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Biomedical subjects

M Mayer

Publications and source records attributed to M Mayer.

At least 91 records · Page 5Linked to original sources
PubMed1997

Design of potent dynorphin A-(1-9) analogues devoid of supraspinal motor effects in mice.

Four analogues of dynorphin (Dyn) A-(1-9) incorporating D-Leu in position 8 alone or in combination with the nonhydrolysable psi [CS-NH] thiopeptide bond surrogate between positions 6 and 7 were tested in vitro for their ability to compete with the binding of selective kappa, mu, and delta opioid ligands, using membrane preparations of guinea pig cerebellum (kappa) and rat brain (mu and delta), for their ability to block the electrically induced contractions of the guinea pig ileum, and for their in vivo antinociceptive (writhing test) and motor (motor dysfunction assay) activities in mice. [D-Leu8]Dyn A-(1-9) displayed an affinity and a selectivity for the kappa opioid receptor that were comparable with those of Dyn A-(1-9). The potencies of [D-Leu8]Dyn A-(1-9) in the guinea pig ileum, writhing, and motor dysfunction assays were markedly enhanced (8-12 fold) compared with those of Dyn A-(1-9). [6 psi 7(CS-NH),D-Leu8]Dyn A-(1-9), [Lys6, 6 psi 7(CS-NH),D-Leu8] Dyn A-(1-9), and [Leu6, 6 psi 7(CS-NH), D-Leu8]Dyn A-(1-9) were somewhat less potent than [D-Leu8]Dyn A-(1-9) in all opioid assays. However, the thiopeptides were more potent analgesics than Dyn A-(1-9)(ED50 of 29.5, 23.9, and 15.5 nmol/mouse, respectively, compared with 90.7 nmol/mouse for Dyn A-(1-9)) and caused little or no motor impairment at analgesic doses.

2-Amino-5-phosphonovalerate↗
PubMed1997

Primary adhalinopathy (alpha-sarcoglycanopathy): clinical, pathologic, and genetic correlation in 20 patients with autosomal recessive muscular dystrophy.

Primary adhalin (or alpha-sarcoglycan) deficiency due to a defect of the adhalin gene localized on chromosome 17q21 causes an autosomal recessive myopathy. We evaluated 20 patients from 15 families (12 from Europe and three from North Africa) with a primary adhalin deficiency with two objectives: characterization of the clinical phenotype and analysis of the correlation with the level of adhalin expression and the type of gene mutation. Age at onset and severity of the myopathy were heterogeneous: six patients were wheel-chair bound before 15 years of age, whereas five other patients had mild disease with preserved ambulation in adulthood. The clinical pattern was similar in all the patients with symmetric characteristic involvement of trunk and limb muscles, calf hypertrophy, and absence of cardiac dysfunction. Immunofluorescence and immunoblot studies of muscle biopsy specimens showed a large variation in the expression of adhalin. The degree of adhalin deficiency was fairly correlated with the clinical severity. There were 15 different mutations (10 missense, five null). Double null mutations (three patients) were associated with severe myopathy, but in the other cases (null/missense and double missense) there was a large variation in the severity of the disease.

Adolescent↗
PubMed1997

[Intermediate term results after arthroscopic meniscus suture].

QUESTION: Do results after arthroscopic meniscal repair justify the bigger expenditure and the longer rehabilitation opposite to the arthroscopic menisectomy? METHOD: An arthroscopic meniscal repair in inside-out technique was carried out by the same surgeon in 35 consecutive patients with meniscal tears (tears at the meniscocapsular junction with best prognosis after repair are not subject of this study). Rehabilitation was standardized. After a mean follow-up time of 43 months, 27 (77%) of these patients, 12 without and 15 with an additional anterior cruciate ligament (ACL) reconstruction, were evaluated personally. RESULTS: There were 4 (14.8%) reruptures (3 true reruptures, 1 "rerupture" out of the repair side) and I lesion of the N. saphenus with limited dysaesthesia. Three of the 4 reruptures occurred in patients with isolated meniscal repair, only one in patients with additional ACL-reconstruction. The functional results (Lysholm-score, knee mobility) and the subjective result were good in patients without reruptures. Postoperatively, patients were unable for work and sports for a long time, but these times being shorter for isolated meniscal repairs (5.4 and 12 weeks respectively) than for patients with an additional ACL-reconstruction (12 and 29 weeks respectively). CONCLUSIONS: In terms of knee function and osteoarthrosis, arthroscopic meniscal repair has better results than partial meniscectomy and should be preferred, therefore, especially in young patients. A sufficient number of meniscus sutures should be performed and existing ligament instabilities should be repaired. A good rehabilitation program is essential. Efforts for a better acceptance of the method in patients and family doctors are necessary.

Adolescent↗
PubMed1997

Compliance to a gluten-free diet in adolescents, or "what do 300 coeliac adolescents eat every day?".

BACKGROUND/AIMS: Compliance to a gluten-free diet is currently an important issue in the care of both adolescent and adult coeliac patients. The aim of this study was evaluate the compliance to a gluten-free diet and the dietary habits in general of coeliac teenagers and young adults. PATIENTS AND METHODS: A total of 306 adolescents and young adults were followed in a coeliac clinic. They were grouped on the basis of: strict compliance to a gluten-free dietary regimen (n = 223, 73%); dietary transgressions 2-3 times/month (n = 46, 15%); and frequent transgressions or a full gluten-containing diet (n = 37, 12%). RESULTS: The physical growth status was optimal in the male patients, and less so in the females, but was not related to compliance. Symptoms were very rare in all groups. Compliance to the diet was related to sex (females better than males), age (younger better than older), good school grades, and good self-esteem. CONCLUSIONS: The teen-agers studied consumed an average of about 11.32 kg/month of gluten-free products provided by the Italian Health System. Gluten-free pasta and bread were the daily choices. The mean cost for each patient was estimated to be Italian Lire 242,640 (ECU 124) per month or ECU 1,490/year.

Adolescent↗
PubMed1996

Identification of a key recombinant narrows the CADASIL gene region to 8 cM and argues against allelism of CADASIL and familial hemiplegic migraine.

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CA-DASIL) is a nonarteriosclerotic, nonamyloid angiopathy characterized by recurrent subcortical ischemic strokes starting in midadulthood and frequently leading to pseudobulbar palsy and dementia. The disease locus has recently been mapped to chromosome 19q12. We have identified a chromosomal crossover in a clinically affected family member, which refines the localization of the CADASIL disease locus. Multipoint linkage analysis established the best estimate for the gene locus within an 8-cM interval bracketed by D19S226 and D19S222. This estimate strongly argues against allelism of CADASIL and familial hemiplegic migraine.

Alleles↗
PubMed1996

Persisting "writer's cramp" as a result of compensation of a temporary palsy due to a hereditary neuropathy with liability to pressure palsies.

A 49-year-old man reported several periods of acute paresis of different nerves after exposure to pressure. All palsies showed a good recovery over a period of days to months. The suspected diagnosis of a hereditary neuropathy with liability to pressure palsies was confirmed by the histology of a suralis nerve biopsy, which showed a distinct tomaculous swelling of the myelin. Nine years ago he noticed an acute, distally pronounced palsy of the right arm. A brachial plexus lesion was diagnosed. His profession required written work, thereby forcing him to compensate this weakness by increasing the coactivation of the elbow and upper arm. This coactivation persisted even after complete recovery from the plexus palsy. Thus, the patient showed the typical feature of classical writer's cramp, with broad coactivation of the arm muscles, which has continued to the present. At the same time, however, the patient was able to perform other motoric tasks well, such as painting. After several practice sessions with a special program that makes use of preserved motor abilities to reestablish writing, the patient was again able to write with a normal kinematic profile as documented by the recorded handwriting. This suggests that the "writer's cramp" of our patient is one form of task-related dystonia that may be related more to the perserveration of a misleading motor strategy than to a general inability of the motor system to control the movement properly.

Brachial Plexus↗
PubMed1996

The Internet: a modern Pandora's box?

Two different views of the Internet are presented. One is from the perspective of an author who has written a personal account of her own breast cancer experience, while the other is from the perspective of a cancer researcher who is interested in quality of life research. The article is written in a format that reflects the somewhat informal style of messages sent to Internet discussion groups. For better or worse, the Internet has arrived as a force in our lives, and medical information and support constitute two of its more important uses. Both authors agree that the novel medium of the Internet provides a unique opportunity to create a true partnership of health care providers and consumers.

Computer Communication Networks↗
PubMed1996

[Propofol and etomidate-Lipuro for induction of general anesthesia. Hemodynamics, vascular compatibility, subjective findings and postoperative nausea].

UNLABELLED: Etomidate has become an important induction agent in high-risk patients because of its cardiovascular stability. Its unwanted side-effects such as pain on injection and thrombophlebitis could be significantly reduced by a new (medium chain triglyceride and soya bean) emulsion formulation. Propofol is solved in a mixture of long chain triglyceride and soya bean emulsion. In this double-blind, randomized study we compared the haemodynamic effects, the patients' sensations, signs of thrombophlebitis and postoperative nausea and vomiting (PONV) following injection of both drugs. METHODS: Following premedication with 2 mg Lormetazepam p.o. in 50 patients per group, anaesthesia was induced with either 0.51 mg etomidate in lipid emulsion or 3.04 mg propofol per kg bw. No opioid or benzdiazepine was given i.v. before induction. After injection of the tested drug, the cannula was removed. Changes in blood pressure and heart rate were recorded as well as signs of discomfort during and after injection (pain, burning, tension, cold). Venous sequelae were assessed for 5 days after injection to register signs of thrombophlebitis. RESULTS: Demographic data showed no difference between the two groups. After propofol more often a fall in blood pressure was seen. Pain (25 vs 1 pt), burning 19 vs 1), tension 15 vs 3), cold (35 vs 17) after injection was registered significantly more often in the propofol group, whereas myocloni predominated in the etomidate group (13 vs 6) P < 0.05, chi-squared-test). No difference was seen in PONV in either groups. CONCLUSION: Etomidate formulated in a medium chain lipid emulsion causes significant less discomfort for the patients than propofol, which is solved in a long chain formulation. Myocloni, however, occur significantly more frequently after etomidate than after propofol.

Anesthetics, Intravenous↗
PubMed1996

Mitochondrial abnormalities and intrafamilial variability of sural nerve biopsy findings in adrenomyeloneuropathy.

Clinical and sural nerve biopsy findings in two brothers and their mother affected by adrenomyeloneuropathy/adrenoleukodystrophy (AMN/ALD) illustrate the variability of histopathological changes in this disorder. The number of diagnostic inclusions, i.e., trilaminar leaflets, varied considerably from case to case and showed no correlation to the extent of neurological symptoms. In addition, mitochondrial abnormalities (granular and filamentous inclusions and abnormal cristae), which have not previously been described in AMN/ALD, were detected. These alterations could be secondary to the peroxisomal defect and the increased amount of very long chain fatty acids or could be caused by a more generalized defect.

Adolescent↗
PubMed1996

In siblings of celiac children, rectal gluten challenge reveals gluten sensitization not restricted to celiac HLA.

BACKGROUND & AIMS: Inflammatory changes in the rectum of patients with celiac disease after local instillation of gluten have been reported. The aim of this study was to examine rectal mucosa after local gluten challenge in children with celiac disease and their siblings. METHODS: Rectal biopsy specimens were obtained before and 6 hours after rectal challenge with a peptictryptic digest of gliadin in 33 children with treated celiac disease, 12 controls, and 19 siblings of children with celiac disease. Epithelium and lamina propria volumes were determined, and CD3+ and gamma delta + lymphocytes were counted. RESULTS: After local instillation of gliadin, a significant increment in the absolute number of intraepithelial lymphocytes was noted in patients with celiac disease but not in controls. Immunohistochemical analysis showed a significant increase in CD3+ and gamma delta + cells, with the gamma delta/CD3 ratio remaining unchanged after challenge. A discriminant analysis allowed correct classification of 100% of patients with celiac disease and controls. The same analysis was used to classify 6 of 13 siblings as having celiac disease. The positivity was not associated with the presence of the heterodimer encoded by the DQA*0501 DQB1*0201 alleles in any of the siblings. CONCLUSIONS: All patients with celiac disease were identified by rectal gluten challenge. Approximately half of the siblings reacted to rectal instillation of gluten. The genetic background of such sensitization to gluten remains to be elucidated.

Adolescent↗
PubMed1996

Effect of oral antihistamine premedication on mivacurium-induced histamine release and side effects.

In this randomized, double-blind, placebo-controlled study, we have examined histamine release, haemodynamic and cutaneous effects of mivacurium administered in low (0.105 mg kg-1 = 1.5 x ED95) and high (0.21 mg kg-1 = 3 x ED95) doses and assessed if oral pretreatment with H1/H2 antagonists would blunt the effects of mivacurium-induced histamine release. Patients received either ranitidine 300 mg and dimethindene 0.1 mg kg-1 (H1 blocker) or placebo, orally 1 h before induction of anaesthesia. Twelve patients were allocated to each group. Although plasma concentrations of histamine increased significantly in three patients in the placebo group given low-dose mivacurium, the mean value for the group was unchanged. Plasma concentrations of histamine increased significantly in five patients in the placebo group after high-dose mivacurium and the mean value was increased. There was no consistent correlation between haemodynamic changes, cutaneous manifestations and histamine concentrations. Significant cardiovascular reactions occurred in six patients in the placebo groups and in only one patient treated with antihistamines.

Adolescent↗
PubMed1996

Human follicular nitric oxide pathway: relationship to follicular size, oestradiol concentrations and ovarian blood flow.

Nitric oxide (NO) has been suggested to be involved in ovarian physiology. Our aim was to study follicular nitrite and nitrate (NO3/NO2) levels in women undergoing in-vitro fertilization (IVF), and to examine their relationship to follicular size, oestradiol concentrations, and ovarian artery and intra-ovarian blood flow as measured by Doppler ultrasound. A total of 15 patients from the IVF programme of Hadassah University Hospital, Mt Scopus, Israel, participated in the study. Detailed transvaginal ultrasonographic examination was performed before ovum collection, and ovarian artery and intra-ovarian blood flow were measured. While aspirating the follicles, the content of two to four of the follicles in each ovary was collected individually, the volume of follicular fluid measured, and NO3/NO2 concentrations were determined. A statistically significant positive correlation was found between follicular fluid NO3/NO2 concentrations and follicular volume (r = 0.76), as well as between NO3/NO2 concentrations and oestradiol concentrations (r = 0.63). A statistically significant negative correlation was found between follicular fluid NO3/NO2 concentrations and ovarian flow parameters as well as between NO3/NO2 concentrations in follicles containing 4-5 ml and ovarian artery pulsatility index.

Adult↗
PubMed1996

Reconstruction of the spinal accessory nerve with an anastomosis to the dorsal C3 branch: technical note.

Most lesions of the spinal accessory nerve are of traumatic origin. If the proximal part is sectioned next to its exit from the cranial base, the reconstruction might be difficult. In such a case, one option is intracranial identification of the spinal accessory nerve and transdural interposition of a graft to its distal stump. Cerebrospinal fluid leaks or infections, caudal nerve palsies, or even spinal neurological deficits are possible complications. From more than 70 patients who underwent selective peripheral denervations for the treatment of spasmodic torticollis in our department, we have learned that the dorsal C1-C6 branches can be sectioned without any functional impairment. The dorsal C2 and C3 branches have diameters comparable to that of the spinal accessory nerve. They contain between 600 and 700 myelinated fibers per square millimeter. Therefore, they seem to be ideal proximal donors for the reconstruction of a severed motor nerve. They may be used in patients with peripheral nerve injuries in the craniocervical region, if other possibilities are not suitable.

Accessory Nerve↗
PubMed1996

Maxillary alveolar cleft repair in dogs using recombinant human bone morphogenetic protein-2 and a polymer carrier.

Recombinant human bone morphogenetic protein-2 was evaluated in maxillary alveolar clefts in 24 adult, skeletally mature Foxhound dogs. Bilateral clefts were prepared, 1 cm in bony width, lined with healthy epithelium with functional teeth on each side, and were expected not to heal spontaneously with new bone. Preparation of bilateral clefts in 24 dogs permitted 48 recipient sites divided evenly among four treatment and two time periods (2 and 4 months), yielding six replicates per treatment per time. The overall goal for the study was to regenerate bone in the cleft using one of three treatments: (2) 200 microgram recombinant human bone morphogenetic protein-2 combined with the copolymer poly(lactide-co-glycolide) and autogenous blood, (2) poly(lactide-co-glycolide) and autogenous blood, or (3) an autograft from the posterior iliac crest. A fourth group consisted of untreated alveolar cleft defects. At designated times, dogs were euthanized, and the recipient beds with contiguous bone were recovered, processed, and assessed radiographically and histologically. Autograft-treated defects had more bone than other treatments at 2 months; however, by 4 months, there were no differences among treatments, except for the poly(lactide-co-glycolide) group, which had the least amount of bone. Response to the recombinant human bone morphogenetic protein-2 may have been suboptimal either because the dose was too low or because the poly(lactide-co-glycolide)-autogenous blood delivery system did not temporally maintain and spatially position recombinant human bone morphogenetic protein-2 at the recipient bed. In addition, the development of a nonhealing, critical-sized defect in the maxilla of the dog appears to require a more aggressive resection of bone to preclude spontaneous osseous regeneration.

Alveolar Process↗
PubMed1996

Latent and potential coeliac disease.

Under the umbrella of coeliac disease (CD), or gluten-sensitive enteropathy, the concepts of silent, latent and potential CD have recently been introduced. While silent CD is marked by severe damage to the jejunal mucosa in the absence of clinical symptoms, both latent and potential CD are characterized by jejunal mucosa that would be reported as normal by most clinical pathologists in an individual on a gluten-containing diet. As opposed to potential coeliac patients, latent subjects sometimes in their life have had a flat jejunal biopsy which recovered on a gluten-free diet. Latent coeliac patients are often symptomatic; neither high titres of gliadin antibodies nor mucosal changes (including raised intraepithelial lymphocyte counts) are obligate features of latent CD, although the presence of elevated endomysial antibodies is probably the best predictor of progression towards villous atrophy. The term potential CD has been proposed for those subjects who do not have, and have never had, a jejunal biopsy consistent with overt CD, and yet have immunological abnormalities similar to those found in coeliac patients. Good markers of potential CD include the presence of serum endomysial antibodies, a high count of intraepithelial lymphocytes and subtle pathological alteration such as increased density of intraepithelial lymphocytes expressing gamma delta T cell receptor, signs of activated mucosal cell-mediated immunity, coeliac-like intestinal antibody pattern, and positive rectal gluten challenge.

Antibodies↗