Exploiting tumor-specific defects in the interferon pathway with a previously unknown oncolytic virus

Interferons are circulating factors that bind to cell surface receptors, activating a signaling cascade, ultimately leading to both an antiviral response and an induction of growth inhibitory and/or apoptotic signals in normal and tumor cells. Attempts to exploit the ability of interferons to limit the growth of tumors in patients has met with limited results because of cancer-specific mutations of gene products in the interferon pathway. Although interferon-non-responsive cancer cells may have acquired a growth/survival advantage over their normal counterparts, they may have simultaneously compromised their antiviral response. To test this, we used vesicular stomatitis virus (VSV), an enveloped, negative-sense RNA virus exquisitely sensitive to treatment with interferon. VSV rapidly replicated in and selectively killed a variety of human tumor cell lines even in the presence of doses of interferon that completely protected normal human primary cell cultures. A single intratumoral injection of VSV was effective in reducing the tumor burden of nude mice bearing subcutaneous human melanoma xenografts. Our results support the use of VSV as a replication-competent oncolytic virus and demonstrate a new strategy for the treatment of interferon non-responsive tumors.

The murine double-stranded RNA-dependent protein kinase PKR is required for resistance to vesicular stomatitis virus

Interferon (IFN)-induced antiviral responses are mediated through a variety of proteins, including the double-stranded RNA-dependent protein kinase PKR. Here we show that fibroblasts derived from PKR(-/-) mice are more permissive for vesicular stomatitis virus (VSV) infection than are wild-type fibroblasts and demonstrate a deficiency in alpha/beta-IFN-mediated protection. We further show that mice lacking PKR are extremely susceptible to intranasal VSV infection, succumbing within days after instillation with as few as 50 infectious viral particles. Again, alpha/beta-IFN was unable to rescue PKR(-/-) mice from VSV infection. Surprisingly, intranasally infected PKR(-/-) mice died not from pathology of the central nervous system but rather from acute infection of the respiratory tract, demonstrating high virus titers in the lungs compared to similarly infected wild-type animals. These results confirm the role of PKR as the major component of IFN-mediated resistance to VSV infection. Since previous reports have shown PKR to be nonessential for survival in animals challenged with encephalomyocarditis virus, influenza virus, and vaccinia virus (N. Abraham et al., J. Biol. Chem. 274:5953-5962, 1999; Y. Yang et al., EMBO J. 14:6095-6106, 1995), our findings serve to highlight the premise that host dependence on the various mediators of IFN-induced antiviral defenses is pathogen specific.

Concordance between p53 protein overexpression and gene mutation in a large series of common human carcinomas

Immunohistochemical (IHC) detection of p53 protein was compared with the presence of p53 gene mutation in many colorectal (n = 100), breast (n = 92), endometrial (n = 122), and gastric (n = 116) carcinomas. Two commercially available antibodies, DO7 and CM1, were used for IHC analysis of paraffin-embedded tissue sections. Screening for gene mutations in frozen and paraffin-embedded tumor samples was carried out using polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP). The frequency of nuclear staining with DO7 or CM1 for each tumor type, respectively, was colorectal (36%, 23%); breast (15%, 19%); endometrial (21%, 33%); and gastric (23%,-). Overall correlation between the two antibodies for nuclear staining was 90% for the 314 tumors analyzed. Cytoplasmic staining was observed with DO7 in 7% of breast and 5% of gastric carcinomas and with CM1 in 17% of breast and 54% of endometrial carcinomas. p53 gene mutation was found in 39% of colorectal, 28% of breast, 13% of endometrial, and 25% of gastric cancers. The concordance between p53 nuclear overexpression and gene mutation (both positive or both negative) was 68% for colorectal, 79% for breast, 76% for endometrial, and 73% for gastric carcinomas. This study provides further evidence that IHC detection of p53 protein accumulation does not always indicate the presence of a gene mutation and vice versa. Discordant results were observed in approximately 20% to 30% of the tumors studied, highlighting the need for careful characterization of both p53 gene and protein alterations when assessing the relationship between p53 status and tumor behavior.

Should celecoxib be contraindicated in patients who are allergic to sulfonamides? Revisiting the meaning of 'sulfa' allergy

Celecoxib, a selective cyclo-oxygenase-2 inhibitor, is a diaryl-substituted pyrazole derivative containing a sulfonamide substituent. Because of this structural component, celecoxib is contraindicated for use in patients who have demonstrated allergic reactions to sulfonamides. However, there is a lack of data demonstrating cross-reactivity among sulfonamide medications. A sulfonamide is any compound with an SO2NH2 moiety. The major difference between sulfonamide antimicrobials and other sulfonamide-containing medications such as furosemide, thiazide diuretics and celecoxib, is that sulfonamide antimicrobials contain an aromatic amine group at the N4 position. This allows for division of the sulfonamides into 2 groups: aromatic amines (i.e., sulfonamide antimicrobials) and nonaromatic amines. In addition, sulfonamide antimicrobials contain a substituted ring at the N1-position; this group is not found with nonaromatic amine-containing sulfonamides. Adverse reactions to sulfonamide antimicrobials include type I, or immunoglobulin (Ig) E-mediated reactions, hypersensitivity syndrome reactions, and severe skin reactions such as toxic epidermal necrolysis. The aromatic amine portion of the sulfonamide antimicrobial is considered to be critical in the development of latter 2 reactions. In susceptible individuals, the hydroxylamine metabolite is unable to be detoxified leading to a cascade of cytotoxic and immunological events that eventually results in the adverse reaction. Since celecoxib does not contain the aromatic amine, adverse reactions such as hypersensitivity syndrome reactions and toxic epidermal necrolysis would not be expected to occur at the same frequency as they do with sulfonamide antimicrobials. Similarly, for IgE-mediated reactions, the N1-substituent and not the sulphonamide moiety is important in determining specificity to antibodies. Celecoxib and other nonaromatic amine-containing sulfonamide medications do not contain the N1-substituent. Cross-reactivity among the various sulfonamide-containing medications has also not been substantiated by published case reports. In fact, conflicting information exists in the literature. Reports showing lack of cross-reactivity balance the few case reports suggesting cross-reactivity. Cross-reactivity between sulfonamide medications should be based on scientific data, including chemistry, metabolism, immune responses and clinical data. Based on the current information, there is no documentation for cross-reactivity between sulfonamide antimicrobials and other sulfonamide medications, such as celecoxib.

Overexpression of p53 protein is an independent prognostic indicator in human endometrial carcinoma

The important role of the p53 gene in tumour progression and cellular response to DNA damage has prompted investigation of the clinical significance of alterations to this gene. We examined both p53 overexpression and mutation of the gene in endometrial carcinoma in order to evaluate the prognostic significance of these changes. Of 122 endometrial carcinomas, 33 (27%) showed overexpression of p53 in the nucleus and 66 (54%) in the cytoplasm. Mutation in the p53 gene was found in 16 (13%) cases but showed no significant association with patient survival. Nuclear p53 overexpression was associated with poor survival (48% vs 80% alive in negative tumours 5 years post operatively, P < 0.001). In contrast, cytoplasmic p53 overexpression was associated with better survival (85% vs 55%, P < 0.001). When patients were separated into prognostic subgroups according to established clinical markers, these associations remained significant within most subgroups examined. In multivariate analysis adjusted for surgical stage, histological grade and type and vascular invasion, both nuclear p53 overexpression [hazard ratio 4.9 (95% CI 1.3-17.6). P = 0.016] and cytoplasmic overexpression [0.25 (0.06-0.98), P = 0.047] were independent prognostic factors. Immunohistochemical assessment of p53 overexpression in the nucleus and cytoplasm could provide useful prognostic information for the management of patients with endometrial cancer.

Pulmonary agenesis as part of the VACTERL sequence

Pulmonary agenesis is an uncommon anomaly that has been reported in isolation and in association with other congenital defects. Such defects include oesophageal atresia, cardiac malformation, horseshoe kidney, and anal atresia. Over a period of three years we have seen five neonates or fetuses with unilateral agenesis of the lung. All the cases had three or more anomalies seen in the VACTERL sequence in addition to the pulmonary atresia. None had a tracheo-oesophageal fistula. None were the products of consanguineous marriages. There had been no recurrence of this range of defects in any of the families at the time of writing. We suggest that pulmonary agenesis may occur as an alternative to tracheo-oesophageal fistula in the VACTERL sequence.

Cephalosporin-induced immune neutropenia

Neutropenia is an occasional complication of treatment with cephalosporin antibiotics. This report describes two patients who had neutropenia while receiving high doses of cephalosporins. The neutrophil counts returned to normal after stopping the drug, and cephalosporin-dependent neutrophil antibodies were demonstrated in both cases, using the granulocyte immunofluorescence test. In one patient, the immune neutropenia appeared to be due to a drug adsorption mechanism similar to penicillin-induced haemolytic anaemia, while an immune complex mechanism may have been involved in the second patient.

The spectrum of cutaneous reactions associated with diltiazem: three cases and a review of the literature

BACKGROUND

Cutaneous reactions ranging from exanthems to severe adverse events have been reported in association with calcium channel blockers.

OBJECTIVE

Our purpose was to document cutaneous eruptions resulting from use of diltiazem.

METHODS

We describe three patients who experienced a cutaneous reaction (i.e., hypersensitivity syndrome reaction, pruritic exanthematous eruption, and acute generalized exanthematous pustulosis) possibly induced by diltiazem, summarize adverse reaction reports obtained from the Health Protection Branch, and review the literature on calcium channel blockers inducing cutaneous reactions.

RESULTS

Of the 315 cases of possible diltiazem-induced adverse reactions that were reported to the Health Protection Branch, 151 (48%) were cutaneous. The number of diltiazem-induced cutaneous events was significantly greater than those induced by either nifedipine or verapamil. However, no difference was found in the proportion of serious cutaneous adverse events to either of the three drugs.

CONCLUSION

Diltiazem has been associated with a variety of cutaneous reactions that appear to occur more frequently than with other calcium channel blockers.

Two novel alphaherpesviruses associated with fatal disseminated infections in Atlantic bottlenose dolphins

Two immature female bottlenose dolphins (Tursiops truncatus) were found stranded on the Atlantic coast of the USA. Necropsy and histopathologic examination of both dolphins demonstrated acute necrotizing lesions in multiple organ systems. Commonly seen in these lesions were cells with enlarged nuclei that contained single 4 to 6 microm diameter homogeneous eosinophilic inclusion bodies that were often surrounded by a clear halo. Ultrastructural examination revealed that intranuclear inclusions contained 90 to 110 nm diameter viral particles with electron-dense cores and hexagonal profiles. Viral particles were also present in the cytoplasm, and these were surrounded by variably electron-dense envelopes. Enveloped virions were 140 nm in diameter. Polymerase chain reactions targeting the DNA polymerase and terminase genes of herpesviruses were carried out on unfixed tissues of both animals, and analysis of the DNA products indicated the presence of two novel alphaherpesviruses. The gross, histologic, ultrastructural, and molecular genetic findings indicate disseminated herpesviral infections, and support the conclusion that the alphaherpesviruses caused the deaths of the two dolphins. This is the first report of disseminated herpesviral infection in cetaceans.

Osteodysplastic primordial dwarfism: report of a further case with manifestations similar to those of types I and III

We describe a male infant with microcephalic osteodysplastic primordial dwarfism. The clinical and radiological manifestations most closely resemble those of the patient described by Winter et al. to have manifestations overlapping with both osteodysplastic primordial dwarfism types I and III. The classification of the patient within the spectrum of osteodysplastic primordial dwarfism is discussed and the distinctive neuropathology documented.

An outbreak of multiply resistant Serratia marcescens: the importance of persistent carriage

An outbreak of multi-resistant Serratia marcescens involving 24 patients occurred in a bone marrow transplant and oncology unit, from September 1998 to June 1999, of whom 14 developed serious infection. This is the first such outbreak described in a BMT unit. All isolates demonstrated the same antimicrobial susceptibility pattern and were the same unusual serotype O21:K14. The antimicrobial susceptibility profile showed reduced susceptibility to ciprofloxacin, gentamicin and piperacillin-tazobactam. As the latter two antimicrobials are part of our empiric therapy for febrile neutropenia, they were substituted with meropenem and amikacin during the outbreak. Investigation revealed breaches in infection control practices. Subsequently, the outbreak was contained following implementation of strict infection control measures. A prominent feature of the outbreak was prolonged carriage in some patients. These patients may have acted as reservoirs for cross-infection. This report also indicates that patients who become colonised with Serratia marcescens may subsequently develop invasive infection during neutropenic periods.

Observer reliability in assessing placental maturity by histology

AIMS

To evaluate the ability of five experienced perinatal pathologists to assess placental maturity reliably by histology.

METHODS

Twenty four haematoxylin and eosin slides, six each from placentas of 27, 31, 35, and 39 weeks' gestation, were circulated to five pathologists on three separate occasions. The slides were labelled with the correct or incorrect gestational ages.

RESULTS

The mean absolute error over all 360 readings was 2.72 weeks. Only 54% of the slides were assessed within two weeks of the correct gestation. Pathologist tended to overestimate younger gestations and underestimate older gestations. Two, and possibly three, pathologist were influenced by the gestational age state on the label. One pathologist, who did not appear to be influenced by the label, was more accurate in diagnosing gestation of the placentas than other colleagues.

CONCLUSIONS

Experienced pathologists can have difficulty in assessing the villous maturity of placentas by histology. They can also be influenced by clinical information provided, such as gestational age. Other observer reliability studies must address the issue of the influence of labelled information on observer variation. A difference in maturation would have to be of a six week magnitude to have a chance of being detected by current methods. This may limit the value of the histological diagnosis of placental dysmaturity as a surrogate marker for uteroplacental ischaemia.

Blood component treatment: a retrospective audit in five major London hospitals

A retrospective audit of 200 transfusion episodes involving the use of platelets or fresh frozen plasma (FFP) was performed in five hospitals in London. It examined the currently used practices of transfusion and assessed the appropriateness of blood component treatment. It was necessary to search for an excess of case notes to provide a sufficient number of patients for review. In 61.5% of cases the reason for using the components was not stated. Inadequate documentation of the use of blood components occurred in 66% of cases. An accepted clinical indication for the use of components was evident in only 36% of the total; inappropriate use of FFP was particularly apparent. It is concluded that many aspects of transfusion practice need to be improved.

Metronidazole hypersensitivity

OBJECTIVE

To report a case of a possible hypersensitivity reaction induced by metronidazole.

CASE SUMMARY

An Asian woman with a history of recurrent vaginitis had previously developed localized erythema while on intravaginal metronidazole and nystatin. While receiving oral metronidazole for treatment of a current bacterial vaginosis, she developed chills, fever, generalized erythema, and a rash within 60 minutes of the first dose. Treatment with diphenhydramine was instituted. The following day while in the hospital, the patient's condition worsened; she experienced shortness of breath and increased edema of the extremities. Methylprednisolone was administered with diphenhydramine and her condition improved over the next 5 days. The patient's vaginitis was treated with gentian violet and she was discharged on a tapering dosage of prednisone.

DISCUSSION

Metronidazole-induced cutaneous reactions and systemic hypersensitivity reactions are reviewed. Alternatives to metronidazole and other potential cross-reactive drugs are suggested for the treatment of recurrent vaginitis.

CONCLUSIONS

Although the patient's initial reaction to metronidazole represented a rare event, written documentation and communication in the patient's native language may have prevented the subsequent severe hypersensitivity reaction.

The effect of mass on frequency

Two experiments are described where an apparent decrease in frequency was detected when the optical path was in the vicinity of a mass. In the first experiment the 21-centimeter absorption line from Taurus A was observed near occultation by the sun. In the second experiment the frequency of a portable cesium clock was compared with the frequency of a similar clock which transmits its signals from Cape Fear, North Carolina. A decrease of frequency of the received signals as a function of the distance between the two clocks was apparent. Several relevant observations (the red shift of lines from the sun, the Mossbauer determination of the gravitational red shift, and the cosmological red shif) are discussed in view of the present results. confirmation.

An explanation and the clinical significance of the failure of microcolumn tests to detect weak ABO and other antibodies

Shear forces are proposed to explain the failure of antiglobulin and 'neutral' (no antiglobulin) microcolumn tests at 37 degrees C to detect weak ABO incompatibilities and other weak antibodies, clearly detectable by spin-tube methods. These shear forces can be minimized in a microcolumn test using a biphasic centrifugation phase. Although this biphasic test is not suitable for routine use, it may be of use as an investigational method for reference laboratories. This failure of microcolumn test to detect weak ABO incompatibilities is of little clinical significance as the antibodies are dubiously active at 37 degrees C.

Dandy-Walker malformation (variant), cystic dysplastic kidneys, and hepatic fibrosis: a distinct entity or Meckel syndrome?

Dandy-Walker malformation is an unusual finding in Meckel syndrome, which characteristically presents with encephalocele, polydactyly, and cystic renal disease. We report on a family in which three nonviable brothers had Dandy-Walker malformations (variant) with associated enlarged cystic dysplastic kidneys and hepatic fibrosis. The consistent segregation of these abnormalities in all three sibs in the absence of polydactyly and encephalocele suggested the possibility of a distinct syndrome. The clinicopathological findings of the disorder are described and discussed in the context of the phenotypic spectrum of Meckel syndrome.

Anthropometric measurements in the second trimester fetus

Normal anthropometric measurements, of accepted value for clinicians and pathologists in the assessment of the dysmorphic neonate, have not in the past been available for the second trimester fetus, in which dysmorphic features are often more subtle and objective measurements most needed. In order to establish these values 19 anthropometric measurements, comparable to those published for the larger fetus and neonate, were recorded at autopsy on each of 260 overtly normal non-macerate singleton fetuses between 13 and 26 weeks gestation. Regression lines for each parameter, and growth ratios of potential value for description and assessment of dysmorphic features, were derived. The sex ratio was 1.27 and as there was no statistically significant sex difference for any of the 19 measurements chosen, the data was subsequently pooled. There were linear correlations between gestational age and each growth parameter, all but three exceeding 0.90. The linear correlations between pairs of growth parameter were higher than the correlations between gestational age and individual growth parameters. This suggests that growth parameter pairs, expressed as a ratio, are less affected by errors in gestational age estimation. Ratios enabling the dysmorphologist to more objectively assess common observations such as abnormalities of head shape, relationship between limb and trunk length and gross proportional relationships between major body segments were derived. Collected measurements were compared with established ultrasound reference ranges. While reference ranges for biparietal diameter and head circumference showed close concordance with those derived from ultrasound measurements, the abdominal circumference was consistently lower than that measured by ultrasound possibly because of differing trunk positions in utero compared with after death. The graphs and ratios derived in this study can be rapidly applied to confirm visual impressions at clinical examination and at autopsy.

Bone-marrow aspiration and trephine biopsy (1)

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Serious dermatologic reactions in children

Although serious reactions comprise only a small percentage of total adverse drug reactions, they are important in terms of morbidity and potential mortality. An update on serious dermatologic reactions in children is presented including serum sickness-like reactions due to cefaclor, hypersensitivity syndrome reactions (HSRs), and drug-induced pseudoporphyria. More detailed information on minocycline-induced reactions including drug-induced lupus and HSRs and lamotrigine-induced toxic epidermal necrolysis and Stevens-Johnson syndrome will be discussed.

Fungal keratitis in the Republic of Ireland

PurposeFungal keratitis is relatively rare in temperate climates with only one previous population-based study, which reported a minimum annual incidence of 0.32 per million population in the United Kingdom. We performed a nationwide study in the Republic of Ireland of cases over a 6-year period to establish the incidence, risk factors, treatment, and outcomes of fungal keratitis.Patients and methodsAll corneal scraping specimens positive for fungal species over a 6-year period were identified at the microbiology departments of the seven main ophthalmology units in the Republic of Ireland. Census data was used to establish national minimum annual incidence.ResultsForty-two eyes were treated for confirmed fungal keratitis during the 6-year period. This resulted in a minimum incidence of 1.53 cases per million population per year. Twenty-eight of 42 cases (67%) were due to filamentary fungi, with the most common species being Aspergillus. Pre-existing ocular surface disease was the most common risk factor constituting 42.9%; 26.2% underwent keratoplasty. No eyes underwent evisceration. Two eyes resulted in a level of vision of no perception of light. The mean LogMAR acuity in the remainder of cases was 0.89 with a range from -0.10 to 4.00.ConclusionThis study demonstrates a much higher minimum annual incidence than previously reported. The causative organism is highly related to risk factor. The range of visual outcomes remains broad in all subgroups. The wide range of outcomes and treatments used highlights the need for better evidence-based guidelines for fungal keratitis.

Examination of products of conception terminated after prenatal investigation

A large number of district general hospitals have access to diagnostic ultrasonography and other methods of prenatal diagnosis, resulting in an increased supply of freshly terminated malformed fetuses to general histopathology departments, and there is now more open discussion of malformation and greater concern over fetal wastage. General pathologists are therefore under greater pressure to produce complete and detailed descriptions of a wide range of often complex anomalies. The dismissal of specimens as "multiple congenital anomalies" is becoming increasingly unacceptable to couples who wish to embark on further pregnancies and to their medical attendants. As in other fields an understanding of the methods and terminology in clinical use and a consistent diagnostic approach should help pathologists to extract sufficient information for accurate counselling.