Unusual clinical and histopathological presentation of facial tuberculosis

Atypical facial lupus vulgaris is described in two cases. The first case resembled sarcoidosis clinically and histologically but responded well to ATT. The second case whose clinical diagnosis of lupus vulgaris was confirmed therapeutically had an atypical histology.

Isolation and Identification of novel toxins from a new mosquitocidal isolate from Malaysia, Bacillus thuringiensis subsp. jegathesan

A new mosquitocidal Bacillus thuringiensis subsp., jegathesan, has recently been isolated from Malaysia. Parasporal crystal inclusions were purified from this strain and bioassayed against fourth-instar larvae of Culex quinquefasciatus, Aedes aegypti, Aedes togoi, Aedes albopictus, Anopheles maculatus, and Mansonia uniformis. The 50% lethal concentration of crystal inclusions for each species was 0.34, 8.08, 0.34, 17.59, 3.91, and 120 ng/ml, respectively. These values show that parasporal inclusions from this new subspecies have mosquitocidal toxicity comparable to that of inclusions isolated from B. thuringiensis subsp. israelensis. Solubilized and chymotrypsin-activated parasporal inclusions possessed low-level hemolytic activity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that the crystals were composed of polypeptides of 77, 74, 72, 68, 55, 38, 35, 27, and 23 kDa. Analysis by Western blotting (immunoblotting) with polyclonal antisera raised against toxins purified from B. thuringiensis subsp. israelensis reveals that proteins in parasporal inclusions of subsp. jegathesan are distinct, because little cross-reactivity was shown. Analysis of the plasmid content of B. thuringiensis subsp. jegathesan indicates that the genes for toxin production may be located on 105- to 120-kb plasmids. Cry- clones that have been cured of these plasmids are nontoxic. Southern blot analysis of plasmid and chromosomal DNA from subsp. jegathesan showed little or low homology to the genes coding for CryIVA, CryIVB, and CryIVD from B. thuringiensis subsp. israelensis.

Characterization of human lymphoid cell lines GM9947 and GM9948 as intra- and interlaboratory reference standards for DNA typing

The incorporation of reference DNA is crucial to the validation of any DNA typing protocol. Currently, reference DNA standards are restricted to molecular size DNA ladders and/or tumor cell line DNA. Either of these, however, presents some limitations. We have rigorously characterized two Epstein-Barr virus (EBV)-immortalized human lymphoid cell lines--GM9947 (female) and GM9948 (male)--to determine their suitability as alternative in-line standards for three widely employed allele profiling strategies. Twenty-one highly polymorphic VNTR-based allelic systems (7 RFLPs, 2 AmpFLPs, and 12 STRs) distributed over 12 chromosomes were scrutinized along with 3 gender-based discriminatory systems. The genetic stability of each locus was confirmed over a period of 225 in vitro population doublings. Allele size estimates and degree of informativeness for each of the 21 VNTR systems were compiled. The reproducibility of allele scoring by traditional RFLP analyses, using both cell lines as reference standards, was also verified by an interlaboratory validation study involving 13 analysts from two geographically distinct forensic laboratories. Taken together, our data indicate that GM9947 and GM9948 genomic DNAs could be adopted as reliable reference standards for DNA typing.

Comparison of toxin overlay and solid-phase binding assays to identify diverse CryIA(c) toxin-binding proteins in Heliothis virescens midgut

The binding proteins, or receptors, for insecticidal Bacillus thuringiensis subsp. kurstaki delta-endotoxins are located in the brush border membranes of susceptible insect midguts. The interaction of one of these toxins, CryIA(c), with proteins isolated from Heliothis virescens larval midguts was investigated. To facilitate the identification of solubilized putative toxin-binding proteins, a solid-phase binding assay was developed and compared with toxin overlay assays. The overlay assays demonstrated that a number of proteins of 170, 140, 120, 90, 75, 60, and 50 kDa bound the radiolabeled CryIA(c) toxin. Anion-exchange fractionation allowed the separation of these proteins into three toxin binding fractions, or pools. Toxin overlay assays demonstrated that although the three pools had distinct protein profiles, similar-size proteins could be detected in these three pools. However, determination of toxin affinity by using the solid-phase binding assay showed that only one of the three pools contained high-affinity binding proteins. The Kd obtained, 0.65 nM, is similar to that of the unsolubilized brush border membrane vesicles. Thus, the solid-phase binding assay in combination with the toxin overlay assay facilitates the identification and purification of high-affinity B. thuringiensis toxin-binding proteins from the insect midgut.

Cloning, functional expression, and pharmacology of a GABA transporter from Manduca sexta

Termination of synaptic transmission occurs by several mechanisms that include uptake of the neurotransmitter molecules into the presynaptic neuron by specialized membrane transport proteins. We have cloned a (DABA)-sensitive gamma-aminobutyric acid (GABA) transporter from a cDNA library from Manduca sexta embryo. The cDNA clone, MasGAT, shows high sequence homology to known mammalian GABA transporters. The transcript is about 5.5 kb with an open reading frame of 1793 bp. Injection of a 2.2-kb cRNA from this clone into Xenopus oocytes results in [3H]GABA transport. A Michaelis-Menten kinetic analysis shows that GABA transport occurs by a high-affinity and saturable process, suggesting that it is carrier-mediated. Ion substitution studies also show the transport process to be highly dependent on extracellular Na+ gradient, a finding that is consistent with properties of known mammalian neurotransmitter transporters. Although MasGAT shares certain pharmacological similarities with known mammalian GABA transporters, this transporter is pharmacologically distinct from the known mammalian GABA transporters.

Mechanism of action of Bacillus thuringiensis toxins

The selectivity of Bacillus thuringiensis toxins is determined both by the toxin structure and by factors inherent to the insect. These toxins contain distinct domains that appear to be functionally important in toxin binding to protein receptors in the midgut of susceptible insects, and the subsequent formation of a pore in the insect midgut epithelium. In this article features necessary for the insecticidal activity of these toxins are discussed. These include toxin structure, toxin processing in the insect midgut, the identification of toxin receptors in susceptible insects, and toxin pore formation in midgut cells. In addition a number of B. thuringiensis toxins act synergistically to exert their full insecticidal activity. This synergistic action is critical not only for expressing the insecticidal activity of these toxins, but could also play a role in delaying the onset of insect resistance.

The impact of interactive image guided surgery: the Bristol experience with the ISG/Elekta viewing Wand

From June 1992 to August 1994 we have accumulated a 305 case experience with the ISG Viewing Wand, the first commercially available system for interactive image guided neurosurgery. Prior to the arrival of the wand 2.5% of intracranial procedures were carried out using the Leksell G frame for image guidance. Since the arrival of the wand that percentage of procedures suitable for image guidance has increased to 10%. The wand was used for 287 supratentorial procedures, 108 craniotomies, 48 trephine exposures, 34 burr hole biopsies, 4 ventriculoscopies and 1 shunt insertion, 19 posterior fossa explorations were performed, 28 skull base procedures, including 22 transsphenoidal pituitary operations, 3 petrousectomies and 3 orbital explorations were also carried out. In addition 3 spinal cases were included in the series, 2 transoral explorations and 1 sacral laminectomy. The technique was applicable to 193 tumour cases, 14 vascular cases including 7 aneurysms and 16 epilepsy cases. Both CT (70%) and MRI (30%) scans were used for image guidance. Contour matching algorithms were used for registration throughout. Since the arrival of the wand conventional stereotaxy has been used for 26 cases, 22 stereotactic biopsies, 2 thalamotomies and 2 craniotomies (0.5% of intracranial procedures). We conclude that contour matching, interactive image guidance using a mechanical arm has replaced frame based stereotaxy in our department except for point source localisation in deep midline structures. It is a technique that has universal application to intracranial neurosurgical procedures and as such represents a major advance in image guided neurosurgery.

THE PINEAL PARENCHYMAL NEOPLASMS - A CLINICOPATHOLOGICAL STUDY OF FOUR TUMOURS

Tumours of pineocytes are rare intracranial tumours. They are suspected once the effects of compression of neighbouring structures manifest. Four pineocytic neoplasms are reported, of which one was a spinal metastasis. Clinical features and radiological appearances are described. Histopathological diagnosis was based upon cytoarchitectural patterns which are discussed. Surprisingly all four cases occurred in a period of one month.

IN VITRO COMPARATIVE ACTIVITY OF EIGHT ANTIPSEUDOMONAL AGENTS

Five hundred and thirty strains of Pseudomonas aeruginosa isolated from indoor patients were tested against three chemical groups comprising eight antibiotics. High degree of resistant strains ranging from 38.0% to 61.8% were seen against carbenicillin, piperacillin and gentamicin. However amikacin, ciprofloxacin, ceftazidime, netilmicin and norfloxacin showed comparatively better activity with resistant strains ranging from 7.8% to 22.8%. A notably higher rate of resistance was seen in urinary isolates.

Role of formalin-preserved allograft in fresh fractures with comminution

The use of bone grafting in polytrauma patients is associated with significant problems. Additional surgical time is required for the use of cancellous autografts, and there may be a significant incidence of donor site morbidity. Various types of allografts used in western countries are expensive to obtain and store, and the technical know-how required for their use may not be available in Third World countries. A series is reported in which formalin-preserved allograft (FPA) was used for the management of comminuted fractures in 22 polytrauma cases. This type of allograft is inexpensive, easy to prepare and store, and has been shown in experimental and clinical studies to be nonantigenic and sterile. The complication rate and time to union were comparable with a control series of autografted cases and previously reported series in the literature. Based on the results in this series of patients, the use of FPA is recommended for the grafting of multiple fractures, especially when other forms of allograft are not available because of technical or financial limitations.

Tuberculosis of bones and joints of the foot: an analysis of 22 cases

Skeletal tuberculosis constitutes 1% to 3% of extrapulmonary cases and involvement of foot bones is rare. Lack of awareness and a confusing clinical and radiological picture often lead to a delay in diagnosis. We reviewed 23 feet seen over a 3.5-year period. Most cases were children or young adults less than 40 years of age; isolated bony involvement was seen in 10 feet, with the calcaneus being involved in five cases. Articular involvement at presentation was seen in 13 cases and these cases had significantly higher delays in diagnosis. Twenty cases responded to antitubercular therapy alone while one case had to be operated (there was one fatal outcome). Complete resolution of sequestra was seen with antitubercular therapy alone. The results were better in cases with isolated bony involvement, while cases with joint involvement had residual sequelae in the form of stiffness or pain. Two patients were advised arthrodesis. Early diagnosis and antitubercular therapy is essential to prevent joint involvement from periarticular bony lesions; surgical intervention is rarely needed. A high index of suspicion has to be maintained in high risk groups like Asian immigrants. Concomitant extraskeletal lesions may not always be present.

Comparison of fresh autogenous with formalin preserved allogeneic bone grafts in rabbits. An experimental study

A complete circumferential gap was produced in the diaphysis of the ulna in rabbits and the radius was left intact. The gap on the right side was filled with formalin preserved allogeneic (FPA) bone graft, and fresh autogenous bone taken from the right ulna was put into the gap on the left side. The gap was left untouched in a control group. Up to 8 weeks, the rate of union was slower in the FPA grafts compared with the autogenous grafts. Maximum fluorescence was seen at 10 to 16 weeks and was the same in both groups. These results indicate that osteoinduction occurs with normal bony repair in 80% of both groups, although the onset of healing is delayed in the FPA grafts.

Sequence of a 17 kDa vacuolar H(+)-ATPase proteolipid subunit from insect midgut and Malpighian tubules

A 0.4 kb polymerase chain reaction (PCR) product obtained from cDNA made from the midgut and Malpighian tubules of fifth instar larvae of Heliothis virescens was used to screen a larval midgut and Malpighian tubules cDNA library. Four clones were obtained, one of 1.9 kb and others of 1.4 kb. The 1.9 kb clone encodes a 17.2 kDa protein which is highly homologous to other vacuolar ATPases proteolipids. Putative N-glycosylation and DCCD binding sites were observed at amino acid residues 83 and 139, respectively.

Primary bone malignancies in pregnancy. A report of four cases

Primary malignant bone tumors are rarely associated with pregnancy. Because of the rare nature of the condition, the relevant literature available is scant, providing limited information to the clinician about its management. Common management problems stem from delayed diagnosis and the limitations on the use of routine therapeutic modalities (eg, radiation and chemotherapy) during pregnancy. The cases presented include two cases of Ewing's sarcoma, one case of osteosarcoma, and one malignant fibrous histiocytoma that is thought to be multicentric in origin. Three of these tumors involved the scapula. The patients' social customs and general medical ignorance significantly affected the outcome of these cases.

Management of giant cell tumor of the tarsal bones: a report of nine cases and a review of the literature

Giant cell tumor of the tarsal bones is uncommon and therapeutic options are ill defined. We report on nine cases of giant cell tumors of the tarsal bones treated by excision of the complete bone in 6 cases, partial excision in 1 case, and curettage and bone grafting in two cases. There was no recurrence at an average 25.8-month follow-up. Function after calcanectomy was satisfactory. Excision of the talus may or may not be followed by arthrodesis, but arthrodesis is essential after excision of all the other tarsal bones except the calcaneus. We advocate aggressive surgical measures in these cases; amputation should be reserved for recurrences only. Satisfactory function may be expected after excision of tarsal bones.

Heart transplantation: operative techniques and postoperative management

Heart transplantation has become an established therapeutic option for some patients with end stage heart failure. The technique of heart transplantation involves excision of the diseased heart leaving behind cuffs of the right and left atria, pulmonary artery and aorta, which are subsequently attached to their counterparts in the procured donor heart. In most cases donor and recipient operations are carried out in two different hospitals which can be hundreds of miles apart. Careful coordination and timing of the donor and recipient operations is fundamental to keep the ischemic time (ie, the time taken to remove the donor heart, transport to the transplant center and implant in the recipient) to a minimum. Ischemic time longer than 4 hours carries a significantly higher operative mortality. Preservation of the donor heart during the period of ischemia is achieved using a potassium based cardioplegic solution which arrests the heart in diastole, and is supplemented with topical cooling to keep the myocardial temperature at 4 degrees C. Due to cardiac denervation and impaired ability to respond to high filling pressures, maintaining a fast heart rate is essential to maximize cardiac output during the early postoperative period. High pulmonary vascular resistance can occur postoperatively and can result in failure of the donor heart. This may require the use of vasodilators and mechanical right heart assistance. In addition to the use of immunosuppressive agents to prevent rejection of the donor heart, careful attention should be given to renal function and to prophylaxis against infection. The overall 30-day survival (ie, operative survival) currently exceeds 95%.

High-level cryIVD and cytA gene expression in Bacillus thuringiensis does not require the 20-kilodalton protein, and the coexpressed gene products are synergistic in their toxicity to mosquitoes

Interactions among the 20-kDa protein gene and the cytA and cryIVD genes located in a 9.4-kb HindIII fragment were studied. A series of plasmids containing a combination of these different genes was constructed by using the Escherichia coli/Bacillus thuringiensis shuttle vector pHT3101. The plasmids were then used to transform an acrystalliferous strain, cryB, derived from B. thuringiensis subsp. kurstaki. The results from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analyses suggest that although the 20-kDa protein is required for the efficient CytA protein production in E. coli, it is not required in B. thuringiensis. With or without the truncated 20-kDa protein gene, the CtyA and/or CryIVD proteins are produced and form parasporal inclusions in B. thuringiensis cells. However, more-efficient expression is obtained when a second protein, probably acting as a chaperonin, is present. In addition, the time course studies show that the CytA and CryIVD proteins are coordinately produced. Both the crude B. thuringiensis culture and purified inclusions from each recombinant B. thuringiensis strain are toxic to Culex quinquefasciatus larvae. The parasporal inclusions formed in B. thuringiensis cells are mosquitocidal, with CytA synergizing CryIVD toxicity.

In vitro and in vivo proteolysis of the Bacillus thuringiensis subsp. israelensis CryIVD protein by Culex quinquefasciatus larval midgut proteases

Proteases with trypsin-, chymotrypsin- and thermolysin-like specificity were detected in Culex quinquefasciatus larval midguts. Their activities were monitored by N-terminal amino acid sequence analysis of the Bacillus thuringiensis subsp. israelensis CryIVD toxin proteolytic fragments. These proteases are located in the larval midgut and in different fractions obtained during the preparation of brush border membrane vesicles. The activity of the midgut proteases increased with an increase in pH. Both the chymotrypsin- and thermolysin-like activities are involved in the processing of solubilized CryIVD toxin, whereas an additional trypsin-like protease is necessary for the CryIVD parasporal inclusion processing. The solubilized CryIVD toxin was first cleaved between Thr347 and Phe348 and between Phe348 and Tyr349, generating a 40-kDa N-terminal fragment and a 32.5-kDa C-terminal fragment. The C-terminal domain was resistant to further processing, with only a small amount of a 31-kDa product appearing due to the action of a thermolysin-like protease. However, the N-terminal domain was very unstable, and was further degraded to about 30 kDa. Unlike the solubilized CryIVD toxin, the processing of the CryIVD parasporal inclusion was very slow at neutral pH. Three protease-resistant products were detected at pHs higher than 9.5 with an overnight incubation at 37 degrees C. The 30- and 28.5-kDa C-terminal peptides are proteolytic products of trypsin- and chymotrypsin-like proteases, respectively; while the 28-kDa N-terminal peptide has 27 amino acids deleted from the N-terminal end by a thermolysin-like protease.

Chronically unreduced traumatic anterior dislocation of the hip: a report of four cases

Four cases of unreduced (2-11 months postinjury) anterior hip dislocation are reported. One public dislocation 2 months postinjury was treated by open reduction with a fair result. A unique case of iliac dislocation 11 months postinjury, overlooked due to an associated femoral shaft fracture, was treated by valgus/derotation osteotomy. Two obturator dislocations 7.5 and 9.5 months postinjury were treated by a subcapital osteotomy and displacement of the femoral neck into the acetabulum (modified excision arthroplasty). Both of these patients had fairly stable, painless, and mobile hips at 2.1 and 2.8 years follow-up. By our method, subsequent total hip arthroplasty remains a viable option, in contrast to the previously described method of trochanteric osteotomy, whereby the proximal femoral anatomy is distorted.

Fibular osteosynthesis for delayed type II and type III femoral neck fractures in children

Seventeen transcervical/basal femoral neck fractures in children were treated by free fibular graft and cancellous lag screw. Two cases were failures of a previous surgery, and 15 had been untreated for 3 weeks or more. Four cases had radiological evidence of avascular necrosis of the head and one of the neck preoperatively; five cases had neck resorption. At an average of 48.1 months postsurgery all fractures had united and there was only one new case of avascular necrosis. Four cases had coxa vara, and four cases had premature epiphyseal closure. There were 13 good, three fair, and one poor result(s) using Ratliff's criteria. We recommend this procedure in cases with delayed initial appearance or failed previous surgery. Complications of the procedure such as long screw/graft and fibular fracture are preventable. The incidence of coxa vara in cases with neck resorption may be reduced by adding subtrochanteric osteotomy to the procedure.

An expansible cannula: a new technique for chest drain insertion

The insertion of a chest drain into the pleural space is a common procedure used by many specialties. The commonly used device is a prepacked, sterile plastic tube with its own central metal trocar. Complications may arise during its insertion, with the occasional penetration of intrathoracic and upper abdominal organs. As most chest drains are inserted by junior and relatively inexperienced doctors, it is therefore imperative that a simple, safe, and effective technique of insertion is found. A device has been developed that consists of a 5 cm conical length of an expansible cannula, made from rolled metal foil, which when inserted into the chest reaches only a few millimetres within the pleura. When an expander tube, 10 mm in diameter, is passed through the device from its proximal end the conical tube is distended into a hollow cylindrical one, through which a standard Portex chest catheter is passed. The whole appliance is then removed over the end of the tube, leaving the drain in situ. The efficacy of this unique device has been tested in a pilot study in 22 patients. There have been no complications.

The parasporal inclusion of Bacillus thuringiensis subsp. shandongiensis: characterization and screening for insecticidal activity

The parasporal body of Bacillus thuringiensis subsp. shandongiensis was characterized in terms of its structure, protein composition, and toxicological properties against several types of insects. The crystals of B. thuringiensis shandongiensis appear to consist of a major protein of 144 kDa present in an spherical inclusion, as determined by transmission electron microscopy, titration curve analysis, and SDS-PAGE of the solubilized crystals. A second protein of ca. 60 kDa is present in trace amounts and appears to be associated with a small bar-shaped inclusion. The 144-kDa protein has been characterized by isoelectric point determination, N-terminal amino acid sequence analysis, amino acid analysis, and immunological cross reactivity. Its N-terminal amino acid sequence differed from that of other B. thuringiensis crystal proteins. The 144-kDa protein was not immunologically related to the crystal proteins of two toxic serovars (B. thuringiensis israelensis and B. thuringiensis kurstaki HD-1) and one nontoxic serovar (B. thuringiensis indiana), as shown in immunoblots probed with antiserum raised against the 144-kDa B. thuringiensis shandongiensis protein, the B. thuringiensis israelensis crystal proteins, and the trypsin resistant fragment of B. thuringiensis kurstaki P1 proteins. In contrast to most B. thuringiensis serovars, B. thuringiensis shandongiensis crystals did not dissolve at pH 12. Solubilization was achieved in sodium bicarbonate at pH 8.3 and in the presence of 25 mM dithiothreitol.(ABSTRACT TRUNCATED AT 250 WORDS)

Maintenance of anaesthesia with propofol--a comparative study of a stepdown infusion of propofol and a low dose infusion supplemented by incremental doses

Forty-four patients, ASA Grade I or II, had anaesthesia induced with propofol at 100 mg min-1 followed by a maintenance rate of 6 mg kg-1 h-1 or a stepdown regimen of 10 mg kg-1 h-1 for 10 min, 8 mg kg-1 h-1 for the next 10 min and at 6 mg kg-1 h-1 thereafter. Anaesthesia was maintained with propofol infused using an Ohmeda 9000 pump supplemented by nitrous oxide and oxygen (2:1) in a Bain circuit with spontaneous ventilation. Incremental doses of 20 mg of propofol were given to both groups as clinically indicated to maintain anaesthesia. Both methods provided satisfactory maintenance of anaesthesia but significantly more incremental doses were required in the group receiving the steady rate infusion. However, a lower cumulative dose was required up to 30 min in this group but not by 40 min. A comparable fall in systolic and diastolic blood pressure and heart rate was seen in both groups. There was no difference in the recovery times between the groups and the total dose did not correlate with time to recovery.

Properties of a 72-kilodalton mosquitocidal protein from Bacillus thuringiensis subsp. morrisoni PG-14 expressed in B. thuringiensis subsp. kurstaki by using the shuttle vector pHT3101

The mosquitocidal properties of Bacillus thuringiensis subsp. israelensis and B. thuringiensis subsp. morrisoni PG-14 are attributable to protein inclusions grouped together within a parasporal body. In both of these strains, the mosquitocidal activity resides in proteins with molecular masses of 27, 72, 128, and 135 kDa. In an attempt to determine the toxicity of each protein, the shuttle vector pHT3101 was used to express the cryIVD gene (encoding the 72-kDa CryIVD protein) from B. thuringiensis subsp. morrisoni in an acrystalliferous mutant of B. thuringiensis subsp. kurstaki. With this system, parasporal inclusions of the 72-kDa protein were obtained that were comparable in size, shape, and toxicity to those produced by parental B. thuringiensis subsp. morrisoni. The inclusions were bar shaped, measured 500 by 300 by 150 nm, and were easily visible with phase-contrast microscopy by 16 h of cell growth. A 50% lethal concentration of 64 ng/ml for these inclusions was determined in bioassays against fourth instars of Culex quinquefasciatus, which was similar to the 50% lethal concentration of 55 ng/ml obtained for the 72-kDa inclusion from B. thuringiensis subsp. israelensis. In contrast, expression of the cryIVD gene in Escherichia coli was very low and only detectable by immunoblot analysis. These results demonstrate that the pHT3101-B. thuringiensis expression system can be used to express the CryIVD protein in quantities and with properties comparable to that obtained with the natural host. This system may prove useful for the expression of other B. thuringiensis proteins and, in particular, for reconstitution experiments with inclusions produced by the mosquitocidal subspecies of B. thuringiensis.