The development of whole cell biosensors for on-line screening of herbicide pollution of surface waters

The use of mediator assisted amperometric whole-cell biosensors, monitoring microbial photosynthetic electron transfer, to screen for herbicides in intake protection by the water industry is described. Cells harvested from axenic cultures are loaded onto bacteriological filters and held against a working carbon electrode polarised against the silver chloride reference. Redox mediators are reduced by the microorganisms and then reoxidised at the working electrode resulting in a flow of current. For on-line applications the sensors are controlled by a programmable electrochemical analyser (Artek) and housed in specially designed perspex flow cells which incorporate light emitting diodes (LEDs) for photosynthetic stimulation. A range of cyanobacteria and algae have been tested, but biosensors incorporating unicellular cyanobacteria have proven the most successful. Results obtained using the cyanobacterium Synechococcus show detection levels of less than 200 ppb with response times of less than ten minutes for selected herbicides. Sensor stability in the absence of pollutant poisoning has been found to be greatly influenced by the choice of mediator. Membrane penetrating mediators such as -benzoquinone reduce sensor life to about 24 hours, while a sensor life of up to six days has been achieved with ferricyanide.     

Successful replantation of amputated nose and auricle

Amputations of the nose and of the auricle present difficult management problems. Application of simple reattachment techniques, followed by aggressive medical therapy which consists of cooling, anticoagulation, antibiotic coverage, and multiple stab incisions in the amputated tissues, have resulted in the successful replantation of major portions of an amputated nose and an amputated auricle with satisfactory cosmetic results.     

The prevalence and expression of diabetes in a sample of optometric patients

The clinical characteristics of 100 consecutively presenting diabetic patients of an optometrist were investigated. This sample was drawn from 3798 patient first visits and represented 2.6% of the practice population sample. Diabetic retinopathy was present in 26% of the diabetic patients; this prevalence is similar to that found in diabetics examined in community based surveys. The ocular complications of diabetics observed in this study appeared to be similar to those of diabetics in the general community. The mean random blood glucose levels of the diabetics having retinopathy was not significantly different from those not having retinopathy. A first degree family history of diabetes was admitted by 46% of the diabetic subjects and was the most common associated clinical feature surveyed; a control group of non-diabetic subjects had a first degree family history of diabetes in 10% of cases. In seven patients, the diabetes was diagnosed as a result of signs detected at the optometric examination; these signs are listed. No newly diagnosed diabetic had diabetic retinopathy as a presenting sign. Ocular and systemic signs, other than diabetic retinopathy, were sought and a high prevalence of cardiovascular disease was detected in these diabetic patients. The vision of the diabetic patients was compared to that of 100 randomly selected age and sex matched controls; there was no significant difference in the visual acuity of the two groups. The implications of this finding are discussed. Guidelines for the detection and management of diabetic patients of optometrists are suggested.     

A review of the effects of expansion of the nasal base on nasal airflow and resistance.

PURPOSE: The purpose of this article is to inform the reader of the current literature regarding nasal airflow resistance. The anatomy and physiology of nasal airflow resistance will be examined and the known effects of widening of the nasal airway upon airflow will be described. MATERIALS AND METHODS: This article is a review of the current literature regarding nasal airflow and resistance and the effects of widening of the nasal base. No patient data were collected. RESULTS: The literature shows that nasal airflow resistance can be changed by surgical manipulation and by rapid palatal expansion, but that the effects on airflow resistance and future growth and development are unpredictable. CONCLUSION: Patients with a maxilla that is constricted in the transverse dimension and nasal airflow problems may benefit from expansion of the nasal base. The resultant effects upon nasal airflow resistance and subsequent growth and development are unpredictable and therefore airflow issues alone may not be a primary reason to increase the transverse dimension of the nasal base.     

Firearms in the home and child safety

One hundred fifty families who were seen in the pediatric outpatient clinics at The University of Texas Medical Branch, Galveston, were surveyed to learn about firearm possession in the home and its hazards to children. Thirty-eight percent of these families kept at least one gun in their home. Fifty-five percent of this group reported that the gun was loaded at all times, and 10% reported that the gun was kept loaded, unlocked, and within the reach of a child. We identified demographic characteristics of at-risk families and considered national statistics for gun safety. It was concluded that household firearms pose a significant risk to children and that intervention by physicians could help reduce this public health problem.     

Synthesis of 14C‐labeled piperidines and application to synthesis of [14C]SCH 351125, a CCR5 receptor antagonist

1‐Benzyl‐4‐hydroxy[2‐¹⁴C]piperidine, a useful intermediate in labeled compound synthesis, was prepared from [¹⁴C]formaldehyde in high yield. The distribution pattern of ¹⁴C in the product is consistent with a mechanism involving reversible iminium ion formation and rapid equilibration of the iminium ion through a cationic aza‐Cope rearrangement. These steps precede the rate‐determining intramolecular cyclization step. SCH 351125 is a potent, selective CCR5 receptor antagonist with potential as a treatment for HIV infection. [¹⁴C]SCH 351125, required for metabolism studies, was prepared from 1‐benzyl‐4‐hydroxy[2‐¹⁴C]piperidine in six steps. [¹⁴C]SCH 351125 is a mixture of four atropisomers. Preparation of [¹⁴C]SCH 351125 besylate salt of the desired atropisomer pair is also described. Copyright © 2007 John Wiley & Sons, Ltd.     

Caring for patients with traumatic injuries of the thoracic aorta.

Trauma is a major cause of mortality and morbidity in the United States, with blunt traumatic injuries of the thoracic aorta continuing to occur despite the increased use of seatbelts and airbags. Emerging from crash analysis are effective interventions and provides increased awareness of the occult nature of these types of injuries. This article describes those interventions that healthcare providers must embed throughout the continuum of care for patients experiencing thoracic aortic injuries. Outcomes will be dependent upon the healthcare provider's knowledge of the physics of the event and the urgency of the diagnosis, as well as the ability to assess and manage all the variables involved. Current procedural issues are delineated and case studies are used to illustrate the processes of care needed by these patients.