A new β chain hemoglobin variant with increased oxygen affinity: Hb Santa Giusta Sardegna [β93(F9)Cys→Trp; HBB c.282T>G

During a screening program for the identification of β-thalassemia (β-thal) carriers in Sardinia, Italy, we identified two subjects with increased hemoglobin (Hb) levels and an abnormal Hb variant. The same variant was detected in a family member. DNA sequencing revealed a TGT > TGG mutation at codon 93 of the β-globin gene. Structural analysis demonstrated that the cystine residue at position 93 of the β chain was substituted by tryptophan. Since this amino acid substitution had not yet been reported, we designated this variant Hb Santa Giusta Sardegna for the place of birth of the subjects. This amino acid substitution occurs at the tyrosine pocket of the β chain as well as at the α1β2/α2β1 contact of the quaternary structure of the molecule. The presence of this Hb in the hemolysate causes an increased oxygen affinity, a slightly reduced Bohr effect and a reduced heme-heme interaction (n(50), Hill's constant) in comparison with those of Hb A.     

Hypericum-induced mood disorder: switch from depression to mixed episodes in two patients

Objective. To point out the danger of worsening mood disorders with the use of hypericum. Methods. Longitudinal clinical observation of two cases treated with hypericum. Results. The two patients underwent mixed episodes following hypericum treatment. One of them needed hospitalization for suicidal risk. Conclusion. Caution is warranted in the use of hypericum in depressed patients with hidden bipolarity. Patients should be informed that hypericum may induce manic symptoms, increase cycling of mood states, or worsen the depressive state.     

High Infection Rate Outcomes in Long-bone Tumor Surgery with Endoprosthetic Reconstruction in Adults: A Systematic Review

Background

Limb salvage surgery (LSS) with endoprosthetic replacement is the most common method of reconstruction following bone tumor resection in the adult population. The risk of a postoperative infection developing is high when compared with conventional arthroplasty and there are no appropriate guidelines for antibiotic prophylaxis.

Questions/purposes

We sought to answer the following questions: (1) What is the overall risk of deep infection and the causative organism in lower-extremity long-bone tumor surgery with endoprosthetic reconstruction? (2) What antibiotic regimens are used with endoprosthetic reconstruction? (3) Is there a correlation between infection and either duration of postoperative antibiotics or sample size?

Methods

We conducted a systematic review of the literature for clinical studies that reported infection rates in adults with primary bony malignancies of the lower extremity treated with surgery and endoprosthetic reconstruction. The search included articles published in English between 1980 and July 2011.

Results

The systematic literature review yielded 48 studies reporting on a total of 4838 patients. The overall pooled weighted infection rate for lower-extremity LSS with endoprosthetic reconstruction was approximately 10% (95% CI, 8%–11%), with the most common causative organism reported to be Gram-positive bacteria in the majority of cases. The pooled weighted infection rate was 13% after short-term postoperative antibiotics and 8% after long-term postoperative antibiotics. There was no correlation between sample size and infection rate.

Conclusions

Infection rates of 10% are high when compared with rates for conventional arthroplasty. Our results suggest that long-term antibiotic prophylaxis decreases the risk of deep infection. However, the data should be interpreted with caution owing to the retrospective nature of the studies.