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Biomedical subjects

G Walther

Publications and source records attributed to G Walther.

At least 19 recordsLinked to original sources
PubMed1994

[Cell therapy and its risks].

Parenteral administration of fresh cells, frozen cells (snapfrozen cell suspensions) or lyophilized cells (sicca cells), is known as cellular or cell therapy. While the German Health Office (BGA) provisionally banned the use of dried cell preparations in 1987, injection of fresh cells is still allowed. There have been repeated reports of life-threatening, and even fatal, complications of this type of therapy. Since it involves the administration of heterologous biological material, most of the complications that have been observed have been of the allergic/hyperergic type resembling experimental allergic encephalomyelitis (EAE) and experimental allergic neuritis (EAN). When evaluating the risks of this form of alternative-medical treatment, the well-known risks of injection therapy must also be borne in mind. In the case of cell therapy, too, the hoped for effect must be weighed against the risks of the procedure, and our guiding principle must be: nil nocere.

Cell- and Tissue-Based Therapy↗
PubMed1993

WAL 2014--a muscarinic agonist with preferential neuron-stimulating properties.

The ability of WAL 2014 to elicit muscarinic responses was investigated in various in vitro and in vivo models. In CHO cells transfected with human m1- or m3- receptor genes, WAL 2014 was clearly more effective in stimulating the M1-mediated PI response. In isolated tissue preparations, WAL 2014 exhibited full agonist properties in the rabbit vas deferens (putative M1 receptor) and behaved like a partial agonist at M2 receptors in the atrium and M3 receptors in the ileum of guinea-pigs. In the pithed rat, in which the increase in blood pressure is mediated through a stimulation of M1 receptors in sympathetic ganglia, WAL 2014 produced a full dose response curve, whereas the reference compounds RS 86 and arecoline exhibited a bell-shaped behaviour. This is in accord with the view that WAL 2014 selectively activates M1 receptors in sympathetic ganglia, whereas conventional agonists in the same dose range stimulate both ganglionic M1 and vascular M3 receptors. The preferential neuron-stimulating properties were confirmed by EEG recording in the rabbit, in which muscarinic activation occurred at doses similar to those for ganglionic stimulation in the pithed rat. On the other hand, higher doses of WAL 2014 were needed to elicit muscarinic effects in peripheral effector organs, i.e. bradycardia, urinary bladder contraction and increase in airway resistance. It is concluded that WAL 2014 due to its preferential neuronal activity is a promising candidate for a cholinergic substitution therapy in Alzheimer's disease.

Animals↗
PubMed1990

New tetracyclic guanidine derivatives with H1-antihistaminic properties. Chemistry of epinastine.

A series of new tetracyclic guanidines were synthesized by various methods. Specific binding of the described compounds to histamine-1 and histamine-2 receptors was determined. The compound 3-amino-9,13b-dihydro-1H-dibenz[c,flimidazo[1,5-a]azepine (epinastine, WAL 801, compound IIIa) combines high selectivity with high affinity for the H1 receptor and was selected from the compounds studied for further pharmacological and clinical investigations. Experimentally determined physicochemical parameters (pka-value, partition coefficient) and the hydrogen-bonding ability of epinastine are indications that this compound will not easily cross the blood-brain barrier. This explains the absence of CNS side-effects of epinastine in pharmacological and clinical studies.

Animals↗
PubMed1990

[Effect of Cyclosporin-A on gingiva].

Cyclosporin-A is a new immunosuppressive agent which has been used successfully to prevent organ rejection. Gingival overgrowth is one side-effect of the drug which is of interest for the dentist. The pathogenesis of the gingival alteration is unknown, but the dental plaque is discussed as a co-destructive factor.

Cyclosporins↗
PubMed1989

[Complications following cell therapy].

So far, the law in the Federal Republic of Germany still allows the injection of fresh-cell preparations from animals as a roborant to increase the vitality of the organism and to strengthen the body's immune defense system. The use of "sicca-cell" preparations was provisionally forbidden in 1987 by the Federal Health Organization (Bundesgesundheitsamt; BGA). Prohibition of fresh-cell injections would have exceeded the authority of this office, although the same serious reservations also applied in the case of this treatment method. Several publications that have appeared since 1955 have reported serious complications of this therapy, some life-threatening and some even lethal. Two further cases are now added: (1) A woman aged 69 had been receiving treatment with cell injections for 9 years. Immediately after an injection of sicca cells she collapsed and was hospitalized; 7 days thereafter she developed an ascending paralysis with increasing inability to swallow or breathe. She died 25 days after the injection as a consequence of central and peripheral respiratory failure. Autopsy revealed the alterations typical for acute Landry-Guillain-Barré-Strohl syndrome. (2) A 76-year-old healthy woman had been receiving treatment with fresh-cell preparations for several years. After an injection of cell suspensions a painful local swelling was observed. The symptoms were interpreted as the consequence of an iatrogenic local hematoma, and repeated punctures were performed to obtain blood. The patient was transferred to a surgical department for further therapy. Two days after the injection she suddenly died with signs of acute cardiovascular failure. Autopsy revealed the signs of a fulminating clostridial infection and also the characteristic signs of Landry-Guillain-Barré syndrome with involvement of the autonomic nervous system. In both cases the development of an inflammatory process in the peripheral nervous system could be interpreted as an immune-mediated allergic disease, related to the repeated injection of heterologous antigenic material containing nervous tissues. This hypothesis would also explain the two other cases already published and would be consistent with the observed perivenous leukoencephalopathy of the central nervous system. The human disease pictures correspond to the well-established animal models of EAEM (experimental allergic encephalomyelitis) and EAN (experimental allergic neuritis). The pathogenesis is discussed; the major role of the central and peripheral nervous system is stressed, with special reference to the risk of acute autonomic failure. The need for specific autopsy techniques for the investigation of the entire nervous system, including spinal cord, roots, spinal ganglia and peripheral nerves with sympathetic chains, is raised.

Adult↗
PubMed1989

[Caries decline and changing pattern of dental therapy].

The most striking feature of some industrialized countries is a dramatic reduction of the prevalence of dental caries among school-aged children. As a result, teeth are being retained longer than before and it is possible that the incidence of caries--especially root caries--is increasing. It is an error of judgement that dentistry becomes simplier. With the increase of life span there will be an increase of needs for restorative dentistry in the older age groups of the population. The dentist of the future has to be a flexible practitioner who has had a broader based education.

Dental Care↗
PubMed1988

A sex cord stromal tumour in a woman with XO/XX/XXX-mosaicism.

We describe a postmenopausal woman with 45,XO/46,XX/47,XXX mosaicism who presented with a Sertoli-Leydig cell tumour and a past history of habitual abortion. The cytogenetic finding is discussed in relation to the etiology of the tumour and of the recurrent abortions.

Female↗
PubMed1987

Fetus with asymmetric parietal encephalocele, and hydrops secondary to laryngeal atresia.

We describe a fetus with an asymmetric, nonmidline, parietal encephalocele that appeared to result from "expulsion" through the center of the membranous bone; the fetus also had laryngeal atresia, which caused pulmonary overdistension (fetal Valsalva maneuver) with consequent hydrops fetalis. A common cause and clear pathogenetic relationship between these anomalies is not apparent.

Abnormalities, Multiple↗
PubMed1986

Early receptor potential recordings for clinical routine.

An apparatus and an electrode for early receptor potential recordings in clinical routine are introduced. One-hundred and eighty normal eyes were compared with cases of diffuse and localized retinal diseases. In retinitis pigmentosa patients a decrease in R1 and R2 amplitudes and in some cases a much faster time course was found. Eyes with circumscribed retinal affectations produced a wide variety of amplitudes, overlapping with the range of normals. In cases of monochromatism, the ERP recording established the diagnosis because of an absent R1 wave.

Electrophysiology↗
PubMed1986

Fresh cell therapy followed by fatal coma.

A 60-year-old woman received a 3-day course of nine injections of "fresh" cells from fetal lamb ovary, placenta, brain (hypothalamus) and liver. There were no immediate complications, but a few days later she developed headache, fever and hemiparesis. She subsequently fell into a coma and died 3 weeks after her fresh cell therapy and 2 weeks after the onset of her clinical symptoms. Autopsy revealed perivenous leucoencephalopathy with a probably steroid-treatment-induced paucity of perivascular inflammation. Fresh cell therapy, clinical symptomatology and morphological findings suggest, though do not prove, that this patient's monophasic and probably immune-mediated disease is a rare fatal complication of fresh cell therapy.

Blood-Brain Barrier↗
PubMed1986

Muscarinic ganglionic stimulants: conformationally restrained analogues related to [4-[[N-(3-chlorophenyl)carbamoyl]oxy]-2-butynyl]trimethylammonium chloride.

The synthesis of a series of tertiary and quaternary cyclic analogues (isoarecolinol, dihydroisoarecolinol, arecolinol, and 3-pyrroline-3-carbinol derivatives) of [4-[[N-(3-chlorophenyl)carbamoyl]oxy]-2-butynyl]trimethylammonium chloride (McN-A-343) (1), a selective stimulant of muscarinic receptors in sympathetic ganglia (so-called M1 receptors), is reported. The compounds 3-10 were tested for muscarinic ganglion-stimulating activity by recording blood pressure responses in pithed rats. All tertiary compounds tested had no ganglion-stimulating activity. Among the series of quaternary derivatives, only the isoarecolinol analogues 4a and 4b showed considerable ganglion-stimulating effects, whereas the dihydroisoarecolinol (8), the arecolinol (6a, 6b), and the 3-pyrroline-3-carbinol derivatives (10) were much less potent. Our experiments therefore demonstrate that in this series a quaternary nitrogen atom, unsaturation at C2 of the ammonium side chain, and a certain spatial arrangement of the ammonium and the phenylcarbamate groups are essential for potent M1-receptor stimulating activity.

Animals↗