Intensive Monitoring Period Research Articles

Mesalazine-associated interstitial nephritis

When used for oral treatment of inflammatory bowel disease, Asacol (a coated form of mesalazine = 5-aminosalicylic acid) can cause interstitial nephritis. The spectrum of severity, frequency of occurrence and the best renal function test to detect this complication are not known. The value of immunosuppression in addition to drug withdrawal is similarly undetermined. Four cases of interstitial nephritis which occurred in association with oral Asacol treatment are presented and a further 12 cases who received similar treatment are reviewed. Clinical trials published previously were scrutinized to assess the frequency of impaired renal function. The available evidence suggests that renal impairment of any severity may occur in up to 1 in 100 patients, but that clinically significant interstitial nephritis occurs in less than 1 in 500 patients. This is most reliably detected by an elevated serum creatinine concentration. If the diagnosis of nephrotoxicity is delayed until 18 months after commencement of medication, restoration of renal function, which is seen on withdrawal of medication alone up to 10 months, does not occur and there is no evidence to date to indicate that addition of immunosuppression confers any significant advantage at this later stage. It is suggested that serum creatinine concentration should be measured each month for the first 3 months of treatment, 3-monthly for the remainder of the first year and annually thereafter. The use of concurrent immunosuppressive therapy may necessitate extension to the period of intensive monitoring. Any elevation of serum creatinine which cannot be related to a relapse of inflammatory bowel disease should prompt immediate withdrawal of Asacol and related medications and substitution of alternative therapy. Neither the lack of urinary abnormalities on routine testing nor the absence of clinical or laboratory features of drug allergy can be relied upon to rule out interstitial nephritis during oral therapy with these drugs.

Government policy influences on rangeland conditions in the United States: A case example

Since the early 1970s the Bureau of Land Management (BLM) and the Forest Service have emphasized the monitoring approach in managing their rangelands. After a 5-year period of intensive monitoring, stocking rate and other management actions are typically adjusted, depending on whether a definite downward or upward trend in range condition is observed. Examining the Afton Allotment on BLM land in southcentral New Mexico, we demonstrate serious flaws in the monitoring approach and other BLM grazing policies. Monitoring reflects past management but does not consider the future. Perverse incentives for permittees to maximize permit value rather than sustain the forage base still remain in place. The "Range Reform '94" proposals by the U.S. Department of the Interior do not address these incentives and other flaws in public land policy. We would reform federal grazing land policy by coupling grazing fees to grazing intensity. Ranchers choosing conservative sustainable grazing intensities would pay low fees, whereas those choosing heavy grazing intensities would be charged higher rates. We would also implement other reforms: making livestock grazing permits transferable to other uses, discontinuing subsidies, eliminating restrictions on nonuse, offering incentives for public land investment, and establishing a biodiversity fund.

The Dielmo project: a longitudinal study of natural malaria infection and the mechanisms of protective immunity in a community living in a holoendemic area of Senegal.

The Dielmo project, initiated in 1990, consisted of long-term investigations on host-parasite relationships and the mechanisms of protective immunity in the 247 residents of a Senegalese village in which malaria is holoendemic. Anopheles gambiae s.l. and An. funestus constituted more than 98% of 11,685 anophelines collected and were present all year round. Inoculation rates of Plasmodium falciparum, P. malariae, and P. ovale averaged respectively 0.51, 0.10, and 0.04 infective bites per person per night. During a four-month period of intensive parasitologic and clinical monitoring, Plasmodium falciparum, P. malariae, and P. ovale were observed in 72.0%, 21.1% and 6.0%, respectively, of the 8,539 thick smears examined. Individual longitudinal data revealed that 98.6% of the villagers harbored trophozoites of P. falciparum at least once during the period of the study. Infections by P. malariae and P. ovale were both observed in individuals of all age groups and their cumulative prevalences reached 50.5% and 40.3%, respectively. Malaria was responsible for 162 (60.9%) of 266 febrile episodes; 159 of these attacks were due to P. falciparum, three to P. ovale, and none to P. malariae. The incidence of malaria attacks was 40 times higher in children 0-4 years of age than in adults more than 40 years old. Our findings suggest that sterile immunity and clinical protection are never fully achieved in humans continuously exposed since birth to intense transmission.

Mathematical modeling of the concentrations of volatile organic compounds: model performance using a lumped chemical mechanism

An Eulerian photochemical model is used to predict the transport and reactions of organic gas emissions to the atmosphere. The model is applied to the Los Angeles area for the August 27-29, 1987, intensive monitoring period of the Southern California Air Quality Study (SCAQS), and predictions for each of the lumped organic species in the model are evaluated using speciated organic gas concentration measurements made at nine sites. Model calculations using the official State of California emission inventory accurately predicted the observed concentrations of ethene, monoalkylbenzenes, and formaldehyde, and underpredicted the concentrations of other organic species. When the on-road vehicle hot exhaust emissions of organic gases was scaled up to approximate the actual emission rates measured in a local roadway tunnel and revisions were made to the chemical composition profiles for the organic gas emissions, model performance for both ozone and most lumped organic classes improved. 42 refs., 6 figs., 6 tabs.

Photochemical modeling of the Southern California air quality study

The Southern California Air Quality Study (SCAQS) provides detailed experimental observations that can be used to explore the causes of the Los Angeles smog problem. In the present study, the CIT photochemical airshed model is updated and then applied to the August 27-29, 1987, SCAQS intensive monitoring period. Using measured meteorological parameters, measured initial and boundary conditions, and the official emission inventory prepared by the government, ozone concentrations are underpredicted by 23% on average. Recent field experiments suggest that emissions of organic gases and carbon monoxide are understated in the official emission inventory. When the organic gas emissions from on-road vehicle engine exhaust are increased as suggested by emission rate measurements made in a Los Angeles area roadway tunnel during SCAQS, ozone predictions match the observed concentrations more closely (the mean normalized bias in ozone predictions for this case is +1%). Reactive hydrocarbon concentrations are underpredicted by 35% in the base case calculation, but are underpredicted by only 12% in the increased emission case. Results of this study thus support prior estimates that the organic gas emissions in Los Angeles have been understated in recent years.

The neocortico to mesio-basal limbic propagation of focal epileptic activity during the spike-wave complex

In order to localize epileptogenic electrophysiological sources, a multichannel MEG system was used in 3 patients with partial epilepsy during presurgical evaluation. MEG and EEG (including scalp, sphenoidal and intracranial foramen ovale electrodes) were recorded simultaneously during a period of intensive video-EEG monitoring in order to observe single spontaneous spikes. In addition to MRI, SPECT and PET investigations were performed. Electrical activity subsequent to the activity of the epileptic focus could be localized by the MEG after noise reduction using a temporal correlation technique. Simultaneous registration of the magnetic field and the electrical field showed that the source of the primary focal epileptic activity (first period during the total spike wave complex where a dipolar magnetic field pattern is found) is localized in neocortical lateral regions, whereas another focal epileptic activity in a later phase of propagation occurs in temporal mesial regions. In 1 patient (case 1) the primary focal epileptic activity was localized in the surrounding neocortical tissue of an angioma and the middle and inferior temporal gyrus. The second phase of propagation is localized in temporo-basal-mesial regions, including para- and hippocampal structures. The latest center of activity occurred in posterior parts of the gyrus cinguli. In 2 other patients, the primary focal epileptogenic activity was localized at the insula and also spread into temporal basal mesial regions. A multi-modal approach to research of focal epilepsy, combining metabolic, electrical potential, magnetoencephalographic and morphological data, recorded by non-invasive techniques, offers new perspectives for the detection of involved brain regions. The 3-D and time-resolved localization of focal epileptic activity, correlated with the individual anatomy of the human brain, may improve the determination of neuronal populations involved in the individual epileptogenic process, especially in the interaction between temporal or extratemporal neocortex and limbic system.

Subtropical Atlantic Climate Studies: Introduction

This report is an introduction to the accompanying collection of reports that present the results of a 2-year period of intensive monitoring of the Florida Current. Both direct observing systems (ship-deployed current profilers and moored current meters) and indirect observing systems (coastal tide gauge stations, bottom pressure gauge arrays, a submarine cable, acoustic arrays, and radar installations) were used to measure temperature and volume transport.

Mesoscale analysis of ozone measurements in the Boston environs

The mesoscale analysis of ozone concentrations measured at ground level and aloft in the Boston metropolitan area has provided some insight into the origin and fate of urban ozone. A period of intensive airborne ambient air monitoring, conducted by the U.S. Environmental Protection Agency's Environmental Monitoring and Support Laboratory-Las Vegas long-range air-monitoring aircraft from August 9 through August 14, 1975, shows areas of semipersistent high and low ozone concentrations. In addition, data presented identify an urban ozone plume at extended distances downwind of Boston on several days within this sampling period. The importance of the daily synoptic meteorological situation upon the observed ozone distribution is emphasized. On August 9, ozone concentrations ranging as high as 103 ppb were measured aloft 35 km downwind of Boston. On this same day, immediately upwind of Boston, a surface ozone ridge was evident. Data collected on August 10–12 show that with persistent wind directions aloft an urban plume is discernible at distances of 50–100 km downwind. Ozone values as high as 148 ppb were measured within the urban plume; in fact, ozone concentrations exceeded 80 ppb as far as 200 km over the ocean, downwind of Boston, on August 12. On August 11 and 13 the local weather, situation apparently caused a sea breeze related surface ozone ridge pattern to recirculate high ozone levels over the Boston area late in the evening. August 14, a non-sea breeze day, featured a cold front passage through the Boston area. The ozone distribution pattern at the surface differed from surface patterns for other days studied. The ozone distribution pattern aloft was also less complicated than patterns aloft on other days studied.