Systemic inhibition or global deletion of CaMKK2 protects against post-traumatic osteoarthritis

OBJECTIVE

To investigate the role of Ca^2+/calmodulin-dependent protein kinase 2 (CaMKK2) in post-traumatic osteoarthritis (PTOA).

METHODS

Destabilization of the medial meniscus (DMM) or sham surgeries were performed on 10-week-old male wild-type (WT) and Camkk2^-/- mice. Half of the DMM-WT mice and all other cohorts (n = 6/group) received tri-weekly intraperitoneal (i.p.) injections of saline whereas the remaining DMM-WT mice (n = 6/group) received i.p. injections of the CaMKK2 inhibitor STO-609 (0.033 mg/kg body weight) thrice a week. Study was terminated at 8- or 12-weeks post-surgery, and knee joints processed for microcomputed tomography imaging followed by histology and immunohistochemistry. Primary articular chondrocytes were isolated from knee joints of 4-6-day-old WT and Camkk2^-/- mice, and treated with 10 ng/ml interleukin-1β (IL)-1β for 24 or 48 h to investigate gene and protein expression.

RESULTS

CaMKK2 levels and activity became elevated in articular chondrocytes following IL-1β treatment or DMM surgery. Inhibition or absence of CaMKK2 protected against DMM-associated destruction of the cartilage, subchondral bone alterations and synovial inflammation. When challenged with IL-1β, chondrocytes lacking CaMKK2 displayed attenuated inflammation, cartilage catabolism, and resistance to suppression of matrix synthesis. IL-1β-treated CaMKK2-null chondrocytes displayed decreased IL-6 production, activation of signal transducer and activator of transcription 3 (Stat3) and matrix metalloproteinase 13 (MMP13), indicating a potential mechanism for the regulation of inflammatory responses in chondrocytes by CaMKK2.

CONCLUSIONS

Our findings reveal a novel function for CaMKK2 in chondrocytes and highlight the potential for its inhibition as an innovative therapeutic strategy in the prevention of PTOA.

Treatment of multifocal lymphoma of bone with intensified ProMACE-CytaBOM chemotherapy and involved field radiotherapy

Primary bone involvement is an unusual extranodal presentation of non-Hodgkin lymphoma (NHL). The optimal treatment for this entity has not been determined. While solitary bone lymphomas can be eradicated with local radiation in 50% of patients, distant relapses occur frequently, and the treatment of patients with multifocal osseous disease, or those presenting with associated soft tissue invasion or adenopathy is even less satisfactory. Over a 4-year period, nine patients with multifocal bone lymphoma were treated with intensified versions of the ProMACE-CytaBOM regimen and involved-field radiation. Seven patients had diffuse large cell histology and two patients had diffuse mixed type. Seven patients survived event-free at a median follow-up of 2.3 years (range .5-3.5). In most survivors, there was little or no change in the abnormal radiographic bone findings despite the clinical response to therapy. In one patient, magnetic resonance imaging (MRI) established that bone infarction rather than relapse of lymphoma was the cause of a new lytic bone lesion that developed during treatment.

Pityriasis rubra pilaris and focal acantholytic dyskeratosis

A 65-year-old man presented with a widespread erythematous maculopapular eruption. Skin biopsy showed spongiosis and focal acantholytic dyskeratosis consistent with Grover's disease. Clinically the eruption evolved to erythroderma with typical features of pityriasis rubra pilaris. On review of the histology, changes consistent with this diagnosis were also present in addition to the acantholytic dyskeratosis.

The contribution of direct immunofluorescence to the diagnosis of lupus erythematosus

The contributions of direct immunofluorescence, light microscopy and serology to the investigation of 52 patients with possible lupus erythematosus were studied. Direct immunofluorescence was found to be most valuable in the investigation of possible systemic lupus erythematosus whilst only of supportive value in the investigation of possible chronic discoid lupus erythematosus. The importance of performing light microscopy before direct immunofluorescence in cases of possible chronic discoid lupus erythematosus is shown.

The staphylococcal scalded skin syndrome in two elderly immunocompromised patients

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Clinical evaluation of a new nonelectronic all-in-the-ear hearing device for mild hearing loss

A new, nonelectronic hearing aid was studied in 112 patients with mild sloping sensorineural hearing loss. The device, worn all in the ear and made of clear plastic, produced a mean functional gain of 9.6 dB at 1500 Hz, 12.4 dB at 1750 Hz, and 9.1 dB at 2000 Hz, with lesser gains at adjacent frequencies between 1000 and 2500 Hz. Speech discrimination in quiet and in noise was improved. Patient acceptance of the device (in a group of 884 patients) was 76%. The device appears to be useful in the treatment of mild hearing loss.

Complications of silicone implants in foot surgery

Silicone rubber arthroplasty has been used in the foot with great success and with devastating failure. In an effort to understand why certain cases are successes and why certain cases are failures, a systematic investigation of several factors is necessary. A certain relationship exists among the material of which the implant is made, the design of the implant and the function it is asked to perform, and the host response to the material or implant. Simply because a material has been shown inert when placed in relatively large pieces in the body is not reason enough to support its use. The design of the implant must be such that it re-establishes function parallel to an anatomic manner. Host response to a prosthesis may be viewed in light of the tissue response to the foreign body and also with regard to its effect on bone, synovium, and articular cartilage as an organ. One must consider not only biologic compatibility but also compatibility of physical properties and physiologic function. This article has attempted to address and organize implant surgery in just this manner described. Silicone rubber arthroplasty has been a very satisfying procedure for both patient and surgeon. Complications do occur, and it is up to the surgeon to provide the analysis. The manufacturer may provide the prosthesis but the responsibility lies with the surgical community to use implantation in a proper and appropriate manner.