Affinity modulation of platelet integrin alphaIIbbeta3 by beta3-endonexin, a selective binding partner of the beta3 integrin cytoplasmic tail

Platelet agonists increase the affinity state of integrin alphaIIbbeta3, a prerequisite for fibrinogen binding and platelet aggregation. This process may be triggered by a regulatory molecule(s) that binds to the integrin cytoplasmic tails, causing a structural change in the receptor. beta3-Endonexin is a novel 111-amino acid protein that binds selectively to the beta3 tail. Since beta3-endonexin is present in platelets, we asked whether it can affect alphaIIbbeta3 function. When beta3-endonexin was fused to green fluorescent protein (GFP) and transfected into CHO cells, it was found in both the cytoplasm and the nucleus and could be detected on Western blots of cell lysates. PAC1, a fibrinogen-mimetic mAb, was used to monitor alphaIIbbeta3 affinity state in transfected cells by flow cytometry. Cells transfected with GFP and alphaIIbbeta3 bound little or no PAC1. However, those transfected with GFP/beta3-endonexin and alphaIIbbeta3 bound PAC1 specifically in an energy-dependent fashion, and they underwent fibrinogen-dependent aggregation. GFP/beta3-endonexin did not affect levels of surface expression of alphaIIbbeta3 nor did it modulate the affinity of an alphaIIbbeta3 mutant that is defective in binding to beta3-endonexin. Affinity modulation of alphaIIbbeta3 by GFP/beta3-endonexin was inhibited by coexpression of either a monomeric beta3 cytoplasmic tail chimera or an activated form of H-Ras. These results demonstrate that beta3-endonexin can modulate the affinity state of alphaIIbbeta3 in a manner that is structurally specific and subject to metabolic regulation. By analogy, the adhesive function of platelets may be regulated by such protein-protein interactions at the level of the cytoplasmic tails of alphaIIbbeta3.

p53 and K-ras status in duodenal adenomas in familial adenomatous polyposis

BACKGROUND

The genetic alterations in patients with familial adenomatous polyposis (FAP) and duodenal adenomas are poorly characterized when compared with data relating to colorectal tumorigenesis in the same patients.

METHODS

Point mutation of the K-ras oncogene and point mutation and overexpression of the TP53 tumour suppressor gene were investigated in 32 duodenal polyps (seven without mucosal pathology, 23 with mildly dysplastic adenomas and two with moderately dysplastic adenomas) from 21 patients with FAP.

RESULTS

K-ras mutation, TP53 mutation or positive p53 staining were not found in duodenal polyps without histological abnormality. Of 25 duodenal adenomas, K-ras mutation was found in three (two mildly dysplastic, one moderately dysplastic), 20 showed positive p53 immunostaining, and mutation of the TP53 gene was found in one moderately dysplastic adenoma. p53 protein overexpression in duodenal adenomas was significantly more frequent than mutation of either K-ras or TP53 (P < 0.01).

CONCLUSION

p53 dysfunction is a hallmark of duodenal adenomas in patients with FAP. Overexpression may indicate DNA damage and thus an early step in tumorigenesis.

Molecular cloning of anti-SS-A/Ro 60-kDa peptide Fab fragments from infiltrating salivary gland lymphocytes of a patient with Sjögren's syndrome

Anti-SS-A/Ro antibodies are commonly found in systemic autoimmune diseases such as Sjögren's syndrome and systemic lupus erythematosus, and some of these antibodies appear to be responsible for certain pathological lesions including congenital heart block in neonatal lupus. In this study, we generated three human antibody Fab fragments that specifically bind to SS-A/Ro 60-kd peptide from salivary gland lymphocytes of a patient with Sjögren's syndrome by using a phage-display technique. Sequence analysis demonstrated that two of the three Fab clones (E-42 and E-60) used homologous heavy chains derived from the germline VH gene DP73 in combination with different light chains which were derived from germline V kappa gene L6 and V lambda gene DPL23. The third Fab clone (E-56) used another heavy chain derived from the germline VH gene DP31 in combination with the identical light chain as that of E-42. All three Fab clones revealed a high number of somatic mutations that likely occurred in the context of antigen selection. These findings suggest the restricted usage of VH and VL genes of anti-SS-A/Ro antibodies in salivary gland lymphocytes of the patient.

Magnesium lithospermate B suppresses the increase of active oxygen in rats after subtotal nephrectomy

Subtotally nephrectomized rats were found to have decreased activities of superoxide dismutase (SOD) and catalase, and spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) showed that the amount of hydroxyl radical in the residual kidney tissue was greater than that in normal rat kidney. This indicated both direct and indirect involvement of free radicals in renal failure. In contrast, rats given magnesium lithospermate B (10 mg/kg body weight) orally for 30 days after subtotal nephrectomy showed restoration of SOD and catalase activities to almost normal levels. Hydroxyl radical, which is highly reactive and for which there is no scavenger system in the body, was decreased markedly in kidney homogenates obtained from rats given magnesium lithospermate B and in an experimental system for hydroxyl radical production to which magnesium lithospermate B was directly added. The increased levels of uremic toxins in the blood were also low in rats given magnesium lithospermate B. This indicates that magnesium lithospermate B helps to inhibit the progression of renal failure by scavenging radicals.

[Enteral alimentation at home: why PEG now?]

The history of percutaneous endoscopic gastrostomy (PEG) is relatively short. In 1980, a report entitled "Gastrostomy without laparotomy: A percutaneous endoscopic technique" by Ponsky and Gaudere was first published in the Journal of Pediatric Surgery. Thereafter, PEG soon saw widespread use in Western countries because of its clinical efficacy and economy. It has been performed in about 170,000 cases annually in the US. In contrast, its spread in Japan has been extremely slow: only about 10,000 cases have undergone this procedure annually, and this number accounted for less than 5% of patients receiving enteral alimentation. The reason why PEG has not spread may be the medical insurance system in Japan and the local distaste for operation scarring. However, in consideration of the unprecedented ageing of society that is surely coming in the near future, the role of PEG in Japan must be reexamined. In this report, we presented the methodology of enteral alimentation at home by means of PEG, giving special consideration to: (1) "What points are improved by using enteral alimentation at home by means of PEG in various diseases; (2) dysphagia due to cerebral angiopathy; (3) terminal cancer; (4) otolaryngological diseases; and (5) Crohn disease. We also discussed "Why PEG is important now?" in performing enteral alimentation at home.

Influence of cisapride on the pharmacokinetics and antihypertensive effect of sustained-release nifedipine

To investigate the clinical significance of interactions between cisapride and sustained-release nifedipine, we compared the plasma nifedipine concentration and blood pressure after administration of nifedipine alone (20 mg) with those obtained after administration of nifedipine cisapride (2.5 mg) in 20 patients with hypertension. The plasma nifedipine level was not altered by cisapride at one hour after administration, but was significantly increased at two (p < 0.01), three (p < 0.01), and four (p < 0.05) hours when compared with the level measured after nifedipine alone. Cisapride significantly decreased the mean blood pressure at three hours (p < 0.05) after administration of nifedipine. The acetaminophen method was used to determine gastric emptying time. The plasma concentration of acetaminophen at 45 minutes after administration was significantly increased by cisapride, suggesting that enhanced gastrointestinal motility might be the basis for the increase in the plasma nifedipine concentration. These results suggest that enhancement of the antihypertensive effect of nifedipine can occur when the drug is prescribed with cisapride, and that caution is needed when using such a combination therapy.

Laparoscopic-assisted colectomy with lymph node dissection for invasive carcinoma of the colon

The results of performing laparoscopic-assisted colectomy in 20 patients with invasive carcinoma of the colon were analyzed in this study. The site of the lesion was the right colon in 5 patients, the transverse colon in 1, the left colon in 13, and the rectosigmoid in 1. In 2 patients, the laparoscopic procedure needed to be converted to an open laparotomy. Limited lymph node dissection (R1+, R2) was carried out in 10 patients and extensive node dissection (R3) was carried out in 9 patients. The histological depth of invasion in the 18 patients who underwent laparoscopic-assisted colectomy was the submucosa in 9, the muscularis propria in 2, and the extramuscular layer in 7. There were 3 patients who developed postoperative complications, 1 of whom underwent reoperation due to perforation of the colon. The postoperative course of the patients who underwent laparoscopic surgery was compared with that of a retrospectively selected control group of patients who had undergone open laparotomy. The postoperative recovery of the patients who underwent laparoscopic surgery was significantly faster than that of those who had undergone open laparotomy. Thus, we consider that laparoscopic-assisted colectomy with lymph node dissection is technically feasible provided that patients are properly selected. This procedure may be indicated not only for colonic carcinoma in the early stage, but also for that with invasion of the muscularis propria or the extramuscular layer.

[Home oxygen therapy (HOT) in patients with pulmonary tuberculosis sequelae--comparison between patients medically treated and those surgically treated]

In Japan there are about 40,000 patients under home oxygen therapy (HOT), of whom about 30 to 40% are pulmonary tuberculosis sequelae (TBS). These patients can be divided into three groups depending on the treatments they had, Group 1: those who had medical treatments only, Group 2: those who had artificial pneumothorax, and Group 3: those who had thoracoplasties or other surgical treatments. The purpose of this study was to observe the distributions and possible differences in the survival rates among these groups. The study included 1537 patients with TBS under HOT followed at National Hospitals and Sanatoriums nationwide in Japan. In 819 patients the treatments were specified and of those 354 were in Group 1, 29 in Group 2, and 436 in Group 3, so that the proportion of surgically treated patients in PTS was estimated between 28.4% (436/ 1537) to 53.2% (436/819). The ages at the onset of tuberculosis, at the start of HOT and the intervals in between were 36.6, 66.2 and 29.8 in Group 1, and 26.8, 65.5, and 38.1 in Group 3 respectively. Though the ages at the start of HOT were the same, those at the onset of tuberculosis were about ten years younger in Group 3 than in Group 1. Comparing Group 1 and 3, the survival rates after the initiation of HOT (Kaplan-Meier method) was better in Group 2 (surgically treated) than in Group 1 (medically treated). It is speculated that the reason could be a better preservation of the function of the remaining lung in the surgically treated and a higher incidence of obstructive impairments in the medically treated patients.

Affinity modulation of the platelet integrin alpha IIb beta 3 by alpha-chymotrypsin: a possible role for Na+/Ca2+ exchanger

In the present study, we have investigated the mechanism of affinity modulation of alpha IIb beta 3 by chymotrypsin. We first confirmed that alpha-chymotrypsin could activate alpha IIb beta 3 (approximately 7,000 molecules per platelet) without major intracellular signaling. However, we unexpectedly found that high concentrations of amiloride dose-dependently inhibited 125I-fibrinogen binding to the chymotrypsin-treated platelets, as well as the platelet aggregation (IC50 [50% inhibitory concentration] for fibrinogen binding, 530 mumol/L). In contrast, amiloride did not inhibit alpha IIb beta 3 activation induced by anti-alpha IIb beta 3 monoclonal antibody PT25-2 or AP5. To identify the pathway involved, the effects of alteration of Na+ gradient in platelets were examined. Lowering Na+ gradient by replacing extracellular Na+ with tetramethylammonium (TMA) increased the number of activated alpha IIb beta 3 by twofold, as assessed by fibrinogen-binding assay. The incubation of platelets with ouabain, a Na+/K(+)-adenosine triphosphatase (ATPase) inhibitor, further augmented alpha IIb beta 3 activation. These data suggested that a likely candidate for the pathway was Na+/Ca2+ exchanger. At 140 mmol/L [Na+]o, 45Ca2+ influx to the chymotrypsin-treated platelets was twofold greater than that to non-treated platelets. Replacement of Na+ with TMA further increased the Ca2+ influx, and the increase was inhibited by amiloride dose-dependently. 3',4'-Dichlorobenzamil (DCB) and bepridil, relatively specific inhibitors of Na+/Ca2+ exchanger, also inhibited the chymotrypsin-induced alpha IIb beta 3 activation, and the IC50 values of these inhibitors for fibrinogen binding were 25 mumol/L and 52 mumol/L, respectively. Moreover, platelet aggregation induced by various physiologic agonists was inhibited by DCB or bepridil, while platelet agglutination by ristocetin was not. Our data newly suggest that Na+/Ca2+ exchanger operating in reverse mode may be directly involved in inside-out signaling that activates alpha IIb beta 3.

A single nucleotide insertion in codon 317 of the CD36 gene leads to CD36 deficiency

CD36 is a multifunctional integral-membrane glycoprotein that acts as a receptor for thrombospondin, collagen, long-chain fatty acids, and oxidized LDL. Platelet CD36 deficiency can be divided into two groups. In type I, neither platelets nor monocytes/macrophages express CD36; in type II, monocytes/macrophages express CD36 but platelets do not. Two known mutations cause CD36 deficiency, ie, a 478C-->T substitution in codon 90 (proline90-->serine) and a dinucleotide deletion at nucleotide 539 in codon 110. In this study we investigated a type I Japanese subject (A.T.) and identified a new mutation, a single nucleotide insertion at nucleotide 1159 in codon 317. This mutation leads to a frameshift and the appearance of a premature stop codon. CD36 gene analysis indicated that A.T. was a compound heterozygote for a dinucleotide deletion at nucleotide 539 and the single nucleotide insertion at nucleotide 1159. RNase protection studies suggested that the new mutation as well as the dinucleotide deletion led to a marked reduction in the level of CD36 mRNA in her macrophages. However, the new mutation could be detected in macrophage but not platelet CD36 mRNA. These data suggest that the allele having the single nucleotide insertion in this subject has an additional abnormality that results in the absence of the mutated CD36 mRNA in platelets.

Predicting infection in hospitalized patients with systemic lupus erythematosus

To identify the risk factors for infection and to develop a model for the prediction of infection in hospitalized patients with active systemic lupus erythematosus (SLE), we carried out a retrospective cohort study with clinical data collected from 121 consecutive patients with active SLE. Seventeen patients had infection within 6 months of beginning steroid therapy for active SLE. Independent multivariate predictors of infection were a decrease in the serum albumin value, an increase in the serum creatinine value, and prednisolone use in a dose of > or = 60 mg/day without methylprednisolone pulse therapy. The error rate of the model by 10-fold cross-validation method was 12%, sensitivity was 65%, specificity was 91%, and positive predictive value was 55%. Four nonsurvivors were correctly discriminated. Use of this model could contribute to earlier diagnosis of infection and may assist decisions regarding empiric antimicrobial administration in patients with SLE.

[A dual occurrence of endometrial and gastric adenocarcinomas in systemic lupus erythematosus]

The association of systemic lupus erythematosus (SLE) and solid tumors is infrequent. Furthermore, there has been no previous description of multiple occurrence of carcinoma in a single patient with SLE. We describe clinical picture of the patient who had dual occurrence of endometrial and gastric adenocarcinomas in addition to clinically active SLE and organ system involvement.

Overexpression of p53 in duodenal tumours in patients with familial adenomatous polyposis

Duodenal polyps and tumours of different histology from patients with familial adenomatous polyposis (FAP) were examined for p53 overexpression to determine the genetic events in duodenal tumorigenesis. Samples from endoscopic biopsy specimens of 152 duodenal adenomatous polyps (taken from 79 patients) and from 13 surgically resected adenomatous polyps or cancers (taken from nine patients) were studied by routine histological examination and immunohistochemistry. p53 was overexpressed in: 0 per cent of normal mucosa samples (none of 29), 25 per cent of tubular adenomas (28 of 111), 72 per cent of tubulovillous and villous adenomas (13 of 18) and 100 per cent of duodenal cancers (seven of seven); and in 28 per cent of mildly dysplastic polyps (32 of 113), 56 per cent of moderately or severely dysplastic polyps (nine of 16) and 100 per cent of cancers (seven of seven). Overexpression of p53 increased with passage down the adenoma-carcinoma pathway and might therefore be a valuable additional marker of risk for duodenal malignancy in patients with FAP.

Platelet-associated anti-glycoprotein (GP) IIb-IIIa autoantibodies in chronic immune thrombocytopenic purpura mainly recognize cation-dependent conformations: comparison with the epitopes of serum autoantibodies

Platelet-associated and serum anti-glycoprotein (GP) IIb-IIIa autoantibodies were investigated in 57 patients with chronic immune thrombocytopenic purpura (ITP). In modified antigen capture ELISA (MACE) using GPIIb-IIIa-specific-, GPIIb-specific-, and GPIIIa-specific-monoclonal antibody (mAb) for antigen capture, platelet-associated anti-GPIIb-IIIa antibodies were detected in 14 out of 37 patients (38%), and these antibodies could be detected with all 3 mAbs used for antigen capture. In the MACE using EDTA-treated platelets at 37 degrees C, the reactivity of platelet-associated anti-GPIIb-IIIa antibodies in 9 out of 10 patients was markedly reduced in both cases of GPIIb-specific- and GPIIIa-specific-mAb used. Immunoprecipitation experiments further confirmed that the EDTA-treatment abrogated the antigenicity of GPIIb-IIIa for platelet-associated antibodies in 2 patients. Serum anti-GPIIb-IIIa autoantibodies were detected in 23 out of 57 patients (40%). However, only 7 out of 23 serum anti-GPIIb-IIIa antibodies could be detected with all 3 mAbs. The MACE using EDTA-treated platelets further showed that the features of serum anti-GPIIb-IIIa antibodies were different from those of platelet-associated antibodies even in the same patient. Our data demonstrate that the platelet-associated anti-GPIIb-IIIa antibodies mainly recognize the cation-dependent antigenic determinants on GPIIb-IIIa and that serum anti-GPIIb-IIIa antibodies may contain some components which differ in specificity from platelet-associated antibodies.

Sisters with familial adenomatous polyposis affected with thyroid carcinoma, desmoid tumour and duodenal polyposis

After prophylactic surgery for colonic polyposis, upper gastrointestinal cancer and desmoid tumour are the main causes of death in patients with familial adenomatous polyposis (FAP). Two sisters with FAP who developed multicentric carcinoma of the thyroid, desmoid tumour and duodenal polyposis are presented.

[Applicability of percutaneous endoscopic gastrostomy for enteral nutrition]

As the structure of social changes, there is new attention given to emerging methods of home medical care. In addition to decreasing daily costs and the number of patients admitted to hospital, a patient can receive treatment at home, on the tatami where he feels comfortable. Is this not the ultimate goal of medicine? As a result of home care, a patient's quality of life can be improved, a great step for medicine. A growing option for home feeding system is administration of HEN (home enteral nutrition). Use of HEN will likely increase in the future, however, many problems associated with prescriptions and administrative systems need to be addressed. In this article, the clinical merits and drawbacks associated with PEG (percutaneous endoscopic gastrostomy), a new approach rapidly gaining acceptance will be examined.

Development in mother-infant en face interaction of high-risk newborn infants: a longitudinal follow-up from 0 to 7 months

In order to evaluate mother-infant en face interaction of high-risk infants and their mothers, we followed three dyads from a high-risk group and three dyads from a low-risk group, every 3 weeks from 0 to 30 weeks of corrected postnatal age. The mother-infant en face interaction was analyzed by conditional probability analysis with a lag sequential concept. The main findings of this study were: (1) there was almost no clear difference in the amount of movement between the high-risk group infants and the low-risk group infants; (2) behavioral responsiveness of the high-risk group dyads was unclear, however, behavioral responsiveness of the low-risk group dyads was very clear; and (3) in common to all subjects of the low-risk group, an increasing frequency of responsive mother-infant interaction was found during the postnatal period. However, in the high-risk group, each dyad showed a very different developmental course. The findings suggest qualitative differences in mother-infant en face interactions between the high-risk group dyads and the low-risk group dyads.

An index to predict outcome of surgery for reflux esophagitis based on the AFP classification

Fifteen patients with reflux esophagitis were treated surgically from July 1990 to April 1994. We evaluated these patients using the anatomic-functional-pathologic (AFP) classification both prior to and following the operation. An objective index for surgical outcome was devised. By using the grades Ai, Fj, and Pk, the i2 + j2 + k2 score was determined. The scores ranged from 3 to 22 (mean 9.1 +/- 5.4) prior to the operation. Postoperatively, 12 (80%) of 15 patients showed a complete recovery with a numerical score of 0, and their symptoms also disappeared. The scores of these 12 patients prior to the operation ranged between 3 and 11. However, the other 3 patients did not exhibit a complete recovery. Their scores prior to the operation ranged between 17 and 22, and the symptoms in 2 of these 3 patients persisted following the operation. These results suggest that surgical treatment for reflux esophagitis can be expected to be successful if the preoperative AFP score is less than 11.

Reduced uptake of oxidized low density lipoproteins in monocyte-derived macrophages from CD36-deficient subjects

To clarify the physiological roles of CD36 as an oxidized low density lipoprotein (OxLDL) receptor, we analyzed the monocyte-derived macrophages from normal and two CD36-deficient subjects, since we identified the molecular abnormalities (Kashiwagi, H., Y. Tomiyama, Y. Kosugi, M. Shiraga, R. H. Lipsky, Y. Kanayama, Y. Kurata, and Y. Matsuzawa 1994. Blood. 83:3545-3552; and Kashiwagi, H., Y. Tomiyama, S. Honda, S. Kosugi, M. Shiraga, N. Nagao, S. Sekiguchi, Y. Kanayama, Y. Kurata, and Y. Matsuzawa. 1995. J. Clin. Invest. 95:1040-1046). Scatchard analysis of 125I-OxLDL binding showed a linear plot and the maximum binding was lower by approximately 40% in the macrophages from subjects with CD36 deficiency than those from normal controls. Competition studies showed that the uptake of 125I-OxLDL was suppressed by OKM5, an antibody against CD36, by 53% in normal control macrophages, but not in the CD36-deficient macrophages. After incubation with OxLDL for 24 h, cholesteryl ester mass accumulation was reduced by approximately 40% in the macrophages from CD36-deficient subjects than those from normal controls. These results suggest that CD36 is one of the physiological receptors for OxLDL. Since specific binding of OxLDL was only reduced by approximately 40% in spite of the complete deficiency of CD36, several other receptors also may have some role in OxLDL uptake. Further studies will be needed to assess the quantitative role of CD36 in foam cell formation in vivo.

Monoclonal anticardiolipin autoantibodies established from the (New Zealand white x BXSB)F1 mouse model of antiphospholipid syndrome cross-react with oxidized low-density lipoprotein

OBJECTIVE

Autoimmunity-prone (New Zealand white x BXSB)F1 ([NZW x BXSB]F1) mice have been shown to be useful as a model of antiphospholipid syndrome with myocardial infarction. The aim of this study was to examine the cross-reactivity of anticardiolipin antibody (aCL) derived from (NZW x BXSB)F1 mice with oxidized low-density lipoprotein (ox-LDL), which is closely associated with atherosclerosis.

METHODS

Six monoclonal antibodies (MAb) against CL were established from (NZW x BXSB)F1 mice, and reactivity of aCL with ox-LDL was examined by micro-enzyme-linked immunosorbent assay.

RESULTS

Higher titers of anti-ox-LDL autoantibodies were found in adult (NZW x BXSB)F1 mice compared with other autoimmunity-prone mouse strains (P < 0.01) or a control strain (P < 0.005). There was a significant positive correlation between titers of aCL and those of anti-ox-LDL in (NZW x BXSB)F1 mice (r = 0.79, P < 0.001). Of the 6 MAb against CL, 2 clones that showed beta 2-glycoprotein 1-dependent reactivity also cross-reacted with ox-LDL. Binding of monoclonal aCL to solid-phase cardiolipin was inhibited by ox-LDL, but not by native LDL.

CONCLUSION

We confirmed that aCL derived from (NZW x BXSB)F1 mice can cross-react with ox-LDL. This result suggests that aCL, which is closely associated with lupus-associated thrombosis, may also play an important role in atherosclerotic complications in patients with systemic lupus erythematosus.

Sutureless anastomosis using a biofragmentable anastomosis ring

The biofragmentable anastomosis ring (BAR) is composed of polyglycolic acid and barium sulfate. When used for intestinal anastomosis, the BAR fragments after the anastomosis is established. We used this device in 43 patients. In three patients, the anastomosis with BAR was abandoned due to technical difficulties. A total of 43 anastomoses with BAR were performed in 40 patients. The operations in which BAR was used included right hemicolectomy in 12 patients, transverse colectomy in 7, sigmoidectomy in 11, small bowel resection in 5 and other bowel resections in 8. The time spent for the BAR anastomsis ranged from 7 to 30 min with a mean of 15.2 min, which was significantly shorter than that of conventional hand-sutured anastomosis in 23 cases. The fragmentation and excretion of the BAR occurred from 14 to 49 days later with a mean of 21.8 days. There was only one instance of anastomotic leakage (1/40, 2.5%), which occurred in a patient with a cytomegaloviral infection of the intestine. A postoperative barium enema study in 28 patients showed no passage disturbance through the anastomosis. In conclusion, the anastomosis using BAR is considered to be a simple, safe, and fast method for performing either colonic or small intestinal anastomosis.

Family studies of type II CD36 deficient subjects: linkage of a CD36 allele to a platelet-specific mRNA expression defect(s) causing type II CD36 deficiency

We performed family studies with type II CD36 deficiency. In the Mi. Y family, the proband (YII.1) and his brother (YII.2) displayed a type II deficient phenotype. In the mother (YI.2), binding of the anti-CD36 monoclonal antibody, OKM5, to both platelets and monocytes was reduced as compared to CD36 positive control cells. In the father (YI.1), while OKM5 binding to his platelets was reduced, that of his monocytes was almost the same as normal control monocytes. Analysis of genomic DNA showed that YI.2, YII.1 and YII.2 were heterozygous for a proline90-->serine mutation, and showed that both alleles of YI.1 did not have the mutation. Analysis of CD36 cDNA showed that the Pro90 form of CD36 cDNA could be detected in monocytes, but not in platelets from YII.1 and YII.2. These data indicated that YII.1 and YII.2 could be compound heterozygotes; an allele having a platelet-specific mRNA expression defect(s), which was responsible for the different CD36 expression between their platelets and monocytes, and the Ser90 allele. YI.1 was suggested to be a carrier of the platelet-specific silent allele. The platelet-specific silent allele was linked to a specific genotype of a polymorphic microsatellite sequence in the CD36 gene, supporting our hypothesis that mRNA expression defect(s) occurred at or near the CD36 gene. In a second type II CD36 deficient family, we also obtained results consistent with this hypothesis.

Laparoscope-assisted Billroth I gastrectomy

We performed a distal gastrectomy, including regional lymph node dissection, under laparoscopic observation followed by Billroth I. (B-I) anastomosis using autosuture in five patients with early gastric cancer. We had previously evaluated the technique for reconstructive surgery in animal experiments. Our method was determined to be safe without marked deformation caused by applying the autosuture for gastroduodenostomy. The wound was small, and an almost closed operation was possible. Furthermore, unlike endoscopic mucosal resection or laparoscopic partial resection, a major part of the regional lymph nodes can be extirpated; the lesion site may not be limited to the half of the stomach on the distal side. Our method of distal gastrectomy under laparoscopy is a potentially useful limited operation in patients with early gastric cancer.

Interleukin-1 receptor antagonist in patients with active systemic lupus erythematosus. Enhanced production by monocytes and correlation with disease activity

OBJECTIVE

To evaluate the relationship between the serum concentration of interleukin-1 receptor antagonist (IL-1Ra) and systemic lupus erythematosus (SLE) disease activity, and to investigate the expression of IL-1Ra messenger RNA (mRNA) and its production by monocytes from patients with SLE.

METHODS

Serum IL-1Ra was measured by enzyme-linked immunosorbent assay, and expression of IL-1Ra mRNA was determined by Northern blotting.

RESULTS

Serum IL-1Ra concentrations were significantly higher in patients with active SLE compared with normal subjects and patients with other rheumatic diseases, and showed a strong correlation with SLE disease activity. IL-1Ra mRNA expression in freshly isolated monocytes from patients with active SLE was considerably higher than that in normal monocytes. Moreover, monocytes from patients with active SLE produced increased amounts of IL-1Ra in response to adherent IgG, compared with monocytes from normal subjects.

CONCLUSION

A high serum concentration of IL-1Ra is a pathophysiologic feature of active SLE and a good indicator of disease activity. Functional changes of monocytes, such as increased secretion of IL-1Ra in response to adherent IgG and enhanced expression of IL-1Ra mRNA in freshly isolated cells, may be involved in the enhanced IL-1Ra production in active SLE. High concentrations of IL-1Ra in the circulation and possibly in peripheral lymphoid tissues may influence immunologic and inflammatory features of SLE.

Abnormal processing of the glycoprotein IIb transcript due to a nonsense mutation in exon 17 associated with Glanzmann's thrombasthenia

We analyzed the molecular genetic defect responsible for type I Glanzmann's thrombasthenia in a Japanese patient. In an immunoblot assay using polyclonal anti-GpIIb-IIIa antibodies, some GPIIIa (15% of normal amount) could be detected in the patient's platelets, whereas GPIIb could not (< 2% of normal amount). Nucleotide sequence analysis of platelet GPIIb mRNA-derived polymerase chain reaction (PCR) products revealed that patient's GPIIb cDNA had a 75-bp deletion in the 3' boundary of exon 17 resulting in an in-frame deletion of 25 amino acids. DNA analysis and family study revealed that the patient was a compound heterozygote of two GPIIb gene defects. One allele derived from her father was not expressed in platelets, and the other allele derived from her mother had a 9644C--> T mutation which was located at the position -3 of the splice donor junction of exon 17 and resulted in a termination codon (TGA). Moreover, quantitative analysis demonstrated that the amount of the abnormal GPIIb transcript in the patient's platelets was markedly reduced. Thus, the C --> T mutation resulting in the abnormal splicing of GPIIb transcript and the reduction in its amount is responsible for Glanzmann's thrombasthenia.

Molecular basis of CD36 deficiency. Evidence that a 478C-->T substitution (proline90-->serine) in CD36 cDNA accounts for CD36 deficiency

CD36 deficiency is divided into two subgroups: neither platelets nor monocytes express CD36 (type I deficiency), and monocytes express CD36 in spite of the lack of platelet CD36 (type II deficiency). We have already demonstrated that a 478C-->T substitution (proline90-->serine) in platelet CD36 cDNA predominates in type II deficiency (Kashiwagi, H., S. Honda, Y. Tomiyama, H. Mizutani, H. Take, Y. Honda, S. Kosugi, Y. Kanayama, Y. Kurata, and Y. Matsuzawa. 1993. Thromb. Haemostasis. 69:481-484). In this study, we revealed that monocyte CD36 cDNA from two type II deficient subjects was heterozygous for C478 and T478 form, while platelet CD36 cDNA of these subjects consisted of only T478 form. In a type I deficient subject, both platelet and monocyte CD36 cDNA showed only T478 form. Expression assay using C478 or T478 form of CD36 cDNA transfected cells revealed that there was an 81-kD precursor form of CD36, and that the maturation of the 81-kD precursor form to the 88-kD mature form of CD36 was markedly impaired by the substitution. The mutated precursor form of CD36 was subsequently degraded in the cytoplasm. These results indicate that the 478C-->T substitution directly leads to CD36 deficiency via defects in posttranslational modification, and that this substitution is the major defects underlying CD36 deficiency.

Cyclic thrombocytopenia associated with IgM anti-GPIIb-IIIa autoantibodies

We studied a female patient with cyclic fluctuation in platelet count following splenectomy for autoimmune thrombocytopenia. The cyclical fluctuation appeared to be in phase with her menstrual cycle and her platelet count was low during menses. Bone marrow examinations performed at the peak as well as the bottom of the platelet count showed normal or increased numbers of megakaryocytes. The patient's platelet count increased rapidly after intravenous gamma-globulin (IVIgG) therapy, suggesting that a failure of platelet production is unlikely to account for the cycle. Platelet-associated IgM (PAIgM) was markedly elevated, whereas PAIgG was normal at any stage of the cycle. MACE assay demonstrated that PAIgM contained IgM anti-glycoprotein (GP) IIb-IIIa autoantibodies. Comparison between MACE assay using untreated and EDTA-treated platelets at 37 degrees C demonstrated that the platelet-associated IgM autoantibodies mainly recognized divalent cation-dependent conformation(s) of GPIIb-IIIa. No antibodies were, however, detected in her serum. The levels of IgM anti-GPIIb-IIIa showed an inverse relationship with the platelet count. In spite of the marked increase in platelet count after IVIgG, however, the levels of IgM anti-GPIIb-IIIa remained elevated. These findings suggest that platelet-associated IgM anti-GPIIb-IIIa autoantibodies are of pathogenic significance in this patient.

[Clinical experience and early results of aortic valve replacements with Medtronic Hall 20 A]

We experienced aortic valve replacement for 18 patients (4 male and 14 female, ranging from 40 to 81 years old, mean 64 years old) with small aortic annulus with new small prosthesis. Medtronic Hall 20 A (MH 20 A). The average body surface area was 1.47 m2 (range 1.28 to 1.81 m2). One patient was died of lung cancer at 3 months postoperatively. One nonstructural dysfunction and one low cardiac output syndrome was noted during operation. Sixteen survivors with MH 20 A, showed satisfactory clinical results, except for minor thromboembolism, in 2 patients. The MH 20 A had the same function as that of MH 21 A, already reported. We concluded that aortic valve replacement by Medtronic Hall 20 A prosthesis was usefull for the patient with small aortic annulus.

[Nitroglycerin tape for Raynaud's phenomenon of rheumatic disease patients--an evaluation of skin temperature by thermography]

Topical nitroglycerin has been tried for the alleviation of Raynaud's phenomenon in rheumatic diseases, but its effect is not widely recognized. We evaluated the effect of nitroglycerin tape (NTG tape) for peripheral circulatory failure of 7 patients with rheumatic diseases (4 women and 3 men, aged 35-73 years). The underlying rheumatic diseases included: systemic sclerosis 4 patients, polyarteritis nodosa (PN) 1 patient, cutaneous PN 1 patient and digital microinfarction with pulmonary fibrosis 1 patient. An NTG tape (containing 2.5 mg of nitroglycerin) was applied unilaterally on one forearm or leg, and the change in skin temperature was evaluated by thermography. Skin temperature of the extremities significantly increased at 2 and 3 hours after the application of NTG tape. Feeling of cold and/or pain improved in all patients. Adverse effect was headache in one patient. These results suggest that NTG tape may deserve further use in the treatment of peripheral circulatory failure in patients with rheumatic diseases.

[Atrial pacing with the A-V paceport pulmonary artery catheter]

Atrial pacing is often necessary during cardiac surgery. A total of 20 patients undergoing cardiac surgery were atrially paced with either a multipurpose pulmonary artery catheter (PAC) or an A-V paceport PAC (n = 10 each). Atrial pacing was successful in all the patients before cardiopulmonary bypass. The output threshold was 4.2 +/- 0.7 mA for a multipurpose PAC and 3.8 +/- 0.7 mA for A-V paceport PAC. Atrial pacing with both PAC's was readily performed and useful during cardiac surgery.

[Tissue blood flow of the sigmoid colon for safe anastomosis following ligation of the inferior mesenteric artery]

We examined the tissue blood flow (TBF) of the sigmoid colon to determine which level of inferior mesenteric artery. In 13 patients, TBF of the sigmoid colon was measured in the control state and the clamped state, in which the inferior mesenteric artery (IMA), left colic artery and the rectal were wall clamped. In the clamped state, means of TBF at 10 cm and 15 cm distal to the descend-sigmoid junction were 1.87 +/- 0.77 and 1.10 +/- 0.40, respectively. Mean of TBF at 15 cm was significantly lower than that at 10 cm. In conclusion, TBF which is enough for safe anastomosis reaches as far as 10 cm distal from the descend-sigmoid junction after ligation of IMA. Anastomosis at this level in anterior resection of the rectum is safe in concerning with TBF.

Identification of molecular defects in a subject with type I CD36 deficiency

We performed a molecular analysis of a subject whose platelets and monocytes did not express any cell surface CD36 (designated as a type I CD36 deficiency). Amplification of the 5' half of platelet and monocyte CD36cDNA (corresponding to nucleotide [nt] 191-1009 of the published CD36 cDNA sequence [Oquendo et al, Cell, 58:95, 1989]) showed that two different-sized CD36 cDNAs existed. One cDNA was of predicted normal size, whereas the other was about 150 bp smaller than that predicted for normal CD36 cDNA. Amplification of the 3' region of CD36 cDNA (nt 962-1714) in this subject showed only normal-sized CD36 cDNA. Cloning and nt sequence analysis of the cDNAs showed that the smaller sized CD36 cDNA had 161-bp deletion (from nt 331 to 491), and a dinucleotide deletion starting at nt position 539. The same dinucleotide deletion was also detected in the normal sized CD36 cDNA. Both deletions caused a frameshift leading to the appearance of a translation stop codon. RNA blot analysis and quantitative assay using the reverse transcription-polymerase chain reaction (RT-PCR) showed that the CD36 transcripts in both platelets and monocytes were greatly reduced. Comparison of the determined cDNA sequences with the genomic DNA sequence for the human CD36 gene showed that the dinucleotide deletion was located in exon 5, and that the 161-bp deletion corresponded to a loss of exon 4. PCR-based analysis using genomic DNA showed that this subject was homozygous for the dinucleotide deletion in exon 5. Except for the dinucleotide deletion, we could not find any abnormalities around exon 3, 4, and 5 including the splice junctions. These results suggested that the deletions in CD36 mRNA were likely to be responsible for instability of the transcripts, and the dinucleotide deletion in exon 5 might affect the splicing of exon 4.

[A case of coronary artery bypass grafting without cardiopulmonary bypass in a patient of both coronary ostial stenosis due to Takayasu's arteritis]

A 61-year-old female admitted with the diagnosis of both coronary ostial stenosis & the severe calcified aorta due to Takayasu's arteritis. She underwent coronary artery bypass grafting successfully, using the right internal thoracic artery to RCA & the left internal thoracic artery to LAD, without cardiopulmonary bypass. Coronary artery bypass grafting without cardiopulmonary bypass is one of the useful surgical technique for the patient with the severe calcified aorta due to Takayasu's arteritis.

Demonstration of a marked reduction in the amount of GPIIb in most type II patients with Glanzmann's thrombasthenia

In this study employing a sensitive immunoblot assay, we have characterized GPIIb and GPIIIa in thrombasthenic platelets from seven type II and four type I patients from 10 unrelated families. The amounts of GPIIb and GPIIIa were both markedly reduced in all these patients, and abnormal molecular weight GPIIb or GPIIIa was not detected. In all of four type I patients the amount of GPIIb was much lower than that of GPIIIa. In this study, however, we found that the amount of GPIIb was also lower even in six out of seven type II patients. Immunodepletion of patients' platelets with AP2 (a monoclonal antibody specific for the GPIIb-IIIa complex), AP3 (specific for GPIIIa) or AMF7 (specific for alpha v) further confirmed that GPIIIa existed in excess, and demonstrated that excess GPIIIa were mostly in free form and not associated with GPIIb or alpha v. The reduction of GPIIb may represent an abnormality in GPIIb processing in these type II and type I thrombasthenic platelets. It remains unclear whether these two subgroups represent distinct categories.

[Clinical experiences of granulocyte colony stimulating factor for granulocytopenia after AC bypass]

We have successfully treated 3 cases of granulocytopenia, using Granulocyte Colony Stimulating Factor (G-CSF) after AC bypass surgery. All cases were male, aged 68, 75 & 54 years old, and underwent AC bypass surgery without transfusion except in case 1. Granulocyte cell counts decreased to 135/mm3 on 39th post-operative days (POD) in case 1, 624/mm3 on 13 rd POD in case 2, and 514/mm3 on 20th POD in case 3. In case 1, 300 micrograms of G-CSF was given intravenously for 3 days. In case 2, 100 micrograms of G-CSF for 1 day and 50 micrograms for 3 days was given subcutaneously, and in case 3, 100 micrograms of G-CSF was also given subcutaneously for 2 days. And their granulocyte cell counts all increased within few days. G-CSF is effective for patients with granulocytopenia after AC bypass surgery, but we need more experiences to know the best way of administration.

High-titer antinuclear antibodies, anti-SSA/Ro antibodies and anti-nuclear RNP antibodies in patients with idiopathic thrombocytopenic purpura

The clinical significance of high-titer antinuclear antibodies (ANA) and autoantibodies to cellular antigens such as SSA/Ro and nuclear RNP (nRNP) antigens in idiopathic thrombocytopenic purpura (ITP) was examined in a prospective evaluation of 66 adult patients with chronic ITP. ANA were positive in 29 (44%) of 66 patients with chronic ITP. The titers of ANA were high (1:160 or higher) in 14 of 29 ANA-positive patients. Furthermore, 10 of 66 patients had precipitating antibodies to nuclear antigens; seven patients had anti-SSA/Ro antibodies and the other three had anti-nRNP antibodies. None of high-titer ANA- or precipitating antibody-positive patients developed systemic lupus erythematosus (SLE) throughout the follow-up period of 3 years. In addition, we investigated retrospectively precipitating antibodies in stocked sera from 8 patients. These patients had already precipitating antibodies average of 7.7 years before. None of 8 patients developed SLE or Sjogren's syndrome (SS). These data demonstrate that high-titer ANA and antibodies to SSA/Ro or nRNP antigens are often found in patients with ITP, and indicate that the detection of high-titer ANA or the existence of antibodies to SSA/Ro or nRNP antigens by itself is not enough to identify those patients with ITP who are at risk of developing SLE or SS.