Standard NIH Research Articles

The effect of maternal exposure to flaxseed on spermatogenesis in F 1 generation rats

Pregnant Sprague–Dawley rats were exposed to a flaxseed (20 or 40%), flaxmeal (13 or 26%) or standard NIH AIN-93 (0% flaxseed control) diet throughout gestation and until their offspring were weaned. After weaning, F 1 generation males were placed in the same diet treatment groups as their mothers for 70 days. Statistically significant differences were not observed between either low-dose or high-dose flaxseed and flaxmeal-treated animals and the 0% flaxseed control animals for testis weights, homogenization resistant spermatid counts, daily sperm production rates, epididymal weights, seminal vesicle weights, seminiferous tubule fluid testosterone concentrations and the percentage of sperm abnormalities. The following statistically significant differences were observed when treated groups and the 0% flaxseed control groups were compared: (1) increases in serum LH in the 20% and 40% flaxseed treatment groups and in serum LH and testosterone in the 26% flaxmeal treatment group; (2) increases in the cauda epididymal weight from the 20% and 40% flaxseed groups; (3) increases in cauda epididymal sperm numbers/g epididymis from the 20% and 40% flaxseed and the 13% and 26% flaxmeal treatment groups; (4) a decrease in prostatic weight from the 20% flaxseed and 13% and 26% flaxmeal treatment groups. Prostate weight in the 40% flaxseed treatment group was lower but not statistically significantly different than the 0% flaxseed control group. Histological effects on spermatogenesis were not observed in either the control group, flaxmeal or the flaxseed treated groups.

The association between human leucocyte antigens (HLA) and mortality in community residents aged 85 and older.

The association between Human Leucocyte Antigens (HLA) and aging was investigated. It is possible that HLA antigens are associated with longevity, either indirectly through disease associations or directly through involvement in the aging mechanism. Community-based follow-up study. Leiden, the Netherlands. A total of 919 subjects were HLA typed in this community-based study. All subjects were aged 85 and older and were white. Seventy-two percent of the cohort was female. Age- and sex-adjusted Mortality Rate Ratios (MRR) were estimated for 79 antigens by the subject-years method. HLA-A, -B and -C typing was performed with the standard NIH lymphocytotoxicity test, HLA-DR and -DQ typing was performed with the two-color fluorescence test. Homozygosity for HLA-A, -B, and -DR was defined as only one detectable antigen at a locus. The mean follow-up period (SD) was 5.0 (0.6) years. At the end of the follow-up, 70% of the subjects had died. The MRR (95% CI) for B60 was 0.96 (0.75-1.23), and for DR11 it was 0.82 (0.66-1.01). For A2 and A26 only, the MRR (95% CI) was significantly different from 1: 0.85 (0.73-0.99), P = .04 and 1.45 (1.06-1.99), P = .02, respectively (P values not corrected for the number of antigens tested). Homozygosity was not associated with mortality. HLA was not associated with mortality after the age of 85. Therefore, direct involvement of HLA in aging is unlikely. We suggest that the findings of previous studies are attributable to methodological shortcomings such as small sample size and differences in genetic background of the subjects.

Intrathecal humoral immune response in HAM/TSP in relation to HLA haplotype analysis.

In HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), we correlated human leukocyte antigen (HLA) haplotypes to the fine specificities of intrathecally synthesized IgG antibodies against HTLV-1. HLA haplotypes of HAM/TSP patients were determined by the standard NIH microcytotoxicity test and family HLA studies. IgG antibodies against HTLV-1 synthetic peptides in paired CSF and serum were measured by enzyme immunoassay, and intrathecal synthesis of antibodies was evaluated. HAM/TSP patients with particular HLA haplotypes (A24Cw7B7DR1DQ5, A2Cw7B7DR1DQ5, A24Cw-B52DR15DQ6, A11Cw1B54DR4DQ4, and A24Cw1B54DR4DQ4) showed more frequently intrathecal synthesis of antibodies against HTLV-1 synthetic peptides, especially against HTLV-1 env gp21 synthetic peptides. In HAM/TSP, a retrovirus-induced human chronic inflammatory disease of the CNS, this is the first report to provide evidence that the intrathecal antiviral immune response is influenced by immunogenetic factors of the HLA complex.

HLA antigens and asthma in Greeks

HLA-A and -B antigens were determined in a group of 76 Greek asthmatic patients: 35 children (1·5–15 years) and 41 adults (18–73 years). The results were compared to those of 400 healthy unrelated controls from the same population. The standard NIH lymphocytotoxicity test was applied. When all 76 patients were compared to the controls, a statistically significant lower frequency of HLA-B5 and -B35 antigens was noted. When adults were analysed alone, an increased frequency of HLA-B8 was found. On the other hand, in the asthmatic children sub-group, the HLA-A10 antigen was significantly higher and the HLA-B5 was significantly lower than in the controls. These data imply that different HLA antigens may be involved in the pathogenesis of several clinical forms of asthma and that, in order to study the role of immunogenetic factor(s) in the pathogenesis of this disease, more adequate grouping criteria are needed.

Solubilized HLA class I antigen enzyme-linked immunoassay to identify HLA-typing reagents

The objective of this study was to evaluate the use of sHLA in a solid-phase EIA as a rapid and sensitive way to identify potential IgG HLA class-I-typing reagents. To evaluate the efficacy of the sHLA EIA, we used the assay to screen 259 HLA-A, -B, and -C antisera that our laboratory had procured using the standard NIH LCA. A positive result obtained by the sHLA EIA, which was defined as an EIA ratio of 3 SD above the mean of 91 anti-HLA-negative sera, revealed that 91% (79 of 87) of the A-locus-typing reagents were positive, 96% (150 of 156) of the B-locus antisera were positive, and only 75% (12 of 16) of the C-locus reagents were positive. The typing reagents that were negative by EIA ( n = 18) fell into two categories. First, 38% (7 of 18) were negative by sHLA EIA, as they were IgM-typing reagents (NIH LCA reactivity ameliorated by DTT). The second group of the 11 remaining typing reagents had a mean EIA ratio of 1.0 ± 0.246 (mean ± 1 SD), which was significantly ( P < 0.001) higher than the mean of the 91 negative controls that were used to establish the negative cutoff. The overall sensitivity of the sHLA EIA to detect HLA class-I-directed IgG was 97.2%.

A one‐step monoclonal antibody typing procedure that simplifies HLA class I and class II typing

We have developed monoclonal antibodies to most HLA specificities, making it possible for us to devise a simple, rapid, one-step microcytotoxicity test. The test is performed by adding 1 microliter of cells to 1 microliter of antibody-complement mixture predotted on the microtest tray. The reactions are read following a 1-hour incubation period (30 minutes in some instances). The analysis of reactions seen on testing 105 class I antibodies and 50 class II antibodies is shown. A comparison of typing by the standard NIH method and the new one-step procedure showed a > 96% concordance in the 500 T cells and 200 B cells we examined. Class I and class II typing could be performed using B cells, thus obviating the need to isolate both T and B cells for HLA typing.

POSITIVE PRETRANSPLANT CROSSMATCHES PREDICT EARLY GRAFT LOSS IN LIVER ALLOGRAFT RECIPIENTS

We evaluated the influence of donor-recipient HLA compatibility and recipient pretransplant antidonor sensitization on liver allograft recipient survival. The overall graft survival results for 67 cyclosporine-prednisone treated liver allograft recipients at 3, 6, and 12 months posttransplant were 86%, 83%, and 83%, respectively. No significant differences were observed when comparing the one-year survivals of 81% vs. 85% for men and women or 80% vs. 85% for adult and pediatric patients. Similarly, no differences were observed when comparing one-year graft survivals for well vs. poorly matched recipients of 77% vs. 83% for recipients with < or = 2 HLA A, B vs. > 2 HLA A, B mismatches (MMs) and 82% vs. 82% for recipients with 0-1 HLA-DR MMs vs. 2 HLA-DR MMs, respectively. Pretransplant transfusion history and race also did not influence survival. Standard NIH (long-incubation) and anti-human globulin (AHG) crossmatches were performed. The 12% of recipients (8/67) displaying a positive NIH crossmatch experienced significantly poorer 3-, 6-, and 12-month survivals of 62% vs. 89%, 62% vs. 86%, and 62% vs. 86% (all P < 0.05), respectively, than the 59 NIH-crossmatch negative recipients. Similarly, the 16% (11/67) of recipients displaying a positive AHG crossmatch had significantly poorer 3-, 6-, and 12-month survivals of 63% vs. 91%, 54% vs. 89%, and 54% vs. 89% (all P < 0.05) respectively, than the 56 AHG crossmatch-negative recipients. NIH and AHG crossmatch-positive sera were treated with dithioerythritol (DTE) to establish whether reactivity was due to IgM or IgG immunoglobulin. One-year graft survivals of 65% vs. 30% (P < 0.05) were observed when the crossmatch-positive sera reactivities were due to IgM vs. IgG immunoglobulin. While graft survivals were improved when positive crossmatch serum reactivity was due to IgM, these survivals were still significantly poorer than when the crossmatches were completely negative (86% vs. 60%, P < 0.05 for NIH-negative vs. NIH-positive, but DTE-negative, and 88% vs. 77%, P < 0.05 for AHG-negative vs. AHG-positive, but DTE-negative). Therefore, an NIH- or AHG-positive crossmatch, due either to IgM or IgG reactivity, results in poor early (3- and 6-months) liver allograft survival. Crossmatch-positive recipients experienced significantly (P < 0.05) more rejections and more steroid-resistant rejections (P < 0.05) than crossmatch-negative recipients.(ABSTRACT TRUNCATED AT 400 WORDS)

AHG AND DTE/AHG PROCEDURE IDENTIFICATION OF CROSSMATCH-APPROPRIATE DONOR-RECIPIENT PAIRINGS THAT RESULT IN IMPROVED GRAFT SURVIVAL

We compared our standard NIH (extended incubation) crossmatch (XM) with antihuman globulin (AHG) and flow cytometry crossmatches (FCXM) and correlated the results with primary cadaveric and retransplant graft survivals. In addition, we treated the XM sera with the reducing reagent dithioerythritol (DTE) to discriminate IgM from IgG immunoglobulin reactivity. For the 166 CsA-Pred-treated primary cadaveric renal allograft recipients the 1-year graft survival rate following an NIH-NEG XM was 81%. NIH-XM-NEG recipients who were also AHG-XM-NEG displayed an 82% 1-year graft survival as well. In contrast, NIH-NEG, but AHG-POS XM primary CAD recipients displayed a significantly reduced graft survival rate of 67%. Treatment of AHG-POS XM sera with DTE-delineated DTE/AHG-NEG and POS crossmatches associated with significantly different graft survivals of 83% and 0%, respectively, for these primary recipients. Flow cytometry XM results did not improve on the AHG-NEG or DTE/AHG-NEG XM primary graft survivals. These results were seen whether testing pre-Tx or historical (Hx) sera. For Re-Tx recipients an AHG-NEG XM resulted in significantly improved graft survival compared with the NIH-XM-NEG results. The overall 1-year graft survival rate for the 70 Re-Tx recipients studied was 64% (following a NEG pre-Tx NIH-XM). Re-Tx recipients with an AHG-NEG XM displayed an improved graft survival compared with NIH-XM-NEG recipients (77% vs. 64%, P less than 0.05) and with AHG-POS recipients (77% vs. 36%, P less than 0.01). However, treatment of Re-Tx, AHG-POS sera with DTE resulted in comparably poor graft survival rates of 31% and 50% for DTE/AHG-NEG and POS crossmatches, respectively. A FCXM did not improve on the results of Re-Tx graft survival following an AHG-NEG XM. These results were obtained whether testing pre-Tx or Hx sera. HLA matching, PRA, and the time the first Tx was lost did not influence the Re-Tx graft survival outcome following an AHG-NEG XM. Therefore, successful primary cadaveric renal allograft survival can be accomplished following either an AHG-NEG XM or an AHG-DTE-NEG XM. Re-Tx graft survival is significantly improved following an AHG-NEG XM. Re-Tx recipients with an AHG-POS XM who are either DTE/AHG-POS or -NEG display reduced graft survivals compared with AHG-NEG Re-Tx recipients.

HLA antigens and bronchogenic carcinoma in the Greek population.

The distribution of HLA antigens was studied in 85 Greek patients with bronchogenic carcinoma. Fifty-seven specific HLA antisera were used to determine 27 HLA-A and B antigens, with the two-stage standard NIH microlymphocytotoxicity assay. The results were compared with those in a control group, consisting of 400 healthy individuals. In the whole group of patients there was a significantly higher frequency of HLA-AW19 and HLA-A29 (p less than 0.003 and p less than 0.006 respectively) and a lower frequency of HLA-A2 and HLA-A3 (p less than 0.014 and p less than 0.006 respectively) than in the control population. In patients with squamous cell carcinoma there was a significantly higher frequency of HLA-AW19 and lower frequency of HLA-A2 (p less than 0.02 and p less than 0.05 respectively). In small cell carcinoma patients there was a significantly lower frequency of HLA-A3 (p less than 0.04) than among the controls. In patients with adenocarcinoma no significant change of HLA antigen frequencies was observed when compared to the controls.

Purified chick-embryo-cell (PCEC) rabies vaccine: its potency performance in different test systems and in humans

The potency of purified chick embryo cell rabies vaccine Rabipur was evaluated by four different in vivo test systems: (1) NIH test with homologous strain LEP challenge; (2) intramuscular challenge of vaccinated laboratory animals; (3) postexposure vaccine treatment trials in laboratory animals; and (4) antibody induction tests in laboratory animals. These different test systems were compared with the Standard NIH test and an in vitro test, the modified ABT. Each of the four in vivo methods chosen demonstrated potency values superior to that of the Standard NIH test in which challenge was with CVS strain. Potency relations were: Standard NIH test versus alternative methods versus modified ABT 1.0-2.2-1.85 respectively. There was good correlation between alternative in vivo methods and the ABT. In addition examples of antibody induction in man following administration of various postexposure treatment regimens are presented which lead to the conclusion that postexposure vaccination method and composition of the study group play a more important role in achieving optimum treatment results than vaccine potency, provided that it corresponds to WHO requirements (minimum 2.5 IU per dose).

IMPROVED GRAFT SURVIVAL FOR FLOW CYTOMETRY AND ANTIHUMAN GLOBULIN CROSSMATCH-NEGATIVE RETRANSPLANT RECIPIENTS

We compared our standard NIH (extended incubation) crossmatch (XM) with antihuman globulin (AHG) and flow cytometry XMs and correlated the results with rejection episodes and graft survivals. For 89 CsA-Pred, primary renal allograft recipients, AHG and/or FCXM results did not improve on the NIH-XM-negative (NEG) graft survival results, whether testing pretransplant or historical (Hx) sera. Similarly, there was no association of a positive (POS) AHG or FCXM with increased rejection episodes in these primary recipients. However, for retransplant (Re-Tx) recipients a neg AHG or FCXM did discriminate fewer rejections and an improved graft survival compared with the NIH-XM-neg. results. The overall one-year graft survival for the 47 Re-Tx recipients studied herein was 66% (based on a neg pre-Tx NIH-XM). Pre-Tx AHG-NEG, Re-Tx recipients displayed an improved graft survival compared with NIH-XM NEG recipients (77% vs. 66%, P less than 0.05) and with AHG-POS recipients (77% vs. 47%, P less than 0.05). Similarly, pre-Tx, FCXM-NEG, Re-Tx recipients displayed improved graft survivals compared with NIH-XM-NEG recipients (83% vs. 66%, P less than 0.05) and FCXM-POS recipients (83% vs. 48%, P less than 0.05). Re-Tx recipients displaying a POS AHG and/or FCXM experienced a significantly greater number of rejections than NEG-XM recipients (P less than 0.05, respectively). The AHG and FCXM results correlated with rejections and graft survivals whether testing pre-Tx or Hx high-PRA sera. Re-Tx recipients who were AHG-XM-NEG but FCXM-POS, experienced more rejection episodes than recipients who displayed a negative XM reactivity for both AHG and FCXM (P less than 0.02), but with no resulting differences in graft survival. HLA matching, pre-Tx blood transfusions and PRA did not impact on these crossmatch and graft survival results. Use of AHG and/or FCXMs for Re-Tx, but not primary, recipients should help to improve graft survival for these high-risk recipients.

80 HEPATITIS B VIRUS (HBV) CARRIER STATE AND HLA ANTIGENS IN 13 ITALIAN FAMILIES

The rate of HBV persistence in the families of our patients affected by Chronic Hepatitis B is much higher (72%) than the chronicity rate reported in the Italian population (10%). AIMS: in order to investigate the possible influence of the major histocompatibility complex upon the course of Hepatitis B infection through a regulation of the host's immune response, we studied the phenotype frequencies of HLA class I and class II antigens in some families. PATIENTS and METHODS: 13 families were studied (56 subjects: 26 parents and 30 children). They all have been infected by HBV: 40 have been positive for HBsAg for longer than 1 year, 16 seroconverted to HBsAb positivity. HLA antigens typing was performed using the standard NIH lymphocyte microlymphocytotoxicity technique. (NIH standard for A and B, NIH long for DR and DQ). RESULTS: DR4, whose protective role against virus persistence has been reported in the literature, is totally absent in our study-group, whereas its frequency in a population of 526 healthy Italian controls (matched for geographical origin) is 18.5%. We used Fisher's exact test to compare the frequencies of HLA determinants in the 40 chronic HBV carriers with those of the 16 seroconverted subjects. A possible protective role was found for DR2 (p= 0.0023), while a possible linkage with HBV persistence was found for A3 (p= 0.011) and B35 (p= 0.020). CONCLUSION: the absence of DR4 and DR2 and the presence of A3 and B35 could play a role in HBV persistence. Further studies are going on to confirm these data in a larger population.

The measurement of xylulose 5-phosphate, ribulose 5-phosphate, and combined sedoheptulose 7-phosphate and ribose 5-phosphate in liver tissue

A modification of the method of Kauffman et al. (F. C. Kauffman, J. G. Brown, J. V. Passonneau, and O. H. Lowry (1969) J. Biol. Chem. 244, 3647–3653) for the spectrophotometric determination of xylulose 5-phosphate, ribulose 5-phosphate, and combined ribose 5-phosphate and sedoheptulose 7-phosphate in tissue extract is presented. Using commercially available enzymes all three assays come to a clear endpoint with the assays described. Values for these metabolites in liver in three dietary states are reported; 48 h starved, ad libitum feeding of standard NIH rat ration, and meal feeding of a fat-free diet. Xylulose 5-phosphate values were 3.8 ± 0.3, 8.6 ± 0.3, and 66.3 ± 8.3 nmol/g. Ribulose 5-phosphate values were 3.4 ± 0.3, 5.8 ± 0.2, and 37.1 ± 5.3 nmol/g. Combined ribose 5-phosphate and sedoheptulose 7-phosphate were 29.3 ± 0.3, 38.2 ± 1.2, and 108.2 ± 14.5 nmol/g. The ratio of measured tissue content of [xylulose 5-phosphate]/[ribulose 5-phosphate] was found to be 1.12 ± 0.07 in starved animals, 1.48 ± 0.04 in ad libitum fed animals and 1.78 ± 0.03 in low-fat meal fed animals. These data are in good agreement with the range of equilibrium constants reported for this reaction, suggesting that the ribulose 5-phosphate 3-epimerase reaction (EC 5.1.3.1) is a near equilibrium reaction despite a more than 10-fold change in the tissue content of these metabolites.

The Effect of Dehydroepiandrosterone on Liver Metabolites

Liver metabolites and in vitro enzyme activities were measured in Sprague-Dawley rats pair-fed the standard NIH diet with or without 0.6% (wt/wt) dehydroepiandrosterone (DHEA) for 16 d. Absorption of DHEA from the gut was confirmed by a 300-fold increase in urine 17-ketosteroids in DHEA-treated animals. Of the liver metabolites measured only 6-phosphogluconate was significantly changed, increasing by less than a factor of two in the DHEA-treated animals, 38.7 ± 2.2 nmol/g, above the value in the pair-fed controls, 22.5 ± 2.5 nmol/g. Contrary to the in vitro findings that DHEA inhibits glucose-6-phosphate dehydrogenase (EC 1.1.1.49), thus leading to the hypothesis that DHEA inhibits fat synthesis by diminishing the availability of NADPH, the [NADP+]/[NADPH] ratios calculated from the 6-phosphogluconate dehydrogenase (EC 1.1.1.44), isocitrate dehydrogenase (EC 1.1.1.42) and malic enzyme (EC 1.1.1.40) redox couples were no more oxidized in the DHEA-treated animals than in the control animals. Malic enzyme and isocitrate dehydrogenase activities were 620 and 25% higher in DHEA-treated animals than in pair-fed controls. There was no change in the measured activity of glucose-6-phosphate dehydrogenase or 6-phosphogluconate dehydrogenase. These data give no support to the hypothesis that administration of DHEA per os results in decreased cytoplasmic NADPH in liver.

Priming procedure and hormone preparations influence rat granulosa cell response.

The FSH activity in equine (e) FSH, eLH, eCG, and ovine LH were examined and compared to that in the standard reference preparation NIH FSH-S13 by three types of assay: the FSH radioreceptor assay with rat testicular homogenate and the stimulation of plasminogen activator production and steroidogenic activity in granulosa cells from diethylstilbestrol (DES)- or eCG-primed donor rats. The difference in the two types of granulosa cells was that the eCG-primed cells have already acquired significant aromatase activity. With the exception of oLH, which showed very little FSH activity (approximately 0.03-0.08 X NIH FSH-S13) throughout the three assays, the equine gonadotropins exhibited great variations in activity with respect to each assay. eFSH, the most active molecule in these assays, had an activity of 44 X NIH FSH-S13 in the receptor binding assay, 8.75 X NIH FSH-S13 in plasminogen activator production, and 4-5 X NIH FSH-S13 in steroid production when assayed in the DES-primed granulosa cells. In the eCG-primed cells, eFSH showed an activity of 4.2 X NIH FSH-S13 in plasminogen activator production and 8.2 X NIH FSH-S13 in progesterone production. eLH had an activity of 10 X NIH FSH-S13 in FSH radioreceptor assay, but showed very little activity and behaved like oLH in stimulation of the cellular responses of DES-primed granulosa cells. However, when eLH was assayed in the eCG-primed cells, it did show stimulating activity with respect to the production of plasminogen activator and progesterone; however, the dose-response curves were not parallel to those of eFSH and eCG. eCG had much less FSH receptor-binding activity (0.29 X NIH FSH-S13) than eLH. It behaved like a LH molecule in DES-primed granulosa cells, but did show activity (approximately 1 X NIH FSH-S13) in stimulating the production of plasminogen activator and progesterone in eCG-primed granulosa cells. From these results, we conclude that under our culture conditions, neither eLH nor eCG was active in the DES-primed granulosa cells, but both were active in the eCG-primed cells, and that the choice of assay conditions and reference standards is very important. Different types of assay may give rise to completely different comparisons for the same molecules. The equine gonadotropins provide a particularly dramatic example of such differences.

Functional method for assessing oral perceptual skills in children.

An alternative method for assessing oral perceptual skills was developed to address some of the practical limitations of the standard form test. The alternate forms and standard NIH Oral Stereognostic Forms were administered to 182 children. Scores resulting from presentation of standard NIH forms and alternate edibles correlated .76. Suggestions for using the alternate forms for routine oral stereognostic testing are presented.

Improved detection of HLA-Cw5 and Cw7 by two colour fluorescence technique.

Reactivity of two Cw5 and three Cw7 antisera was compared in the standard NIH and the Two Colour Fluorescence (TCF) techniques. Contrary to the NIH, the TCF method yielded strong positive reactions which enabled clear assignment of the Cw5 and Cw7 specificities. The TCF technique combines three factors that increase the sensitivity of serum reactions: 1. typing on B lymphocytes, 2. prolonged incubation and 3. staining of the lysed cells with ethidium bromide.

An attempt to obtain a specific antiserum for in vitro immunological conditioning of bone marrow in acute non-lymphoblastic leukemia.

An antiserum was produced in rabbits to acute undifferentiated leukemia (AUL) antigens. Partial absorption of the antiserum allowed the removal of the cytotoxic activity against normal mononuclear cells of peripheral blood and bone marrow, in contrast to blast cells from acute and chronic leukemias, which were killed by the antiserum in a standard NIH cytotoxicity test. These observations suggest that antigens present on blast cells of AUL are also expressed on some acute and chronic leukemic cells and that these antigens could be interpreted as B or leukemia-associated antigens because of the disappearance of all cytotoxic activity of the immune serum after extensive absorption with B cells from chronic lymphoid leukemia.

Residual beta-cell function and islet cell antibodies in diabetic children.

Summary: There are no prospective studies evaluating residual β-cell function and islet cell antibody status during the first 2 years after the diagnosis of diabetes hi children. We report such a prospective study of 21 insulin-dependent diabetic children. The relationship of residual β-cell function during the 2 years after diagnosis, to age at diagnosis, islet cell antibody (ICA) status, histocompatability status, and exogenous insulin is reported. Twenty-one children were studied for at least 2 years after the diagnosis of diabetes. Blood was obtained at the time of diagnosis for the determination of ICA and histocompatability status. ICA status was determined 12 months after diagnosis, and again at 24 months if ICA had been detected at 12 months. Residual β-cell function was assessed serially by measuring 24-hr urinary C-peptide. The 24-hr C peptide excretion was expressed relative to 24-hr creatinine excretion. This ratio is termed urinary C peptide excretion (UCP). Islet cell antibodies were measured by indirect immunofluorescence on human O-group pancreas. Fluorescein-labeled anti-C3C was used to determine whether the islet cell antibodies were able to fix complement. A standard NIH micro-lymphocytotoxicity test was used to determine histocompatability status at the A, B, and C loci. Throughout the entire study period, the UCP of each diabetic was always below the mean of the group of nondiabetic children. For all diabetic children, the UCP decreased during the 24 months after diagnosis. Most children's (14 of 21) UCP had faUen below 0.20 during the 12 months after diagnosis. Twelve of 21 diabetic children were ICA positive at diagnosis. Five had unaltered titers of ICA 12 months later and four had no ICA detectable at 12 months, whereas for three the titer had fallen by at least two dilutions. The magnitude of the UCP 12 months after diagnosis correlated significantly with age at the time of diagnosis (r = 0.557; P < 0.05). Similarly, there was also a significant correlation between the UCP 24 months after diagnosis and age at diagnosis (r = 0.446; P < 0.05). There was no significant difference between insulin dose, expressed as units/kg/day at 12 and 24 months after diagnosis. There was no significant relationship between ICA status and insulin dose at 12 or 24 months. There was no discernible relationship between the evolution of ICA or UCP with histocompatability antigens at the A, B, or C loci. Speculation: The positive correlation between urinary C peptide and age at diagnosis of diabetes suggests that pancreatic size and potential for subsequent growth might be factors influencing the impact of a diabetogenic insult. For insulin-dependent children, the impact of the diabetogenic process is usually greatest during the 12 months after diagnosis. Potential therapeutic efforts to limit islet cell damage need to be applied early, and it is possible they may not need to be continued much beyond 12 months after diagnosis.

HLA – haplotypes investigations in the cases of /AGS/ adreno-genitale syndrome/ children and their parents

10 affected children /AGS/ and 3 healthy sibs from 11 families were typed for HLA-A and B antigens by the standard NIH lympho-cytotoxicity test. In one family two affected sibs shared both HLA haplotypes. Neither of the healthy sibs had HLA-haplotypes identical to the affected patients. As regards the individual HLA-types, B5/chi2=1,661/B7/chi2=0,062/, B40/ chi2=1,272/ seem to emerge as more frequent than the average, but with the population frequency based on 222 healthy blood donors' HLA-A-B antigen frequencies there was no significant difference.