New device for biofragmentable anastomotic ring in low anterior resection

PURPOSE

The biofragmentable anastomotic ring (BAR) is now accepted as an alternative anastomotic method to handsewn and stapled anastomosis in colonic surgery. However, for a short rectal stump in a narrow pelvis, it is rather difficult to use the BAR in a low anterior resection.

METHOD

To overcome the difficulty, we designed and used a BAR-adapter to facilitate biofragmentable ring anastomosis following low anterior resection in eight patients with rectal cancers.

RESULTS

There was no case in our series having received conversion to other methods. There was no significant complication associated with this technique.

CONCLUSION

With the BAR-adapter, the applicability of the BAR can be greatly expanded in colorectal anastomosis following low anterior resection.

The mechanism of V(D)J recombination: site-specificity, reaction fidelity and immunologic diversity

Site-specific recombination reactions in higher eukaryotes are uncommon, perhaps because of the potential genomic instability that they may create. We focus this review on the issues of site-specificity, reaction fidelity and immunologic diversity in the V(D)J recombination reaction.

Identification of a seven transmembrane helix receptor for corticotropin-releasing factor and sauvagine in mammalian brain

We have identified and characterized cDNAs encoding a novel receptor that is a member of a distinct class of seven transmembrane helix, Gs-coupled receptors. This receptor mediates ligand-dependent stimulation of intracellular cAMP levels in response to physiologic concentrations of corticotropin-releasing factor (CRF) and to the related frog skin peptide, sauvagine. The pattern of CRF receptor mRNA expression in the brain, pituitary gland, and other organs corresponds precisely to that predicted for the classic CRF receptor, suggesting that this receptor serves to mediate the known biological effects of CRF on behavior, stress, and homeostasis. Alternative splicing events generate a second, relatively abundant gene product expressed in a distinct ontogenic pattern. These findings serve to identify the receptor for an important neuropeptide.

Ligand-induced internalization of the epidermal growth factor receptor is mediated by multiple endocytic codes analogous to the tyrosine motif found in constitutively internalized receptors

Ligand-induced internalization of epidermal growth factor (EGF) receptors via a high affinity saturable pathway requires sequences located in the carboxyl terminus distal to the tyrosine kinase domain. Three regions were found to contain endocytic motifs as defined by their ability to restore internalization function to EGF receptors truncated at the distal border of the kinase domain at residue 958. Deletional analysis identified the sequence 996QQGFF as essential for function of the region encompassing residues 993-1022. QQGFF and the deduced sequence of the region encompassing residues 973-991 (973FYRAL) could effectively replace the endogenous endocytic code of the transferrin receptor (YTRF). FYRAL and YTRF were less active than QQGFF when substituted into region 993-1022 of the EGF receptor, but a synthetic sequence (NNAYF), predicted to have structural features of a tight turn, effectively replaced QQGFF for EGF receptor internalization. Whereas EGF receptor sequences functioned effectively in the transferrin receptor, function of these sequences in the EGF receptor was strictly dependent on intrinsic tyrosine kinase activity as demonstrated kinetically and by immunofluorescence using semithin cryosections. Ligand-dependent endocytosis and down-regulation of the EGF receptor thus require multiple sequence motifs that are exchangeable between ligand-dependent and -independent receptors, but that require intrinsic tyrosine kinase activity for function in the context of the EGF receptor.

Xe-133 muscle blood flow in polymyositis and dermatomyositis

The histologic picture of polymyositis or dermatomyositis is characterized by muscle fiber degeneration, which is assumed to be caused by a circulatory abnormality. To verify this assumption, we measured the muscle blood flow in patients with polymyositis (or dermatomyositis) and in normal subjects using the inert gas Xe-133. Sixteen patients and 30 age-matched normal volunteers were studied. Muscle blood flow was measured with Xe-133 dissolved in isotonic saline as described by Lassen et al. (1964) and Pozderac et al. (1975). Data were acquired in the frame mode after intramuscular injection (anterior tibial muscle) of 0.3 mCi of Xe-133 in 0.2ml of saline for 20 min. A computer routine was used to calculate the clearance half time (T 1/2) in min and flow rate (Q) in ml/100 gm tissue/min. The student's t test was used to test statistical significance. Our preliminary results suggest: 1. The muscle blood flow in patients with polymyositis and dermatomyositis was significantly lower than the corresponding normal control levels. 2. This findings may be due to decreased in muscle capillary 3. Further studies are warranted to obtain a conclusive understanding of the pathogenesis of polymyositis and dermatomyositis.

Solid phase radionuclide esophageal motility in polymyositis and dermatomyositis

Polymyositis (PM) and dermatomyositis (DM) may be associated with motor dysfunction of the entire gastrointestinal tract. Abnormal esophageal motor function is a well-recognized complication of these diseases. In this study, we used a solid phase esophageal study to evaluate the motor function in patients with PM or DM. Twenty-three patients and 36 age-matched normal volunteers were studied. Each subject was placed in a supine position above a gamma camera linked to a computer and was given a 4-ml bolus of solid gelatin containing 1 mCi of Tc-99m phytate. Data were acquired in the list mode. A computer method modified from Kelim and Wald and Russell et al. was used to calculate the following: A) total mean transit time (MTT); B) residual fraction after the first swallow (RF); and C) retrograde index (RI). All values are presented as mean +/- standard deviation (SD). The Student's t-test was used to test statistical significance. Our preliminary results suggest: 1) delayed esophageal emptying is common (17/23) in PM/DM, indicating frequent malfunction of the smooth muscle of the upper gastrointestinal tract in PM/DM and 2) measurement of esophageal motility may monitor disease activity in PM/DM.

Contribution of platelet microparticle formation and granule secretion to the transmembrane migration of phosphatidylserine

Activation of human platelets by complement proteins, C5b-9, thrombin plus collagen, or a Ca2+ ionophore results in surface exposure of phosphatidylserine (PS), accompanied by the expression of membrane catalytic activity for the tenase (VIIaIXa) and prothrombinase (VaXa) coagulation enzyme complexes. The mechanism underlying this surface exposure of PS upon platelet activation remains unresolved. Using fluorescent derivatives of PS (NBD-PS), we have investigated how the transmembrane migration of PS is related to microvesiculation of the platelet plasma membrane and to fusion of storage granules with the plasma membrane. Gel-filtered platelets were incubated with NBD-PS, allowing 90 +/- 10% of the incorporated NBD-PS to accumulate into the inner leaflet of the plasma membrane. Migration of NBD-PS from the inner leaflet to the plasma membrane surface was monitored by time-based flow cytometry, and correlated with the appearance of platelet microparticles and alpha-granule secretion. Platelet activation by C5b-9 or the Ca2+ ionophore, A23187, increased surface exposure of NBD-PS, due to acceleration of the apparent rate of migration from inner to outer plasma membrane leaflets. The onset of this accelerated migration of NBD-PS to the surface coincided with the onset of plasma membrane vesiculation, and the NBD-PS that partitioned into the membrane of the shed microparticle was also rapidly exposed to the surface (t1/2 < 2 min). In addition to a temporal correlation, microparticle formation and the surface exposure of inner leaflet NBD-PS showed a similar requirement for Ca2+. These results demonstrate that agonist-induced microvesiculation of the platelet plasma membrane is accompanied by accelerated migration of a PS analogue from the inner leaflet to the surface of the shed microparticle membrane, suggesting the mechanism by which induction of platelet microparticle formation exposes catalytic surface for tenase and prothrombinase assembly.

Pit-1-dependent expression of the receptor for growth hormone releasing factor mediates pituitary cell growth

In Snell (dw) and Jackson (dwJ) dwarf mice, mutations in the gene encoding Pit-1, a tissue-specific POU-domain transcription factor, lead to the absence of somatotroph, lactotroph and thyrotroph cells. Pre-somatotroph proliferation is stimulated by increased intracellular levels of cyclic AMP, normally induced by growth hormone releasing factor (GRF; refs 7-17). Here we report the cloning of mouse and rat complementary DNAs encoding a new member of the seven-transmembrane-helix, G-protein-coupled receptor family restricted to the pituitary gland, which mediates increases in intracellular cAMP and cAMP-dependent gene transcription in response to GRF. The receptor is expressed in a spatial and temporal pattern corresponding precisely to growth hormone gene expression, and neither is expressed in dw/dw mice. The pituitary hypoplasia in these mice thus appears to be due, at least in part, to the absence of GRF receptor, which is in turn due to the absence of functional Pit-1.

Light and electron microscopic observations on the synovitis of ankylosing spondylitis

Light microscopic studies on synovium obtained from seven knees and three hips of patients with ankylosing spondylitis and peripheral arthritis showed surface fibrin, proliferation of synovial lining cells, moderate infiltration with lymphocytes, and sometimes striking numbers of plasma cells. There was some vascular congestion and obliteration, occasional bone and cartilage debris, and a tendency toward increased fibrous tissue. Although the intensity of some findings varies from those in rheumatoid arthritis, there were no consistent distinguishing features. Electron microscopy of eight synovial tissue specimens showed increased type B or synthetic lining cells. Structures that could possibly have been organisms were seen among synovial cells in two patients. Immune complex-like deposits were not seen in vessel walls, although there were other vascular alterations. Synovial fluid studies showed 2,200 to 16,500 white blood cells/mm3 (mean, 8,236), 29% to 93% polymorphonuclear leukocytes (mean, 66%), and 0.5 to 32% lymphocytes (mean, 18%). The presence of at least some activated lymphocytes (lymphoblasts) in seven of nine patients in addition to the above findings in synovium suggest an immunological component to the driven process. No more than 32% lymphocytes was found in any synovial fluid despite the use of nonsteroidal antiinflammatory drugs. Thus no support for synovial fluid lymphocytosis, such as has been described in rheumatoid arthritis patients treated with nonsteroidal antiinflammatory drugs alone, is provided.

A site of tyrosine phosphorylation in the C terminus of the epidermal growth factor receptor is required to activate phospholipase C

Cells expressing mutant epidermal growth factor (EGF) receptors have been used to study mechanisms through which EGF increases phospholipase C (PLC) activity. C-terminal truncation mutant EGF receptors are markedly impaired in their ability to increase inositol phosphate formation compared with wild-type EGF receptors. Mutation of the single tyrosine self-phosphorylation site at residue 992 to phenylalanine in an EGF receptor truncated at residue 1000 abolished the ability of EGF to increase inositol phosphate formation. C-terminal deletion mutant receptors that are impaired in their ability to increase inositol phosphate formation effectively phosphorylate PLC-gamma at the same tyrosine residues as do wild-type EGF receptors. EGF enhances PLC-gamma association with wild-type EGF receptors but not with mutant receptors lacking sites of tyrosine phosphorylation. These results indicate that formation of a complex between self-phosphorylated EGF receptors and PLC-gamma is necessary for enzyme activation in vivo. We propose that both binding of PLC-gamma to activated EGF receptors and tyrosine phosphorylation of the enzyme are necessary to elicit biological responses. Kinase-active EGF receptors lacking sites of tyrosine phosphorylation are unable to signal increased inositol phosphate formation and increases in cytosolic Ca2+ concentration.

Ligand-induced internalization and increased cell calcium are mediated via distinct structural elements in the carboxyl terminus of the epidermal growth factor receptor

Signals that can mediate ligand-induced receptor internalization and calcium regulation are present in a 48-amino acid "calcium-internalization" domain in the C' terminus of the epidermal growth factor (EGF) receptor. The basis of calcium and internalization regulation signalled by this 48-amino acid sequence was analyzed using deletion and substitution mutant receptors. Cells expressing truncated receptors containing either the NH2- or COOH-terminal portion of the 48-residue domain displayed high affinity EGF-dependent endocytosis and receptor down-regulation. These endocytosis-competent EGF receptor mutants that lacked any autophosphorylation site were unable to increase the concentration of intracellular calcium. To investigate the role of self-phosphorylation in EGF-induced calcium mobilization, phenylalanine was substituted for the single autophosphorylated tyrosine residue in this region of an internalization-competent truncated receptor. The receptor-mediated calcium response was abolished, while ligand-dependent receptor internalization was unimpaired. These results demonstrate that EGF-dependent receptor endocytosis and calcium mobilization are separate events. Tyrosine self-phosphorylation is required for increased [Ca2+]i, while structural features distinct from autophosphorylation are required for receptor internalization.

Autonomic hyperreflexia in spinal cord injury patient during percutaneous nephrolithotomy for renal stone: a case report

Autonomic hyperreflexia or autonomic dysreflexia is a syndrome seen in approximately 85% of all quadriplegic patients and constitutes the only medical emergency related to spinal cord injury. We report on a paraplegic patient with a C5 to C7 spinal cord injury who suffered autonomic hyperreflexia during percutaneous nephrolithotomy for a right renal stone. The reflex-induced hypertension subsided with termination of the operation, and administration of an alpha and beta-adrenergic blocking agent (labelatol hydrochloride). The stone was removed successfully by pyelolithotomy with the patient under general anesthesia 4 days later.

Primary biliary cirrhosis and scleroderma complicated by Barrett's oesophagus. A case report

Oesophageal problems are common in patients with scleroderma, but the association of primary biliary cirrhosis and scleroderma is uncommon. A Barrett's oesophagus identified in a patient with primary biliary cirrhosis and scleroderma is described. The Barrett's oesophagus was probably a complication of scleroderma and resulted from low lower-oesophageal sphincter pressure and severe gastro-oesophageal reflux.

Stomach and duodenal alcohol and aldehyde dehydrogenase isozymes in Chinese

Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) isozyme phenotypes were determined in surgical and endoscopic biopsies of the stomach and duodenum by agarose isoelectric focusing. gamma-ADH was found to be the predominant form in the mucosal layer whereas beta-ADH was predominant in the muscular layer. Low-Km ALDH1 and ALDH2 were found in the stomach and duodenum. High-Km ALDH3 isozymes occurred only in the stomach but not in the duodenum. The isozyme patterns of gastric mucosal ALDH2 and ALDH3 remained unchanged in the fundus, corpus, and antrum. The stomach ALDH3 isozymes exhibited a Km value for acetaldehyde of 75 mM, and an optimum for acetaldehyde oxidation at pH 8.5. Since the Km value was high, ALDH3 contributed very little, if any, to gastric ethanol metabolism. The activities of ALDH in the gastric mucosa deficient in ALDH2 were 60-70% of that of the ALDH2-active phenotypes. These results indicate that Chinese lacking ALDH2 activity may have a lower acetaldehyde oxidation rate in the stomach during alcohol consumption.

Incidental adenocarcinoma of the prostate: a retrospective analysis

Between January 1980 and June 1990, 5875 patients underwent either TURP (5,529) or open prostatectomy (346) for the management of benign prostatic hyperplasia. Incidental carcinoma was identified in 53 patients (0.9%) - 49 in the TURP group and 4 in the open prostatectomy group. The overall incidence of stage A prostate carcinoma during the same period was 13.1% (53/406). Of those 50 regularly followed patients, only 6 (12.0%) underwent subsequent radical prostatectomy with pelvic lymphadenectomy, and residual tumors were identified in 4 patients (66.7%). The progression rate was 33.3% (3/9) in high-grade tumors (Gleason's score greater than 6) and 7.7% (2/26) in low-grade tumors (Gleason's score less than 5). In those 50 patients, 41 (82.0%) presented no evidence of disease and 9 (18.0%) stayed alive with progression. The mean length of follow-up was 34 months (range: 2-108 months). Our study demonstrates that the outcome of incidental carcinoma of the prostate is good. However, the residual tumor rate still remains high at 66.7%. Radical prostatectomy is recommended in young patients or in patients with high grade tumor.

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.

[Experience in using modified HM-3 Dornier lithotripter to treat urinary tract stones]

Low pressure generator has been developed mainly to reduce pain and kidney injury while at the same time maintain an equally effective stone-free rate. Our experience in using Modified HM-3 Dornier lithotripter to treat urinary tract stones has given an average of stone-free rate (58.88%) quite similar to what the conventional one can give. Compared with the conventional intervention, the modified one might increase by 52.07% (2281 vs 1500 pulses) in the average frequency of shock wave and by 26.52% (38.40 vs 30.35 minutes) in average operation time. However, low pressure may contribute to less complications and overall smoother procedure under oral analgesic use.

Identification and expression of a human cytomegalovirus early glycoprotein

A human cytomegalovirus early gene which possesses three temporally regulated promoters is located in the large unique component of the viral genome between 0.054 and 0.064 map units (C.-P. Chang, C.L. Malone, and M.F. Stinski, J. Virol. 63:281-290, 1989). This gene contains a major open reading frame (ORF) located 233 bases downstream of the cap site of an early unspliced RNA. The major ORF predicts a polypeptide of 17 kilodaltons (kDa) which contains a glycoproteinlike signal and anchor domains as well as potential N-glycosylation sites. Antisera were prepared against synthetic peptides derived from amino acid sequences within the major ORF. The antisera detected a viral glycoprotein of 48 kDa in infected cells and recognized the in vitro-translated 17-kDa protein early-gene product. The viral glycoprotein, designated gp48, was modified by N-linked glycans and possibly O-linked glycans. The synthesis of gp48 occurred in the absence of viral DNA replication but accumulated to the highest levels at late times after infection. Since gp48 was found in the virion, it is considered an early structural glycoprotein.

A human cytomegalovirus early gene has three inducible promoters that are regulated differentially at various times after infection

The long inverted repeat and the adjacent sequences are major early transcription sites of the human cytomegalovirus genome (M. W. Wathen and M. F. Stinski, J. Virol. 41:462-477, 1982). An early transcription unit which flanks the large terminal repeat was analyzed by RNA mapping at various times after infection. Three unspliced, overlapping RNAs were transcribed from different initiation sites and terminated at the same 3' end. Individual promoters were isolated for all three transcripts. These promoters were activated in trans by viral immediate-early (IE) regulatory proteins after either infection with virus or cotransfection with IE2 alone or IE1 plus IE2 genes. DNA sequence analysis detected TATA and CAAT boxes plus multiple-dyad symmetries in the promoter-regulatory region. Deletion analyses showed that the maximum inducible promoter activity lay in a 230-base-pair region. When in the viral genome, the three promoters were regulated differentially during the course of infection. The upstream promoter was used only at late times after infection. Possible reasons for viral RNAs with multiple 5' ends at different times after infection and the recognition of the upstream promoter at only late times after infection are discussed.

Secretion of functional antibody and Fab fragment from yeast cells

We have constructed yeast strains that secrete functional mouse-human chimeric antibody and its Fab fragment into the culture medium. For chimeric whole antibody, cDNA copies of the chimeric light-chain and heavy-chain genes of an anti-tumor antibody were inserted into vectors containing the yeast phosphoglycerate kinase promoter, invertase signal sequence, and phosphoglycerate kinase polyadenylylation signal. Simultaneous expression of these genes in yeast resulted in secretion of properly folded and assembled chimeric antibody that bound to target cancer cells. Yeast chimeric antibody exhibited antibody-dependent cellular cytotoxicity activity but not complement-dependent cytotoxicity activity. For production of Fab fragments, a truncated heavy-chain (Fd) gene was created by introducing a stop codon near the codon for the amino acid at which papain digestion occurs. Simultaneous expression of the resulting chimeric Fd and light-chain genes in yeast resulted in secretion of properly folded and assembled Fab fragment that bound to target cancer cells.

Cockroach hypersensitivity: preliminary study of allergic cockroach asthma in Taiwan

One hundred eight-two atopic patients were skin tested with cockroach antigen. Of these 182 patients, 54.9% gave positive immediate skin reaction by intracutaneous test. Among those atopic patients tested, 57.5% of patients with asthma and 50.7% of patients with allergic rhinitis were sensitive to cockroach extracts. The specific IgE antibody was determined by fluoroallergosorbent test. Of 79 cockroach-positive atopic patients, 39.2% were found to contain IgE antibodies against cockroach. No specific IgE was detected in cockroach-negative atopic and nonatopic subjects. Bronchial provocation test with cockroach antigen was performed on 15 subjects. Immediate asthmatic response was detected in six of nine cockroach-positive subjects with asthma. Two cockroach-negative subjects with asthma and four nonatopic subjects demonstrated no significant decrease in FEV1. The results indicate that cockroach induces antigen-specific IgE-mediated bronchial asthma, and cockroach is one of the major causes of allergic asthma.