Silk as a biomaterial

Food specimens have been collected, by means of the double-portion technique, from Greenland Eskimo hunters and their wives, in all seven persons, on seven consecutive days. Their food was found to contain more protein and less carbohydrates than average Danish food and an almost equal amount of fat. Compared with Danish food, the fatty acid pattern of the consumed lipids--essentially of mammalian marine origin--showed a higher content of long chain polyunsaturated fatty acids (especially C20:5) and lower contents of linoleic and linolenic acids. However, the sum of the polyunsaturated fatty acids was smaller than in Danish food. Using Keys' formula, describing the serum cholesterol level as a function of the nutritional fatty acids, the essentially lower serum choelsterol level found in Greenland Eskimos was not explained by our findings. It is suggested instead to be a special metabolic effect of the long chain polyunsaturated fatty acids from marine mammals. There might be a similar effect on the plasma triglyceride and very low density lipoprotein concentrations, explaining the much lower plasma concentrations of these components in Eskimos than in Western populations. Our findings might have an essential bearing on the difference in morbidity from coronary atherosclerotic disease between these populations.

The composition of food consumed by Greenland Eskimos.

This paper reviews recent work involving polymeric biomaterials used for skin, cartilage, bone, vascular, nerve and liver regeneration. Skin trauma involves damage to the epidermal, dermal and/or subdermal tissues. Epithelial, dermal and full-thickness replacements are considered. Cartilage research is mainly focused on replacing hyaline cartilage. Researchers investigate both nondegradable polymers, which must provide mechanical stability, and degradable polymers, which must support cartilage regeneration. Natural healing in large bone defects often fails. Materials for bone reconstruction must be biocompatible, offer mechanical properties similar to those of bone and support tissue regeneration. The area of vascular grafts draws attention as improvements to the patency of existing materials are needed. Studies to improve current vascular graft polymers as well as develop new polymers are reviewed below. The design and testing of materials for nerve regeneration, to repair damage caused by illness or accident, is an active area of research. Directional nerve guidance via tubulation is discussed, as are matrix materials to enhance axonal extension. Finally, liver transplantation remains one of the only options for chronic liver disease and the demand for liver transplants far exceeds the number of available organs. The complexity of parameters involved in liver regeneration is presented here.

Polymeric biomaterials for tissue and organ regeneration

Evolution of bone transplantation: molecular, cellular and tissue strategies to engineer human bone *

Review on titanium and titanium based alloys as biomaterials for orthopaedic applications.

The prognostic value of histopathologic grading of oral squamous cell carcinomas (SCC) has varied from not any to highly significant. We have retrospectively studied all (130) SCCs registered in Norway 1963-72 in the buccal and maxillary alveolar mucosa. From 68 of these cases biopsy specimens of acceptable quality were obtained. Broders' method of grading was compared with a modification of a recent malignancy grading system recommended by Anneroth et al. which was performed only within the histologically most invasive areas of the tumors. Cox's multivariate survival analyses showed that this grading in the invasive sites had highly significant prognostic value. Broders grade had no prognostic value. The stage of tumor had also prognostic value. These highly significant results indicate that the histologically invasive areas may be primarily responsible for the clinical behavior of the tumor, and this may be of importance for the choice of therapy for oral SCC.

New malignancy grading is a better prognostic indicator than Broders' grading in oral squamous cell carcinomas.

(1970). Determination of Age in Humans from Root Dentin Transparency. Acta Odontologica Scandinavica: Vol. 28, No. 1, pp. 3-35.

Determination of age in humans from root dentin transparency.

The chromosomal findings in 10 adenoid cystic carcinomas (ACC) of the salivary glands are described. Clonal numerical deviations as the sole anomaly were detected in four cases and structurally rearranged stemlines and sidelines in four cases. An apparently identical t(6;9)(q23;p21) was found in two tumors; in one case the translocation was part of the abnormal stemline and in the other case it was the sole anomaly in a single variant cell. A similar or identical t(6;9)(q21-24;p13-23) has recently been reported in three of 15 previously published cases of ACC. The three remaining tumors with abnormal stemlines all had rearrangements of chromosome 9, including t(1;9)(q21;p21-22), der(9)i(9)(q10)inv(9)(q12q 13), and der(X)t(X;9)(p21;p22-23), respectively. The latter case also had a t(17;18)(p12;q11.2) that was common to both abnormal clones present in this tumor. In addition to other abnormalities, the clone with der(X)t(X;9) also showed a del(6)(q13q21). In two cases fluorescence in situ hybridization (FISH) was used for further characterization of the marker chromosomes. A survey of the present findings together with previous results from 15 ACC clearly demonstrates that rearrangements of 6q21-24 (deletions or translocations in 11 cases), 9p13-23 (translocations in seven cases), and 17p12-13 (translocations in three cases) are recurrent, and often primary, in ACC, and that the t(6;9)(q21-24;p13-23), found in five tumors, is a non-random, primary aberration. Genes Chromosom Cancer 10:115–121 (1994). © 1994 Wiley-Liss, Inc.

Non‐random chromosome rearrangements in adenoid cystic carcinoma of the salivary glands

The purpose of the study was to examine if Bio-Oss initiated osteoinduction or osteoconduction when implanted into rats. Sintered and unsintered granules of the anorganic bovine bone Bio-Oss was implanted subperiosteally for alveolar ridge augmentation purposes and heterotopically in the abdominal muscles of rats. Light microscopic evaluation revealed no osteoinduction or osteoconduction in connection with sintered or unsintered Bio-Oss. A foreign body reaction was observed around both forms.

Alveolar ridge augmentation in rats by Bio-Oss.

Three cases of a newly described rare odontogenic tumor are reported. One patient died with pulmonary metastases, one had an associated odontogenic cyst and one exhibited regional lymph node metastasis. The cases lend support to the odontogenic origin and metastatic capability of the clear cell odontogenic tumor. The authors recommend aggressive therapy and believe that the tumor should be considered a clear cell odontogenic carcinoma.

Gisle Bang

Papers

New malignancy grading is a better prognostic indicator than Broders' grading in oral squamous cell carcinomas.

Determination of age in humans from root dentin transparency.

Non‐random chromosome rearrangements in adenoid cystic carcinoma of the salivary glands

Alveolar ridge augmentation in rats by Bio-Oss.

Clear cell odontogenic carcinoma: report of three cases with pulmonary and lymph node metastases