Infectious Mononucleosis: diagnosis and clinical interpretation.

EBV is the sole causative agent of the acute illness in humans described either as infectious mononucleosis (IM), or glandular fever. IM, when not clinically silent, can present in patients with at least two of the classic triad of symptoms of fever, pharyngitis, and lymphadenopathy. Challenges for the clinician arise when atypical cases present. Early, accurate and informed laboratory test results are vital for diagnosis, appropriate treatment, and management. A key challenge for the practitioner, particularly in cases where the illness can present atypically, is distinguishing bacterial tonsillitis infections from early acute IM. The ability to draw on timely, clear, and insightful laboratory results to distinguish viral from bacterial infection is vital. Correct and prompt diagnosis of IM can help prevent the unnecessary administration of antibiotics and mitigate the need for other expensive exploratory tests in cases of IM that present with splenomegaly, lymphadenopathy, or suspect haematological conditions. Good communication between the requesting clinician and those carrying out the investigative process, and between the different laboratory departments involved, is good practice and would ultimately benefit the patient. This communication will comprehensively review the aetiology, clinical presentation, and laboratory findings in IM with a view to promoting further research and so derive a standard diagnostic algorithm of the condition.

Novel implications of Lingo-1 and its signaling partners in schizophrenia.

Myelination and neurite outgrowth both occur during brain development, and their disturbance has been previously been implicated in the pathophysiology of schizophrenia. Leucine-rich repeat and immunoglobulin domain-containing protein (Lingo-1) is a potent negative regulator of axonal myelination and neurite extension. As co-factors of Lingo-1 signaling (Nogo receptor (NgR), With No Lysine (K) (WNK1) and Myelin transcription factor 1 (Myt1)) have been implicated in the genetics of schizophrenia, we explored for the first time the role of Lingo-1 signaling pathways in this disorder. Lingo-1 protein, together with its co-receptor and co-factor proteins NgR, tumor necrosis factor (TNF) receptor orphan Y (TROY), p75, WNK1 and Myt1, have never been explored in the pathogenesis of schizophrenia. We examined protein levels of Lingo-1, NgR, TROY, p75, WNK1, Myt1 and myelin basic protein (MBP) (as a marker of myelination) within the post-mortem dorsolateral prefrontal cortex (DLPFC) (37 schizophrenia patients versus 37 matched controls) and hippocampus (Cornu Ammonis, CA1 and CA3) (20 schizophrenia patients versus 20 matched controls from the same cohort). Both of these brain regions are highly disrupted in the schizophrenia pathophysiology. There were significant increases in Lingo-1 (P<0.001) and Myt1 (P=0.023) and a reduction in NgR (P<0.001) in the DLPFC in schizophrenia subjects compared with controls. There were also increases in both TROY (P=0.001) and WNK1 (P=0.011) in the CA1 of schizophrenia subjects and, in contrast to the DLPFC, there was an increase in NgR (P=0.006) in the CA3 of schizophrenia subjects compared with controls. No significant difference was reported for MBP levels (P>0.05) between the schizophrenia and control groups in the three tested regions. This is the first time that a study has shown altered Lingo-1 signaling in the schizophrenia brain. Our novel findings may present a direct application for the use of a Lingo-1 antagonist to complement current and future schizophrenia therapies.

Cerebral palsy following neonatal hypoxic seizures in singleton term infants: the influence of parity.

This was a retrospective review of term singleton neonates (> 37 weeks) with early onset seizures, with and without encephalopathy, from 1989 through 2000. Our aim was to examine the relationship between antepartum and intrapartum obstetric events, neonatal hypoxic seizures and subsequent neurological impairment of 77,838 infants, the incidence of seizures was significantly higher among primiparas (2.4/1000; 67/31,729) compared with multiparas (0.35/1000; 16/46,109)(p < 0.001). Compared with multiparas, seizures with encephalopathy occurred more frequently among primiparas (0.8/1000; 26/31,729) vs. multiparas (0.2/1000; 8/46,109), were more commonly associated with unexplained intrapartum hypoxia (0.6/1000, n = 20 vs.0.04/ 1000, n = 2) and the incidence of cerebral palsy, 45% (9/20) vs. 0% (0/2) was significantly higher(p < 0.001). Seizures with encephalopathy (0.2/1000 vs.0.13/1000) and cerebral palsy (33%) had a similar incidence in primiparas and multiparas following a sentinel event. Neonatal seizures with encephalopathy, related to intrapartum events, were 4 times more common following first delivery and associated with a 9 fold higher incidence of cerebral palsy, implicating primiparous labor in the development of cerebral palsy.

Babies behind bars; an Irish perspective.

In the Irish Prison service prison is not deemed suitable for babes. Rarely are mothers separated from their children in Ireland as they get temporary release renewed weekly to keep her at home with her baby. The governor explained the system of the prison which I detail below. The women's prison is now known as the Dochas Centre meaning hope, named so by the women themselves. We found that 14 babies lived in the centre with their mothers in the last 4 years. Their length of stay ranged from 2 days to 3 months. Of the 14 babies in prison, five were born to women who were pregnant on admission and the other nine brought their babies with them. Six women are separated from their children, in total 24, due to her incarceration. The implications are that a formal system is needed to plan the baby's admission, stay and discharge with formal links with HSE health and child protection systems where necessary. The HSE and the Irish prison's service are looking at further amalgamation or integration of health care into the prison system.

Varicella outbreak in a residential home.

We report an outbreak of varicella in a residential home for 29 children(aged 4 to 16 years) with severe physical and learning disability. We report our group's incidence, complication and hospitalisation rate of varicella despite anti-viral therapy. As we did not have a control group we use statistics pertaining to the general population for comparison. All 15 non-immune children contracted varicella within 30 days of the index case. The complication rate was 9 in 15, three time higher than in the general population. The hospitalisation rate was 5 in 15. This is remarkably high. The incidence of hospitalisation in the general population is 1 to 5 per 1,000. In conclusion we suggest that the guidelines for varicella vaccination should include all non-immune children and adults with severe to profound physical and learning disability. We recommend that this disease should be notifiable in the severely physically disabled population. We recommend that within 3 days of exposure to varicella children with severe to profound physical and learning disability are vaccinated to prevent infection (post exposure prophylaxis). These findings are important in countries where varicella vaccination is not part of the routine vaccination program and is not part of the routine vaccination program and is only offered to select groups of children.

Expression of the antimicrobial peptides in plants to control phytopathogenic bacteria and fungi.

Three antimicrobial peptides exhibiting in vitro antifungal activity were expressed in Arabidopsis to compare their in planta activity. Beta-Purothionin, cecropin B, and phor21 were expressed under an endogenous promoter with moderate-level activity and excreted extracellularly. Expression of beta-purothionin rendered the greatest antibacterial and antifungal resistance while cecropin B enhanced only antibacterial activity and phor21 did not improve antimicrobial resistance. The transgenic beta-purothionin arrested fungal growth on leaf surfaces and infection of stomata. Leaf extracts from plants producing beta-purothionin and cecropin B displayed membrane permeabilizing activity. The in planta antimicrobial activity of the tested peptides was consistent with previously reported in vitro experiments. The expression strategy allowed enhanced antifungal resistance without high-level transgene expression.

Xp22.3 microdeletion in a 19-year-old girl with clinical features of MLS syndrome.

We describe a 19-year-old girl who has clinical features of microphthalmia with linear skin defects (MLS) syndrome caused by a microdeletion of Xp22.3. In addition to the classical ocular abnormalities and linear skin defects she has other features not previously described. She was previously reported in this journal in 1990 as poikiloderma congenitale, but her true diagnosis of an Xp22.3 microdeletion was clarified when fluorescent in situ hybridization (FISH) analysis indicated that one of her X chromosomes had a microdeletion including the KAL gene. We describe this patient with an Xp22.3 microdeletion to heighten awareness among dermatologists of this syndrome and to underscore the difficulties in diagnosing MLS syndrome.

Characterization of the caprine model for ruminant brucellosis.

The relationship between man, the goat, and brucellosis is historical. Today Brucella melitensis and Brucella abortus pose a serious economic and public health threat in many countries throughout the world. Infection of pregnant goats and sheep with B. melitensis results in abortion during the third trimester of pregnancy. Although nearly eradicated in the US, bovine brucellosis is still a problem in many countries and the potential for re-infection of domestic stock from wildlife reservoirs in this country is a regulatory nightmare. Humans infected with this pathogen develop undulant fever, which is characterized by pyrexia, arthritis, osteomyelitis, and spondylitis. Although available for both organisms, currently available vaccines have problems ranging from false positive serological reactions to limited efficacy in different animal species. With the continued need for new and better vaccines, we have further developed a goat model system to test new genetically derived strains of B. melitensis and B. abortus for virulence as measured by colonization of maternal and fetal tissues, vaccine safety, and vaccine efficacy.

Pathogenicity and protective activity in pregnant goats of a Brucella melitensis Deltaomp25 deletion mutant.

The Brucella melitensis mutant BM 25, which lacks the major 25 kDa outer membrane protein Omp25, has previously been found to be attenuated in the murine brucellosis model. In the present study, the capacity of the Deltaomp25 mutant to colonise and cause abortions in the caprine host was evaluated. The vaccine potential of BM 25 was also investigated in goats. Inoculation of nine pregnant goats in late gestation with the B. melitensis mutant resulted in 0/9 abortions, while the virulent parental strain, B. melitensis 16M, induced 6/6 dams to abort (P<0.001, n=6). BM 25 also colonised fewer adults (P<0.05, n=6) and kids (P<0.01, n=6) than strain 16M. The Deltaomp25 mutant was found capable of transient in vivo colonisation of non-pregnant goats for two weeks post-infection. Owing to the ability of BM 25 to colonise both non-pregnant and pregnant adults without inducing abortions, a vaccine efficacy study was performed. Vaccination of goats prior to breeding with either BM 25 or the current caprine vaccine B. melitensis strain Rev. 1 resulted in 100 per cent protection against abortion following challenge in late gestation with virulent strain 16M (P<0.05, n=7). However, unlike strain Rev. 1, BM 25 does not appear to cause abortions in late gestation based on this study with a small number of animals. The B. melitensis Deltaomp25 mutant, BM 25, may be a safe and efficacious alternative to strain Rev. 1 when dealing with goat herds of mixed age and pregnancy status.

Oral vaccination of sexually mature pigs with Brucella abortus vaccine strain RB51.

OBJECTIVE: To develop a novel oral vaccine delivery system for swine, using the rough vaccine strain of Brucella abortus. ANIMALS: 56 crossbred pigs from a brucellosis-free facility. PROCEDURE: In 3 separate experiments, pigs were orally vaccinated with doses of 1 x 10(9) to > 1 x 10(11) CFU of strain RB51 vaccine. The vaccine was placed directly on the normal corn ration, placed inside a whole pecan, or mixed with cracked pecans and corn. RESULTS: Oral vaccination of pigs with vaccine strain RB51 resulted in a humoral immune response to strain RB51 and short-term colonization of the regional lymph nodes. CONCLUSIONS AND CLINICAL RELEVANCE: A viscous liquid such as Karo corn syrup in association with pecans that scarify the oral mucosa are necessary when placing the live vaccine directly onto corn or other food rations. Doses of > 1 x 10(11) CFU of RB51 organisms/pig in this mixture ensures 100% colonization of regional lymph nodes via the oral route. This method may allow an efficient and economical means to vaccinate feral swine for brucellosis.

Targeted destruction of androgen-sensitive and -insensitive prostate cancer cells and xenografts through luteinizing hormone receptors.

BACKGROUND: We have prepared a conjugate of a lytic peptide (hecate) and a 15-amino acid segment of the beta-chain of LH to test the concept that this conjugate will target cancer cells expressing LH receptors. METHODS: Hecate-betaLH was added in vitro to cultures of Chinese hamster ovary (CHO) cells with and without LH receptors and to prostate cancer cells in the presence or absence of steroids, follicle-stimulating hormone (FSH), epidermal growth factor (EGF), or betaLH. PC-3 xenografts were established in male athymic nude mice and treated once a week for 3 weeks with hecate-betaLH via the lateral tail vein. RESULTS: The conjugate showed concentration-dependent toxicity for the following prostate cancer cell lines: BRF 41 T>DU145>PC-3>LNCaP, according to their LH receptor capacities. Steroid removal reduced sensitivity to the drug in a reversible manner. Hecate-betaLH reduced the tumor burden in the nude mice from 60 to 12.5 mg/g body weight. CONCLUSIONS: We conclude that the hecate-betaLH conjugate selectively kills androgen-dependent and-independent prostate cancer cells both in vivo and in vitro; its toxicity depends on the number of LH receptor sites present.

Targeted destruction of prostate cancer cells and xenografts by lytic peptide-betaLH conjugates.

In series of experiments conducted in vitro, we have established the concept that conjugates of the lytic peptides Hecate or Phor14 with a fragment of the beta chain of LH (amino acids 80-94) selectively destroy both androgen sensitive and insensitive human prostate cancer cells. Extraction of steroids from the culture medium by charcoal reduced the ability of the conjugates to kill LNCaP, BRF41T and PC-3 cells. Addition of hormones known to up-regulate LH receptors (estradiol, testosterone or FSH) to the culture medium restored the ability of the conjugates to kill these cell lines. The toxicity of the conjugates (EC(50)) to these cell lines was closely correlated to their LH binding capacities (f mol/10(6) cells). In series of in vivo experiments we have shown that both the Hecate and Phor14-betaLH conjugates are remarkably effective in causing tumor cell necrosis and cessation of tumor growth in nude athymic mice. Treatment with Hecate-betaLH (12 mg/kg body weight) resulted in a reduction of tumor burden (mg tumor/g body weight) from 60 to 14 (P<0.0001); treatment with Phor14-betaLH (12 mg/kg body weight) reduced tumor burden to 27 mg (P<0.0001). Treatment with a high dose of Phor14-betaLH (24 mg/kg body weight) reduced the tumor burden from 60 to 12 mg/kg P<0.0001). Pretreatment of animals receiving a low dose of Phor14-betaLH (12 mg/kg) with either estradiol or follicle stimulating hormone, (FSH) resulted in reduction of tumor burden from 60 to 11 mg/kg. Administration of a second 3-week treatment after a one month recovery period caused complete regression of more than 75 percent of the tumors. No changes in body weight or histological abnormalities were found in any of the organs examined, except the testes.

Coronavirus and Pasteurella infections in bovine shipping fever pneumonia and Evans' criteria for causation.

Respiratory tract infections with viruses and Pasteurella spp. were determined sequentially among 26 cattle that died during two severe epizootics of shipping fever pneumonia. Nasal swab and serum samples were collected prior to onset of the epizootics, during disease progression, and after death, when necropsies were performed and lung samples were collected. Eighteen normal control cattle also were sampled at the beginning of the epizootics as well as at weekly intervals for 4 weeks. Respiratory bovine coronaviruses (RBCV) were isolated from nasal secretions of 21 and 25 cattle before and after transport. Two and 17 cattle nasally shed Pasteurella spp. before and after transport, respectively. RBCV were isolated at titers of 1 x 10(3) to 1.2 x 10(7) PFU per g of lung tissue from 18 cattle that died within 7 days of the epizootics, but not from the lungs of the remaining cattle that died on days 9 to 36. Twenty-five of the 26 lung samples were positive for Pasteurella spp., and their CFU ranged between 4.0 x 10(5) and 2.3 x 10(9) per g. Acute and subacute exudative, necrotizing lobar pneumonia characterized the lung lesions of these cattle with a majority of pneumonic lung lobes exhibiting fibronecrotic and exudative changes typical of pneumonic pasteurellosis, but other lung lobules had histological changes consisting of bronchiolitis and alveolitis typical of virus-induced changes. These cattle were immunologically naive to both infectious agents at the onset of the epizootics, but those that died after day 7 had rising antibody titers against RBCV and Pasteurella haemolytica. In contrast, the 18 clinically normal and RBCV isolation-negative cattle had high hemagglutinin inhibition antibody titers to RBCV from the beginning, while their antibody responses to P. haemolytica antigens were delayed. Evans' criteria for causation were applied to our findings because of the multifactorial nature of shipping fever pneumonia. This analysis identified RBCV as the primary inciting cause in these two epizootics. These viruses were previously not recognized as a causative agent in this complex respiratory tract disease of cattle.

Attenuation and immunogenicity of a Brucella abortus htrA cycL double mutant in cattle.

PHE1 is a htrA cycL double gene deletion mutant of virulent Brucella abortus strain 2308 (S2308) which has previously been evaluated in the murine and caprine models of bovine brucellosis. This report describes the results of studies conducted with this mutant in the natural bovine host. Six sexually mature, non-gravid heifers were inoculated via the conjunctival sac with 1 x 10(10) colony forming units (CFU) of either the parental S2308 or the htrA cycL gene deletion mutant, PHE1. At 4, 7 and 11 days post-inoculation, PHE1 was found to colonize the bovine host at lower levels than S2308. In a second experiment, eight heifers in mid-gestation were infected with 1 x 10(7) CFU of either strain via the conjunctival sac. The virulent S2308 caused abortions or weak calves in 4/4 cows, while all four cows infected with PHE1 had healthy calves. Furthermore, PHE1 exhibited decreased resistance to killing by cultured bovine neutrophils and macrophages compared to the parental strain. These studies demonstrate that the B. abortus htrA cycL gene deletion mutant PHE1 is highly attenuated in the bovine host when compared to the virulent parental S2308.

Safety of Brucella abortus strain RB51 in bull elk.

Some of the elk (Cervus elaphus nelsoni) of the Greater Yellowstone Area (Wyoming, Idaho, Montana; USA) are infected with Brucella abortus, the bacterium that causes bovine brucellosis. Brucella abortus strain RB51 vaccine is being considered as a means to control B. abortus induced abortions in cow elk. However, the most probable vaccination strategies for use in free-ranging elk might also result in some bull elk being inoculated, thus, it is important to insure that the vaccine is safe in these animals. In the winter of 1995, 10 free-ranging bull elk calves were captured, tested for B. abortus antibodies, and intramuscularly inoculated with 1.0 x 10(9) colony forming units (CFU) of B. abortus strain RB51. Blood was collected for hemoculture and serology every 2 wk after inoculation for 14 wk. Beginning 4 mo postinoculation and continuing until 10 mo postinoculation elk were serially euthanized, necropsied, and tissues collected for culture and histopathology. These elk cleared the organism from the blood within 6 wk and from all tissues within 10 mo. No lesions attributable to B. abortus were found grossly and only minimal to mild lymphoplasmacytic epididymitis was found in a few elk on histologic examination. In a separate study, six adult bull elk from Wind Cave National Park (South Dakota, USA) were taken to a ranch near Carrington (North Dakota, USA). Three were orally inoculated with approximately 1.0 x 10(10) CFU of RB51 and three were inoculated with corn syrup and saline. Ninety days post-inoculation semen was examined and cultured from these bulls. Strain RB51 was not cultured from their semen at that time. There were no palpable abnormalities in the genital tract and all elk produced viable sperm. Although they contain small sample sizes, these studies suggest that B. abortus strain RB51 is safe in bull elk.

Effect of the antimicrobial peptide, D-hecate, on trichomonads.

Tritrichomonas foetus and Trichomonas vaginalis are protozoan parasites that cause sexually transmitted diseases in cattle and humans, respectively. There is a need for new antimicrobial agents to treat or prevent trichomoniasis because there are currently no approved chemotherapeutic agents against T. foetus and resistance of T. vaginalis to metronidazole does occur. Therefore, we evaluated the effect of a novel antimicrobial peptide, D-hecate, on the viability of 6 isolates of T. foetus and T. vaginalis in vitro. Tritrichomonas foetus and T. vaginalis were grown to mid log phase (24 hr) or late log/stationary phase (48 hr). Parasites at 10(6)/ml were mixed with equal volumes of D-hecate to final concentrations of 10 microM, 20 microM. and 40 microM of D-hecate. Controls had minimal essential medium (MEM) alone. The numbers of viable parasites were determined microscopically after 10, 20, and 30 min of incubation at 37 C with D-hecate or MEM. Our results show that D-hecate killed all 6 isolates of T. foetus and T. vaginalis evaluated. The killing effect was dependent on the concentration of the peptide, incubation time, and phase of growth of the parasites. Ultrastructural studies of parasites treated with 10 microM of D-hecate revealed extensive damage to the plasma membrane of most T. foetus and T. vaginalis cells, while a few cells were distorted but remained intact. D-Hecate may be a useful chemotherapeutic agent for the treatment of trichomoniasis.

Validation of the fluorescence polarization assay as a serological test for the presumptive diagnosis of porcine brucellosis.

Sera from Canadian pigs (brucellosis free, n = 14037) and sera from pigs infected with Brucella suis (n = 401) were tested by the buffered antigen plate agglutination test, the complement fixation test, an indirect and a competitive enzyme immunoassay and a fluorescence polarization assay. The results were analysed and assay sensitivity and specificity estimates were calculated. The sensitivity and specificity of the tests were as follows: the buffered antigen plate agglutination test, 77.1 and 96.9%; the complement fixation test (considering anticomplementary sera as negative), 93.3 and 95.5%; the complement fixation test (considering anticomplementary sera as positive), 58.1 and 99.9%; the indirect enzyme immunoassay, 94.0 and 97.9%; the competitive enzyme immunoassay, 90.8 and 96.6%; and the fluorescence polarization assay, 93.5 and 97.2%; respectively. It was concluded that the fluorescence polarization assay was a valuable asset to the diagnosis of porcine brucellosis because of its accuracy, ease of performance and relative cost.

Striae and acne following cardiac surgery in a child.

We report a 13-year-old girl with extensive striae and an acneiform eruption following surgery for complex congenital heart disease. These findings were associated with elevated serum and urinary cortisol levels with loss of diurnal rhythm. The resolution of the eruption and the fading of her striae coincided in time with normalization of her blood parameters on day 72 postoperatively. We conclude that the cause of steroid excess in our patient was stress induced by the cardiac surgery and a complicated and protracted postoperative course. To our knowledge, this is the first report in the English language literature of skin changes due to endogenous hypercortisolaemia caused by intense physical and emotional stress.

Protection against infection and abortion induced by virulent challenge exposure after oral vaccination of cattle with Brucella abortus strain RB51.

OBJECTIVES: To determine efficacy of orally administered Brucella abortus vaccine strain RB51 against virulent B abortus challenge exposure in cattle as a model for vaccination of wild ungulates. ANIMALS: 20 mixed-breed beef cattle obtained from a brucellosis-free herd. PROCEDURE: Sexually mature, Brucella-negative beef heifers were vaccinated by mixing > 10' viable RB51 organisms or diluent with their feed. Heifers were fed individually and consumed their entire ration. Each heifer received approximately 3 X 10' colony-forming units (CFU). Six weeks after oral vaccination, heifers were pasture-bred to brucellosis-free bulls. At approximately 186 days' gestation, heifers were challenge exposed conjunctively with 107 CFU of virulent B abortus strain 2308. RESULTS: Vaccination with the rough variant of B abortus RB51 did not stimulate antibodies against the O-polysaccharide (OPS) of B abortus. After challenge exposure and parturition, strain 2308 was recovered from 80% of controls and only 20% of vaccinates. Only 30% of the vaccinates delivered dead, premature, or weak calves, whereas 70% of the controls had dead or weak calves. CONCLUSIONS: Cattle vaccinated orally with the rough variant of B abortus strain RB51 develop significant (P < 0.05) protection against abortion and colonization and do not produce OPS-specific antibodies. Clinical Relevance-Results encourage further investigation into use of strain RB51 to vaccinate wild ungulates (elk and bison) orally.