Molecular screening of both the promoter and the protein coding regions in the human ob gene in Japanese obese subjects with non-insulin-dependent diabetes mellitus

OBJECTIVE

Although the molecular mechanism of obesity has been poorly understood, recent studies indicate that leptin plays a critical role in regulating both food intake and body weight. Because obesity decreases the sensitivity to insulin, the human ob gene is presumed to be one of the candidate genes for non-insulin-dependent diabetes mellitus (NIDDM) associated with obesity. Although the protein coding region in the ob gene has been screened for mutations, the promoter region and the non-coding first exon have not yet been studied. We investigated the involvement of the human ob gene, especially mutations at the promoter region and the non-coding first exon, in the development of NIDDM associated with obesity.

SUBJECTS

The study group comprised 60 Japanese obese subjects with NIDDM (body mass index (BMI) 43.6 > or = BMI > or = 26.4, 29.0+/-0.41 (mean+/-S.E.M.)) and 24 obese individuals with impaired glucose tolerance (IGT) (30 > or = BMI > or = 26.4, 27.1+/-0.22).

METHODS

Mutations at both the promoter region and all three exons in the human ob gene were screened by the single-stranded conformational polymorphism analysis. When aberrantly migrated bands were recognized, the PCR-amplified DNA fragment was directly sequenced.

RESULTS

In the protein coding region a silent mutation in the second exon was detected. The non-coding first exon and the about 100 bp 5'-flanking region of the gene which contains a proximal CCAAT/enhancer-binding protein site were screened, but no mutations were found.

CONCLUSION

These results suggest that no mutations in either the promoter region at the about 100 bp 5'-flanking region of the gene, or in any of the three exons, are involved in the development of NIDDM or IGT associated with obesity.

Human leptin receptor gene in obese Japanese subjects: evidence against either obesity-causing mutations or association of sequence variants with obesity

Leptin is an adipocyte-derived blood-borne satiety factor that acts on its cognate leptin receptor (Ob-R) in the hypothalamus, thereby regulating food intake and energy expenditure. To explore whether mutations in the Ob-R gene cause obesity in humans, we have searched for mutations in the gene for Ob-Rb, a biologically active receptor isoform, in obese Japanese subjects. We have also examined associations between such mutants and obesity in the Japanese. Genomic DNAs were used as templates in polymerase chain reaction (PCR) with primers selected to amplify exons 2 to 20 of the human Ob-Rb gene. Direct sequence analysis of the PCR products revealed 7 nucleotide sequence variants (Lys109Arg, Gln223Arg, Ser343Ser, Ser492Thr, Lys656Asn, Ala976Asp, and Pro1019Pro) in the Ob-Rb coding region from 17 obese Japanese subjects with a family history of obesity (BMI 39.3 +/- 8.4 kg/m2). No missense and nonsense mutations were found such as those in Zucker fatty (fa/fa) rats and Koletsky (fa[k]/ fa[k]) rats. Nucleotide substitutions occurred at relatively high frequencies at codons 109, 223, 976, and 1019 (79, 91, 100, and 85%, respectively). Allele frequency of each variant determined by PCR-RFLP and PCR-single strand conformation polymorphism analyses showed no significant differences between 47 obese (BMI 35.1 +/- 6.5 kg/m2) and 68 non-obese (BMI 21.6 +/- 2.2 kg/m2) subjects. The present study represents the first report of sequence variants of the Ob-Rb gene in the Japanese and provides evidence against either obesity-causing mutations or association of sequence variants with obesity in obese Japanese subjects.

Purification and characterization of novel whey glycoprotein WGP-88 which binds to a monoclonal antibody to PAS-4 glycoprotein in the bovine milk fat globule membrane

A monoclonal antibody to the PAS-4 glycoprotein (78 kDa) of the bovine milk fat globule membrane (MFGM) specifically recognized PAS-4, and was named KAS4. A component recognized by KAS4 was found in whey protein, this being a glycoprotein of 88 kDa by SDS-PAGE and named WGP-88. WGP-88 was purified and characterized in comparison with PAS-4. WGP-88 had apparent pI values of 6.45 and 6.39, while those of PAS-4 were 7.39 and 7.35. Neuraminidase digestion shifted the pI values of WGP-88 to 6.57 and of PAS-4 to 7.52. WGP-88 was rich in polar amino residues (44.9 mol%), while PAS-4 was abundant in nonpolar amino acid residues (48.7 mol%). WGP-88 contained 17.1% of carbohydrate and PAS-4 had 7.2%. The results of reductive hydrolysis, N-glycanase digestion, and a lectin blot analysis suggested that N- and O-linked sugar chains were contained in both glycoproteins. WGP-88 and PAS-4 had a different N-terminal amino acid sequence. WGP-88 and PAS-4 respectively inhibited competitively the binding of KAS4 to PAS-4 and WGP-88. Our studies revealed WGP-88 recognized by KAS4 mAb to be a novel whey protein and to have different biochemical properties from those of PAS-4.

Coronary artery bypass grafting of Takayasu's disease with calcified aorta and subclavian artery obstruction

The lesions of Takayasu's disease, which may involve the aorta and major arterial branches, may pose technical difficulties during coronary artery bypass grafting (CABG). Because the aorta is often thick and calcified, the coronary arterial lesion is often located near the coronary orifice, and the internal thoracic arteries may not be suitable for grafting due to the lesions in the subclavian arteries. A 63-year-old man with a known history of Takayasu's disease was referred to our department with chest pain complaint. Coronary angiography revealed obstruction of the left main coronary artery. CT scan showed that he had a thickened and calcified aorta. Aortography showed that both subclavian arteries had obstructive disease. Instead of using ordinary arterial grafts or vein grafts, a piece of prosthetic patch carrying saphenous vein grafts was sewn to the ascending aorta to construct the proximal anastomosis of CABG. Distal anastomosis was made on the left anterior descending artery and the obtuse marginal branch in the usual fashion. The patient showed uneventful recovery, and a postoperative coronary angiogram showed patent grafts and uncomplicated ventricular performance. This technique is useful when the aorta is not suitable for vein graft anastomosis and arterial grafts are not available as in this case with aortitis reported in the paper.

[Destructive spondyloarthropathy of the cervical spine in hemodialyzed patients]

To assess the prevalences and neurological symptoms of destructive spondyloarthropathy (DSA) and other cervical spinal diseases in long-term hemodialysis, a questionnaire survey of the medical histories and subjective sensory-motor symptoms was taken on 191 patients undergoing dialysis for 0.2-23 years (mean 8.6 +/- 6.3) with a mean age of 56.6 +/- 11.8 years (range 23-86). Furthermore, plain radiographic examinations of the cervical spine were carried out in 90% of the patients, and neurologic examinations were also performed on 29 patients. DSA was diagnosed in 18 cases (10%): moderate narrowing of the intervertebral space (NIS-I) in 8, severe narrowing (NIS-II) in 18, ossification of posterior longitudinal ligaments (OPLL) in 6, cervical spondylosis (CS) in 12 and other abnormalities in 6; 104 cases were normal. NIS-I was considered to reflect an early stage of DSA. The age of patients with DSA (mean 61.5 +/- 10.2 years), as well as with CS, was significantly higher than the normal group (52.2 +/- 10.6; p < 0.001), but younger than CS (68.5 +/- 10.0). The duration of dialysis in DSA patients (mean 12.1 +/- 6.0 years) was the longest and significantly longer than normal (7.7 +/- 6.5; p < 0.01) and (:S patients (3.8 +/- 3.0; p < 0.001). Through comparative evaluations of prior histories of the diseases, such as diabetes mellitus, carpal tunnel syndrome, amyloid osteoarthropathy (AOA) and parathyroidectomy, along with large calcification of the nuchal soft tissues on plain films, it was found that DSA, in conjunction with NIS-I, correlated with only AOA (p < 0.05). Subjective sensory symptoms, which consisted chiefly of arthralgic type followed by polyneuritic type, were noted in 60% of all patients and 56% of DSA patients. No significant differences were evident between any two particular groups. The score of subjective motor symptoms of the lower extremities in 5 patients with myelopathy was significantly higher than that in 5 other patients without neurological disorders (p < 0.05). Thirty-eight percent of DSA patients showed myelopathy; the frequency was higher than those of previous similar studies (0 = 5%). In conclusion, this study demonstrated that 1) DSA occurred in 10% of dialysis patients, which was also evident in previous reports (9 = 10%); this prevalence was higher than those of CS or OPLL, 2) DSA correlated with the duration of dialysis and AOA, 3) subjective motor symptoms of the lower extremities could indicate presence of myelopathy whereas subjective sensory symptoms contributed little to differential diagnosis, and 4) a careful neurologic examination can more frequently disclose myelopathy in patients with DSA than so far believed.

Molecular and Crystal Structure of the Complex Composed of 2,3,5-Triphenyltetrazolium Cation and Dichloro-(1,3,5-triphenylformazanato)cobaltate(II) Anion

The molecular and crystal structure of, cobalt(II) complex prepared by the reaction of 1,3,5-triphenylformazan with cobalt dichloride, 2,3,5-triphenyltetrazolium dichloro(1,3,5-triphenylformazanato)cobaltate(II), has been determined by means of X-ray diffraction. The complex crystallized in a triclinic space group P\overline 1, with M r = 728.55, a = 10.214 (3), b = 18.208 (7), c = 9.985 (2) Å, \alpha = 96.44 (3), \beta = 107.92 (2), \gamma = 81.79 (3)°, Z = 2, D x = 1.387 Mg m−3, \mu = 0.683 mm−1, F(000) = 750, R = 0.041, wR = 0.040 and S = 1.40. The complex is composed of a pair of ions, the 2,3,5-triphenyltetrazolium cation and the dichloro(1,3,5-triphenylformazanato)cobaltate(II) anion. The cobalt(II) ion is tetrahedrally coordinated by two N atoms and two chloride ions. One of the chloride ions of the anion has electrostatic intermolecular contacts with the tetrazolium ring of the cation. The conductivity of the complex in nitromethane solution showed complete dissociation of a pair of ions to separate ions.

Carnitine depletion during total parenteral nutrition despite oral L-carnitine supplementation

Carnitine CAR) plays an important role in the beta-oxidation of fatty acids. Less attention. however, has been paid to CAR compared to other nutrients even in total parenteral nutrition (TPN). To examine CAR metabolism during TPN and the effect of simultaneous oral L-CAR supplementation on CAR levels, the blood CAR level was measured in a 3-year-old boy receiving long-term TPN because of short bowel syndrome. Both the total and acyl CAR in the serum were evaluated under various nutritional conditions including oral supplementation of L-CAR. Low CAR concentrations were observed especially when lipid containing TPN regimens were in place. Oral L-CAR supplementation was not sufficient to restore the low CAR levels in the present index patient even when the dose was increased to 120 mg/kg in accordance with the result of the L-CAR absorption test that revealed poor intestinal absorption of this nutrient. Moreover, a markedly low CAR level was measured during the onset of sepsis in the patient, and the blood CAR was depleted when lipid metabolism was activated by lipid loading or sepsis. To date, the late effects of CAR depletion on child growth have not been well examined. It is recommended that the blood CAR level be maintained at normal levels before any prominent manifestations of the deficiency have developed. The intravenous administration of CAR appears to be necessary to supply a sufficient amount of CAR for patients with severe malabsorption.

Myristoyl gelatin as a sealant for Dacron vascular prostheses

Myristoyl gelatin (MG) retains its gel structure at temperatures above body temperature without any crosslinking. As a coating material, MG adheres well to polyester fibers, and the outermost layers of the sealant that are in contact with blood or surrounding tissue become hydrophilic. We produced MG-impregnated knitted Dacron vascular prostheses (MG graft [MGG]) and investigated the usefulness of MG as a sealant by replacing the thoracic aorta of dogs. MGGs (5 cm long with an inner diameter of 10 mm) were implanted in 5 mongrel dogs (10-20 kg), and the grafts were retrieved at intervals of 4 h and 2, 4, 8, and 15 weeks after grafting. There was no thrombus formation on the flow surface of the MGGs, indicating adequate antithrombogenic properties. No resorption of MG occurred until after 2 weeks, and neither immune reaction nor excessive foreign body reaction was noted. Fragmentation of the sealant induced by cell infiltration began to occur at 4 weeks, yet the sealing effect persisted. The organization of MGG was almost complete at 8 weeks. Because of its pliability and effective adhesion to polyester fibers, its antithrombogenicity, and the persistent sealing effect due to delayed biodegradation and resorption, we conclude that MG is an extremely useful sealant for polyester vascular prostheses.

Autoregulation of Pax6 transcriptional activation by two distinct DNA-binding subdomains of the paired domain

BACKGROUND

Pax6 is a transcription factor that plays a central role in eye development. Pax6 contains a DNA-binding domain called paired domain, which consists of a highly conserved N-terminal subdomain and a variable C-terminal subdomain. Recent findings have suggested that both subdomains possess distinct DNA-binding activities.

RESULTS

To understand the mechanism of DNA-binding and transcriptional activation by Pax6 via these subdomains, we employed Pax6 paired domain mutants previously isolated from patients with ocular disorders. Analysis of these mutants by gel shift assay revealed that the N-terminal and C-terminal subdomains can independently bind to their respective cognate sites, P6CON and 5aCON. Results from a luciferase assay, however, showed that the two functional subdomains negatively regulate their transactivation potentials each other. Wild-type Pax6 and its hyperactive variants show different patterns of DNA contact.

CONCLUSION

These results support a new model for the regulation of Pax6 transactivation: When one DNA-binding subdomain binds to its cognate site, the other subdomain also interacts with the flanking sequences nonspecifically, and this interaction constrains its structure to give a reduced level of transactivation.

Role of infrainguinal bypass in Buerger's disease: an eighteen-year experience

OBJECTIVES

The role of bypass to the distal arteries for patients with Buerger's disease (thromboangiitis or TAO) remains controversial because of the high incidence of graft failure. We retrospectively reviewed the results of 71 bypasses to evaluate their efficacy.

MATERIALS AND METHODS

We performed 71 autogenous vein bypasses in 61 patients with TAO. Of the patients, 97% were heavy smokers. The indications for surgery were claudication in 41%, and ischaemic ulcer or gangrene in 59%. Of the bypasses 85% were to the crural arteries or to the arteries below the ankle. The grafts used were 53 single saphenous veins, and 18 venovenous composite grafts.

RESULTS

There were 38 graft failures, the main causes including anastomosis to a diseased artery, disease progression (which occurred in smokers after surgery), and vein graft stenosis. Of 38, 10 were restored to patency by revision surgery. Primary and secondary patency rates were 48.8% and 62.5% at 5 years, and 43.0% and 56.3% at 10 years, respectively. The patency rates of the postoperative non-smoking group was significantly higher than that of the smoking group (66.8% vs. 34.7%, p < 0.05). Thirty-six patients (59%) had successful revascularisation and returned to full-time work. However, of 28 with secondary failure, 11 underwent amputation, while 14 had persistent disabling claudication.

CONCLUSION

Bypass to the distal arteries is an effective treatment for TAO patients, and the long-term patency is quite satisfactory as long as patients stop smoking.

CD44 expression in the developing human retina

BACKGROUND

CD44, the transmembrane adhesion molecule, is expressed in the fetal brain and supposed to mediate neuroglial, interactions. We evaluated the expression and distribution of CD44 in the developing human retina.

METHODS

Four developing human eyes were evaluated at 6, 10, 16, and 21 weeks of gestation, as well as the eyes of one infant and four adults. Frozen sections were immunohistochemically stained with monoclonal antibodies to three human CD44 clones (BU52, F10-44-2, and DF1485) and to vimentin, and antiserum to glial fibrillary acidic protein (GFAP). Specimens were evaluated by light and electron microscopy.

RESULTS

Positive immunostaining for CD44 was first detected at 21 weeks of gestation in the longitudinal fibers that extended from the inner to the outer limiting membrane and around capillary vessels with the simultaneous expression of vimentin and GFAP. Immunoelectron microscopy demonstrated the presence of CD44 on the surface of Müller cells and astrocytes. CD44 was faintly seen in the Müller cells in the periphery and definitely present in the astrocytes in the infant and adult retinas.

CONCLUSION

CD44 was expressed in Müller cells at a late stage of fetal development and in the fetal, infant, and adult astrocytes, which suggests that it is important in the morphogenesis and homeostasis of the neural retina.

[An immunohistochemical study on glycosaminoglycans distribution in the trabeculum of congenital aniridia]

Distribution of glycosaminoglycans in the trabecular tissue was immunohistochemically investigated in 7 congenital aniridia eyes of 5 patients aged 0 to 43 days. Paraffin sections of each specimen were immunohistochemically stained with antibodies to chondoroitin (clone 1-B-5), chondoroitin-1-sulfate (2-B-6), chondoroitin-6-sulfate (3-B-3), dermatan sulfate (6-B-6), and keratan sulfate (5-D-4). The trabecular meshwork and Schlemm's canal in all eyes were absent or not well differentiated. The cornea, trabecular tissue, and iris stroma were negative for chondoroitin immunostaining but positive for chondoroitin-4-sulfate, chondoroitin-6-sulfate, dermatan sulfate and keratan sulfate immunostaining. In the normal anterior segment tissue keratan sulfate is present in the cornea, trabecular tissue, and iris at the fetal stage, and disappears from the iris at the neonatal stage. These findings suggest that the persistence and/or abnormal distribution of keratan sulfate in the anterior segment may play a role in the pathogenesis of congenital aniridia.

Hepatocyte growth factor as a key to modulate anti-ulcer action of prostaglandins in stomach

Although the clinical efficacy of prostaglandins (PGs), especially on gastric mucosal injuries induced by nonsteroidal antiinflammatory drugs, is widely appreciated, their mechanism of action, apart from acid suppression, is quite unclear. In this study, we have established a primary culture system of human gastric fibroblasts and clearly demonstrated that PGs strongly induce the expression of hepatocyte growth factor (HGF) in the fibroblasts, which is mediated by PGE specific receptor, EP2 or EP4. Since HGF facilitates repair and protection of gastric epithelial cells in a paracrine manner, it is assumed that some of the beneficial effects of PGs may be mediated by HGF. To confirm this assumption, we established a simplified in vitro culture gastric mucosal model which consists of gastric epithelial cells and gastric fibroblasts. Using the model, we performed a round wound restitution assay. PGE1 remarkably accelerated restitution which was completely inhibited by anti-HGF antibody, indicating that the action was mediated by HGF. To confirm these in vitro data, we further demonstrated that HGF mRNA expression is downregulated at the edges of nonsteroidal antiinflammatory drug-induced gastric ulcers where PGs should be depleted. In summary, we proposed that gastric fibroblasts are newly recognized targets of PGs, and HGF produced by human gastric fibroblasts may be a key factor for anti-ulcer action of PGs in the stomach.

Subcapsular hematoma of the liver and pylethrombosis in the setting of cholestatic liver injury

We describe a subcapsular hematoma of the liver and pylethrombosis in a patient who developed cholestasis 4 days after severe burn injury. On the 44th hospital day, severe anemia suddenly appeared with no determinable cause. This was the initial manifestation of hepatic hematoma. Cholestatic liver injury of unknown cause lasted throughout the clinical course. The patient subsequently died of hepatic failure 27 months after the burn injury. An autopsy confirmed pylephlebitis and pylethrombosis, which were considered to have contributed to the hepatic failure. This was a rare case of hepatic hematoma and pylephlebitis and pylethrombosis that developed after burn injury.

Evaluation of double filtration plasmapheresis, thermofiltration, and low-density lipoprotein adsorptive methods by crossover test in the treatment of familial hypercholesterolemia patients

A comparative assessment has been made regarding efficacy and safety of the double filtration plasmapheresis (DFPP), thermofiltration (TFPP), and low-density lipoprotein (LDL) adsorptive (PA) methods by making a crossover test on heterozygous familial hypercholesterolemia patients. Treatments by DFPP, TFPP (secondary membrane Evalux 5A), and PA (Liposorber LA-40) were carried out 5 times each, with a 2-week interval, in 5 patients with heterozygous familial hypercholesterolemia. The same plasma separator (Plasmacure PS-60, polysulfone) was used in all cases, and the volume of plasma processed was set at 4 L. High removal rates were obtained of total cholesterol, LDL cholesterol, triglycerides TG, and apolipoprotein B (apoB) by all three methods, and no differences were observed. Lipoprotein (a), apoA-2, apoC-3, fibrinogen, and immunoglobulin M (IgM) showed significantly high removal rates by the DFPP and TFPP methods compared with the PA method. The sieving coefficient of albumin and high-density lipoprotein (HDL) cholesterol at 2 and 4 L of plasma processed exhibited high permeabilities using all three methods. Supplementing albumin was not necessary. An increase of the transmembrane pressure was observed in 1 case treated by DFPP but was not observed when using the TFPP or PA method. No changes were observed in serum interleukin 1beta (IL-1beta) or tumor necrosis factor-alpha (TNF-alpha) before and after treatment by any of the three methods. No remarkable side effects were observed using either the DFPP or TFPP method. The DFPP and TFPP methods showed efficacy and safety that was not inferior to the PA method in conventional LDL apheresis, and the dead-end method of the filter operation without the discarding of plasma was shown to be possible.

Retrospective survey of surgical outcomes on rhegmatogenous retinal detachments associated with atopic dermatitis

OBJECTIVE

To determine the clinical features and surgical outcomes of retinal detachment associated with atopic dermatitis.

METHODS

One hundred twenty-one eyes of 98 patients with atopic dermatitis and rhegmatogenous retinal detachment were surgically treated and followed up for 1 year or longer. Fundus examination data on retinal breaks and detachment, and follow-up data on anatomic reattachment were obtained and compared between phakic and aphakic eyes using the chi 2 test.

RESULTS

Breaks were often multiple and located at the ora serrata (72%) and in the ciliary epithelium (15%). Irregularly shaped breaks (13.5%) and giant breaks (16%) also were seen. Most detachments (71%) were localized and shallow. No significant difference was identified with or without a history of cataract surgery. The prognosis after the initial surgery (reattachment rate, 72%) was unfavorable because of new break formation, but the results of reoperation (reattachment rate, 93%) were as successful.

CONCLUSIONS

Patients with atopic dermatitis may have an abnormality in the anterior retina and ciliary epithelium that predisposes to retinal detachment. Findings suggest a possible traumatic trigger and the need to perform an encircling scleral buckle procedure with widespread retinopexy initially in these patients.

Immunohistochemical studies of glycosaminoglycans in nanophthalmic sclera

BACKGROUND

It has been observed that there may be some connection between scleral collagen changes, glycosaminoglycan (GAG) changes and nanophthalmic uveal effusion. In a previous paper we reported increased dermatan sulfate (DS) and chondroitin sulfate (CS) contents in nanophthalmos sclera using biochemical analysis. In the present work we used immunohistochemical methods to assess the GAG changes in nanophthalmos sclera.

METHODS

Scleral specimens from three nanophthalmic patients and five controls were processed to immunostaining with peroxidase-antiperoxidase (PAP) methods. Monoclonal antibodies for chondroitin (Ch), chondroitin-4-sulfate (C4S), chondroitin-6-sulfate (C6S), DS and keratan sulfate (KS) were used. The specimens were observed under a light microscope.

RESULTS

Nanophthalmos scleral samples exhibited strong KS staining compared with the control specimens. Both the nanophthalmos and the control samples were stained with anti-Ch, anti-C4S, anti-C6S and anti-DS antibodies to the same intensity.

CONCLUSION

Our results suggest that an increased or abnormal distribution of KS may contribute to abnormalities in collagen fibers.

Long-term clinical evaluation of an adsorbent column (BM-01) of direct hemoperfusion type for beta 2-microglobulin on the treatment of dialysis-related amyloidosis

The clinical efficacy and safety of a beta 2-microglobulin (beta 2M) adsorbent column, BM-01, on the treatment of dialysis-related amyloidosis were investigated in 7 hemodialysis patients for more than 6 months. The percent reduction of serum beta 2M was more than 60-70%, and the level at the end of each session was less than 10 mg/L in almost all patients. The amount of beta 2M removed was calculated as more than 200-300 mg/session. The results demonstrated that BM-01 performed very well for removing beta 2M, was capable of maintaining less than 25 mg/L of time average concentration (TAC) for beta 2M, and improved the clinical symptoms. Clinically severe side effects were not observed. We recommend that BM-01 should undergo further evaluation for its usefulness in the long-term treatment of dialysis-related amyloidosis, though treatment with the column may not be successful in preventing the onset of the disease.