Evaluation of surgical tapes for wound closure

The performance of four wound closure tapes was evaluated by a series of standardized tests. The tapes examined in this study were a nonwoven microporous tape, a nonwoven microporous reinforced tape, a gauze tape, and a polyurethane tape. The performance of these tapes was assessed by measuring their breaking strength, degree of elongation under loading, adhesion to skin, air and water vapor transmission, and bacterial growth under the tape. On the basis of these in vitro and in vivo studies, the nonwoven microporous tape is recommended for skin closure. This tape has a nonwoven microporous structure with an adhesive that aggressively adheres to the underlying skin. It is strong enough to resist breakage during clinical use and elongates sufficiently to prevent blister formation. Its microporous structure permits rapid air transmission in vitro and results in an environment that is antithetical to bacterial growth.     

Excretion of cadmium and mercury in rat saliva

The excretion of cadmium and mercury in saliva was studied in urethane-anesthetized male rats given single intravenous injections of ¹⁰⁹CdCl₂ or ²⁰³HgCl₂ (0.1 or 1.0 mg divalent cation/kg). Pilocarpine (20 mg/kg, ip) was used to stimulate salivation. All doses produced a distinct and persistent increase in blood pressure (15–25 mm Hg), an increase in salivary flow rate and an increase (19–26%) in salivary gland weight. Metal levels in saliva (S) and submaxillary gland tissue (T), relative to blood (B), plasma (P), and filtrate (F) were determined. Cadmium and mercury were detected in S and T at both doses. The following relative order was apparent: $\text{S}\text{F}\text{>}\text{S}\text{P}\text{>-}\text{S}\text{B}$. $\text{S}\text{F}$ ratios were >1, suggesting a concentrating effect by the salivary gland. $\text{S}\text{B}$ and $\text{S}\text{P}$ ratios for mercury increased with increasing dose; $\text{S}\text{B}$ and $\text{S}\text{P}$ ratios for cadmium decreased with increasing dose. Similar dose-related effects were apparent in the $\text{T}\text{B}$ and $\text{T}\text{P}$ ratios.     

Evidence for appearance of “lysis independent” procoagulant activities in collagen or thrombin stimulated platelets

The availability of procoagulant activities in platelet suspensions lysed by sonication correlated directly with the degree of lysis (loss of LDH and ⁵¹Cr). Separate measurements of platelet factor 3 (PF3) and Factor V/Va activity revealed significant differences in appearance of these platelet activities in sonicated cell suspensions. Platelet factor 3 activity increased almost in parallel to the loss of ⁵¹Cr, whereas Factor V/Va activity became available at a significant slower rate. This might be explained by the localization of Factor V/Va activities inside the α-granules and therefore not immediately available on the surface of the partially lysed platelets.No increase in lactate dehydrogenase or ⁵¹Cr-loss was observed during 12 min incubation of platelet suspension with collagen or thrombin, whereas both PF3 and Factor V/Va activities increased. Thus, the high platelet factor 3 activity of 34% (lysed platelets 100%) measured in thrombin stimulated platelet suspensions probably represents “lysis-independent” activity.     

Anti-arrhythmic effects of lidocaine metabolites

Patients on lidocaine infusions for the control of arrhythmias accumulate significant concentrations of lidocaine metabolites. The potency of lidocaine in suppressing digitalis-induced arrhythmias in guinea pig atria was compared to that of two of the metabolites of lidocaine monoethyglycinexylidide (MEGX), and glycinexylidide (GX). The potency of MEGX relative to lidocaine was 0.833. GX was only $\text{1}\text{10}$ as potent. Thus, it would seem that MEGX may contribute to the total anti-arrhythmic effect of a lidocaine infusion.     

Inhalation bioassay of cigarette smoke in rats

Groups of 80 female rats were exposed to cigarette smoke from three types (code 13 = high tar, low nicotine; code 27 = low tar, medium nicotine; code 32 = high tar, high nicotine) of cigarettes in Maddox-ORNL smoking machines, eight cigarettes per day, 7 days per week, for up to 24 months. An additional group received sham exposures and a fifth group served as untreated controls. The sham-exposed animals had significantly lower body weights than the untreated controls. The smoke-exposed animals had significantly lower weights than the sham-exposed controls; the weights were lower for the code 27 and code 32 animals than for the code 13 animals during the second year of exposure. The survival of the code 13 animals was similar to that for the sham-exposed and untreated control group; survival times of the code 27 and code 32 animals were shorter. Body weight and survival reflected the high- and low-nicotine dose groups indicated by in vivo dosimetry measurements. Smoke-induced histopathologic lesions consisted primarily of pulmonary smoke granulomas; the smoke granulomas were less severe in the code 27 exposure group than in the groups exposed to smoke from code 13 or code 32 cigarettes. Additional changes included pulmonary alveolar epithelial hyperplasia, and squamous metaplasia and basal cell hyperplasia of laryngeal and tracheal epithelium. One primary epidermoid carcinoma was found in the lung of a code 27 rat. The rats tolerated the chronic exposures relatively well and certain of the smoke-induced lesions allowed differentiation between the different types of cigarettes.     

The management of anticoagulation during noncardiac operations in patients with prosthetic heart valves

Based on previous thromboembolic complications associated with the interruption of anticoagulation during subsequent noncardiac operations in patients with nonbilogical mitral prostheses, a protocol was developed for this high risk group. We report the successful management of 26 such operations in which anticoagulation was interrupted for 12 hours and then rapidly restored by means of heparin in the postoperative period. Since an earlier study suggested no adverse effect from the interruption of chronic anticoagulants for three to five days among patients with isolated aortic valve prostheses, simple interruption was again employed during 16 subsequent noncardiac operative procedures in this group with no complications. There were three episodes of hemorrhage observed in patients receiving therapeutic doses of heparin postoperatively, but only one required blood replacement.     

Mental status examination: Myth or method

Our clinical experience, as well as literature review, indicate that the MSE may be more myth than method in contemporary psychiatry. Given the current common language available through DSM (III) and the APA Glossary, the MSE may well have enhanced potential as a practical clinical tool because it can be transferable, affordable, portable, and not machine dependent. Having intervened, as noted above, we intend to follow-up via clinical records, interview and questionnaire to determine whether more consistent notation by trainees is present and whether trainees have a shared concept as to form and clinical utility of the MSE.