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In order to estimate how long a medication can remain prepared before the integrity or concentration of the drug is compromised, we assessed the sterility and potency of medications commonly used in our obstetric anesthesia practice. Our goal was to evaluate the following drugs over a 30-day period: epinephrine, atropine, lidocaine, succinylcholine, and ephedrine. The medications were prepared by various medical staff, drawn into sterile plastic syringes and left at room temperature unprotected from light for the duration of the study. The syringes were collected daily, stored and randomly sampled after 7, 14, 21 and 30 days by research personnel. Potency and sterility of atropine, ephedrine and lidocaine were maintained over the study period. Succinylcholine and epinephrine could not be assayed but the solutions remained sterile for 30 and 14 days respectively. Data were incomplete for epinephrine. These findings suggest that some drugs that are commonly used in obstetric anesthesia are stable for long periods of time. Modification of current standards of practice could result in a significant reduction in drug waste and therefore cost.

Probiotic bacteria can protect immunodeficient mice from orogastric candidiasis but cause some pathology of their own. Severely immunodeficient patients may be at risk if fed viable probiotics, so this study evaluated the probiotic potential of nonviable probiotic bacteria to protect immunodeficient mice from Candida albicans infections. Heat-killed probiotic bacteria were fed to gnotobiotic bg/bg-nu/nu and bg/bg-nu/+ mice to ascertain if they could protect the mice from mucosal and systemic candidiasis. Both heat-killed Lactobacillus acidophilus (HKLA) and heat-killed Lactobacillus casei (HKLC), in comparison to control mice not fed the probiotic bacteria but challenged (oral) with C. albicans, suppressed the severity of orogastric candidiasis in bg/bg-nu/nu mice at 2 weeks after colonization with C. albicans, inhibited disseminated candidiasis in C. albicans-colonized bg/bg-nu/+ mice at 4 weeks after colonization, and suppressed the number of viable C. albicans in the alimentary tract. HKLA, but not HKLC, treatment inhibited disseminated candidiasis in bg/bg-nu/nu mice at 2 weeks after oral challenge and enhanced the proliferative responses of splenocytes from C. albicans-colonized bg/bg-nu/+ mice to C. albicans antigens. Neither HKLA nor HKLC were able to prolong the survival of gnotobiotic bg/bg-nu/nu mice after oral challenge with C. albicans. These results demonstrate that heat-killed lactobacilli can induce some (limited) protection (probiotic effect) against candidiasis in mice.

The presence and clinical significance of bacteria in the arterial wall, periarterial adipose tissue, and blood samples acquired during elective vascular operations were assessed in this study. Specimens were obtained from a random series of 84 patients (56 men, 28 women) undergoing 75 primary and 9 secondary arterial reconstructions. Operations performed most frequently included abdominal aortic aneurysmectomy (42), aortofemoral bypass reconstruction (15), and lower extremity bypass surgery for occlusive disease (7). Perioperative antibiotics were administered to all but one patient. A sample of artery, adjacent adipose tissue, and blood were obtained for microbial analysis during the vascular anastomosis or arteriotomy. This yielded a total of 152 artery, 139 adipose tissue, and 129 blood samples for study. Each specimen was divided and placed in blood agar plates, thioglycolate broth, and brain-heart infusion broth. Tissues yielding growth of the same organism(s) in two or more different media were considered positive for the presence of bacteria. Bacteria were present in at least one of the three tissues studied in 32/84 patients (38%). The frequency of positive cultures in primary (29/75, 39%) and secondary procedures (3/9, 33%) were similar. One positive culture site occurred in 26/32 (81%) patients, two positive culture sites existed in 5/32 (16%) patients, and three positive sites were found in 1/22 (3%) patients. Eighteen individual artery (18/152, 12%) and 19 adipose tissue samples (19/139, 14%) harbored bacteria, whereas only two blood cultures were positive (2/129, 2%). Organisms identified included coagulase-negative staphylococci (71%), gamma-streptococci (7%), diphtheroids (7%), Micrococcus (5%), alpha-streptococci (5%), Staphylococcus aureus (2%), and Pseudomonas picketti (2%).(ABSTRACT TRUNCATED AT 250 WORDS)

Freshly sacrificed hairless mice were burned dorsally by direct contact with 60 degrees C water for periods ranging from 15 seconds to 8 min. Wounds ranging in degree from superficial epidermis damage to injury penetrating well into subcutaneous musculature were inflicted. Burned skin sections and reference abdominal skin sections were excised, placed in diffusion cells and investigated with regards to their permeabilities to water, methanol, ethanol, n-butanol and n-octanol. The data were couched in terms of ratios of permeability coefficients of burned skin to normal skin (scalding coefficients) for the same animal. Scalding increased permeability of skin to all compounds studied but the effects leveled out by 60 seconds. Protracted scalding was without great effect despite progressively increased depth of damage to the tissue as noted in histological sections. The degree of lost barrier competency attributable to 60 degrees C scalding was not marked for any compound but was definitely different for different alkanols. An approximately 3-fold permeability increase was noted with n-butanol, the most affected compound. The data demonstrate that near instantaneous alterations in permeability of skin accompany scalding, that decreased barrier competency does not correlate with the severity of a burn as measured in depth of the burn, and that thermal alteration of permeabilities is dependent on the physicochemical characteristics of the permeants.

The safe antiseptic use of phenol over the burn-traumatized surface depends on knowledge of how the systemic accumulation of phenol is affected by burn processes. To gain insight into the underlying permeation phenomenon, the diffusion of phenol and a reference cosolute, methanol, through both scalded and branded dorsal skin sections of the hairless mouse was studied as a function of burn temperature using in vitro diffusion cells. Temperatures up to 100 and 150 degrees were used for scalding and branding, respectively, using a 60-sec; exposure time. Permeability coefficients of the traumatized skins were assessed at 37 degrees and compared with control values. Coefficients of both permeating species were not increased significantly by burn temperatures up to 70 degrees applied either by scalding or branding, however, at higher temperatures exaggerated increases in permeation rates were noted. A limiting increase of approximately 7 times the control value was noted for phenol irrespective of the burn method. Permeability of methanol was altered even more dramatically and at 100 degrees by scalding and 150 degrees by branding was over 50 times the control rate. At 80 and 100 degrees for methanol and at 80 degrees for phenol, scalding produced larger increases in the permeability coefficients than branding. Since contact for 1 min at 60 degrees is capable of producing a full-thickness burn injury, it is clear that eschar permeability to phenol immediately postburn is not related to the clinical degree of burning, but is a function of the thermal intensity (hotness) of the burn stimulus. Full-thickness wounds can be expected to have highly variable rates of systemic absorption as a direct consequence of the wide-ranging permeability possible for such burns, with the risks of topical application varying accordingly.

To assess how the permeability of phenol is altered by thermal injury, it was first necessary to have baselines of comparison on normal skin. Using in vitro diffusion cells and the skin of the hairless mouse, [14C]phenol was applied to skin in an aqueous medium with a reference copermeating species, [3H]methanol, and 37 degrees permeability coefficients of the pair were evaluated as functions of animal age, skin hydration, stripping of the skin, dermis isolation, and phenol concentration. Age proved to be of little consequence to permeability over a wide age range. Prolonged aqueous soaking of the skins was also without much effect. Stripping of the skin and isolating the dermis by soaking techniques allowed assessment of individual skin strata diffusion resistances. When applied to skin in trace radiochemical concentrations, phenol behaved diffusionally as an alkanol with a chain length of six. But at concentrations greater than 2% w/v, phenol facilitated the permeation rates of itself and methanol; the effect was markedly concentration sensitive and only fractionally reversible. Concentration studies using silicone rubber membranes proved that the effects on the skin were the results of destroyed barrier integrity. At 6% phenol concentration there was an essentially instantaneous, 10-fold increase in the phenol permeability coefficient, raising it to two-thirds that observed with fully stripped skin. Overall, the data suggest that the stratum corneum is proportionally impaired as the phenol concentration is increased.

Seven recommended methods for estimation of coliforms, three for fecal coliforms and four for enterococci were tested on 30 retail ground beef samples. Lauryl sulfate tryptose broth gave higher coliform counts than did MacConkey's broth or brilliant green lactose bile broth 2% in 3-tube Most Probable Number (MPN) methods. With all MPN broths, coliforms counts were significantly (P ⩽0.05) higher after 48 than after 24 h of incubation. Presumptive coliform counts were higher with surface-overlay plating on violet red bile agar than with pour plating on the same agar or with the MPN broths. However, presence of Escherichia coli Type I was not confirmed as often from the agar medium as the broths. For estimation of fecal coliforms, counts did not differ significantly (P ⩽0.05) between EC broth (45.5 C) and brilliant green lactose bile broth 2% (44 C). Enterococci counts varied significantly (P ⩽0.05) among the four methods.

A method to study the influence of hydration on skin permeability where the skin is immersed in saline for up to 30 hr and under circumstances where a steady state rate of permeation can be established in several minutes is indicated. These circumstances allow multiple, sequential runs over a period where the permeability coefficients of some chemicals are gradually changing. It has been found that the permeabilities of water, methanol and ethanol are little affected by such hydration. However, there is a doubling of the permeability coefficients of butanol and hexanol during the first 10 hr of immersion. More hydrophobic alkanols seem to be less sensitive to the protracted aqueous conditioning. In general the results indicate that there are complex molecular structure-permeability relationships operating in skin. More specifically, the hydration effects are insightful with respect to developing barrier models for skin as they are further indications that different parallel diffusional paths are followed by polar and semi- and nonpolar species.

The influence of hydration on the permeability of stripped and scalded skins of hairless mice was investigated in vitro using water and n-alkanols as test permeants. Irrespective of pretreatment, the permeation rates of water, methanol, and ethanol were unaffected by aqueous immersion of skin sections in a diffusion cell, consistent with earlier data on unprocessed skins. The permeation rates of butanol and hexanol also were insensitive to hydration, differing from earlier studies on normal, intact skin in which both solutes' rates doubled after 10 hr of soaking. Following both pretreatments, the permeability of octanol declined over the first 5-10 hr of maceration, but remained invariant thereafter. The decline was most pronounced for the scalded skins. With untreated skin, octanol permeability initially increased and then declined before assuming a constant value. This study indicates that the barrier properties of the epidermis and dermis are not particularly sensitive to extended hydration except in the case of octanol. Scalding at 60 degrees for 60 sec rapidly hydrates the skin, altering tissue permeability to about the same extent as a 10-hr (or longer) immersion in water at 37 degrees. Octanol's unique hydration profile is explained by locating the origin of permeability decline in tissue beneath the horny exterior of the skin.