Clinical efficacy and safety of nabumetone in rheumatoid arthritis and osteoarthritis. The efficacy and safety of nabumetone were evaluated in short term (up to 6 months), double blind, comparative trials and a longterm (up to 8 years), open label, noncomparative trial. In the short term trials, nabumetone was determined to be significantly more effective than placebo and as effective as naproxen and aspirin. The most common adverse effects that occurred were related to the gastrointestinal tract, nervous system, skin, and special senses. In the longterm trial, nabumetone was effective in 62% of patients, without complicating effects, for at least 1 year. This beneficial response was maintained in a fair percentage of patients for up to 5 years or more. The average treatment duration before withdrawal was at least 1.1 years. Therefore, most patients in the longterm trials experienced a beneficial response for a significant duration of therapy.


Nabumetone compared with naproxen in the treatment of rheumatoid arthritis: a multicenter, double blind, randomized, parallel group trial in hospital outpatients. In this double blind, randomized, parallel group study, 298 patients with rheumatoid arthritis received nabumetone (2000 mg/day) or naproxen (1000 mg/day) for 3 months. At the end point, nabumetone treated patients exhibited significant improvement in pain, Ritchie articular index, and duration of morning stiffness when compared to baseline. In contrast, naproxen treated patients showed significant improvement only in Ritchie articular index. Nabumetone was significantly more effective than naproxen for pain relief. More nabumetone treated patients withdrew due to lack of efficacy than naproxen treated patients. However, nabumetone was better tolerated than naproxen because fewer patients withdrew for adverse events or experienced severe adverse events, and significantly fewer patients required treatment for adverse events.


Worldwide safety experience with nabumetone. Nabumetone has undergone human clinical premarketing and postmarketing testing for efficacy and safety for about 10 years. In the United States and elsewhere, 7,241 patients were evaluated in clinical trials and comparative information with placebo, aspirin, and other nonsteroidal antiinflammatory drugs (NSAID) was gathered. Postmarketing surveillance information was gathered for 37,712 patients in the United Kingdom and Germany. Withdrawal rates due to adverse effects ranged from 3 to 13%. The cumulative incidence of nabumetone-induced perforations, ulcers, or bleeds varied from 0.02 to 0.95%. In all patients evaluated, only 2 deaths and 15 hospitalizations could be attributed to nabumetone therapy. Bone marrow suppression, liver necrosis, serious central nervous system conditions, or life-threatening dermatologic reactions did not occur. No increase in toxicity was noted with increased dose (up to 2000 mg/day) or age. Nabumetone was determined to be a safe NSAID that causes a low incidence of ulcers.


Nabumetone compared with indomethacin in the treatment of osteoarthritis in general practice. In a double blind, randomized, parallel group study, 197 patients with osteoarthritis (OA) received nabumetone (1000 mg/day) or indomethacin (75 mg/day) for 6 weeks and doses could be doubled. Doubling the dose resulted in a 100 or 67% increase in pain relief with nabumetone or indomethacin, respectively. Significantly more patients experienced at least 1 severe adverse event with indomethacin than with nabumetone. With nabumetone, the incidence of adverse events did not increase with dose. However, with the increase in dose, the incidence of all adverse events and gastrointestinal events increased in indomethacin treated patients. Nabumetone was as effective as indomethacin for the treatment of OA. However, significantly fewer nabumetone treated patients experienced severe adverse events and the frequency of events did not increase with dose.


Association of nonsteroidal antiinflammatory drugs with upper gastrointestinal disease: epidemiologic and economic considerations. One of the major concerns regarding the use of nonsteroidal antiinflammatory drugs (NSAID) in the treatment of patients with arthritis is the high incidence of gastrointestinal (GI) side effects. Important issues regarding NSAID and upper GI complications include the following: (1) the magnitude of the association between NSAID therapy and clinically important gastric or duodenal ulcers or upper GI bleeding; (2) the subgroup(s) of patients who are at increased risk for upper GI side effects; and (3) the economic impact of NSAID induced upper GI toxicity. A causal association between NSAID use and the development of clinically important ulcer disease or its complications, including upper GI bleeding, is supported by available epidemiologic data. Furthermore, data suggest that up to one third of all direct costs of care may be attributed to the treatment of NSAID induced GI side effects. Approaches to this problem, such as the development of safer NSAID that are equally effective, need to be pursued.


NSAID, ulcers, and prostaglandins.

NSAID, ulcers, and prostaglandins. The pathogenesis of nonsteroidal antiinflammatory drug (NSAID) induced gastrointestinal (GI) injury is complex and includes contributions from direct topical injury and reduced mucosal resistance due to indirect or systemic inhibition of mucosal prostaglandin (PG) synthesis. Some NSAID that cause less inhibition of gastroduodenal PG synthesis appear to cause less GI injury. NSAID induced GI complications include adverse symptoms, endoscopically observable mucosal damage, and ulcer complications. Ulcers are common in patients taking NSAID and are often asymptomatic; however, they may bleed or perforate. Prevention of GI complications can be approached by concomitant administration of a protective drug or by developing a safer NSAID. However, limitations of concomitant therapy with existing protective drugs suggest that new NSAID should be developed that are less harmful to the GI tract.


Upper gastrointestinal safety with nabumetone. Nabumetone is a nonacidic nonsteroidal antiinflammatory drug (NSAID) that is effective and appears to cause minimal NSAID gastropathy. The lack of significant untoward gastrointestinal (GI) effects has been demonstrated in large and longterm clinical experiences. The United States Food and Drug Administration reports an annual ulcer incidence of 2 to 4% with chronic NSAID use. The ulcer incidence after therapy with nabumetone, however, is far below the reported range. Only 1 (0.1%) ulcer in 930 patients was determined clinically in United States short term (6-week to 6-month) double blind studies. Additionally, in the long-term (8-year), open label study, only 16 (0.95%) ulcers occurred in 1677 patients. Endoscopically determined ulcers, on the other hand, occur in about 20% of chronic NSAID users. In our short term (3-month) and longterm (5-year) endoscopically controlled study, a 5% (1 of 19 patients) ulcer incidence was determined. Overall, these results suggest a significantly reduced rate of ulcer development.


The selection of a nonsteroidal antiinflammatory drug. Is there a difference? The availability of an ever expanding number of nonsteroidal antiinflammatory drugs (NSAID) relates to their utility for the treatment of a broad spectrum of disorders. Both the efficacy and adverse effects of NSAID relate primarily to their antiprostaglandin mechanism of action, prostaglandin inhibition. At full antiinflammatory doses, there is little evidence to support a rank order of effectiveness. The major differences among NSAID are their half-lives and safety profiles. With newer agents the emphasis is on safety, especially with respect to gastrointestinal irritation. Acknowledgment of inherent drug differences with respect to pharmacology and safety enhances tolerability by the patient and increases the likelihood for continued drug therapy.


Problems that patients feel are appropriate to discuss with their GPs. A descriptive study was performed to discover what problems patients felt it appropriate to discuss with their general practitioner, their use of alternative therapies, and any questions they wished their doctor had asked them in the past. Demographic data was recorded including Church attendance. Data was collected using an original questionnaire distributed to two groups of patients; 150 consecutive patients attending the surgery (surgery group) and 220 randomly selected from the adult age-sex register (home group). Chi-squared analysis was performed. A broad range of subjects appropriate to a general practice consultation was found (from influenza to spiritual problems). Prior use of homeopathy and hypnosis was widespread. Multiple attenders were more likely to be church attenders. Men in the surgery group were most likely to discuss marital, relationship and spiritual problems. Qualitative data from open questions demonstrated patients' concerns with consultation time and the exploration of feelings.


The use of thromboprophylaxis in total hip replacement surgery: are the attitudes of orthopaedic surgeons changing? We conducted a survey of all 926 active members of the British Orthopaedic Association using a postal questionnaire to find out their current attitude to thromboprophylaxis in total hip replacement surgery. Previous surveys have been performed, and with all the recent literature on the subject we wanted to see if the attitude of British orthopaedic surgeons has changed. There were 676 replies, a response rate of 73%. Fifty-five replies were excluded, those from surgeons who had retired from practice or whose practice did not include total hip replacement surgery. Of the remaining 621 surgeons, 466 (75%) use some method of thromboprophylaxis, with 367 (59%) routinely using prophylactic pharmacological agents and 99 (16%) using mechanical methods of thromboprophylaxis. Twenty-five per cent (155) of surgeons used no routine method of thromboprophylaxis. Eight-six per cent (534) of surgeons used a pharmacological method of prophylaxis in those patients thought to have a high risk of developing a deep vein thrombosis (DVT) (eg previous DVT, cardiovascular disease, obesity). Thirty-two different methods of thromboprophylaxis were used. Low molecular weight heparin is now being used by 19% of surgeons routinely and by 25% of surgeons in high risk cases, whereas 3 years ago it was not used at all. Our survey shows that although there is still a great reluctance for British orthopaedic surgeons to use pharmacological agents routinely in thromboprophylaxis. Amongst those that do, low molecular weight heparin is being increasingly used. More surgeons may want to use low molecular weight heparin routinely, but in some hospitals it is not currently available.


Generic prescribing of antidepressants.

Generic prescribing of antidepressants. Analysis of National Health Service prescription data for the antidepressants from 1980 to 1989 shows a consistent secular trend towards the increased use of generic names on prescriptions for this group of drugs. This apparently reflects national trends for all drugs, and was similar for most antidepressants. However, generic prescribing had by 1989 increased significantly more rapidly with fluvoxamine, which was introduced in 1987. The two drugs introduced in 1989, fluoxetine and amoxapine, also had a high generic prescribing rate in their year of introduction. Increased generic prescribing may become a feature with further new drugs. However, the use of the generic name on the prescription has relatively little influence on what is dispensed to the patient. Pharmacists may dispense a brand name when given a generic prescription. Moreover, pressures on doctors to write generic names on prescriptions may have limited relevance for some drugs; generic alternatives were available for only four out of 22 antidepressants.


Vertical banded gastroplasty: is obesity worth it? Obesity is a public health issue of major concern for the United States and other developed nations. In the last several decades, bariatric surgery has developed as a means of treating morbid obesity. Vertical banded gastroplasty (VBG) is an attractive procedure because it has fewer side effects than other forms of bariatric surgery and maintains physiological continuity of the gut. VBG was performed in 36 patients at a rural community hospital from 1982-1990. There was only one intraoperative complication necessitating splenectomy and two early postoperative complications--gastric leak and marginal stress ulcer--necessitating reexploration. Twenty-five patients were available for follow-up, at which time they were an average of 6.4 years out of surgery. Two of these patients had died, both from cardiac arrest months or years after VBG. The remainder had gone from a preoperative average of 86.7% over ideal weight according to 1983 Metropolitan Life insurance Tables to 54.5% over ideal weight. Mean BMI for this group had changed from 41.2 preoperatively to 34.7 at follow-up. Success was defined as weight loss to < 60% over ideal or BMI < 35, removing the individual from the morbidly obese category. According to this criteria, VBG provided successful weight loss in 72% of subjects in the follow-up group. Weight loss results may have been biased as a significant number of patients were lost to follow-up and may have constituted failures. In general, most individuals did not make concomitant changes in diet or sedentary life-style which would have supported weight loss effected by VBG. Moreover, regain of weight was progressive and possibly inexorable. Nearly all individuals nonetheless reported great satisfaction with their surgery. VBG is a viable option in the treatment of morbid obesity, but criteria for success needs to be better defined in order to determine whether the procedure is "worth it."


Modulation of ultraviolet light mutational hotspots by cellular stress. Stressful treatments of cells provoke broad, transient, changes in cellular physiology and gene expression. In addition to these effects, DNA-damaging agents often induce permanent change in the form of mutations. Mutational patterns in target genes typically show hotspots and coldspots, the molecular basis of which appears to lie in the sequence context of the particular site. We determined the mutational pattern in an ultraviolet light-modified (in vitro) marker gene in a shuttle vector passaged through repair deficient (xeroderma pigmentosum) cells and compared it with patterns obtained from cells exposed to stress imposed by a DNA-damaging agent or a calcium ionophore. We found that the mutational hotspot pattern was altered by both stress treatments. We conclude that the cellular environment can influence the probability of mutagenesis at specific sites and propose that some of these effects on mutagenesis are mediated by alterations in cellular calcium levels.


Base pairing geometry in GA mismatches depends entirely on the neighboring sequence. We have synthesized nine self-complementary DNA oligomers containing different flanking sequences adjacent to a pair of contiguous GA mismatches, and have used high resolution nuclear magnetic resonance (n.m.r.) to investigate the GpA phosphodiester backbone conformation and mismatch pairing schemes in these duplexes. We found dramatic effects of the flanking base pair on the hydrogen bonding and backbone conformation, which appear to be coupled. Thus the Ganti-Aanti base pairing scheme in a NAGATN sequence switches to a more stable sheared GA base pairing scheme in a NCGAGN or NTGAAN context, while no duplex is formed (or only GA bulges occur) when NAGATN is changed to NGGACN. Furthermore, the more stable sheared GA pairing in NPyGAPuN sequences is associated with a BII rather than BI backbone conformation for the phosphodiester between the adjacent mismatched GA pairs. The overall stability of these adjacent GA mismatches as measured by imino proton n.m.r. studies is Py-GA-Pu > A-GA-T > G-GA-C.


Seven, eight and nine-membered anticodon loop mutants of tRNA(2Arg) which cause +1 frameshifting. Tolerance of DHU arm and other secondary mutations. The mutant tRNA(2Arg) encoded by the genetically-selected frameshift suppressor, sufT621, inserts arginine and causes a +1 reading-frame shift at the proline codon, CCG(U). There is an extra base, G36.1, in argV beta, one of the four identical genes for tRNA(2Arg) in the position between bases 36 and 37, corresponding to the 3' side of the anticodon. The new four-base anticodon, predicted from DNA sequencing to be 3' GGCA 5', is complementary to the four-base codon CCGU. Quadruplet translocation promoted by mutant argV does not require perfect complementarity between the codon and the anticodon since synthetic genes encoding derivatives of tRNA(2Arg) and tRNA(1Pro), with four-base anticodons complementary to three out of the four bases of CCGU, were also shown to be capable of frameshifting. Two other mutants of argV, inferred to have normal-size, seven-base anticodon loops, were also found to be capable of four-base-decoding demonstrating that quadruplet translocation promoted by mutant argV does not require an enlarged anticodon loop. Other alleles of argV, predicted to have nine bases in the anticodon loop, were also found to cause frameshifting. The DNA sequence of two of these showed in addition, either a deletion of G24, or a ten-base duplication in the region corresponding to the TFC arm. A general finding is that mutations in the DHU arm of tRNA(2Arg) are compatible with, and in one case necessary for, frameshifting.


Synthetase competition and tRNA context determine the in vivo identify of tRNA discriminator mutants. The discriminator nucleotide (position 73) in tRNA has long been thought to play a role in tRNA identity as it is the only variable single-stranded nucleotide that is found near the site of aminoacylation. For this reason, a complete mutagenic analysis of the discriminator in three Escherichia coli amber suppressor tRNA backgrounds was undertaken; supE and supE-G1C72 glutamine tRNAs, gluA glutamate tRNA and supF tyrosine tRNA. The effect of mutation of the discriminator base on the identity of these tRNAs in vivo was assayed by N-terminal protein sequencing of E. coli dihydrofolate reductase, which is the product of suppression by the mutated amber suppressors, and confirmed by amino acid specific suppression experiments. In addition, suppressor efficiency assays were used to estimate the efficiency of aminoacylation in vivo. Our results indicate that the supE glutamine tRNA context can tolerate multiple mutations (including mutation of the discriminator and first base-pair) and still remain predominantly glutamine-accepting. Discriminator mutants of gluA glutamate tRNA exhibit increased and altered specificity probably due to the reduced ability of other synthetases to compete with glutamyl-tRNA synthetase. In the course of these experiments, a glutamate-specific mutant amber suppressor, gluA-A73, was created. Finally, in the case of supF tyrosine tRNA, the discriminator is an important identity element with partial to complete loss of tyrosine specificity resulting from mutation at this position. It is clear from these experiments that it may not be possible to assign a specific role in tRNA identity to the discriminator. The identity of a tRNA in vivo is determined by competition among aminoacyl-tRNA synthetases, which is in turn modulated by the nucleotide substitution as well as the tRNA context.


Topography of transcription factor complexes on the Saccharomyces cerevisiae 5 S RNA gene. Locations of component proteins of yeast RNA polymerase III transcription factors (TFIII) A, C and B on a 5 S rRNA gene have been determined by site-specific DNA-protein photo-crosslinking. Comparison with a previously analyzed tRNA gene shows that similar nucleoprotein structures assemble on these two genes despite their differently located internal promoter elements. A principal signature of this homology is the placement of the 95 kDA subunit of TFIIIC, which associates with the box A promoter element of the tRNA gene. On the 5 S rRNA gene, the 95 kDa subunit occupies the same space in the absence of a box A sequence, and despite the presence of a box A-like sequence 30 base-pairs further downstream. A 90 kDa component that was not previously recognized as an integral part of TFIIIC has been specifically located at the 3' end of the 5 S rRNA gene.


Structural requirements for the processing of Escherichia coli 5 S ribosomal RNA by RNase E in vitro. Processing of 9 S precursor RNA in Escherichia coli requires the endoribonuclease RNase E, which makes two cleavages to liberate p5, the immature form of 5 S rRNA. The contributions of primary and secondary structure to RNase E-mediated cleavage of 9 S RNA were investigated. The structure of the 5' domain of 9 S RNA was probed by partial ribonuclease digestion and chemical modification. Our structural analysis of 9 S RNA supports a model in which the 5' spacer domain folds into tandem hairpins so that the first processing cleavage site 5' to the 5 S moiety resides in a stretch of single-stranded residues. Site-directed mutagenesis of a cloned 9 S RNA sequence was performed and synthetic transcripts derived from a variety of such mutant templates were assayed as substrates for RNase E-dependent endonuclease activity in fractionated extracts. Partial or complete deletion of the 5 S sequence did not eliminate site-specific processing of 9 S RNA. Mutations affecting the 5' domain revealed that secondary structure upstream from the first cleavage site is important in maintaining efficient processing. However, secondary structure downstream from either cleavage site is dispensable. Our results suggest that RNase E specifically recognizes and cleaves single-stranded RNA sequences only when presented in a proper conformational context. Adjacent secondary structures appear to play a direct and critical role in the enzyme's recognition of its substrate. Additionally, it may serve to anchor single-stranded regions to ensure the availability of the RNase E cleavage sites.


Functional analysis of Box II mutations in yeast site-specific recombinases Flp and R. Significance of amino acid conservation within the Int family and the yeast sub-family. The site-specific recombinases Flp and R from Saccharomyces cerevisiae and Zygosaccharomyces rouxii, respectively, are related proteins that share approximately 30% amino acid matches. They exhibit a common reaction mechanism that appears to be conserved within the larger Integrase family of site-specific recombinases. Two regions of the proteins, designated as Box I and Box II, harbor, in addition to amino acid conservation, a significantly high degree of nucleotide sequence homology within their coding segments. Box II also contains two amino acids, a histidine and an arginine, that are invariant throughout the Int family. We have performed functional analysis of Flp and R variants carrying point mutations within the Box II segment. Several positions within Box II can tolerate substitutions with no effect, or only modest effects on recombination. Alterations of the Int family residues, His305 and Arg308, in the R protein lead to the arrest of recombination at the strand cleavage or the strand exchange step. This is very similar to previously observed "step-arrest" phenotypes in Flp variants altered at these positions and has strong implications for the catalytic mechanism of recombination. Flp and R variants at His305 and His309 can be complemented in half-site strand transfer by a corresponding Tyr343 to phenylalanine variant. In contrast to Arg308 Flp variants, which are efficiently complemented in half-site strand transfer by Flp(Y343F), no strong complementation has been observed between Arg308 variants of R and R (Y343F).


Zinc induces a bend within the transcription factor IIIA-binding region of the 5 S RNA gene. Binding of Zn2+ to the 5 S RNA gene sequence of Xenopus borealis results in strong bending of the DNA, as inferred from transient electric birefringence data. The effect is specific for Zn2+; several other divalent ions are not able to induce a bend of a similar magnitude. Using five different fragments that span the binding sequence, we are able to estimate a bend magnitude of at least 55 degrees centered at base-pair +65 within the gene. This places the bend within the binding domain of the gene-regulatory protein transcription factor (TF) IIIA. Recent evidence has shown that the protein-DNA complex is also bent. Although our data do not allow us directly to link the two bends, our results suggest that TFIIIA could form a folded structure by stabilizing the same bent conformation that is induced by binding of Zn2+. The chemistry of Zn2+ binding to DNA, and the sequence around the bend center, suggest that the bend is most probably caused by joint co-ordination of Zn2+ to the N-7 groups of stacked purine residues.


Features of spliceosome evolution and function inferred from an analysis of the information at human splice sites. An information analysis of the 5' (donor) and 3' (acceptor) sequences spanning the ends of nearly 1800 human introns has provided evidence for structural features of splice sites that bear upon spliceosome evolution and function: (1) 82% of the sequence information (i.e. sequence conservation) at donor junctions and 97% of the sequence information at acceptor junctions is confined to the introns, allowing codon choices throughout exons to be largely unrestricted. The distribution of information at intron-exon junctions is also described in detail and compared with footprints. (2) Acceptor sites are found to possess enough information to be located in the transcribed portion of the human genome, whereas donor sites possess about one bit less than the information needed to locate them independently. This difference suggests that acceptor sites are located first in humans and, having been located, reduce by a factor of two the number of alternative sites available as donors. Direct experimental evidence exists to support this conclusion. (3) The sequences of donor and acceptor splice sites exhibit a striking similarity. This suggests that the two junctions derive from a common ancestor and that during evolution the information of both sites shifted onto the intron. If so, the protein and RNA components that are found in contemporary spliceosomes, and which are responsible for recognizing donor and acceptor sequences, should also be related. This conclusion is supported by the common structures found in different parts of the spliceosome.


Structure-related properties of the mutagenic lesion 6-O-methylguanine in DNA. Chemical probing of the structures of a few very similar 30 base-pair duplexes containing a 6-O-methylguanine (meG) residue at the 16th position reveals that the modified base simultaneously perturbs the helical structure in two ways; it preferentially unstacks the 3' neighbouring base residue (thymine in this study) on the same strand and it unstacks the pyrimidine to which it is base-paired. Depending on its neighbouring 5' base residue and the base-pairing pyrimidine, this perturbation can extend to a few base-pairs in both 3' and 5' directions from the abnormal base-pair. These perturbations can be detected by cleavage at the site for the restriction enzyme MaeII. The unstaking of the C in the meG.C and A.C base-pairs may explain the de novo methylation of these helices by the human DNA-(cytosine-5-)methyltransferase. Interestingly, the kinetics of repair of the 6-O-methylguanine-containing dinucleotides by the cloned human methylguanine methyltransferase appears to be largely determined by the strength of the stacking interaction between the 6-O-methylguanine and the 5' neighbouring base.


Organization and ordered expression of Caulobacter genes encoding flagellar basal body rod and ring proteins. The biogenesis of the polar flagellum in Caulobacter crescentus is limited to a specific time in the cell cycle and to a specific site on the cell. The basal body is the first part of the flagellum to be assembled. In this report we identify a cluster of genes encoding basal body components and describe their transcriptional regulation. The genes in this cluster form an operon whose expression is controlled temporally. The first two genes encode homologs of FlgF and FlgG, which are the proximal and distal rod proteins, respectively. The sequences of the N and C termini of the Salmonella typhimurium flagellar axial proteins, rod, hook and HAP-1, known to be highly conserved, share a high degree of sequence identity with the FlgF and FlgG rod proteins of the distantly related, C. crescentus. Two additional genes in the flgF, flgG operon, flaD and flgH, both encode proteins with potentially cleavable signal sequences. The flgH gene, encoding the L-ring protein, is also transcribed from an internal promoter. Transcription from the flgF promoter initiates prior to initiation at the internal flgH promoter. The internal promoter and its activator site reside within the C-terminal coding sequence of the upstream flaD gene. This type of gene overlap is also observed in bacterial genes involved in cell division. Flagellum biogenesis, like cell division, is a morphogenic event that requires the orderly assembly of component proteins and the overlapping gene organization may affect this "ordering" of assembly. The promoters for the flgF operon and the flgH gene use sigma 54 to initiate transcription. The use of sigma 54 promoters, known to require cognate binding proteins, could allow the fine-tuning that provides the temporal ordering of flagellar gene transcription. In this context, we have found that the flgF operon and the distal flgI gene encoding the P-ring, share a sigma 54 activator sequence (class IIA) that differs from the flgH L-ring gene sigma 54 activator site (class IIB) and the hook cluster (class IIC) sigma 54 activator site. The sequential activation of these three subgroups of structural genes reflects the order of assembly of their gene products into the flagellum.


Calmodulin structure refined at 1.7 A resolution. We have determined and refined the crystal structure of a recombinant calmodulin at 1.7 A resolution. The structure was determined by molecular replacement, using the 2.2 A published native bovine brain structure as the starting model. The final crystallographic R-factor, using 14,469 reflections in the 10.0 to 1.7 A range with structure factors exceeding 0.5 sigma, is 0.216. Bond lengths and bond angle distances have root-mean-square deviations from ideal values of 0.009 A and 0.032 A, respectively. The final model consists of 1279 non-hydrogen atoms, including four calcium ions, 1130 protein atoms, including three Asp118 side-chain atoms in double conformation, 139 water molecules and one ethanol molecule. The electron densities for residues 1 to 4 and 148 of calmodulin are poorly defined, and not included in our model, except for main-chain atoms of residue 4. The calmodulin structure from our crystals is very similar to the earlier 2.2 A structure described by Babu and coworkers with a root-mean-square deviation of 0.36 A. Calmodulin remains a dumb-bell-shaped molecule, with similar lobes and connected by a central alpha-helix. Each lobe contains three alpha-helices and two Ca2+ binding EF hand loops, with a short antiparallel beta-sheet between adjacent EF hand loops and one non-EF hand loop. There are some differences in the structure of the central helix. The crystal packing is extensively studied, and facile crystal growth along the z-axis of the triclinic crystals is explained. Herein, we describe hydrogen bonding in the various secondary structure elements and hydration of calmodulin.


Impact of protein-protein contacts on the conformation of thrombin-bound hirudin studied by comparison with the nuclear magnetic resonance solution structure of hirudin(1-51). The impact of protein-protein interactions on the conformation of the N-terminal hirudin domain consisting of residues 1 to 51 in the X-ray crystal structure of a hirudin-thrombin complex was investigated through comparisons with the nuclear magnetic resonance solution structure of hirudin(1-51). The close overall similarity observed between these two structures contrasts with the behavior of the C-terminal 17-residue polypeptide segment of hirudin, which is flexibly disordered in solution but exhibits a defined conformation in the complex with thrombin. Localized structural differences in the N-terminal domain include that residues 1 to 3 of hirudin in the crystalline complex form a hydrogen-bonding network with thrombin that is reminiscent of a parallel beta-sheet. Moreover, the backbone conformation of residues 17 to 20 in the complex does not contain the characteristic hydrogen bond observed for the type II' reverse turn in the solution structure, and the side-chains of Ser19 and Val21 have significantly different orientations in the two structures. Most of these structural changes can be related directly to thrombin-hirudin contacts, which may also be an important factor in the mechanism of hirudin action. In this context, it is of special interest that other residues that also make numerous contacts with thrombin, e.g. Thr4, Asp5 and Asn20, have identical conformations in free hirudin and in the complex.


Structure of cobalt carbonic anhydrase complexed with bicarbonate. The three-dimensional structure of a complex between catalytically active cobalt(II) substituted human carbonic anhydrase II and its substrate bicarbonate was determined by X-ray crystallography (1.9 A). One water molecule and two bicarbonate oxygen atoms are found at distances between 2.3 and 2.5 A from the cobalt ion in addition to the three histidyl ligands contributed by the peptide chain. The tetrahedral geometry around the metal ion in the native enzyme with a single water molecule 2.0 A from the metal is therefore lost. The geometry is difficult to classify but might best be described as distorted octahedral. The structure is suggested to represent a water-bicarbonate exchange state relevant also for native carbonic anhydrase, where the two unprotonized oxygen atoms of the substrate are bound in a carboxylate binding site and the hydroxyl group is free to move closer to the metal thereby replacing the metal-bound water molecule. A reaction mechanism based on crystallographically determined enzyme-ligand complexes is represented.


Determination of the solution structures of domains II and III of protein G from Streptococcus by 1H nuclear magnetic resonance. We have used 1H nuclear magnetic resonance spectroscopy to determine the solution structures of two small (61 and 64 residue) immunoglobulin G (IgG)-binding domains from protein G, a cell-surface protein from Streptococcus strain G148. The two domains differ in sequence by four amino acid substitutions, and differ in their affinity for some subclasses of IgG. The structure of domain II was determined using a total of 478 distance restraints, 31 phi and 9 chi 1 dihedral angle restraints; that of domain III was determined using a total of 445 distance restraints, 31 phi and 9 chi 1 dihedral angle restraints. A protocol which involved distance geometry, simulated annealing and restrained molecular dynamics was used to determine ensembles of 40 structures consistent with these restraints. The structures are found to consist of an alpha-helix packed against a four-stranded antiparallel-parallel-antiparallel beta-sheet. The structures of the two domains are compared to each other and to the reported structure of a similar domain from a protein G from a different strain of Streptococcus. We conclude that the difference in affinity of domains II and III for IgG is due to local changes in amino acid side-chains, rather than a more extensive change in conformation, suggesting that one or more of the residues which differ between them are directly involved in interaction with IgG.


Crystallization and preliminary X-ray studies of the pectate lyase from Bacillus subtilis. The pectate lyase (EC 4.2.2.9) from Bacillus subtilis has been crystallized. Crystals of form 1, grown by the hanging drop method using polyethylene glycol as precipitant, diffract to at least 2.4 A resolution. They belong to the spacegroup P2(1) with a = 132.9 A, b = 41.2 A, c = 156.8 A and beta = 114.9 degrees with probably four molecules in the asymmetric unit. A second crystal form grown from 2-methyl-2,4-pentandiol also belongs to the spacegroup P2(1) with a = 55.0 A, b = 88.1 A, c = 50.2 A and beta = 109.0 degrees. These crystals diffract to at least 2.0 A and have one molecule in the asymmetric unit. Both crystal forms are suitable for the determination of high-resolution structures.


Purification and crystallization of the light harvesting LH1 complex from Rhodobacter sphaeroides. The LH1 light harvesting complex has been purified from a mutant of the photosynthetic bacterium Rhodobacter sphaeroides which synthesizes LH1 as the sole pigment protein. Crystallization trials using polyethylene glycol as the precipitant in the presence of the detergent n-octyl glucoside have resulted in the formation of needle like crystals which diffract beyond 3.5 A and which are relatively resistant to radiation damage. X-ray photographs have established that the crystals belong to the tetragonal system and are probably in space group P4(2)2(1)2. Estimates of the crystal density indicate that the asymmetric unit of the crystals contains two oligomers each with an alpha 6 beta 6 stoichiometry.


Crystallization and preliminary X-ray analysis of human angiogenin. Crystals of recombinant human angiogenin have been grown from solutions containing sodium potassium tartrate and polyethylene glycol as precipitants. They belong to the space group C222(1) (a = 83.36 A, b = 120.64 A, c = 37.72 A) and contain a single molecule in the asymmetric unit. The crystals diffract to at least 2.3 A resolution and are suitable for three-dimensional X-ray structural analysis.


Crystallization and preliminary X-ray diffraction analysis of a plant ribonuclease from the seeds of the bitter gourd Momordica charantia. Single crystals of ribonuclease Mc, a new class of plant ribonuclease from the seeds of the bitter gourd, were obtained from solutions of polyethylene glycol 8000 by the hanging-drop vapour diffusion method. The crystals belong to the orthorhombic space group P2(1)2(1)2(1) with cell dimensions a = 67.28 A, b = 75.21 A, c = 38.54 A. The assumption of one monomer per asymmetric unit gives rise to a Vm value of 2.29 A3/Da. The crystals diffract beyond 2.0 A resolution and are suitable for high resolution X-ray structure analysis.


A study of ovarian follicular kinetics, oviduct, fat body, and liver mass cycles in laboratory-maintained Rana cyanophlyctis in comparison with wild-caught frogs. Ovarian follicular dynamics and fluctuations in fat body, oviducal, and liver masses were studied in captive Rana cyanophlyctis in comparison with wild-caught frogs, sampled at monthly intervals over a period of 12 months. In both the captive and wild-caught frogs first growth phase (FGP) and second growth phase (SGP) or vitellogenic oocytes were produced throughout the period examined; however, changes in ovarian and oviducal weights were less marked in the former group. In the captive frogs SGP oocyte production was reduced by 50%, and, maximum ovarian weight and SGP oocyte number were attained 2-3 months earlier than in wild-caught controls. The FGP oocyte pool in laboratory-maintained frogs, however, was comparable with that of the corresponding wild-caught frogs. Captivity caused a threefold increase in atresia and reduced the number of oocytes reaching SGP. The depletion of fat stores in fat bodies during the later phases of captivity suggests that the deposition of lipids into oocytes (for SGP) was given priority over storage in the fat bodies. The low oviducal weights of captive frogs was correlated with a reduced number of SGP oocytes, which are the source of estrogen. On the other hand, liver weight remained high, indicating adequate hepatic vitellogenin synthesis. Possible reduction in its output was not detected, possibly due to the reduced number of follicles reaching SGP. The findings indicate that stress of captivity decreases gonadotrophins and estrogen levels. Oviducal growth is reduced in captive frogs.(ABSTRACT TRUNCATED AT 250 WORDS)


Muscles of the pelvic outlet in the fowl (Gallus gallus domesticus) with special reference to their nerve supply. The manner of innervation of the pelvic outlet muscles in fowl (Gallus gallus domesticus) was examined in detail in four male pelvic halves. The segmental arrangement of the nerve supply in the sacral and pudendal plexuses was compared to that of Lacertilia and Urodela as a basis for a morphological analysis of the pelvic outlet muscles. From the viewpoint of innervation, the pelvic outlet muscles of fowl are classified into two groups: a sphincter muscle group and a levator muscle group. These two groups are closely related to the ventral muscles of the pelvic limb. In contrast to the morphology of pelvic outlet muscles in lacertilians, in fowl the caudal muscle element does not contribute to the formation of these muscles.


Comparative skeletogenesis of the forearm of the little brown bat (Myotis lucifugus) and the Norway rat (Rattus norvegicus). This study describes, quantifies, and compares the growth and development of the volant forelimb morphology of Myotis lucifugus with that of the terrestrial forelimb morphology of Rattus norvegicus. In M. lucifugus there is 1) accelerated growth in forearm length after parturition, 2) cessation in growth of the midshaft diameter of the ulna just after the onset of osteogenesis, 3) proximal fusion of the radius and ulna, which results in the radius occupying 97% of the articular surface of the elbow joint in adults, 4) fusion between the cartilaginous distal epiphyses of the radius and ulna which results in formation of a radioulnar bridge that becomes fully ossified in adults, and 5) incomplete ossification of the ulna with a section of the diaphysis becoming ligamentous. None of these events occurs during development in R.norvegicus.


Specialized veins in the submucosa of the equine ileocecal junction. Spirally arranged bundles of sub-endothelial smooth muscle enfold the small to medium-sized submucosal veins in the equine ileocecal junction. The muscle bundles, accompanied by the endothelial lining, bulge into the lumen of the vessels, partly occluding the latter. Transmission electron microscopy of the muscle cells reveals features consistent with vascular smooth muscle ultrastructure. It is proposed that the throttling effect of the muscle bundles causes engorgement of the submucosal venous plexus, which then assists in the closing of the ileocecal orifice.


Stereotaxic atlas of the brain of Octodon degus. We present a stereotaxic atlas of the brain of the trumpet-tailed rat or degu (Octodon degus), an hystricomorph rodent native to Chile and one which has become increasingly popular as a research animal, among other things because of its use as a model for diabetic cataracts and its tendency to become hyperglycemic. The atlas contains 38 transverse and two sagittal sections of the brain covering pros-, mes-, and rhombencephalon, as well as diagrams of the brain's surface anatomy. It was constructed from brains of young adult male degus but can be used readily in studies of adult females, since there is no apparent sexual dimorphism in the brain size of this rodent. Ninety percent of 40 experimental lesions used to check the accuracy of the atlas were correctly placed. The fore- and midbrain of the degu are generally more compact than corresponding regions of the brain in the laboratory rat (suborder Myomorpha) and the guinea pig (another hystricomorph). The amygdaloid complex extends further forward in the telencephalon. Major mesencephalic nuclei and fiber tracts are more rostral in position. However, superior and inferior colliculi are much longer in degus than rats. The basic organization of the rhombencephalon is similar in degus and rats, although there are clearcut differences in the length or size of some hindbrain nuclei.


Sutural complexity in artificially deformed human (Homo sapiens) crania. The pattern of complexity of cranial sutures is highly variable both among and within species. Intentional cranial vault deformation in human populations provides a controlled natural experiment by which we were able to quantify aspects of sutural complexity and examine the relationship between sutural patterns and mechanical loading. Measures of sutural complexity (interdigitation, number, and size of sutural bones) were quantified from digitized tracings of 13 sutures and compared among three groups of crania (n = 70) from pre-European contact Peru. These groups represent sample populations deformed in 1) anteroposterior (AP) and 2) circumferential (C) directions and 3) an undeformed population. Intergroup comparisons show few differences in degree or asymmetry of sutural interdigitation. In the few comparisons which show differences, the C group is always more interdigitated than the other two while the AP group has more sutural bones. The sutures surrounding the temporal bone (sphenotemporal, occipitotemporal, and temporoparietal) most frequently show significant differences among groups. These differences are related to the more extreme binding of C type deformation and are consistent with hypothesized increases in tension at coronally oriented sutures in this group. The larger number of sutural bones in the AP group is consistent with the general broadening of the cranium in this group and with experimental evidence indicating the development of ossicles in areas of tension. We suggest that so few changes in sutural complexity occurred either because the magnitude of the growth vectors, unlike their direction, is not substantially altered or because mechanisms other than sutural growth modification are responsible for producing the altered vault shapes. In addition, the presence of fontanelles in the infant skulls during binding and the static nature of the binding may have contributed to the similarity in complexity among groups.


Functional implications of neural canal anatomy in recent and fossil marine carnivores. A statistical and functional relationship between neural canal anatomy and locomotor mode is demonstrated in living marine mammals of the Order Carnivora. This relationship is interpreted to be the result of differential innervation and territory of musculature involved in generating the six locomotor patterns analyzed. This osteological reflection of a behavioral trait allows prediction of locomotor pattern in extinct genera of closely related taxa. The robust data allow such predictions even when a considerable number of presacral vertebrae are missing in the fossil specimens. In some cases, these predictions conflict with interpretations based solely on limb osteology.


The evolution of coexisting highly divergent LINE-1 subfamilies within the rodent genus Peromyscus. Two distinct members of the LINE-1 (L1) family in Peromyscus were characterized. The two clones, denoted L1Pm55 and L1Pm62, were 1.5 kb and 1.8 kb in length, respectively, and align to the identical region of the L1 sequence of Mus domesticus. Sequence similarity was on the order of 70% between L1Pm55 and L1Pm62, which approximates that between either Peromyscus sequence and Mus L1. L1Pm62 represents a more prevalent subfamily than L1Pm55. L1Pm62 exists in about 500 copies per haploid genome, while L1Pm55 exists in about 100 copies. The existence of major and minor subpopulations of L1 within Peromyscus is in contrast to murine rodents and higher primates, where L1 copy number is on the order of 20,000 to 100,000, and where levels of intraspecific divergence among L1 elements are typically less than 15-20%. Additional Peromyscus clones are similarly divergent from both L1Pm62 and L1Pm55, implying the existence of more than two distinct L1 subfamilies. The highly divergent L1 subfamilies in Peromyscus apparently have been evolving independently for more than 25 million years, preceding the divergence of cricetine and murine rodents. Investigations of the evolution of L1 within Peromyscus by restriction and Southern analysis was performed using species groups represented by the partially interfertile species pairs P. maniculatus-P. polionotus, P. leucopus-P. gossypinus, and P. truei-P. difficilis of the nominate subgenus and P. californicus of the Haplomylomys subgenus. Changes in L1 and species group taxonomic boundaries frequently coincided. The implications for phylogeny are discussed.


Nucleotide variation and molecular structure of the heterochromatic repetitive AluI DNA in the brine shrimp Artemia franciscana. It has been suggested that DNA bending could play a role in the regulation of gene expression, chromosome segregation, specific recombination and/or DNA packaging. We have previously demonstrated that an AluI DNA family of repeats is the major component of constitutive heterochromatin in the brine shrimp A. franciscana. By the analysis of cloned oligomeric (monomer to hexamer) heterochromatic fragments we verified that the repetitive AluI DNA shows a stable curvature that determines a solenoidal geometry to the double helix. This particular structure could be of relevant importance in conferring the characteristic heterochromatic condensation. In this paper we evaluate how the point mutations that occurred during the evolution of the AluI sequence of A. franciscana could influence the sequence-dependent tridimensional conformation. The obtained data underline that, in spite of the high sequence mutation frequency (10%) of the repetitive DNA, the general structure of the heterochromatic DNA is not greatly influenced, but rather there is a substantial variation of the copy number of the repetitive AluI fragment. This variation could be responsible for the hypothetical function of the constitutive heterochromatin.


Evidence for retrotranscription of protein-coding genes in the Drosophila subobscura genome. Evidence is provided for the presence of retrosequences (also named retroposons) arising from Adh in the Drosophila subobscura genome. Restriction analysis and primary structure of two different retrosequence-containing clones, S812 and S135, are reported. The fact that these retrosequences lack introns and a recognizable promoter strongly supports their retrotranscriptional origin. Adjacent to the two retrosequences analyzed, a middle repetitive DNA element has been found which bears no clear similarity to any sequence reported to date in the GenBank/EMBL Data Library. A comparative analysis of these retrosequences with the functional Adh gene of D. subobscura is presented. In addition, a model concerning the origin, functionality, and propagation of these genome elements is discussed.


Evolution of linear plasmids.

Evolution of linear plasmids. Linear plasmids are genetic elements commonly found in yeast, filamentous fungi, and higher plants. In contrast to all other plasmids they possess terminal inverted repeats and terminal bound proteins and encode their own DNA and RNA polymerases. Here we present alignments of conserved amino acid sequences of both the DNA and RNA polymerases encoded by those linear plasmids for which DNA sequence data are available. Additionally these sequences are compared to a number of polymerases encoded by related viral and cellular entities. Phylogenetic trees have been established for both types of polymerases. These trees appear to exhibit very similar subgroupings, proving the accuracy of the method employed.


Is higher-order structure conserved in eukaryotic ribosomal DNA intergenic spacers? Computer-based structural analysis of the ribosomal DNA intergenic spacer (IGS) from the mosquito Aedes albopictus revealed a potential to form strong and extensive secondary structures throughout a 4.7-kilobase (kb) region. The predicted stability of secondary structures was particularly high within a 3.15-kb region containing 17 tandem 201 base-pair subrepeats. Similarly strong secondary structure potential was also found when IGS subrepeats were analyzed from 17 phylogenetically diverse eukaryotes, including vertebrates, invertebrates, and plants. Conservation of higher-order structure potential in the IGS region of ribosomal DNA may reflect evolutionary and functional constraints on chromatin organization, transcriptional regulation of the ribosomal RNA genes, and/or transcript processing and stability.


Phylogeny of the alpha-crystallin-related heat-shock proteins. Phylogenetic relationships were examined among 35 alpha-crystallin-related heat-shock proteins from animals, plants, and fungi. Approximately one-third of the aligned amino acids in these proteins were conserved in 74% of the proteins, and three blocks of consensus sequence were identified. Relationships were established by maximum parsimony and distance matrix analyses of the aligned amino acid sequences. The inferred phylogeny trees show the plant proteins clearly divided into three major groups that are unrelated to taxonomy: the chloroplast-localized proteins and two groups that originate from a common ancestral plant protein. The animal proteins, in contrast, branch in accordance with taxonomy, the only clear exception being the alpha-crystallin subgrouping of vertebrates. This analysis indicates that the small heat-shock proteins of animals have diverged more widely than have the plant proteins, one group of which is especially stable.


An electromechanical spinal injury technique with dynamic sensitivity. Over the past decade, our laboratory has attempted to create a simple, accurate device that could be used to produce reliable and quantifiable spinal cord injuries in the rodent. We report here on our latest of several modifications of a spinal cord impactor that has allowed us to meet these design criteria. The impactor uses the dynamic capacity of an electromagnetic driver (Ling shaker) and a unique pattern generator to briefly compress the dorsal surface of the spinal cord at velocities that may mimic compression injuries seen in the human. Calibrated, independent transducer systems provide open-loop output of the precise movement (displacement) of the impactor probe and the force necessary to achieve a given displacement. Touch sensitivity is accomplished by vibrating the probe slightly as it approaches the dural surface. This also allows a known biomechanical starting point. This combination of improvements in sensitivity and ability to measure all components of the dynamic compression has allowed us to determine detailed biomechanical descriptors of these impact injuries with low coefficients of variation. Furthermore, such descriptors correlate highly with histopathologic and behavioral outcome measures in animal populations with a variety of injury severities.


Spinal cord injury produced by consistent mechanical displacement of the cord in rats: behavioral and histologic analysis. We examined the ability of an electromechanical device to produce consistent and incomplete thoracic (T9) spinal cord injuries in rats by brief displacement (Dspl) of the exposed dural surface. Open field walking, inclined plane, grid walking, and footprint analysis, and a determination of the percentage of tissue spared at the lesion center were used to assess chronic outcome (6 weeks postinjury). Laminectomy control animals showed no evidence of a functional deficit or histologic lesion. Complete spinal cord transections in normal rats and in a group of animals previously injured (1.1 mm Dspl) and allowed to recover resulted in complete loss of hindlimb function, demonstrating an important functional role for the remaining spared fibers at the lesion site. Consistent spinal cord displacements (0.80 mm, 0.95 mm, and 1.10 mm) resulted in behavioral groups with low outcome variability over a narrow range of incomplete recovery of neurologic function. Significant behavioral (open field walking, inclined plane, and grid walking) and histologic differences were found between the control and Dspl groups and between the 0.80 mm and 1.10 mm Dspl groups. Significant correlations were observed among the injury parameters, behavioral, and histologic scores. Open field walking and inclined plane performance were sensitive indicators of both the early and late phases of neurologic recovery. Grid walking was most useful in animals with small chronic residual deficits. The footprint analysis resulted in less significant correlations and differences between the behavioral groups than the other outcome measures. This may result from a relatively narrow range of sensitivity (open field walking scores between 3.3 and 4.0) and increased variability within the groups.


Lesions of cat sacrocaudal spinal cord: a minimally disruptive model of injury. As part of our studies of the organization of the cat sacrocaudal spinal cord (S3-Ca7), the portion of the neuraxis that innervates the tail, we have begun to evaluate the behavioral effects of hemisection or complete transection at the level of Ca1. Clinical observations that the tail strongly deviated to the side of a hemisection indicated the presence of an ipsilateral hypertonia. After complete transection of the spinal cord, the tail became ventroflexed in a midline position and exhibited spasticity, i.e., hypertonia, hyperreflexia, and clonus. Bowel and bladder functions and hindlimb gait and reflexes remained intact following either lesion. Quantitative behavioral measures corroborated our clinical observations. With the tail tethered to a force transducer, tail muscle tone was measured after the tail was passively positioned. Following a transection, resistance to dorsiflexion of the tail was greater than resistance to ventroflexion. In addition, tonic deviation of the tail was documented with videotape analysis while cats walked on a plank. Normal cats walked with the tail sharply dorsiflexed and centered. In contrast, the tail deviated ipsilaterally in cats with a hemisection, and the tail was ventroflexed in cats with a transection. These observations indicate that the sacrocaudal spinal cord provides a model with special advantages for investigation of changes in segmental motor functions following spinal cord injury. The effects of lesions on the tail are quantifiable and can resemble that spasticity observed after spinal cord injury in humans. Importantly, minimal effects on locomotive and autonomic functions were observed following hemisection or transection of the sacrocaudal spinal cord.


Effects of dorsal column demyelination on evoked potentials in nucleus gracilis. Intraspinal injections of lysolecithin were used to produce unilateral demyelination in the dorsal columns of the rat spinal cord. The purpose of this study was to evaluate the effects of demyelination on the conductive properties of axons belonging to a spinal pathway of known origin and site of termination. At 5 and 50 day intervals following injections, animals were prepared for acute experiments during which recordings of tibial nerve evoked potentials were made from the surface of the lumbar spinal cord (L5-L6) and nucleus gracilis (0.5-1.0 mm caudal to obex). Latency, duration, and strength of potentials were evaluated in control (uninjected) and lysolecithin-injected animals. The analysis of these potentials showed increases in latency and decreases in duration and strength of responses recorded 5 days after lysolecithin injections. Animals examined 50 days postinjection showed a decreased latency and increased duration and strength of responses compared to those recorded 5 days postinjection. Ultrastructural examination of lysolecithin injection sites showed these improvements to parallel the remyelination of axons by oligodendrocytes and Schwann cells. The improvement in physiologic characteristics of evoked potentials coupled with the remyelination of dorsal column axons supports the conclusion that remyelination of chemically demyelinated axons is an important factor in reestablishing the functional connectivity of demyelinated axons.


Microtubule-associated protein 2 levels decrease in hippocampus following traumatic brain injury. We examined microtubule-associated protein 2 (MAP2) levels in hippocampal and cortical tissue 3 h following moderate traumatic brain injury (TBI) in the rat. MAP2 levels were assayed by quantitative immunoreactivity in tissue fractions obtained from naive, sham-injured, or fluid percussion-injured animals. Tissues were homogenized in the presence of protease inhibitors (0.3 mM phenylmethylsulfonyl fluoride, PMSF), a specific calpain inhibitors (0.1 mM leupeptin), and chelators (2 mM ethylene glycol-bis-tetraacetic acid, EGTA; 1 mM ethylenedinitrilo-tetraacetic acid, EDTA) to eliminate in vitro MAP2 proteolysis during tissue processing. Compared to naive rats, sham injury had no effect on soluble MAP2 levels in either cortex (105.0 +/- 4.4% of naive value) or hippocampus (106.6 +/- 5.2% of naive value). However, TBI caused a significant (p < 0.005) decrease in hippocampal MAP2 levels (55.7 +/- 5.9% of sham-injured controls). The effect appeared to be regionally selective, since the MAP2 decrease did not occur in cortex (89.1 +/- 1.4%). The degree of MAP2 decrease in hippocampus was similar in both membrane (57.8%) and cytosolic (55.7%) fractions, ruling out the possibility of partitioning artifacts. The data suggest that sublethal alterations of neuronal structure and function caused by MAP2 degradation may play an important role in the development of TBI-induced functional deficits. Since MAP2 is exclusively associated with the cytoskeleton in somal and dendritic compartments of neurons, the pathophysiology of sublethal magnitudes of TBI may also involve dendritic and somal dysfunction.


Drug-specific immune responses induced by immunization with drugs in guinea pigs and mice. In order to develop a system for evaluating the allergenicity of drugs in clinical use, we tested drugs for the ability to induce drug-specific immune responses in guinea pigs and mice. Test drugs were benzylpenicillin, procainamide, hydralazine, isoniazid, alpha-methyldopa, D-penicillamine, captopril, sulfamethoxazole and 2,4-dinitrochlorobenzene (DNCB), which are known to induce allergic responses in man including hypersensitivity reactions and drug-induced auto-immune responses. Guinea pigs were immunized with an emulsion of complete Freund's adjuvant (CFA) and 25 mg of each drug. Mice were immunized with an emulsion of CFA and 2 mg of each drug or a mixture of aluminum hydroxide gel and 2 mg of each drug. In order to examine drug-specific immune responses, we employed detection of antibodies by enzyme-linked immunosorbent assay (ELISA) and passive cutaneous anaphylaxis tests, active systemic anaphylaxis (ASA) tests and delayed type hypersensitivity (DTH) tests. In guinea pigs, drug-specific antibodies were detected following immunization with benzylpenicillin, procainamide, hydralazine, isoniazid, captopril, sulfamethoxazole or DNCB. Some of these drugs were also positive in DTH tests and/or ASA tests. In mice, however, only DNCB gave positive results. Therefore, our system involving immunization of guinea pigs with CFA emulsion of a drug and detection of drug-specific immune responses is considered to be an effective test method for evaluating drug allergenicity.


Effect of estrogen on liver plasma membrane in rats. The effect of estrogen on plasma membrane was investigated using the primary cultured rat hepatocytes treated with carbon tetrachloride (CCl4) and the isolated plasma membrane of rat liver. 17 beta-Estradiol (E2), at concentrations of 10(-10) M to 10(-4) M, 10(-8) M to 10(-6) M and 10(-12) M to 10(-4) M, had an inhibitory effect on the CCl4-induced leakage of glutamic oxaloacetic transaminase, glutamic pyruvic transaminase and lactate dehydrogenase, respectively from primary cultured rat hepatocytes. Diethylstilbestrol, which caused inhibition at a dose of 10(-4) M, did not inhibit any enzyme leakage at any further concentrations of 10(-12) M to 10(-6) M. In the isolated plasma membrane of rat liver, Mg(2+)- and Na+,K(+)-adenosine triphosphatase activity was increased by E2 treatment at concentrations of 10(-6) M and 10(-4) M.


Species difference in susceptibility to phorbol myristate acetate-induced leukopenia and lung injury: rat vs. dog. Phorbol myristate acetate (PMA) was administered intravenously in a single dose to rats (400 micrograms/kg) and in a single and repeated doses to dogs (40 micrograms/kg). Severe leukopenia was observed in both species. The leukopenia in rats was due to a decreased number of both lymphocytes and neutrophils while the leukopenia in dogs was mainly due to a decreased number of neutrophils. The rats recovered from leukopenia much faster than the dogs. The dog which received a single injection developed focal fibrosis in the lungs. Rats showed only slight localized hemorrhage in the lungs, although the rats received a ten-fold larger dose of PMA than the dogs. Lungs of dogs which received multiple injections revealed severe hemorrhagic lesions in most alveoli. Lung lesions induced by PMA are thought to be mediated by activated leukocytes. This suggests that the severity of lung lesion correlates with the degree and duration of neutropenia. In conclusion, intravenous administration of PMA caused lung damage in rats and dogs. However, rats show much less sensitivity to PMA than dogs, resulting from the different response of leukocytes to PMA.


Appropriate conditions for the plaque forming cell (PFC) assay in rats and effects of cyclophosphamide on PFC response. The appropriate conditions for the plaque forming cell (PFC) assay using rat splenocytes were determined and effects of cyclophosphamide on PFC response were investigated using these conditions. The number of PFCs produced by immunization with a suspension of sheep red blood cells (SRBCs) was higher with i.v. injection than with i.p. injection. Subcutaneous injection of the suspension did not produce PFCs. The highest PFC response was observed when the number of PFCs was determined 4 days after i.v. immunization with 0.5 ml of a 1% SRBC suspension. Cyclophosphamide (3, 10, 30, 100 and 300 mg/kg, p.o.) dose-dependently decreased PFC response under the above-mentioned optimal conditions, and decreased PFC responses were noted even at the very low dose of 3 mg/kg: a dose at which a decrease in the number of PFCs has not been reported in studies using mice. From these results, the appropriate conditions for the PFC assay in rats are considered to be i.v. immunization with 0.5 ml of a 1% SRBC suspension and determination of the number of PFCs 4 days after immunization. Furthermore, it is considered that the PFC assay using rats might be more sensitive to immunosuppressive agents than that using mice.


Carcinogenicity examination of 1-nitropyrene oxides and related chemicals: lack of their tumorigenic effects in a newborn mice assay. Carcinogenicity of 1-nitropyrene (NP) oxides (1-NP 4, 5-oxide and 1-NP 9, 10-oxide) and related chemicals (1-NP and 1-nitro-6-hydroxypyrene) was examined in the newborn mouse model by i.p. administration at 1, 8, 15 days after birth (each chemical was given at a total dose of 700 nmol per mouse). Low incidences of hepatocellular neoplasms were recognized in male mice exposed to either of these chemicals. However, the incidences were not significantly different from those of animals given solvent alone or of non-treatment. Lymphoma was infrequently seen in female mice given some of tested chemicals. The incidences were also not significantly different from those of mice with the solvent alone or of the controls. The results suggest that although these aromatic hydrocarbons exert genotoxicity or mutagenicity, they may not be potent carcinogens, or the assay with use of newborn mice may be insufficient to monitor carcinogenicity of such chemicals.


Cytotoxicity of nickel oxide particles in rat alveolar macrophages cultured in vitro. The cytotoxicity of two types of nickel oxide particles was investigated in rat alveolar macrophages cultured in vitro. The trypan blue dye exclusion test and the release of lactate dehydrogenase into culture medium were used as cytotoxic indices. Although both types of nickel oxide particles were produced by the same manufacturer and were commercially sold under the same name of "nickel oxide", one type of the nickel oxide particles which had black color was much more cytotoxic than the other type of green color. The black nickel oxide particles were more soluble in various kinds of solutions than the green nickel oxide particles. Therefore, it appears that the difference in the cytotoxicity of the black and green nickel oxide particles may be attributable to the difference in the solubility of the particles.


Leukotriene generation in patients with multiple injuries. We determined the generation and metabolism of lipoxygenase products in isolated granulocyte fractions of patients with multiple trauma (n = 9) and compared the results with those of healthy volunteers (n = 8). The supernatants of stimulated cells were analyzed by high-performance liquid chromatography. During the first week after injury a significantly reduced capacity to generate LTB4 and an increased metabolism of LTB4 into omega-oxidated products (20-OH-LTB4 and 20-COOH-LTB4) were observed after stimulation of the granulocytes with Ca ionophore. The depressed leukotriene production could be partly abrogated by the addition of arachidonic acid. These findings are comparable with alterations previously described in severely burned patients with postburn sepsis. Additionally, an elevated production of LTC4 by peripheral granulocyte fractions was observed in two patients suffering from adult respiratory distress syndrome (ARDS) as well as an increased number of eosinophils during the time of lung dysfunction. Analysis of bronchoalveolar lavage in patients with multiple trauma (11 patients with ARDS and 11 patients without ARDS) by a specific radio-immunoassay confirmed an elevated production of cysteinyl-leukotrienes.(ABSTRACT TRUNCATED AT 250 WORDS)


Components of the increased circulating proteolytic activity in pediatric burn patients. Total proteolytic activity (PA) is increased in the circulation of pediatric burn patients. The extent of the increase correlates with the percent total body surface area (TBSA) burned and is associated with increased susceptibility to fatal infection. To determine the source or sources of this PA, three factors were evaluated: (1) levels of proteinase inhibitors--antithrombin, alpha 2-antiplasmin, and alpha 1-proteinase inhibitor; (2) levels of proteinase--neutrophil elastase; and (3) activation of circulating proteolytic cascade systems as indicated by changes in levels of system components--plasminogen and prekallikrein. All assays measured functional levels of the proteins. Normal levels were determined in 25 consecutive well children who were seeing their pediatrician for checkups (14 boys, 11 girls, ranging in age from 10 months to 17 years). Twenty-five consecutive burn victims admitted to the Shriners Burns Institute, Cincinnati Unit (19 boys, six girls, aged 10 months to 17 years), with a mean full-thickness burn of 43.2% TBSA (range, 6%-87%) were studied in the first week postburn. Antithrombin, alpha 2-antiplasmin, plasminogen, and prekallikrein levels decreased (p < 0.001) postburn, whereas elastase increased (p < 0.001). We conclude that, in pediatric burn patients, decreased proteinase inhibitors, increased proteinase, and activation of circulating proteinase cascades all contribute to elevated total circulating PA postburn.


Prediction of acute renal failure following soft-tissue injury using the venous bicarbonate concentration. Sixty-four patients with soft-tissue injuries were studied prospectively to determine whether an initial venous bicarbonate concentration (VBC) of less than 17 mmol/L would predict the development of myoglobin-induced acute renal failure. The VBC was > 17 mmol/L in 59 patients, seven of whom had myoglobinuria. All recovered without renal complications. The remaining five patients all had VBC < 17 mmol/L and four had myoglobinuria. Acute renal failure developed in four patients (p < 0.001). The VBC on hospital arrival was the most accurate predictor of these patients' risk for the development of acute renal failure following soft-tissue injury.


Burns in morbidly obese patients.

Burns in morbidly obese patients. It has been estimated that 26% of Americans are obese. A very small subset of this group can be categorized as morbidly obese, fulfilling the criteria of being 100 pounds, or 100%, over ideal body weight. The clinical records of seven morbidly obese burn patients treated over a 20-year period are reviewed. Particularly notable was a 43% incidence of fatal pulmonary embolism.


Immediate positive pressure ventilation with positive end-expiratory pressure (PEEP) improves survival in ovine smoke inhalation injury. The purpose of this study was to compare the effects of immediate initiation of positive pressure ventilation (PPV) with positive end-expiratory pressure (PEEP) versus the initiation of PPV with PEEP only after hypoxemia ensued following severe smoke inhalation injury. We prospectively evaluated chronically instrumented adult sheep treated with immediate versus delayed PPV with PEEP and compared oxygen requirements, hemodynamics, pleural fluid formation, postinjury survival, and tracheobronchial pathologic processes among groups. The immediate group (group I; smoke, n = 6; sham, n = 2) underwent tracheostomy and bilateral chest tube placement before they received inhalation injury. They were then immediately placed on PPV with PEEP (12 cm H2O). The animals in the delayed group (group D) (n = 6) were placed on PPV with PEEP when arterial hypoxemia (PaO2 < 80 mm Hg [11.2 kPa] on 0.4 FIO2) or respiratory distress developed. Groups were matched for smoke exposure and peak carboxyhemoglobin. Both groups developed a characteristic decrease in PaO2/FIO2 ratio. Initiation of PPV + PEEP improved PaO2 in the delayed group (69 +/- 7 to 126 +/- 21 mm Hg [9.2 +/- 0.9 to 16.7 +/- 2.8 kPa]). Pleural fluid output was greater in the immediate group compared with the delayed group (1559 +/- 415 vs. 426 +/- 236 mL). At 96 hours after injury five of six animals in the delayed group had died. In contrast, six of six animals in the immediate smoke group survived 96 hours (p < 0.05 versus delayed group). The immediate group had fewer and less extensive tracheobronchial casts at necropsy. Immediate PPV + PEEP did not prevent the development of hypoxia and was associated with increased pleural fluid formation. Death within 96 hours in the delayed group was the result of respiratory failure aggravated by bronchial cast formation despite vigorous pulmonary toilet. Early positive pressure ventilation with PEEP, preferably initiated immediately after the inhalation insult, significantly increases short-term survival and is associated with decreased tracheobronchial cast formation in this ovine model of severe smoke inhalation injury.


Noninvasive assessment of metabolism in wounded skin by 31P-NMR in vivo. Phosphorus-31 nuclear magnetic resonance techniques using shallow penetrating coils have been used to noninvasively monitor severity and metabolic changes over time in skin wounds in rats. Ratios of phosphocreatine (PCr) to inorganic phosphate (Pi) indicate energy status in both thermal wounds and surgical flaps. In partial and full-thickness scald wounds, reductions in PCr/Pi ratios correlated with burn depth and improved over time postinjury, suggesting wound revascularization. No decrease in intracellular pH was noted in these wounds; the phosphate shifts may be primarily the result of tissue degradation followed by restoration of the microvasculature. Distal regions of caudally based dorsal 3 x 10 cm full-thickness skin flaps reveal progressively lower PCr/Pi ratios to 3-6 hours after elevation as well as drops in pH up to 0.5 units, presumably as a result of anaerobic glycolysis in these tissues. After 24 hours, the intracellular pH returned to normal (7.1-7.2) and the PCr/Pi ratios approached 70%-90% of the well-perfused proximal regions within 3-7 days. These results indicate the establishment of a microvasculature from the underlying bed as the distal regions survive as free grafts. The data demonstrate the potential usefulness of the technique in noninvasive measurement of the biochemical response to injury and wound healing in living organisms.


The effects of hypothermia and injury severity on blood loss during trauma laparotomy. To assess the relationships between core temperature (T) and other factors relating to operating room (OR) blood loss and mortality following abdominal injury, the records of 122 patients undergoing laparotomy for trauma at Detroit Receiving Hospital over a 1-year period (1989) were reviewed. Most injuries were penetrating (86%) and the mortality rate was 8.2%. Overall, 57 of 122 (47%) had hypothermia (T < or = 35 degrees C) upon arrival in the OR. There was a significant correlation between admission blood pressure and lowest intraoperative temperature (r = 0.60; p < 0.001). Multiple regression analysis revealed that the patient's lowest temperature (p < 0.001) and Trauma Score (TS); p < 0.0015), but not Abdominal Injury Severity Score (AISS) (p = 0.25) correlated with OR blood loss. The 28 patients with high TS (15 or 16) and AISS > or = 9 had significantly less blood loss when the OR temperature was maintained above 35 degrees C versus 33 degrees-35 degrees C (540 +/- 580 mL vs. 1820 +/- 1160 mL; p < 0.003). This suggests that hypothermia may exacerbate OR blood loss independent of degree of physiologic or anatomic injury. Thus hypothermia is common in patients undergoing a laparotomy for trauma. Trauma scores and the presence of shock preoperatively correlate with the development of intraoperative hypothermia. Hypothermic patients with similar injury severity have greater blood loss. Prevention and rapid correction of hypothermia during resuscitation and surgery appear to be extremely important in reducing blood loss in this patient population.


Reconstruction of skeletal defects in the femur with 'two-strut' free vascularized fibular grafts. Large skeletal defects of the femur caused by infected nonunions remain a challenge to orthopedic surgeons. Conventional bone grafting may not succeed when the recipient bed is not ideal. Single fibular grafts were proven very useful in bridging this type of defect, yet were complicated by the high incidence of refracture and the need for protection of long duration. By dividing the fibula into two struts connected by the nutrient vessels, we doubled the effective cross-sectional area of bone grafting with only one set of vascular anastomoses. Five cases of infected nonunion of the femur after a high-energy trauma were successfully managed with this technique. All the fractures healed in an average of 7 months. By 1 year the grafts hypertrophied to the size of the femur. A follow-up of at least 2 years recommends this technique in the management of certain chronic osseous defects of the femur.


An autopsy case review of 142 nonpenetrating (blunt) injuries of the aorta. This study retrospectively reviewed 142 fatal cases of aortic laceration. Data were collected from the autopsy reports (including toxicology results) and included the circumstances of the injury. In the case of automobile crashes this included the direction of impact, time of day, and vehicular damage. Seventy percent of the victims were men with a mean age of 37.5 years; 30% were women with a mean age of 46 years. Thirty-five percent of the 142 victims had elevated blood alcohol levels. Fifty-four percent of the lacerations were located at the classic site (the isthmus). The majority of the aortic lacerations (102) were sustained in automobile crashes. Of these, 42% were broadside collisions and 58% were head-on collisions. Seventy-three percent and 67% of the victims in broadside and head-on collisions, respectively, had aortic lacerations at the classic site. The results suggest that the pathogenesis of aortic rupture involves a lateral oblique compression impact to the chest, which causes thoracic mediastinal structures to shift and deflect the aortic arch, resulting in severe shearing and stretching at the isthmus. The use of seat belts and air bags may reduce the number of aortic injuries.


The association of advanced life support training and decreased per capita trauma death rates: an analysis of 12,417 trauma deaths. This study identified a number of significant predictors of per capita county trauma mortality rates: rurality, percentage nonwhite population, percentage unemployment, and Advanced Life Support (ALS) versus Basic Life Support (BLS) status. Of these, ALS versus BLS status is not only the most significant independent predictor, it is the only predictor readily amenable to change. The aspects of ALS clearly associated with decreased trauma death rates should be identified and, if possible, undergo widespread implementation.


The 1991 Fraser Gurd Lecture: evolution of airway control in the management of injured patients. The evolution of methods for airway control has been an important factor in improving overall trauma care. Many important advances have been made in technique, tubes, and timing. Current methods of airway control are listed in Table 2 and are categorized as emergency or elective. It is always assumed that basic life support techniques will be in place before this hierarchic scheme for airway control is used. Unfortunately, hypoxemia continues to be a factor in preventable trauma deaths. There is much to be done in the future to further improve airway management in injured patients. There is an immediate need to assess methods of airway control in the pre-hospital phase using a randomized clinical trial. The ideal tube for cricothyroidotomy, tracheostomy, or endotracheal intubation remains to be designed. There is a need for further multicenter trials on the timing of tracheostomy in the critical care unit. The role of differential ventilators in the management of unilateral pulmonary parenchymal injury requires clinical validation. Intravascular membrane oxygenators have been proposed in advanced pulmonary insufficiency in a ventilated patient. Thus, while many important strides have been made in airway management following trauma, there remain great challenges in addressing the persistent problem of systemic hypoxemia after multiple injuries.


Complications of interlocking nailing for lower leg fractures: a 3-year follow up of 102 cases. Of the 109 patients treated by interlocking nailing for lower leg fractures between 1985 and 1990 at the A.ö.KH Schwaz and the LKH Bad Ischl, Austria, 92 underwent follow-up examination. Data were analyzed using a personal computer. Special attention was paid to fracture pattern, level, complications, and length of sick leave. Compared with a previous study, an increasing number of compound fracture patterns were evaluated. Except for 14 misalignments and two late infections after new injuries, no other serious complications were detected. Interlocking nailing can be highly recommended even for open fractures up to the second degree at any level from the second fifth to the fourth fifth of the tibia.


Intestinal infarction after nonabdominal trauma; association with cerebral trauma. Nonocclusive bowel infarction in nonabdominal trauma has been ascribed to periods of hypotension. However, to our knowledge only 17 cases have been reported, and hypotension was not always found. We studied the frequency and possible causes of intestinal infarction in all patients treated at our traumatologic intensive care unit from 1977 through 1986 (n = 2350). Intestinal infarction was diagnosed at the time of surgery or autopsy; patients with pre-existing vascular disease were excluded. We found 12 patients (incidence: 0.5%) of age 45 +/- 20 years (mean +/- SD). All had severe cerebral trauma [Head and Neck Abbreviated Injury Scale (AIS) score: 4-5, admission Glasgow Coma Scale (GCS) score: 6.5 +/- 3.8]. Eight patients suffered from additional injuries. The Injury Severity Score (ISS) was 27 +/- 7. All patients received ventilator assistance continuously before the diagnosis of intestinal infarction or death. The leading symptom of intestinal infarction was sepsis and multiple organ failure with abdominal distention. Five patients with favorable cerebral prognosis underwent surgery: one survived with good cerebral and gastrointestinal recovery. Four patients did not have surgery because of a poor cerebral prognosis. Three patients died of their cerebral trauma before intestinal infarction was clinically manifested. The data show that early diagnosis in ventilated patients with head injuries is extremely difficult because of the heterogenicity of this group of patients, the low frequency of the complication, and the complexity of the clinical picture. Although patients inevitably were exposed to several agents or situations associated with intestinal infarction, the ubiquitous causes were dehydration and diuretic therapy.


Computed tomographic evaluation to exclude traumatic aortic disruption. Traumatic aortic disruption from blunt trauma remains a lethal injury. The role of computed tomographic (CT) scanning in the diagnosis of traumatic aortic disruption (TAD) has been debated and varying results have been reported. We reviewed our experience with 133 consecutive cases of blunt trauma with abnormal findings on chest x-ray films of sufficient concern to require further evaluation for TAD. Of the 105 patients who underwent CT scanning as the initial evaluation, 11 (10%) required aortography (Ao) for diagnosis; seven had TAD. Twenty-eight patients with highly suggestive signs of TAD underwent Ao as the initial diagnostic test; five had TAD. Ten of the 12 patients (83%) undergoing surgical repair had good results; one died of exsanguination at surgery and the other suffered a profound neurologic injury. Follow-up by phone or chart review at 6 months to more than 5 years after injury revealed no late mortalities from unrecognized TAD. We conclude that high quality CT evaluation of patients with worrisome chest x-ray films following blunt trauma can be used to exclude TAD in the majority of cases. Aortography is reserved for cases in which there is a high clinical suspicion of TAD and for those patients in whom TAD cannot be confidently excluded by CT scanning.


Seatbelt injuries in children.

Seatbelt injuries in children. Twelve cases of Chance-type flexion-distraction injuries in children less than 16 years old were reviewed. Patients were evaluated in terms of initial treatment regimen, subsequent modifications, and ultimate outcome. Follow-up ranged from 6 months to 9 years. Seven patients with a significant ligamentous component to their injury were initially treated, for various reasons, in a brace. All patients responding to brace treatment had an initial kyphotic deformity of less than 20 degrees and a maximum measured deformity of less than 25 degrees. In patients in whom brace treatment failed, initial deformity was greater than 20 degrees in all cases. Kyphotic deformity progressed to greater than 30 degrees before surgical intervention in these four cases. Improved adherence to lap seatbelt precautions, while of great benefit in reducing motor vehicle-related morbidity and mortality, has simultaneously increased the likelihood of flexion-distraction lumbar spine injuries. Our results suggest that an approach to treatment designed specifically for children is appropriate.


Head and face injuries in bicyclists--with special reference to possible effects of helmet use. Fatal and nonfatal head and face injuries to unhelmeted bicyclists were analyzed to assess the injury-reducing potential of bicycle helmet use. Of the fatally injured, 64% (median age, 55 years) had fatal head and face injuries compared with 38% (median age, 18 years) with head and face injuries in the nonfatal injury group. The fatally injured often had multiple impact points, mostly to the occipital and temporal regions. Brain contusions, most often to the frontal and temporal lobes, were the most common cause of fatal injury, followed by subdural hematomas. In the nonfatal injury group abrasions/lacerations were most common type of injury, followed by cerebral concussions/contusions and superficial contusions. If all types of injuries to bicyclists are taken into account a helmet might have had an injury-reducing effect in two of every five fatal cases and in one of every five nonfatal cases. To increase the helmet use among bicyclists, a law, as in Australia, would be an excellent instrument.


Air bag injuries and occupant protection. Analysis of the investigations of crashes involving automobiles equipped with air bags verifies the estimations of the lifesaving and injury reduction benefits of this supplemental restraint system. Cases of air bag-associated injuries, primarily erythema, abrasions, and contusions of the lower face and anterior throat-upper chest, are identified as those most often observed. Corneal-scleral injuries were infrequently noted but are rarely found in crashes involving air bag deployments.


Severity and outcome of intracranial lesions in pedestrians injured by motor vehicles. To evaluate the type and severity of intracranial lesions and the prognosis after closed head trauma in pedestrians injured by motor vehicles, we reviewed the cases of 225 consecutive patients who suffered major head injuries in collisions with motor vehicles. Patients in this series were comatose, had intracranial hematomas requiring surgical removal, or both. The initial Glasgow Coma Scale (GCS) score was 9-15 in 24% of patients, 6-8 in 32%, and 3-5 in 43%. Intracranial hypertension occurred in 40%. Diagnostic studies showed subdural hematomas in 45% of patients, epidural hematomas in 8%, intracerebral hematomas in 10%, and cerebral contusions in 9%. Clinically significant mass lesions were evacuated, and intracranial pressure was monitored and treated aggressively if elevated. After 6 months, 51% of the patients had died, 13% were vegetative or severely disabled, and 35% had a good outcome or moderate disability. These major head injuries in pedestrians struck by motor vehicles were usually severe, included a high incidence of intracranial hematomas and increased intracranial pressure, and frequently had poor outcomes.


Technical note--trauma team activation: the sequential light panel. A progressive color-coded light activation panel is described that enhances in-hospital activation of the trauma team. This communication system creates a network among the resuscitation suite of the emergency department, the operating room, the anesthesiology department, and the surgery department.


Conservative management of a pulmonary artery bullet embolism: case report and review of the literature. A case of pulmonary artery bullet embolism managed by observation with no complications at 9-month follow-up prompted a review of the literature. We found a total of 32 cases reported since 1966, with no deaths. Fourteen of the patients were managed by observation and five patients were followed with no resulting complications noted. Conservative management of selected cases of pulmonary artery bullet emboli may be warranted in light of the risks of extraction. These cases should continue to be reported with follow-up.


Spontaneous endobronchial erosion and expectoration of a retained intrathoracic bullet: case report. In all four previously reported cases of endobronchial erosion from retained intrathoracic foreign objects, the object eventually required surgical removal. We report the case of a patient with a bullet in the left hemithorax who developed bronchial erosion and hemoptysis 3 months after the injury, with subsequent expectoration of the bullet. Although most foreign bodies within the thorax pose no special problems, migration of the object or the development of symptoms warrants investigation and possibly subsequent surgical removal of the object.


Iliofemoral venous thrombosis following fascial excision of a deep burn of the lower extremity: case report. Burned patients with deep venous thrombosis present a particularly perplexing challenge. They frequently require central venous catheters. Their altered skin integrity does not permit correlation with the typical changes described by the classic terminology for thrombophlebitis or its most severe forms, phlegmasia cerulea dolens or phlegmasia alba dolens. They are at risk of exsanguination or massive graft loss with lytic therapy or anticoagulation. Venous thrombectomy may be a necessary limb-saving surgical option.


Successful replantation of a bitten-off vermilion of the lower lip by microvascular anastomosis: case report. A successful case of lower lip vermilion replantation is presented where there was lack of a suitable vein for drainage after arterial flow was re-established. The venous stasis was overcome by the "chemical leech," intra-replant subcutaneous heparin injection at intervals 9 days postoperatively. The result is excellent both aesthetically and functionally.


Vascular injury from external fixation: case reports. The incidence of vascular injury from external fixation of fractures was studied retrospectively in two surgical departments during the period 1985-1990. A total of 1231 fractures of the lower limb were treated. External fixation was used in the initial stabilization of 28 femoral and 93 tibial fractures. In this series of 121 fractures four iatrogenic vascular injuries were seen: two arterial thromboses with distal ischemia and two incidents of the formation of a false aneurysm with bleeding along a pin. The diagnosis was made by angiography. Surgical intervention was necessary in all four cases. In one patient the injury resulted in amputation of the distal portion of the foot.


Dislocation of the carpal scaphoid associated with median nerve compression: case report. Dislocation of the carpal scaphoid is a rare injury. A case of delayed diagnosis of scaphoid dislocation necessitating late treatment is described. The scaphoid was displaced anteromedially, causing compression of the median nerve in the carpal canal. Treatment consisted of carpal tunnel decompression and scapho-trapezium trapezoid fusion. Useful wrist motion without significant pain was restored.


Free vascularized joint transfers in acute complex hand injuries: case reports. The loss of function of the metacarpophalangeal joint is a significant disability. Simultaneous reconstruction of the soft tissue, extensor mechanism, joint, and flexor tendon in a complex hand injury is difficult and challenging. Free vascularized autogenous toe joint transplantation is a useful technique that provides not only joint replacement but also the soft tissue, extensor mechanism, and flexor tendon in more severe complex hand injuries. Two patients underwent immediate, free vascularized metatarsophalangeal joint transfer of the second toe to replace the long and ring finger metacarpophalangeal joint in acute complex hand injuries. The follow-up results at 16 months and 8 months postoperatively are presented.


Rectosigmoid ischemia following blunt abdominal trauma in a patient treated with radiation therapy: case report. Ionizing radiation, frequently used to treat cancer, is known to injure skin and blood vessels and to deleteriously affect wound healing. We present the case of a patient whose previous radiation treatment predisposed him to colonic ischemia following blunt abdominal trauma.


Blunt myocardial disruption: report of an unusual case and literature review. Blunt cardiac injury is frequently noted among trauma patients. They may demonstrate few signs and symptoms or may be in profound shock. A unique case of left ventricular disruption in a young soldier who sustained blunt torso trauma is reported. A paucity of clinical findings led to a delay in diagnosis. He ultimately underwent successful repair 12 days after injury.


Seatbelt injury to the common iliac artery: report of two cases and review of the literature. Blunt trauma to the common iliac artery is rather rare. Moreover, seatbelt injuries to the common iliac artery have not yet been reported. This article presents two cases of seatbelt injury involving the common iliac artery. A deceleration-type mechanism is suggested as the primary cause of injury, resulting in the production of an intimal flap. The diagnosis of such an injury is based on clinical suspicion, a change of pulse, or lower limb ischemia. On arteriotomy the damage is greater than seen on external examination. Once diagnosed prompt treatment should follow to prevent loss of life or limb. The signs, symptoms, and modalities of treatment are reported, as well as a review of the literature.


Experimental inoculation of three arboviruses in black-bellied whistling ducks (Dendrocygna autumnalis). Wild-caught, immature black-bellied whistling ducks (Dendrocygna autumnalis) were inoculated with eastern equine encephalitis (EEE), St. Louis encephalitis (SLE), or western equine encephalitis (WEE) virus. Susceptibility, duration and titer of viremia, and antibody response to these arboviruses were determined. Birds from all inoculated groups became viremic. Higher virus titers occurred in the EEE group but overall mean titers were not significantly different among experimental groups. All birds inoculated with EEE and SLE viruses developed antibodies, and six of seven ducks receiving WEE virus were seropositive. All seropositive ducks had antibodies for at least 59 days, when the study was terminated. The EEE group had significantly more seropositive ducks during more days than the WEE and SLE groups. Geometric mean antibody titers were significantly smaller in the WEE group when compared to the EEE and SLE groups. Control ducks did not develop viremia or antibodies. Gross and histopathologic lesions compatible with viral encephalitis were absent in all of nine ducks necropsied. Black-bellied whistling ducks can develop low and short-term levels of viremia sufficient to infect mosquitoes, but probably cannot contribute significantly to the transmission of EEE and SLE. They may serve as good indicators of virus activity.