DLA-DQA1 polymorphisms in dogs defined by sequence-specific oligonucleotide probes (SSOP)

Several recent studies have identified DNA sequences for alleles of the DLA-DQA1 locus in the dog. To date, 10 DQA1 alleles have been reported. No data exists on the frequencies of these alleles within the general dog population, nor is there any indication of whether alleles are breed specific. We have addressed this issue by establishing a molecular-based sequence-specific oligonucleotide probing (SSOP) method to identify all published DQA1 alleles and have used these methods to type a large number of dogs. Oligonucleotide probes were designed to detect all the polymorphic sites in exon 2. This allowed assignment at the allele level. Three hundred and thirty dogs were typed for DQA1. All but two of the published DQA1 alleles were identified in these animals. One new allele was identified, and confirmed by DNA cloning and sequencing. This typing method provides a powerful tool for generating data that will be essential for studies investigating the genetic relationships between different breeds.

Identification of further DLA-DRB1 and DQA1 alleles in the dog

Three novel DLA-DRB1 alleles and one novel DQA1 allele have been identified in a panel of 367 dogs. These were suggested by unusual reaction patterns found in sequence specific oligonucleotide probing (SSOP) data. Four new alleles were confirmed using DNA cloning and sequencing.

Mucormycosis: a case study

Throughout the history of mucormycosis, from the first case in humans reported in 1885 by Paltauf, through publication by Gregory et al of the first observation of rhino-orbital cerebral mucormycosis in 1943, to the report by Harris in 1955 of the first known survivor, little has changed in the diagnosis and outcome of this disease. Although mucormycosis of any form--cerebral, cutaneous, rhinocerebral, intestinal, or pulmonary--is still a rarity, it should be suspected in patients who are diabetic or immunocompromised. Administration of amphotericin B, surgical debridement of infected tissue, correction of the underlying cause, and use of adjunctive HBO therapy remain the standard treatments.

Mucormycosis: a case study

Throughout the history of mucormycosis, from the first case in humans reported in 1885 by Paltauf, through publication by Gregory et al of the first observation of rhino-orbital cerebral mucormycosis in 1943, to the report by Harris in 1955 of the first known survivor, little has changed in the diagnosis and outcome of this disease. Although mucormycosis of any form--cerebral, cutaneous, rhinocerebral, intestinal, or pulmonary--is still a rarity, it should be suspected in patients who are diabetic or immunocompromised. Administration of amphotericin B, surgical debridement of infected tissue, correction of the underlying cause, and use of adjunctive HBO therapy remain the standard treatments.

The distribution of exocrine glands in Lepeophtheirus salmonis and Caligus elongatus (Copepoda: Caligidae)

The morphology, function and distribution of exocrine glands of copepods have rarely been studied in detail and almost nothing is known about them in the sea lice species L. salmonis and C. elongatus. This study utilised a novel application of a light-microscopy staining technique to reveal a variety of glands m nauplius, copepodid, chalimus, preadult and adult stages. The stain, 3’,3-diaminobenzidine tetrahydrochloride (DAB), applied to fresh material, differentiated a population of exocrine glands and enabled a study of their distribution. The stain was successful in highlighting the ducts and pores associated with the larger glands. The locations of gland sub-populations were conserved in all life-stages, although glands in the swimming legs were found to be better represented in mobile and free-swimming stages i.e. copepodids, preadults and adults. Glands associated with the mouth-tube were also located. Other, non-glandular, peroxidase-positive regions were also highlighted by the stain. These regions were found mainly in preadult and adult stages where they formed characteristic bi-symmetrical patterns on the cuticle of the dorsal surface. A study of some calanoid copepods suggested that peroxidase-positive glands are a feature peculiar to caligid copepods. This staining technique has proven useful for elucidating the ontogeny of gland populations in caligids.

Activation and adoptive transfer of Epstein-Barr virus-specific cytotoxic T cells in solid organ transplant patients with posttransplant lymphoproliferative disease

The treatment of Epstein-Barr virus (EBV)-associated lymphoproliferative disease (PTLD) in EBV seronegative solid organ transplant recipients who acquire their EBV infection after engraftment poses a considerable challenge because of underlying immunosuppression that inhibits the virus-specific cytotoxic T cell (CTL) response in vivo. We have developed a protocol for activating autologous EBV-specific CTL lines from these patients and show their potential use for immunotherapy against PTLD in solid organ transplant patients. Peripheral blood mononuclear cells from a panel of solid organ transplant recipients with and without active PTLD were used to assess EBV-specific memory CTL responses. The activation protocol involved cocultivation of peripheral blood mononuclear cells with an autologous lymphoblastoid cell line under conditions that favored expansion of virus-specific CTL and hindered the proliferation of allospecific T cells. These CTL consistently showed (i) strong EBV-specificity, including reactivity through defined epitopes in spite of concurrent immunosuppressive therapy, and (ii) no alloreactivity toward donor alloantigens. More importantly, adoptive transfer of these autologous CTLs into a single patient with active PTLD was coincident with a very significant regression of the PTLD. These results demonstrate that a potent EBV-specific memory response can be expanded from solid organ recipients who have acquired their primary EBV infection under high levels of immunosuppressive therapy and that these T cells may have therapeutic potential against PTLD.

Interbreed variation of DLA-DRB1, DQA1 alleles and haplotypes in the dog

Although 36 DLA-DRB1 and 10 DLA-DQA1 allele sequences have been published to date, no data on individual allele frequencies exists, either for specific breeds or cross breeds, and the full extent of the polymorphism at each of these loci is still not known. We have used sequence-specific oligonucleotide probing (SSOP) to characterise a series of 367 dogs for their DRB1 and DQA1 alleles. These included individual animals from over 60 different breeds, with numbers per breed ranging from 1 to 39. DLA types were generated from 218 dogs for DRB1 and from 330 dogs for DQA1, while 181 dogs were characterised for both these loci. The frequency of individual DRB1 and DQA1 alleles showed considerable interbreed variation, e.g. 83% of West Highland White Terriers were DRB1*01 as opposed to 9% of Collies. No breed had >9 of the 22 DRB1 types defined in this study; several breeds had only two DRB1 types. DLA-DQA1 showed less variation in allele numbers per breed, but also showed considerable interbreed frequency variation. Haplotype analysis revealed over 44 different DRB1/DQA1 combinations. Of these, 25 were in a number of animals, and also in an animal that was homozygous for one or both of these loci. Some DRB1 alleles could be found in combination with several different DQA1 alleles, while others were only present in one haplotypic combination. DLA allele frequency data in normal dogs will be critical for disease association studies. It may also be possible to use haplotype data to establish the genetic relationships between different dog breeds.

A case of acute renal failure and compartment syndrome after an alcoholic binge

A 25 year old man presented with anuria and bilateral leg pain two days after an alcoholic binge. He subsequently developed rhabdomyolysis causing acute renal failure, with compartment syndrome of both lower legs. This required urgent dialysis and fasciotomy respectively within six hours of admission. He remained dialysis dependent for three weeks and only after four months was he able to weight bear on both legs. Alcohol is a leading cause of rhabdomyolysis. Early recognition and prompt treatment is essential to prevent serious complications.

Obturator neuropathy. An anatomic perspective

Entrapment of the anterior division of the obturator nerve is a recently described cause of medial groin pain. This anatomic study examines the extrapelvic course of the nerve and related fascia in the adductor region to provide an anatomic basis for the syndrome and to aid in surgical treatment. Twelve anatomic specimen limbs were dissected to document the extrapelvic course of the obturator nerve, the myofascial arrangement, and the vasculature. A thirteenth limb was prepared with intraarterial glycerin to examine the vessels in more detail. A distinct fascial plane was found deep to the adductor longus and pectineus overlying the anterior division of the obturator nerve. The arterial supply to the adductor muscles is related intimately to the nerve and its branches, with associated local thickening of the fascial connective tissue. The relationship between the nerve, vessels, and fascia appears sufficient to result in an entrapment syndrome. The anatomic findings from this series will help plan the surgical treatment of this condition.

Sterilization of contaminated bone-tendon autografts using 10% povidone-iodine solution

This study evaluates methods of sterilizing contaminated bone-tendon autografts using 10% povidone-iodine solution. Sterile grafts were prepared from human cadavers. Grafts were immersed in a suspension of either Staphylococcus aureus or Pseudomonas aeruginosa, and three sets of sterilization experiments were performed in 10% povidone-iodine for 30 minutes: one each with S. aureus and P. aeruginosa by static soaking and a third with S. aureus by serial washing with agitation. Of grafts inoculated with S. aureus, six of six grew the test organism after soaking at room temperature, as did five of six after soaking at 36 degrees C and also eight of nine after washing with agitation. Of grafts inoculated with P. aeruginosa, five of six grew the test strain after soaking at room temperature, as did six of six after soaking at 36 degrees C. Thirty minutes of exposure to aqueous 10% povidone-iodine does not adequately sterilize an inoculated graft.

Nerve entrapment syndromes as a cause of pain in the hip, groin and buttock

In sports medicine, chronic hip, groin and buttock pain is a common diagnostic problem. Because of the complex anatomy of this region and the many potential neurological causes for pain, few sports clinicians have a detailed understanding of this problem. This paper discusses the clinical aspects of nerve entrapment syndromes related to sport and takes a regional approach in order to provide a diagnostic framework for the general sports physician. The various neurological syndromes are discussed and the surgical management elaborated in detail. For some specific conditions, such as the so-called 'piriformis syndrome', the pathophysiological understanding has changed since the early descriptions and now this particular diagnosis is often ascribed to almost any cause of buttock and/or hamstring symptoms. We discuss the nature of the origin of local symptoms and note that the often described symptoms are more likely due to compression of structures other then the sciatic nerve. Furthermore, the role of piriformis hypertrophy or anatomical nerve variations in the genesis of this syndrome must be questioned. We suggest renaming this the 'deep gluteal syndrome' to account for all of the observed phenomena. As sports medicine continues to develop a scientific basis, the role of nerve entrapments as the basis for chronic symptomatology is undergoing a new understanding and clinicians need to be aware of the diagnostic possibilities and be able to advise patients accordingly on the basis of scientific fact not anecdotal fiction.

Effect of beta-glucan from oats and yeast on serum lipids

Heart disease is the leading cause of death in the U.S. One way to reduce the risk of developing the disease is to lower serum cholesterol levels by making dietary changes. In addition to reducing intake of total fat, saturated fat, and dietary cholesterol, serum cholesterol can be further reduced by added fiber, especially from sources rich in beta-glucan. In this review, two sources of beta-glucan are described; one source is oats and the other yeast. Their chemical structures and physical properties are compared, and their effect on serum lipid levels is described. Oat beta-glucans are found in various breakfast cereals and snacks. Usually, several servings of these products are required to meet the Food and Drug Administration's claim of reducing the risk of heart disease. The yeast-derived fiber is a more concentrated source of beta-glucan than the oat product. It is currently being tested in a wide variety of food products.

DLA-DRB1 polymorphisms in dogs defined by sequence-specific oligonucleotide probes (SSOP)

To date, DNA sequences for 29 dog DLA-DRB1 alleles have been reported. However, no data exists on the frequencies of these alleles within the general dog population, nor is there any indication of whether there is interbreed variation of allele distribution. We have addressed this by establishing a molecular based sequence-specific oligonucleotide probing (SSOP) method to identify all of the known broad DRB1 types and we have used this to type a random panel of dogs. A series of oligonucleotide probes were designed to detect known polymorphisms in the three DRB1 hypervariable regions, together with two distinctive motifs in other regions of exon 2. This set of probes enabled us to assign broad DRB1 types. Two hundred and eighteen dogs were SSOP typed for DRB1. All but 4 of the published DLA-DRB1 alleles were identified in these animals. Interbreed variation in both allele distributions and allele frequencies were observed, which may be useful in the study of genetic variation between breeds. This variation also has implications for the selection of control groups for studies aimed at identifying MHC associations with disease susceptibility in the dog.

[Antineutrophil cytoplasmic antibodies in 2 patients with Wegener's granulomatosis]

We describe two patients with diffuse alveolar hemorrhage and Wegener s Granulomatosis. In both cases, ANCA were demonstrated. We discuss the profit about ANCA s in the diagnosis and management the systemic vasculitis.

Blood-brain barrier disruption for the treatment of malignant brain tumors: The National Program

Chemotherapy delivery for the treatment of malignant brain tumors is markedly enhanced when given in conjunction with osmotic opening of the blood-brain barrier. Osmotic opening or disruption of the blood-brain barrier is achieved while the patient is under general anesthesia, by the infusion of mannitol into the internal carotid or vertebral artery circulation. The mannitol infusion is followed by administration of intraarterial chemotherapy. A National Blood-Brain Barrier Program now exists and includes six universities. Within the National Program over 4200 blood-brain barrier disruption procedures have been performed in over 400 patients. Patients with primary central nervous system (CNS) lymphoma, glioma, primitive neuroectodermal tumor (PNET), germ cell and metastatic cancer are eligible for treatment. Results in patients with primary CNS lymphoma, recently reported in the Cancer Journal, include the first example of a durable response in a primary brain tumor without loss of cognitive function and without use of radiotherapy. Results with PNET and germ cell tumors are also very encouraging. Advanced practice nurses coordinate the care of blood-brain barrier disruption patients. Care includes patients selection, education, close neurological observation, maintenance of fluid and electrolyte balance and managing effects of high-dose chemotherapy. Both acute and long-term medical and psychological follow-up are an essential component of the program, as well as patient and family support.

Altered expression of troponin T isoforms in mild left ventricular hypertrophy in the rabbit

Alterations in troponin T (TnT) isoforms have been reported in severe human and experimental heart failure (HF), and may play a role in the depressed myofibrillar ATPase activity observed in this condition. It is unclear whether these alterations reflect very severe hemodynamic derangement or are a component of mild hypertrophic stress. Therefore, we studied the expression of TnT isoforms (SDS-PAGE, Western blots), myosin isoforms, myofibrillar ATPase activity, and left ventricular (LV) mechanoenergetics (rbc perfused, isovolumically contracting isolated heart) in a rabbit model of mild hypertrophy (LVH) due to gradual hypertension caused by 12 weeks of cellophane wrap of the kidneys (n=12). LV/body weight ratio increased by 28% in LVH compared to shams (P<0.001); no animals had evidence of HF. In LVH, the percentage of TnT2 was modestly but significantly increased compared to shams [6.2+/-1.9 (+/-S.D. ) v 3.7+/-1.0%, P<0.05], mainly as a consequence of a parallel decrease in TnT4 (P=0.07). Sham hearts ranged from 75-100% V3 isomyosin, whereas all LVH hearts had 100% of the V3 form. There were no significant differences in myofibrillar ATPase activity or mechanical variables, including contraction and relaxation rates. The slope of the VO2-pressure-volume-area relation (a measure of the energy conversion efficiency of the contractile machinery) was also unchanged. We conclude that in the rabbit, shifts in TnT isoforms toward a more "fetal" pattern occur during mild LVH and, therefore, are likely to be a general feature of the response to hemodynamic stress, rather than a phenomenon confined to end-stage disease. These modest shifts are not associated with major alterations in LV myofibrillar ATPase activity or mechanoenergetics.

S. cerevisiae and sulfur: a unique way to deal with the environment

Saccharomyces cerevisiae is by far the best-studied unicellular eukaryote. Although yeast cells are very similar to higher eukaryotes in many respects, there is striking evidence that S. cerevisiae is not a perfect model for a eukaryotic cell (cf. 1). Here we report that yeast proteins contain a significantly lower amount of cysteine residues compared to other eukaryotes. Explanations for this phenomenon could not be found in the sulfur metabolism of yeast, which showed no major differences from other organisms (2-4). However, previous examinations could link a defect in sulfate uptake of S. cerevisiae to an increased resistance against toxic substances like selenate and chromate in the environment, which share the same permeases (5-7). This environmental problem might have caused S. cerevisiae to down-regulate its sulfate uptake and therefore lead to a lower amount of available sulfur in the cell, making it necessary to replace all dispensable sulfur amino acids in proteins. We show in two examples that S. cerevisiae proteins contain only such cysteine residues that are structurally or functionally needed. Therefore, we conclude that S. cerevisiae has solved a widespread environmental problem in a specific way which might be unique among eukaryotes.

Prevention of hepatitis A and B

The vaccine preventable hepatitides, hepatitis A and hepatitis B, cause a great burden of illness in both developing and industrialized nations. There is increased community awareness of the problems of viral hepatitis, and it is important for general practitioners to be aware of current recommendations for prevention of hepatitis A and B.

Obturator nerve entrapment. A cause of groin pain in athletes

Chronic groin pain in athletes is often difficult to diagnose and treat. There are many anatomic structures in the inguinal and groin region that have the potential to cause pain. We report 32 cases of a previously undescribed condition in athletes of "obturator neuropathy," a fascial entrapment of the obturator nerve where it enters the thigh. This condition represents a type of groin pain in athletes that is treatable by surgical means. There is a characteristic clinical pattern of exercise-induced medial thigh pain commencing in the region of the adductor muscle origin and radiating distally along the medial thigh. Needle electromyography demonstrates denervation of the adductor muscles. Surgical neurolysis treatment provides the definitive cure of this problem, with athletes returning to competition within several weeks of treatment. The surgical findings are entrapment of the obturator nerve by a thick fascia overlying the short adductor muscle. The role of conservative treatment in the management of this condition is unknown at present.

The effects of extending cognitive-behavioral therapy for binge eating disorder among initial treatment nonresponders

OBJECTIVE

The study was designed with the aim of determining whether extending group cognitive-behavioral therapy (CBT) would enhance outcome among individuals with binge eating disorder (BED) who failed to stop binge eating after an initial 12-week CBT intervention.

METHOD

Forty-six participants who met diagnostic criteria for BED were randomly allocated to either a 12-week group CBT intervention or a waiting list control condition. At the end of 12 weeks, treated participants who met clinical criteria for improvement subsequently received 12 sessions of behavioral weight loss. Remaining participants received 12 additional sessions of CBT for binge eating.

RESULTS

Fifty percent of treated participants improved with the initial 12-week course of CBT. There was a strong trend for the extension of CBT to affect improvement in binge eating among initial nonresponders (6 of 14 subjects no longer met diagnostic criteria for BED). Overall, extending CBT led to clinical improvement in 66.7% of all treated participants, with treatment gains occurring through session 20.

DISCUSSION

The results suggest that an extended course of CBT (i.e., longer than 12 weeks) will likely maximize the number of potential responders to treatment.

Systemic scleroderma. Multicenter trial of 1 year of treatment with recombinant interferon gamma

OBJECTIVE

To confirm significant improvement of the skin score in systemic sclerosis by treatment with interferon gamma in a larger group of patients and to investigate on a molecular level the influence of interferon gamma on collagen type I messenger RNA expression.

DESIGN

Open, noncontrolled multicenter study.

SETTING

Five outpatient clinics specializing in the care of systemic scleroderma.

PATIENTS

Thirty-two patients suffering from the diffuse or limited form of systemic sclerosis and progressive disease were recruited; 20 patients finished the study.

INTERVENTION

Each patient received interferon gamma, 50 micrograms subcutaneously 3 times a week for 1 year.

MAIN OUTCOME MEASURE

Skin score, collagen type I messenger RNA in skin biopsy specimens.

RESULTS

The patients who completed the study showed an unchanged median skin score after 1 year of therapy. In addition, similar collagen type I messenger RNA levels were detected in skin biopsy specimens taken from involved skin before and after therapy in these patients.

CONCLUSIONS

Treatment of systemic scleroderma with interferon gamma is associated with stabilization of the skin score and lack of worsening of visceral involvement.

Double-blind, placebo-controlled study of intralesional interferon gamma for the treatment of localized scleroderma

BACKGROUND

Localized scleroderma is characterized by circumscribed fibrotic plaques and may progress to widespread skin involvement and fibrosis. Interferon gamma (IFN-gamma) has been shown to be a potent inhibitor of collagen synthesis and of the migration and proliferation of dermal fibroblasts.

OBJECTIVE

Our purpose was to determine whether IFN-gamma is effective in the treatment of localized scleroderma.

METHODS

A double-blind, randomized, placebo-controlled, multicenter study was conducted. Twenty-four patients with progressive lesions received 100 micrograms of IFN-gamma or placebo subcutaneously on 5 consecutive days for 2 weeks followed by 100 micrograms of IFN-gamma or placebo once weekly for 4 weeks. Thereafter patients were observed for 18 weeks. To determine whether improvement could be related to an altered level of collagen messenger RNA (mRNA), biopsy specimens were taken from uninvolved and involved skin before and after therapy.

RESULTS

The patients treated with IFN-gamma or placebo showed no significant difference in size or fibrosis of lesions or collagen type I mRNA synthesis. However, a reduction in the number of new lesions was observed in the IFN-gamma-treated group. The biopsy specimens obtained from involved skin showed a moderate increase of type I collagen and a significant decrease in the small proteoglycan decorin mRNA levels.

CONCLUSIONS

The results indicate that IFN-gamma is ineffective in the treatment of localized scleroderma, but may inhibit the development of new lesions.

Site-directed and linker insertion mutagenesis of herpes simplex virus type 1 glycoprotein H

The gH-gL complex of herpes simplex virus type 1 (HSV-1) is essential for virion infectivity and virus-induced cell fusion, but functional domains of the gH molecule remain to be defined. We have addressed this question by mutagenesis. A set of linker insertion mutants in HSV-1 gH was generated and tested in transient assays for their ability to complement a gH-negative virus. Insertions at three sites in the C-terminal third of the external domain affected the ability of gH to function in cell-cell fusion and virus entry, while insertions at six sites in the N-terminal half of the external domain induced conformational changes in gH such that it was not recognized by monoclonal antibody LP11, although expression at the cell surface was unchanged. A recombinant virus in which a potential integrin-binding motif, RGD, in gH was changed to the triplet RGE entered cells as efficiently as the wild type, indicating that HSV-1 entry is not mediated by means of the gH-RGD motif binding to cell surface integrins. Furthermore, mutagenesis of the glycosylation site which is positionally conserved in all herpesvirus gH sequences in close proximity to the transmembrane domain generated a recombinant virus that grew in vitro with wild-type single-step kinetics.

I(kappa)B(gamma) inhibits DNA binding of NF-kappaB p50 homodimers by interacting with residues that contact DNA

NF-(kappa)B is an inducible transcription factor that activates many cellular genes involved in stress and immune response and whose DNA binding activity and cellular distribution are regulated by I(kappa)B inhibitor proteins. The interaction between NF-(kappa)B p50 and DNA was investigated by protein footprinting using chemical modification and partial proteolysis. Both methods confirmed lysine-DNA contacts already found in the crystal structure (K-147, K-149, K-244, K-275, and K-278) but also revealed an additional contact in the lysine cluster K-77-K-78-K-80 which was made on an extended DNA. Molecular modelling of such a DNA-protein complex revealed that lysine 80 is ideally placed to make phosphate backbone contacts in the extended DNA. Thus, it seems likely that the entire AB loop, containing lysines 77, 78, and 80, forms a C-shaped clamp that closes around the DNA recognition site. The same protein footprinting approaches were used to probe the interaction of p50 with the ankyrin repeat containing proteins I(kappa)B(gamma) and I(kappa)B(alpha). Lysine residues in p50 that were protected from modification by DNA were also protected from modification by I(kappa)B(gamma) but not I(kappa)B(alpha). Similarly, proteolytic cleavage at p50 residues which contact DNA was inhibited by bound I(kappa)B(gamma) but was enhanced by the presence of I(kappa)B(alpha). Thus, I(kappa)B(gamma) inhibits the DNA binding activity of p50 by direct interactions with residues contacting DNA, whereas the same residues remain exposed in the presence of I(kappa)B(alpha), which binds to p50 but does not block DNA binding.

The management of common dislocations in the upper limb

Dislocations are among the many orthopaedic injuries that the general practitioner is expected to manage. Many are fairly straightforward to treat, however, there are also many pitfalls. In this paper we provide an overview of the common dislocations in the upper limb, and some that are less common but important to recognise. We have also described the important complications to watch out for and an indication as to which dislocations should be referred for specialist management.

An endoplasmic reticulum-retained herpes simplex virus glycoprotein H is absent from secreted virions: evidence for reenvelopment during egress

Although it is generally accepted that one of the first steps of herpesvirus egress is the acquisition of an envelope by nucleocapsids budding into the inner nuclear membrane, later events in the pathway are not well understood. We tested the hypothesis that the virus then undergoes de-envelopment, followed by reenvelopment at membranes outside the endoplasmic reticulum (ER), by constructing a recombinant virus in which the expression of an essential glycoprotein, gH, is restricted to the inner nuclear membrane-ER by means of the ER retention motif, KKXX. This targeting signal conferred the predicted ER localization properties on gH in recombinant virus-infected cells, and gH and gL polypeptides failed to become processed to their mature forms. Cells infected with the recombinant virus released particles with 100-fold less infectivity than those released by cells infected with the wild-type parent virus, yet the number of enveloped virus particles released into the medium was unaltered. These particles contained normal amounts of gD and VP16 but did not contain detectable amounts of gH, and these data are consistent with a model of virus exit whereby naked nucleocapsids in the cytoplasm acquire their final envelope from a subcellular compartment other than the ER-inner nuclear membrane.

An Mll-AF9 fusion gene made by homologous recombination causes acute leukemia in chimeric mice: a method to create fusion oncogenes

Homologous recombination in embryonal stem cells has been used to produce a fusion oncogene, thereby mimicking chromosomal translocations that frequently result in formation of tumor-specific fusion oncogenes in human malignancies. AF9 sequences were fused into the mouse Mll gene so that expression of the Mll-AF9 fusion gene occurred from endogenous Mll transcription control elements, as in t(9;11) found in human leukemias. Chimeric mice carrying the fusion gene developed tumors, which were restricted to acute myeloid leukemias despite the widespread activity of the Mll promoter. Onset of perceptible disease was preceded by expansion of ES cell derivatives in peripheral blood. This novel use of homologous recombination formally proves that chromosomal translocations contribute to malignancy and provides a general strategy to create fusion oncogenes for studying their role in tumorigenesis.

Improving outpatient clinic staffing and scheduling with computer simulation

Patient flow in an appointment-based, outpatient internal medicine clinic involving multiple, sequential providers-registrar, triage nurse, physician, and discharger-was studied using computer simulation. Provider task time distributions were obtained through a time-motion study and then input into the computer program, which simulated the clinic situation well. Time interval and sensitivity analyses yielded insights into staffing levels, appointment times, and clinic dynamics. A bottleneck provider was shown, and patient time in the clinic was related to the time of appointment and was slowed by having too many doctors in the clinic. Subsequent operational changes significantly decreased the average observed patient total time in clinic from 75.4 (SD 34.2) minutes to 57.1 (SD 30.2) minutes (p < .001, t test).

Sleeping position and upper airways bacterial flora: relevance to cot death

The hypothesis that the prone sleeping position is associated with accumulation of upper airways secretions and increased bacterial growth was investigated in adults. Ten subjects with upper respiratory tract infection lay prone for one hour and then supine for one hour. Nasal swabs after the prone period yielded higher bacterial counts than swabs obtained after the supine period. This result could be relevant to sudden infant death syndrome (SIDS), as infants who sleep in the prone position are at increased risk of SIDS and one theory is that death is caused by toxins produced by bacterial overgrowth in the upper respiratory tract following a viral infection.

Neonatal osteofibrous dysplasia: report of two cases

Skeletal neoplasms of the newborn and neonatal period are infrequently encountered and often misdiagnosed. Osteofibrous dysplasia is a tumor of childhood that may be seen in the newborn. Because of its unique natural history, with and without surgical treatment, and the similarity in radiographic appearance of this tumor to other lesions, a high index of suspicion must be maintained when a tibial lesion is encountered in the newborn. We present two additional cases of neonatal osteofibrous dysplasia and discuss the differential diagnostic considerations.

Psychological response to cervical screening

BACKGROUND

Few studies have examined the psychological costs of cervical screening, despite expressed concern over possible negative sequelae.

METHODS

Seventy-five women with mild or moderately dyskaryotic smears, under cytological surveillance, 75 women referred for colposcopy after a first-ever abnormal smear showing severe dyskaryosis, and 75 controls with recent negative cytology were interviewed at home, and their psychological adjustment was assessed.

RESULTS

Levels of distress were higher among women with an abnormal smear than among controls with a recent negative smear. Anxiety (Hospital Anxiety and Depression Scale range 0-21, "normal" range 0-7) was highest among those referred for colposcopy (mean 8.12, controls 5.88, P < 0.001); afterward, distress fell (mean 6.61, P < 0.001) but more problems of social adjustment were evident (surveillance vs controls, P < 0.01). High anxiety was associated with social maladjustment (colposcopy, P < 0.001; surveillance, P < 0.01) and negative feelings about the self (P < 0.05). Current anxiety was unrelated to knowledge about abnormal smears, but in the surveillance group was related to satisfaction with the explanation provided (P < 0.05).

CONCLUSION

A positive cervical smear may by psychologically traumatic for a significant minority of women, irrespective of management strategy.

The origin recognition complex in silencing, cell cycle progression, and DNA replication

This report describes the isolation of ORC5, the gene encoding the fifth largest subunit of the origin recognition complex, and the properties of mutants with a defective allele of ORC5. The orc5-1 mutation caused temperature-sensitive growth and, at the restrictive temperature, caused cell cycle arrest. At the permissive temperature, the orc5-1 mutation caused an elevated plasmid loss rate that could be suppressed by additional tandem origins of DNA replication. The sequence of ORC5 revealed a potential ATP binding site, making Orc5p a candidate for a subunit that mediates the ATP-dependent binding of ORC to origins. Genetic interactions among orc2-1 and orc5-1 and other cell cycle genes provided further evidence for a role for the origin recognition complex (ORC) in DNA replication. The silencing defect caused by orc5-1 strengthened previous connections between ORC and silencing, and combined with the phenotypes caused by orc2 mutations, suggested that the complex itself functions in both processes.

Urinary creatinine adjusted reference ranges for homovanillic and vanillylmandelic acid in children and adults

The relationship between urinary homovanillic acid (HVA), vanillylmandelic acid (VMA) and creatinine is investigated and reference ranges are constructed for HVA and VMA. A total of 769 urine samples were obtained from children and adults. The ratios HVA/creatinine and VMA/creatinine were highly correlated with creatinine concentration; hence, reference to creatinine was found to be an inappropriate adjustment for urinary dilution. An alternative method based upon linear regression is proposed. After allowing for differing levels of creatinine, HVA and VMA were found to be significantly correlated with age, height and weight for individuals aged less than 20 years. In those aged over 20 years, HVA was significantly correlated with weight and VMA with age. Differences between sexes were found in the levels of HVA and VMA, the exception being VMA in the over 20 age group. Reference ranges were constructed for HVA and VMA which are variously dependent upon creatinine, age, sex and weight.

Cardiac allograft vascular disease. Relationship to microvascular cell surface markers and inflammatory cell phenotypes on endomyocardial biopsy

BACKGROUND

Cardiac allograft vascular disease is characterized by accelerated and diffuse intimal proliferation involving both the microvasculature and epicardial vessels. Because in vivo documentation of this complication is now possible with intracoronary ultrasound imaging, we can examine the relationship of intimal proliferation to markers of immunity and endothelial activation. We hypothesize that alterations of microvascular cell surface markers likely mirror changes in the epicardial vessels that may be important in the pathophysiology of intimal proliferation.

METHODS AND RESULTS

Forty-three heart transplant patients were examined by intracoronary ultrasound more than 1 year after transplantation, and these images were analyzed to obtain mean intimal thickness and intimal thickness class (I through IV), calculated from the mean thickness and circumferential involvement. Right ventricular endomyocardial biopsies obtained at the time of intracoronary ultrasound were examined by immunohistochemistry to detect microvascular expression of histocompatibility leukocyte antigen (HLA) classes I and II (HLA ABC, DR, DP, and DQ); endothelial-specific antigen detected by the monoclonal antibody E 1.5; intercellular adhesion molecules (ICAM-1); CD4+ and CD8+ lymphocytes and macrophages (CD 14+). Microvascular antigen expression was graded 1 through 5 on the basis of the diffuseness of positive staining. The number of each inflammatory cell phenotype present per high-power field was counted. By ANOVA, scores for HLA DR, HLA DQ, and E1.5 expression were lower in intimal thickness classes II, III, and IV compared with class I. This inverse relationship was significant by linear regression analysis of mean intimal thickness. Inflammatory cells were not significantly correlated with intimal thickening. Rejection incidence was higher, and time since transplantation longer, in intimal thickness classes II, III, and IV compared with class I.

CONCLUSION

Transplant coronary artery intimal proliferation is associated with alteration of microvascular endothelial cell surface markers. These changes in cell surface antigen expression could provide the substrate for coronary artery intimal proliferation and narrowing.