John M. Knox

Microbial flora of nurses' hands. III. The relationship between staphylococcal skin populations and persistence of carriage.

ABSTRACT: The hands of 50 nurses and 50 controls were tested for coagulase‐positive staphylococcus. Twenty‐eight percent of both groups were carriers. The mean staphylococcal count on the palm of the hand was 13.7 per 16 cm2 in nurses as compared to 442.7 per 16 cm2 in the control group. The number of persistent carriers was the same for each group, but 25% of all cultures from nurses were positive for Staphylococcus aureus as compared to 14.2% of the cultures from the control group. It was concluded that there was no direct correlation between high staphylococcal counts and persistence of carriage. The skin as a site of carriage of Staphylococcus aureus was found to be of greater importance in nurses than in control subjects.

THE BACTERIOLOGY OF TRICHOMYCOSIS AXILLARIS

SUMMARY. A method is described for the isolation and culture of the causative organisms of trichomycosis axillaris. Hairs from 7 cases, 6 of the yellow variety and one of the red, have been examined. Three species of Corvnebacteria were isolated from each of the 6 cases and 2 were isolated from the seventh. The species from the cases with the red granules were similar to those isolated from those with the yellow granules. It was concluded from these results that it was unjustifiable to refer to the causative agent of this disease as a single agent such as C. tenuis.

MICROBIAL FLORA OF NURSES’HANDS I. Quantitative Differences in Bacterial Population between Nurses and Other Occupational Groups

llic microbial flora ol: normal %kin lias long been deseribed in general terms. Coagiilase-nes^ative staphylotocx:i spct:ies ol: microeocci and dipluheroids have been reeognized as resident skin flora and diflerentiated from transient flora whic;]i is frequently dejjendent on the environment. More lecent stndies,however, have revealed that the mierobial flora of skin is more diverse and eomplex. Bactei ial species sueh as Mima polyni(>rj)lia, not preiotisly associated with the skin, have been deseribed as noinial floia. Fin thei more, the intrigmng problems of relationshijxs between the normal skin Ilora antl tliose organisms e;nising skin infeetion lias stimtilated otheistuilies. Ihe jKiipose of this investigation was to determine the ntimbers and distribtition of mierobial flora on the hantls of ntirsiiig jjersonnel. This knowledge might indicate what conditions promote spread of infectiotis agents and lead to hosj^ital infeetions. It was of interest as well to compare the microbial flora of hands of luirses with that of other oc:cupational grotips to determine to what extent the dilferent environment

Recognition and Diagnosis

Most failures in treatment of skin cancer can be traced to a mistake in the initial evaluation. Therefore the first important step is careful and thorough examination of the tumor. Great care should be given to determine what type the cancer is, how-large it has grown, and if it has spread. This knowledge is essential to select the most appropriate method of treatment.

Photosensitivity reactions in various diseases.

Photosensitivity is a prominent feature of various disease states. The author discusses this reaction in relation to porphyria, lupus erythematosus, pellagra, aging, carcinogenesis, xeroderma pigmentosum, solar urticaria, polymorphic light eruptions and drug-induced photosensitivity. Most cases can be managed successfully by education of the patient, protection of the skin with clothing and sunscreens, and use of appropriate systemic medications. Antimalarials are most effective in polymorphic light eruptions and discoid lupus erythematosus.

Sunlight and the skin

Abstract Most of the significant diseases in which sunlight is a causative or contributing factor were discussed in detail. Conditions receiving greatest emphasis were sunburn, photosensitivity, aging, and carcinogenesis. Patient education, protection with clothing and sun screens, and the antimalarial drugs are considered to be the basis of therapy.

THE EFFECT OF SURFACE LIPIDS ON EPIDERMAL PROTEIN

THE skin surface and hair of mammals are covered with a greasy lipid film. The functions attributed to these lipids include maintenance of hydration, permeability and resistance to exogenous infection. However, Kligman and Shelley, 1958, and Kligman, 1963, state that human sebum seems to be useless and that the sebaceous glands are probably obsolescent appendages. Surface lipids are mostly of sebaceous-gland origin and are not thought to influence keratinization since this process takes place below the level in contact with surface lipids. However, evidence suggests that keratin or the terminal phase of the keratinization process could be affected by one or more components of the surface lipid film. Kligman and Shelley suggested that stratum eorneum acts somewhat like a wick and becomes filled with surface lipids. Squalene, a major hydrocarbon constituent of surface lipid (Haahti, 1961), inactivates free sulphydryl (Flesch, 1951). Brody (1960) has shown by electron microscopy that there is a distinct difference between keratin of the basal layer and keratin of the intermediate layer of the stratum eorneum. The reason for this difference is unknown but it indicates that changes take place in keratin in the stratum eorneum. To investigate the possibility that surface lipids affect epidermal protein and to determine the manner in which they do so, this experiment was conducted. Stratum eorneum, psoriatic scale and separated epidermis were studied before and after incubation with surface Mpid to determine changes in sulphydryl concentrations and in Brdiekas total protein or filtrate reaction. The total protein reaction detects even partial denaturation of protein molecules and the filtrate reaction determines alterations in mucoprotein.

The destructive energy of sunlight.

A considerable amount of evidence implicates sunlight exposure as the most common and noteworthy cause of detectable degeneration changes in skin. These changes were previously thought to result from aging. Of major significance is the fact that skin cancers develop in these sites of actinic damage. Also, a variety of cutaneous diseases are the result of photosensitivity. Actually, sunlight-induced disease is much more common than most physicians realize, for many pathologic conditions result from the biochemical alterations that occur following absorption of the electromagnetic energy of sunlight by the skin. Because of this, it is worthwhile to discuss photodegenerative changes, carcinogenesis, photosensitivity diseases and certain biochemical changes resulting from ultraviolet irradiation.

Results of Treatment of Skin Cancers

When the results of treatment of skin cancer are analyzed, it is obvious that any of the three methods can be used to achieve a five-year cure rate of 90 per cent or better [1–9]. This is true for both basal cell and squamous cell carcinoma. Since any of these three commonly used methods of treatment, when properly applied, are capable of achieving cure rates of over 90 per cent, the physician can confidently apply the modality most suited to that particular tumor. He also can consider such secondary factors as convenience, expense to the patient, and time for patient and physician. This ability to select the method most suitable for each tumor will result in even higher cure frequencies than if one method is used almost exclusively.

Treatment of Precancerous Dermatoses

In addition to wrinkling and degeneration, sun exposure produces premalignant conditions that may eventuate in skin cancer. Included among the precancerous dermatoses are certain types of keratoses, cutaneous horn and leukoplakia. The premalignant keratoses are actinic (senile), arsenical and post-irradiation keratoses. Cutaneous horn usually begins as a hyperkeratotic actinic keratosis and, like any other actinic keratosis, may evolve into a squamous cell carcinoma. Leukoplakia, which by definition is limited to mucous membranes, is closely related to actinic keratosis.