Biliopancreatic diversion in a renal transplant patient.

Surgery is usually the only solution to modify the evolution of morbid obesity and resolve the associated co-morbidities. There is very little written regarding malabsorptive surgery and transplantation. A 48-year-old male with hypertension, hyperuricemia and obesity underwent renal transplantation in 1994 for renal amyloidosis. He was maintained on oral immunosuppressive cyclosporine. The patient developed uncontrollable hypertension, hyperlipemia, hyperglycemia and increasing weight to a BMI of 44. Thus, in December 2004, he underwent biliopancreatic diversion (BPD). After 18 months follow-up, he has lost 85% of his excess weight, and his hypertension, hyperglycemia and hyperlipemia are markedly improved. Renal function was not modified, nor were the levels of cyclosporine. He has had no complications derived from the BPD, and has a better quality of life.

Effects of weight loss after biliopancreatic diversion on metabolism and cardiovascular profile.

BACKGROUND: Obesity is associated with increased prevalence of cardiovascular risk factors. Biliopancreatic diversion (BPD) for morbid obesity has been reported to produce anemia and malnutrition in short-term follow-up. The aim of our study was to analyze the effect of weight reduction on cardiovascular profile, renal function and nutritional status. METHODS: 35 morbidly obese patients underwent BPD. We analyzed the presence of cardiovascular risk factors, renal status, proteinuria and nutritional status before and 1 year after BPD. RESULTS: Excess weight loss was 67% at 1 year after BPD. All cardiovascular risk factors (hypertension, diabetes, hyperlipidemia) improved during follow-up. We could not find any relevant signs of malnutrition in the patients. Microalbuminuria decreased and proteinuria disappeared after weight loss. We observed less urinary calcium and citrate excretion, with an increase in oxaluria, but these changes did not increase the incidence of renal stones. CONCLUSIONS: BPD was followed by improved cardiovascular profile and a lower pro-inflammatory state. BPD did not produce significant malnutrition, anemia or renal stone disease.

Structural dissection of a highly knotted peptide reveals minimal motif with antimicrobial activity.

The increasing occurrence of bacterial resistance to antibiotics is driving a renewed interest on antimicrobial peptides, in the hope that understanding the structural features responsible for their activity will provide leads into new anti-infective drug candidates. Most chemical studies in this field have focused on linear peptides of various eukaryotic origins, rather than on structures with complex folding patterns found also in nature. We have undertaken the structural dissection of a highly knotted, cysteine-rich plant thionin, with the aim of defining a minimal, synthetically accessible, structure that preserves the bioactive properties of the parent peptide. Using efficient strategies for directed disulfide bond formation, we have prepared a substantially simplified (45% size reduction) version with undiminished antimicrobial activity against a representative panel of pathogens. Analysis by circular dichroism shows that the downsized peptide preserves the central double alpha-helix of the parent form as an essential bioactive motif. Membrane permeability and surface plasmon resonance studies confirm that the mechanism of action remains unchanged.

Synthetic and structural studies on Pyrularia pubera thionin: a single-residue mutation enhances activity against Gram-negative bacteria.

The thionin from Pyrularia pubera (Pp-TH), a 47-residue peptide with four internal disulfide bonds, was efficiently produced by chemical synthesis. Its antimicrobial activity in vitro against several representative pathogens (EC(50)=0.3-3.0 microM) was identical to that of natural Pp-TH. This peptide has a unique Asp(32) instead of the consensus Arg found in other thionins of the same family. In order to evaluate the effect of this mutation, the Arg(32) analogue (Pp-TH(D32R)) was also synthesized and showed a significant increase in antibiotic activity against several Gram-negative bacteria, whereas it retained the same activity against other pathogens. The overall structure of Pp-TH(D32R) was maintained, though a slight decrease in the helical content of the peptide was observed.