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Biomedical subjects

R Neugebauer

Publications and source records attributed to R Neugebauer.

86 records · Page 5Linked to original sources
PubMed1980

[The use of carbon fiber strands for replacement of collateral ligaments at the knee joint (author's transl)].

Two different anchorage systems of carbon fiber strands were tested on 16 human cadaver knees. To pull the C-strands out of the scale and channel anchorage almost the same force was necessary as to break the natural collateral ligaments. The ingrowth of connective tissues and newly formed bone around the C-fibers was studied in 11 sheep. A biomechanical strength test revealed, 3 months after implantation, a 60% strength compared to the natural ligaments. Histologically a C-fiber connective tissue composite with collagen fibers was found. Newly formed bone closely surrounded the carbon. These results indicate that carbon fiber strands are suitable for ligament replacement, which allows early joint motion. Good long-term results could be assumed as a result of the high biocompatibility.

Biomechanical Phenomena↗
PubMed1980

[In vivo synthesis of cartilage after transplantation of chondrocytes in animal experiments (author's transl)].

Long-term results after cartilage transplantation are not satisfactory owing to poor viability of the chondrocytes. In vitro experiments with isolated fetal and neonatal rabbit chondrocytes revealed a much better proliferative ability compared with adult cartilage derived cells. Cryopreservation of cell suspensions did not decrease the proliferative ability. In in vivo experiments, cultured neonatal, fetal, and cryopreserved rabbit chondrocytes were tested in transplants and compared with cell-free controls or radiated chondrocytes. These chondrocytic transplants showed good viability and seemed to synthesize cartilage matrix, which could be stained with safranin, whereas only fibrous tissue was found in controls.

Animals↗
PubMed1979

Medieval and early modern theories of mental illness.

Historians of medieval and early modern psychiatry have utilized limited source materials in their research. They have focused on printed works, particularly formal treatises by celebrated authors, and neglected manuscript collections. The resulting histories depict early European psychiatric thought as dominated by demonology. Examination of the archives of an early English legal incompetency jurisdiction flatly contradicts this picture. Starting in the 13th century, the English government conducted mental status examinations of psychiatrically disabled individuals, using commonsense, naturalistic criteria of impairment; private, supervised guardians were appointed for such persons. Furthermore, etiological theories entertained by royal officials and laymen relied on physiological and psychological notions of psychiatric illness. These findings raise serious questions about conventional accounts of this period and underline the need for more research using original manuscripts.

England↗
PubMed1979

[Plastic replacement of the abdominal wall by uncoated carbon cloth. An animal experiment on the rabbit (author's transl)].

Carbon cloth is a new biomaterial which is suitable for the replacement of ligaments and connective tissues, because of its biological and physical properties. In 30 rabbits a defect was cut into the abdominal wall. In 20 the defect was covered by an implanted carbon cloth. The other 10 animals were used as controls. After implantation wound healing was excellent. No herniation could be observed in the group with the implants. After 3 months histological examinations revealed the ingrowth of collagen fibres into the carbon cloth. It had become a strong and resilient abdominal wall replacement. A physical-strength test showed stability of the newly formed abdominal wall with good anchorage to normal tissue.

Abdominal Muscles↗
PubMed1979

[Studies on the intra-osseous fastening of alloplastic ligament substitutes in sheep using carbon fibers].

The alloplastic replacement of the medial collateral ligament of the knee of sheep by carbon fibers gave a strength comparable with the natural ligament. Coating of the fibers, e.g., with epoxy resin, leads to a reduced integration of the implant into the tissues. Physical and histologic results together with the intraosseus anchorage show that pure carbon fibers are a suitable material for alloplastic ligament replacement.

Animals↗
PubMed1978

[Multiple cavernous haemangiomas of the colon (author's transl)].

Extensive involvement of the colon with cavernous haemangioma is described in a 26-year old man. Clinically the disease manifests itself by recurrent rectal bleeding and abdominal distension, leading to his admission. Double contrast examination of the colon showed involvement of the ascending, transverse and descending colon, the sigmoid and the rectum. Arteriography demonstrated vascular tumours in the territory of the jejunal artery, the left colic artery and the superior rectal artery. This is a rare condition which has been described only 53 times in the literature (1, 3, 5, 7). The diagnostic value of double contrast examination of the colon and of selective angiography for differential diagnosis is stressed.

Adult↗
PubMedDate not supplied

Stressful life events and seizure frequency in patients with epilepsy.

We tested whether unpleasant life events increased seizure occurrence in persons with epilepsy. Forty-six subjects maintained daily diaries for 10-36 weeks in which they recorded seizures and life events. Mean age of subjects was 39 years; 78% were female; 83% had complex partial seizures (CPS). On the average, subjects reported 3.3 seizures a week. Analyses first were conducted within each subject and then in the sample overall. For each person, we tested whether seizure frequency increased within 24 h of the occurrence of unpleasant events, using Poisson regression analyses that adjusted for daily antiepileptic medication, sleep duration and quality, alcohol intake, menstrual status, and pleasant events. Rarity of events precluded analyses in 9 subjects. Events increased seizure frequency in 5 subjects (14%) (p < 0.05). Events decreased seizure frequency in 2 subjects (p < 0.05). When individual risk ratios were aggregated across subjects, unpleasant events were significantly associated with seizure increase only in men (RR = 1.67, 95% Confidence interval 1.09, 2.54). However, this finding must be interpreted with caution because of the limited number of men in the sample. In other aggregate analyses, events and seizures were not associated in subjects grouped by seizure type, age of seizure onset, current age, ethnicity, educational level, or marital status. Identification of factors that distinguish patients with and without event-triggered seizures requires further study.

Adolescent↗