Comparing the performance of three methods to assess DOM dynamics within two distinct glacierized watersheds of the tropical Andes.

Dissolved organic matter (DOM) is recognized as a good indicator of water quality as its concentration is influenced by land use, rainwater, windborne material and anthropogenic activities. Recent technological advances make it possible to characterize fluorescent dissolved organic matter (FDOM), the fraction of DOM that fluoresces. Among these advances, portable fluorometers and benchtop fluorescence excitation and emission spectroscopy coupled with a parallel factor analysis (EEM-PARAFAC) have shown to be reliable. Despite their rising popularity, there is still a need to evaluate the extent to which these techniques can assess DOM dynamics at the watershed scale. We compare the performance of in-situ measurements of FDOM with laboratory measurements of fluorescence spectroscopy within the context of two distinct glacierized watersheds in Peru. Glacierized watersheds represent unique testing environments with contrasting DOM conditions, flowing from pristine, vegetation-free headwaters through locations with obvious anthropogenic influences. We used an in-situ fluorometer and a portable multimeter to take 38 measurements of FDOM, pH and turbidity throughout the two catchments. Additionally, samples were analyzed in the laboratory using the EEM-PARAFAC method. Results were compared to dissolved organic carbon (DOC) measurements using standard high-temperature catalytic oxidation. Our results show that the three techniques together were able to capture the DOM dynamics for both studied watersheds. Taken individually, all three methods allowed detection of the watershed DOM main points of sources but in a more limited way. Due to the narrow bandwidth of the portable fluorometer used in the study, FDOM measurements were almost non-detectable to protein-like substances. Indeed, the more demanding EEM-PARAFAC was able to both differentiate between potential sources of DOM and provide an estimate of relative concentrations of different organic components. Finally, similar to FDOM but to a lesser extent, the DOC measurements showed some limits where protein-like substances make up most of the DOM composition.

Case of the month: "bugs are eating my soul"--sternal abscess, osteomyelitis, and mediastinitis complicating a closed sternal fracture.

Wound complications of closed sternal fracture are rare, but may have serious consequences if not effectively managed. We report a case of a patient who presented to the emergency department with a sternal abscess, osteomyelitis, and mediastinitis complicating a closed sternal fracture. It is hypothesised that in our patient bacteraemia post intravenous drug use resulted in seeding of the haematoma with Staphylococcus aureus. Early diagnosis and a multidisciplinary team effort were important in ensuring a favourable outcome.

Improving the delivery of analgesia to children in pain.

OBJECTIVES: To improve the time taken for children arriving to the accident and emergency (A&E) department in pain to receive analgesia. Delivery within 30 minutes of triage was taken as an achievable goal. METHODS: 262 children who had received analgesia in the "minor injuries" area of West Middlesex University Hospital A&E department were studied over a four month period. Current practice was indicated over the first two months by retrospectively looking at data from 129 children's A&E cards. A Paediatric Pain Protocol was then introduced and another 133 children's cards studied to see if this had made an improvement. The protocol for those children aged over 4 years differed to that for children aged 4 years and under. RESULTS: For children aged 4 years and over, the introduction of the protocol significantly increased the number that received analgesia within 30 minutes of triage: 55.3% (n=54) post-protocol versus 34.0% (n=33) pre-protocol (p=0.003). However, for children aged 4 years and under there was no change in the proportion that received analgesia within 30 minutes of triage: 56.7% (n=17) postprotocol versus 59.4% (n=19) pre-protocol (p=0.829). CONCLUSIONS: The introduction of a simple Paediatric Pain Protocol has improved the time taken to deliver analgesia to children arriving in this A&E department.

Meningeal myeloma in the absence of systemic disease, and as the initial feature of disease progression.

We describe a 60-year-old man with stage IIA myeloma, who despite achieving a systemic remission after C-VAMP, progressed with isolated meningeal myeloma. Meningeal involvement in myeloma is a rare complication with a poor prognosis.

Selected cases of poor outcome following a minor brain trauma: comparing neuropsychological and positron emission tomography assessment.

Neuropsychological residua are common particularly in the early stages following a minor traumatic brain injury (TBI), however, a minority of individuals complain of persistent deficits following months or years post-accident. Nine such cases are presented with little or no evidence of brain damage demonstrated according to non-functional neuroimaging (for example CT, MRI), yet their neuropsychological examinations were positive. Since the introduction of positron emission tomography (PET), which captures a functional approach, the question arose as to what extent the two techniques (i.e. PET and neuropsychological examination) are interrelated. All nine minor TBI cases revealed a corroboration between the positive neuropsychological findings confirmed on the PET. The PET procedure documented neuropathology which frequently was pronounced in the frontal and anteriotemporo-frontal regions. Moreover, no significant differences were evident between those five cases with reported loss of consciousness vs. those four cases without.

Seasonal study of methane oxidation in lake washington.

The distribution of methane and methane-oxidizing bacteria in the water column of Lake Washington was determined monthly for 1 year. The methane profiles were relatively constant, with little stratification and low concentrations (0.05 to 0.5 muM). The number of methane-oxidizing bacteria detected by a filter-plating method was routinely <1/ml throughout the water column, and no incorporation or oxidation of methane was detected by radioisotopic labeling, even after methane was added. However, samples taken from the sediment-water interface contained as much as 3 muM methane and 50 CFU of methane-oxidizing bacteria per ml and showed significant rates of methane oxidation and incorporation. To define the region of maximum activity more precisely, vertical profiles of the sediment were examined. The concentration of methane increased with depth to a maximum of 150 to 325 muM at 2.5 cm, and significant rates of methane oxidation were found within the top 2.5 cm. The apparent K(m)s for methane and oxygen were determined for samples from the top 1.0 cm of the sediment and found to be ca. 10 and 20 muM, respectively. Projected values for methane oxidation rates suggested that maximum methane oxidation occurred in the top 0.5 cm of the sediment.

Improved hemodialysis access in children.

Vascular access for chronic hemodialysis in children is difficult because of problems that include obtaining vessels of sufficient size, the limited life-span of external shunts, and the multiple painful punctures associated with internal fistulae. Twenty-five expanded polytetraflouroethylene (PTFE) grafts of 6-mm diameter were inserted for dialysis access over a 2-yr period in 23 children. Grafts were placed either in the upper arm or thigh. Each patient was successfully dialyzed from 60 to 370 times. Longterm patency of the PTFE grafts was 88%, with a complication rate of 36%, mostly minor. The same ease of insertion and high flow characteristics were noted in a series of 22 bovine carotid heterograft (BCH) fistulae inserted in the two years immediately preceeding this study. However, the patency rate was only 36% and the complication rate was 69%, mostly major. We consider the PTFE graft fistula to be the preferred method for long-term hemodialysis access in children.

Common duct stones in infancy.

The term "bile ascites" is used when the bilirubin content of the ascitic fluid is higher than it is in the serum. Two cases of newborn infants with bile ascites associated with common duct stones are reported. Review of the literature reveals 11 additional cases of common duct stones that presented as bile ascites. The surgical treatment of bile ascites and common duct stones is described. In spite of the severity of the problem, the outcome is successful in most cases (83.3% survival in this review).

Surgical repair of the injured spleen.

Fatal sepsis has been reported with increasing frequency following splenectomy for trauma. Efforts to save the spleen were made in 17 children with blunt abdominal trauma. Two patients required splenectomy, but 15 were managed successfully by splenic repair. No patient required reoperation, and there were no complications. Follow-up scans were remarkably normal. It is concluded that splenic lacerations are usually amenable to suture repair, and splenorrhaphy, not splenectomy, is the treatment of choice for splenic injury.