Osteochondritis dissecans in a cat?

How do phosphodiesterase-5 inhibitors affect cancer? A focus on glioblastoma multiforme

Since the discovery of phosphodiesterase-5 (PDE5) enzyme overexpression in the central nervous system (CNS) malignancies, investigations have explored the potential capacity of current PDE5 inhibitor drugs for repositioning in the treatment of brain tumors, notably glioblastoma multiforme (GBM). It has now been recognized that these drugs increase brain tumors permeability and enhance standard chemotherapeutics effectiveness. More importantly, studies have highlighted the promising antitumor functions of PDE5 inhibitors, e.g., triggering apoptosis, suppressing tumor cell growth and invasion, and reversing tumor microenvironment (TME) immunosuppression in the brain. However, contradictory reports have suggested a pro-oncogenic role for neuronal cyclic guanosine monophosphate (cGMP), indicating the beneficial function of PDE5 in the brain of GBM patients. Unfortunately, due to the inconsistent preclinical findings, only a few clinical trials are evaluating the therapeutic value of PDE5 inhibitors in GBM treatment. Accordingly, additional studies should be conducted to shed light on the precise effect of PDE5 inhibitors in GBM biology regarding the existing molecular heterogeneities among individuals. Here, we highlighted and discussed the previously investigated mechanisms underlying the impacts of PDE5 inhibitors in cancers, focusing on GBM to provide an overview of current knowledge necessary for future studies.

Stifle osteochondritis dissecans in snow leopards (Uncia uncia)

Three snow leopard (Uncia uncia) cubs, female and male siblings and an unrelated female, had lameness attributed to osteochondritis dissecans (OCD) lesions noted at 6, 8, and 10 mo of age, respectively. All cubs were diagnosed with OCD via radiographs. The sibling cubs both had lesions of the right lateral femoral condyles, while the unrelated cub had bilateral lesions of the lateral femoral condyles. Subsequently, OCD was confirmed in all three cases during surgical correction of the lateral femoral condyle lesions via lateral stifle arthrotomies, flap removal, and debridement of the defect sites. Histopathology also supported the diagnosis of OCD. Postoperatively, the sibling cubs developed seromas at the incision sites and mild lameness, which resolved within a month. To date, two cubs have been orthopedically sound, while one of the sibling cubs has developed mild osteoarthritis. OCD has rarely been reported in domestic felids, and to the authors' knowledge these are the first reported cases of OCD in nondomestic felids.

Arthroscopic-assisted management of osteochondritis dissecans in the stifle of a cat

An 11-month-old, male neutered, domestic short-haired cat presented for evaluation of sudden onset right pelvic limb lameness. Radiography showed features consistent with unilateral osteochondritis dissecans (OCD) of the lateral femoral condyle in the right stifle. Arthroscopic examination of the stifle was used to confirm the presence of an articular cartilage lesion and the presence of loose cartilage within the joint. The loose cartilage fragments were removed arthroscopically. One arthroscopy portal was extended into a limited arthrotomy, which was necessary to ensure complete debridement of the defect. Removal of the fragments led to complete resolution of the clinical signs. This case report documents a more minimally invasive technique for the management of stifle OCD in the cat than previously documented and helps to establish a protocol for arthroscopic surgery in the feline stifle.

Bilateral Stifle Osteochondritis Dissecans in a Cat

A 9-month-old, castrated male, domestic shorthaired cat was presented for progressive right hind-limb lameness. A diagnosis of osteochondritis dissecans of the lateral femoral condyle was made based on radiographs and physical examination, and was confirmed by right lateral stifle arthrotomy. The cartilage flap was removed, and the underlying bone was curetted. Seven months later, the cat was sound on the right leg but developed a left hind-limb lameness. A similar lesion was found in the left leg and was treated identically. Fourteen months after presentation, the cat was sound on both hind limbs.