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Biomedical subjects

R Guggenheim

Publications and source records attributed to R Guggenheim.

At least 19 recordsLinked to original sources
PubMed2006

Bone marrow transplantation for cartilage-hair-hypoplasia.

The association of cartilage hair hypoplasia (CHH) with severe combined immunodeficiency (SCID) has been known for more than three decades. Bone marrow transplantation (BMT) remains the only effective treatment that might cure SCID. Surprisingly little has been reported on the experience with BMT in CHH. We report here survival and long-term reconstitution of immunity after BMT in three patients with CHH. Regardless of whether a related human leukocyte antigen-matched or unrelated matched donors were used as the source of BMT, all patients are alive and well 5-20 years after BMT. Engraftment appears robust with most cells of donors origin. Repeated evaluation of the immune system showed normal cellular and humoral immunity. Our results should encourage the use of BMT in patients with CHH who have profound immunodeficiency.

Bone Marrow Transplantation↗
PubMed2000

Characterization of an immortalized human granulosa cell line (COV434).

We have investigated the biological characteristics of an immortalized granulosa cell line (COV434), which may be used to study follicular and oocyte maturation in vitro. Granulosa cell function was defined as consisting of three distinct properties: (i) production of 17beta-oestradiol in response to follicle stimulating hormone (FSH); (ii) presence of specific molecular markers of apoptosis enabling the induction of follicular atresia; and (iii) capacity to form intercellular connections with cells surrounding an oocyte. The addition of FSH to the culture medium supplemented with 10% fetal calf serum and 4-androstene-3,17-dione resulted in proliferation of the COV434 granulosa cells and in an increased synthesis of 17beta-oestradiol, indicating the presence of the FSH receptor and cytochrome P450 aromatase in these cells. The receptor for luteinizing hormone (LH) was undetectable. Similar expression of various apoptosis-associated genes was found in COV434 granulosa cells and in granulosa cells of patients stimulated with gonadotrophins for in-vitro fertilization, thus indicating that the immortalized COV434 granulosa cells were able to sustain apoptosis. Multiple intercellular connections were formed during co-culture of COV434 granulosa cells with cumulus cells containing an immature oocyte but not with cumulus cells devoid of an oocyte. Detailed morphological analysis of the intercellular connections with scanning electron microscopy and confocal light microscopy demonstrated the presence of long slender structures. It is concluded that the immortalized human granulosa cell line COV434 may be useful for experimental studies on follicular development.

Apoptosis↗
PubMed1999

PR-1 protein inhibits the differentiation of rust infection hyphae in leaves of acquired resistant broad bean.

Treatment of broad bean leaves with salicylic acid (SA) or 2, 6-dichloro-isonicotinic acid (DCINA) induces resistance against the rust fungus Uromyces fabae resulting in reduced rust pustule density. Light-microscopy studies showed that in induced resistant plants the rust fungus is inhibited immediately after penetration through the stomatal pore. The differentiation of infection structures growing within the intercellular space of the leaf, i.e. infection hyphae and haustorial mother cells, is inhibited. Furthermore, low-temperature scanning electron microscopy studies of freeze fractures revealed protrusions at the tips of infection hyphae growing in induced resistant broad bean leaves. Treatment of in vitro-differentiating rust infection structures with intercellular fluids (IFs) from induced resistant plants confirmed that the fungus is sensitive towards an apoplastic anti-fungal activity only after having formed appressoria. Other legume rusts such as U. vignae and U. appendiculatus were likewise inhibited in the presence of IF from SA-treated broad bean leaves. Heterologous antibodies were used to study changes in the extracellular pathogenesis-related (PR) protein pattern after resistance induction. Western blots indicated that chitinases and beta-1,3-glucanases were present in both induced and control plants. In contrast, PR-1 proteins were newly synthesized in response to SA or DCINA application. The major induced PR-1 protein was purified and exhibited strong differentiation-inhibiting activity towards U. fabae infection structures. We conclude that the inhibition of rust infection hyphae in acquired resistant broad bean plants is mainly due to the anti-fungal activity of this induced basic PR-1 protein.

Antifungal Agents↗
PubMed1996

Trichorhinophalangeal syndrome type III.

Trichorhinophalangeal syndrome (TRPS) type III is a newly defined clinical entity. This symptom complex is inherited as an autosomal dominant trait and clinically characterized by growth retardation, craniofacial abnormalities, severe brachydactyly and sparse hair. In addition, absence of mental retardation and cartilaginous exostoses are required for the diagnosis of TRPS III. To further delineate this newly recognized entity, we report on a patient from a Turkish family segregating TRPS III in 7 family members. The patient had a very short stature (147 cm, < 3rd standard deviation), a thin upper lip and a prominent lower lip, a pear-shaped nose, stubby fingers and toes with cone-shaped epiphyses and sparse scalp hair. Scanning electron microscopy findings and results of energy-dispersive X-ray microanalysis are presented in such a patient for the first time.

Abnormalities, Multiple↗
PubMed1995

[Hair-like hyperkeratoses in patients with kidney transplants. A new cyclosporin side-effect].

We report a 31-year-old renal transplant patient treated with cyclosporin A who developed an unusual sebaceous gland hyperplasia accompanied by a disseminated follicular spiny hyperkeratosis. Those alterations were most evident on his face and limbs. In some locations hairy hyperkeratosis with authentic hair neogenesis was found. The histology of these alterations showed a marked hyperkeratosis of the hair follicles with formation of hair-like spikes either alone or in connection with hairs. The presence of true hairs distinguishes our case from the morphologically similar disseminated spiked hyperkeratosis and other spiny keratinization disorders. Scanning electron microscopy helped to demonstrate the hair-like structure of these keratoses. Some of the sebaceous glands showed cystic widening of their lumina, which were filled with abundant amorphous eosinophilic material, a finding similar to earlier observations. Our case demonstrates that these skin alterations should be classified as side effects of cyclosporin A and that they are apparently dose-dependent.

Adult↗
PubMed1994

A new clinical disorder of twisted and rolled body hairs with multiple, large knots.

BACKGROUND: We present a new hair disorder characterized by an unusual twisting and matting of body hairs. This disorder may occur as an acquired or, possibly, an inherited trait. OBJECTIVE: Our purpose was to analyze the clinical features of three patients and report the changes revealed by light microscopy and scanning electron microscopy. METHODS: We examined two unrelated adults with acquired multiple large knots of body hairs and a newborn infant with a familial history of the same entity. RESULTS: In the two adults the hairs were rolled and knotted together, and twisting of body hairs occurred in areas where rubbing was frequent. In the familial type, which was suggestive of an autosomal dominant inheritance pattern, no mechanical explanation could be found. Light microscopy confirmed the clinical impression of twisted and felted hairs, and scanning electron microscopy revealed sticking of at least 20 hairs. No underlying skin disease or deeper process was found. CONCLUSION: Multiple twisted and rolled body hairs that may develop into multiple, large knots may appear as a minor variant of hair matting or felting. Scanning electron microscopy shows multiple hairs that originate from different hair follicles and roll and stick together centrally.

Aged↗
PubMed1993

Effectiveness of open flap root debridement with rubber cups, interdental plastic tips and prophy paste. An SEM study.

This study was designed to ascertain whether conservative cleaning of surgically-exposed root surfaces can achieve complete plaque removal. 10 single-rooted teeth (40 surfaces) from 4 patients with advanced periodontitis were included in the study. After flap reflection, the root surfaces were cleaned using only rubber cups, EVA plastic tips and prophy paste. No attempt was made to remove calculus. Immediately after treatment, the teeth were extracted. Then root surfaces were systematically examined in the scanning electron microscope to detect any residual bacteria (plaque). 27 of the 40 treated root surfaces were plaque-free. On the other 13 root surfaces, only a few isolated small islands of plaque were detected. On the other hand, relatively extensive areas of the root surfaces exhibited calculus. Bacterial plaque accumulation was routinely observed on the rough calculus surfaces and at the periphery of the hard deposits. These results demonstrate that the instruments used in this study can successfully remove plaque from exposed root surfaces. However, subgingival calculus that is firmly attached to root surfaces virtually always harbors plaque bacteria; such deposits require more aggressive instrumentation (scalers, curettes) for removal.

Adult↗
PubMed1993

Pili trianguli et canaliculi: a distinctive hair shaft defect leading to uncombable hair.

Uncombable hair syndrome refers to a clinical disorder characterized by scalp hairs arranged in bundles in all directions that resist to brush and comb. Several entities may lead to spun-glass hair. As a rule the syndrome becomes obvious during the first years of life. The hair is normal in quantity, and increased fragility is not a common feature. The hair is often dry with silvery blond color. Under the light microscope the hairs may appear normal. Scanning electron microscopy shows a characteristic triangular, kidney- or heat-shaped diameter with typical longitudinal canalicular deformation. We present a 9-year-old girl with the typical clinical features of pili trianguli et canaliculi. Investigation by scanning electron microscopy confirmed the diagnosis. In addition the girl had enamel defects of the teeth and nail abnormalities that classify for a subtype of ectodermal dysplasia.

Child↗
PubMed1992

Non-surgical periodontal treatment: where are the limits? An SEM study.

In the present scanning electron microscopic study, the possibilities and limitations of non-surgical root planing were investigated. 10 single-rooted teeth from 4 patients with advanced periodontitis were studied. The root surfaces were cleaned and planed without flap reflection, using fine curettes. The teeth were then extracted and the root surfaces were systematically examined by scanning electron microscopy (SEM) for the presence of residual bacteria and calculus. 29 of 40 curetted root surfaces were free of residues, if they were reached by the curette. On the remaining 11 surfaces, only small amounts of plaque and minute islands of calculus were detected, primarily at the line angles and also in grooves and depressions in the root surfaces. Instrumentation to the base of the pocket was not achieved completely on 75% of the treated root surfaces, however. The primary reason for this was the extremely tortous pocket morphology on the teeth selected for study. In conclusion, it may be stated that during non-surgical root planing in cases of advanced periodontitis, surfaces that can be reached by curettes are usually free of plaque and calculus. However, in many cases the base of the pocket will not be reached. It is for this reason that deep periodontal pockets should be treated with direct vision, i.e., after the reflection of conservative flaps.

Adult↗
PubMed1991

Coronin, an actin binding protein of Dictyostelium discoideum localized to cell surface projections, has sequence similarities to G protein beta subunits.

A soluble actin binding protein of Dictyostelium discoideum cells has been extracted and purified from precipitated actin-myosin complexes. This protein with a relative molecular mass of 55 kDa has been named coronin because of its association with crown-shaped cell surface projections of growth-phase D. discoideum cells. In aggregating cells, which respond most sensitively to the chemoattractant cyclic AMP, coronin is accumulated at the front where surface projections are directed towards a cAMP source. Since these cells can quickly change shape and polarity, it follows that coronin is rapidly reshuffled within the cells during motion and chemotactic orientation. The cDNA derived sequence of coronin indicates a protein of 49 kDa, consisting of an amino-terminal domain with similarities to the beta subunits of G proteins and a carboxy-terminal domain with a high tendency for alpha-helical structure. It is hypothesized that coronin is implicated in the transmission of chemotactic signals from cAMP receptors in the plasma membrane through G proteins to the cortical cytoskeleton, whose structure and activity is locally modulated.

Amino Acid Sequence↗
PubMed1991

[In-vitro research on the precision of the marginal adaptation of computer-milled titanium crowns (I). Scanning electron microscopy marginal fissure analysis].

The Digitising Computer System (DCS) can be mechanically programmed to produce computer-milled titanium frameworks for veneered ceramic single crowns using three-dimensional computer models. Titanium frameworks were constructed in this way during the present in-vitro investigation involving twelve extracted teeth with shoulder or chamfered preparation. An electron scanning microscope was used to evaluate the marginal accuracy of fit of the cemented crowns. The total length of 42.7 cm comprised by the crowns enabled 397 measuring points to be used. The arithmetical mean marginal leakage for the shoulder preparation amounted to 68.3 +/- 61.1 micrometers, and 95.7 +/- 83.2 micrometers for the chamfered one. From these results, it can be affirmed that the marginal accuracy of fit in constructing crowns by the Digitising Computer System is comparable to that of the conventional method.

Computer Graphics↗
PubMed1989

The effectiveness of root debridement in open flap procedures by means of a comparison between hand instruments and diamond burs. A SEM study.

The goal of the present in vivo study was to evaluate human roots by means of scanning electron microscopy (SEM), after treating the root surfaces either with conventional hand instruments or with newly developed diamond burs. Peculiar root anatomy often makes perfect instrumentation with hand instruments difficult or impossible. On 20 teeth destined for extraction because of severe periodontitis, the root surfaces were exposed by mucoperiosteal flap procedures. Ten roots were then planed using fine curettes, and 10 were instrumented using diamond burs. Following extraction, the root surfaces were stained and photographed. Stained areas were examined by SEM. On the 20 test teeth, 79 surfaces were evaluated. From these, 381 stained zones were checked by SEM for the presence of bacteria. A total of 216 stained areas from teeth treated by hand instruments was evaluated; 15 of these (6.9%) contained bacteria. Of roots treated by diamond burs, 165 stained areas were evaluated; 9 (5.5%) exhibited bacteria. Thus, both methods resulted in root surfaces that were essentially bacteria-free.

Adult↗
PubMed1983

Crystallized hemoglobin in Rhodnius prolixus after a blood meal on guinea-pig.

Several blood-sucking arthropods, after a blood meal, are able to store the hemoglobin from their hosts in a crystalline state in their digestive system. Guinea-pig hemoglobin crystallizes in the stomach of the reduviid bug Rhodnius prolixus in two different crystal types. We show them to be crystallographically identical and to contain the same liganded state of hemoglobin, i.e. they represent different habits of the same crystal modification. The hemoglobin crystallizes in oxy-form and ages in the crystalline state, first to aquomethemoglobin and subsequently to hemichrome without crystal cracking. The rate of aging appears to be the same for both types. The hemoglobin crystal modification observed in the digestive system of Rhodnius prolixus is highly host- but not parasite- specific. The same modification is also observed in vitro and in Ornithodorus moubata, an arachnid whose digestive system differs considerably from that of the insect Rhodnius. The retainment period of the crystals represents a long term host-record of possible medical interest.

Animals↗
PubMed1983

[Albumin receptors on isolated human hepatocytes. Studies by phase contrast and scanning electron microscopy].

In the present work a minibead method has been employed to study human hepatocyte receptors for albumin-coupled latex particles. The cell-latex reaction was observed in both phase contrast and scanning electron microscopy. It has been demonstrated that human hepatocytes exhibit bindings sites for different forms of glutaraldehyde-treated albumin, and the ligand has proved to be species-nonspecific. The albumin binding activity is temperature-dependent and can be only partially blocked by preincubation with free, glutaraldehyde-treated protein, unless hepatocytes are pretreated with vinblastine sulfate. The possible biological role of these receptors as regards the infection due to the hepatitis B virus (that shares common, but not identical binding sites) is also discussed.

Humans↗
PubMed1982

[Cogan-Reese syndrome].

The clinical, histological and ultrastructural findings in a case of Cogan-Reese syndrome (iris nevus) are presented. The typical iris nodules first appeared 14 years after a unilateral, juvenile, open-angle glaucoma was diagnosed. No lasting regulation of the intermittently elevated pressure was possible either medically or surgically. The failure of two filtering operations was due to the histologically verified endothelialization of the blebs. Endothelialization and deposition of Descemet's membrane on the anterior surface of the lens and on the zonule is described for the first time in this syndrome. The histological findings support the view that the peripheral anterior synechiae and iris nodules are secondary to the endothelialization. Hence the diagnosis of Cogan-Reese syndrome cannot be made until relatively late in the course of this disease. Cytological similarities between the proliferating endothelium in this case and in Chandler syndrome support the recent hypothesis that the Cogan-Reese syndrome belongs to the irido-corneal-endothelial group of syndromes.

Adult↗