Spontaneous osteonecrosis of the knee and medial meniscal tears

Several factors may play a role in the etiology of "spontaneous" osteonecrosis of the medial femoral condyle. Corticosteroids are known to induce osteonecrosis, and 45% of the patients in this study received steroids parenterally or by intra-articular injection. Another factor, heretofore given little attention, is the association of medial meniscal tears and "spontaneous" osteonecrosis. Twenty-one (78%) of 27 knees examined by arthrography demonstrated meniscal tears. Stress concentration over the edge of the meniscal fragment may result in ischemic necrosis of the femoral condyle. Early detection of a medial meniscal tear by arthrography in older patients and prompt treatment may be important in avoiding the late changes of "spontaneous" osteonecrosis.     

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In summary, the naturopathic approach would treat this patient with dietary modification, nutritional and herbal supplements, regular preventive nasal irrigation, and adjunctive therapies such as homeopathy and osteopathic manipulation as indicated. Hopefully, this preventive approach will reduce or eliminate the need for the use of antibiotics to treat the acute exacerbations of what is really a chronic, lifestyle-related condition. As illustrated here, the Naturopathic Therapeutic Order can both guide us in treating a specific condition and assist us in assessing our patients on an individual, prevention-oriented basis.     

Site-directed mutagenesis of the human D antigen: definition of D epitopes on the sixth external domain of the D protein expressed on K562 cells

BACKGROUND: The antigens of the human Rh system are of great clinical significance in transfusion medicine and pregnancy. Of the Rh system antigens, D is clinically the most important, being one of the most immunogenic structures arising from human cells. The human D antigen represents a collection of epitopes expressed on a red cell membrane protein that is predicted to have 12 membrane-spanning segments giving rise to six exofacial domains. STUDY DESIGN AND METHODS: By site-directed mutagenesis using the method of inverse polymerase chain reaction, cE and D cDNA mutant constructs were generated with changes to the RHD-specific residues 350, 353, and 354 in the predicted sixth exofacial loop. Each mutant cDNA was subcloned into the pBabe puromycin retroviral vector, and supernatants were used to transduce K562 cells. Puromycin-resistant K562 clones were screened by flow cytometric analysis using a panel of monoclonal antibodies with specificities to ep (epitope) D1 through epD9. RESULTS: De novo expression of epD3 and epD9 was generated in the K562 cell lines expressing the mutated cE polypeptide (cE-Asp350His, Gly353Trp, Ala354Asn). Expression of c and E was unaffected. Conversely, the cells expressing the mutated D polypeptide demonstrated loss of expression of epD1, epD2, epD3, epD4, and epD9. CONCLUSION: The data provide strong evidence for the critical involvement of three amino acids, Asp₃₅₀, Gly₃₅₃, and Ala₃₅₄, in the expression of epD3 and epD9 on the predicted sixth external domain of the D protein. This domain also appears to be essential for the expression of epD1, epD2, and epD4, as a loss of expression of these epitopes was observed in K562 cells transduced with the D_mut construct (encoding His₃₅₀, Trp₃₅₃, and Asn₃₅₄). The K562/D_mut, cell line has an identical molecular and serologic profile as the red cell D^IVb pheno-type, which confirms that retroviral gene transfer of Rh cDNA into K562 cells provides us with a powerful means by which to further map epitopes of D.     

Extra-anatomical bypass grafting �C a single surgeon's experience

INTRODUCTION

Extra-anatomical bypass grafting is a recognised method of lower limb re-vascularisation in high-risk patients who cannot tolerate aortic cross clamping, or in those with a hostile abdomen. We present a single surgeon series of such procedures and determine relevant outcomes.

PATIENTS AND METHODS

A retrospective review was performed on a prospectively maintained database of patients undergoing femoro-femoral or axillo-femoral bypass surgery between 1986 and 2004.

RESULTS

Patency rates for femoral (n = 28; 32%) versus axillary (n = 59; 68%) bypass procedures at 1 month, 1, 3 and 5 years were (92% vs 93%), (69% vs 85%), (60% vs 72%) and (55% vs 67%), respectively. Patient survival rates for the corresponding procedures and time intervals were (96% vs 90%), (96% vs 67%), (85% vs 45%) and (73% vs 38%) and revealed a significantly lower survival rate in those undergoing axillary procedures (P = 0.002). Limb salvage rates were calculated at (100% vs 91%), (96% vs 84%), (96% vs 81%) and (92% vs 81%) with no statistically significant difference found between the two groups (P = 0.124). Two-thirds of the patients who required major amputation died within 12 months of surgery.

CONCLUSIONS

Acceptable 30-day morbidity, long-term primary patency and survival rates are obtainable in patients suitable for extra-anatomical bypass surgery despite having significant co-morbidities. We have shown 5-year patency rates in those that survive axillary procedures to be as good as those undergoing femoral procedures. Furthermore, surviving patients who evade amputation within a year have an excellent chance of long-term limb salvage.     

Surgical treatment of accessory atrioventricular pathways and symptomatic tachycardia in children and young adults

Twenty-seven patients aged 21 years or younger (mean 15) with symptomatic tachycardia underwent operation for ablation of an accessory atrioventricular pathway. Six patients had associated Ebstein's malformation of the tricuspid valve. Supraventricular tachycardia had been present for a mean of 5 years. At electrophysiologic study, 4 patients were found to have 2 accessory pathways. Left ventricular free wall pathways were found In 14 patients, right ventricular free wall pathways in 10 and septal pathways in 6. Successful initial ablation of all the pathways was achieved in 26 of the 27 patients. No patient died perioperatively and none had persistent complete heart block. During a mean follow-up of 11 months, no patient had recurrence of an arrhythmia related to the accessory pathway. Thus, the surgical treatment of children and young adults with accessory atrioventricular pathways and symptomatic supraventricular tachycardia is safe and effective. For these patients, unless the tachycardia can be easily controlled with a minimal number of drugs and adverse effects, surgical ablation should be considered early in the clinical course.