BHRF1, the Epstein-Barr virus gene with homology to Bc12, is dispensable for B-lymphocyte transformation and virus replication

The Epstein-Barr virus (EBV) BHRF1 open reading frame is abundantly expressed early in the lytic replication cycle. BHRF1 is also transiently expressed in some latently infected cell lines in the absence of expression of other lytic cycle proteins. BHRF1 shares distant, but significant, colinear primary amino acid sequence homology to Bc12, a cellular gene strongly implicated in the evolution of follicular lymphoma. The experiments reported here used a molecular genetic approach to examine the role of BHRF1 in EBV infection. Isogenic EBV recombinants having either wild-type BHRF1 or a null mutation due to a translational stop signal in place of the 24th BHRF1 codon were used to infect primary B lymphocytes. The BHRF1 mutant recombinants did not differ from the wild type in their ability to infect and transform the growth of primary B lymphocytes, to replicate in the resultant lymphoblastoid cell lines, or to initiate a second round of primary cell transformation. Deletion of the entire BHRF1 open reading frame did not destroy the ability of the mutant virus to maintain cell growth transformation. The significance of these findings with regard to the role of BHRF1 in EBV infection is discussed.

Intrathecal narcotics for relief of pain from head and neck cancer

We describe our experience with nine patients with head and neck pain of malignant origin who were treated with continuous low-dose intrathecal morphine via a lumbar catheter and implantable subcutaneous drug delivery pump. All patients had failed prior attempts at oral narcotic pain control due to either poor pain control or intolerable side effects. Using a visual analogue scale where the most severe pain is rated as 10 and no pain is rated as 0, the mean visual analogue scale was reduced from 7.6/10 (range, 5 to 10/10) before implantation to 1.9/10, 2.0/10, and 0.5/10 at 1 week, 1 month, and 2 months after implantation, respectively. Complications were acceptable. We conclude that intrathecal administration of morphine is a safe and effective means of pain control. This method deserves serious consideration in patients with intractable pain secondary to head and neck malignancy.

An Epstein-Barr virus nuclear protein 2 domain essential for transformation is a direct transcriptional activator

Epstein-Barr virus nuclear protein 2 (EBNA-2) increases mRNA levels of specific viral and cellular genes through direct or indirect effects on upstream regulatory elements. The EBNA-2 domains essential for these effects have been partially defined and correlate with domains important for B-cell growth transformation. To determine whether EBNA-2 has a direct transcriptional activating domain, gene fusions between the DNA-binding domain of GAL4 and EBNA-2 were tested in CHO and B-lymphoma cells for the ability to activate transcription from target plasmids containing GAL4 recognition sites upstream of an adenovirus or murine mammary tumor virus promoter. In B-lymphoma cells, a 37-amino-acid EBNA-2 domain previously identified to be essential for transformation was nearly as strong a transcriptional activator as the activating domain of herpes simplex virus trans-inducing factor VP16. A quadradecapeptide had about 25% of the activating activity of the longer peptide. This first evidence that EBNA-2 directly activates transcription should facilitate the identification of nuclear factors with which EBNA-2 interacts in transactivation and transformation.

Ex Situ Conservation of Plant Genetic Resources: Global Development and Environmental Concerns

Conservation of plant genetic resources is achieved by protection of populations in nature (in situ) or by preservation of samples in gene banks (ex situ). The latter are essential for users of germplasm who need ready access. Ex situ conservation also acts as a back-up for certain segments of diversity that might otherwise be lost in nature and in human-dominated ecosystems. The two methods are complementary, yet better understanding of this interrelation and the role of ex situ conservation in global environmental considerations is needed. Inclusion of ex situ conservation efforts within current environmental policies conserving global diversity would focus greater international attention on the safeguarding of these efforts.

Epstein-Barr virus nuclear protein 2 mutations define essential domains for transformation and transactivation

Epstein-Barr virus (EBV) nuclear protein 2 (EBNA-2) is essential for B-lymphocyte growth transformation. EBNA-2 transactivates expression of the EBV latent membrane protein (LMP-1) and also transactivates expression of the B-lymphocyte proteins CD21 and CD23. In order to analyze the functional domains of EBNA-2, we constructed 11 linker-insertion and 15 deletion mutations. Each of the mutant EBNA-2 proteins localized to the nucleus, and each was expressed at levels similar to wild-type EBNA-2. Deletion of both EBNA-2 basic domains was required to prevent nuclear localization, indicating that either is sufficient for nuclear translocation. The mutant EBNA-2 genes were assayed for lymphocyte transformation after recombination with the EBNA-2-deleted P3HR-1 EBV genome and for LMP-1 transactivation following transfection into P3HR-1-infected B-lymphoma cells. Cell lines transformed by recombinant EBV carrying EBNA-2 mutations were assayed for growth properties and LMP-1, CD21, and CD23 expression. The mutational analysis indicates that at least four separate EBNA-2 domains are essential for lymphocyte transformation. Two other domains are necessary for the full transforming phenotype. Two deletion and eight linker-insertion mutations did not reduce transforming activity. Mutations which diminish or abolish lymphocyte transformation also diminish or abolish LMP-1 transactivation, respectively. Cells transformed by recombinant EBV carrying EBNA-2 genes with diminished or normal transforming activity all expressed high levels of LMP-1, CD23, and CD21. These findings suggest that transactivation of these viral and cellular genes by EBNA-2 plays a critical role in lymphocyte transformation by EBV. Furthermore, these results indicate that the transformation and transactivation functions of EBNA-2 may not be separable.

Epstein-Barr virus lymphoproliferative disease associated with acquired immunodeficiency

Epstein-Barr virus (EBV) lymphoproliferative disease is seen in patients with both congenital and acquired immunodeficiencies. Lymphoproliferative disease has been reported in 1 to 3% of renal transplant recipients. Most patients presented with solid tumor masses, rather than an infectious mononucleosis-like syndrome. About one third of cases had involvement of the renal allograft with tumor; the small intestine or central nervous system was also frequently affected. About half of the patients survived. The most frequent therapy used for survivors was decreasing the dose of immunosuppressive therapy and surgical resection of lymphoproliferative lesions. Compared with fatal cases, survivors more often had evidence of active EBV infection (primary or reactivated), received cyclosporine as the major immunosuppressive agent, had polyclonal lesions, and had B-cell hyperplasia rather than lymphoma. Lymphoproliferative disease has been described in 5 to 13% of heart transplant recipients. In our review, the cardiac allograft was not involved by disease in any patient; however, the lungs were involved in more than half of the cases. The soft tissues were frequent sites of lymphoproliferative disease. All patients had lymphoma or immunoblastic sarcoma on pathology and all had monoclonal lesions. While only 8% of patients survived, about half died from causes unrelated to lymphoproliferative disease. EBV lymphoproliferative disease has been reported in 9% of heart-lung transplant recipients. Most of the patients presented with pulmonary symptoms and the pulmonary allograft was involved in 80% of cases. The large and small intestine were frequently affected. About 60% of patients survived; survivors were treated with acyclovir and decreases in the dose of immunosuppressive drugs. Lymphoproliferative disease has been described in 2% of liver transplant recipients. In our review, the hepatic allograft was involved in one third of cases; the tonsils, kidneys, and small intestine were frequently affected. Half of the patients survived; survivors were most often treated with reduction in immunosuppressive therapy and surgical resection of lesions. Compared with fatal cases, survivors had fewer organs involved and fewer monoclonal lesions. Lymphoproliferative disease has been reported in 1 to 2% of bone marrow transplant recipients. Use of T-cell depleted bone marrow and infusion of anti-T-cell antibodies to prevent graft-versus-host disease increased the risk of EBV lymphoproliferative disease. In our review, the bone marrow was involved by lymphoproliferative disease in one third of cases; the liver, spleen, kidney, and lungs were frequently affected. About 16% of patients survived; 2 survivors were treated with infusions of monoclonal anti-B-cell antibodies and 1 received interferon alpha.(ABSTRACT TRUNCATED AT 400 WORDS)

Inhibition of endogenous superoxide dismutase with diethyldithiocarbamate in acute island skin flaps

Oxygen free radicals have been implicated in postischemic tissue damage in a variety of experimental models including the island skin flap. Previous studies have demonstrated that supplementing animals with exogenous superoxide dismutase (SOD), a free radical scavenger, improves tissue survival in island flaps. No studies to our knowledge have attempted to inhibit endogenous SOD in a skin flap model. In this experiment 20 control rats demonstrated a 12.00% flap necrosis 7 days after a modified ventral island skin flap was raised. A second group of 20 rats were supplemented with exogenous SOD (50,000 U/kg 30 minutes preoperatively and 12 hours postoperatively) and demonstrated a statistically significant decreased flap necrosis of 5.28%. A third group of 20 rats received diethyldithiocarbamate (DDC, 0.5 gm/kg 12 hours preoperatively), an agent previously shown to inhibit SOD, and demonstrated a statistically significant increased flap necrosis of 19.77%. In a final group of 20 rats the effect of DDC was overcome by supplementation with exogenous SOD, obtaining a flap necrosis of 8.35%. Our results add further support to the importance of SOD and oxygen free radicals in postischemic tissue damage by demonstrating increased tissue necrosis with inhibition of endogenous SOD. This suggests that there is a baseline degree of SOD activity in ischemic areas working to preserve tissue. It appears that the copper-containing species of SOD found primarily in the cytoplasm plays a pivotal role in preservation of postischemic tissue.

Epstein-Barr virus nuclear antigen 2 transactivates latent membrane protein LMP1

Several lines of evidence are compatible with the hypothesis that Epstein-Barr virus (EBV) nuclear antigen 2 (EBNA-2) or leader protein (EBNA-LP) affects expression of the EBV latent infection membrane protein LMP1. We now demonstrate the following. (i) Acute transfection and expression of EBNA-2 under control of simian virus 40 or Moloney murine leukemia virus promoters resulted in increased LMP1 expression in P3HR-1-infected Burkitt's lymphoma cells and the P3HR-1 or Daudi cell line. (ii) Transfection and expression of EBNA-LP alone had no effect on LMP1 expression and did not act synergistically with EBNA-2 to affect LMP1 expression. (iii) LMP1 expression in Daudi and P3HR-1-infected cells was controlled at the mRNA level, and EBNA-2 expression in Daudi cells increased LMP1 mRNA. (iv) No other EBV genes were required for EBNA-2 transactivation of LMP1 since cotransfection of recombinant EBNA-2 expression vectors and genomic LMP1 DNA fragments enhanced LMP1 expression in the EBV-negative B-lymphoma cell lines BJAB, Louckes, and BL30. (v) An EBNA-2-responsive element was found within the -512 to +40 LMP1 DNA since this DNA linked to a chloramphenicol acetyltransferase reporter gene was transactivated by cotransfection with an EBNA-2 expression vector. (vi) The EBV type 2 EBNA-2 transactivated LMP1 as well as the EBV type 1 EBNA-2. (vii) Two deletions within the EBNA-2 gene which rendered EBV transformation incompetent did not transactivate LMP1, whereas a transformation-competent EBNA-2 deletion mutant did transactivate LMP1. LMP1 is a potent effector of B-lymphocyte activation and can act synergistically with EBNA-2 to induce cellular CD23 gene expression. Thus, EBNA-2 transactivation of LMP1 amplifies the biological impact of EBNA-2 and underscores its central role in EBV-induced growth transformation.

The ventral 'L' island flap. A refined model for skin flap research

The rat has long been used as an experimental model for obtaining preliminary data in skin flap research. Unfortunately, there has been a great deal of inconsistency both in the experimental design of the skin flaps used in this animal model and in their inherent survival pattern. We have developed a ventral "L" flap based on clear anatomic landmarks that offers a number of advantages over previously described rat skin flaps including a more consistent survival pattern. This flap was elevated in 23 rats, resulting in an average necrosis of 16.7% +/- 7.6% 7 days postoperatively. Our article outlines the details of this flap's design and its use. The ventral L flap offers a refined tool for skin flap research in the rat animal model.

Endophthalmitis due to Mycobacterium avium in a patient with AIDS

A 27-year-old man with acquired immunodeficiency syndrome [AIDS] had endophthalmitis OS four years after a trabeculectomy was done. The patient had a history of disseminated infection with Mycobacterium avium. Examination showed an intact filtering bleb with inflammation and hypopyon formation in the anterior chamber OS. The M. avium was cultured from an anterior chamber paracentesis. The patient responded to treatment with gentamicin, cefazolin, and prednisolone. Infection with M. avium should be included in the differential diagnosis of endophthalmitis in patients with AIDS.

Epstein-Barr virus nuclear protein 2 is a key determinant of lymphocyte transformation

Epstein-Barr virus (EBV) efficiently transforms B lymphocytes to perpetual proliferation. The EBV laboratory strain P3HR-1 is transformation-incompetent and lacks a DNA segment that includes the EBV nuclear antigen 2 (EBNA-2) gene and a portion of the EBNA leader protein (EBNA-LP) gene. These two genes are expressed in transformed B lymphocytes. Recombinant transformation-competent EBVs were produced by transfecting P3HR-1-infected cells with a cosmid containing the DNA deleted in P3HR-1. Deletion of 105 nucleotides from the middle of the EBNA-2 gene had no discernible affect on transformation. Two larger EBNA-2 deletions abolished transformation but did not affect EBNA-2 nuclear localization. Two naturally occurring EBV variants (EBV types 1 and 2) differ extensively in their growth-transformation phenotype and in their EBNA-LP, EBNA-2, and EBNA-3A, -3B, and -3C genes. Recombinant P3HR-1 carrying EBV-1 EBNA-2 has many of the EBV-1 in vitro growth-transforming effects; recombinant P3HR-1, isogenic except for EBV-2 EBNA-2, has many of the EBV-2 growth-transforming effects including slow emergence of transformants, growth in tight clumps with few surrounding viable cells, and early sensitivity to dilution with fresh medium. Thus, EBNA-2 is an essential molecule in lymphocyte growth transformation by EBV and a major determinant of the differences between EBV-1 and EBV-2 in lymphocyte growth transformation.

Attenuation and cell culture adaptation of hepatitis A virus (HAV): a genetic analysis with HAV cDNA

RNA transcripts of hepatitis A virus (HAV) HM-175 cDNA from attenuated, cell culture-adapted HAV were infectious in cell culture. A full-length HAV cDNA from wild-type HAV (propagated in marmosets in vivo) was constructed. Chimeric cDNAs that contained portions of both wild-type and attenuated genomes were produced. Oligonucleotide-directed mutagenesis was used to engineer a point mutation into the VP1 gene of attenuated HAV cDNA, so that the sequence of this capsid protein would be identical to that of the wild-type virus. Transfection of monkey kidney cells with RNA transcripts from several of the chimeric cDNAs and from the mutagenized cDNA induced production of HAV. Comparison of the growth of attenuated, wild-type, chimeric, and mutant viruses in vitro indicated that the P2-P3 (nonstructural protein) region is important for cell culture adaptation of the virus; the 5' noncoding region may also contribute to adaptation, but to a lesser extent. Inoculation of marmosets with transfection-derived virus also suggested that the P2-P3 region plays an important role in attenuation of HAV HM-175.

Hepatitis A virus infection in a chimpanzee: duration of viremia and detection of virus in saliva and throat swabs

The pathogenesis of hepatitis A virus was studied by orally inoculating a chimpanzee with wild-type virus. The virus was initially detected in the animal's serum (day 14 after inoculation); then viral antigen was detected in the tonsils (day 16), virus in the saliva and throat swabs (day 18), and viral antigen in the liver (day 21). The animal was viremic for 2 w. While this study involved a single animal, the presence of hepatitis A virus in saliva and throat swabs suggests a possible oropharyngeal site for viral replication.

Measurement of interstitial tissue compliance in skin flaps

Investigators speculate about the role of tissue pressure in skin flap necrosis as increased tissue pressure has been demonstrated to stop capillary blood flow in other conditions, both clinically and experimentally. Unfortunately, interstitial tissue pressure is difficult to measure by conventional methods. This article describes a new practical technique that measures interstitial tissue compliance as a correlate of interstitial tissue pressure. The instrument and method are described in detail. Tissue compliance was measured in normal dorsal skin and in modified McFarlane's skin flap in Sprague-Dawley rats. The skin flaps were measured at three sites (proximal, middle, and distal) at 2, 12, and 18 hours of age. The mean difference between the normal skin and all skin flaps was statistically significant. Within the skin flaps, there was a trend toward increased pressure with increasing age of the flap and distance from the flap base. These trends are statistically significant by the analysis of variance test. The data from this study support the validity of the technique and the hypothesis that increased interstitial tissue pressure is present in skin flaps.

Identification of an immunodominant antigenic site involving the capsid protein VP3 of hepatitis A virus

Hepatitis A virus, an hepatotropic picornavirus, is a common cause of acute hepatitis in man for which there is no available vaccine. Competitive binding studies carried out in solid phase suggest that neutralizing monoclonal antibodies to hepatitis A virus recognize a limited number of epitopes on the capsid surface, although the polypeptide locations of these epitopes are not well defined. Neutralization-escape mutants, selected for resistance to monoclonal antibodies, demonstrate broad cross-resistance to other monoclonal antibodies. Sequencing of virion RNA from several of these mutants demonstrated that replacement of aspartic acid residue 70 of capsid protein VP3 (residue 3070) with histidine or alanine confers resistance to neutralization by monoclonal antibody K2-4F2 and prevents binding of this antibody and other antibodies with similar solid-phase competition profiles. These results indicate that residue 3070 contributes to an immunodominant antigenic site. Mutation at residue 102 of VP1 (residue 1102) confers partial resistance against antibody B5-B3 and several other antibodies but does not prevent antibody attachment. Both VP3 and VP1 sites align closely in the linear peptide sequences with sites of neutralization-escape mutations in poliovirus and human rhinovirus, suggesting conservation of structure among these diverse picornaviruses. However, because partial neutralization resistance to several monoclonal antibodies (2D2, 3E1, and B5-B3) was associated with mutation at either residue 3070 or residue 1102, these sites appear more closely related functionally in hepatitis A virus than in these other picornaviruses.

Sequence comparison of woodchuck hepatitis virus replicative forms shows conservation of the genome

The complete nucleotide sequence of virion DNA from two isolates of woodchuck hepatitis virus (WHV 7 and WHV 59) was determined along with the sequence of supercoiled DNA from one of those isolates (WHV 7). The sequences of the two WHV isolates were compared with the previously published sequences of two other isolates (WHV 1 and WHV 8). The range of nucleotide sequence variation of the four isolates (1 to 3.5%) was similar to those of HBVs of the same subtype (1.5 to 2%), but less than those of HBVs of different subtypes (8 to 10%). When amino acid sequences from the four WHV isolates were aligned, a consensus sequence could not be obtained at 13 sites. At 11 of 13 sites (7 in polymerase, 2 in presurface, 1 in surface, and 1 in the X region) the viruses could be grouped into pairs, so that WHV 1 and WHV 59 shared one amino acid and/or WHV 7 and WHV 8 shared a different amino acid. WHV 7 was passaged twice in woodchucks and supercoiled DNA was isolated. The nucleotide sequence of WHV 7 supercoiled DNA (derived from liver) was compared to that of WHV 7 virion DNA (derived from serum). Sequence comparison of virion and free supercoiled DNA from WHV 7 showed no nucleotide changes, except for a single nucleotide deletion thought to represent an error during molecular cloning or a defective viral genome. Thus, the nucleotide sequence of two different replicative forms of WHV DNA, separated by two in vivo passages, were virtually identical.

Oral cavity reconstruction using the free radial forearm flap

While a number of flaps are available that can "plug the hole" created by the resection of an oral cavity malignancy, the final functional and cosmetic result is often far from satisfactory. The ideal flap for this area should provide a one-stage, reliable reconstruction (regardless of previous surgery or irradiation) with the options of thin pliable skin and/or vascularized bone. Donor-site morbidity must be acceptable. In our experience, the free radial forearm flap best approaches these ideals. Unfortunately, it has received relatively little attention in the otolaryngology literature. The results of using 15 of these flaps to reconstruct 14 oral cavity defects are reported here. Despite the fact that most of the reconstructions were performed in older patients who had undergone irradiation (nine of 14) and previous surgical treatment (ten of 14), there were no flap failures. Hospital stays were short (less than two weeks), cosmetic results were good, and all but one patient had resumed oral intake by the time of hospital discharge. The specific applications and limitations of this flap are emphasized so that the reader can better understand its role in head and neck reconstructive surgery.

Hepatitis A virus cDNA and its RNA transcripts are infectious in cell culture

A full-length cDNA copy of an attenuated, cell culture-adapted hepatitis A virus (HAV HM-175/7 MK-5) genome was constructed in the PstI site of plasmid vector pBR322. Transfection of monkey kidney cells with this plasmid failed to induce the production of hepatitis A virus (HAV). The HAV cDNA was excised from pBR322 and inserted, without the oligo(dG) X oligo(dC) tails, into an RNA transcription vector to yield plasmid pHAV/7. Transfection of monkey kidney cells with pHAV/7 DNA induced HAV infection. Transfection with RNA transcripts produced in vitro from pHAV/7 yielded about 10-fold more HAV than did transfection with pHAV/7 DNA. Marmosets inoculated with transfection-derived virus developed anti-HAV antibodies and had liver enzyme patterns that closely resembled the liver enzyme patterns seen in animals inoculated with virus from a comparable level of cell culture passage. Infectious RNA transcripts from HAV cDNA should be useful for studying the molecular basis of cell culture adaptation and attenuation as well as for studying specific viral functions.

Extra-intestinal manifestations of salmonella infections

While salmonellosis is often considered to affect primarily the gastrointestinal tract, infection at other sites may occur, producing characteristic clinical syndromes. We reviewed cases from our institutions and the literature on focal manifestations of salmonella infections. In the past, most extra-intestinal salmonella infections were caused by S. choleraesuis; however, we found S. typhimurium to be the predominant serotype. The mortality rate for patients in our series was considerably lower than the rate described for focal infections in other reviews. This may in part be due to lower proportion of infections due to S. choleraesuis, improved microbiologic and diagnostic techniques, increased use of ampicillin, and improved surgical techniques. Salmonella endocarditis usually occurs in patients with preexisting heart disease. Unlike other salmonella infections, S. choleraesuis is the most frequent serotype. Salmonella endocarditis is often very destructive, with a fatality rate of 70%. Nonvalvular (mural) endocarditis occurs in one-fourth of patients and survival has not been reported. While antibiotic therapy should be tried initially, if response is not prompt the clinician should look for an associated site of infection (intra- or extra-cardiac abscess), which will often require surgery. Salmonella pericarditis often presents with cardiac or pulmonary symptoms, but typical signs of pericardial disease (pulsus paradoxus, friction rub) or characteristic electrocardiographic changes (low voltage, elevated ST segments) are uncommon. Early diagnosis, before infection involves other areas of the heart, is crucial for survival. In addition to antibiotic therapy, pericardiocentesis or pericardiectomy is required. Salmonella may infect the peripheral or visceral arteries, but the abdominal aorta is the most frequent site of vascular infection. Most patients are men over age 50 with preexisting atherosclerosis of the aorta who do not have a previous history of gastroenteritis. About one-fourth of patients have associated lumbar osteomyelitis. No patients have been reported to survive with medical therapy alone. Specific guidelines for surgical removal of infected aneurysms have been proposed and these (in addition to increased use of ampicillin) may be responsible for higher survival rates in recent years. Due to the high incidence of relapses, postoperative blood cultures should be done routinely. Arterial infection should be considered in any elderly patient with salmonella bacteremia especially with prolonged fever or bacteremia after an "adequate course" of antibiotic therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Complete nucleotide sequence of an attenuated hepatitis A virus: comparison with wild-type virus

The complete nucleotide sequence of an attenuated hepatitis A virus, HAV HM-175/7 MK-5, was determined from cloned cDNA. This virus was derived from wild-type HAV HM-175 after 32 passages in African green monkey kidney cells. The resultant cell culture-adapted virus is attenuated for chimpanzees. This virus was passaged an additional three times in monkey kidney cells to obtain sufficient virus for molecular cloning and was designated HM-175/7 MK-5. Three overlapping cDNA clones were obtained that together spanned the entire genome. Comparison of the nucleotide sequence of cDNA from wild-type virus (propagated in marmoset liver in vivo) with attenuated virus (grown in cell culture) showed 24 nucleotide changes distributed throughout the genome. Five base deletions occurred in the 5' noncoding region, and 12 of the 16 base substitutions in the coding region resulted in amino acid changes. Amino acid changes occurred in viral capsid proteins VP1 and VP2 and several of the nonstructural proteins. Thus, a small number of nucleotide changes are responsible for adaptation to cell culture and attenuation of HAV strain HM-175.

A predictive model for wound sepsis in oncologic surgery of the head and neck

A prospective analysis of patients undergoing surgical resection of squamous cell carcinoma of the upper aerodigestive tract was performed in order to identify the patients at risk of postoperative wound infection and to develop a model predictive of wound infection. Fifty-nine patients who underwent extirpative clean-contaminated procedures--all of whom received cefazolin as the sole chemoprophylactic agent, were studied over a 1-year period. Twenty-three variables were recorded for each patient in the study. The overall rate of wound infection was 25.4%. Univariate analysis indicated that three variables were significantly related to the likelihood of postoperative wound infection. These included tumor stage (P = 0.0180), nodal stage (P = 0.0062), and duration of surgery (P = 0.0151). The Biomedical Computer Program (BMDP), a logistic regression program specifically designed for a binary dependent variable (infection vs. no infection) based on independent variables that may be continuous or categorical, was used in development of a model predictive of wound infection. T-stage, N-stage, and the presence of concomitant disease made up the combination of factors found to be most predictive of infection in our study population. Considering "success" to be the development of infection if the probability was 75% or higher, and the absence of infection if the probability was less than 25%, the multiple regression analysis model demonstrated a predictive success rate of 74.6%. Our results indicate that the risk of infection in patients undergoing clean-contaminated oncologic surgery of the head and neck is greatest for patients who have advanced disease that requires prolonged surgery in the presence of concomitant diseases.(ABSTRACT TRUNCATED AT 250 WORDS)

Complete nucleotide sequence of wild-type hepatitis A virus: comparison with different strains of hepatitis A virus and other picornaviruses

The complete nucleotide sequence of wild-type hepatitis A virus (HAV) HM-175 was determined. The sequence was compared with that of a cell culture-adapted HAV strain (R. Najarian, D. Caput, W. Gee, S.J. Potter, A. Renard, J. Merryweather, G.V. Nest, and D. Dina, Proc. Natl. Acad. Sci. USA 82:2627-2631, 1985). Both strains have a genome length of 7,478 nucleotides followed by a poly(A) tail, and both encode a polyprotein of 2,227 amino acids. Sequence comparison showed 624 nucleotide differences (91.7% identity) but only 34 amino acid differences (98.5% identity). All of the dipeptide cleavage sites mapped in this study were conserved between the two strains. The sequences of these two HAV strains were compared with the partial sequences of three other HAV strains. Most amino acid differences were located in the capsid region, especially in VP1. Whereas changes in amino acids were localized to certain portions of the genome, nucleotide differences occurred randomly throughout the genome. The most extensive nucleotide homology between the strains was in the 5' noncoding region (96% identity for cell culture-adapted strains versus wild type; greater than 99% identity among cell culture-adapted strains). HAV proteins are less homologous with those of any other picornavirus than the latter proteins are when compared with each other. When the sequences of wild-type and cell culture-adapted HAV strains are compared, the nucleotide differences in the 5' noncoding region and the amino acid differences in the capsid region suggest areas that may contain markers for cell culture adaptation and for attenuation.

Streptokinase therapy of pulmonary emboli with heparin-associated thrombocytopenia

A 59-year-old man developed pulmonary emboli with heparin-associated thrombocytopenia. He was treated simultaneously with intravenous streptokinase and oral warfarin sodium. He responded with complete resolution of perfusion defects on lung scan and did not have any hemorrhagic or thrombotic problems. Although optimal therapy for patients with heparin-associated thrombocytopenia and thrombosis is unknown, fibrinolytic therapy may be useful despite thrombocytopenia, provided appropriate resources are available for careful patient monitoring and transfusion therapy.

Cytomegalovirus infection in the normal host

CMV mononucleosis often resembles EBV infectious mononucleosis; however, certain features of the history and physical may help to distinguish CMV from EBV. While CMV mononucleosis is usually self-limited, certain laboratory abnormalities may persist for months or years after the patient has recovered. Previous reports on CMV in the non-immunocompromised host have rarely described systemic complications. We have reviewed 10 cases of CMV with systemic manifestations at one institution over a 15-year period. These patients had prolonged fevers (often greater than three weeks) and the diagnosis was often unsuspected during the early part of the illness. While two patients required mechanical ventilation, all patients had self-limiting disease and survived. When CMV is suspected and diagnosed early in the course, numerous diagnostic (and potentially dangerous) tests can be avoided in a viral illness in which prolonged fever is common.

Chronic pancreatitis: long-term surgical results of pancreatic duct drainage, pancreatic resection, and near-total pancreatectomy and islet autotransplantation

Severe abdominal pain was the major indication for operation in 85 patients with chronic pancreatitis. Preoperative endoscopic retrograde cholangiopancreatography (50 patients) or intraoperative pancreatic ductograms (44 patients) demonstrated dilated or obstructed major pancreatic ducts in 50 patients (59%), nonvisualization of the distal duct in 10 patients (12%), and normal or small sized ducts in 34 patients (40%). Operative procedures, tailored according to duct morphology, included pancreatic duct drainage (46 patients), subtotal (40% to 80%) pancreatectomy (21 patients), near-total (85% to 95%) pancreatectomy alone (eight patients), and near-total or total pancreatectomy and intrahepatic islet autotransplantation (10 patients). Pancreatic duct drainage resulted in pain relief in 37/46 patients (80%) followed for 6 years. However, 20/46 patients (43%) had continued loss of pancreatic function after duct drainage as measured by the development of insulin-dependent diabetes (16 patients) or steatorrhea (seven patients). Seven years after subtotal pancreatectomy, pain relief was partial in 9/21 patients (43%) and complete in five patients (24%). A higher incidence of hypoglycemic or ketoacidotic complications was noted in patients treated by subtotal pancreatectomy (three patients, 14%) than by duct drainage (one patient, 2%). Near-total pancreatectomy was the most effective surgical procedure in relieving pain, but late sequelae in three patients (38%) included one hypoglycemic death and two ketoacidotic episodes. Five years after near-total pancreatectomy and islet autotransplantation, one patient remained permanently insulin independent; three patients were insulin independent for 4, 5, and 15 months, respectively, but subsequently developed nonketosis-prone diabetes (tested by insulin withdrawal) and require 15 to 30 U of insulin daily; three patients had immediate insulin requirements and currently need 20 to 30 U of insulin per day but are nonketosis prone; and two patients are ketosis prone and require 30 to 60 U of insulin daily. Our analysis suggests that 5-year survival of patients undergoing operation for chronic pancreatitis is similar after treatment by duct drainage, subtotal pancreatectomy, or near-total pancreatectomy, regardless of duct morphology. Five years after duct drainage or subtotal pancreatic resection, a high incidence of diabetes (59% and 48%) and/or continued pain (20%) and (35%) can be expected.(ABSTRACT TRUNCATED AT 400 WORDS)

Late appearance of skin rash in Rocky Mountain spotted fever

Late appearance of a skin rash in Rocky Mountain spotted fever is associated with a high mortality. Our patient's rash appeared 14 days after the onset of illness, during his recovery. In endemic areas one must rely on clinical clues other than rash to raise the suspicion of Rocky Mountain spotted fever. The combination of fever, headache, myalgias, marked left shift in the differential white blood cell count, severe thrombocytopenia, and hyponatremia all help to suggest the correct diagnosis early in the course of the illness.

Resolution of factor X deficiency in primary amyloidosis following splenectomy

A 57-year-old man with primary amyloidosis was initially seen with hematuria, cutaneous bleeding, and hepatosplenomegaly. Factor X was determined to be 10% to 16% of normal plasma values. Administration of vitamin K-dependent factor concentrate transiently improved in vitro clotting tests but did not alter the clinical course. Following a splenectomy, bleeding ceased and factor X levels returned to normal, remaining so despite discontinuation of factor concentrate infusion. Amyloid fibrils extracted from the patient's spleen were determined to be derived from lambda V1 light chains. The importance of splenectomy as an effective therapeutic modality is discussed.

Mandibular reconstruction: open reduction and internal fixation of mandibular fractures

Open reduction and internal fixation of mandibular fractures by intraosseous wiring in conjunction with intermaxillary fixation remains the mainstay of mandibular fracture treatment despite the availability of newer methods. The principles of treatment are reviewed, including indications for use of this technique and its advantages and disadvantages. Various surgical techniques are also reviewed and key points in their application emphasized.

Delivery of chemotherapeutic agents to the central nervous system

The blood-brain barrier may prevent passage of effective chemotherapeutic agents to the brain in patients with infections, malignancies, or inborn errors of metabolism. tetanus toxin might be modified and employed as a vehicle to deliver drugs or enzymes to the central nervous system.