Parvovirus B19 Outbreak in Israel: Retrospective Molecular Analysis from 2010 to 2023

This study presents an analysis of the epidemiological trends of parvovirus B19 (B19V) in Israel from 2010 to 2023, with particular emphasis on the outbreak in 2023. The analysis utilized molecular diagnostic data from individual patients obtained at the Central Virology Laboratory. Between 2010 and 2022, 8.5% of PCR-tested samples were positive for B19V, whereas in 2023, this percentage surged to 31% of PCR-tested samples. Throughout the study period, annual cycles consistently peaked in early spring/summer, with the most recent prominent outbreak occurring in 2016. Predominantly, diagnoses were made in children and women aged 20-39. Despite the notable surge in 2023, over 80% of positive cases continued to be observed in children and young women, with a decrease in cases during winter months. Furthermore, genotype 1a of the virus remained the predominant strain circulating during the outbreak. In light of these circumstances, consideration should be given to implementing screening measures, particularly among high-risk groups such as pregnant women.

Recent HIV-1 infection in Israel 2017-2021: Evaluation of geenius and HIV-1/2 combo assays for identifying recent infection detected by Sedia assay and assessment of factors related to recent infection: Recent HIV-1 infection in Israel

BACKGROUND

Estimating HIV-1 recency of infection for incidence and local outbreaks detection usually involves specifically designed assays. Here, we established an approach to identify recent infections, estimate their rate, and assess potential risk factors.

METHODS

Randomly selected HIV-1 positive samples (n = 382) collected in 2017-2021 were tested by Sedia and compared to the results of Geenius recency algorithm and the S/CO values of the HIV-1/2 Combo assay. Using Geenius and Combo recency verdict, we assessed all cases diagnosed in 2017-2021. Related factors were further assessed.

RESULTS

While Geenius and Combo had a sensitivity of 65.9 % and 89.30 %, respectively, and specificity of 96 % and 90 %, respectively, compared to Sedia, higher concordance (97.2 %) and kappa (>0.9) were observed when the verdict of both assays together was compared to Sedia. Using this approach, 15.3 % (238/1548) of individuals diagnosed in 2017-2021 were defined as recently infected. In multivariate analysis, recent diagnosis was mainly associated with men who have sex with men (MSM) and with birthplace in Israel, Western/Central Europe, or North America.

CONCLUSIONS

Only 15.3 % of infections in 2017-2021, mainly in MSM and Israeli/Western countries-born individuals, were diagnosed early. Regular diagnostic assays have a potential to identify and monitor trends in recent infections.

Factors Associated with Virological Failure in First-Line Antiretroviral Therapy in Patients Diagnosed with HIV-1 between 2010 and 2018 in Israel

Despite the progress in contemporary antiretroviral therapy (ART) and the continuous changes in treatment guidelines, virological failure (VF) is still an ongoing concern. The goal of this study was to assess factors related to VF after first-line ART. A longitudinal cohort retrospective study of individuals on first-line ART diagnosed with HIV-1 in 2010-2018 and followed-up for a median of two years was conducted. Demographics, baseline and longitudinal CD4 counts, treatment regimens, adherence and VF were recorded. The Cox proportional hazards regression and mixed models were used. A cohort of 1130 patients were included. Overall, 80% were males and 62% were Israeli-born individuals. Compared to individuals diagnosed in 2010-2014, when treatment was initiated according to CD4 levels, those diagnosed in 2015-2018 were older and had lower baseline CD4 counts. VF was recorded in 66 (5.8%) patients. Diagnosis with CD4 <200 cells/mmᶟ with AIDS-defining conditions (HR = 2.75, 95%CI:1.52-4.97, p < 0.001) and non-integrase strand transfer inhibitor regimens (non-INSTI, HR = 1.80, 95%CI:1.01-3.24, p = 0.047) increased VF risk. No impact of baseline resistance was observed. We concluded that the early detection of HIV-1 infection and usage of INSTI-based regimens are recommended to reduce VF.

Dengue Types 1 and 3 Identified in Travelers Returning from Kathmandu, Nepal, during the October 2022 Outbreak Are Related to Strains Recently Identified in India

Phylogenetic analysis of dengue serotypes 1 and 3, which were diagnosed in travelers and Nepalese infected in Kathmandu during the October 2022 outbreak, revealed that both serotypes were clustered closest to the sequences sampled in India. This suggests both serotypes may have originated in India.

Emergence of genetically linked vaccine-originated poliovirus type 2 in the absence of oral polio vaccine, Jerusalem, April to July 2022

We report an emergence and increase in poliovirus type 2 detection via routine wastewater surveillance in three non-overlapping regions in the Jerusalem region, Israel, between April and July 2022. Sequencing showed genetic linkage among isolates and accumulation of mutations over time, with two isolates defined as vaccine-derived polioviruses (VDPV). This demonstrates the emergence and potential circulation of type 2 VDPV in a high-income country with high vaccine coverage and underscores the importance of routine wastewater surveillance during the polio eradication.

HIV-1 Circulating Recombinant Forms (CRFs) and Unique Recombinant Forms (URFs) in Israel, 2010-2018

Monitoring HIV-1 circulating recombinant forms (CRFs) and unique recombinant forms (URFs) is important for disease surveillance. Recombination may affect prevention efforts and interfere with the diagnosis and treatment of HIV-1 infection. Here, we characterized the epidemiology of HIV-1 CRFs and URFs in Israel. Partial pol sequences from treatment naïve patients diagnosed in 2010−2018 were assessed using the recombinant identification program (RIP), the recombinant detection program (RDP5), and using the maximum-likelihood phylogenetic method, using 410 reference sequences obtained from the Los Alamos database. CRFs and URFs were identified in 11% (213/1940) of all sequenced cases. The median age at diagnosis was 38 (30−47) years, 61% originated from Israel, and 82% were male. The most common were CRF02_AG (30.5%), CRF01_AE (16.9%), and the more complex forms CRF01_AE/CRF02_AG/A3 (10.8%) and B/F1 (7%). A significant increase in their overall proportion was observed in recent years (8.1% in 2010−2012, 20.3% in 2016−2018, p < 0.001). This increase was most prominent in individuals carrying CRF02_AG (2.5% in 2010−2015, 9.8% in 2016−2018, p < 0.001). Men who have sex with men (MSM) was the most common risk group; however, those infected with the secondary recombinant CRF02_AG/A6 were mainly injecting drug users (IDUs). The most common resistance mutations were K103N (5/213, 2.3%) and E138A (18/213, 8.5%) in the reverse transcriptase. Only E138A was more frequent in the recombinants compared with the classic subtypes and was significantly associated with a specific secondary CRF, CRF02_AG/A4. We concluded that CRFs and URFs were mainly detected in Israeli-born MSM and that an increase in the overall proportion of such HIV-1 sequences could be observed in more recent years.

Epidemiology and Transmitted HIV-1 Drug Resistance among Treatment-Naïve Individuals in Israel, 2010-2018

Despite the low prevalence of HIV-1 in Israel, continuous waves of immigration may have impacted the local epidemic. We characterized all people diagnosed with HIV-1 in Israel in 2010–2018. The demographics and clinical data of all individuals (n = 3639) newly diagnosed with HIV-1 were retrieved. Subtypes, transmitted drug-resistance mutations (TDRM), and phylogenetic relations, were determined in >50% of them. In 39.1%, HIV-1 transmission was through heterosexual contact; 34.3% were men who have sex with men (MSM); and 10.4% were people who inject drugs. Many (>65%) were immigrants. Israeli-born individuals were mostly (78.3%) MSM, whereas only 9% of those born in Sub-Saharan Africa (SSA), Eastern Europe and Central Asia (EEU/CA), were MSM. The proportion of individuals from SSA decreased through the years 2010–2018 (21.1% in 2010–2012; 16.8% in 2016–2018) whereas those from EEU/CA increased significantly (21% in 2010–2012; 27.8% in 2016–2018, p < 0.001). TDRM were identified in 12.1%; 3.7, 3.3 and 6.6% had protease inhibitors (PI), nucleotide reverse transcriptase inhibitors (NRTI), and non-nucleoside reverse transcriptase inhibitors (NNRTI) TDRM, respectively, with the overall proportion remaining stable in the studied years. None had integrase TDRM. Subtype B was present in 43.9%, subtype A in 25.2% (A6 in 22.8 and A1 in 2.4%) and subtype C in 17.1% of individuals. Most MSM had subtype B. Subtype C carriers formed small clusters (with one unexpected MSM cluster), A1 formed a cluster mainly of locally-born patients with NNRTI mutations, and A6 formed a looser cluster of individuals mainly from EEU. Israelis, <50 years old, carrying A1, had the highest risk for having TDRM. In conclusion, an increase in immigrants from EEU/CA and a decrease in those from SSA characterized the HIV-1 epidemic in 2010–2018. Baseline resistance testing should still be recommended to identify TDRM, and improve surveillance and care.

Identification of Hepatitis E Virus Genotypes 3 and 7 in Israel: A Public Health Concern?

Background: Hepatitis E (HEV) is an emerging cause of viral hepatitis worldwide. Swine carrying hepatitis E genotype 3 (HEV-3) are responsible for the majority of chronic viral hepatitis cases in developed countries. Recently, genotype 7 (HEV-7), isolated from a dromedary camel in the United Arab Emirates, was also associated with chronic viral hepatitis in a transplant recipient. In Israel, chronic HEV infection has not yet been reported, although HEV seroprevalence in humans is ~10%. Camels and swine are >65% seropositive. Here we report on the isolation and characterization of HEV from local camels and swine. Methods: Sera from camels (n = 142), feces from swine (n = 18) and blood from patients suspected of hepatitis E (n = 101) were collected during 2017–2020 and used to detect and characterize HEV sequences. Results: HEV-3 isolated from local swine and the camel-derived HEV-7 sequence were highly similar to HEV-3f and HEV-7 sequences (88.2% and 86.4%, respectively) related to viral hepatitis. The deduced amino acid sequences of both isolates were also highly conserved (>98%). Two patients were HEV-RNA positive; acute HEV-1 infection could be confirmed in one of them. Discussion: The absence of any reported HEV-3 and HEV-7 infection in humans remains puzzling, especially considering the reported seroprevalence rates, the similarity between HEV sequences related to chronic hepatitis and the HEV genotypes identified in swine and camels in Israel.

HIV-1 infection among women in Israel, 2010-2018

INTRODUCTION

Although women comprise 33% of the HIV-1-carriers in Israel, they have not previously been considered a risk group requiring special attention. Immigration waves from countries in Africa and in East Europe may have changed the local landscape of women diagnosed with HIV-1. Here, we aimed to assess viral and demographic characteristics of HIV-1-positive women identified in Israel between 2010 and 2018.

METHODS

All > 16 year-old, HIV-1-infected women, diagnosed in Israel in 2010-2018, (n = 763) registered in the National HIV reference laboratory were included in this cross-sectional study. Demographic and clinical characteristics were extracted from the database. Viral subtypes and transmitted drug resistance mutations (TDRM) were determined in 337 (44.2%) randomly selected samples collected from treatment-naive women.

RESULTS

Median age at diagnosis was 38 years. Most (73.3%) women were immigrants from the former Soviet Union (FSU) (41.2%, 314) or sub-Saharan Africa (SSA) (32.2%, 246) and carried subtype A (79.7%) or C (90.3%), respectively. Only 11.4% (87) were Israeli-born women. Over the years, the prevalence of women from SSA decreased while that of women from FSU increased significantly (p < 0.001). The median CD4⁺ cell count was 263 cells/mm³, and higher (391 cells/mm³) in Israeli-born women. TDRM were identified in 10.4% of the tested samples; 1.8, 3 and 7.1% had protease inhibitors (PI), nucleotide reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) TDRM, respectively. The prevalence of women with NNRTI TDRM significantly increased from 4.9% in 2010-2012 to 13.3% in 2016-2018. Israeli-born women had the highest prevalence (16.3%) of NNRTI TDRM (p = 0.014). NRTI A62 (5.6%), NNRTI E138 and K103 (5.6 and 4.2%, respectively) were the most prominent mutated sites.

CONCLUSIONS

Most HIV-1-positive women diagnosed in Israel in 2010-2018 were immigrants, with the relative ratio of FSU immigrants increasing in recent years. The high proportion of women diagnosed with resistance mutations, particularly, the yearly increase in the frequency of NNRTI mutations, support the national policy of resistance testing at baseline.

Hepatitis E in pigs in Israel: seroprevalence, molecular characterisation and potential impact on humans

IntroductionThe zoonotic hepatitis E virus (HEV) genotype 3 (HEV-G3) has become a common cause of acute and chronic hepatitis among humans worldwide. In Israel, while HEV-3 sequences have previously been detected in sewage, only the non-zoonotic HEV-G1 genotype has been found in samples from human patients.AimIn this pilot study, we aimed to assess the status of HEV in a sample of the swine population and among swine farm workers in Israel.MethodsPig blood (n = 141) and faecal samples (n = 39), pig farm sewage samples (n = 8) and blood from farm workers (n = 24) were collected between February 2016 and October 2017. Anti-HEV IgG was detected using the Wantai assay. HEV RNA was analysed with the RealStar HEV kit. HEV open reading frame 1 fragments amplified from representative HEV RNA-positive samples were used for phylogenetic analysis.ResultsOverall prevalence of HEV antibodies in pigs was 75.9% (107/141). HEV RNA was detected in plasma (2.1%, 3/141), faecal (22.8%, 18/79) and pig sewage (4/8) samples. Pig and sewage-derived viral sequences clustered with previously identified human sewage HEV-G3 sequences. Most pig farms workers (23 of 24) were HEV-seropositive; none was viraemic or reported previous clinical signs.ConclusionsThis study showed that domestic pigs in Israel are infected with HEV-G3. The high HEV seropositivity of the farm workers together with the previous identification of this virus in human sewage suggests circulation to humans. The clinical impact of these findings on public health should be further explored.

HIV-1/2 screening in blood centers: implementing a two-step serological screening assay approach to reduce donor deferral

BACKGROUND

Screening blood donations for human immunodeficiency virus 1/2 (HIV-1/2) infection in blood centers is often done with a highly sensitive 3rd-generation immunoassay which may cause false-positive results. Donations found repeatedly reactive (RR) are discarded regardless of negative HIV-1/2 nucleic acid testing (NAT) and confirmatory assays results. These donors are notified and deferred if RR in a subsequent donation. We evaluated the introduction of a secondary 4th-generation serological assay to the overall algorithm performance.

METHODS

All donations collected between January 2016 and May 2018 (574,338) were screened using 3rd-generation immunoassay (PRISM HIV O Plus) and NAT (Procleix Ultrio/Ultrio Elite). Serology RR donations were tested with 4th-generation Architect HIV Ag/Ab Combo and Vidas HIV Duo Ultra and a confirmatory assay (Geenius HIV-1/2).

RESULTS

The two 4th-generation assays found that 86% (179/209 on Architect) and 94% (182/193 on Vidas) of the 3rd-generation immunoassay RR were negative for HIV-1/2, which were also negative by confirmatory assay. Only 14% (30/209 on Architect) and 6% (11/193 on Vidas) that were 3rd-generation HIV-1/2 RR required confirmation, of which eight donors were confirmed as HIV positive. The probability of missing an HIV-1 infected donor by this algorithm is one in a million RR cases.

CONCLUSION

The introduction of a two-step serological screening algorithm in blood centers whereby 4th-generation assay will be performed for all 3rd-generation RR blood donors will reduce the number of donations requiring confirmation, save time and money, and most importantly, reduce the number of discarded blood donations and allow re-entry processes.

Diagnosis of HIV-1 infection: Performance of Xpert Qual and Geenius supplemental assays in fourth generation ELISA-reactive samples

BACKGROUND

Architect (AR) and Vidas (VD) fourth generation HIV screening immunoassays, which identify early stages of HIV infections, could have false positive results especially at low signal/cutoff (S/C) AR values. Geenius HIV1/2 (GS) is a specific confirmation line immunoassay that is not highly sensitive to early HIV infections. An HIV-1 RNA assay may better detect such infections.

OBJECTIVES

To evaluate all AR-VD reactive samples with GS results, and to assess Xpert Qual HIV-1 RNA assay (XQ) as an alternative to GS, in the first low S/C AR-VD-reactive samples from a tested individual.

STUDY DESIGN

First AR-VD-reactive-GS-tested results from all individuals with resolved HIV status, collected between March 2015 and March 2017 (n = 749), were retrospectively assessed. Samples with AR-VD-reactive-GS-discordant results and those with low S/C AR-VD-reactive results, were tested by XQ. Receiver operating characteristic (ROC) analysis of GS and XQ sensitivity/specificity was performed.

RESULTS

Overall, 94.1% (705/749) of AR-VD-reactive results were true HIV-1 positive. All samples with <3 S/C AR values were false positive. XQ resolved all first samples with AR-VD-reactive-GS-discordant results. The diagnostic accuracy of XQ in low (≤33 S/C) AR-VD-reactive samples was better than that of GS (97.6%, 81/83 versus 73.5%, 61/83, p < 0.01). ROC analysis for low S/C AR samples was optimal for pooled XQ and GS results.

CONCLUSIONS

Incorporating XQ in the current screening algorithm for the first AR-VD-reactive-GS-discordant samples may significantly reduce overall turn-around time of HIV-1 diagnosis.

Comparison between next-generation and Sanger-based sequencing for the detection of transmitted drug-resistance mutations among recently infected HIV-1 patients in Israel, 2000-2014

INTRODUCTION

Transmitted drug-resistance mutations (TDRM) may hamper successful anti-HIV-1 therapy and impact future control of the HIV-1 epidemic. Recently infected, therapy-naïve individuals are best suited for surveillance of such TDRM. In this study, TDRM, detected by next-generation sequencing (NGS) were compared to those identified by Sanger-based population sequencing (SBS) in recently infected HIV-1 patients.

METHODS

Historical samples from 80 recently infected HIV-1 patients, diagnosed between 2000 and 2014, were analysed by MiSeq (NGS) and ABI (SBS). DeepChek-HIV (ABL) was used for interpretation of the results.

RESULTS

Most patients were males (80%); Men who have sex with men (MSM) was the major transmission group (58.8%). Overall, TDRM were detected in 31.3% of patients by NGS and 8.8% by SBS, with SBS TDRM restricted to persons infected with subtype B. All SBS-detected TDRM were identified by NGS. The prevalence of TDRM impacting protease inhibitors (PI), nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitors (NNRTI) was 11.3, 26.2 7.5%, respectively, in NGS analyses and 0, 3.8 and 5%, respectively, in SBS analyses. More patients with NGS and SBS TDRM were identified in 2008-2014 (37.2% or 13.9%, respectively) compared to 2000-2007 (24.3% or 2.7%, respectively), and a significantly greater number of these patients had multiple NGS TDRM. The most abundant, albeit, minor-frequency RT TDRM, were the K65R and D67N, while K103N, M184V and T215S were high-frequency mutations. Minor TDRM did not become a major variant in later samples and did not hinder successful treatment.

CONCLUSIONS

NGS can replace SBS for mutation detection and allows for the detection of low-frequency TDRM not identified by SBS. Although rates of TDRM in Israel continued to increase from 2000 to 2014, minor TDRM did not become major species. The need for ongoing surveillance of low-frequency TDRM should be revisited in a larger study.

Evaluation of Xpert HIV-1 Qual assay for resolution of HIV-1 infection in samples with negative or indeterminate Geenius HIV-1/2 results

BACKGROUND

Diagnosis of HIV infection is a multistage algorithm. Following screening with 4(th) generation combination immunoassay, confirmation of HIV infection is performed with an antibody assay that differentiates HIV-1 from HIV-2 infection. In the newly updated algorithm, samples that are nonreactive or indeterminate in the differentiation assay are to be tested with an HIV-1 nucleic acid amplification (NAAT) test for resolution. Xpert HIV-1 Qual is a new NAAT assay approved for the identification of HIV infection in whole and dried blood.

OBJECTIVES

To assess the performance of Xpert HIV-1 Qual supplementary assay in resolving the clinical status of serum samples reactive by 4(th) generation immunoassays and indeterminate or negative by Geenius HIV-1/2 confirmatory assay.

STUDY DESIGN

In a retrospective study, samples from 97 individuals for whom the true HIV-1 status was already known (by follow-up samples) and which were negative or indeterminate by HIV-1/2 Geenius assay were tested with Xpert Qual HIV-1 assay.

RESULTS

Xpert Qual assay correctly classified all 97 samples from HIV-1 positive (n=49) and negative (n=48) individuals. The sensitivity and specificity of Xpert Qual when using the true HIV status as a reference were 100% (92.7-100% at 95% confidence interval [CI] and 92.6-100% at 95% CI, respectively).

CONCLUSIONS

Applying Xpert Qual HIV-1 assay in the new HIV multi-stage diagnostic algorithm correctly classified 100% of HIV-1 infections including 49 from HIV-1 carriers who have not yet seroconverted. With this assay the total time required for acute HIV diagnosis could be significantly reduced.

Prevalence of hepatitis E virus antibodies, Israel, 2009-2010

We investigated prevalence of hepatitis E virus in a sample of the population of Israel. The overall seroprevalence of antibodies to the virus was 10.6% (95% CI 8.4%-13.0%); age-adjusted prevalence was 7.6%. Seropositivity was associated with age, Arab ethnicity, low socioeconomic status, and birth in Africa, Asia, or the former Soviet Union.

Microvascular reconstruction and tracheotomy are significant determinants of resource utilization in head and neck surgery

BACKGROUND

Successful "critical pathway" design and implementation are dependent on appropriate patient stratification according to those factors that are primary determinants of resource utilization.

OBJECTIVES

To test the validity of our previously reported critical pathway design and to determine whether tracheotomy and microvascular reconstruction (MR) are primary determinants of resource utilization.

DESIGN

Cost-effectiveness analysis.

SETTING

Tertiary referral academic institution.

METHODS

Retrospective analysis of data from 133 head and neck surgery cases in which the treatment regimen was based on critical pathways over a 26-month period.

OUTCOME MEASURES

Length of stay and total patient charges were used as indices of resource utilization. One-way analysis of variance and t tests were used for statistical analysis of significance.

RESULTS

Ninety patients (67.7%) underwent MR; 43 (32. 3%) did not. Seventy-five patients (56.4%) underwent tracheotomy; 58 (43.6%) did not. Four patient groups were constructed in decreasing order of complexity as follows: group 1, patients who underwent both tracheotomy and MR (n = 58); group 2, patients who underwent MR alone (n = 32); group 3, patients who underwent tracheotomy alone (n = 17); and group 4, patients who did not undergo either procedure (n = 26). Both tracheotomy and MR were found to be independent determinants of resource utilization and were additive when both were present. The length of stay varied from 8.4 days (in patients who underwent both procedures) to 6.7 days (in patients who did not undergo either procedure), with intermediate values in cases in which only 1 procedure was performed. The total charges varied in a similar manner from a high of $33,371 to a low of $19,994. Subanalysis with respect to intensive care unit, ward, and operating room charges showed a similar stratification.

CONCLUSION

Tracheotomy and MR are both significant determinants of charges and length of stay in head and neck surgery cases and must be considered in the design of strategies to promote efficient resource utilization.

Sildenafil for psychotropic-induced sexual dysfunction in 31 women and 61 men

Ninety-two outpatients (31 women, 61 men) who were treated with oral sildenafil for psychotropic-induced sexual dysfunction (PISD) completed ratings of their sexual functioning pre- and posttreatment. Both women and men reported significant improvements (p = .001) in all domains of sexual functioning, with 88% reporting improvement in overall sexual satisfaction. Significant improvements were reported regardless of psychotropic medication type. However, patients taking selective serotonin re-uptake inhibitors reported less improvement in arousal, libido, and overall sexual satisfaction than did other patients, whereas patients taking benzodiazepines reported significantly more improvement in libido and overall sexual satisfaction. Oral sildenafil may be an effective treatment for PISD.

Acid/pepsin promotion of carcinogenesis in the hamster cheek pouch

OBJECTIVE

While clinical observation has suggested an association between gastroesophageal reflux and laryngeal carcinoma, the nature of this relationship has yet to be defined. The purpose of this study is to determine the carcinogenic potential of acid and pepsin mixtures in the hamster cheek pouch animal model.

DESIGN

A blinded intervention study.

SUBJECTS

One hundred male Syrian hamsters aged approximately 5 weeks.

INTERVENTIONS

A control group of 20 hamsters received application of the carcinogen 9,10-dimethyl-1,2-henzanthracene (DMBA) to their cheek pouch mucosa. One experimental group (n = 20) received applications of DMBA plus hydrochloric acid, and another (n = 20) received DMBA plus an acid and pepsin solution. Latency to squamous cell tumor production, size of tumors, and numbers of tumors were compared among groups.

RESULTS

Latency to tumor production and size of tumor were similar among groups, with both experimental and control groups developing tumors of comparable size after 12 weeks of chemical application. However, the number of tumors produced was significantly higher in the DMBA/acid and DMBA/acid/ pepsin groups than in the DMBA only group at 18 weeks, with 23, 27, and 10 tumors in these groups, respectively (P<.02). Likewise, a cumulative dysplasia score was different among groups at 18 weeks with the DMBA/acid and DMBA/acid/pepsin groups scoring higher degrees of dysplasia than the DMBA only group.

CONCLUSION

These results suggest that application of acid and acid/pepsin mixtures may promote experimental carcinogenesis in the hamster cheek pouch.

Lemierre syndrome: a complication of acute pharyngitis

Lemierre syndrome, otherwise known as postanginal sepsis or necrobacillosis, is an illness that originates as an acute pharyngitis or tonsillitis which progresses to sepsis, usually fusobacterial, due to suppurative thrombophlebitis of the internal jugular vein. Septic thromboemboli then seed various organs, resulting in multiple organ system pathology, most commonly affecting pulmonary and hepatic systems and joints. Although rare in the age of antibiotics, this disease typically affects previously healthy adolescents with varied clinical manifestations depending upon organ system involvement (A. Lemierre, Lancet March (1936) 701-703; J. Barker, H.T. Winer-Muram, S. Grey, Southern Med. J. 89 (1996) 1021-1023). Prompt diagnosis based on clinical presentation, radiologic findings, particularly CT scanning with contrast and a high index of suspicion, is necessary in order to institute often life saving therapy (J. Barker, H.T. Winer-Muram, S. Grey, Southern Med. J. 89 (1996) 1021-1023). We will present two cases of Lemierre syndrome, review it's clinical presentation, anatomic considerations, particularly it's relationship to the parapharyngeal space, radiographic findings, potential life threatening complications and finally, a unique approach to therapy.

Tumoral calcinosis of the temporomandibular joint: CT and MR findings

In this article, the CT, three-dimensional CT, and MR findings are reviewed in a 59-year-old woman with tumoral calcinosis involving the temporomandibular joint.

A rationale for gene targeting in glaucoma therapy

One of the mainstays of glaucoma treatment is the use of drugs that decrease the secretion of aqueous humor fluid from the ciliary epithelium. Unfortunately, many currently available drugs that decrease aqueous humor production such as beta-adrenergic antagonists, may cause serious systemic side effects such as cardiac arrhythmias and arrest, pulmonary dysfunction, and CNS side effects such as decreased libido and depression. Efforts to develop effective aqueous suppressants that offer decreased morbidity and mortality in comparison to those currently available will likely rely on the ability to alter the function of specific cellular events which underlie aqueous humor production by the ciliary epithelium. However, the secretory process which results in aqueous humor production is incompletely understood and the identification of precise cellular mechanisms which underlie this process remain to be established. We will present a rationale for genetic approaches to regulate gene expression so that aqueous humor production may be specifically targeted in glaucoma patients. Techniques of gene transfer including homologous exchange recombination, and expression of antisense genes, will be discussed.

Purinergic receptors in ocular ciliary epithelial cells

Adenosine and ATP have been shown to activate separate cell surface purinergic receptors which have been designated P1 for adenosine and P2 for ATP. The pharmacological characterization of P1 and P2 purinergic receptor-mediated signal transduction has been performed in cultured cell lines of the ciliary epithelium. In ODM Clone-2, a cell line derived from human nonpigmented ciliary epithelium (NPE) and in a clone derived from bovine pigmented ciliary epithelium (PE), we observed that adenosine inhibits adenylate cyclase activity at high potency (nM) and stimulates adenylate cyclase activity at low potency (microM) suggesting the presence of P1 subtypes on these cell membranes. The selective agonist cyclopentyladenosine (CPA) was effective at inhibiting forskolin-stimulated adenylate cyclase in these cells. The IC50 for CPA in both NPE and PE was approximately 1 nM in the absence, and 11 nM in the presence of 3-isobutyl-1-methylxanthine (IBMX). In NPE, the selective agonist 2-[p-(2-carboxyethyl)phenethylamino]-5'-N-ethylcarboxamido adenosine (CGS 21680) stimulated adenylyl cyclase with an EC50 of 11 +/- 4 nM in the presence of 4-(3-butoxy-4-methyoxybenzyl)-2-imidazolidinone (RO-20-1724), a phosphodiesterase inhibitor devoid of adenosine receptor antagonism, and 61 +/- 8 microM in the presence of IBMX. In PE cells, EC50 value of RO-20-1724 was 19 +/- 5 nM (n = 3). The characterization of P2 receptors based upon the ability of ATP and its related analogues to stimulate inositol phosphate production reveal the presence of a putative P2u receptor in both cell types.

Post-parotidectomy fistula

Today parotidectomy is a common, safe surgical procedure. With the increase in the number of parotidectomies being performed there have been many reviews of both the immediate and delayed operative complications. Postoperative salivary fistula, although a common occurrence, is usually glossed over or barely mentioned in most reviews. The present study reviews the parotid experience at a major teaching hospital, The Wellesley Hospital, University of Toronto, over a 10-year period. This information was used to draw general conclusions concerning the incidence, etiology and treatment of salivary fistulas as well as their prevention.