Mapping of a gene for type 2 diabetes associated with an insulin secretion defect by a genome scan in Finnish families

Non-insulin dependent diabetes mellitus (NIDDM) affects more than 100 million people worldwide and is associated with severe metabolic defects, including peripheral insulin resistance, elevated hepatic glucose production, and inappropriate insulin secretion. Family studies point to a major genetic component, but specific susceptibility genes have not yet been identified-except for rare early-onset forms with monogenic or mitochondrial inheritance. We have screened over 4,000 individuals from a population isolate in western Finland, identified 26 families (comprising 217 individuals) enriched for NIDDM and performed a genome-wide scan using non-parametric linkage analysis. We found no significant evidence for linkage when the families were analysed together, but strong evidence for linkage when families were classified according to mean insulin levels in affecteds (in oral glucose tolerance tests). Specifically, families with the lowest insulin levels showed linkage (P = 2 x 10(-6)) to chromosome 12 near D12S1349. Interestingly, this region contains the gene causing the rare, dominant, early-onset form of diabetes MODY3. Unlike MODY3 families, the Finnish families with low insulin have an age-of-onset typical for NIDDM (mean = 58 years). We infer the existence of a gene NIDDM2 causing NIDDM associated with low insulin secretion, and suggest that NIDDM2 and MODY3 may represent different alleles of the same gene.

Immunoglobulin (Ig) and IgG subclasses in Asian children with bronchial asthma

Selective immunoglobulin deficiencies have been shown to be associated with atopic disease. In this study, serum immunoglobulin (Ig) G, A, M, E and IgG subclasses of 92 Asian asthmatic children were studied and compared with those of age-matched controls. The children, aged between 0.7 and 17.4 years (mean age 7.5 years), were recruited from the National University Hospital, Singapore. The serum Ig levels were measured by enzyme-linked immunosorbent assay, except for IgE which was measured by the fluorescent allergosorbent test. As expected, serum total IgE levels were markedly higher in the asthmatic children than in the controls (geometric mean = 513 units/ml and 164 units/ml, respectively; p < 0.0001). Serum IgM levels were also slightly higher in the asthmatic patients than in the controls (geometric mean = 1.74 and 1.51 milligrams, respectively; p < 0.04). Mean serum IgG and A and IgG subclasses (1-4) levels in the asthmatics did not differ significantly from those in the controls. However, four asthmatic children were found to have selective IgA deficiency (serum IgA < 0.08 milligrams). None of the patients was found to be IgG subclass-deficient.

Sphingomyelin-ceramide turnover in CD28 costimulatory signaling

When the CD28 membrane glycoprotein of T cells binds to its ligand, a signal is transmitted that is required for T cell receptor-induced proliferation and cytokine secretion: T cells are not stimulated by the CD28 signal alone. Ligation of CD28 initiated sphingomyelin hydrolysis and generated ceramide. Treatment of T cells with either exogenous sphingomyelinase or a cell-permeable ceramide analogue. C6-ceramide, mimicked the CD28 signal by inducing T cell proliferation and interleukin-2 gene transcription. Stabilization of interleukin-2 mRNA was also observed in C6-ceramide-treated cells. Thus, the sphingomyelin-ceramide pathway is a candidate for mediating the costimulatory signal.

[Experimental studies on the quality of sophora powder]

In this paper, the contents of total flavonoids, essential oil, tannin, trace elements along with bacteriostatic action in Sophora Powder have been measured. These studies present a scientific evaluation on the quality of Sophora Powder.

Short report: prednisolone withdrawal followed by lymphoblastoid interferon in the therapy of adult patients with presumed childhood-acquired chronic hepatitis B virus infection

Eighteen patients with presumed childhood acquisition of chronic hepatitis B virus infection were initially entered into this randomized controlled trial. Twelve were treated with prednisolone for 4 weeks followed, after a 2-week gap, by thrice weekly lymphoblastoid alpha-interferon for 12 weeks. Two of these had previously acted as untreated controls. Three of the 12 patients (25%) [who were initially hepatitis B virus (HBV) surface antigen (HBsAg), 'e' antigen (HBeAg) and HBV-DNA positive] became HBeAg and HBV-DNA negative during therapy and remained so after 12 months post-therapy follow-up. One of these also lost HBsAg. A further two patients lost HBeAg and HBV-DNA during therapy but relapsed 6 and 9 months later. Two additional patients were HBV-DNA negative but HBeAg positive at the end of follow-up. None of the eight untreated control patients seroconverted during an identical follow-up period. Two further patients were HBsAg and HBeAg positive but HBV-DNA negative at the start of therapy. These were omitted from the final analysis: both subsequently lost HBeAg. The treatment response was associated with a rise in aspartate aminotransferase, peaking 2-6 weeks after prednisolone withdrawal, loss of HBV-DNA 0-8 weeks later and subsequent normalization of liver function tests. Treatment was well tolerated.

Purification and characterization of recombinant-expressed cytochrome P450 2C3 from Escherichia coli: 2C3 encodes the 6 beta-hydroxylase deficient form of P450 3b

Rabbit cytochrome P450 2C3 was expressed from its cDNA in Escherichia coli as a chimeric enzyme in which a portion of the N-terminal membrane anchor sequence of 2C3 was replaced with a modified sequence derived from P450 17 alpha. The nucleotide sequence encoding the N-terminus of P450 17 alpha was modified previously to achieve a high level of expression of P450 17 alpha in E. coli by altering the first eight codons of P450 17 alpha to reflect second codon preferences for high expression and to minimize the potential for the formation of a stable secondary structure of the corresponding RNA transcript. The modified P450 2C3 was expressed at > 400 nmol/liter of culture. P450 2C3 was isolated to apparent electrophoretic homogeneity and a specific content > 14 nmol P450/mg protein. When reconstituted with P450 reductase and dilauroyl-L-alpha-lecithin, the purified E. coli-expressed P450 2C3 catalyzed 16 alpha, but not 6 beta-hydroxylation of progesterone. Expression of unmodified 2C3 from its cDNA in COS-1 cells confirmed the absence of detectable 6 beta-hydroxylase activity. In addition, the enzyme expressed in E. coli is activated by the allosteric effector 5 beta-pregnane-3 beta,20 alpha-diol, with a resultant Vmax = 10 min-1 and Km = 20 microM and is not inhibited by 16 alpha-methylprogesterone. These results indicate that the 2C3 cDNA encodes an enzymatic form characteristic of IIIvo/J and B/J inbred rabbits rather than a second enzymatic form expressed in most outbred and some inbred strains that catalyzes both high efficiency 16 alpha- and 6 beta-hydroxylation of progesterone. Our results have identified the enzyme variant encoded by the 2C3 cDNA and have demonstrated the utility of E. coli for the expression of recombinant P450 enzymes.

Progressive spastic myelopathy in a patient co-infected with HIV-1 and HTLV-II: autoantibodies to the human homologue of rig in blood and cerebrospinal fluid

OBJECTIVE

Human T-cell leukemia virus types I (HTLV-I) and II (HTLV-II) are closely related human retroviruses. HTLV-I has been implicated in a chronic progressive myelopathy, known as tropical spastic paraparesis (TSP) or HTLV-I-associated myelopathy (HAM). We sought to determine whether autoantibodies to brain antigens were present in the cerebrospinal fluid (CSF) of a patient with chronic progressive spastic myelopathy with evidence of both HIV-1 infection and HTLV-I/II seropositivity.

DESIGN

A 54-year-old bisexual man with clinical features of HAM/TSP of over 20 years' duration was followed.

METHODS

We applied discriminatory DNA amplification (polymerase chain reaction) to distinguish HTLV-I from HTLV-II and to verify co-infection with HIV-1. The patient's CSF was used to screen a human brain cDNA expression library to identify antibodies directed against brain antigens. Autoreactive bacteriophage clones were isolated and sequenced.

RESULTS

The patient was found to be co-infected with both HIV-1 and HTLV-II, but not with HTLV-I. HTLV-II proviral levels in the peripheral blood remained relatively constant, despite therapy with zidovudine. Prominent oligoclonal banding of immunoglobulins was present in the patient's CSF. A single repeatedly reactive cDNA clone was identified, by screening with CSF antibody, sequenced, and found to be the human homologue of the rat insulinoma gene, rig.

CONCLUSIONS

HTLV-II infection may predispose to development of a HAM/TSP-like illness. Autoimmune mechanisms, such as autoantibody formation, may play a role in pathogenesis.

[Convergence insufficiency and asthenopia]

22 cases with convergence insufficiency (CI) were presented here. It is found that there was an important relationship between CI and asthenopia. The causes clinical findings, diagnostic criteria, treatment of CI and relation with asthenopia were discussed.

The rheumatoid factor reactivity of a human IgG monoclonal autoantibody is encoded by a variant V kappa II L chain gene

To determine the genetic and molecular basis for rheumatoid factor (RF) autoantibody reactivity in patients with destructive, erosive arthritis, we established a human lymphoblastoid cell line (hRF-1) from a patient with polyarthritis that produced an IgG RF mAb, mAb hRF-1. Studies of isolated H and L chains showed that the specificity of RF reactivity is conferred by mAb hRF-1 L chains. The L chain gene was cloned from a cDNA library prepared from hRF-1 cells. The nucleotide sequence was similar to known V kappa II L chains except for a two nucleotide change corresponding to a change of two amino acids in an invariable region of FR3. A germ-line gene with one of the nucleotide changes was identified by polymerase chain reaction in multiple cell lines, including K562 that does not rearrange Ig genes, but the other nucleotide change appeared to be due to mutation. Either or both of these amino acid changes may contribute to the RF reactivity, because an antibody with the same V kappa II L chain except for these two amino acid changes in FR3 did not have RF reactivity. The RF reactivity of isolated L chains from mAb hRF-1 was confirmed by transfecting COS cells with an expression vector encoding the hRF-1 kappa-chain and showing that the secreted k-chains had RF reactivity. Expression of this variant V kappa II L chain gene may form the basis for RF autoantibody reactivity in some patients.

The rheumatoid factor reactivity of a human IgG monoclonal autoantibody is encoded by a variant V kappa II L chain gene

To determine the genetic and molecular basis for rheumatoid factor (RF) autoantibody reactivity in patients with destructive, erosive arthritis, we established a human lymphoblastoid cell line (hRF-1) from a patient with polyarthritis that produced an IgG RF mAb, mAb hRF-1. Studies of isolated H and L chains showed that the specificity of RF reactivity is conferred by mAb hRF-1 L chains. The L chain gene was cloned from a cDNA library prepared from hRF-1 cells. The nucleotide sequence was similar to known V kappa II L chains except for a two nucleotide change corresponding to a change of two amino acids in an invariable region of FR3. A germ-line gene with one of the nucleotide changes was identified by polymerase chain reaction in multiple cell lines, including K562 that does not rearrange Ig genes, but the other nucleotide change appeared to be due to mutation. Either or both of these amino acid changes may contribute to the RF reactivity, because an antibody with the same V kappa II L chain except for these two amino acid changes in FR3 did not have RF reactivity. The RF reactivity of isolated L chains from mAb hRF-1 was confirmed by transfecting COS cells with an expression vector encoding the hRF-1 kappa-chain and showing that the secreted k-chains had RF reactivity. Expression of this variant V kappa II L chain gene may form the basis for RF autoantibody reactivity in some patients.

Rheumatoid factors specific for active rheumatoid arthritis

To measure rheumatoid factors specific for patients with rheumatoid arthritis an enzyme linked immunosorbent assay (ELISA) was developed to measure rheumatoid factors in human serum that bind a cross-reactive determinant shared on human and other mammalian IgG. Rheumatoid factors that cross link human IgG and sheep IgG in a double binding ELISA were almost completely specific (greater than 99%) for rheumatoid arthritis in assays of 108 sera from patients with rheumatoid arthritis compared with 231 sera from patients with other connective tissue diseases and 365 sera from healthy subjects and patients without these diseases. Moreover, positive tests occurred primarily in patients with active arthritis (r = 0.68). In contrast, these rheumatoid factor autoantibodies were not detected in sera from most of the patients with other autoimmune diseases, including patients with systemic lupus erythematosus. These results show that rheumatoid factors identified in human sera by the double binding test are specific for active rheumatoid arthritis.

Structure of the rabbit cytochrome P450IIC3 gene, a constitutive member of the P450IIC subfamily

Fragments of rabbit DNA have been cloned which encompass the gene for rabbit cytochrome P450IIC3. Cytochrome P450IIC3 is a constitutive member of the cytochrome P450IIC subfamily which contains both constitutive and phenobarbital-responsive genes. The cytochrome P450IIC3 gene spans at least 25 kbp and contains 8 introns which have 5'GT's and 3'AG's and are located in the same positions as in other family II genes. The 5' flanking region contains a consensus TATA site about 25 bp from the RNA initiation site which was mapped by the primer extension method. Other potential regulatory sequences include a CCAAT sequence and sequences similar to binding sites for the liver-specific factor HNF-1 and the general transcription factors AP-1 and OCT. The gene sequence differs from the cytochrome P450IIC3 cloned cDNA sequence in only 2 of 1400 nucleotides, 1 of which results in an amino acid change. Since sequences coding for exon 1 and part of exon 2 were not present in the cloned cytochrome P450IIC3 cDNA, a 475-nucleotide fragment of the 5' end of the cDNA was amplified by the polymerase chain reaction, cloned, and sequenced. The sequence of this cDNA was identical with the gene exon sequence. The protein sequence derived from the gene differs in nine positions from that determined directly for the protein. A comparison of the amino acid sequence by exons with other cytochrome P450IIC proteins revealed that, in general, the similarity was greater in C-terminal exons than in N-terminal ones.(ABSTRACT TRUNCATED AT 250 WORDS)

A conserved anti-DNA antibody idiotype associated with nephritis in murine and human systemic lupus erythematosus

In order to identify unique structural features of pathogenic autoantibodies to DNA in SLE, a murine anti-anti-DNA (anti-Id) mAb (mAb 1C7) was produced in response to immunization of lupus mice with a syngeneic anti-DNA mAb (mAb 3E10). Immunization of lupus mice with mAb 3E10 inhibited production of native anti-DNA antibodies, suppressed development of lupus kidney disease (nephritis), and induced production of anti-anti-DNA (anti-Id) antibodies. mAb 1C7 bound F(ab')2 fragments of mAb 3E10, and it bound other murine anti-DNA mAb, but not murine mAb or polyclonal serum antibodies unreactive with DNA. Moreover, binding of mAb 1C7 anti-Id to mAb 3E10 was inhibited by DNA, suggesting anti-Id binding within or near the binding site for DNA. Furthermore, mAb 1C7 bound serum IgG immunoglobulins from 9/12 patients with lupus nephritis and serum anti-DNA antibodies compared to only 3/12 SLE patients with comparable serum levels of anti-DNA antibodies, but without nephritis (p = 0.04), and only 1/53 SLE patients without serum anti-DNA antibodies, 0/49 patients with rheumatoid arthritis, and 1/47 healthy subjects (p less than 0.001). These results provide evidence that mAb 1C7 identifies a conserved Id associated with anti-DNA antibodies in murine and human SLE and may be useful as a structural probe to characterize pathogenic anti-DNA antibodies in SLE.

A conserved anti-DNA antibody idiotype associated with nephritis in murine and human systemic lupus erythematosus

In order to identify unique structural features of pathogenic autoantibodies to DNA in SLE, a murine anti-anti-DNA (anti-Id) mAb (mAb 1C7) was produced in response to immunization of lupus mice with a syngeneic anti-DNA mAb (mAb 3E10). Immunization of lupus mice with mAb 3E10 inhibited production of native anti-DNA antibodies, suppressed development of lupus kidney disease (nephritis), and induced production of anti-anti-DNA (anti-Id) antibodies. mAb 1C7 bound F(ab')2 fragments of mAb 3E10, and it bound other murine anti-DNA mAb, but not murine mAb or polyclonal serum antibodies unreactive with DNA. Moreover, binding of mAb 1C7 anti-Id to mAb 3E10 was inhibited by DNA, suggesting anti-Id binding within or near the binding site for DNA. Furthermore, mAb 1C7 bound serum IgG immunoglobulins from 9/12 patients with lupus nephritis and serum anti-DNA antibodies compared to only 3/12 SLE patients with comparable serum levels of anti-DNA antibodies, but without nephritis (p = 0.04), and only 1/53 SLE patients without serum anti-DNA antibodies, 0/49 patients with rheumatoid arthritis, and 1/47 healthy subjects (p less than 0.001). These results provide evidence that mAb 1C7 identifies a conserved Id associated with anti-DNA antibodies in murine and human SLE and may be useful as a structural probe to characterize pathogenic anti-DNA antibodies in SLE.

Structure of 5' regions and expression of phenobarbital-inducible rabbit cytochrome P450IIC genes

To analyze phenobarbital-inducible genes in the P450IIC subfamily, fragments of rabbit genomic DNA containing portions of the P450IIC1 and P450IIC4 genes were isolated and the DNA sequences of the 5'-flanking regions and exons were determined and compared to that of the P450IIC2 gene. The sequences have consensus TATA motifs about 20 bp from the mRNA initiation sites as determined by single-strand nuclease mapping and primer extension. Sequences similar to those for proposed liver-specific regulatory factors, HNF-1 and CCAAT, are found in the P450 5'-flanking regions. A glucocorticoid response element is present in the P450IIC2 gene but is not conserved in P450IIC1 or P450IIC4. Other sequences similar to binding sites for AP-1, the octamer binding proteins, and SPH-1 are present. Except for the TATA motif, none of the potential regulatory sequences was conserved at the same location in the different genes. The P450IIC1 and P450IIC2 genes exhibited high similarity detectable by dot matrix analysis throughout the 700 bp of sequenced 5'-flanking region while the P450IIC4 gene exhibited high similarity to both P450IIC1 and P450IIC2 only for about -150 nucleotides from the RNA initiation site. Southern analysis using probes from the 5' region of the P450IIC4 gene suggests that there are at least three closely related members in the P450IIC4 subgroup in agreement with previous studies. After phenobarbital treatment, levels of P450IIC4 mRNA increased about fourfold, as measured by dot blot hybridization with a P450IIC4-specific oligonucleotide probe or by single-strand nuclease mapping of the 5' end of the mRNA, indicating that the P450IIC4 gene characterized in this study is responsive to phenobarbital. Phenobarbital treatment of rabbits increased in vitro transcription of RNA for both the P450IIC1/2 and P450IIC4 gene subgroups but only slightly and transiently for the constitutive P450IIC3 gene.

Randomised controlled trial of lymphoblastoid interferon alfa in Europid men with chronic hepatitis B virus infection

OBJECTIVE

To confirm the findings of pilot studies that interferon alfa is an effective treatment of Europid men with chronic hepatitis B virus infection.

DESIGN

Randomised controlled trial of three months treatment with interferon alfa followed by 12 months of observation.

SETTING

Outpatient clinic of a tertiary referral centre.

PATIENTS

37 Treated men (six anti-HIV positive) and 34 untreated men (nine anti-HIV positive) who met the criteria for the trial. Four controls failed to complete follow up.

INTERVENTIONS

The treated group received subcutaneous injections of 5-10 MU interferon alfa/m2 daily for five days, then 10 MU/m2 thrice weekly for 11 weeks. Follow up continued at monthly intervals for 12 months. Untreated controls were monitored over the same period.

MAIN OUTCOME MEASURE

Hepatitis B e antigen and hepatitis B virus DNA state after 15 months of observation.

RESULTS

12 Of the 37 treated patients cleared hepatitis B e antigen and hepatitis B virus DNA, whereas only one of 30 untreated controls seroconverted over the same period--an increased response rate of 29% (95% confidence interval 13% to 45%). The life table estimate of response at 15 months was 35% in treated patients, an increase of 32% above controls (95% confidence interval 16% to 48%). The response rates in groups by predictive pretreatment variables were 12 of 31 anti-HIV negative patients (excess response 34%; 95% confidence interval 14% to 54%), 12 of 26 with chronic active hepatitis before treatment (excess response 46%; 27% to 65%), and 12 of 21 with a pretreatment serum aspartate aminotransferase activity greater than 70 IU/l (excess response 46%; 16% to 76%). The combination of these factors predicted response with a sensitivity of 100% and a specificity of 80%. Four of the 12 responders, who had all been infected for less than two years, also lost hepatitis B surface antigen. Treatment was well tolerated.

CONCLUSIONS

Interferon alfa is effective in the treatment of a proportion of Europid men with chronic hepatitis B virus infection, who might be identified before treatment. Additional strategies are required to improve the rate of response.

Bilirubin toxicity in a neuroblastoma cell line N-115: I. Effects on Na+K+ ATPase, [3H]-thymidine uptake, L-[35S]-methionine incorporation, and mitochondrial function

Though bilirubin is reported to affect a variety of cellular functions, the primary target of its toxic effect is still not known. A major problem in understanding this is the wide variation in results reported by different groups. This is probably due to the differences in stability of bilirubin solutions arising from large differences in bilirubin:albumin molar ratios used in experiments. Hence in studying the toxic effects of bilirubin in tissue culture systems, it is important to be certain that the bilirubin is maintained in solution throughout the time of the exposure to bilirubin. Spectrophotometric measurements have shown that bilirubin is stable in Dulbecco's modified Eagle medium solution at bilirubin:albumin molar ratios up to 3. Under these defined conditions, bilirubin was found to affect Na+K+ ATPase, [3H]-thymidine uptake, L-[35S]methionine incorporation into protein and mitochondrial function at bilirubin concentrations up to 125 microM and bilirubin:albumin molar ratio of 1.5. Toxic effects on all parameters measured were evident at bilirubin:albumin molar ratio of 1.5 after a minimum of 2 h of exposure. No effect was evident at a bilirubin:albumin molar ratio below 1. Although it is not possible to identify with certainty the primary target, the effect on mitochondrial function appeared earlier and was more profound than that seen with the other assessed functions.

Isolation and structure determination of Pachybasium cerebrosides which potentiate the antifungal activity of aculeacin

A set of four cerebrosides was isolated from a Pachybasium species and purified by preparative reversed-phase HPLC. All four products displayed activity in a natural product screen aimed at detecting novel cell wall-active antifungal agents based on synergy with the known glucan synthetase inhibitor, aculeacin. Based on degradation studies, fast atom bombardment mass spectrometry and 13C and high field 1H NMR techniques, the structure of the major cerebroside was determined to be (4E,8E)-N-D-2'-hydroxy-(E)-3'- hexadecenoyl-1-O-beta-D-glucopyranosyl-9-methyl-4,8-sphingadiene. The other components were found to be the corresponding 2'-hydroxypalmitic acid analog with one less double bond and an analogous pair containing 2'-hydroxystearic acid with and without the 3' double bond.

A study of prescribed H1-antihistamine preparations over a period of 12 months in community pharmacy

A survey on the prescribing pattern of H1-antihistamine preparations was carried out in four socio-economic areas in Liverpool: the City Centre, an Affluent Area, a Poor area and a Council Estate. The purpose of this study was to find out which H1-antihistamines were prescribed from the wide range available; to discover if there was a trend in the use of these agents over a 12-month period and to suggest possible explanations for these findings. The majority of H1-antihistamine preparations were prescribed in the Affluent Area followed by the City Centre, Poor Area and the Council Estate. In all four areas, over 7.0% of all total items dispensed in a year contained H1-antihistamine drugs, and the lowest use (3.7-9.2%) fell in the summer months while the highest use was in January (8.2-14.1% of items containing H1-antihistamine dispensed per month). Thus the general trend in the use of these drugs may not follow the trend of the hay fever season and it is probably true that H1-antihistamines were more frequently prescribed for treatment of other conditions (common cough and cold) than rhinitis alone. The most widely prescribed classes of H1-antihistamines were alkylamines and ethanolamines, followed by the phenothiazines and ethylenediamines while the piperazines were not prescribed. Triprolidine, diphenhydramine, promethazine and brompheniramine were the top four most widely prescribed drugs.

Bilirubin diffusion through lipid membranes

The possibility that bilirubin can diffuse through lipid bilayers is investigated with liposomes prepared from dipalmitoylphosphatidylcholine (DPPC), egg phosphatidylcholine (egg PC) with 22 mole percent cholesterol, and a lipid extract preparation from N115 neuroblastoma cells. Liposomes were prepared with internalized bilirubin and bovine or human serum albumin, and bilirubin efflux into an exogenous solution of human serum albumin was measured. Efflux from DPPC liposomes was significantly higher above the phase transition temperature than below it. This change was dependent on the lipid undergoing a phase transition and could not be accounted for by 6 K change in temperature. Maximum bilirubin efflux from egg PC-cholesterol liposomes was found to depend on the relative internal and external albumin pools, suggesting an equilibrium distribution of bilirubin between them. These observations demonstrate that bilirubin can diffuse freely through these lipid membranes.

Bilirubin toxicity in neural cell lines N115 and NBR10A

The toxicity of bilirubin was investigated in 2 neural cell lines NBR10A and N115 using a quantitative dye assay 3-(4,5 dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium biomide (MTT) as a measure of cell viability and [3H]thymidine incorporation as a measure of DNA synthesis. Short exposures (up to 2 h) to bilirubin, even up to a bilirubin-albumin molar ratio of 1.5, yielded no evidence of toxicity using these assays. At longer exposure times (24 h) a decrease in cell viability and [3H]thymidine incorporation was detected at a molar ratio of 0.8 when the bilirubin concentration was 0.1 mM or higher, whereas lower bilirubin levels at this molar ratio showed no deleterious effect. The effect of bilirubin is more pronounced at a molar ratio of 1.5 with longer incubation periods. The MTT assay showed the N115 cells appeared to be more resistant to bilirubin cytotoxicity than NBR10A cells, a finding which was not obtained from [3H]thymidine incorporation studies. This discrepancy can be explained by the fact that we are measuring two different variables; the MTT assay estimates the number of viable cells at the end of the experiment by measuring mitochondrial function whereas the [3H]thymidine assay measures the rate of DNA synthesis during the last 2 h of the experiment. The concentration effect of bilirubin is evident from the [3H]-thymidine studies in that at a molar ratio of 1.5 and bilirubin concentration of 0.075 mM or higher, there is both cell kill (decrease in DNA) and inhibition of [3H]thymidine incorporation (decrease in specific activity).(ABSTRACT TRUNCATED AT 250 WORDS)

[Nonspecific immunity factors and elimination of circulating immune complexes in patients with myocardial infarct in the 1st phase of rehabilitation]

A considerable increment of humoral immunity parameters was demonstrated during the 3d-5th week after the onset of myocardial infarction (MI). The levels of IgG and IgE were increased, and those of circulating immune complexes (CIC), decreased significantly in patients with their first diagnosed infarction, as compared to those with repeated MI. Patients with repeated MI showed significantly reduced blood C3c, C4 and the phagocyte index in the presence of high blood levels of CIC and C-reactive protein, as compared to patients with primary infarction. The results are indicative of a considerable activation of the complement and the phagocytic system and CIC elimination in patients with their first MI diagnosis, and the absence of such a stimulation in repeated MI cases.

Phototherapy and photopharmacology

The activation of 8-methoxypsoralen (8-MOP) by long-wavelength ultraviolet A light (UVA, 320-400 nm) induces the formation of interstrand cross-links in DNA. Psoralen plus UVA (PUVA) is widely used in the treatment of psoriasis, a hyperproliferative disease of the skin. A new psoralen plus UVA therapy has been developed in which the 8-MOP-containing blood of cutaneous T cell lymphoma (CTCL) patients is irradiated with UVA light extracorporeally (i.e., extracorporeal photopheresis). The first group of patients had the leukemic variant of CTCL. A regimen of two treatments on successive days at monthly intervals produced a clinical response in eight of 11 patients. In this review the properties of several psoralens (both naturally occurring and synthetic derivatives) are compared, using several assays (DNA cross-linking, inhibition of lymphocyte response to mitogen stimulation, and cell viability). The development of a panel of monoclonal antibodies that recognize 8-MOP-modified DNA is also described. These antibodies have been used to quantitate 8-MOP photoadduct levels in human DNA samples. In addition to the psoralens, the light activation of two other compounds, gilvocarcin and an insulin-psoralen conjugate, is described.

Further purification of neutrophil migration inhibition factor from T lymphocytes (NIF-T): evidence that NIF-T and leukocyte inhibitory factor (LIF) are immunologically distinct

Neutrophil migration inhibition factor from T lymphocytes (NIF-T) purified by antibody affinity chromatography and gel filtration chromatography was radioiodinated and identified as a 26,000-MW protein by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). NIF-T was identified by elution of biological activity from gel fractions and selective adsorption of a radioiodinated mediator by HL60 cells differentiated in the presence of dimethyl sulfoxide (DMSO) to develop receptors for NIF-T. A goat neutralizing antibody for NIF-T neutralized and immunoprecipitated migration inhibition activity in the conditioned medium from Mo T-lymphoblast cells and human peripheral blood lymphocytes (PBL) cultured with concanavalin A (Con A), but not from RPMI 1788 B-lymphoblast cells with leukocyte migration inhibitory factor (LIF) activity. These studies distinguish NIF-T both chemically and immunologically from LIF.

Characterization of mouse and human monoclonal antibodies cross-reactive with SLE serum antibodies to guanosine

Two new monoclonal antibodies, one a mouse IgM and the other a human IgM that reacted with guanosine, were compared to human serum antibodies from patients with systemic lupus erythematosus (SLE). The human monoclonal antibody was polyspecific in its binding to the nucleoside bases, whereas the mouse monoclonal antibody was relatively specific for guanosine when compared by using an enzyme-linked immunosorbent assay (ELISA). Neither antibody bound polyguanylic acid or denatured single-stranded (ss) DNA, however. Serum IgG antibodies from seven patients with SLE cross-reacted with the mouse monoclonal antibody and showed considerable specificity for guanosine. In contrast, the human serum IgG antiguanosine antibodies also bound ssDNA but not dsDNA or polyguanylic acid. Serum IgG antibodies to guanosine measured by ELISA from the seven SLE patients had a decreased response when compared to the total serum IgG response to ssDNA, and most of the antibodies that bound guanosine also bound ssDNA. These studies provide new evidence that there are specific IgG antibodies to guanosine in SLE sera that are a small fraction of the antibodies to ssDNA. Further efforts to define the role of these guanosine antibodies in SLE may provide a better understanding of the basic mechanisms responsible for the development of SLE in man.

Characterization of mouse and human monoclonal antibodies cross-reactive with SLE serum antibodies to guanosine

Two new monoclonal antibodies, one a mouse IgM and the other a human IgM that reacted with guanosine, were compared to human serum antibodies from patients with systemic lupus erythematosus (SLE). The human monoclonal antibody was polyspecific in its binding to the nucleoside bases, whereas the mouse monoclonal antibody was relatively specific for guanosine when compared by using an enzyme-linked immunosorbent assay (ELISA). Neither antibody bound polyguanylic acid or denatured single-stranded (ss) DNA, however. Serum IgG antibodies from seven patients with SLE cross-reacted with the mouse monoclonal antibody and showed considerable specificity for guanosine. In contrast, the human serum IgG antiguanosine antibodies also bound ssDNA but not dsDNA or polyguanylic acid. Serum IgG antibodies to guanosine measured by ELISA from the seven SLE patients had a decreased response when compared to the total serum IgG response to ssDNA, and most of the antibodies that bound guanosine also bound ssDNA. These studies provide new evidence that there are specific IgG antibodies to guanosine in SLE sera that are a small fraction of the antibodies to ssDNA. Further efforts to define the role of these guanosine antibodies in SLE may provide a better understanding of the basic mechanisms responsible for the development of SLE in man.

High malformation rates and decreased mortality in infants of diabetic mothers managed after the first trimester of pregnancy (1956-1978)

Over a period of 23 years we accumulated data on 182 pregnant juvenile diabetic subjects during pregnancy, labor, and delivery. Diabetic subjects were evaluated generally after the first trimester of pregnancy. Data examined included diabetic class, maternal complications of pregnancy, and infant morbidity and mortality. Data were analyzed in two periods-before and after 1970. In the second period, maternal polyhydramnios and acidosis rates improved, neonatal problems of homeostasis did not change significantly, and combined fetal and neonatal losses fell from 34.7% to 16.4%. The neonatal malformation rate, however, increased from 1.4% to 16.8% and was not influenced by maternal age or diabetic class.

Clinical relevance of the plasma reserve albumin binding capacity for bilirubin (RABC) and "free" bilirubin concentration

An analysis of 55 plasma samples from 46 jaundiced newborn infants showed that endogenous "free" bilirubin levels bear no significant correlation to reserve albumin binding capacities for bilirubin as determined by both the Sephadex G-25 gel filtration and the enzymatic peroxidation technique (r = 0.14, p less than 0.05). This contrasts with the significant correlation between the "free" bilirubin concentrations and the bilirubin/albumin molar ratios in the same plasma samples (r = 0.75, p less than 0.001). The results of this study suggest that if "free" bilirubin is the "driving force" in the pathogenesis of bilirubin encephalopathy then the use of the reserve albumin binding capacity for bilirubin as the only guide in predicting the risk of kernicterus may not be adequate.

Holoprosencephaly in a Down syndrome child

Gross malformation of the central nervous system (CNS) is rare in Down syndrome (DS). To our knowledge we report for the first time the association of trisomy 21 and holoprosencephaly. Because of the low probability of chance concurrence due to unrelated causes, a causal relationship between these two conditions in the patient must be presumed. The anatomic similarity of the holoprosencephalic defect in this infant to that seen in others with autosomal dominant, recessive, sporadic, or syndromal forms of holoprosencephaly, supports the hypothesis that: a) this CNS defect is a causally nonspecific developmental field complex (DFC); b) the increased incidence of such DFC's in the DS represents the result of a nonspecific decrease of developmental homeostasis [Waddington, 1975] due to autosomal aneuploidy.

Plasma carnitine levels during intravenous feeding of the neonate

The premature infant has a limited capacity for fatty acid oxidation. This study shows that solutions commonly used for intravenous feedings in the newborn infant contain no carnitine. Infants maintained on this solution have significantly lower total, free, and acylcarnitine levels as compared to when they are fed orally with expressed human milk or a proprietary formula, which is known to contain carnitine. The exogenous supply of carnitine to the premature infant may have a significant influence on the ability to stimulate optimal fatty acid oxidation.

Lipid metabolism in the neonate. III. The ketogenic effect of Intralipid infusion in the neonate

The ketogenic potential of Intralipid was studied in two groups of infants: 12 were SGA and 15 AGA; all were clinically stable and less than 48 hours of age. During four-hour Intralipid tolerance tests, the SGA infants achieved significantly higher plasma TG and FFA levels. Both groups of infants significantly increased the concentration of ketone bodies; however, there was no difference in the levels achieved. In view of the slower clearance rate of TG and the higher levels of FFA in SGA infants, it is speculated that in addition to a possible defective lipoprotein lipase system and a decrease in number and size of the adipose cells, beta-oxidation of FFA to ketones may be occurring at a slower rate. The generation of high levels of ketones during Intralipid infusion period in both groups of infants indicates that SGA infants can handle ketone bodies as readily as AGA infants.

Gentamicin and albumin-bilirubin binding. An in vivo study

Ten newborn infants were given gentamicin intramuscularly. Over a postinjection interval of 12 hours, no significant change occurred in the total binding capacity of serum albumin for bilirubin or in concentrations of serum bilirubin levels. There was no correlation between concentrations of serum gentamicin and the total binding capacity or serum bilirubin. This study provides in vivo data that supports recent in vitro experiments showing that gentamicin does not alter bilirubin-albumin binding.

Bilirubin quantitation with lipemic plasma

1. In the presence of lipemia, the estimation of BR by diazo method is variable and hence unreliable. 2. The estimation of BR in lipemic plasma by the use of the A-O bilirubinometer yielded BR levels which were consistently lower than theoretical values. 3. By regression analysis of the percent error in BR estimation, (using the A-O bilirubinometer) and TG Concentrations, a straight line is obtained. Based upon this line, a correction factor for plasma BR concentration in the range of 5-25 mg/dl can be obtained if the degree of lipemia is known.

Variance in albumin loading in exchange transfusions

To assess the rationale of albumin priming prior to exchange transfusions, 42 hyperbilirubinemic infants who required exchange transfusions were randomly assigned to one of two groups. Group I consisted of 15 infants who were given intravenously 1 gm/kg of salt-poor human serum albumin one hour before the exchanges. Group II, which consisted of 27 infants, received simple exchanges. No statistical differences were found in variations in reserve albumin-binding capacity, bilirubin, albumin, or red cell bilirubin at pre and one-hour post albumin infusion in the primed infants. The amount of bilirubin removed per kilogram is directly correlated to plasma bilirubin concentration (r=0.87). No significant difference in efficiency on bilirubin removal was seen between the two groups. Beneficial effects of albumin therapy was apparent only in those infants with low RABC as determined by the sephadex gel filtration technique.

Lipid metabolism in the neonate. II. The effect of Intralipid on bilirubin binding in vitro and in vivo

The relationship between Intralipid fat emulsion and the binding of bilirubin to protein and cells was studied in vitro and in vivo. In the in vitro system, Intralipid had no beneficial effect in augmenting billirubin binding in adult whole blood. The unmetabolized Intralipid had no adverse effect on bilirubin binding in vitro. Twenty-seven neonates were infused with Intralipid (1 gm/kg) over a 4-hour period; the SGA infants achieved very high plasma concentrations of free fatty acids. When the molar ratio of free fatty acids to albumin in plasma was greater than six, the free fatty acids displaced bilirubin from albumin, resulting in the generation of free bilirubin. It is suggested that the molar ratios of free fatty acids to albumin in plasma be followed in any infant who is receiving Intralipid and that the dose of Intralipid be adjusted to maintain this ratio below six.

Lipid metabolism in the neonate. I. The effects of Intralipid infusion on plasma triglyceride and free fatty acid concentrations in the neonate

To determine the ability of the neonate to metabolize Intralipid, it was infused in a dose of 1 gm/kg of body weight over a 4-hour period to 27 infants in the first 48 hours of life. Differences in the metabolism of this lipid were related to gestational age and to weight for gestational age. Premature AGA infants of less than 33 week's gestation hydrolyzed the triglyceride to FFA more slowly than did AGA infants whose gestation was greater than 33 weeks. The SGA infants achieved very high plasma levels of triglycerides and free fatty acids during the infusion and cleared the lipid very slowly in the postinfusion period. This suggested impaired hydrolysis of the triglyceride and deficient uptake and/or utilization at a cellular level of the resulting free fatty acids in SGA infants.

Retinal and post-retinal components of visual illusions

A technique is presented permitting control of input to each hemiretina and each hemisphere, of the various elements of a visual illusion. When the retinal effects and post-retinal effects are added, the result is greater than the total illusory effect. This is believed due to the mixing between hemispheres via the corpus callosum, and suggests a possible means of assessing the role of the corpus callosum.