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Biomedical subjects

R J Thomsen

Publications and source records attributed to R J Thomsen.

At least 19 recordsLinked to original sources
PubMed2001

Establishment of primary human meningiomas as subcutaneous xenografts in mice.

Meningiomas are the most frequently occurring benign central nervous system tumours. We determined whether a subcutaneous animal model of meningioma was feasible by implanting fresh meningioma tissue from six patients into 60 athymic (nude) mice, either as tissue blocks (38 mice) or as cell suspensions (22 mice). The tumour take-rates were 74% (block) and 50% (suspension), and the xenografts retained the original tumour grade and subtype morphology by light microscopy. Comparison of cell proliferation markers in xenografts and original tumours gave similar immunohistochemical score rates for Ki-67, but not for PCNA. With the exception of one atypical tumour surgical specimen, all tumours lacked p53 immunopositivity. Transmission electron microscopy of sections of tumour xenografts revealed ultrastructural features, including desmosomes and desmosome-like structures, characteristic of well-differentiated meningiomas. The xenografts grew progressively with a volume increase of more than 10-fold over 6-11 months and an apparent doubling time of 16 weeks. This study demonstrates the utility of the subcutaneous meningioma xenograft as a model for further biological and therapeutic studies.

Adult↗
PubMed1999

Dr. Lippes and his loop. Four decades in perspective.

Forty years ago Jack Lippes, M.D., hand made the first models of his "Double-S" intrauterine contraceptive device (IUD). Subsequently the Lippes Loop became the standard against which other IUDs came to be compared. Though millions of loops have been used, they have mostly been supplanted by copper-bearing, T-shaped devices. Due to the implant nature of IUDs, on occasion a patient presents well into menopause still bearing a Lippes Loop or other early IUD. Although there is no established causal evidence linking IUDs retained after menopause and cancer or other significant problems, such retention does confuse the diagnosis of post-menopausal bleeding and makes difficult such procedures as endometrial biopsy and ultrasonic endometrial evaluation. When contraception is no longer an issue, it is prudent to remove IUDs since they may cloud future necessary evaluations.

Adult↗
PubMed1998

Spirituality in medical practice.

Body, mind, and spirit are integrally connected. Medical training in the Western world has been strong concerning the more easily measured physical aspects, and on the mental needs it has been virtually mute on how to minister to the spiritual needs of our patients. Learning the spiritual aspects of medical care is not a typical part of the medical school curriculum, and yet it is emerging as something that our patients want and expect us to do as part of our caring for them. Herein I discuss the role of spirituality in medical practice, how it relates to alternative medical practices, methods to use to grow spiritually, and ways to apply your spirituality to medical practice.

Humans↗
PubMed1996

Subcellular distribution and photocytotoxicity of aluminium phthalocyanines and haematoporphyrin derivative in cultured human meningioma cells.

The photocytotoxicity characteristics of aluminium phthalocyanine chloride (AIPc), aluminium phthalocyanine disulphonate (AlS2Pc), aluminium phthalocyanine tetrasulphonate (AlS4PC) and haematoporphyrin derivative (HpD) were compared using primary cultures of human meningioma cells. Cells were preincubated with the photosensitising agent for 16 h, then illuminated for 15 min with broad band red light (5 OW/cm2). The resultant cytotoxicity was assessed by tetrazolium (MTT) reduction 24 h later. AlPc was found to be 400, 10,000 and 250 times more potent that AlS2Pc, AlS4Pc and HpD, respectively, as an in vitro photosensitizing agent for meningioma cells. The subcellular localisation of AlPc, AlS2Pc, AlS4Pc and HpD in meningioma cells was determined by confocal laser scanning microscopy. None of the agents localized to the nucleus. The distribution of ALPc was quite diffuse through the cytoplasm. In contrast, AlS2Pc and AlS4Pc were localized vesicles suggestive of lysosomes, and HpD in membranous organelles distinct from mitochondria. AlPc and HpD were tested with five different meningioma samples and provided a range of IC50 values from 0.009 to 0.022 OM and from 3.5 to 6.5 OM, respectively. When the MTT assay with AlPc was performed 0, 24, 48 and 72 h after illumination, the mean IC50 values were 0.25, 0.037, 0.019 and 0.012 OM, respectively, indicating that the cytotoxic effect continued to increase up to 72 h. Cells were incubated with AlPc and HpD for different times up to 24 h before exposure to light. AlPc cytotoxicity was half-maximal with an incubation time of 8 h, whereas HpD cytotoxicity was half-maximal with an incubation time of 2 h, implying slower uptake kinetics for AlPc than for HpD. These data indicate unique features of AlPc which suggests its application as a potent, non-toxic photosensitizer in the photodynamic therapy of human meningiomas.

Brain Neoplasms↗
PubMed1990

Prolonged benefit in the treatment of chronic idiopathic urticaria with astemizole.

A double-blind clinical trial of 51 patients with chronic idiopathic urticaria using oral astemizole for 8 weeks demonstrated significant improvement in symptoms and lesions in 75% of treated patients versus 20% in the placebo group. The suppression of urticaria persisted for an average of 38 days, demonstrating the long duration of action of astemizole.

Astemizole↗
PubMed1986

First patient.

Explore the source record for details and available documents.

Child↗
PubMed1985

Ultrasonic visualization of NORPLANT subdermal contraceptive devices.

This article describes the first use of ultrasound in locating in vivo NORPLANT subdermal contraceptive implants. Providing low dose, continuous contraception for women. the NORPLANT system utilizes Silastic tubing filled with levonorgestrel. The progestin-filled tubing is not radiopaque. Anticipating the large scale use of NORPLANT subdermal implants, the potential, but rare problem of difficult localization of an implant is recognized. The feasibility of using ultrasound for the painless and safe localization of NORPLANT rods and capsules is demonstrated.

Arm↗
PubMed1982

Comparative effect of isotretinoin and etretinate on acne and sebaceous gland secretion.

Isotretinoin (13-cis-retinoic acid) was compared with the aromatic retinoid, etretinate, in patients with severe nodulocystic acne. Evaluation of fifty-six such men receiving 1 mg/kg of one or the other of these two drugs was performed with regard to clinical improvement and change in sebum production. Lesion counting demonstrated a significant improvement in patients receiving isotretinoin, particularly in facial lesions. There was significantly less improvement with etretinate. Similarly, isotretinoin produced a marked suppression of sebum production. There was little effect of etretinate on sebum production. Side effects were limited primarily to the skin and mucous membranes.

Acne Vulgaris↗
PubMed1982

Pachyonychia congenita: surgical management of the nail changes.

The fingernails of a woman with pachyonychia congenita were ablated by several different methods. The most effective, most rapidly performed, and most acceptable method was vigorous curettage and electrofulguration of the matrices and beds of the nails. The responses to treatment suggest that the matrix, rather than the bed, is the site from which the abnormality of the nails develops in pachyonychia congenita. Removal of the nail beds is not necessary to prevent recurrence of deformed nails, but it may reduce hyperkeratosis in their sites.

Adult↗
PubMed1980

Topical clindamycin treatment of acne. Clinical, surface lipid composition, and quantitative surface microbiology response.

A double-blind study has been conducted to examine the effect of topical 1% clindamycin hydrochloride hydrate in a hydroalcoholic vehicle as compared to the effect of the vehicle alone. Fourteen patients applied clindamycin or vehicle alone twice daily for eight weeks. Free fatty acid surface lipid percentages, quantitative bacterial counts, and clinical response were assessed every two weeks. A significant reduction (88%) in the percentage of free fatty acids in the surface lipids was seen in the clindamycin-treated group and not in the vehicle-treated group. There was no significant change in the surface microflora. Despite the short duration of treatment, objective clinical improvement was seen in three of nine treated patients, while none was observed in the placebo-treated patients.

Acne Vulgaris↗