Expression of rabbit Ig allotypes in litters of mothers immunized against a paternal allotype.

Sera of successive littermates of mothers producing anti-allotype antibodies (Ab) were analysed for altered a locus or b locus allotype expression. We measured the allotype concentration in sera of 66 individuals (17 litters) of seven mothers producing anti-a1 Ab, and 63 individuals (15 litters) of seven mothers producing anti-b4 Ab, in an enzyme-linked immunosorbent assay (ELISA). We confirmed that the ability to induce allotype suppression in utero increases with the number of antigen boosts applied to the mother, even though the Ab titre in the maternal serum may be decreased. All individuals of a litter expressed the allotype in about equal concentration. This contrasts the results we obtained when newborn rabbits were injected with anti-allotype antiserum. Injection of the same amount of anti-allotype antiserum into nine offspring of two mothers caused allotype suppression in only five individuals, showing no effect in the others. No suppression was observed when IgG-depleted antiserum was injected into newborn rabbits. As expected, maternal antibodies to a paternal allotype do not affect the Mendelian distribution of the progeny phenotypes.     

Gender differences in suprathreshold taste scaling ability in an older population

Taste sensitivity was evaluated by suprathreshold scaling of six concentrations each of sodium chloride, sucrose, citric acid, and quinine hydrochloride. Magnitude estimation was used as the method of scaling. The study group was composed of 22 males and 19 females were either patients (institutionalized) or staff members of the Jewish Institute for Geriatric Care. Data from each patient were used to compute individual slopes and Y-intercepts of the log to log transformations for each solution sequence. The mean age of the persons who were institutionalized was significantly higher than that of the staff members. In addition, the mean age of the females was 10 years older than that of the males. The older adult males seemed to have impaired taste function that resulted in significant decreases in total perceived intensity of several taste solutions. No significant differences were shown in taste ability between the relatively healthy younger staff member subjects and the older, more infirm, institutionalized subjects.     

Lumbar spondylolysis and spondylolisthesis in college football players. A prospective study

A prospective study was done on Indiana University freshman football players to determine if the incidence of lumbar spondylolysis and spondylolisthesis followed the pattern of previous studies. Using x-ray film evaluation, 145 freshman players were followed through their careers from 1978 to 1983. As in previous studies, a higher percentage (15.2%) of the defect was found than exists in the general population. However, only 2.4% of these players developed the problem in college, a much lower figure than previously found. Affected team members played a variety of positions. In addition to spondylolysis, some other problems, such as spina bifida occulta, were found. Theories on the cause of spondylolysis and spondylolisthesis are reviewed, and preventive suggestions such as more careful training and weight lifting are presented.     

Regional cerebral glucose transport in insulin-dependent diabetic patients studied using [11C]3-O-methyl-D-glucose and positron emission tomography

Regional cerebral [11C]3-O-methyl-D-glucose ([11C]MeG) uptake kinetics have been measured in five insulin-dependent diabetic patients and four normal controls using positron emission tomography (PET). Concomitant measurement of regional cerebral blood volume and CBF enabled corrections for the presence of intravascular [11C]MeG signal in cerebral regions of interest to be carried out, and regional cerebral [11C]MeG unidirectional extraction fractions to be computed. Four of the five diabetic subjects were studied with their fasting plasma glucose level clamped at a normoglycaemic level (4 mM), and four were studied at hyperglycaemic plasma glucose levels (mean 13 mM). The four diabetic subjects whose fasting plasma glucose levels were clamped at a normoglycaemic level of 4 mM had mean fasting whole-brain, cortical, and white matter [11C]MeG extraction fractions of 15, 15, and 16%, respectively, values similar to those found for the four normal controls (whole brain, 14%; cortex, 13%; white matter, 17%). Mean regional cerebral [11C]MeG extraction fractions were significantly reduced in diabetic subjects during hyperglycaemia whether their plasma insulin levels were undetectable or whether they were raised by continuous intravenous insulin infusion. Such a reduction in [11C]MeG extraction under hyperglycaemic conditions can be explained entirely in terms of increased competition between [11C]MeG and D-glucose for the passive facilitated transport carrier system for hexoses across the blood-brain barrier (BBB). It is concluded that the number and affinity of D-glucose carriers present in the BBB are within normal limits in treated insulin-dependent diabetic subjects. In addition, insulin appears to have no effect on the transport of D-glucose across the BBB.     

Flow requirements for the Bain breathing circuit during anaesthesia for caesarean section

We studied the relationship between arterial carbon dioxide tension (PaCO2) and fresh gas flow (FGF) during use of the Bain breathing circuit for Caesarean section anaesthesia. Thirty-one patients undergoing Caesarean section were anaesthetised using the Bain circuit with intermittent positive pressure ventilation. The PaCO2 were measured at FGF of 70 ml X kg-1 X min-1, 80 ml X kg-1 X min-1, and 100 ml X kg-1 X min-1. The FGF requirement to maintain a given PaCO2 during Caesarean section anaesthesia is the same as the requirements for nonpregnant subjects, despite the increase in carbon dioxide production associated with pregnancy. This is probably because the total FGF determined by body weight and given during Caesarean section anaesthesia is 15-20 per cent higher than nonpregnant levels, due to the weight gain associated with pregnancy. A FGF of 100 ml X kg-1 of pregnant weight/min maintains PaCO2 of 4.44 kPa predelivery, which is in the desirable range of PaCO2 during Caesarean section.     

Localized osteolysis in stable, non-septic total hip replacement

We are reporting four cases of extensive, localized bone resorption adjacent to a rigidly anchored, cemented total hip replacement. None of these hips showed evidence of infection on clinical, bacteriological, or pathological evaluation. The tissue from the regions of osteolysis showed sheets of macrophages and foreign-body giant cells invading the femoral cortices. Abundant methylmethacrylate particulate debris was present in the tissues, but polyethylene wear debris was absent. The histological appearance of this tissue resembled that reported about loosened total hip implants with the exception of the synovial-like layer at the cement surface. The cases reported here show that aggressive bone lysis may occur around stable cemented total hip arthroplasties without the presence of sepsis or malignant disease.