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H Rode

Publications and source records attributed to H Rode.

At least 37 records · Page 2Linked to original sources

An allergenic polypeptide representing a variable region of hsp 70 cloned from a cDNA library of Cladosporium herbarum.

BACKGROUND: Extracts of Cladosporium herbarum, a major source of fungal aeroallergens, exhibit a complex profile of IgE-binding proteins. Yields of conventionally purified allergens from this mold have been insufficient to permit further molecular analyses. OBJECTIVE: To enhance and simplify the purification of allergens from C. herbarum, we have sought to use recombinant DNA techniques to clone, identify and bacterially express immunoselected C. herbarum allergens. METHODS: We constructed a cDNA library in lambda ZAP II using mRNA isolated from C. herbarum. From this library, phage clones encoding a new allergen were immunoselected using pooled human atopic IgE. The cloned cDNA was excised from the phage vector as a recombinant pBluescript II SK-phagemid and sequenced. Expression of the recombinant allergen was carried out in E. coli XL1-blue transformants of the phagemid. Bacterial lysates from cells induced to express the cloned allergen were immunoblotted and probed with individual human atopic IgEs. RESULTS: The cDNA clone encodes a 278 amino acid polypeptide homologous to the C-terminal portion of 70 kDa heat shock protein (hsp 70). The polypeptide possesses features common to other hsps 70, i.e. a similar hydropathic profile and a variable C-terminal region with conserved sequence at the very C-terminus. Binding of the recombinant peptide to IgE from 38% of atopic sera or plasma from individuals allergic to C. herbarum was demonstrated. CONCLUSION: These results indicate that amino acid substitutions are relatively conserved even in the variable C-terminal regions of hsp 70 species. Thus, this study should draw attention to the possibility of induction of anaphylactic responses in a sensitized individual when hsp 70 from any pathogenic species is administered for vaccination.

Allergens

Isolation and expression of a cDNA clone encoding an Alternaria alternata Alt a 1 subunit.

Alternaria alternata is recognized as an important source of fungal aeroallergens. Alt a 1, the major allergen of this mold, is a dimer of disulfide-linked subunits that migrate in SDS-PAGE under reducing conditions at apparent M(r)s of 14,500 and 16,000. IgE antibodies to this protein are present in the sera of >90% of A. alternata-sensitive individuals. Previous studies from this laboratory showed that the N-termini twenty amino acids of the purified subunits are nearly identical. We now report the isolation of clones from an A. alternata (strain 34-016) cDNA library constructed in lambda(gt)11, using rabbit IgG antiserum against partially purified Alt a 1. One of nineteen clones selected from screens totalling 305,000 pfu (rb51) was sequenced, and determined to harbor an insert of 660 bp. An in-frame open reading frame within the cloned insert encodes a peptide of M(r) 16,960 that bears no significant homology to known allergens or proteins. The size of the rb51 transcript was determined to be approximately 0.7 kb by Northern analysis of A. alternata total RNA. The largely hydrophobic N-terminal region of the peptide contains an alpha-helical domain and other features characteristic of membrane targeting or secretory signals. The peptide sequence downstream of this region matches previously sequenced Alt a 1 N-terminal from two independent sources at 17 of 20, and 24 of 26 positions. Recombinant Alt a 1 expressed as a secreted protein in Pichia pastoris exists as a dimer in conditioned medium, as shown by immunoblotting under nonreducing conditions. Recombinant Alt a 1, like the natural allergen in A. alternata extracts, is also reactive with serum IgE from A. alternata-sensitive individuals.

Allergens

A cDNA clone coding for a novel allergen, Cla h III, of Cladosporium herbarum identified as a ribosomal P2 protein.

Mold allergens represent a major cause of atopic disorders. Progress in the molecular characterization of allergens has been hampered by batch-to-batch variation and poor yields in mold extracts. In the present study, we established a cDNA library in lambda ZAP II by using mRNA isolated from a major allergen-producing mold, Cladosporium herbarum. From this library, a novel allergen has been cloned and sequenced. The clone encodes a full length protein of 111 amino acids with a molecular mass of 11.1 kDa and pI of 3.94. By using sequence homology analysis, the allergen was found to belong to the ribosomal P2 protein family. Approximately 60% peptide sequence homology was found between the cloned protein and other known fungal ribosomal P2 proteins. In addition to conserved C-terminal sequences and serine blocks for phosphorylation in all eukaryotic ribosomal P2 proteins, this protein also contains a potential N-glycosylation site at position 15-17. Northern blots demonstrated that mRNA molecules of this gene are present even at late stages of culture. The gene was expressed in Escherichia coli by using the pMAL-2c system, and murine antisera against the recombinant allergen (rCh2.1) were generated. The antisera revealed that the native allergen corresponding to rCh2.1 was present in extracts prepared by grinding mycelia under liquid nitrogen in the presence of protease inhibitors, but absent in extracts prepared by conventional methods. This result indicates the usefulness of recombinant allergens in characterization and standardization of mold allergenic extracts.

Allergens

Transposition of the antropylorus for anal incontinence--an experimental model in the pig.

An experimental model in the pig rendered incontinent of feces was developed to assess the sphincteric activity of the transposed antropylorus. In the control group, normal defecation was studied clinically, radiologically, and manometrically. Nineteen 7- to 10-week-old pigs were rendered incontinent by resection of 20 cm of colon and rectum to below the dentate line. The antropylorus was prepared on its own blood supply and transposed to the anus, initially with a colostomy, which was closed 15 to 21 days later. Clinically these pigs passed semisolid stool in a piecemeal fashion. Contrast defecography showed hold-up at the pylorus, reflux of contrast into the colon, with pyloric contraction independent of antral stimulation. Manometry showed pyloric contraction with rise in antral pressure and independence. The authors conclude that transposition of an antropyloric segment to the anus provides a sphincter-like mechanism and could have application in fecal incontinence.

Animals

A formula to calculate blood cross-match requirements for early burn surgery in children.

Excessive bleeding from the burn site accompanies burn surgery, and blood transfusions are therefore an essential and expensive ingredient. A formula, based on the total surface area to be involved in surgery (i.e. burn plus donor area) and the patient's total blood volume, has been in use in our hospital for calculating blood cross-match volumes, but has not been scientifically evaluated. Prospectively the predicted blood loss, based on the formula in 111 consecutive paediatric burns undergoing surgery, was compared with the actual blood loss as measured using a gravimetric method. Provided that an accurate surface area to be involved in surgery is interposed into the formula, there was a statistically highly significant correlation between the predicted and actual blood loss. Invoking this simple formula may help in decreasing unnecessary cross-matching, and discarding, of blood products.

Blood Grouping and Crossmatching

Surgical repair in children with the Budd-Chiari syndrome.

Membranous obstruction of the inferior vena cava at the level of the diaphragm is a rare cause of Budd-Chiari syndrome in children. Medical therapy usually fails. Surgical intervention aims at reestablishing patency of the inferior vena cava and hepatic venous outflow to the right atrium. We report on the management of this condition in 19 children of whom 7 were treated surgically. Indications for operation were persistent ascites, deteriorating liver function, and hepatic and inferior vena caval obstruction without significant collateral circulation. Three pathologic types were identified by ultrasonography and cavography and were confirmed at operation. These were type I (4 cases), with a thin membrane occluding the inferior vena cava at the level of the diaphragm; type II (12 cases), with segmental fibrotic obstruction of the inferior vena cava with variable involvement of hepatic veins; and type III (3 cases), with complete absence or nonvisualization of the inferior vena cava. All procedures were done with an extended midline sternotomy incision, cardiopulmonary bypass, core cooling to 16 degrees to 20 degrees C, and periods of circulatory arrest. Type I lesions necessitated membranectomy; type II lesions necessitated transcaval resection of the occluded confluence of the inferior vena cava and the hepatic vein with repair of the defect with an autogenous pericardial patch. One type II lesion, in addition, called for use of a 14 cm polytetrafluoroethylene tube graft to restore inferior vena caval flow. After the operation, marked clinical improvement was observed with an immediate reduction in liver and spleen size and resolution of ascites. Repeat cavography 10 to 30 days after the operation revealed complete patency in four cases and residual stenosis, which required transiliac balloon angioplasty to normalize the inferior vena cava/right atrial pressure gradient, in 3 cases. Thus eventual relief of hepatic venous outflow obstruction and inferior vena caval flow was restored in all cases. We advocate transcardiac membranectomy and pericardial patch grafting for symptomatic and deteriorating membranous obstruction of the inferior vena cava in children.

Budd-Chiari Syndrome

N-terminus of a major allergen, Alt a I, of Alternaria alternata defined to be an epitope.

A 20mer peptide representing the N-terminus of a major allergen, Alt a I, of Alternaria alternata was synthesized and examined for its antibody binding and antibody induction activities. Alt a I peptide-BSA conjugate reacted with both human IgE and rabbit anti-Alt a I IgG in ELISA, albeit the binding of the peptide to IgE was relatively weak. Control conjugate showed no antibody binding. These results indicated that the N-terminus of Alt a I is an antibody binding site. Moreover, peptide-KLH conjugate and nonconjugated peptide induced both IgG and IgE antibodies in Balb/c mice that recognized both native Alt a I allergen and peptide-BSA conjugate. Since the free peptide was able to induce antibodies in vivo, the peptide may also possess a T cell epitope.

Allergens

Yersinia pseudotuberculosis affecting the appendix.

Yersinia pseudotuberculosis is an uncommon cause of abdominal pain. It has a much lower incidence than Yersinia enterocolitica, and most reports have emanated from Europe or North America. This report is about a patient with Yersiniosis affecting the appendix alone, in contrast to the usual picture of mesenteric adenitis or septicemia associated with this organism.

Appendix

Potential danger of 'trial of life' approach to congenital diaphragmatic hernia.

This is the report of a newborn girl who was treated by "trial of life" before surgical repair of her left-sided diaphragmatic hernia. Surgery was performed 60 hours after birth, at which time she was found to have an organo-axial volvulus of the stomach. Her postoperative course was complicated by a jejunal perforation on the fourth postoperative day, necessitating another laparotomy.

Combined Modality Therapy

Respiratory distress secondary to scalds in children.

Respiratory distress secondary to scalds in children is rare. We report 13 children (six girls and seven boys) with a mean age of 19 months who sustained this injury, who were admitted to a major referral hospital during a 5.5-year period. Associated scalds usually to the face were always present and the mean total burn surface area (TBSA) was 14.4 per cent (range 3-30 per cent). Stridor was the most common presenting symptom with a variable time of onset. Bronchoscopy was performed in 11 children and in nine the injury was confined to the supraglottic area. Five children were treated with epinephrine nebulization and the symptoms resolved in 3-4 days, one child had a prophylactic tracheostomy. Seven children required intubation and ventilation. Three children died, two of whom sustained burns to both the upper and lower respiratory tract. Respiratory distress secondary to scalds may not be recognized or the progressive nature of the injury not appreciated. In three-quarters of our patients the injury was confined mainly to above the glottis. Children with inspiratory stridor can be managed with epinephrine nebulization but more marked respiratory distress requires intubation and ventilation. Mortality was due to direct thermal injury to the respiratory tract and secondary bronchopneumonia.

Burns

Primus stove burns in Cape Town: a costly but preventable injury.

The management and outcome was evaluated in 33 patients during an 18-month period, who sustained burns as a result of working with a primus stove. There were 17 females and 16 males with an average age of 32.5 years. Twenty-nine patients were black skinned and four were coloured skinned. The average burn surface area was 16.8 per cent and the burns were deep dermal in all; 48 per cent of patients also had areas of full thickness skin loss. Twenty-seven patients were burned in more than one anatomical area. Patients spent an average of 24 days in the burns unit and all patients required tangential excision and skin grafting at least once. The average number of units of blood required was four. Only one patient died. Primus stove burns occurred in people of poor social circumstances. Primus stove burns place a heavy burden on the economic resources available. Prevention is the key to management.

Accidents

Trans-axillary transpleural sympathectomy for Palmar hyperhidrosis in children--a 3 to 7 year follow-up of 9 cases.

Primary palmar hyperhidrosis can be a most unpleasant and distressing affliction. When normal daily activities, viz. writing, schoolwork, are interfered with and other treatments have failed, surgery is indicated. Between 1983-1987 9 children (6 F, 3 M), mean age 10.2 years (range 5-14 years) underwent bilateral transaxillary sympathectomy, 4 simultaneous and 5 1-4 weeks apart. On 14 sides a standard excision of dorsal ganglia (DG) 2, 3, and 4 was performed. The technique of lateral displacement of the sympathetic chain after transection distal to DG 4 and division of preganglionic fibres of DG 4, 3 and 2 was used on 5 sides. In addition to clinical evaluation a pilocarpine stimulation test was performed on the palms of the hands before and at follow-up 3-7 years after surgery. 17/18 hands appeared sympathectomised at early follow-up. One inadequate result required reoperation. Other complications included 2 Horner's syndromes--1 transient and 1 mild but permanent; 3 temporary intercostobrachial paraesthesias, 2 mild late recurrences of sweating and 2 compensatory increases in sweating. In 14 palms where sweat volume was measured before and 3-7 years after surgery there was a mean decrease in sweat of 84% (mg), those sweating the most prior to surgery having the best response. In 2 further palms insufficient sweat was obtained for testing. All but 1 considered the procedure worthwhile. Transaxillary transpleural sympathectomy is a safe, effective, and cosmetically acceptable operation to control symptoms of excessive palmar sweating.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Two-dimensional immunoblot analysis of allergens of Cladosporium herbarum.

In the present study, allergens of Cladosporium herbarum were analysed by SDS-PAGE, two-dimensional gel electrophoresis and immunoblot. The SDS-PAGE under reduced conditions followed by western blotting analysis revealed 10 human IgE-binding components with molecular masses ranging from 15 to 143 kDa. Within the same molecular mass range, five components were detected under non-reduced conditions. Examination of the specificities of 10 individual sera revealed that two patients were sensitive to almost all the allergens, whereas the majority reacted with only some components. Two-dimensional immunoblot was employed to further analyse the allergens in the extract. A silver-stain of the two-dimensional gel revealed that there were more than 30 different protein components visible in the extract. Immunoblot of the proteins separated under denatured conditions disclosed that 17 spots were reactive with human atopic sera.

Allergens

Splenic injury.

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Adult

Ambulatory paediatric surgery. The development of a day-care surgical centre.

Ambulatory surgery has become an important component in the provision of surgical care. In 1987 a day-case surgical unit was established at Red Cross War Memorial Children's Hospital, Cape Town. Experience over a 6-year period (1987-1992) is reviewed in relation to the nature and total number of surgical procedures, pre-operative preparation, daily utilisation of the facility, postoperative care and complications. During this period 16,538 patients (mean age 3 years) were operated on in the unit. Nine surgical disciplines participated. Pre-operative assessment and preparation reduced the rate of cancellations on the day of surgery to less than 6%, with a 90% effective use of schedules operating time. Scarce nursing resources were also maximally utilised. Most procedures took less than 30 minutes and only 0.8% exceeded 1 hour. The average ward stay was 6 hours. No major complications were encountered and acceptance by patients and parents was excellent. Only 16 children who were not scheduled to do so needed to stay in hospital overnight. Recommendations to establish and improve day-stay surgical services are presented. It is concluded that a practical, efficient service can be established and that the authorities should be encouraged to expand appropriate facilities.

Ambulatory Surgical Procedures

Clones of T cells discriminate between native and deglycosylated forms of MHC class II antigen in allostimulation.

The aim of this study was to clarify the role of the oligosaccharide side chains of MHC Class II antigens in allostimulation. The approach was to cleave the oligosaccharides from protein by subjecting plasma membranes (PM) of the Daudi cell line to chemical deglycosylation yielding deglycosylated (dgl) proteins and a supernatant fraction containing plasma membrane oligosaccharides (dgl sup). MHC Class II antigens affinity purified from the native and the dgl PM were inserted into the plasma membrane of peripheral blood leukocytes (PBL) used as stimulators in a mixed leukocyte reaction (MLR). Cells used as stimulators and as responders were from the same donor. Both native and to a lesser extent the dgl antigen could elicit a proliferative as well as a cytolytic (CML) response. A comparable reduction in the CML reaction was also obtained when native antigen was used to elicit effector cells, but the target was stripped of N-linked oligosaccharides by pretreatment with tunicamycin (TM). Five clones of responding cells raised against the native antigen were studied. Two gave proliferative reactions of equal magnitude to native and to dgl antigen alike, while three responded only to the native form. These three clones did not lyse TM-treated target cells. Inhibition experiments of CML were performed with either the dgl sup containing Daudi PM oligosaccharides or with an anti MHC-Class II MoAb. CML reactivity of the three clones which responded to native antigen was blocked by the dgl sup but not by the anti-MHC antibody. Conversely, the reaction of the two clones reactive to both forms of antigen was only inhibited by the anti-MHC antibody using intact or TM-treated targets. Accordingly, in terms of the latter set of clones oligosaccharide side chains of MHC may not be required for allostimulation. Data obtained with the set of three clones suggest that oligosaccharides could act as target of cytotoxic T cells.

Cell Line

Bowel stomas in infants and children. A 5-year audit of 203 patients.

A 5-year audit of the formation, management and closure of small-bowel stomas and colostomies at Red Cross War Memorial Children's Hospital, Cape Town, is described. Of the 203 patients, 128 (63%) required the stroma in the neonatal period. Anorectal malformations (80), Hirschsprung's disease (65), necrotising enterocolitis (33), trauma (11) and neoplasm (5) comprised most of the indications. One hundred and thirty large-bowel stomas were sited in the proximal sigmoid and 37 in the transverse colon, all but 11 being divided with each end brought out through a short muscle cutting incision or through the laparotomy wound. Thirty-six ileostomies were performed and in 30 of these the stoma was sited in the wound. Complications, which included necrosis, bleeding, prolapse and wound sepsis, occurred in 31%. The colostomies sited in the transverse colon had the highest incidence of prolapse (38%). Neonatal stomas brought out in the wound had an acceptably low incidence of complications. Most stomas were temporary in nature. One hundred and eighty-eight were closed, all with excision and end-to-end intraperitoneal anastomosis. There was a 4% incidence of complications (5 would sepsis, 2 leaks, 1 stenosis). The formation, management and closure of bowel stomas represents a considerable section of the work of the paediatric surgeon. Correct meticulous technique is essential in keeping complications to a minimum.

Colostomy