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Biomedical subjects

H Martin

Publications and source records attributed to H Martin.

At least 253 records · Page 14Linked to original sources
PubMed1986

Co-ordinate expression of BI.3C5 and HLA-DR antigens on haemopoietic progenitors from chronic myeloid leukaemia.

Haemopoietic cells isolated from the peripheral blood of patients with chronic myeloid leukaemia (CML), have been extensively purified and enriched using either Percoll density gradients or Percoll density gradients combined with elutriation. The quantitative expression of the BI.3C5 associated antigen and the co-expression of BI.3C5 and HLA-DR antigens on these two populations has been studied using either single or simultaneous two colour FACS sorting, following by in-vitro culture for single and multilineage haemopoietic progenitors thus obtained. The data show that the CFU-GEMM are always found in the most strongly BI.3C5 positive fraction, irrespective of the separation procedure and that the bulk of the CFU-GEMM co-express BI.3C5 and HLA-DR. The cell types initiating these CFU-GEMM are morphologically immature blasts. The more mature cells of the myelomonocytic and erythroid lineages forming single lineage colony types show variable BI.3C5 expression, although most are HLA-DR positive. Such enriched populations of malignant progenitors could provide a useful source of material to study both gene expression and the molecular mechanisms underlying malignant transformation.

Antibodies, Monoclonal↗
PubMed1986

Bier's spots reconsidered: a tale of two spots, with speculation on a humerus vein.

It is a widely accepted opinion that some of the spots produced on the forearm and hand by external compression of the brachial artery are the visible evidence of an intraosseous shunt in the humerus. These spots were first evaluated systematically by Bier in 1898. Additional studies were conducted by Rehberg and Carrier in 1922 and by Wolf in 1924, the latter's conclusions providing the currently accepted view. We examined these spots with laser Doppler velocimetry and found no differences in cutaneous perfusion among spots of different coloration. Further, there was no difference between any of the spots produced by occluding the brachial artery and values obtained from the forearm of postmortem subjects. It appears that the differences in coloration are not due to an intraosseous vascular shunt at the level of the mid humerus but, instead, are due to a capacitance phenomenon with venodilation in the dark areas and venoconstriction in the pale areas.

Brachial Artery↗
PubMed1986

Purification of haemopoietic progenitor cells from patients with chronic granulocytic leukaemia using percoll density gradients and elutriation.

Purification of haemopoietic progenitor cells from chronic granulocytic leukaemia buffy coat preparations requires a multistep approach using complementary cell separation techniques. In this study Percoll density gradient centrifugation and centrifugal elutriation were used to isolate large numbers of immature progenitor cells. Percoll density gradients were valuable as a first separation step: CFU-GM and CFU-GEMM could be enriched 75-fold in a light density fraction of d less than 1.056 g/ml and the technique could be adapted to cope with more than 10(10) buffy coat leucocytes. Progenitors cells were concentrated 3-fold by elutriation used as single method to separate buffy coat cells or when used to purify further light density Percoll fractions. When Percoll gradients and elutriation were used sequentially, undifferentiated mononuclear cells were enriched to more than 90% purity and between 5% and 40% of these cells formed CFU-GM or BFU-E colonies consisting of more than 40 cells. The enriched fractions were further characterized with monoclonal antibodies. The density and elutriation profiles of these colony forming cells resembled corresponding profiles of cells that reacted with the monoclonal antibody BI-3C5, which recognizes an antigen on primitive haemopoietic progenitor cells. Physical separation methods are a valuable first stage in the attempt to procure relatively pure myeloid progenitor cell populations, whose characteristics can then be further studied at a cellular or molecular level.

Cell Separation↗
PubMed1986

[Importance of immunohistochemistry for neuro-oncology. II. Localization of factor VIII-associated proteins and glial fibrillary acidic protein (GFAP) in angiomatous and sarcomatous tumors].

Immunhistochemical methods utilizing specific antibodies against Factor VIII-related antigen and glial fibrillary acidic protein were employed in studies of 48 intracranial and intraspinal tumors. Factor VIII-related antigen occurred only in endothelial cells of the vascular wall and is therefore not of importance for the differential diagnosis of CNS tumors. Isolated Factor VIII positive cells in the stroma of hemangioblastomas turned out to be mast cells which may also normally contain this substance. The GFAP positive cells in hemangioblastomas are believed to all be of astrocytic lineage. Many of the multinuclear giant cells present in monstrocellular sarcomas contained GFAP but were Factor VIII negative. Genuine fibroxanthoma of the meninges can apparently exist next to pleomorphic xanthoastrocytomas. As demonstrated by one of our cases, the demonstration of GFAP alone can successfully distinguish between them.

Antibodies, Neoplasm↗
PubMed1986

Fibrinolytic treatment by infusion of streptokinase-plasminogen-complex (activator): laboratory effects.

144 patients were treated with 50.000 or 100.000 fibrinolytic units (U) activator per hour over a period of up to 5 days. The drug is not yet available but in trial for the time being. We report on a survey of laboratory results in 32 of these patients. The plasminogen content of 100.000 U activator is comparable to the plasminogen content of 29 ml plasma. During activator infusion laboratory findings showed a moderate fall in plasminogen and fibrinogen. Plasmin activity was measurable during the whole period of treatment while antiplasmin was lowered considerably. There was a distinct hypocoagulabilty during activator infusion visible by a prolongation of the thrombin time and aPTT. Interestingly, no measurable activator or streptokinase activities appeared in the plasma during activator infusion. This is in contrast to findings with conventional streptokinase infusion schemes.

Aged↗
PubMed1986

[Importance of immunohistochemistry for neuro-oncology. IV. Distribution model of beta human chorionic gonadotropins in intracranial germ cell tumors].

beta-Human choriogonadotropic hormone (beta-HCG) is considered a good marker for trophoblastic differentiation of germ cell tumors. 34 primary intracranial germ cell tumors (15 germinomas, 6 mature teratomas, 1 embryonal carcinoma, 2 endodermal sinus tumors and 10 mixed germ cell tumors) were immunohistochemically evaluated for the presence of beta-HCG positive cells. In 8 of 15 germinomas and 6 of 10 mixed germ cell tumors beta-HCG cells were demonstrable. In the germinomas such cells included both syncytiotrophoblastic and mononuclear cells which histologically did not correspond to the cytotrophoblast. In one case the patient had exhibited a precocious puberty. Of the 6 beta-HCG positive mixed germ cell tumors, two contained elements of choriocarcinoma. In the cytotrophoblasts of the choriocarcinoma regions, beta-HCG was only sparsely demonstrable. Both of these patients had manifest precocious puberty clinically. The advantage of immunohistochemical demonstration of the beta-HCG compared to conventional histology is in the definite identification of trophoblastic differentiation, in particular the exact recognition of the choriocarcinoma segments, which can be critical for the prognosis. Demonstration of isolated syncytiotrophoblasts and beta-HCG positive mononuclear cells in the seminomas is of no prognostic significance and is primarily of theoretical interest.

Adolescent↗
PubMed1986

[Viral serology in ear diseases of presumably neuritic origin].

A viral etiology is often advanced to explain the origin of Bell's palsy, sudden deafness and certain vertigos. Virology findings were compared in 72 patients with either chicken pox, herpes, zona or other "viral" infections, where the viral origin was not absolutely clear, and a population of healthy volunteers. Results confirmed the indefinite viral nature of these affections. However, recent studies have shown that definite viral disorders are not always associated with an increase in antibody levels, and the intervention of a virus should not be totally discounted in some of these affections, especially as several particularly demonstrative cases have provided confirmation of a virus origin, particularly the Epstein-Barr virus.

Adult↗
PubMed1986

[2D-histograms of the nucleus area and nucleus shape in the diagnosis of astrocytomas and glioblastomas].

8 astrocytomas grade 1-4 and 2 glioblastomas were investigated by a system of automated microscope picture analysis. Histograms of nuclear area and shape from more than 1,000 measured nuclei per tumor were analysed. Both one- and two-dimensional histograms show findings which correlate with the malignant potential of the gliomas. The nuclear area rises with increasing tumor malignancy. On the other hand the measurements of nuclear shape factor are inversely related to the level of malignancy, indicating substantial irregularities in the nuclear structure. The 2D-histograms of both measured parameters also show changes which are correlated with the grade of tumor malignancy and which can be described as shift, loss of compactness and enlargement. The histogram method is discussed as an objectifiable process characterizing important cell and nuclear attributes connected with tumor malignancy. Histograms of both, nuclear area and shape can be helpful in the classification and grading of astrocytomas and glioblastomas.

Adult↗
PubMed1986

[Importance of immunohistochemistry for neuro-oncology. III. Demonstration of glial fibrillary acidic proteins (GFAP) in anaplastic astrocytomas and glioblastomas].

Expression of gliofibrillary acidic protein in 23 anaplastic astrocytomas and 33 glioblastomas has been investigated and correlated with tumor behavior as reflected in both the length of the preoperative history and in the post-operative survival time. Three degrees of positive immunoreactivity to anti-GFAP can be distinguished: positive GFAP reaction in more than 2/3 of cells; in 1/3 to 2/3 of all cells; in less than 1/3 of all cells; negative reaction. All anaplastic astrocytomas and 27 of 33 glioblastomas showed GFAP positive reactions. The proportion of highly reactive tumors is higher by anaplastic astrocytomas than by glioblastomas (7 of 33). For both astrocytomas and glioblastomas there is a tendency for a decrease in the expression of GFAP to be associated with a shorter preoperative history and with a shorter survival time. This is more prominent for astrocytomas than for glioblastomas. This finding supports the opinion expressed in previous publications that the GFAP expression is reversely related to the level of tumor anaplasticity.

Astrocytoma↗
PubMed1986

[Changes in telogen rate, hair density, hair diameter and rate of growth in androgenetic alopecia of the male. Simultaneously a contribution to the significance of dysplastic hair].

In a pilot study, comparative measurements of frontal and occipital trichograms, hair density, hair diameter and hair growth rate were performed on 26 male volunteers (ages 20-33 years) with androgenetic alopecia between stages II and V (Norwood scale). In the frontal region, the proportion of telogen hair was, in general, pathologically higher and increased according to stage. The density of the frontal hair was significantly lower (166 +/- 28/cm2) compared with that of the occipital region (193 +/- 24/cm2) and decreased according to stage. The average hair diameter in the higher Norwood stages decreased similarly in both the frontal and occipital regions, as shown by the correspondence between the two measurement points (frontal, 0.068 +/- 0.011 mm; occipital, 0.069 +/- 0.010 mm). Anagen and dysplastic hair from both the frontal and occipital regions was significantly thicker than telogen hair (0.07 mm vs 0.05 mm). The frontal growth rate (0.355 +/- 0.024 mm/day) was significantly lower than that of the occipital region (0.389 +/- 0.021 mm/day). In addition, the frontal growth rate decreased according to stage. Dysplastic hair exhibited high growth rates and diameters similar to those of typical anagen hair. In our opinion, dysplastic hair is growing hair, the roots of which have been artificially modified by plucking. - These intra-individual comparisons of frontal and occipital regions showed a reduction in the anagen phase, density, diameter and growth rate of the endangered frontal hair. A reduction in the size and dividing activity of the matrix is indicated by our data. It seems that these regressive changes occur primarily without a prior indication of accelerated hair growth.

Adult↗
PubMed1986

[Malignancy grading of glial tumors. II. Oligodendrogliomas].

Surgical biopsy material from 55 oligodendrogliomas was classified according to a four-level system of malignancy grading. Categorization was based on following criteria: numerical cell-density, cell and nuclear polymorphism, mitotic activity, proliferative activity of the vascular elements and degenerative phenomena, in particular necrosis. According to the intensity of these features, tumors were assigned to a malignancy level. The number of tumors alloted to each of the four ascending levels were 7, 15, 19, and 14, respectively with corresponding median survival times of 61.7, 27.7, 19.5, and 7.4 months. There was no statistically significant difference in the duration of survival between levels 2 and 3. The results of the investigation are consistent with reports from the literature which identify three prognostic grades for oligodendrogliomas, namely a group with low malignancy and a relatively good prognosis, an intermediate group and a group with a high level of malignancy and an extremely poor prognosis. It is suggested that the use of automated microscope image analysis or other quantitative methods contribute to more objective and reliable results.

Biopsy↗
PubMed1986

[Ankylosis of the malleus head. Etiology, therapeutic indications and results].

A review of 62 cases of blockage of head of malleus showed that apart from secondary lesions (post-traumatic, postoperative, postinfectious), primary blockades were a definite entity. The latter were either isolated or associated with stapedo-vestibular ankylosis. Isolated blockade of head of malleus provoties only direct transmission deafness, and is associated in nearly all cases with a cochlear lesion, often bilateral, at least in the primary forms. Instead of simple unblocking of the attic, the treatment preferred is an ablation of the incus, section of head of malleus and subsequent functional gestures that are described.

Adult↗
PubMed1986

[Trepanation of the labyrinth and congenital malformations].

Labyrinthine trepanation was performed in the majority of 16 patients with minor agenesis of middle ear involving either stapedovestibular ankylosis or absence of fenestra vestibuli. Preoperative findings are discussed, as well as the prevention and treatment of labyrinthine geysers and the possibility of obtaining a functioning labyrinthine opening. Results were good in simple cases but poorer in more complex lesions, for which the indication for use of this procedure is debatable.

Adolescent↗
PubMed1985

Effects of yohimbine on combined xylazine-ketamine-induced sedation and immobilization in juvenile African elephants.

Twenty-two juvenile African elephants were given a combination of xylazine (mean +/- SD = 0.14 +/- 0.03 mg/kg of body weight) and ketamine (1.14 +/- 0.21 mg/kg) as a single IM injection; one elephant was immobilized twice, 77 days apart. After injection, 14 elephants were immobilized, 4 were sedated deeply, 2 were sedated moderately, and 2 were sedated minimally. Immobilized elephants had a mean immobilization time of 11.6 +/- 6.9 minutes. At the conclusion of a variety of clinical procedures, 12 of the 14 elephants immobilized with a single dose combination of xylazine and ketamine were given yohimbine (0.13 +/- 0.03 mg/kg) IV, and the remaining 2 elephants were allowed to recover spontaneously; the elephants given yohimbine had a mean standing time of 2.4 +/- 1.1 minutes. Of the 8 sedated elephants, 5 were given an additional dose of combined xylazine (0.08 +/- 0.03 mg/kg), and ketamine (0.61 +/- 0.19 mg/kg) IM, and 1 elephant was given ketamine (0.47 mg/kg) IV. After injection, 4 of the 8 elephants were recumbent laterally within 17 minutes and 2 remained standing, under deep sedation. Seven of the 8 elephants were given yohimbine (0.13 +/- 0.03 mg/kg) IV; all were ambulatory in 2 minutes. Results indicated that yohimbine may be useful in controlling duration of xylazine-ketamine sedation and immobilization in juvenile African elephants.

Anesthesia, General↗
PubMed1985

[Endosurgery of subretinal strands in proliferative vitreoretinopathy].

Subretinal strands were removed in 9 patients with retinal detachment complicated by proliferative vitreoretinopathy (Stages C 2 to D 1). A small retinotomy was made in the area of the strand. The subretinal proliferative tissue was then drawn to the surface with forceps. In this way it was possible to remove all of the strands completely. One strand snapped while being drawn, thus necessitating a further incision. Two additional small retinectomies had to be performed because of firm attachments to the retina. In all cases retinal reattachment was achieved by silicone oil injection. No postoperative recurrences of the proliferations were observed. The follow-up period ranged from 2 to 9 months.

Adult↗
PubMed1985

The attitudes of nurse tutor students towards behavioural objectives: background and method of study.

Since behavioural objectives are rooted in behaviouristic psychology there is a brief discussion of some notable behaviourists. This is followed by reference to some key characters in the behavioural objectives movement. The strengths and weaknesses of behavioural objectives are discussed with reference to the relevant literature. Behavioural objectives in nursing education are considered and the tensions which their use may give rise to are noted. Finally, details are given of how a small-scale empirical study relating to behavioural objectives was conducted.

Attitude of Health Personnel↗