Identification of localized autoantibody epitopes in thyroid peroxidase

Recent reports have disagreed on the nature of the autoantibody epitopes in thyroid peroxidase (TPO). We used immunoprecipitation of recombinant human TPO constructs to determine if localized autoantibody binding sites exist in this autoantigen. In vitro transcription and translation of TPO cDNA fragments yielded 35S-labeled products consisting of either full-length protein (933 amino acids) or N-terminal peptides of 631, 455, and 120 amino acids. Immunoprecipitates analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography revealed that the Hashimoto's sera consistently precipitated the full-length and the 631 amino acid products, but not the shorter N-terminal peptides. An additional construct resulting in a full-length TPO peptide with an internal deletion of amino acids 4-455 was also made, and this product was also precipitated by the Hashimoto's sera. A fusion protein consisting of maltose binding protein followed by amino acids 456-933 of human TPO was produced in Escherichia coli and subjected to Western blot analysis using the Hashimoto's sera. The Hashimoto's sera reacted with the MalTose binding protein TPO (MBP/TPO) fusion protein, but not a control fusion protein (MBP/LacZ alpha). Together, these results indicate the presence of localized autoantibody epitopes in the portion of the human TPO molecule from amino acids 456 to 933, with at least one binding site located between amino acids 456 and 631.

Immunoreactivity to Yersinia enterocolitica antigens in patients with autoimmune thyroid disease

Recent reports have suggested that Yersinia enterocolitica proteins encoded by a 72-kilobase virulence plasmid (known as release proteins and now identified as YOP2-5) are antigens recognized specifically by patients with Graves' disease and of potential etiological importance in this disorder. To examine this hypothesis, we evaluated immune responses to YOP in patients with autoimmune thyroid disease and in normal controls. Humoral responses to Yersinia were assessed using Western blots of crude Y. enterocolitica membrane proteins, Yersinia release proteins (YOP2-5), and human thyrocyte membranes. Twenty-four of 25 Graves' and 10 of 18 Hashimoto's patients showed reactivity with the release proteins, primarily the 67-, 46-, 36-, and 25-kilodalton bands. However, 17 of 24 normal subjects also demonstrated serological reactivity to the release proteins, and the pattern of reactivity of these sera was similar to that in the thyroid patients. No correlation was noted between serological reactivity to the release proteins and thyroid hormone levels. Patients and controls with serological reactivity to YOP also showed reactivity with Yersinia membranes. In addition to the serological studies, cellular immune responses were determined by peripheral blood mononuclear cell proliferation assays. Cellular reactivity to the release proteins was present in four of five Graves' and both Hashimoto's patients tested, but also in two of six nonthyroid illness patients with serological immunity to the release proteins. Intrathyroidal lymphocytes obtained from two Graves' patients demonstrated marked proliferation in response to the release proteins. These results indicate that there is no unique pattern of serological reactivity against Yersinia membranes or the release proteins in patients with autoimmune thyroid diseases and suggest that any causal relationship between Yersinia infection and Graves' disease may be related to T-cell immunity.

Causes of mortality and parasites and incidental lesions in dolphins and whales from British waters

Detailed post mortem examinations were carried out on 18 dolphins and whales found dead on the coast of the United Kingdom. The commonest causes of death were pneumonia and entanglement in fishing gear. Of the non-fatal conditions, parasitoses of various organs were common and there was a wide variety of other conditions. In total 124 diseases and other lesions were found, giving an average of 6.9 conditions per animal.

Causes of mortality and parasites and incidental lesions in harbour porpoises (Phocoena phocoena) from British waters

Detailed post mortem examinations were carried out on 41 harbour porpoises (Phocoena phocoena) found dead on the coast of the United Kingdom. The commonest causes of death were entanglement in fishing gear, and parasitic and bacterial pneumonia. Among the non-fatal conditions parasitoses of various organs were common and there was a very wide variety of other conditions. In total 295 diseases and other lesions were found, an average of 7.2 per animal.

T-lymphocyte activation in adult-onset idiopathic hypoparathyroidism

PURPOSE

Patients with adult-onset idiopathic hypoparathyroidism (AOIH) often have antibodies against the parathyroid glands and other tissues, suggestive of immune activation. The purpose of this study was to determine whether T-cell activation is also a component of the endocrine disease.

PATIENTS AND METHODS

We identified eight patients with idiopathic hypoparathyroidism diagnosed after the age of 30 years at two tertiary care centers and evaluated peripheral blood lymphocyte subset phenotype frequencies using monoclonal antibodies and flow cytometry. Control subjects were 13 patients with Graves' disease (five thyrotoxic and eight euthyroid) and 110 healthy volunteers. In two of the patients with AOIH, we also determined the mitogenic response to parathyroid cell membranes in peripheral lymphocytes.

RESULTS

Patients with AOIH had higher than normal frequencies of the following phenotypes (p less than 0.05 versus controls, one-way analysis of variance): CD4, helper T cells; CD29/CD4, inducer of helper T cells; CD16 and CD56, natural killer cells; and CD3/DR, activated T cells coexpressing DR. Patients with Graves' disease had significantly higher than control frequencies of CD25 (T cells bearing the interleukin-2 receptor), CD3/DR, and CD26 (also a marker of T-cell activation); whereas the frequency of CD29/CD4 was significantly less than the control frequency. Neither of the two AOIH patients tested showed lymphocyte proliferation in response to parathyroid or thyroid cell membrane fractions.

CONCLUSIONS

Generalized T-cell activation represents a novel feature associated with AOIH. Although we could not demonstrate parathyroid-specific lymphocyte clonal expansion, these data are suggestive of a generalized immune disturbance possibly related to autoimmunity, in which one of the manifestations is hypoparathyroidism.

Ex vivo gene therapy of familial hypercholesterolemia

Familial hypercholesterolemia (FH) is an autosomal dominant disorder caused by a deficiency in the receptor that clears low density lipoprotein (LDL) from the serum (reviewed in Ref. 1 and 2). Patients with one abnormal LDL receptor allele have moderate elevations in plasma LDL and suffer premature coronary artery disease (CAD). Approximately 5% of all patients under 45 who have had a myocardial infarction carry this trait. Patients with two abnormal LDL receptor genes (homozygous deficient patients) have severe hypercholesterolemia and life-threatening coronary artery disease in childhood. Strategies for treating patients with FH are directed at lowering the plasma level of LDL. In heterozygotes, this is accomplished through the administration of drugs that stimulate the expression of LDL receptor from the normal allele (2). This therapeutic approach is not effective in the treatment of homozygous deficient patients, especially those that retain less than 2% of residual LDL receptor activity. Partial amelioration of hyperlipidemia has been achieved in some homozygous deficient patients by diverting the portal circulation through a portacaval anastomosis (3) and by chronic plasmapheresis therapy (4). A more direct approach has been to correct the deficiency of hepatic LDL receptor by transplanting a liver that expresses normal levels of LDL receptor. Three patients that survived this procedure normalized their serum LDL-cholesterol (5-9). We have used an authentic animal model for FH, the Watanabe Heritable Hyperlipidemic rabbit (WHHL), to develop gene therapies for the homozygous form of FH (10-13). The WHHL rabbit has a mutation in its LDL receptor gene which renders the receptor completely dysfunctional (12) leading to severe hypercholesterolemia, diffuse atherosclerosis, and premature death. The potential efficacy of gene therapy for FH is supported by a series of studies we have performed in the WHHL rabbit in which we have achieved metabolic improvement (14-18). Liver tissue was removed from WHHL rabbits and used to isolate hepatocytes and establish primary cultures. A functional rabbit LDL receptor gene was transduced into a high proportion of hepatocytes using recombinant retroviruses, and the genetically corrected cells were transplanted into the animal from which they were derived. Transplantation of the genetically corrected, autologous hepatocytes was associated with a 30-40% decrease in serum cholesterol that persisted for the duration of the experiment (4 months, Ref. 18). Recombinant derived LDL receptor RNA was detected in liver for at least 6 months. There was no apparent immunological response to the recombinant derived LDL receptor.(ABSTRACT TRUNCATED AT 400 WORDS)

Short-term synchrony of motor unit discharge during weak isometric contraction in Parkinson's disease

Short-term synchrony between the discharges of motor units has been assessed in Parkinson's disease (PD) and normal man. The discharges of single motor units were recorded in the extensor digitorum communis (EDC) muscle of the forearm or the tibialis anterior (TA) muscle of the leg during weak, voluntary isometric contraction. Short-term synchrony was defined as a narrow peak (total width less than 25 ms) in cross-correlograms constructed from the discharges of pairs of motor units. There was no difference in the incidence of short-term synchrony between PD and normal age-matched subjects for either the EDC or TA muscle. On average, 60% of pairs of motor units exhibited synchrony, but this varied between 0% and 100% for both groups. The amount of short-term synchrony was assessed as the probability (above chance) of discharge of one motor unit with respect to the other. In TA, but not EDC, this index was greater for PD than for normal subjects. The high indices of synchrony in TA in PD were not related to lower discharge rates of motor units. Parkinson's disease subjects, but not normal subjects, also showed broad correlations that were invariably associated with periodic discharges in the range 4-6 Hz. In some instances, a peak of short-term synchrony was observed superimposed on the broad correlation. The periodic correlograms were often associated with overt tremor which accompanied the contraction. Motor units occasionally discharged paired impulses (doublet discharges) with short interspike intervals of 5-15 ms (normal and PD) or, as a more persistent feature in PD, longer interspike doublets (20-60 ms) associated with periodic synchrony (4-6 Hz). The abnormal discharge characteristics of motor units are discussed in relation to the bulbospinal control of presynaptic drive to motor neurons in PD.

Analysis of human TSH receptor gene and RNA transcripts in patients with thyroid disorders

Human TSH receptor (hTSH-R) gene and RNA transcripts were analyzed by Southern and Northern blots in patients with various thyroid disorders, and in tissue cell lines. A 1.4 Kb cDNA encoding the extracellular human TSH-R domain was used as a probe. Southern analysis revealed two constant bands of 11.0 and 5.0 Kb (hTSH-R) in the thyroid and human white cell samples studied, regardless of the disease process. Northern analysis showed a predominant band at about 4.4 Kb in the thyroid tissues but not in non-thyroid tissue or cell lines tested. There were no gene rearrangements or abnormal transcripts in Graves' disease or multinodular goiter samples. In contrast, the labelled cDNA TSH-R probe did not bind to RNA isolated from 1 of 2 papillary cancer samples. A portion of the unique area of the h-TSH receptor (approximately nucleotides 1100-1230) was directly sequenced in thyroid glands from patients with Graves' disease, multinodular goiter, and differentiated thyroid cancer. No mutations or polymorphisms were identified in these samples, as compared to normal thyroid or control placenta, although further definition of sequence variation in other areas of the TSH receptor, as well as in more samples, needs to be performed. The present study indicates the normal patterns of DNA and RNA hybridization in a variety of thyroid tissues and disease states, and demonstrates that pathologic thyroid samples, with the possible exception of thyroid cancer, were not associated with specific nucleotide abnormalities in the unique area of the TSH receptor that was studied.

Natural killer cell activity from pregnant subjects is modulated by RU 486

Natural killer cells form an integral component of the body's innate immune system. Natural killer cell activity is reduced during pregnancy, especially in the latter half. To investigate the role progesterone may play in immunomodulating natural killer cell activity during pregnancy, we evaluated the effect of RU 486 on natural killer cells isolated from pregnant subjects. Natural killer cell activity was measured with an 18-hour, Chromium 51 release, microcytotoxicity assay with K-562 cells as target cells. We demonstrated that RU 486, in a concentration range from 5 to 40 mumol/L, augmented natural killer activity threefold to fivefold over baseline. This augmentation of activity was suppressed to baseline by the addition of excess progesterone. The addition of hydrocortisone resulted in an insignificant reduction in this augmented activity. This study suggests that progesterone may play a role as an immunomodulating factor in maternal acceptance of the fetal allograft.

Long-term improvement of hypercholesterolemia after ex vivo gene therapy in LDLR-deficient rabbits

Familial hypercholesterolemia (FH) is an inherited disorder in humans that is caused by a deficiency of low density lipoprotein receptors (LDLRs). An animal model for FH, the Watanabe Heritable Hyperlipidemic rabbit, was used to develop an approach for liver-directed gene therapy based on transplantation of autologous hepatocytes that were genetically corrected ex vivo with recombinant retroviruses. Animals transplanted with LDLR-transduced autologous hepatocytes demonstrated a 30 to 50 percent decrease in total serum cholesterol that persisted for the duration of the experiment (122 days). Recombinant-derived LDLR RNA was harvested from tissues with no diminution for up to 6.5 months after transplantation.

Effect of task on the degree of synchronization of intrinsic hand muscle motor units in man

1. Recordings were made of the firing of pairs of intrinsic hand muscle motor units active under different task conditions in man. The different tasks were defined as isometric contractions producing force in one of three different directions: finger abduction, finger extension, or finger flexion. The degree of motor-unit synchronization associated with each of these task conditions was compared with the use of cross-correlation analysis. 2. The average amount of synchronization between the firing of motor units recorded from within first dorsal interosseous muscle (IDI) was greater during index finger extension than during index finger abduction (n = 8 motor-unit pairings, 3 subjects). In addition, for another sample population of motor units, the average amount of synchronization was greater during index finger abduction than during index finger flexion (n = 11 motor-unit pairings, 4 subjects). 3. In a further series of experiments, one motor unit of each pair was recorded from second dorsal interosseous muscle (2DI), whereas the other motor unit of each pair was recorded from 1DI. The average amount of synchronization for these motor-unit pairings was greater during extension of the index and middle fingers than during abduction of the index and middle fingers (n = 8, 4 subjects). For another sample population of such motor-unit pairings, the average amount of synchronization was found to be greater during abduction of the index and middle fingers than during flexion of the index and middle fingers (n = 11, 4 subjects). 4. In approximately one-third of cases, it was not found possible to maintain the same firing rates from two motor units in 1DI when active under different task conditions. For instance, the "reference" motor unit might consistently fire at a faster rate than the "response" motor unit when active during index finger extension but consistently fire at a slower rate than the response motor unit when active during index finger abduction. Where such motor-unit pairs have been studied in detail, the pattern of task dependence in their synchronization was found to be similar to that described above for motor-unit pairs in which the firing rates remained constant under the different task conditions.(ABSTRACT TRUNCATED AT 400 WORDS)

Influence of the pontine and medullary reticular formation on synchrony of gamma motoneurone discharge in the cat

Discharges of gamma motoneurones were recorded from cut filaments of the nerve to the gastrocnemius medialis muscle in the cat decerebrated at an intercollicular level. Gamma motoneurones exhibited a background discharge in the absence of intentional stimulation, or could be made to discharge by continuous, innocuous stimulation of the skin of the heel. The discharges were periodic and regular (low coefficient of variation of interspike intervals), and no correlation was observed between the discharges of pairs of individual gamma efferents. Electrolytic lesion of the ipsilateral pontine and medullary reticular formation in the nucleus subcoeruleus, the nucleus reticularis gigantocellularis or the nucleus reticularis magnocellularis, invariably decreased regularity of discharge and resulted in short term synchrony. Lesions of the peri-aqueductal grey, the nucleus raphe dorsalis or the midline raphe nuclei did not induce synchrony. Surgical lesions in the locus coeruleus caused irregular firing and synchrony only when the lesion extended into the adjacent nucleus subcoeruleus. We conclude that monoaminergic neurones of the nucleus subcoeruleus, or a closely associated tegmental field, with axons descending through the gigantocellularis and magnocellularis fields, are the most likely origin of the bulbospinal control of synchronizing influences on gamma motoneurone discharge.

The immunopathogenesis of AIDS

In summary, the understanding of the pathogenesis of immune dysfunction in HIV infection is incomplete. New mechanisms by which HIV disrupts the immune system through alterations in basic biochemical events in CD4 T cells are continually being discovered. In a positive light, because of the complexity involved in HIV-mediated induction of immune suppression, logic suggests there is potential for reversing some of these processes.

Significance of variation in turnover of glycated albumin on indices of diabetic control

We measured the half-time of disappearance of 125I-labelled glycated albumins in a rat model of diabetes with continuous infusion of physiological saline and insulin. Our results indicate that (i) in non-diabetic rats, continuous infusion of saline per se did not affect the concentrations of glucose or of fructosamine, and the half-time of disappearance of albumin was unaffected by degree of glycation; (ii) hyperglycaemia (mean plasma glucose concentration of 18-27 mmol/l) caused a small but significant increase in half-time of labelled glycated albumin disappearance from a mean of 42 h to a mean of 47 h; (iii) this effect of hyperglycaemia outweighed any effect of increase in albumin excretion detected in poorly controlled diabetic rats without infusion. We conclude that the effect of hyperglycaemia in slowing turnover of glycated albumin is likely to be insignificant in relation to its effect in promoting glycation, and may be species-dependent. However, in nondiabetics, variation of turnover of glycated albumin may well be significant in explaining the wide interindividual variation in concentration of glycated protein.

Specificity of the low density lipoprotein-glycosaminoglycan interaction

There is ample documentation of the binding of chondroitin sulfate/dermatan sulfate proteoglycans to low density lipoprotein (LDL) both in vivo and in vitro. The interaction of these two species may be an early and important step in atherogenesis. Therefore, there is interest in defining the features of both molecules that are critical for their interaction. We employed a recently described competitive microassay that measures initial binding of proteoglycan to immobilized LDL. We confirmed the work of others that it is the apolipoprotein B component and, at least in part, a heparin-binding domain of LDL that are responsible for binding chondroitin sulfate/dermatan sulfate proteoglycans. The principal thrust of our study was concerned with the effects of a glycosaminoglycan's degree of sulfation on the binding to LDL. Initial experiments comparing dermatan sulfate and chondroitin sulfate proteoglycans indicated that the former was more efficient at binding LDL than the latter and that oversulfation, rather than chain length or iduronate content, was the preeminent feature involved. Additional binding studies with dermatan sulfate, chemically sulfated chondroitin-4-sulfate, and naturally occurring oversulfated chondroitin sulfates indicated that the degree of sulfation, not the position of sulfation, determined affinity for LDL. These results suggest that studies should be undertaken to determine whether oversulfated segments of glycosaminoglycans are especially involved in associations with LDL, leading to lipid accumulation, in the artery wall.

Absence of retroviral sequences in Graves' disease

An earlier report of HIV-1 gene sequences in thyroid cell genomic DNA from patients with Graves' disease prompted use of the polymerase chain reaction technique to identify such sequences in Graves' disease thyroid tissue and in white blood-cells from these patients. We were unable to confirm the existence of HIV-1-related DNA sequences in Graves' specimens.

Correlation between the discharges of motor units recorded from the same and from different finger muscles in man

1. Cross-correlation analysis of the discharges of individual motor units recorded from various different finger muscles has been performed during weak, isometric, voluntary contractions in man. 2. The dominant feature in 88% of the cross-correlograms studied was a narrow, central peak, the area of which significantly exceeded that expected for independent processes (P less than 0.001). The highest bin counts in these central peaks were mostly within 5 ms of time zero in the histograms, and the base of these peaks extended between 5 and 31 ms (modal value = 13 ms with 90% of the values lying between 8 and 18 ms). The width and displacement of the central cross-correlogram peaks were similar irrespective of whether the contributory spike trains were recorded from motor units active in the same finger muscle or recorded from motor units in different, co-activated finger muscles. 3. The time course of the central peaks in this study was found to be consistent with the hypothesis that it is generated by the joint occurrence of EPSPs evoked in motoneurones by branches of common stem presynaptic fibres using the theoretical model developed by Kirkwood (Kirkwood & Sears, 1978). The model parameters providing the best fit with our experimental data imply that synaptic contacts on motoneurones made by these common inputs lie on average peripherally in the dendritic tree and generate small (less than 300 microV) EPSPs superimposed on a high level of background synaptic noise. 4. Minima (troughs) were found either side of the central peak in 27% of the cross-correlograms studied, and their appearance was invariably associated with a large central peak. These secondary features could not be modelled with the same operator parameters that describe the central peaks. Their presence was particularly noticed in association with very regular discharges from the output motoneurones. 5. Smaller and broader secondary peaks symmetrically displaced 30-55 ms either side of the large, narrow central peak were observed in 7% of the cross-correlograms studied. We suggest that these secondary features which were found at lags shorter than the interspike interval of the contributory motor unit spike trains reflect the autocorrelation functions of the spike trains of common input fibres. On this basis the observed displacement of these secondary peaks from the primary feature in the cross-correlogram indicate firing rates for common input fibres in the range 18-33 impulses s-1. 6. In a small number of cases (1.4%) the cross-correlogram was flat and indistinguishable from the results of cross-correlating independent spike train data.

Variation in the degree of synchronization exhibited by motor units lying in different finger muscles in man

1. Cross-correlation analysis was performed on the discharges of motor units recorded from the same or from different finger muscles during weak, voluntary isometric contractions in man. 2. In 88% of cases such cross-correlograms contained a narrow central peak indicating synchronization between the firing of the contributory motor units. Expressed in terms of the synchronization index, b (peak area/total number of reference plus response spikes) the amount of synchronization found in these different recordings ranged from b = 0.0057 to b = 0.1436 (n = 1230). The duration of the synchronization (measured across the base of the peak) ranged from 5 to 31 ms (mode = 13 ms). 3. For each pair of motor units examined the amount of synchronization between their firing varied from minute to minute of a long recording. In around half the cases studied this variation appeared to correspond to variation in the firing rates of the two motor units whereas in the other half of cases tested no relationship was found between the firing rates and the amount of synchronization. 4. Some motor unit pairings consistently showed more synchronization than other motor unit pairings within the same muscle. A frequency histogram of the synchrony measurements from all of the motor unit pairings tested in that muscle showed a unimodal and continuous distribution. 5. Some subjects consistently showed two or three times more motor unit synchronization than others in equivalent recordings. This rank order of motor unit synchronization in different subjects was found to be the same in all muscle pairings tested. 6. A similar distribution in the amount of motor unit synchronization found in different muscle pairings was found in all subjects tested. In the first place the firing of motor units which act on widely separated fingers was less synchronized than the firing of motor units acting on adjacent fingers. Secondly, motor units acting on the lateral fingers (thumb, index) showed less synchronization in their discharges than motor units acting on medial fingers (ring, little). Finally the firing of motor units in the finger flexor muscles were less synchronized than the firing of motor units in either the finger abductor or the finger extensor muscles. 7. The synchronization of motor unit activity in different muscles indicates the presence of a widespread projection pattern for the branches of some last-order input fibres to finger muscle motoneurones.(ABSTRACT TRUNCATED AT 400 WORDS)

Thyroid stimulating and thyrotrophin binding-inhibitory immunoglobulin activity in patients with systemic lupus erythematosus having thyroid function abnormalities

In order to determine whether thyroid function abnormalities seen in patients with systemic lupus erythematosus (SLE) are associated with autoantibodies directed against the TSH receptor, 28 patients with SLE who demonstrated abnormal thyroid function tests were evaluated for the presence of anti-TSH receptor antibodies. Anti-TSH receptor antibody activity was evaluated by assessing cAMP production in vitro in FRTL-5 (rat thyroid) cells (TSI) and the ability of the subjects' IgG to block the binding of thyrotrophin to its receptor in vitro (TBII). Complete thyroid function tests, including TRH testing, also were performed. Ten of the 28 patients demonstrated TSI activity, ranging from 133% to 183% of control. Five patients also had evidence of TBII activity, ranging from 22% to 90% inhibition (of control TSH binding levels), with 2 patients having evidence of both types of antibodies. Neither the TSI nor TBII activity in these patients was associated with the abnormal thyroid function tests. However, there were significantly more patients with TBII activity who had elevated TSH levels (3 of 4 vs 1 of 24, p less than 0.05), suggesting a potential physiologic response to TSH receptor blockade. These results indicate that patients with SLE and thyroid function abnormalities can demonstrate TBII and TSI activity in their serum. However, these antibodies do not necessarily correlate with specific abnormalities of thyroid function.

An unsulphated region of the rat chondrosarcoma chondroitin sulphate chain and its binding to monoclonal antibody 3B3

The chondroitin sulphate chains of proteoglycans are not uniformly sulphated. Commonly, regions of under- and over-sulphation are found. It is probable that variability in chondroitin sulphation has physiological significance, although such structure-function relationships largely remain unexplored. Chondroitin sulphate from rat chondrosarcoma proteoglycan has been found to possess no oversulphated residues. It is primarily chondroitin 4-sulphate, although a significant proportion of unsulphated disaccharides (14%) are also present. It appears that some unsulphated disaccharides are concentrated only at the point of attachment to the linkage region (i.e. it is the major unsaturated disaccharide remaining attached to chondrosarcoma proteoglycan core produced by chondroitinase ABC digestion). This proteoglycan core binds monoclonal antibody (MAb) 3B3. Although 3B3 principally binds to 6-sulphated 'stubs' of proteoglycan cores [Couchman, Caterson, Christner & Baker (1984) Nature (London) 307, 650-652], given a high concentration of unsulphated 'stubs', it can alternatively bind to these residues. It is also evident that caution must be exercised in using MAb 3B3 to identify chondroitin 6-sulphated proteoglycans.

Fructosamine compared with a glucose load as a screening test for gestational diabetes

Five hundred seven women were screened for gestational diabetes between 20-36 weeks' gestation. All received a 100-g glucose (polycose) load at 28 weeks with measurement of plasma glucose 1 hour later. Fructosamine levels were measured at 4-week intervals from 20-36 weeks. At 36 weeks, a full 100-g 3-hour glucose tolerance test was performed on all subjects. Eighteen women were diagnosed as having gestational diabetes. The glucose load had a sensitivity of 81% in detection of gestational diabetes, compared with 50% for fructosamine at 36 weeks. Fructosamine is not useful as a screening test for gestational diabetes as currently defined.

Effects of beta-D-xyloside on morphogenesis and cytodifferentiation in cultured embryonic mouse molars

Embryonic mouse molars were grown on a semi-solid medium supplemented with 2 mM beta-D-xylopyranoside (beta-xyloside), a specific inhibitor of proteoglycan synthesis. The induced glycosaminoglycan depletion in the extracellular matrix was monitored by immunohistochemistry employing monoclonal antibodies to chondroitin 4- and chondroitin 6-sulfates. beta-Xyloside inhibited formation of the dental bell and delayed the appearance of the first odontoblasts. Odontoblast functional differentiation proceeded in the absence of chondroitin sulfate in the basement membrane. Predentin secreted in the presence of beta-xyloside triggered the polarization of ameloblasts, but did not allow the maintenance of polarized odontoblasts. These results support the hypothesis that, in the tooth germ, chondroitin sulfate proteoglycans participate in the regulation of cell kinetic-dependent morphogenesis (Mark et al., 1990. Differentiation 43, 37-50). On the other hand, the possibility that chondroitin sulfate might play a role in odontoblast terminal differentiation is definitively ruled out.

Transplantation in the military: state of the art--a progress report from the Army-Navy Transplant Program

The commitment to clinical transplantation services by the Army and Navy is now in its third decade. Located at the Walter Reed Army Medical Center, the Army-Navy Organ Transplant Service has been staffed and led by some of the most prominent transplant surgeons in America. Military beneficiaries are eligible for evaluation and care regardless of their geographic assignment or residence. Principally a renal transplant clinical service, the Organ Transplant Service also gives support to patients with heart, liver, and pancreas grafts. Organs for transplant are largely (85%) from the civilian sector, although the Department of Defense has officially encouraged organ donation. Research, scientific publication, protocol development, teaching, and interaction with reserve components have been major facets of the Organ Transplant Service. Clinical outcome in renal transplantation at the Army-Navy Unit is comparable to that at the best civilian units: 2-year graft and patient survival 81% and 98%, respectively. These superior clinical results and the major roles that the Army-Navy Transplant Service have played make continued support and expansion of military transplantation compelling.