Inhibitory effects of amitriptyline on the stimulation-induced Ca2+ increase in parotid acini

The present study demonstrates the effects of the antidepressant, amitriptyline, and the acetylcholine antagonist, atropine, on the stimulation-induced rise in cytosolic, free Ca2+ (Cai2+). The changes in Cai2+ of collagenase-isolated rat parotid acini were measured by means of the Ca2(+)-sensitive dye, fura-2. It was found that stimulation by carbachol resulted in a maximal increase of 582 +/- 34 nM (mean +/- S.E.) in Cai2+ with a ks of 5.8 +/- 1.3 microM. Adrenaline caused a rise of 380 +/- 22 nM in Cai2+ with a ks of 0.5 +/- 0.2 microM. Amitriptyline and atropine were found to inhibit the carbachol-induced rise in Cai2+ with dissociation constants (kI) of 105 and 1.25 nM, respectively, in the absence of agonist. The adrenergic-induced rise in Cai2+ was inhibited by amitriptyline with a kI of 45 nM. Amitriptyline was found to inhibit both receptor classes by a competitive or mixed type of inhibition. Similarly, atropine exerted the same type of inhibition on the acetylcholine receptor. Amitriptyline and atropine were found to be mutually exclusive for competing for substrate binding on the receptor. These findings are consistent with a common binding site for amitriptyline and atropine on the acetylcholine receptor, possibly in close proximity with, but different from the substrate binding site. The stimulation-induced cell shrinkage evoked by the loss of electrolytes and water from the acini was measured by a 90 degree light scattering signal. It was found that this method makes possible the detection of autonomic side-effects of antidepressants on acini suspended in protein-containing media.     

Recycling suitability of wash waters from mosquito abatement vehicles and equipment into spray diluent

In response to changing laws as well as increased concern over environmental pollution, there is a current need to examine the best means of disposal of wash water generated by mosquito abatement operations. A study of wash waters from 6 central California mosquito abatement districts shows that herbicide levels were low enough so as not to preclude the use of these waters for recycling back into insecticide spray diluent. In one case, oil levels were high and an oil/water separation is probably necessary to prevent gum formation and clogging of spray equipment. Recycling of wash waters appears to be a feasible solution to the disposal problem once water contaminant levels are defined.     

Clinicopathologic correlation of pigmented epiretinal membranes

We performed clinicopathologic correlation on ten surgically removed pigmented epiretinal membranes causing macular pucker. All cases occurred in eyes with existing retinal holes or tears, including eight cases of macular pucker after previous retinal detachment. These cases probably represented a limited form of proliferative vitreoretinopathy. All membranes contained pigment epithelial cells with polarity, basement membrane, and melanosomes. Cytoplasmic melanin granules accounted for the clinical feature of pigmentation in these eyes.     

Infantile glaucoma in Down's syndrome (trisomy 21)

We examined five patients with Down's syndrome and bilateral infantile glaucoma. In the first few months of life four patients had large cloudy corneas, breaks in Descemet's membrane, increased intraocular pressure, photophobia, and tearing. In one patient the diagnosis was delayed until 3 1/2 years of age because of concomitant nasolacrimal duct obstruction. Two patients developed cataracts and retinal detachment and have undergone multiple surgical procedures. The clinical course in these two older patients suggests that coexistence of congenital glaucoma, severe myopia, and cataracts in patients with trisomy 21 strongly predisposes for the development of retinal detachment and poor visual outcome.     

Evaluation of two hot water washer disinfectors for medical instruments

Two models of hot water washer disinfectors (Decomat 128 and Hospital A, Euroclean Canada Inc; Ontario, Canada) were evaluated by two methods for their efficacy in disinfecting anesthesia equipment. In the first method, three different microbial suspensions were each sealed into 30 capillary tubes. In the second method, corrugated anesthesia tubes were rinsed with suspensions of each of two bacterial strains. The tubes then underwent a standard cycle in the hot water washer disinfectors and were subsequently tested for growth of microorganisms. All experiments were repeated three times, and the temperature was registered in all cases. In the capillary test, growth was rarely detected (13/540 tubes) and the inactivation factor for both apparatus was greater than 5 log10. In the rinse test, no growth was detected. The mean temperature for 15 disinfection cycles was 84.2 +/- 0.8 degrees C for Decomat 128 and 88.9 +/- 0.5 degrees C for Hospital A. However, for Decomat 128 we observed a variation of 3 degrees C from one disinfection cycle to another and a progressive reduction of 2.2 degrees C over a series of five consecutive complete cycles. Both methods gave reproducible results. Under our experimental conditions, both hot water washer disinfectors proved to be efficacious for the disinfection of reusable anesthesia equipment.