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Biomedical subjects

B Lagerholm

Publications and source records attributed to B Lagerholm.

At least 19 recordsLinked to original sources
PubMed2001

On-line process control of liquid chromatography.

Many analytical methods are based on liquid chromatography and typically the only measure of system stability is standards, injected repeatedly throughout the sequence. In this paper, a novel approach is presented, where the analytical run is treated as a process with the chromatographic data as the product. It is postulated that enhanced quality of the data can be obtained through monitoring the process, i.e., the chromatographic system, during the sequence. For this purpose, a liquid chromatography process control (LCPC) system has been developed. Here, several parameters, e.g., the pressure at the column and the injection valve, are monitored. Chemometrics is used for interpreting the data and producing multivariate statistical process control (MSPC) charts. The chromatographic run is divided into two parts: the dynamic injection phase and the static elution phase. Two principal component analysis (PCA) models, one for each phase, are continuously created and upgraded as the data are collected. The results of the PCA are shown in the MSPC charts, and when an error detection limit is exceeded, the analyst is promptly notified. LCPC, a continuous system suitability test, provides better control of the analysis, allowing a reduction in the number of standards and replicates. Furthermore, troubleshooting is facilitated.

Journal Article↗
PubMed1995

Interleukin (IL)-1 alpha- and -1 beta-, IL-6-, and tumor necrosis factor-alpha-like immunoreactivities in human common and dysplastic nevocellular nevi and malignant melanoma.

Interleukin-1 alpha and -1 beta, interleukin-6, and tumor necrosis factor-alpha may have a protective effect against malignant transformation of melanocytes. By using monoclonal and polyclonal antisera we investigated, in paraformaldehyde-fixed tissue, the cellular distribution of these cytokines in human common and dysplastic nevocellular nevi and in malignant melanoma. Generally, the immunolabeling for all of these cytokines was both cytoplasmic and perinuclear as well as present in the basement membrane, which surrounds the individual cells or cellular nests of some of the nevi. In compound and intradermal nevi the immunolabeling was abundant, although there was a variation in the staining intensity between individual cells and even inside a single nevus cell, ranging from weak to strong. There was a strong labeling of the basement membrane around the cellular nests and around individual cells inside or outside the nests in the papillary and reticular dermis. With regard to the common junctional and dysplastic nevi and malignant melanoma, occasional immunolabeling could be seen in some cells within the cellular nests in the junctional area or papillary dermis, ranging from faint to moderate in intensity, but in this case the basement membrane around individual cells or cellular nests was not stained. The staining of nevocellular nevi and malignant melanoma indicates the possibility of these cytokines being synthesized by the nevi and melanoma cells. The labeling of the basement membrane in compound and intradermal nevi suggests that cytokines produced by nevocellular cells may be stored in the basement membrane, from which they could be released upon environmental or mechanical challenge. This distribution pattern would support the hypothesis that these cytokines may protect the common nevi from malignant transformation.

Basement Membrane↗
PubMed1994

The dominant form of hereditary palmoplantar keratoderma in the northernmost county of Sweden (Norrbotten).

The frequency of autosomal dominant inherited palmoplantar keratoderma (HPPK) in the northernmost county of Sweden (Norrbotten) is 0.55%. Histopathological examination of 91 biopsies from patients with the dominant form of HPPK revealed no case of epidermolytic PPK. This finding is in contrast to the results of a re-examination of descendants of the original family published by Thost which showed the characteristic features of epidermolytic PPK, and re-evaluation of biopsies from other families has shown that it is the most frequent type. The existence of PPK type Unna-Thost in relation to epidermolytic PPK and to HPPK of the northernmost county of Sweden will be discussed. At the same time a revision of designation of this type is proposed. A dermo-epidermal mononuclear cell infiltrate belongs to the classical description of PPK Unna-Thost. It was shown that this cell infiltrate occurs significantly more often in patients with HPPK and dermatophytosis. Relapsing vesicular eruptions along the hyperkeratotic border are a clinical sign of the severity of dermatophyte infections. Such spongiotic vesicles together with a mononuclear cell infiltrate should be considered as eczematous reaction to dermatophytosis.

Biopsy↗
PubMed1987

Acrosyringeal lichen planus.

Six patients with lichen planus or lichenoid toxicodermia are described. A dermal lymphocytic infiltrate in juxtaposition to the acrosyringium and liquefaction degeneration of the acrosyringeal basal cell layer were prominent findings. Three patients had no medication. In two there was an association with beta-adrenoceptor blocking drugs. The term acrosyringeal lichen planus is proposed for this histological picture and some explanations for its pathogenesis are suggested.

Aged↗
PubMed1986

Histopathological support of antagonism of allergen-induced mast cell mediator release in human skin by a beta-2-agonist.

The site of antagonistic action on allergen-induced early skin reactions by the beta 2-agonist terbutaline was studied by light microscopy in 10 atopic subjects. Pretreatment with 1 microgram terbutaline intradermally 5 min prior to challenge with horse dander allergen produced an approximate inhibition of 85 and 55% of flare and wheal responses respectively (P less than 0.001). Biopsy specimens obtained from skin sites injected with allergen alone showed a reduced number of remaining stainable mast cells as compared to sites injected with terbutaline prior to allergen (P less than 0.05, Sign test). The data support the concept of in vivo inhibition of the mast cell mediator release reaction in atopic skin by terbutaline.

Adrenergic beta-Agonists↗
PubMed1985

The effect of grenz rays on the expression of allergic contact dermatitis in man.

To investigate the effect of grenz rays on the expression of allergic contact dermatitis, six patients hypersensitive to nickel were studied. They were given 3 Gy of grenz rays, once a week for 3 weeks, to a defined area of the back. Twenty-four hours after the last treatment serial dilution nickel patch tests were applied on the grenz-ray-treated area and on untreated control skin. There was an almost total suppression of the allergic contact dermatitis at the site of grenz ray treatment. Biopsy specimens were taken from nickel-challenged and unchallenged skin, both from the grenz-ray-treated area and from the control area. Different cell populations in epidermis and dermis were identified by monoclonal antibodies (Leu 2, 3, 4, 7, Leu M1, B1, OKT6). In the grenz-ray treated epidermis there was a pronounced reduction of OKT6-positive cells, regarded as Langerhans cells. No other differences were observed between control and grenz-ray-treated skin. Our results suggest that Langerhans cells might be required also for the effector phase of the allergic contact dermatitis.

Adult↗
PubMed1983

Patch testing with sodium tungstate.

Hard metal contains about 90% tungsten carbide. In an investigation of the skin of 853 individuals who are still working or had previously worker in hard metal manufacture, sodium tungstate was included in a patch test with a panel of substances from the environment of the employees. No allergic reactions to tungstate were found. However, irritant pustular reactions appeared in 2.0% of the patch tests. The pustular reactions were often reproducible.

Dermatitis, Contact↗
PubMed1983

Purpura provoked by cold exposure in a skier.

Case of a previously healthy young skier who developed purpura on his lower legs after cold exposure; the patient was not taking any medicine. No disease or disturbance except the physical trauma of cold could be found to explain his purpura.

Adolescent↗
PubMed1983

Long-term photochemotherapy for psoriasis: a histopathological and clinical follow-up study with special emphasis on tumour incidence and behavior of pigmented lesions.

A thorough clinical and microscopical investigation was conducted in patients with severe longstanding psoriasis maintained on long-term photochemotherapy with PUVA. 250 patients were reinvestigated after PUVA therapy for up to 7 years, 49% for 5 to 7 years. No serious side effects were observed. Occasional peculiar hyperkeratoses of a bowenoid type were seen in 3 patients (1.2%) and solitary lesions at actinic keratoses in 5 patients (2%). No occurrence of squamous cell carcinoma nor basal cell carcinoma was detected. Lentiginosis of varying degree was fairly common and seen in 33% and a very profuse disseminated lentiginosis in 4%. Six patients (2.4%) developed isolated, clinically dark and irregular lentiginous spots which on biopsy showed microscopically an aberrant morphology and were therefore classified as atypical lentigines. All of them had earlier been subjected to extensive courses of UVB treatment and 3 of them had history of earlier arsenic therapy. No malignant transformation was seen but those were for reasons of safety referred to the risk group category and may prove to be at particular risk on future PUVA therapy.

Adult↗
PubMed1982

The influence of PUVA treatment on the substructure of nevocellular nevi in psoriatic patients.

The influence of PUVA treatment on junction A-cell nevi in psoriatic patients has been analysed. After long-term PUVA therapy the nevocytes display an obvious increase in melanosome synthesis. The melanosomes are clearly polymorphous, without any predominant configuration. The structural organization of the melanosomes is profoundly aberrant. Formation of autophagosomes is conspicuous. The cytoplasmic filaments are displaced peripherally. No convincing signs of malignancy are observed electron microscopically. Light microscopical findings of a bridging proliferation of nevocytes between junction nests is a precautionary observation, however.

Adolescent↗
PubMed1982

Leukoderma syphiliticum: ultrastructural observations on melanocyte function.

A case of genital leukoderma syphiliticum was analysed submicroscopically. No treponema pallidum organisms could be detected intra- or extracellularly in the epidermis or in the dermis. The melanocytes were only slightly reduced in number and had mostly normal outlines. The melanogenesis was impaired and small melanosomes with decreased deposition of melanin were mostly produced at the expense of normal melanin granules. A partial block in the melanin transfer mechanism seems to be in evidence. As no direct destructive action of spirochetes on the melanocytes is observed, an indirect effect is assumed, e.g. by a tyrosinase inhibitor.

Adult↗
PubMed1979

Acne keloidalis of the burned male face. Case report.

Acne keloidalis is characterized by infected keloid-like nodules in the short-cut nuchal region probably caused by recurving, ingrowing hairshafts. A case with a deep, partial-thickness burn of the hair-bearing part of the face of a man is reported. After healing, the patient started shaving himself thus inducing a severe state of acne keloidalis. It seems advisable in males not to shave during the first eight eight to ten months after a partial-thickness burn of the face in order to avoid this troublesome condition.

Acne Keloid↗
PubMed1979

Mucinosis follicularis provoked by light exposure.

The present paper reports a study on a case of follicular mucinosis exacerbated by sunlight exposure. Provocation with standardized light testing was carried out on both normally pigmented skin and on areas of hypopigmentation representing a residual state after earlier skin lesions but without any signs of active mucinosis follicularis. Typical clinical and histologically verified lesions were provoked by the light test procedure, best seen in hypopigmented areas but with similar changes in normally pigmented skin. Characteristic findings developed gradually, assuming an appearance identical with that of the observed spontaneously elicited lesions after 3--4 weeks. Treatment with carotenoids periodically over several years has provided a proper light protective effect, as only minimal lesions have been noted during these periods, compared with extensive changes during similar periods without treatment.

Adult↗
PubMed1979

Light and electron microscopic aspects of pemphigus herpetiformis (eosinophilic spongiosis) in comparison with other acantholytic disorders.

Histopathological and electron microscopic analyses of pemphigus herpetiformis in a 64-year old woman with a previously operated atoxic goitre and suffering from a nephrotic syndrome and a chronic non-aggressive hepatitis revealed acantholysis preceded by eosinophilic spongiosis. Light microscopically the acantholysis is characterized by the occurrence of necrobiotic epidermal cells. No dyskeratotic cells are found. The mechanism of acantholysis depends on an exuberant elongation of desmosomes, leading to their disruption, spongiotic acantholysis. A conspicuous convolution of specific tight intercellular spaces is observed. Intracytoplasmatic occurrence of such tight intercellular spaces is seen in sections. Pseudomyeloid bodies of various types seem to be of significance. Particles closely similar to pox viruses are observed. The acantholytic process is compared with other acantholytic disorders in which the above-mentioned findings were not observed.

Acantholysis↗
PubMed1978

Submicroscopic aspects of the keratinization, dyskeratinization and acantholysis of fogo selvagem.

Histopathological, cytomorphological and electron microscopic analyses in a case of fogo selvagem are reported. Contradictory to the light microscopical findings, the acantholysis as seen with the electron microscope involves the basal layer but not the subcorneal layers--at least not the most superficial part of the granular layer. A conspicuous disintegration of the tonofilament-desmosome complexes give rise to the concomitant dyskeratosis. This aberrant process, including an association between retracing tonofilaments and defective Odland bodies, results in the terminal stage of monstrous defective and specific keratohyalin. In cytoplasm, target-like structures similar to virions of the herpes virus group were observed. The dynamics of the pathological process is discussed.

Acantholysis↗