (7%) and in adolescent girls and adult women 12 to 49 years of age (9 to 16%).
LAWRENCE L.K. LEUNG, MD
Stanford University School of Medicine, Chief of Staff, Veterans Affairs Palo Alto Health Care System, Stanford, CA
New Tests in Hemostasis
Two new tests are now available: thromboelastography and the thrombin generation test. Both assays provide much more information than the conventional clotting times (e.g., clotting times generally correlate only with the lag time in the thrombin generation process; thus, the bulk of information related to thrombin generation is not measured). Also, new generations of devices allow both tests to be performed in an automated manner, leading to greater reproducibility and less variation among laboratories. Currently, both tests are still available only in special clinical coagulation laboratories, but it is anticipated that they will become more widely available in the near future. Whether these new assays will have the required sensitivity and specificity to deliver superior diagnostic utility remains to be established.
SETH A. GALE, MD
KIRK R. DAFFNER, MD, FAAN
Division of Cognitive and Behavioral Neurology, Brigham and Women’s Hospital, J. David and Virginia Wimberly Professor of Neurology, Harvard Medical School, Boston, MA
Frontotemporal Lobar Degeneration
The pathogenesis of frontotemporal lobar degeneration (FTLD) is complicated, and continued research is needed to fully explain the physiology. Interestingly, some evidence has suggested that developmental, language-based learning disabilities are also associated with patterns of handedness and hemispheric language dominance and may increase the risk of later-life primary progressive aphasia (PPA), which is a clinical syndrome characterized by initial and prominent language-based cognitive deficits. This raises the notion that in some cases, PPA or FTLD may arise as a delayed manifestation of long-standing vulnerability in a specific brain region, which then becomes a natural starting point for a degenerative process.
DANIEL JOSEPH CLAUW, MD
Chronic Pain and Fatigue Research Center, University of Michigan, Ann Arbor, MI
Peripheral Pain Treatment in Fibromyalgia
Although fibromyalgia (FM) is still generally thought not to be due to peripheral damage or inflammation, there is emerging evidence that identifying and treating peripheral pain generators may be helpful, perhaps because peripheral nociceptive input is known to drive central sensitization. A recent study has shown that individuals with FM with comorbid osteoarthritis or myofascial pain had improvement in their overall FM pain and tenderness when these were treated with local therapies. There is also emerging evidence that some individuals with FM exhibit a small fiber neuropathy on biopsy, although the treatment implications of this finding are still not clear.
As seen in Scientific AmericanTM Medicine.
Figure of the Month: The Figure of the Month for March is entitled Model of Hemoglobin Molecule (Figure 1 from Red Blood Cell Function and Disorders of Iron Metabolism).