Split-thickness skin excision in severe open fractures

Split-thickness skin excision can be used as a one-stage procedure for the accurate diagnosis of flap viability and the immediate treatment of friction-avulsion injuries in severe open fractures. After cleaning the wound, the avulsed flap is temporarily sutured back to its original bed and a split thickness graft is taken from it and meshed to a 1:3 ratio. Surface dermal capillary bleeding then serves as an indicator of viability, clearly displaying a line for the excision of devascularized skin and correlating well with a concomitant fluorescein test. The wounds are re-opened and, after fixation of the fracture, the viable part of the flap is returned to its original bed and the remaining defects are covered with the meshed graft. We have treated 16 patients with extensive degloving injuries in this way, 15 needing only the single surgical procedure. All retained flaps survived, no other donor sites were needed and the split-thickness grafts took with 90% to 100% success.

Cerebral vasculitis associated with hairy cell leukemia

Hairy cell leukemia was diagnosed in a 74-year-old man. He was followed for 5 years when he developed confusion and focal neurological signs. Despite investigation and treatment he died. Postmortem study revealed isolated primary necrotizing vasculitis affecting the cerebral arteries. No leukemic infiltration of the central nervous system was found. There is a recognized association between hairy cell leukemia and generalized necrotizing vasculitis of polyarteritis type, however, this is the first case report of isolated cerebral vasculitis associated with this condition. The importance of excluding infective (mycotic) arteries in this type of case is emphasized.

ELISA measurement of IgG subclass production in culture supernatants using monoclonal antibodies

Specific and sensitive ELISA to quantitate the human IgG subclasses in cell culture supernatants are described. These assays detect a minimum of 5 ng/ml IgG1, 90 ng/ml IgG2, 8 ng/ml IgG3 and 8 ng/ml IgG4 and can generally measure IgG subclasses in lymphocyte cultures containing a minimum of 200 ng/ml of total IgG. The isotype specificity of these ELISA is demonstrated and each individual ELISA shown to react with a number of paraproteins of the relevant subclass independently of their light chain type or their (major Caucasian) allotype. These assays have been used to determine the IgG subclass response of normal human lymphocytes to pokeweed mitogen in vitro.

Modulation of the murine immune response to human IgG by complexing with monoclonal antibodies. I. Antibody responses to determinants on the constant region of light chains and gamma chains

Complexing a human IgG lambda paraprotein with a monoclonal antibody (McAb) to a lambda-chain determinant markedly depressed the anti-lambda response of immunized mice. No anti-lambda was found in the serum after two or four injections of the complex, whereas high titres of anti-lambda chain antibody were found in the sera of mice immunized with the IgG paraprotein complexed with any single anti-gamma chain McAb or with a pool of anti-gamma chain McAbs. Responses to the highly immunogenic Fc gamma portion of the molecule were not suppressed by complexing with a single anti-gamma chain McAb and were only slightly suppressed after complexing with a pool of anti-gamma chain McAbs. Some anti-Fc gamma antibody was produced by all animals receiving a single injection of the immunogen complexed to any McAb, but free immunogen did not generate a primary response. Complexing the IgG with an anti-Fc gamma McAb enhanced the response to to the poorly immunogenic C gamma 1 domain but no anti-C-gamma 1 was produced by mice receiving the IgG complexed with an anti-C-gamma 1 McAb. In immunizations with 'free' (Bence-Jones) lambda chain, all the antibody produced was directed against 'free'-specific determinants. Complexing the Bence-Jones protein with McAbs to 'free' or 'general' determinants on the lambda chain did not enhance or suppress the response. It is concluded that the response to weakly or moderately immunogenic, but not to strongly immunogenic, regions of the molecule may be suppressed by complexing the immunogen with a McAb of appropriate specificity. Possible reasons for this result are discussed.

Modulation of the murine immune response to human IgG by complexing with monoclonal antibodies. II. Antibody responses to idiotopes of the human IgG paraprotein and of the mouse monoclonal antibodies

Anti-idiotope antibodies produced by mice immunized with a human IgG paraprotein complexed with various mouse monoclonal antibodies (McAbs) have been measured. All animals receiving more than one injection of the paraprotein (free or complexed with a mouse McAb) produced antibodies to the idiotypes of the paraprotein. Complexing with a McAb, especially an anti-Fc-gamma McAb, enhanced the response. Antibodies to the idiotopes of mouse McAbs were more difficult to produce and their production was very dependent on the mode and schedule of the immunization. The best antisera were produced by mice receiving a course of injections of pre-formed complexes of the IgG paraprotein and McAbs. Four of five mice produced antibodies to the idiotopes of an anti-light chain McAb (C4) after a course of immunization (one primary plus four boosts) of an IgG-C4 complex. Two of the six mice receiving a similar course of injections of the paraprotein complexed with an anti-gamma McAb (A55) produced high titres of antibodies to A55 idiotypes. Responses were enhanced when complexes were prepared with a pool of McAbs. It is probable that the formation of large multi-cross-linked complexes containing the McAb under study is important in generating the response. Once a response is initiated, very high titres may be achieved.

Spondylolysis in the upper lumbar spine. A study of 32 patients

Reports of spondylolysis in vertebrae other than those of the lower lumbar spine are rare. We report 32 patients with upper lumbar spondylolysis who have been studied clinically, radiologically and scintigraphically. Twenty patients had bilateral lesions, and seven of those with unilateral lesions had structural changes or anomalies in the opposite posterior arch. Positive scans were found to be associated with a short clinical history, and indicated stress-related lesions. Our findings suggest that mechanical factors may play a role in the aetiology of spondylolysis in the upper lumbar spine similar to that which they play in the lower lumbar spine, and that local structural anomalies may contribute to abnormal loading of these vertebrae.

Unusual combination of Monteggia, Colles', and navicular fractures

A rare combination of an ulnar fracture with posterior dislocation of the head of the radius and intraarticular fracture of the distal radius concomitant with an ipsilateral navicular fracture is presented. To the best of our knowledge, no such case has been reported. The mechanism of this fracture combination is discussed with respect to its role in producing the Monteggia type II fracture. Treatment consisted of a combination of closed and open reduction with external fixation.

Sequence analysis in the E1 region of adenovirus type 4 DNA

Adenovirus type 4 (Ad4) is the sole member of adenovirus group E based on overall DNA sequence homology, restriction endonuclease cleavage patterns, and the size of capsid proteins. We cloned the BamHI-F fragment from the left end of Ad4 in pUC13-1 between the SalI and BamHI sites in order to carry out the structural analysis of the E1A region of Ad4. The complete sequence of the BamHI-F fragment (2042 bp) has been determined. From the DNA sequence, the splice sites for the putative 12 S and 13 S mRNAs, encoded by the E1A region of Ad4 were deduced. If protein synthesis initiates at the first available AUG triplet (position 575), these 12 S and 13 S mRNAs would code for polypeptides containing 226 and 257 amino acids, respectively. Comparison of Ad4- and Ad7-13 S mRNA-coded polypeptides indicates that there is 57% homology, whereas the homology is only 38% with Ad12 and 31% with Ad2-13 S mRNA-coded polypeptides. The structural analysis in the E1 region of Ad4 also includes the coding region for the E1B 19-kDa protein. Ad4 and Ad7 shows 65% homology in the coding regions for E1B 19-kDa protein. Comparison of the DNA sequence of Ad4 with those of Ad2, Ad7, and Ad12 by using a dot matrix computer program and by Southern hybridization revealed that Ad4 bears a stronger homology with Ad7 than with Ad2 and Ad12 in this region. Hydropathy plots and alignments of the putative polypeptides coded by this region in Ad4 with those from the corresponding regions of different serotypes to reveal the highly conserved domains also support the above conclusion.

Cerebral and orbital Aspergillus infection due to invasive aspergillosis of ethmoid sinus

Aspergillus fumigatus infection due to primary infection of the ethmoid sinus affected the brain and orbit of an otherwise healthy elderly woman. Primary nasal sinus infection may be a chronic process analogous to aspergilloma of the lung: it may, however, assume a locally invasive course and spread to the orbit or brain, as in the case described. This form of Aspergillus infection is rare in Europe but common in hot dry areas like the Sudan. The infection was probably contracted by our patient while on holiday in South Africa. Histological recognition of the condition is important in these unusual sites--many cases are clinically diagnosed as a tumour and undergo biopsy.

Studies on the reappearance of MHC class II antigens on cells of a variant human lymphoblastoid line

EB4 lymphoblastoid cell line cells were cultured for 32 days with a ricin A chain-conjugated monoclonal antibody (McAb) to a beta chain determinant present on DP and DR antigens. A single colony of cells which survived this treatment was grown up and surface expression of MHC class II and B cell antigens measured. All class II antigens (DQ as well as DP and DR, alpha as well as beta chains) were initially greatly diminished, but substantial recovery of expression occurred within 20-100 days of culture (approx. 21-105 generations), although recovery was still incomplete. The CD19 (p95) B cell antigen was present in greater amount and the CD22 B cell antigen and surface immunoglobulin in lower amount on the variant line cells. It was confirmed that unconjugated anti-class II McAb binds to surface antigens but is unable to induce modulation even over an 8-day culture period. Evidence is presented that the gradual re-expression of class II antigens on the variant line cells is not due to the appearance of a mutant or to recovery from modulation. It is suggested that the variant line cells produce an excess of a regulatory molecule when grown in the conjugate.

Immunogenicity and antigenicity of immunoglobulins. XII. Intact light chain and heavy chain isotype-restricted Vk-associated epitopes

Immunization with intact IgG has allowed the isolation of four hybridomas producing antibodies recognizing epitopes expressed within subpopulations of human kappa light chains unrelated to known polymorphisms (Km) and previously defined V-region subgroups. The V-region-associated epitopes recognized are conformation-dependent, being expressed on intact light chain but not on isolated VK or CK fragments. The frequency of expression within paraprotein panels of different heavy chain isotypes varied between individual antibodies. An epitope recognized by B2A6, expressed by greater than 85% IgGK paraproteins, was not represented in 16 IgM paraproteins tested, suggesting that association of VK with mu chains does not result in display of the epitope recognized, or alternatively, that selective association between VK and CH gene products occurs. These data contrast with the reactivity of other McAb for CK epitopes which were reactive with isolated CK fragments, and for all kappa-bearing paraproteins, regardless of heavy chain isotypes.

The effects of spinal injury on the intensity of emotional experience

Twenty-nine subjects with spinal lesions were asked whether the intensity of their experience of eight common emotions had decreased, increased or stayed the same since injury. Analysis of their responses produced no evidence of a decline in affective tone following spinal injury.

Evaluation of monoclonal antibodies having specificity for human IgG sub-classes: results of an IUIS/WHO collaborative study

Seventy-four monoclonal antibodies (McAb) of putative specificity for human IgG (11), the IgG sub-classes (59) or Gm allotypes (4) have been evaluated for reactivity and specificity in eight laboratories employing different assay techniques or protocols. For the IgG, IgG3, IgG4, G1m(f) and G3m(u) specificities McAb have been produced that can be satisfactorily applied in most methodologies employed and have potential as reference reagents. The IgG1 and particularly IgG2 specificities proved problematical with all McAb evaluated demonstrating apparent assay restriction and whilst performing well in some assays proved to be poor or inactive reagents in others. However, the study identifies McAb individually suited to application within most commonly employed methodologies. Epitope display is the probable variability rather than capricious behaviour by the McAb. IgG1 and IgG2 were the least immunogenic of the sub-class proteins and there is evidence that epitope display is influenced by the physical and chemical procedures used to immobilize or fix antigen - a common requirement in the assay systems studied.

A new assay for IgG rheumatoid factor activity and its use to analyse rheumatoid factor reactivity with human IgG isotypes

A new assay for IgGRF activity is described which employs human IgGFc as the antigen and a radiolabelled monoclonal antibody directed against human IgG (CHI domain) as the developing antibody. Using this assay IgGRF activity against human IgG isotypes was measured and most sera from RA patients were shown to react predominantly with IgG1 and IgG2 but few reacted with IgG3 and IgG4. The same sera were tested for IgMRF to the IgG isotypes. IgG2 was the best antigen, IgG1 and IgG4 were less so and reactivity with IgG3 was the lowest. IgGRF without associated IgMRF was obtained, its specificity compared to that of IgMRF, and found to be broadly similar. With the new assay high levels of serum IgGRF were found in those RA patients with extraarticular disease but not in RA patients with synovitis alone.

Monoclonal antibodies to an immunoglobulin allotype marker G1m(f)

The properties of a group of mouse monoclonal antibodies (McAbs) specific for the human G1m(f) allotype marker on immunoglobulin G are described. The specificity of all 5 McAbs was anti-Gm(f) in haemagglutination assays detecting the G1m(f) determinant on 6 ng of purified G1m(f) paraproteins. A high dilution (greater than or equal to 1/10(4)) could be used for the majority of McAbs in this assay. In Elisa the G1m(f) marker could be detected in homozygote G1m(f+z-) sera at a serum dilution of greater than or equal to 1/10(4). In Elisa assays the G1m(f) specificity was lost when IgG was bound directly to polystyrene but was restored when IgG was bound via anti-human IgG to the polystyrene plate. A possible conformational change in IgG to account for this loss of specificity is discussed. It is expected that these McAbs with their high titre and increased sensitivity over conventional Gm antisera will allow more detailed analysis of the Gm marker system.

Significance of bone scintigraphy in symptomatic spondylolysis

In a prospective study, the authors evaluated the usefulness of bone scintigraphy in the work-up of young military personnel with lumbar spondylolysis and persistent low back pain. Ten out of 23 spondylolytic individuals with a recent history of low back pain had positive scintigrams, and none of a group of painless spondylolytic individuals had positive scans. We believe these results indicate that bone scintigraphy is of value in determining whether a spondylolysis in a young individual can be attributed to recent physical exertion or a specific recent traumatic incident.