隆突性皮纤维肉瘤23例临床分析

本文报告了我科1978～1990年间收治的降突性皮纤维肉瘤23例,均经组织学证实.治疗以手术切除为主,术后局部复发率为65.2%.无一例发生转移.切除不彻底是复发的主要原因.作者指出广泛切除是防止复发的主要措施,手术前后的放疗有可能减少复发.     

Visual scoring and laser Doppler perfusion imaging of skin irritancy induced by different nicotine patches

Background/aims: Local skin reactions are the most common reason for discontinuation of transdermal nicotine replacement therapy in smoking cessation programs. The aims of the present study were (1) to quantify the intensity of skin reactions induced by different types of nicotine patches and (2) to compare the clinical evaluation of skin erythema using visual scores with independently performed quantitative estimates of skin perfusion.
Methods: Thirty-three subjects were included in the study, each receiving 2 different types of nicotine patches (Nicotinell and Nicorette) and 1 type of placebo patch (Nicorette), placed ventrally on the upper arms according to a randomized protocol. Patches were removed after 24 h (Nicotinell) and 16 h (Nicorette), respectively, according to recommended application times. Visual scoring and laser Doppler perfusion imaging were performed 45 min after removal of patches, in a randomized order.
Results: Nicotinell patches induced the highest cumulative clinical score for skin irritancy. All 3 investigated patches gave rise to a slight but significant skin perfusion increase and individual visual scores and perfusion data correlated.
Conclusion The degree of skin irritancy and underlying perfusion increase induced by 1 daily maintenance dose of transdermal nicotine via a patch is low, but differs between patch types.     

Non-nociceptive capsaicin-sensitive nerve terminal stimulation allows for an original vasodilatory reflex in the human skin

A significant increase of cutaneous laser Doppler flowmetry was found before blood flow decreases with increasing pressure during a 5 mmHg min⁻¹ increase of pressure strain on the finger. Pre-treatment with a local anaesthetic or chronically applied capsaicin, resulted in the disappearance of the vasodilatory response. These results suggest an original vasodilatory axon reflex response to non-noxious pressure strain which is initiated by capsaicin-sensitive nerve terminals in the human skin.     

Benign trichogenic tumours: a report of two cases supporting a simplified nomenclature

We report two cases of a rare benign tumour of hair germ. Clinically, both were solitary, well-circumscribed, subcutaneous nodules located in the extremities. Histologically, the tumours were characterized by nests and thin cords of basaloid epithelial cells intimately associated with a cellular stroma. The basaloid cells exhibited peripheral palisading, keratinization in the form of keratotic cysts and squamoid transformation, and pilar differentiation. An unusual, but distinctive, cribriform pattern of growth was observed. There was no communication with the overlying epidermis. Abundant primitive hair germinal buds and rare more advanced abortive hair follicles were identified. These histological appearances encompass features of both trichoblastic fibroma and trichogenic trichoblastoma, thus distinguishing these neoplasms from other skin tumours and reinforcing the hypothesis that these tumours are closely related from a histogenetic point of view. The presence of overlapping histological features can be problematic for practising histopathologists who rarely encounter these conditions. With this in mind, the term benign trichogenic tumour may be more appropriate to encompass these two tumours and related neoplasms that appear to lie within the spectrum of hair follicle development.     

Sources of unwanted variability in measurement and description of skin surface topography

Background/aims: Quantitative measurement of skin roughness has proved to be a valuable tool in the efficacy-control of external applications, but it suffers from not yielding easily comparable results. The most important sources of inter-observer variability are high-pass filters used to separate roughness and waviness, and low-pass filters which result from the finite resolution of the instrument or from the finite sampling interval of digital measurement. In the present study, the effects of high-pass filters and sampling intervals on the roughness measured were investigated. Methods: Dynamically focusing optical profilometry was used to measure the surfaces of negative replicas of healthy human skin. High-pass cut-off wavelengths and sampling intervals were varied systematically. Results/conclusions: Virtually unbiased estimates for the roughness parameters K, Sk, R_q, and R_a can be obtained using sampling intervals of 40 or even 80 μm. Regarding these roughness parameters, it is far better to do more scans than to shorten the sampling interval. The roughness parameters R_z, R_p, R_t, R_pm, R_max, P_t, on the other hand are very sensitive to the influence of the sampling interval; to achieve satisfying estimates, the sampling interval should be no longer than 2 to 5 urn; as an important parameter’of the measurement, it is worthy of remark and should always be indicated. The way the mean square roughness R_q depends on the cut-off wavelength is not well described by the Sayles-Thomas-relation R_q～λ_c^0.5. If the power-spectrum |h*(v)|² approximates sufficiently to a power law, |h*(v)|²～v^δ, a better estimate is given by R_q～λ_c^γ with γ=-(δ+1)/2. In many cases, γ=1 or R_q～λ_c will suffice.     

Ⅱ孔型房间隔缺损直视修补术后心律失常的临床观察

210例Ⅱ孔型房间隔缺损术后发生心律失常90例,14种类型,共292例次,其中,室上性占96%。30例需药物治疗,93%的患者出院时恢复正常。本文着重分析心律失常的特点,讨论影响因素及预防措施。     

Preventing percutaneous absorption of industrial chemicals: the "skin" denotation

Percutaneous absorption has received comparatively little attention in occupational health, although this route of entry has repeatedly caused occupation-related intoxications. In practice, the evaluation of skin penetration rates is far from simple. Much evidence has been obtained from studies of chemicals used for cosmetics and topical therapeutics, but the information available on compounds encountered in occupational health is limited. The data obtained from experimental studies have confirmed that the concentration, type of vehicle, skin area, skin condition, and extent of occlusion are important factors in determining the degree of percutaneous absorption, but no general model has been developed. Also, too little is known about the basic chemical properties governing the rate of penetration. Thus, prediction is difficult and bound to be rather inaccurate. Current preventive practice follows the procedure used by ACGIH and is mainly based on a "skin" denotation in official listings of chemicals to which exposure limits have been allocated. The number of substances and groups of chemicals which have received skin denotation in 17 selected countries varies between 24 and 179 and a total of 275 are listed as a skin hazard in one or more countries; ACGIH lists 143. Thus, the denotation practice varies. As an unfortunate result of these discrepancies and the dichotomy of skin denotation, the absence of skin denotation may erroneously indicate that efforts to protect the skin are unnecessary. Thus, an evaluation of skin penetration potentials should be incorporated in occupational health practice as a supplement to the official denotations.     

Application of Solid-State Nuclear Magnetic Resonance (NMR) to the Study of Skin Hydration

The solid-state nuclear magnetic resonance (NMR) technique of carbon-13 cross-polarization/magic angle spinning (CP/MAS) has been successfully used to obtain high-resolution spectra of whole-thickness, hairy rat skin and to characterize the influence of hydration on the efficiency of cross-polarization and the proton spin-lattice relaxation time in the rotating frame (T1H). Spectra obtained with hydrated samples, which were obtained with 50% more accumulations, had comparable signal-to-noise ratio relative to spectra obtained with dried skin, indicating a disordering effect with the presence of water. The integrated area of spectra of low-shifted peaks rose more rapidly with increasing contact time relative to the high-shifted peaks for both hydrated and dried skin. In addition, the carbonyl intensity of the hydrated skin relative to dried skin reached a maximum at shorter times, reflecting an efficient relaxation mechanism of the protons. The shift of the peak maximum to shorter mixing times quantitatively reflects the interaction of the protons of water with the carbonyl moiety.     

Preparation of metaphase chromosomes in cell cultures derived from an aquatic reptile

Summary Cell cultures (GTS) of epithelioid nature derived from the skin of a green sea turtle,Chelonia mydas, were treated with colchicine at a final concentration of 0.5 g/ml for 16 h. Mitotic cells were harvested by brief treatment with trypsin-Versene, subjected to hypotonic solution (1% sodium citrate) and fixed in (13) acetic acid: methanol. Giemsa stained preparations were photographed on High Contrast Copy film under phase contrast optics using a bluegreen filter. The result was significant enhancement of the microchromosome portion of the complement morphologically characteristic of reptilian metaphase chromosomes. By this method it was determined that the GTS cell line retains the female diploid number of the Chelonia species.     

A multiple-pathway model for the diffusion of drugs in skin

A mathematical model for the diffusion of drugs in skin is presented.The penetration of the drug by both transcellular and intercellularpathways, as well as its interchange between these pathways,is considered. A pharmacologically motivated asymptotic limitis identified and analysed to obtain, in particular, an analyticalexpression for the flux of drug to the blood at steady state.Relevant model data is discussed, and some numerical resultsare also presented.