Use of bilateral temporary nephrostomy catheters for emergency treatment of bilateral ureter transection in a cat

A 2-year-old Himalayan cat was examined because of 4 days of vomiting, lethargy; and anorexia. The cat had undergone hysterectomy and removal of left ovarian remnants 5 days earlier. Results of laboratory testing and excretory urography were consistent with uremia and bilateral ureteral obstruction. Nephrostomy catheters were placed to drain urine and allow time for physiologic diuresis prior to definitive repair. During the next 2 days, the cat's physiologic status improved greatly. The cat underwent exploratory surgery, and both ureters were found to be ligated. The healthy proximal portions of the ureters were implanted into the bladder. Six months after surgery, the cat was doing well, and excretory urography demonstrated that both ureters were patent. Bilateral obstruction of the ureters is a life-threatening condition that can be difficult to correct in cats. Placement of nephrostomy catheters allows time for improvement in the cat's physiologic status prior to the protracted anesthesia time needed for surgical repair of the ureters.

Biotreatment of PAH-contaminated soils/sediments

The importance of chemical conditions and mass transfer effects to in situ bioremediation of PAHs is presented using a case study. In situ bioremediation is being evaluated as a means for remediating a coal-tar contaminated aquifer at the site of a former manufactured gas plant. Two objectives of this work have been to evaluate the potential for the indigenous bacteria to biodegrade coal tar constituents and to identify factors controlling biodegradation rates. Aquifer sediments collected from a variety of locations across the site contain bacteria capable of aerobically mineralizing some of the principal aromatic compounds in the groundwater plume (benzene, naphthalene, and phenanthrene). Parallel mineralization assays incubated under aerobic and anaerobic conditions strongly suggest that O2 availability is a primary factor controlling the rate and extent of biodegradation. Data indicate that sorption may have also significantly affected biodegradation rates by limiting the bioavailability of the aromatic compounds. A mass transfer-limited numerical model was developed to explore the effect of sorption and bioavailability on biodegradation rates. In this model biodegradation rates are proportional to aqueous concentration, which is directly reduced by sorption. Both biotransformation and bacterial growth are described as being controlled by the rate of desorptive mass transfer. The influence of sorption on biodegradation is quantified by defining a Bioavailability Factor, Bf. A Thiele Modulus which indicates the ratio of characteristic times for sorption and biodegradation is helpful for determining the extent of mass transfer control during biodegradation of the aromatic compounds. This approach is preferred to equilibrium partitioning models, which may overestimate biodegradation rates by failing to consider the effect of rate-limited desorption on bioavailability.

Biodegradation of aromatic compounds under mixed oxygen/denitrifying conditions: a review

Bioremediation of aromatic hydrocarbons in groundwater and sediments is often limited by dissolved oxygen. Many aromatic hydrocarbons degrade very slowly or not at all under anaerobic conditions. Nitrate is a good alternative electron acceptor to oxygen, and denitrifying bacteria are commonly found in the subsurface and in association with contaminated aquifer materials. Providing both nitrate and microaerophilic levels of oxygen may result in oxidation of the stable benzene rings in aromatic contaminants and allow for the intermediates of this oxidation to degrade via denitrification. The effects of using mixed electron acceptors on biodegradation of subsurface contaminants is unclear. Below some critical oxygen threshold, aerobic biodegradation is inhibited, however high levels of oxygen inhibit denitrification. The mechanisms which regulate electron transfer to oxygen and nitrate are complex. This review: 1) describes the factors which may affect the utilization of oxygen and nitrate as dual electron acceptors during biodegradation; 2) summarizes the incidence of dual use of nitrate and oxygen (aerobic denitrification); and 3) presents evidence of the effectiveness of bioremediation under mixed oxygen/nitrate conditions.

Human papillomavirus infection of the uterine cervix of women without cytological signs of neoplasia

One hundred and six patients were studied whose cervical smears showed only non-specific inflammatory changes. Screening for genital pathogens yielded only a few positive cases. Histological examination of biopsy specimens taken by colposcopically directed tissue sampling showed cervical intraepithelial neoplasia in 13 of the women (12.3%). Deoxyribonucleic acid (DNA) hybridisation techniques were used to detect human papillomavirus, which was found in 24 patients (22.6%). In a second group of 104 patients with normal cervical cytology tissue biopsy samples were obtained and examined histologically but in no case was cervical intraepithelial neoplasia found. On DNA hybridisation, however, 12 patients (11.5%) were found to be positive for human papillomavirus. In this group finding human papillomavirus DNA was usually associated with a columnar ectopy. An association between human papillomavirus type 16 DNA and both cervical intraepithelial neoplasia and cervical cancer is well established. In this study it was type 16 which occurred most frequently in both groups.

Haematology, weight and condition of captive red grouse (Lagopus lagopus scoticus) infected with caecal threadworm (Trichostrongylus tenuis)

Red grouse infected with the caecal threadworm Trichostrongylus tenuis developed a mild anaemia. Haemoglobin and albumin levels in the blood fell but there were no significant changes in the number of red blood cells or their size. In infected birds the numbers of circulating eosinophils and heterophils increase, as did the concentration of alpha, beta and gamma globulin. Body weights did not change but muscle masses shrank. Birds that subsequently died had the lowest concentration of haemoglobin and packed cell volumes and the highest counts of eosinophils. The survivors were affected little by worms and their haematology showed small deviations from normal.