Evidence for cometabolic transformation of weathered toxaphene under aerobic conditions using camphor as a co-substrate

AIMS

Toxaphene is a persistent organic pollutant, composed of approximately 1000 highly chlorinated bicyclic terpenes. The purpose of this study was to evaluate if camphor, a structural analogue of toxaphene, could stimulate aerobic biotransformation of weathered toxaphene.

METHODS AND RESULTS

Two enrichment cultures that degrade camphor as the sole carbon source were established from contaminated soil and biosolids. These cultures were used to evaluate aerobic transformation of weathered toxaphene. Only the biosolids culture could transform compounds of technical toxaphene (CTTs) in the presence of camphor, while no transformation was observed in the presence of glucose or with toxaphene as a sole carbon source. The transformed toxaphene had lower concentration of CTTs with longer retention times, and higher concentration of compounds with lower retention times. Gas chromatography with electron capture negative ion mass spectrometry (GC/ECNI-MS) showed that aerobic biotransformation mainly occurred with Cl₈ - and Cl₉ -CTTs compounds. The patterns of Cl₆ - and Cl₇ -CTTs were also simplified albeit to a much lesser extent. Seven camphor-degrading bacteria were isolated from the enrichment culture but none of them could degrade toxaphene.

CONCLUSION

Camphor degrading culture can aerobically transform CCTs via reductive pathway probably by co-metabolism using camphor as a co-substrate.

SIGNIFICANCE AND IMPACT OF THE STUDY

Since camphor is naturally produced by different plants, this study suggests that stimulation of aerobic transformation of toxaphene may occur in nature. Moreover plants, which produce camphor or similar compounds, might be used in bioremediation of contaminated soils.

Functional outcomes after prostatic cryosurgery

OBJECTIVE

To assess the functional effects of prostatic cryosurgery on micturition.

MATERIAL AND METHODS

Prospective study of men who underwent cryosurgery (CS) for prostate cancer between 2013 - 2015. Low urinary tract symptoms (LUTS) and quality of life (QoL) were assessed 1 month before surgery using IPSS questionnaire, a three-day voiding diary (3DVD) and uroflowmetry with ultrasound-measured postvoid residual volume. Need of medical treatment for LUTS was also recorded. The same assessment was performed at 3, 6 and 12 months after CS. Outcomes after surgery were compared to those prior to surgery.

RESULTS

Forty-five patients underwent a CS during the study period, of whom 25 patients could be recruited in the study. Mean age was 73.5 years (range 66-84). Nineteen CS (76%) were performed as a primary procedure, while 6 CS (24%) as a salvage procedure. No statistical differences were found comparing results of IPSS, QoL, D3vd or uroflowmetry and PVR at 3, 6 or 12 months after CS compared to before surgery. Before CS, 8 (32%) patients were on medical treatment for LUTS, while at 6 and 12 months after surgery, 3 (13.6%) and 2 (9.5%) patients required some medication, respectively.

CONCLUSION

According to the punctuation of IPSS, QoL questionnaire, and a 3-day voiding diary, LUTS does not worsen after CS. Prostatic cryosurgery does not seem to impact uroflowmetry results.

Heterosexual transmission of HIV-1 is associated with high plasma viral load levels and a positive viral isolation in the infected partner

Risk factors for heterosexual HIV transmission are not fully understood. In fact, a proportion of people with sexual exposure to HIV remain uninfected despite multiple and continuous intercourse with HIV-infected partners. In this work, we have analyzed those virologic parameters potentially involved in the transmission of HIV through heterosexual contact. Thirty-eight couples with continuous unprotected sexual intercourse were included. HIV transmission occurred in 10 of 38 couples. No differences in clinical characteristics, exposure time, sexual practices, CD4 counts, or polymorphism in CCR5 were found between transmitter and nontransmitter groups. In contrast, virologic data were different between both groups; median values of viral load were 21.139 and 5.484 RNA copies/ml of plasma in the transmitter and nontransmitter groups, respectively, and a significant difference was found in mean viral load values (p = .03, Mann-Whitney test). Viral isolation was obtained in 90% of transmitters, but in only 44% of nontransmitter subjects (p = .02, Fisher's exact test). These data show that viral load levels and a positive viral isolation in culture must be considered as risk factors for heterosexual transmission of HIV-1.

Bacteremia following liver biopsy in transplant recipients with Roux-en-Y choledochojejunostomy

Between 1990 and 1995, 666 percutaneous liver biopsies were performed in 196 patients at Gregorio Marañón General Hospital (mean 3.4 biopsies/patient); 533 biopsies (80.03%) were carried out in patients with choledochostomy biliary anastomosis and 133 (19.97%) in patients with choledochojejunostomy. Infectious complications, in the form of sepsis, occurred in two patients, who recovered favorably with antibiotic therapy. These two patients had undergone Roux-en-Y choledochojejunostomy (1.5%, not significant). Our findings suggest that the incidence of infectious complications after liver biopsy in transplant recipients is very low. Antibiotic prophylaxis at the time of liver biopsy in patients with Roux-en-Y choledochojejunostomy may decrease the frequency of infectious complications.