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Biomedical subjects

H Alexander

Publications and source records attributed to H Alexander.

At least 55 records · Page 3Linked to original sources
PubMed1998

The presence of chorionic gonadotrophin beta subunit in normal cyclic human endometrium.

The aim of the present study was to determine whether human endometrial cells are able to secrete beta-chorionic gonadotrophin (betaCG). Immunohistochemical studies and in-situ hybridization were performed in order to provide evidence for the occurrence of betaCG in the normal endometrium in 15 patients in the proliferative phase, two patients in the periovulatory phase and 13 patients in the secretory phase. Neither immunohistochemical nor hybridization reactions could be recognized during the proliferative phase. In contrast, both protein and betaCG mRNA were observed in the glandular cells of the endometrium during the secretory phase. The results were supported by Western blotting of secretory phase endometrium extracts and the assessment of the functional secretory capacity of primary endometrium cultures. In comparison with cultured and separated cell fractions, tissue extracts showed a higher betaCG, indicating a regulatory interaction. In conclusion, betaCG can be demonstrated in normal human cyclic endometrium, suggesting a paracrine role in endometrial physiology.

Cells, Cultured↗
PubMed1998

[Hugo Sellheim (1871-1936): Leipzig acknowledgement of gynecology].

In 1928 Hugo Sellheim, Professor and Chairman of gynaecology and obstetrics at the University of Leipzig (1926-1936), inaugurated the new Clinic of Gynaecology and Obstetrics. The opening ceremony found a critical public response. Although the new building had been drawn up by his predecessor Walter Stoeckel, Sellheim developed own ideas concerning the equipment of the institution. In Leipzig Sellheim is continued his scientific efforts with a story focus on female reproduction and its sociocultural impact during the period of the Weimar Republic.

Female↗
PubMed1998

Heterogeneity of noninvasive arrhythmic risk indicators in patients with ischemic cardiomyopathy.

Noninvasive electrocardiographic variables for arrhythmic risk stratification in chronic heart failure are of great clinical interest but remain highly controversial. This study analyzed repolarization dispersion, heart rate variability, ventricular ectopic activity, and hemodynamic parameters in 30 patients with ischemic heart failure and in 20 normal control subjects. The values for all parameters were distinctly separated between the failure and control group. Left ventricular ejection fraction had a strong relation to ventricular ectopic activity (r = .54), a weak association with repolarization dispersion (r = .29), and seemingly no parallels with heart rate variability (r = .12). However, no linear association could be detected between any of the arrhythmic risk indicators (r = .10-.22), whereas a number of linearly related angiographic-hemodynamic variables readily defined the mechanical risk profile. Thus, alterations of noninvasive arrhythmic risk indicators in heart failure are not uniform, which confounds approaches for a composite ECG risk score in individual patients.

Arrhythmias, Cardiac↗
PubMed1998

[Some aspects of the life work of Ludwig Fraenkel (1870-1951) with special reference to his social gynecology and sexology studies].

The gynaecologist Ludwig Fraenkel is known because of his works concerning the endocrine function of the corpus luteum. Moreover he was an important representative of the social gynaecology and sexology during the first decades of this century. His studies in these fields identify Fraenkel as an independent scientist considering for example social living conditions as a cause of gynaecological illnesses. On the other hand he took over problematic positions in eugenics hoping to improve public health. During the Hitler era the Jew Ludwig Fraenkel was dismissed from the directorate of the Women's clinic of the University of Breslau. He left Germany forever.

Germany↗
PubMed1997

Synthetic strategies for the preparation of precursor polymers and of microcapsules suitable for cellular entrapment by polyelectrolyte complexation of those polymers.

The production of microcapsules suitable for the entrapment of mammalian cell by means of polyelectrolyte complexation has, of a necessity, led to the development of novel strategies for the preparation of relatively bioinert polymers which complex efficiently under unique conditions to produce a mechanically resilient membrane with efficient transport properties. In this communication we relate a brief overview of capsule-membrane forming systems for the immunoisolation (or potential immunoisolation) of mammalian cells, which are based upon the complexation of polyelectrolyte (PE) polymers; with emphasis on precursor synthesis and relationships between precursor polymer structure and capsule membrane stability.

Animals↗
PubMed1997

The Dictyostelium discoideum beta-1,4-mannosyltransferase gene, mntA, has two periods of developmental expression.

The precise roles of protein glycosylation in multicellular development are poorly understood. We have characterized the mntA gene from Dictyostelium discoideum which encodes the beta-1,4-mannosyltransferase enzyme that catalyzes the reaction: GDP-Man + dolichol-PP-GlcNAc2 --> dolichol-PP-GlcNAc2-Man + GDP. This gene has a central role in the synthesis of the lipid-linked oligosaccharide precursor which becomes the core of all asparagine-linked (N-linked) glycans. The mntA gene contains a single small intron and encodes a 493 aa protein with a predicted molecular size of 56 kDa. It is located 5' to the repE gene on chromosome IV and is transcribed in the opposite orientation to repE with which it shares a 585 bp of upstream intergenic region. The predicted mntA gene product shares 38% homology with the S. cerevisiae ALG1 gene product. The MntA protein has a region homologous to the putative dolichol-binding region in the yeast ALG1 protein, but it is located in a different part of the molecule. Northern analysis revealed that the expression of the mntA gene is regulated during multicellular development with two periods of mRNA accumulation. The mntA gene product has a classical endoplasmic reticulum retention motif, and is the first Dictyostelium gene encoding a protein that is active in this organelle. The identification of this gene will allow expanded studies of the role of N-linked glycans in multicellular development.

Amino Acid Sequence↗
PubMed1997

Differential developmental expression of the rep B and rep D xeroderma pigmentosum related DNA helicase genes from Dictyostelium discoideum.

DNA helicases are essential to many cellular processes including recombination, replication and transcription, and some helicases function in multiple processes. The helicases encoded by the Xeroderma pigmentosum (XP) B and D genes function in both nucleotide excision repair and transcription initiation. Mutations that affect the repair function of these proteins result in XP while mutations affecting transcription result in neurological and developmental abnormalities, although the underlying molecular and cellular basis for these phenotypes is not well understood. To better understand the developmental roles of these genes, we have now identified and characterized the rep B and rep D genes from the cellular slime mold Dictyostelium discoideum . Both genes encode DNA helicases of the SF2 superfamily of helicases. The rep D gene contains no introns and the rep B gene contains only one intron, which makes their genomic structures dramatically different from the corresponding genes in mammals and fish. However the predicted Dictyostelium proteins share high homology with the human XPB and XPD proteins. The single copy of the rep B and D genes map to chromosomes 3 and 1, respectively. The expression of rep B and D (and the previously isolated rep E) genes during multicellular development was examined, and it was determined that each rep gene has a unique pattern of expression, consistent with the idea that they have specific roles in development. The pattern and extent of expression of these genes was not affected by the growth history of the cells, implying that the expression of these genes is tightly regulated by the developmental program. The expression of the rep genes is a very early step in development and may well represent a key event in the initiation of development in this organism.

Amino Acid Sequence↗
PubMed1997

[Endomyocardial biopsy--helpful in differential diagnosis between myocarditis and dilated cardiomyopathy. A case report].

Endomyocardial biopsy is an established technique to distinguish between myocarditis and dilated cardiomyopathy. Even when clinical symptoms for myocarditis are lacking, immunohistologic findings may establish a clear diagnosis. For treatment, however, an early diagnosis is mandatory. We report on a 44 year old patient who was admitted with the echocardiographic diagnosis of dilated cardiomyopathy. He underwent diagnostic angiocardiography and endomyocardial biopsy. The latter demonstrated an active myocarditis. At the time of read-mission, 2 weeks later, the patient had deteriorated. Now, additional to a symptomatic therapy, prednisolone, azathioprine and human immunoglobulin G were given and patient conditions improved dramatically. The use of endomyocardial biopsy seems recommendable in order to define patients diagnosis and their results may be necessary to decide patients therapy.

Adult↗
PubMed1997

Protein denaturation induced by cyclic silicone.

While it has been demonstrated that such low-molecular-weight cyclic silicones as octamethylcyclotetrasiloxane (D4) exhibit adjuvant activity, the mechanism of immunological response to silicone is still not clear. This study therefore used fluorescence and circular dichroism (CD) spectroscopy to investigate the denaturation and conformational change of two proteins, fibronectin (Fn) and fibrinogen (Fbg), induced by D4 in vitro. Incubating D4 with Fbg or Fn at D4-to-protein ratios of > 100 or for > 10 h yielded white and mould-like precipitates of the proteins, indicating massive denaturation and aggregation. The fact that the decrease in fluorescence intensity of D4-treated Fn and Fbg was accompanied by a red shift in the maximum wavelength also indicated that denaturation of the proteins had taken place. These changes in fluorescence might result from exposure of tryptophan residuals in the proteins to polar water molecules inasmuch as the denaturation would lead to changes in the tertiary structures of the proteins and rearrangement of the tryptophan residues. The loss of the tertiary structure leads to protein denaturation and, consequently, precipitation. The difference in CD spectra between control Fbg (or Fn) and D4-treated Fbg (or Fn) indicated conformational changes of the proteins when incubated with D4. Thus it has been demonstrated that D4 can induce denaturation and conformational changes in Fbg and Fn and it can be expected that protein molecules that have undergone denaturation or conformational change induced by D4 may act as antigens and stimulate the immune system to generate antibodies, ultimately resulting in autoimmune disease.

Adjuvants, Immunologic↗
PubMed1997

Dietary trends: estimates from food supply and survey data.

OBJECTIVE: To illustrate methodological issues involved in estimating dietary trends in populations using data obtained from various sources in Australia in the 1980s and 1990s. METHODS: Estimates of absolute and relative change in consumption of selected food items were calculated using national data published annually on the national food supply for 1982-83 to 1992-93 and responses to food frequency questions in two population based risk factor surveys in 1983 and 1994 in the Hunter Region of New South Wales, Australia. The validity of estimated food quantities obtained from these inexpensive sources at the beginning of the period was assessed by comparison with data from a national dietary survey conducted in 1983 using 24 h recall. RESULTS: Trend estimates from the food supply data and risk factor survey data were in good agreement for increases in consumption of fresh fruit, vegetables and breakfast food and decreases in butter, margarine, sugar and alcohol. Estimates for trends in milk, eggs and bread consumption, however, were inconsistent. CONCLUSIONS: Both data sources can be used for monitoring progress towards national nutrition goals based on selected food items provided that some limitations are recognized. While data collection methods should be consistent over time they also need to allow for changes in the food supply (for example the introduction of new varieties such as low-fat dairy products). From time to time the trends derived from these inexpensive data sources should be compared with data derived from more detailed and quantitative estimates of dietary intake.

Adult↗
PubMed1997

A study of errors that can occur when weighing infants.

When infants are weighed at well baby or infant welfare clinics, the weight change from one visit to the next is used as a guide to the welfare of the child. Infant welfare clinic nurses are expert clinicians who use weight measurements as a rough indicator of well-being only, as it is well known by them that these measurements are fraught with error. This paper calculates the amount of error which was found in repeated tests of weights of infants, and in the weight changes brought about by biological variation. As a result, it is recommended that babies under nine months of age be weighed at clinic visits no less than a fortnight apart, and older infants, at least one month apart. If they are weighed more often, then the weight changes detected will be less than the amount of error which affects the measurements.

Anthropometry↗
PubMed1997

Effects of intra-aortic balloon occlusion on hemodynamics during, and survival after cardiopulmonary resuscitation in dogs.

OBJECTIVE: To evaluate the effect of balloon occlusion of the proximal descending aorta during cardiopulmonary resuscitation (CPR) on hemodynamics, restoration of spontaneous circulation, and 24-hr survival. DESIGN: Prospective, randomized, controlled trial. SETTING: Experimental laboratory in a university hospital. SUBJECTS: Eighteen anesthetized dogs. INTERVENTIONS; Catheters were placed for hemodynamic and blood gas monitoring. An aortic balloon catheter was placed with its tip just distal to the left subclavian artery. After 10 mins of ventricular fibrillation without CPR, 3 mins of Basic Life Support (chest compressions and ventilation with 100% oxygen) was followed by up to 30 mins of Advanced Cardiac Life Support with canine drug dosages. In the treatment group (n = 8), the intra-aortic balloon was inflated when Advanced Cardiac Life Support started and not deflated until shortly after restoration of spontaneous circulation. The control animals (n = 10) were treated with an identical resuscitation but without intra-aortic balloon occlusion. MEASUREMENTS AND MAIN RESULTS: In the treatment group, coronary perfusion pressure was greater during Advanced Cardiac Life Support (p = .026). Restoration of spontaneous circulation was more frequent (7/8 dogs) as compared with the control group (3/10 dogs) (p = .025). There was a trend toward greater 24-hr survival in the treatment group (5/8 dogs) than in the control group (3/10 dogs). CONCLUSIONS: Balloon occlusion of the proximal descending aorta during experimental CPR improves restoration of spontaneous circulation. Further laboratory and human studies are needed to determine the clinical efficacy of this technique.

Animals↗
PubMed1997

Whose diet has changed?

The same questions about diet were asked in two community-based surveys conducted in the Hunter Region of New South Wales in 1983 and 1994. There were substantial changes in diet over the period; for example, the proportion of respondents who reported using low-fat or skim milk increased from 25 per cent to 51 per cent, the proportion eating meat fewer than five times a week doubled from 21 per cent to 42 per cent and the proportion eating fewer than three eggs per week increased from 55 per cent to 80 per cent. In both surveys, women reported eating a healthier diet than men, and older people and those of higher socioeconomic status reported better diets than younger people or people with less education or lower status occupations. The surprising finding was that over the 11-year period the changes in patterns of food consumption were remarkably similar across all strata of the population. The conclusions are that wide-spread dietary change is possible. However, the changes in the last decade related mainly to reducing the risk of cardiovascular disease; similar behavioural changes to reduce the risk of diet-related cancer are required.

Adult↗
PubMed1997

[Cervical pregnancy: case report and review of the literature].

We report on a 22 years old patient with an intact cervical pregnancy located around the cervical isthmus in the 9th week of gestation. Because of the patients strong desire to maintain the reproductive capability, we performed a transvaginal amniotic sac puncture with local application of methotrexate. Later on we applied a systemic methotrexate therapy because of persistent high serum beta-hCG values. Five weeks later the patients developed heavy vaginal bleeding despite low beta-hCG levels so we are obliged to perform vaginal hysterectomy. Actual aspects about the etiology and diagnosis of this rare disease as well as about different opinions regarding conservative, fertility maintaining therapies are discussed.

Adult↗
PubMed1997

[Immunohistochemical evidence of immuno-reactive hCG in the secretory endometrium in women].

The endometrium is a highly differentiated hormone dependent tissue. Its function is to make an implantation and pregnancy possible. The present study was carried out to investigate whether human endometrial cells are able to produce immune reactivity like hCG (ir-hCG). Immunohistochemical examinations of the endometrium were performed in 15 patients in the proliferative phase, 2 patients in the peri-ovulatory phase and 13 patients in the secretory phase. Immunohistochemical investigations of placenta from women who had an artificial abortion were used as controls. No immunohistochemical reaction in the endometrium could be recognized during the proliferative phase. In contrast a clear reaction was observed in the cells of the epithelium of the endometrium during the secretory phase. At the beginning of the secretory phase the ir-hCG was detected to be in the basal subnuclear region. In the middle of the secretory phase ir-hCG was found in the apical supranuclear region and later on in the glands. In the stroma of the endometrium single immunohistochemical positive cells could be seen. The function of the ir-hCG of the endometrium should be elucidated.

Adult↗