Baseline occurrence of organochlorine and organophosphate pesticides in water, sediment, and fish in the Miankaleh wetland, Iran.

Micropollutants such as pesticides and the prediction of water quality in aquatic environments have been known as a serious risk to the environment and human health. The pollution level of six pesticides-three organochlorines (OCPs: aldrin, dieldrin, and endrin) and three organophosphates (OPPs: diazinon, malathion, and azinphosmethyl)- in water, sediment, and fish samples was examined in the Miankaleh wetland, Iran. Water quality, including dissolved oxygen (DO), biological oxygen demand (BOD), chemical oxygen demand (COD), salinity, electrical conductivity (EC), turbidity, total dissolved solids (TDS), pH, temperature, and physicochemical properties of sediments, was analyzed.

Poikilothermia syndrome.

Poikilothermia syndrome is a rare cause of intrinsic thermoregulatory failure. Patients with this syndrome regulate body temperature poorly, if at all. Recently, a patient was referred to us who had clinical evidence of poikilothermia syndrome, as well as long-standing multiple sclerosis.

Paralysis only slightly reduces the febrile response to interleukin-2 during isoflurane anesthesia.

Background: Fever sometimes occurs during anesthesia. However, it is rare considering how often pyrogenic causes are likely to be present and how common fever is after surgery. This low incidence results in part from dose-dependent inhibition of fever by volatile anesthetics.

Meperidine and alfentanil do not reduce the gain or maximum intensity of shivering.

Background: Thermoregulatory shivering can be characterized by its threshold (triggering core temperature), gain (incremental intensity increase with further core temperature deviation), and maximum intensity. Meperidine (a combined mu- and kappa-agonist) treats shivering better than equianalgesic doses of pure mu-opioid agonists. Meperidine's special antishivering action is mediated, at least in part, by a disproportionate decrease in the shivering threshold.

Circadian changes in the sweating-to-vasoconstriction interthreshold range.

Thermoregulatory defenses are characterized by thresholds, the core temperatures triggering each response. Core body temperature is normally maintained within the interthreshold range, temperatures between the sweating and vasoconstriction thresholds that do not trigger autonomic defenses. This range usually spans only some 0.

Local radiant heating increases subcutaneous oxygen tension.

Background: We evaluated a novel bandage that incorporates a thermostatically controlled radiant heater. We first determined optimal bandage temperature, based on increases in subcutaneous oxygen tension, a measure correlating well with resistance to infection and wound strength. We then tested the hypothesis that prolonged radiant heating would increase collagen deposition in experimental thigh wounds.

Time-dependent changes in heart rate and pupil size during desflurane or sevoflurane anesthesia.

Unlabelled: To better characterize alterations in autonomic function associated with prolonged anesthesia, we tested the hypothesis that the time-dependent effects of sevoflurane and desflurane differ. We studied seven male volunteers, each anesthetized for 8 h with 1.25 minimum alveolar anesthetic concentration desflurane on one study day and with 8 h sevoflurane on another.

Alfentanil blocks reflex pupillary dilation in response to noxious stimulation but does not diminish the light reflex.

Background: Estimation of the mu-agonist opioid effect in anesthetized and paralyzed patients is often imprecise and can be obscured by concomitant administration of drugs that affect the sympathetic nervous system, such as beta-adrenergic blocking agents. As an alternative to hemodynamic measures of opioid effect, the authors tested the hypothesis that the pupillary light reflex or pupillary reflex dilation correlated with alfentanil concentrations during isoflurane anesthesia.

Methods: Six volunteers were anesthetized on 4 days with 0.

Dexmedetomidine does not alter the sweating threshold, but comparably and linearly decreases the vasoconstriction and shivering thresholds.

Background: Clonidine decreases the vasoconstriction and shivering thresholds. It thus seems likely that the alpha2 agonist dexmedetomidine will also impair control of body temperature. Accordingly, the authors evaluated the dose-dependent effects of dexmedetomidine on the sweating, vasoconstriction, and shivering thresholds.

Lidocaine does not depress reflex dilation of the pupil.

Background And Objectives: Pupillary dilation in response to dermatomal electrical stimulation is one method of determining sensory block level during combined epidural and general anesthesia. Use of this technique may, however, be confounded by systemic absorption of epidurally administered local anesthetics. Accordingly, the effects of intravenous lidocaine on the magnitude and duration of reflex pupillary dilation were evaluated.

Thermoregulatory vasodilation increases the venous partial pressure of oxygen.

Unlabelled: Thermoregulatory arteriovenous shunt vasoconstriction may facilitate deep-vein thrombosis by producing relative venous stasis and hypoxia. Accordingly, we evaluated the effect of vasomotion on leg blood flow and venous oxygen tension. We studied five male volunteers, each of whom was warmed enough to trigger vasodilation and then cooled sufficiently to provoke thermoregulatory vasoconstriction.

Sympathetic nervous system does not mediate reflex pupillary dilation during desflurane anesthesia.

Background: Pupil size is determined by an interaction between the sympathetic and parasympathetic divisions of the autonomic nervous system. Noxious stimulation dilates the pupil in both unanesthetized and anesthetized humans. In the absence of anesthesia, dilation is primarily mediated by the sympathetic nervous system.

Desflurane slightly increases the sweating threshold but produces marked, nonlinear decreases in the vasoconstriction and shivering thresholds.

Background: Shivering is rare during general anesthesia. This observation suggests that anesthetics profoundly impair shivering. However, the effects of surgical doses of volatile anesthetics on control of shivering have yet to be evaluated.