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Biomedical subjects

C L Gummer

Publications and source records attributed to C L Gummer.

16 recordsLinked to original sources
PubMed2002

Cosmetics and hair loss.

Cosmetic hair care products are often implicated by the user or the clinician in cases of hair loss. Yet, these products are used ad lib, in a wide variety of home conditions and on a wide variety of hair types, by millions of consumers every day with no adverse effects. Based on this extensive data set, the absence of literature reports, and a detailed understanding of the mode of action of cosmetic hair care products, we can conclude that they do not cause hair loss. Clinicians investigating cases of hair loss must fully appreciate the hair cycle, the length of time a single fibre may be present on the head, and its biological and cosmetic history in order to understand the causes of hair loss and make the correct diagnosis. With a better understanding of the cosmetic practices used by everyday consumers, the clinician will be in a strong position to help patients re-grow their hair and guide them through a high quality hair care regime.

Alopecia↗
PubMed1994

2-in-1 shampoo technology: state-of-the-art shampoo and conditioner in one.

Consumers have expressed a need for cleaning and conditioning in one step. Conventional shampoo technology using anionic surfactants and cationic conditioners results in charge interaction and complexing of the ingredients. Neither shampoo nor conditioners achieves the desired result. The successful solution was to incorporate charge neutral dimethicone conditioning ingredients, suspended as microfine droplets within complex crystal lattices, into anionic surfactant shampoo technology. The same solution has also been applied to amphoteric surfactant systems. This provides complete cleaning, and hair conditioning fully equal to separate conditioners without the problems of sebum interactions and conditioner build-up. This was achieved by keeping the dimethicone in suspension throughout the shampoo process. During rinsing, excess water breaks the crystalline lattice and allows deposition of the dimethicone droplets onto the hair. Full cleaning and conditioning are, therefore, achieved in one application. Dimethicone build-up is not encountered as subsequent washes first remove soil and previously deposited dimethicone. Neither do neutral dimethicones show any reactions with sebum. The development of effective 2-in-1 technology has had a major impact on shampoo technology and consumer habits and practices. This has significantly changed the way consumers care for their hair.

Hair↗
PubMed1989

Loose anagen syndrome.

A distinctive new hair condition, the loose anagen syndrome, features anagen hairs that are loosely anchored and easily pulled from the scalp. The children studied had sparse hair that did not grow long and that pulled easily from the scalp. The majority of patients were blond girls, aged 2 to 5 years, but both sexes and those with dark hair can be affected. The hair was not fragile, and easily pulled hairs were misshapen anagen hairs without external root sheaths. Histologic examination of the hair showed abnormal premature keratinization of Huxley's and Henle's layers of the inner root sheath in some samples. Length and density of hair gradually increased with age, but anagen hairs remained loosely anchored in adulthood. This report describes findings in 22 children and five adults with the loose anagen syndrome.

Adult↗
PubMed1986

The penetration of [14C]ethanol and [14C]methanol through excised guinea-pig skin in vitro.

We have studied the penetration in vitro of methanol and ethanol through excised, full thickness, guinea-pig skin. The total amount of methanol or ethanol that penetrated the skin over a period of 19 hr was in the order of 1% of the total dose. Neither compound appeared to show an increase in penetration with increasing dose volume. Penetration of both methanol and ethanol was significantly enhanced by occlusion. The amounts of both compounds that penetrated, and the profiles of the amount penetrating per hour, were significantly influenced by the nature of the occlusive material. Under occlusion and in the presence of either compound the barrier properties of the skin appeared to be altered so that 'fluid' was lost from or through the skin to the air space bounded by the occlusive material.

Animals↗
PubMed1986

Animal models for percutaneous penetration: assessing contamination of the experimental system.

We have used both quantitative and qualitative procedures to assess the validity of percutaneous penetration data obtained from the guinea-pig in vivo. Our results indicate that, under certain, not unusual, experimental conditions the results may be misleading and should be viewed with caution. Contamination of the experimental system, either by simple desquamation from the site of application, or trauma to the site such as rubbing or scratching, may greatly influence the results. We conclude that simple control experiments similar to those described should be conducted when using in vivo animal models for studies on percutaneous penetration, and particularly where the subject is not totally immobilized.

Animals↗
PubMed1985

Trichothiodystrophy: an ultrastructural study of the hair follicle.

We have used detailed ultrastructural and electron histochemical techniques on both the hair shaft and anagen hair follicle to elucidate further the structural abnormalities in trichothiodystrophic hair. We have shown that protein deposition in the follicle is reduced and lacks orientation, and that the anagen follicles show an overall distortion. Both the hair cuticle and cortex high sulphur protein components are affected. The results of this study help to give a visual interpretation to detailed biochemical studies conducted by other workers thereby allowing specific localization of the site of the intrinsic keratin abnormality.

Child, Preschool↗
PubMed1984

Trichothiodystrophy: an electron-histochemical study of the hair shaft.

We have used sensitive electron-histochemical methods to study the subtle ultrastructural variations of cystine incorporation into the hair shaft in trichothiodystrophy. We have shown a general reduction in the cystine (sulphur) content of both the cuticle and the cortex. Discontinuity, and in some cases, complete absence of the cuticular A-layer results in premature weathering of the cuticle and weakening of the hair shaft. The ultrastructural findings support the work of Gillespie & Marshall (1981) in demonstrating the absence or re-characterization of the high sulphur matrix proteins and show further evidence for the incorporation, and abnormal distribution and deposition of sulphur-rich proteins in the hair cortex and cuticle. We conclude that the similar yet different results obtained from each patient's hair sample are characteristic of trichothiodystrophy, a neuro-ectodermal symptom complex which may represent a final common pathway of more than one metabolic disturbance.

Cystine↗
PubMed1983

The distribution of Mycobacterium leprae in the hair follicle of the eyebrow.

Longitudinal sections of hair follicles from the eyebrows of patients with active, untreated, lepromatous leprosy were studied. Mycobacterium leprae were found in the dermal papilla and outer root sheath of both anagen and telogen hair follicles. Bacilli were rarely found in those cell lines continuous with the environment, i.e., the hair shaft and the inner root sheath. The biochemical fate of these cell lines is such that they would not provide a suitable medium for the survival and transport of bacilli into the environment. We conclude that it is unlikely that the hair follicle plays a significant role in the dissemination of M. leprae but it may be important in providing a suitable site for the incubation of the bacillus within the dermis.

Eyebrows↗
PubMed1982

Kwashiorkor: an electron histochemical study of the hair shaft.

Previous studies on hair in kwashiorkor have been equivocal regarding the normal or abnormal incorporation of amino acids into the hair shaft. In this study we have applied a sensitive electron histochemical technique to transverse sections of scalp hair from children with severe kwashiorkor in order to study its ultrastructure and the incorporation of sulphur-containing amino acids (cystine). We have found no evidence to support the idea that a protein deficient diet in the weaning or post-weaning period directly affects the distribution and relative amounts of sulphur-containing amino acids in the hair shaft in this disease.

Child↗
PubMed1981

Monilethrix: an electron microscopic and electron histochemical study.

We have carried our electron microscopic and electron histochemical investigations on affected hair follicles and hair shafts to elucidate further the structural abnormality in monilethrix. The structural abnormalities manifest in the cortex and cuticle of the hair shaft could be traced to the locality of the 'zone of keratinization' of the follicle. Abnormal orientation of the cortical cell proteins, folding of the cuticle cell membrane and varying amounts of endocuticular material were all observed in the region prior to full keratinization. We observed structural abnormalities within all the component layers of the inner root sheath adjacent to the faults within the hair shaft, indicating a possible asynchrony within the monilethrix follicle.

Hair↗
PubMed1981

Pili annulati: electron histochemical studies on affected hairs.

In this study we have shown that in pili annulati all the normal layers within each cuticle cell are present, and show a normal distribution of cystine. The presence of well ordered macrofibrils, composed of microfibrils embedded in a cystine rich matrix, in both regions of the hair shaft indicates that normal keratinization can and does take place. We have demonstrated the presence of electron-opaque, cystine positive material at the intermacrofibrillar spaces and suggest that the presence of the cortical holes is in part due to insufficient cortical material to occupy the space available, and in part due to the dissolution of the intermacrofibrillar material, possibly by water of other chemical agents, diffusing through an apparently more permeable cuticle.

Cystine↗
PubMed1980

Generalized trichorrhexis nodosa.

A case of generalized trichorrhexis nodosa is described in a man. Electron histochemical studies showed abnormal staining consistent with a definite disorder in the formation of alpha-keratin chains within the globular matrix of the hair cortex with respect to cystine; keratin amino-acid analysis also revealed low cystine. This cortical change, together with multiple vacuoles found in the endocuticle, are evidently the intrinsic defects which allow relatively trivial chemical and physical trauma to cause trichorrhexis nodosa.

Amino Acids↗
PubMedDate not supplied

Elucidating penetration pathways into the hair fiber using novel microscopic techniques.

Much controversy exists regarding the route of penetration of molecules into hair fibers. In brief, there are two schools of thought. The first argument is that molecules enter the hair fiber via the cell membrane complex (cmc) of the cuticle and then diffuse throughout the cortex via both the intercellular cement and the bulk of individual cortical cells. The second approach concludes that entry to the fiber is via the endocuticle and other non-keratinous parts of the fiber. In the latter case the cmc is definitely not considered to have a role in the penetration of molecules into the fiber. The tools available for studying penetration into the fiber, e.g., light and electron microscopy, mean that it is usually only possible to extract static information from a dynamic process. Similarly, great care is needed in the interpretation of images produced by the various techniques. Where a molecule is seen to end up does not always indicate how it got there! In these studies I have used novel derivations of conventional electron microscopic techniques, combined with early photographic chemistry, to elucidate further the pathways of penetration into the hair fiber. From these studies one can conclude that both arguments describing penetration into the fiber are complementary, valid, and highly relevant. The techniques allow one to visualize material within the cell membrane complex of the cuticle. In addition, these studies show that the high-sulphur proteins of the cuticle, usually considered as highly cross-linked and inaccessible, are easily penetrated. Therefore, all of the structures within a hair fiber should be considered as penetration routes into the hair fiber for the delivery of industrial and cosmetic materials, even though they may not form continuous pathways throughout the hair. The hair should be viewed as a structure composed of a number of compartments of differing capacity, chemistry, and accessibility, rather than as continuous pathways from the surface to the center of the fiber.

Animals↗