Per-Åke Hofer
Umeå University
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Featured researches published by Per-Åke Hofer.
Virchows Archiv | 1984
Kerstin G. Helander; Per-Åke Hofer; Göran Holmberg
The aim of this study is to provide karyometric data which may be of value in the grading of urinary bladder tumours. For this purpose 27 biopsies were studied: four from normal bladder mucosae, eleven from grade I tumours, six from grade II tumours and another six from grade III tumours, according to a I–IV scale. After standardized fixation and plastic embedding, semithin sections were used for light microscopic stereology. Mean profile areas and mean volume densities of the nuclei tended to be higher in the more malignant cases. The nuclear volume densities were significantly higher in grade II than in grade I. The most important finding relates to the large nuclear profiles (> 90 µm2), which were found almost exclusively in grade III tumours. Simple measurements of nuclear size can thus provide objective data to aid in the diagnostic procedure.
Acta Oncologica | 1990
Christer Lindholm; Per-Åke Hofer; Håkan Jonsson
Histological sections of 50 clinical stage I cutaneous melanomas were analyzed by single cell DNA cytophotometry. Forty-two percent of the melanomas had diploid modal values. Ploidy was not significantly related to the level of invasion, melanoma thickness or prognosis. These results are contradictory to published data from flow cytophotometry which, however, differ inter alia concerning patient materials and follow-up times. Mean nuclear area was in our study significantly correlated to the prognosis.
Virchows Archiv B Cell Pathology Including Molecular Pathology | 1989
Christer Lindholm; Per-Åke Hofer; Håkan Jonsson; Bernhard Tribukait
SummaryIn a retrospective study flow cytometry was performed in 82 paraffin-embedded clinical stage I cutaneous melanomas. A significant correlation of ploidy to melanoma thickness was found. Using a log rank test ploidy was found significant for prognosis. However, using the Cox’s proportional hazard test the influence of ploidy vanished and melanoma thickness or Clark level of invasion together with sex and location were the factors most important for prognosis.
Virchows Archiv B Cell Pathology Including Molecular Pathology | 1987
Christer Lindholm; Kaj Bjelkenkrantz; Per-Åke Hofer
SummarySingle cell DNA cytophotometry was used to characterize seven compound, ten intradermal and six Spitz naevi as well as 23 primary cutaneous malignant melanomas.Compound and intradermal naevi were characterized by a smaller nuclear area than both Spitz naevi and malignant melanomas. Tumour ploidy could not be used as a single criterion of malignancy since both diploid and hyperdiploid melanomas were encountered. The very low mean optical density of Spitz naevi served to distinguish these lesions from malignant melanomas.
Acta Dermato-venereologica | 2003
Lena Wennerstrand; Melker Häggbom Klingberg; Per-Åke Hofer; Anita Lundström; Lisbet K. Lind
Sir,Palmoplantar keratodermas (PPKs) constitute a hetero-geneous group of skin disorders with the distinctivetrait of hyperkeratosis of palmoplantar skin. Thedisorders are classified clinically by the morphologyand distribution of the hyperkeratosis, the presence ofassociated cutaneous and non-cutaneous features andby the mode of transmission (1, 2).Familial diffuse epidermolytic PPK (EPPK) is themost studied keratoderma and is characterized bygranular and vacuolar degeneration of the cells of thespinous and granular layer. All mutations reported todate, with one exception, are locatedinthekeratin9gene(KRT9)onchromosome17(1,3). The majority of KRT9mutations reported are missense mutations in exon 1of the KRT9 gene, but there are reports of a stopcodon mutation in exon 1 (4) and of a 3 base pairinsertion in exon 6 (5). The position most frequentlyreported to be mutated in KRT9 is the arginine codonat position 162 in exon 1. In addition to KRT9 mutations,there is a recent study revealing a splice site mutationin the KRT1 gene as the cause of mild EPPK (6).The KRT9 gene appears to be the only keratin genewhose expression is restricted to palmoplantar epider-mis (7, 8). Consequently, individuals that carry amutation in the keratin 9 gene only display the effect ofthe mutation in the palmoplantar skin.Here we report the first observation of a Swedishfamily with EPPK and the attribution of the disorder toa de novo mutation in KRT9.MATERIALS AND METHODS
Acta Oncologica | 1988
Christer Lindholm; Per-Åke Hofer; Håkan Jonsson
A material consisting of 82 stage I cutaneous melanomas was analysed clinically, histopathologically and karyometrically. High age, deep Clark level of invasion and thick melanomas were associated with a negative prognosis. There was a good correlation between the nuclear area and the melanoma thickness. By applying Coxs proportional hazard method to clinical, histopathological and karyometric data, it was demonstrated that karyometry provided both prognostic and biological information. Both a large variation (percentile 90-percentile 50) in nuclear area and a large standard deviation of form factor was related to a negative prognosis (p less than 0.0003 and p less than 0.04 respectively).
Nephron | 1985
Bengt Lindqvist; Anders Wahlin; Bo Lundström; Per-Åke Hofer
7 middle-aged males with bilateral, polycystic, nonfamilial kidneys without enlargement are described. The histological examination revealed multiple cysts of varying sizes and changes such as in interstitial nephritis. 6 of the patients had hematuria and/or calculi in the urinary tract. The etiology of the cysts is not clear. The picture does not conform to that of congenital cystic kidney. The cysts might possibly be a final phenomenon in contracted kidneys, so-called acquired cystic disease, but it should be noted that in 4 of the 7 cases the cystic degeneration was demonstrated log before the uremia appeared. Another possibility is that the cystic transformation described here might be attributed to a specific type of interstitial nephritis.
Acta Obstetricia et Gynecologica Scandinavica | 1982
Juhani Hoist; Per-Åke Hofer; Stefan Cajander; Bo von Schoultz
Percutaneous administration of estrogen has recently been developed into an alternative therapy for postmenopausal replacement. It is possible by the percutaneous route to achieve circulating estrogen levels and therapeutic effects similar to those following oral administration. In comparison, topical application gives a more prolonged effect and the first pass liver metabolism is avoided. These kinetic features may theoretically be advantageous, as some side effects of oral estrogen therapy may reflect enhanced hepatic action. When discussing the percutaneous route as an alternative the possible local effects of estrogen should be considered. Evidence exists that the skin is a target tissue for several steroid hormones (1). In the present study, skin biopsies were examined before and after 6 months of postmenopausal replacement therapy with percutaneous estradiol-170.
Acta Ophthalmologica | 2009
Ola Sandgren; Per-Åke Hofer
Abstract The present study is an evaluation of the possibility of using conjunctival biopsies for establishing the diagnosis of systemic amyloidosis of neuropathic type. Amyloid deposits were demonstrated in conjunctival biopsies from 15 of 16 patients with polyneuropathy and from 1 of 4 patients with vitreous opacities as the only symptom. Thus the sensitivity of conjunctival biopsies for the diagnosis of systemic amyloidosis of this type is similar to that of biopsies from other tissues. It is concluded that a conjunctival biopsy is a useful diagnostic tool since the technique is simple and there is little discomfort for the patient.
Human Molecular Genetics | 1994
Lisbet K. Lind; Anita Lundström; Per-Åke Hofer; Gösta Holmgren