Investigations of low-temperature storage of articular cartilage for transplantation

Isolated bovine articular cartilage chondrocytes and intact slices of cartilage were investigated to determine the effects of low-temperature cryopreservation on articular cartilage. Studies have focused on prefreezing conditions of cartilage, including the incubation medium and temperature of incubation, type and toxicity of the cryopreservative used, and the penetration of cryopreservative agents into cartilage cells. Cartilage freezing conditions were examined with respect to rate of freezing, controlled differential freezing rates, the ultimate storage temperature, and the time of storage. Cartilage thawing conditions were observed to ascertain the role of membrane osmotic stress during thawing and the effect of variable thawing rates on the viability of chondrocytes. Careful control of these variables can yield cartilage with cellular viability of over 50%. Optimum cryopreservation of viable cartilage should include prefreezing treatment with 7.5%-10% DMSO in nutrient medium, controlled slow freezing to -70 degrees, and rapid thawing in DMSO containing medium. A significant number of chondrocytes in deep-frozen cryopreserved articular cartilage can survive. The work recommends continued clinical use of deep-frozen cartilage.     

Core body temperature in the elderly and factors which influence its measurement

Several studies have reported that core body temperature decreases with age and has greater variability in older populations. Furthermore, oral measurement, the most frequently used clinical method for determining fever, may not accurately reflect core body temperature. This study was designed to compare accurate measurements of oral and core body temperatures in a group of 93 healthy subjects, aged 62-96, under controlled conditions. Increasing age, presence of dentures, and type of thermometer were examined to determine if they affect body temperature measurements. Core temperatures did not show a negative relationship with advancing age (r = -0.02) nor did variation in temperatures increase with age. Neither the type of thermometer nor the presence of dentures significantly affected the measurement of temperature.     

Social competence and head injury: a practical approach

Social competence assessment and training has long focused on specific skills within the clinical setting. In addition, emphasis has been placed on identifying deficits relative to an arbitrary, often idiosyncratic metric. In this article, we discuss the importance of the principles that underlie communication and which are reflected in the range of behaviours described as social competence . We review methods we have found productive in the training of these principles with persons who have suffered traumatic brain injuries.     

Acetabular preparation in cementless revision total hip arthroplasty

The rationale for and experience with the use of a hemispherical, cementless, microporous socket (Harris-Galante prosthesis) are presented as an approach to acetabular revision arthroplasty. Advantages are noted in preservation of existing bone, ease of rigid fixation, and bone grafting with either lyophylized particle allograft or autograft. The early results of a series of 75 sockets show no loss of fixation, mild to major resorption of non-contained bone graft, and favorable roentgenographic appearance of contained bone graft. In bone-grafted regions, a high percentage of lucencies at the graft-porous interface implies a lack of bone ingrowth. The authors were unable to characterize any roentgenographic behavioral differences between allograft or autograft. The approach is successful in severely deficient acetabulae, especially of the Type III combined cavitary and segmental medial wall deficiency.     

Distribution of spermatogenesis in the testicles of azoospermic men: the presence or absence of spermatids in the testes of men with germinal failure [published erratum appears in Hum Reprod 1998 Mar;13(3):780]

The aim of the study was to determine whether a prior diagnostic testicle biopsy can predict success or failure of testicular sperm extraction (TESE) with intracytoplasmic sperm injection (ICSI) in patients with non-obstructive azoospermia caused by testicular failure, and what is the minimum threshold of sperm production in the testis which must be surpassed for spermatozoa to reach the ejaculate. Forty- five patients with non-obstructive azoospermia caused by testicular failure underwent diagnostic testicle biopsy prior to a planned future TESE-ICSI procedure. The diagnostic testicle biopsy was analysed quantitatively, and correlated with the quantitative findings of spermatogenesis in patients with normal spermatogenesis, as well as with the results of subsequent attempts at TESE-ICSI. Men with non- obstructive azoospermia caused by germinal failure had a mean of 0-6 mature spermatids/seminiferous tubule seen on a diagnostic testicle biopsy, compared to 17-35 mature spermatids/tubule in men with normal spermatogenesis and obstructive azoospermia. These findings were the same for all types of testicular failure whether Sertoli cell only, maturation arrest, cryptorchidism, or post-chemotherapy azoospermia. Twenty-two of 26 men with mature spermatids found in the prior testis biopsy had successful retrieval of spermatozoa for ICSI, 12 of their partners became pregnant, and are either ongoing or delivered. The study suggests that 4-6 mature spermatids/tubule must be present in the testis biopsy for any spermatozoa to reach the ejaculate. More than half of azoospermic patients with germinal failure have minute foci of spermatogenesis which are insufficient to produce spermatozoa in the ejaculate. Prior diagnostic testicle biopsy analysed quantitatively (for the presence of mature spermatids) can predict subsequent success or failure with TESE-ICSI. Incomplete testicular failure may involve a sparse multi-focal distribution of spermatogenesis throughout the entire testicle, rather than a regional distribution. Therefore, it is possible that massive testicular sampling from many different regions of the testes may not be necessary for successful TESE-ICSI.      

Adhesion inhibitory activity of β-lactoglobulin isolated from infant formulae

β-Lactoglobulin was isolated from infant formulae that were ultra high temperature (UHT) -treated, sterilized or spray-dried. The effect of the isolated β-lactoglobulin on SfaII-fimbriae-mediated adhesion of Escherichia coli to human ileostomy glycoproteins was studied in vitro. β-Lactoglobulin isolated from sterilized formulae was found to perform significantly less well than preparations from spray-dried formulae (p = 0:05). Great heterogeneity was observed in the adhesion inhibitory capacity of β-lactoglobulin isolated from UHT-treated formulae. Therefore, no significant difference was observed between UHT-treated and sterilized formulae or spray-dried formulae (p < 0:10). It can be hypothesized that β-lactoglobulin from spray-dried and some UHT-treated infant formulae may affect the colonization of mucous membranes by E. coli strains causing neonatal septicaemia and meningitis.     

Mutations in the retinal guanylate cyclase (RETGC-1) gene in dominant cone-rod dystrophy

The dominant cone-rod dystrophy gene CORD6 has previously been mapped to within an 8 cM interval on chromosome 17p12-p13. The retinal- specific guanylate cyclase gene (RETGC-1), which maps to within this genetic interval and previously was implicated in Leber's congenital amaurosis, was screened for mutations within this family and in a panel of small families and individuals with various cone and cone- rod dystrophy phenotypes. A missense mutation (E837D) was identified in affected members of the CORD6 family, as well as a second missense mutation (R838C) in three other families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene to be implicated in cone-rod dystrophy and this is the first report of dominant mutations in this gene.