The 11th edition of Harrison's Principles of Internal Medicine welcomes Anthony Fauci to its editorial staff, in addition to more than 85 new contributors. While the organization of the book is similar to previous editions, major emphasis has been placed on disorders that affect multiple organ systems. Important advances in genetics, immunology, and oncology are emphasized. Many chapters of the book have been rewritten and describe major advances in internal medicine. Subjects that received only a paragraph or two of attention in previous editions are now covered in entire chapters. Among the chapters that have been extensively revised are the chapters on infections in the compromised host, on skin rashes in infections, on many of the viral infections, including cytomegalovirus and Epstein-Barr virus, on sexually transmitted diseases, on diabetes mellitus, on disorders of bone and mineral metabolism, and on lymphadenopathy and splenomegaly. The major revisions in these chapters and many

Harrison's Principles of Internal Medicine

Articular cartilage is the highly specialized connective tissue of diarthrodial joints. Its principal function is to provide a smooth, lubricated surface for articulation and to facilitate the transmission of loads with a low frictional coefficient (Figure 1). Articular cartilage is devoid of blood vessels, lymphatics, and nerves and is subject to a harsh biomechanical environment. Most important, articular cartilage has a limited capacity for intrinsic healing and repair. In this regard, the preservation and health of articular cartilage are paramount to joint health.



Figure 1.

Gross photograph of healthy articular cartilage in an adult human knee.



Injury to articular cartilage is recognized as a cause of significant musculoskeletal morbidity. The unique and complex structure of articular cartilage makes treatment and repair or restoration of the defects challenging for the patient, the surgeon, and the physical therapist. The preservation of articular cartilage is highly dependent on maintaining its organized architecture.

/pdf/the-basic-science-of-articular-cartilage-structure-3mc2a5lzti.pdf

The basic science of articular cartilage: structure, composition, and function

https://www.thelancet.com/pdfs/journals/lancet/PIIS0140-6736(11)60243-2.pdf

Osteoarthritis: an update with relevance for clinical practice

Context Duration of untreated psychosis (DUP) is the time from manifestation of the first psychotic symptom to initiation of adequate treatment. It has been postulated that a longer DUP leads to a poorer prognosis. If so, outcome might be improved through earlier detection and treatment. Objectives To establish whether DUP is associated with prognosis and to determine whether any association is explained by confounding with premorbid adjustment. Data Sources The CINAHL (Cumulative Index to Nursing and Allied Health), EMBASE, MEDLINE, and PsychLIT databases were searched from their inception dates to May 2004. Study Selection Eligible studies reported the relationship between DUP and outcome in prospective cohorts recruited during their first episode of psychosis. Twenty-six eligible studies involving 4490 participants were identified from 11 458 abstracts, each screened by 2 reviewers. Data Extraction Data were extracted independently and were checked by double entry. Sensitivity analyses were conducted excluding studies that had follow-up rates of less than 80%, included affective psychoses, or did not use a standardized assessment of DUP. Data Synthesis Independent meta-analyses were conducted of correlational data and of data derived from comparisons of long and short DUP groups. Most data were correlational, and these showed a significant association between DUP and several outcomes at 6 and 12 months (including total symptoms, depression/anxiety, negative symptoms, overall functioning, positive symptoms, and social functioning). Long vs short DUP data showed an association between longer DUP and worse outcome at 6 months in terms of total symptoms, overall functioning, positive symptoms, and quality of life. Patients with a long DUP were significantly less likely to achieve remission. The observed association between DUP and outcome was not explained by premorbid adjustment. Conclusions There is convincing evidence of a modest association between DUP and outcome, which supports the case for clinical trials that examine the effect of reducing DUP.

/pdf/association-between-duration-of-untreated-psychosis-and-3d33a68pa1.pdf

Association Between Duration of Untreated Psychosis and Outcome in Cohorts of First-Episode Patients: A Systematic Review

Longitudinal studies of cognition and functional outcome in schizophrenia: implications for MATRICS.

A quantitative meta-analysis of brain glutamate metabolites in aging.

17O-Decoupled Proton MR Spectroscopy and Imaging in a Tissue Model

The sensitivity of in vivo MRS of the N-delta proton of the proximal histidine of deoxymyoglobin in human skeletal muscles is discussed. Longitudinal relaxation time T1 of this deoxymyoglobin signal was measured in cuffed human forearms at 1.5 T and found to be 9.9 ms. Deoxymyoglobin spectra can be obtained from a forearm in seconds. The detection sensitivity of deoxymyoglobin in fully ischemic skeletal muscles and that of 31P MRS of PCr in normal resting muscles are compared.

Sensitivity of in vivo MRS of the N-δ proton in proximal histidine of deoxymyoglobin

In this work, the feasibility of using T2ρ weighting as an MR contrast mechanism is evaluated. Axial images of a human brain were acquired using a single-slice spin-lock T2ρ-weighted pulse sequence and compared to analogous T2-weighted images of the same slice. The contrast between white matter and gray matter in T2ρ-weighted images was approximately 40% greater than that from T2-weighted data. These preliminary data suggest that the novel contrast mechanism of T2ρ can be used to yield high-contrast T2-like images. Magn Reson Med 52:1223–1227, 2004. © 2004 Wiley-Liss, Inc.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mrm.20284

T2ρ-weighted contrast in MR images of the human brain

Proton exchange imaging is important as it allows for visualization and quantification of the distribution of specific metabolites with conventional MRI. Current exchange mediated MRI methods suffer from poor contrast as well as confounding factors that influence exchange rates. In this study we developed a new method to measure proton exchange which combines chemical exchange saturation transfer and T1ρ magnetization preparation methods (CESTrho). We demonstrated that this new CESTrho sequence can detect proton exchange in the slow to intermediate exchange regimes. It has a linear dependence on proton concentration which allows it to be used to quantitatively measure changes in metabolite concentration. Additionally, the magnetization scheme of this new method can be customized to make it insensitive to changes in exchange rate while retaining its dependency on solute concentration. Finally, we showed the feasibility of using CESTrho in vivo. This sequence is able to detect proton exchange at intermediate exchange rates and is unaffected by the confounding factors that influence proton exchange rates thus making it ideal for the measurement of metabolites with exchangeable protons in this exchange regime. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.

https://onlinelibrary.wiley.com/doi/pdf/10.1002/mrm.23213

Investigation of chemical exchange at intermediate exchange rates using a combination of chemical exchange saturation transfer (CEST) and spin‐locking methods (CESTrho)

Ravinder Reddy

Papers

A quantitative meta-analysis of brain glutamate metabolites in aging.

17O-Decoupled Proton MR Spectroscopy and Imaging in a Tissue Model

Sensitivity of in vivo MRS of the N-δ proton in proximal histidine of deoxymyoglobin

T2ρ-weighted contrast in MR images of the human brain

Investigation of chemical exchange at intermediate exchange rates using a combination of chemical exchange saturation transfer (CEST) and spin‐locking methods (CESTrho)