Disruption of the HNF-4 gene, expressed in visceral endoderm, leads to cell death in embryonic ectoderm and impaired gastrulation of mouse embryos

Expression of HNF-4, a transcription factor in the steroid hormone receptor superfamily, is detected only in the visceral endoderm of mouse embryos during gastrulation and is expressed in certain embryonic tissues from 8.5 days of gestation. To examine the role of HNF-4 during embryonic development, we disrupted the gene in embryonic stem cells and found that the homozygous loss of functional HNF-4 protein was an embryonic lethal. Cell death was evident in the embryonic ectoderm at 6.5 days when these cells normally initiate gastrulation. As assessed by expression of Brachyury and HNF-3 beta, primitive streak formation and initial differentiation of mesoderm do occur, but with a delay of approximately 24 h. Development of embryonic structures is severely impaired. These results demonstrate that the expression of HNF-4 in the visceral endoderm is essential for embryonic ectoderm survival and normal gastrulation.

Concurrent perilunate dislocation in patients with elbow dislocation: case reports

In three patients with elbow dislocations after falls on an outstretched upper extremity, concurrent perilunate dislocation was found. Closed reduction of the elbow dislocation achieved excellent functional results. Open reduction and internal fixation for perilunate dislocation provided anatomic reduction and satisfactory functional recovery in two patients. In the third, a delay in diagnosis of a perilunate dislocation necessitated proximal row carpectomy at 6 weeks.

The winged-helix transcription factor HNF-3 beta is required for notochord development in the mouse embryo

HNF-3 beta, a transcription factor of the winged-helix family, is expressed in embryonic and adult endoderm and also in midline cells of the node, notochord, and floor plate in mouse embryos. To define the function of HNF-3 beta, a targeted mutation in the HNF-3 beta locus was generated by homologous recombination in embryonic stem cells. Mice lacking HNF-3 beta die by embryonic day (E) 10-11. Mutant embryos examined from E6.5 to E9.5 do not form a distinct node and lack a notochord. In addition, mutant embryos show marked defects in the organization of somites and neural tube that may result from the absence of the notochord. The neural tube of mutant embryos exhibits overt anteroposterior polarity but lacks a floor plate and motor neurons. Endodermal cells are present but fail to form a gut tube in mutant embryos. These studies indicate that HNF-3 beta has an essential role in the development of axial mesoderm in mouse embryos.

Expression of transcription factor HNF-4 in the extraembryonic endoderm, gut, and nephrogenic tissue of the developing mouse embryo: HNF-4 is a marker for primary endoderm in the implanting blastocyst

The expression of HNF-4 (hepatocyte nuclear factor 4) mRNA in postimplantation mouse embryos was analyzed by in situ hybridization. Expression was found in the primary endoderm at embryonic day 4.5 and was restricted to the columnar visceral endoderm cells of the yolk sac from day 5.5 to day 8.5. HNF-4 mRNA was first detected in embryonic tissues at day 8.5, in the liver diverticulum and the hindgut. At later times HNF-4 transcripts were observed in the mesonephric tubules, pancreas, stomach, and intestine and, still later, in the metanephric tubules of the developing kidney. This expression pattern suggests that HNF-4 has a role in the earliest stages of murine postimplantation development as well as in organogenesis.

The application of laparoscopy in colorectal surgery: a preliminary report of twelve cases

BACKGROUND

With the development of video camera imaging system and the improvement of laparoscopic manipulation instruments, laparoscopic surgery has become applicable to many abdominal surgeries. Having completed the feasibility studies of animal model over 10 dogs, we began to apply this new technique in the field of colorectal surgery.

METHODS

From March to July 1993, 12 cases of large bowel resection were performed with laparoscopy. Operations performed included seven cases of laparoscopy-assisted right colectomy (LARC), three cases of laparoscopic abdominal-perineal resection (LAPR), one case of laparoscopic low anterior resection (LLAR) and one case of laparoscopy-assisted subtotal colectomy. Five cases received operation due to diverticular disease, three due to rectal carcinoma, three due to broad villous adenoma and one due to lipoma over ileocecal region.

RESULTS

The average operation time for LARC was 4 hours and 50 minutes, and for LAPR was 6 hours and 35 minutes. Operation time required decreased substantially as the number of laparoscopic surgery performed increased. The average post-operative length of stay was 5.5 days for LARC and 11.5 days for LAPR. Most of the patient started diet intake on the third day after surgery. There was no major complication. Only two cases developed minor complications of subcutaneous hematoma over trocar insertion site and minor wound infection.

CONCLUSIONS

Laparoscopic technique can feasibly be employed in certain cases of colorectal surgery, although it is rather complicated and requires longer learning curve than other laparoscopic procedures. Therefore, surgeons should take it most caution while carrying out this procedure. Experimental trials over animal model is also highly recommended before clinical practice.

Tuberculous tenosynovitis of the wrist mimicking de Quervain's disease

We describe a rare case of tuberculous tenosynovitis involving the first dorsal compartment at the wrist mimicking de Quervain's disease. Differentiation between tuberculous infection and de Quervain's disease is important since corticosteroid injection, appropriate in the latter, is detrimental in tuberculous tenosynovitis. Early culture and biopsy in suspicious cases provide accurate diagnosis.

[Disseminated intravascular coagulation--a case report]

A 31 year-old T1PoAoL1 female developed the early Disseminated Intravascular Coagulation (DIC) signs after cesarean section. The patient had recovery completely after transabdomen total hysterectomy (TAH) and blood products transfusion. Case presentation, literature review, possible pathogenetic mechanism and treatment of DIC were discussed.

Enzyme immunoassay for prostate-specific antigen and its diagnostic application in prostate cancer

The purpose of this study was to develop a reliable screening test for prostate cancer. Monoclonal antibodies specific to the prostate-specific antigen (PSA) were generated with an improved hybridoma technique. The hybrid cells were initially cultured in a semisolid medium containing methylcellulose and later transferred to a liquid medium for further subculture. Thirty-six out of a total 1,250 recovered colonies were shown to exhibit a high affinity to PSA by radioimmunobinding assay. Eight hybrid cell lines which secreted either IgG1 or IgG2a antibodies of a high affinity and specificity were established for evaluation. The association constants between PSA and these monoclonal antibodies were shown to range from 1 x 10(9) to 5 x 10(9) M-1. From the results of a matrix cross-matching procedure, pairs of monoclonal antibodies were identified and the corresponding epitopes assigned, and most of them could also be paired with rabbit anti-PSA in a typical sandwich enzyme immunoassay. The designated EIA procedure was performed over 90 minutes at room temperature in a two-stage incubation protocol with a sensitivity of 0.4 ng/mL. The EIA kit was shown to have little cross-reactivity with thyroid stimulating hormone, alpha-fetoprotein, carcinoembryonic antigen and prostate acid phosphatase. Preliminary evaluations with clinically defined patients' sera revealed that proper selections of antibody pairs in sandwich immunoassays are crucial to the adequate performance of the EIA kits.

Binding and growth-stimulation of cervical cancer cell lines by prolactin

Two cervical cancer cell lines CC7-T and Si-Ha were employed to observe the relationship between cervical cancer and prolactin. By immunocytochemical and indirect immunofluorescent assays using two prolactin monoclonal antibodies PRL-149 and PRL-151, both cell lines with added prolactin (10 ng/mL) were noted to be positive for PRL-151, but negative for PRL-149. The control cell lines from ovarian cancer and the myeloma lines were both stained negative. By using MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, it was noted that CC7-T and Si-Ha grew better in the presence of various added concentrations of prolactin, ranging from 0.1 to 1,000 ng/mL, suggesting that prolactin may enhance the growth of cervical cancer. The degree of stimulation appears to depend on cell differentiation. However, prolactin levels in the cultured supernatant were undetectable by the enzyme immunoassay (EIA) method. We postulate that prolactin can bind and stimulate the growth of some cervical cancer cell lines, probably through the prolactin receptor rather than by autocrine regulation.

Superior mesenteric artery syndrome as a complication in hip spica application for immobilization: report of a case

A 10-year-old girl who had a pelvic and femoral osteotomy for congenital dislocation of her right hip was immobilized with a hip spica. On the 28th postoperative day, she had upper abdominal pain, distention and bilious vomiting. An upper GI series demonstrated complete obstruction of the duodenum at the third portion of the duodenum in a supine position; however, the barium passed the obstruction site slowly when the patient assumed a lateral or prone position. She was successfully treated conservatively with nasogastric decompression, fluid replacement, proper positioning and hyperalimentation. Superior mesenteric artery syndrome is a rare complication in patients immobilized in a body cast or hip spica. Early diagnosis and proper treatment usually leads to an uneventful convalescence.

Sciatica caused by piriformis muscle syndrome: report of two cases

The diagnosis of piriformis muscle syndrome, an unusual cause of sciatica, is difficult. However, with the advancement of imaging techniques, it has become clear that the condition is not just clinical speculation, but is a definite entity. We report on two cases with piriformis muscle syndrome, diagnosed on the basis of: a history of sciatica; physical findings, such as a tender point at the sciatic notch and around the piriformis muscle by palpation of the gluteal region, and by a digital pelvic examination; and computed tomography (CT) to demonstrate hypertrophy of the piriformis muscle. In both cases, a tenotomy of the piriformis muscle at the greater trochanter relieved entrapment of the sciatic nerve and gave satisfactory results. Since local tenderness at the piriformis muscle is the most reliable physical finding, a pelvic examination is recommended in the evaluation of suspected cases of piriformis muscle syndrome. CT is helpful in showing hypertrophy of the piriformis muscle. Detailed history taking, a careful physical examination, and versatile use of CT or magnetic resonance imaging can lead to an early, accurate diagnosis and proper treatment.

Murine chromosomal location of four hepatocyte-enriched transcription factors: HNF-3 alpha, HNF-3 beta, HNF-3 gamma, and HNF-4

The genes for rat hepatocyte nuclear factors 3 and 4 (HNF-3 alpha, HNF-3 beta, HNF-3 gamma, and HNF-4) have been mapped in mouse by analysis of restriction fragment length polymorphisms in interspecific backcross mice. These hepatocyte-enriched transcription factors are positive-acting transcription factors with binding sites in regulatory regions of many genes expressed in hepatocytes. Both HNF-3 alpha, beta, and gamma and HNF-4 are also expressed in intestine. They have recently been implicated as potential participants in endodermal development from early gut cells because of their close homology to Drosophila genes, which themselves are expressed in the developing gut. Despite having similar functional roles and highly conserved DNA binding domains, the three loci from the Hnf-3 family of genes mapped to three different mouse chromosomes, suggesting that the Hnf-3 family has become widely dispersed during evolution and implying the necessity for independent activation of each member of the HNF-3 family.

Late neuropathy in chronic dislocation of the radial head. Report of two cases

Two patients developed ulnar and median neuropathy 15-20 years after anterior dislocation of the radial head had been diagnosed in childhood. Anterior dislocation of the radial head should not be considered innocuous. Open reduction with reconstruction of the annular ligament may be indicated.

Computed tomography in diagnosis of septic sacroiliitis: report of three cases

Disorders of the sacroiliac joint are often overlooked during an initial physical examination because the patient is usually in a supine position and the posteriorly located joint is not accessible. Local pain and tenderness at the sacroiliac joint on lateral compression of the pelvis, together with Gaenslen and Fabere maneuvers, may direct the physician's attention to the joint. However, these symptoms are not specific or pathognomonic. Unusual presentation of septic sacroiliitis, which does not show radiologic changes during the early stages, may mimic gluteal, lumbar disc or intra-abdominal syndromes, leading to unnecessary abdominal exploration or lumbar discectomy. Computed tomography (CT), with its superb delineation of osseous, synovial and peri-articular structures, was applied to diagnose septic sacroiliitis in three patients. In Patient 1, septic arthritis and juxta-articular osteomyelitis with sequestrum formation were demonstrated by CT four weeks before abnormalities were shown on a roentgenogram. In Patients 2 and 3, inflammatory processes affected the synovium and peri-articular muscles; thus, abnormalities were shown by CT but not by a roentgenogram. We consider CT to be helpful and superior to conventional radiography in the diagnosis of septic sacroiliitis.

Micronucleus formation in peripheral-blood lymphocytes from smokers and the influence of alcohol- and tea-drinking habits

In recent years, studies on the genotoxic effects of smoking and its modifying factors have been widely followed with interest. In this report, frequencies of micronuclei (MNF) in peripheral-blood lymphocytes in 220 healthy smokers have been detected by the micronucleus test by finger-skin puncture, which needs only 1 to 2 drops of peripheral blood. On the basis of analysis of matched-pair data, the modifying effects of alcohol and tea are discussed. Our results show that (I) smoking significantly increases MNF in lymphocytes as compared with healthy non-smokers (p less than 0.01); (2) alcohol significantly increases MNF in smokers (p less than 0.01); (3) tea decreases MNF induced by smoking (p less than 0.01). Therefore, the anti-carcinogenic role of tea merits further study.

Transcriptional regulation of the human cholesterol 7 alpha-hydroxylase gene

As an initial step toward understanding the transcriptional regulation of cholesterol 7 alpha-hydroxylase (CYP7) in man, we isolated and functionally characterized the 5'-flanking region of the human CYP7 gene. The nucleotide sequences of the first exon and 1.6 kb preceding the exon were determined and found to contain a TATA box at position -30, a modified CAAT box at position -92, three potential hepatocyte nuclear factor 3 (HNF-3) recognition sites at nucleotides -316, -288, and -255, respectively, and a modified sterol response element at position -271. DNA sequences containing 1.3 kb of the 5'-flanking region and 29 nucleotides of the first exon were linked to the chloramphenicol acetyltransferase gene and transiently transfected into several cell lines. Promoter activity was very strong in the human hepatoma cell line HepG2 but absent in cells of nonhepatic origin. Mutational analysis of the promoter identified several regions that function in the transcriptional regulation of CYP7. Introduction of a fragment containing the region from -432 to -220 upstream of a heterologous promoter, in either orientation, resulted in a tremendous stimulation of activity in HepG2 cells. DNase I footprint analysis identified three regions within this fragment which were protected from digestion. The overexpression of HNF-3 in HepG2 cells resulted in a 4-fold stimulation of CYP7 transcriptional activity. We suggest that the region between -432 and -220 functions as a cell-specific enhancer whose activity is controlled, in part, by HNF-3.

Trend of large bowel tuberculosis and the relation with pulmonary tuberculosis

From 1965 to 1989, 60 cases of large bowel tuberculosis among 116 cases of abdominal tuberculosis are reviewed and analyzed. Lesions located in the cecum or ileocecal region were found in 49 of the 60 cases. Most of the patients (50/60) received surgical intervention, but the definite diagnoses had never been proved until surgery. The diagnoses were proved by histopathologic examination in these 50 cases. Antituberculosis medications were given for at least nine months in all patients. Twenty-nine of the 50 patients who received operations had primary anastomosis during the operations, and no leakage occurred. Evidence of pulmonary tuberculous lesions could be found in 40 of the 60 cases. Positive findings of tubercle bacilli in sputum smear or culture were noted in 13 cases. The positive rate of sputum examinations decreased during 1980 to 1989; 25.6 percent (10/39) were positive from 1965 to 1979 and 14 percent (3/21) were positive from 1980 to 1989. In the meantime, there was a steady decline in the cases of large bowel tuberculosis in the most recent few years. An antituberculosis program has been carried out in the past 40 years with remarkable effect in the Taiwan area, but the possibility of intestinal tuberculosis still exists. The authors suggest that surgeons keep tuberculosis in mind when they are dealing with patients who suffer from intestinal obstruction of unknown origin with the suspected findings of pulmonary tuberculosis in chest x-ray films.

[Effects of pseudolaric acid B on blood flows of endometrium and myometrium in pregnant rats]

Effects of pseudolaric acid B (PB) on endo- and myo-metrial blood flows were measured by hydrogen gas clearance technique in 336 pentobarbital-anesthetized rats divided into control and 2 medicated groups (ig PB 20 and 30 mg.kg-1 on d 7-9 of pregnancy). Measurements of endo- and myo-metrial blood flows were done on d 7-14 of pregnancy. Results showed that the endo- and myo-metrial blood flows were reduced by 33-66% and 30-65% respectively, vs ig 1% CMC 0.5 ml (P less than 0.01). Uterine weight during d 10-14 of pregnancy stopped gain. The systemic arterial pressure remained relatively unchanged. It is concluded that PB causes a significant decrease of blood flow in both endo- and myometrium, which is accounted as the most important cause of embryo's death.

Phosphate glass cement bone graft

The objective of this study was to prepare cement-forming substances from phosphate glasses for use as a bone graft. The glass-forming system of CaO-SrO-Na2O-P2O5 was explored and ten phosphate glasses were prepared of varying compositions. Cements were made by reducing the glass to powders and reacting them with a water solution of calcium hydroxide or phosphoric acid. The cements were evaluated by X-ray diffraction, electron microscopy, density and porosity measurements, pH change during reaction and solubility in water. Because of the water solubilities of these cement materials, they may be useful as bone grafts containing drugs such as antibiotics which would be slowly released as the graft material degrades.

Changes in Cytokinins before and during Early Flower Bud Differentiation in Lychee (Litchi chinensis Sonn.)

Lychee (Litchi chinensis) has been analyzed for cytokinins in buds before and after flower bud differentiation, using reversephase high performance liquid chromatography in combination with Amaranthus bioassay and gas chromatography-mass spectrometry-selected ion monitoring. Four cytokinins, zeatin, zeatin riboside, N(6)-(delta(2)-isopentenyl)adenine, and N(6)-(delta(6)-isopentenyl) adenine riboside, were detected in buds. There was an increase of cytokinin activity in the buds during flower bud differentiation. In dormant buds, the endogenous cytokinin content was low, and the buds did not respond to exogenous cytokinin application. Application of kinetin promotes flower bud differentiation significantly after bud dormancy. These results are interpreted as an indication that the increase in endogenous cytokinin levels during flower bud differentiation may be correlative rather than the cause of flower bud initiation.

The different tissue transcription patterns of genes for HNF-1, C/EBP, HNF-3, and HNF-4, protein factors that govern liver-specific transcription

The transcription factors that act in hepatocyte-specific gene expression include proteins that are present mainly in liver cells (HNF-1/LFB1, C/EBP, HNF-3, HNF-4) (HNF, hepatocyte nuclear factor; C/EBP, rat enhancer binding protein) and proteins that are widely distributed (AP-1, NF-1, NF-Y/ACF). We show here that the genes encoding each of these liver-enriched factors exhibit different patterns of transcriptional control in different tissues. In addition, there were several instances in which transcription was detected (e.g., for HNF-1) when no mRNA or specific DNA binding protein was found, suggesting the importance of posttranscriptional control in some instances for these factors. These experiments identify C/EBP, HNF-3, and HNF-4, and perhaps also HNF-1, as targets for the study of cascades of transcriptionally controlled transcription factors in differentiated cells.

Hepatocyte nuclear factor 3 alpha belongs to a gene family in mammals that is homologous to the Drosophila homeotic gene fork head

By analysis of cDNA clones that cross-hybridized with a portion of the cDNA encoding the recently described rat protein hepatocyte nuclear factor 3 alpha (HNF-3 alpha, previously called HNF-3A), we now describe two additional members, HNF-3 beta and HNF-3 gamma, of this gene family. A 110-amino-acid region in the DNA-binding domain of this family is not only very highly conserved in rodents (HNF-3 alpha, -3 beta, and -3 gamma are identical in 93 of 110 amino acids in this region) but also in Drosophila where the homeotic gene fork head has 88 of the 93 residues that are identical in the three rat genes. The HNF-3 family in rodents is expressed in cells that derive from the lining of the primitive gut; some of the embryonic Drosophila cells in which fork head is expressed also give rise to gut and salivary glands. Thus, it appears that this gene family, the DNA-binding portion of which is unlike that of any previously recognized DNA-binding proteins, may contribute to differentiation of cells in internal organs in both vertebrates and invertebrates.

Phosphorylation of the epidermal growth factor receptor at threonine 654 inhibits ligand-induced internalization and down-regulation

To assess the functional significance of phosphorylation of the epidermal growth factor (EGF) receptor at Thr654, we compared the effects of 12-O-tetradecanoyl-13-acetate (TPA) on ligand-induced internalization and down-regulation between wild-type and mutant receptors that contain an alanine substitution at position 654. Activation of protein kinase C with TPA blocked EGF-induced internalization and down-regulation of Thr654 receptors and inhibited in vivo tyrosine kinase activity by 80%. TPA did not inhibit transferrin receptor internalization or constitutive EGF receptor internalization, suggesting that protein kinase C activation inhibits only the ligand-induced process. Inhibition by TPA of induced internalization, down-regulation, and kinase activity required threonine at position 654 since full-length Ala654 EGF receptors were significantly resistant to TPA inhibition of these ligand-induced activities. However, C'-terminal truncation further enhanced this resistance to TPA inhibition. The EGF-dependent internalization of kinase-inactive receptors truncated at residue 1022 was also impaired by TPA in Thr654 receptors, but not in Ala654 receptors, indicating that phosphorylation at Thr654 also interferes with tyrosine kinase-independent receptor activities. We conclude that the dominant regulatory effect of protein kinase C on the EGF receptor is mediated through phosphorylation at Thr654 which effectively inactivates the receptor. The submembrane region of the EGF receptor appears to regulate transmission of conformational information from the extracellular ligand-binding site to the cytoplasmic kinase and regulatory domains.

[Effects of lidocaine cervical epidural blockade on respiratory function]

Cervical epidural anesthesia with 2% lidocaine has been shown to reduce ventilatory capacity in patients with normal lungs by Dr. Bromage. It is important to evaluate the respiratory effect of this technique which may induce intercostal and phrenic nerve paralysis. After institutional approval and informed content had been obtained, 50 patients undergoing OR & IR of upper limbs, mean age 24 +/- 4 yrs mean weight 65 +/- 6 kg, ASA status I-II without preoperative pulmonary dysfunction were studied. C7-T1 intervertebral space was identified by the hanging-drop technique using a 16G Tuochy needle. A catheter was inserted cranially to a distance of 12 cm. Pulmonary function measurement and arterial blood gas data were obtained before and 20', 50', 105' min after injection of 12 ml 2% plain lidocaine. The anesthesia levels were between C3-T3 and obtained at 13 +/- 2 min. Mean arterial blood gas analysis showed mild respiratory acidosis at 20 min (PaCO2: 46.0 +/- 3.5 mmHg). The measured values of IVC, VC, FVC, FEV1, PEF, when compared with control values were decreased over 15.60% of control values and 20% of predicted data at 20 min. The ratio of FEV1/VC, FEV1/FVC were still within normal limit (greater than 80%). The result was significantly compatible to the criteria of mild type of pulmonary function test. No respiratory distress was complained of and only cause little change of arterial blood gas.(ABSTRACT TRUNCATED AT 250 WORDS)

Ulnar variance and Kienböck's disease. An investigation in Taiwan

The correlation between negative ulnar variance and the occurrence of Kienböck's disease was evaluated in Taiwan. Two groups of subjects were studied. The first group consisted of 1000 normal subjects and the second of 18 patients with Kienböck's disease. Student's t-test was used to evaluate the significance of the difference between this and other published series. The mean was 0.313 mm in Group 1 and -1.222 mm in Group 2. The percentage with significant negative ulnar variance (the distal ulnar was at least 2 mm shorter than the radius) was 6.0% in Group 1 and 55.6% in Group 2. The difference between the two groups was significant. The mean ulnar variance of normal subjects in Taiwan differed significantly from the variance in Swedes and American blacks but not American whites. In Chinese patients with Kienböck's disease, the ulnar variance was predominantly negative, and the distribution of ulnar variance was similar to that of Swedish or American white patients. This study confirmed the association between negative ulnar variance and the occurrence of Kienböck's disease. This supports Hultén's hypothesis that negative ulnar variance may predispose certain individuals to the occurrence of Kienböck's disease.

Analysis of deletions of the carboxyl terminus of the epidermal growth factor receptor reveals self-phosphorylation at tyrosine 992 and enhanced in vivo tyrosine phosphorylation of cell substrates

The human epidermal growth factor receptor (EGFR) contains a large C' terminus distal to the protein tyrosine kinase domain that is conserved among members of its extended gene family. To investigate the C' terminus, a series of mutant EGFR cDNAs encoding progressive C'-terminal deletions were prepared and expressed in null recipient B82L cells. In vivo self-phosphorylation was retained in receptors truncated to residues 1052 and 1022 which lack the three identified sites of tyrosine self-phosphorylation. Receptors truncated to residue 991 did not undergo in vivo self-phosphorylation. Purified 1022 truncated receptor was self-phosphorylated to the extent of 1 mol of phosphate/mol of receptor protein. The deduced additional site of tyrosine self-phosphorylation at residue 992 was confirmed by tryptic phosphopeptide mapping and protein sequencing. EGFRs deleted to give C'-terminal residues 1052, 1022, 991, and 973 exhibited enhanced EGF-stimulated tyrosine phosphorylation of cell substrates in vivo, whereas deletion at residue 944 abolished all detectable EGF-stimulated protein tyrosine phosphorylation. These results indicate that ligand-induced self-phosphorylation is limited to the C' terminus of the EGFR and suggest that this region of the holoreceptor has an inhibitory function.

Restoration of elbow flexion by latissimus dorsi myocutaneous or muscle flap

Six patients with flail elbow as a consequence of brachial plexus injury or traumatic loss of arm muscles underwent bipolar transposition of latissimus dorsi myocutaneous or muscle flaps to the biceps brachii to restore elbow flexion. The muscle strength achieved was 1.5-2.5 kg and the total range of active excursion is about 95 degrees. The muscle strength is sufficient to carry out most of the activities of daily life but insufficient to achieve active supination or to perform heavy manual work. Elbow flexion of more than 120 degrees is necessary for the affected hand to reach the mouth and should be one of the goals of the operation. Versatile use of the myocutaneous flap facilitates skin closure and improves the contour of the arm.

Pigmented villonodular synovitis of flexor tendon sheath at wrist causing pseudo-carpal-tunnel syndrome: report of a case

A 27-year-old male patient, a machinist, had median neuropathy after a minor contusion on his right wrist and underwent carpal tunnel release under the impression of carpal tunnel syndrome five years ago. However, symptoms persisted and a small palmar nodule was found one year later. This slow-growing palmar nodule was locking the flexor tendon and the carpal tunnel was re-explored. At the second operation, the nodule was found to be a pigmented villonodular synovitis of the flexor tendon sheath at the palm. After excision of the lesion, the patient became symptom free. After three years, no recurrence was noted. Exploration of the carpal tunnel is recommended when median neuropathy of the wrist responds poorly to conservative treatment or to previous surgical release of the transverse carpal ligament. Although carpal tunnel release is not a difficult procedure, the pathology has to be checked carefully, so that even a small nodule within or near the carpal tunnel is not neglected, as in this case.

Changes of mercury contents in hair of Chinese scholars after they came to Japan

In April 1988, 49 Chinese scholars came to Japan for one year medical training. Their hair samples were collected in June 1988 and March 1989 for analyses of mercury. After they lived in Japan for nearly one year, the mean total-Hg contents in hair were increased from 0.82 microgram/g to 1.96, and those of methyl-Hg in hair, from 0.19 microgram/g to 0.32, both with significant differences (p less than 0.01). It is suggested that Japanese foods, especially the fish, might be the responsible factor in increasing the mercury contents in their hair.

Functional independence of the epidermal growth factor receptor from a domain required for ligand-induced internalization and calcium regulation

We have located the distal boundary of the tyrosine kinase domain of the EGF receptor and have identified a distinct sequence in the C' terminus required for EGF-dependent receptor internalization, leading to receptor down-regulation and degradation. Within this receptor domain, an 18 amino acid highly negatively charged region of predicted helical structure is required both for endocytosis via a high-affinity, saturable pathway and for ligand-stimulated increases in cytosolic calcium. In contrast to kinase-inactive, internalization-competent receptors, kinase-active, internalization-defective receptors effectively signaled gene transcription, morphological transformation, and growth. These observations support the hypothesis that mitogenic responses to EGF are mediated by activation of the intrinsic protein tyrosine kinase activity of the membrane-bound receptor, with ligand-induced internalization serving to terminate the signal.

Medial gastrocnemius hematoma mimicking deep vein thrombosis: report of a case

Tennis leg, strain of the medial head of the gastrocnemius muscle, may follow a trivial trauma in athletic and nonathletic activities. Complete or partial tears of the musculotendinous unit may result in a hematoma. Clinical manifestations of gastrocnemius hematoma in a 64-year-old man with local swelling, pain and tenderness that was aggravated by passive dorsiflexion of the ankle joint, mimicked deep vein thrombosis. Failure to appreciate the precedent trivial trauma and the localized swelling and ecchymosis led to delayed diagnosis and inappropriate heparinization. The definite diagnosis was established by CT scan which revealed a local soft tissue mass within the gastrocnemius consistent with a hematoma. A compartment syndrome developed the day after heparinization and was adequately treated by discontinuation of heparin, aspiration and rest. Differentiation between tennis leg and deep vein thrombosis is of paramount importance, since the etiology, treatment and prognosis of these two clinical entities are quite different. Venography is recommended as specifically diagnostic for deep vein thrombosis while CT scan for gastrocnemius hematoma.

The roles of hemorrhoidectomy and lateral internal sphincterotomy in the treatment of hemorrhoids--clinical and manometric study

To compare the clinical effect of lateral internal sphincterotomy with hemorrhoidectomy and to examine the change of anal pressure before and after these two treatments, manometric study and clinical symptoms were assessed in 56 patients with hemorrhoids. These patients were randomly allocated to one of the two treatment groups. Another twenty-seven persons with sex and age match were also studied as the normal control. There was no significant difference between the mean resting anal pressure (RAP) of the controls (72.56 +/- 11.93 mmHg) and the hemorrhoid group (75.82 +/- 8.38 mmHg). Thirty-one patients received hemorrhoidectomy and there was no significant reduction of RAP postoperatively. The mean resting anal pressure of the 25 patients receiving lateral internal sphincterotomy was reduced postoperatively (75.1 +/- 9.85 mmHg VS. 70.24 +/- 7.77 mmHg). Although lateral internal sphincterotomy did reduce the anal pressure, the clinical outcome was better in hemorrhoid group. We consider hemorrhoidectomy as the optimal choice in these two kinds of treatment. Change of anal pressure may not play such an important role in the pathogenesis of hemorrhoids.

Activity of agricultural chemicals to modify mitomycin C induced growth inhibition of Bacillus subtilis in the rec assay

Rec assay of agricultural chemicals, MCPA-E, MCPA, CNP and PCNB was conducted. It was found that MCPA-E and MCPA accelerated the growth-inhibition originally induced by Mitomycin C in the rec- strain.

Alteration of epidermal growth factor receptor activity by mutation of its primary carboxyl-terminal site of tyrosine self-phosphorylation

The epidermal growth factor (EGF) receptor, which exhibits intrinsic protein tyrosine kinase activity, undergoes a rapid, intramolecular self-phosphorylation reaction following EGF activation. The primary sites of tyrosine self-phosphorylation in vivo are located in the extreme carboxyl-terminal region of the molecule, principally Tyr-1173. To test the biological and biochemical consequences of this EGF receptor self-phosphorylation, we made the mutation Tyr----Phe-1173. Membranes containing the mutated receptor exhibited an ED50 for EGF activation of tyrosine kinase activity equivalent to control receptor at both high and low substrate levels, but exhibited reduced basal and EGF-stimulated tyrosine kinase activity at low, non-saturating substrate levels. The Tyr----Phe-1173 mutant possessed high affinity EGF binding and could still self-phosphorylate other tyrosine sites in an intramolecular fashion with a low Km for ATP (200 nM), suggesting that this alteration did not grossly change receptor structure. When EGF-dependent growth of Chinese hamster ovary cells expressing comparable levels of control or mutant EGF receptor was measured, the ability of the mutant receptor to mediate cell growth in response to EGF was reduced by approximately 50%, yet both receptors exhibited a similar affinity and ED50 for EGF. These results support the concept that this self-phosphorylation site can act as a competitive/alternate substrate for the EGF receptor, and that this region of the molecule is important in modulating its maximal biological activity.

Ligand-induced endocytosis of the EGF receptor is blocked by mutational inactivation and by microinjection of anti-phosphotyrosine antibodies

Early events in ligand-induced endocytosis of the EGF receptor have been examined. A mutant EGF receptor devoid of intrinsic protein-tyrosine kinase activity bound EGF and dimerized normally yet failed to undergo ligand-induced internalization. Immunofluorescence microscopy revealed that receptors lacking kinase activity failed to undergo the ligand-induced internalization characteristic of receptors with kinase activity. Monoclonal anti-phosphotyrosine antibodies effectively inhibited phosphorylation of exogenous substrates in vitro and, when microinjected into cells containing active EGF receptors, prevented internalization of the receptor when cells were subsequently challenged with EGF. These results point to a crucial role for the kinase activity of the EGF receptor in the process of ligand-induced endocytosis of receptors, and imply that a phosphorylated substrate(s) is required.

Requirement for intrinsic protein tyrosine kinase in the immediate and late actions of the EGF receptor

The epidermal growth factor (EGF) receptor is a transmembrane glycoprotein of relative molecular mass 170,000 with intrinsic ligand-dependent protein tyrosine kinase activity. Binding of EGF to its receptor activates a number of immediate biochemical processes, such as alterations of intracellular free calcium, pH, and increased transcription of several responsive genes, which usually culminate many hours later in DNA replication and cell division. Abolishing the tyrosine kinase activity of three related oncogenes, v-src, v-mos, and v-fps, eliminates their capacity to transform cell. Several reports have suggested that specific aspects of EGF receptor function are independent of the intrinsic tyrosine kinase activity; however, these studies used an antibody against EGF receptor which failed to activate phosphorylation of exogenous substrates and an insertional mutation in the EGF receptor tyrosine kinase domain which had not been shown to abolish protein kinase activity in cells. Because many transmembrane receptors interact with intrinsic membrane proteins to activate second messenger systems, it is important to resolve experimentally whether mechanisms, in addition to activation of the intrinsic tyrosine kinase activity, mediate some EGF actions. From functional analyses of an EGF receptor containing a single amino-acid mutation at a site required for phosphate transfer from ATP, we conclude that the tyrosine kinase activity of the EGF receptor is essential for the diverse biochemical effects of EGF, including rapid alterations in intracellular calcium, activation of gene transcription, receptor down-regulation and the ultimate stimulatory effects on cell proliferation.

[Follow-up results of brace treatment of adolescent idiopathic scoliosis]

Assessment of brace treatment for idiopathic scoliosis should be based on long-term follow-up results compared with those in untreated cases. Such comparison, however, is extremely difficult from an ethical standpoint. Therefore, we conducted a comparable follow-up study on three groups of patients divided according to how well the brace had been worn during the period of treatment. Two hundred and twenty-six adolescent idiopathic cases in which brace treatment had been initiated before skeletal maturity were studied, 170 of which were followed up after the termination of the treatment. In 131 single curve cases, those who had worn the brace well showed significantly less progression than those who had worn it poorly, while 38 double curve cases failed to show significant difference between the two groups. Approximately two thirds of the cases demonstrated no major progression whether the brace had been worn well or not. Development of a method to select cases based on prediction of curve progression is an important project in the near future.

[Epidemiologic investigation of carcinoma of the esophagus and gastric cardia carcinoma in Nanao County, Guangdong province]

Nanao county, Guangdong province is a high incidence area of carcinoma of esophagus and gastric cardia carcinoma. By retrospective investigation of data in the past 14 years (1970 to 1983), the annual average crude mortality of carcinoma of esophagus and gastric cardia carcinoma was found to be 88.65/100,000, the age adjusted mortality of Chinese population was 82.91/100,000 and that of the world population was 113.09/100,000. The mortality of the male was 100.65/100,000 and of the female was 67.24/100,000 with the ratio of 1.38:1. As regards the relationship between the age and mortality, the highest rate occurs from 50 to 74. A higher mortality was also observed in the population engaged in salt production and fishing. The mortality was higher in the lower elevation areas than in the elevated regions.

Protein kinase C phosphorylation at Thr 654 of the unoccupied EGF receptor and EGF binding regulate functional receptor loss by independent mechanisms

To test the functional consequence of phosphorylation of the EGF receptor at Thr 654 by protein kinase C, the normal Thr 654 human EGF receptor cDNA or a mutant encoding an Ala 654 were expressed in heterologous cells. In cell lines expressing both the Thr 654 and Ala 654 receptors, functional cell-surface Thr 654 receptors were reduced or were totally lost, but were not degraded, following activation of protein kinase C by phorbol esters (TPA), whereas Ala 654 receptors were unaffected. These data suggest that protein kinase C regulates ligand-independent receptor binding and internalization via phosphorylation of Thr 654 of the EGF holoreceptor. Because EGF induces internalization and degradation of the Ala 654 EGF receptor, at least two independent mechanisms can serve to signal loss of functional EGF receptors.