Look, but to the left: A rare case of gallbladder sinistroposition and comprehensive literature review

Left-sided gallbladder (LSGB) is a rare anatomic variation that, while benign in the context of its transposition, is of significant intraoperative importance. Due to its association with other anatomic anomalies involving key structures in the hepatobiliary system, discovering it intraoperatively as opposed to preoperatively suddenly increases the difficulty of a gallbladder procedure.

1)

Left-sided gallbladder (LSGB) is a rare anatomic variation that, while benign in the context of its transposition, is of significant intraoperative importance.

2)

Although laparoscopic cholecystectomy of a LSGB is safe, it is associated with higher risk of complications such as common bile duct injury.

3)

Most cases of a LSGB are diagnosed intraoperatively, and this sudden discovery during the procedure can increase the difficulty, duration, and stress of the procedure due to the other potential anatomic anomalies that LSGB is associated with in the hepatobiliary system.

AVALIAÇÃO DA INTEGRIDADE DA BARREIRA ENDOTELIAL E SUA RELAÇÃO COM AS MANIFESTAÇÕES CLÍNICAS E LABORATORIAIS NA COVID-19

Objetivos

Os mecanismos fisiopatológicos que determinam a gravidade da Covid-19 estão associados a ativação da hemostasia e da imunidade inata, em um processo coletivamente referido como imunotrombose, e que envolve ativação plaquetária, geração de NETs (do inglês, Nucleo extracelular traps), expressão de fator tecidual, ativação do complemento e ativação endotelial. Um elemento importante da ativação endotelial é a quebra da barreira endotelial (BE), que ocorre para facilitar o acesso de leucócitos aos tecidos, onde contribuem para erradicação dos patógenos. No entanto, a avaliação da integridade da BE é desafiadora, exigindo o uso de modelos celulares. O objetivo desse estudo foi avaliar o efeito do soro de pacientes com Covid-19 sobre a integridade da BE em monocamadas de células endoteliais, e sua correlação com características clínicas da doença.

Materiais e métodos

A população do estudo consistiu em 30 pacientes com Covid-19 que apresentavam comprometimento pulmonar confirmado por tomografia de tórax, e necessidade de internação hospitalar por hipoxemia e 30 controles saudáveis pareados por sexo e idade. Os pacientes recrutados fizeram parte de um estudo clínico (REBEC: U1111-1250-1843), e as amostras utilizadas nesta avaliação foram obtidas no momento da internação, antes de qualquer intervenção. Monocamadas de células endoteliais de duas fontes (HUVECs: células de cordão umbilical; HULECs: células endoteliais pulmonares) foram estimuladas com soro de pacientes e indivíduos saudáveis (diluição 15% em meio de cultura) e a integridade da BE foi avaliada por um sensor de impedância celular (ECIS; Eletric Cell-substrate Impedance Sensing System) continuamente por 36 horas. Biomarcadores de gravidade e relacionados à ativação da hemostasia foram avaliados por kits comerciais. Dados clínicos foram obtidos a partir dos prontuários digitais.

Resultados

O soro de pacientes com Covid-19 induziu quebra de BE significativamente mais acentuada que o de indivíduos saudáveis em HUVECs nos tempos 15 min (p < 0,01); 30 min (p ≤ 0,001); 1h (p ≤ 0,0001); 2h (p ≤ 0,0001); 3h (p ≤ 0,0001); 4h (p ≤ 0,01) e 5h (p ≤ 0,05). Estes resultados foram confirmados no modelo de células endoteliais pulmonares (HULECs). A magnitude da quebra apresentou correlação significativa com desfechos clínicos relevantes como tempo de internação total (R_S até 0.57) e tempo de UTI (R_S = 0,47). Em relação a biomarcadores de interesse na Covid-19, a quebra da BE apresentou correlação significativa com neutrofilia, relação neutrófilo/linfócito, fator de Von Willebrand, fatores IX e XI, fibrinogênio, D-dímero e uPAR (Receptor de Uroquinase).

Discussão

Através de um método considerado padrão-ouro para avaliação in vitro da integridade da BE nós demonstramos que componentes presentes no soro de pacientes com Covid-19 são capazes de promover a quebra da BE, e que a magnitude deste processo está relacionada à gravidade desta doença. A correlação com outros marcadores inflamatórios corrobora a conexão entre os mecanismos envolvidos na imunotrombose em pacientes com Covid-19.

Conclusão

nossos resultados apontam a quebra da BE como um alvo terapêutico atrativo nestes pacientes.

AVALIAÇÃO DOS NÍVEIS CIRCULANTES DE MEDIADORES DA INTEGRIDADE DA BARREIRA ENDOTELIAL NA COVID-19 E SUA RELAÇÃO COM A ATIVAÇÃO DA HEMOSTASIA

Objetivos

a imunotrombose consiste no processo que envolve a ativação concomitante da imunidade inata, hemostasia e endotélio como parte da resposta a patógenos, e vem sendo colocada no centro da fisiopatologia da Covid-19. Um elemento menos explorado da imunotrombose é a ruptura da barreira endotelial (BE), que permite o acesso dos leucócitos aos tecidos inflamados. Entre os reguladores da integridade da BE destacam-se as vias que envolvem a angiopoietina (Ang) 1 e 2 e seu receptor Tie2, e a via do VEGF-A/VE-caderina (VEC). Além deste papel, foi recentemente demonstrado que a ativação da via Ang/Tie2 inibe a ativação endotelial e a expressão de fator tecidual, estabilizando o endotélio no estado quiescente. Neste estudo determinamos os níveis circulantes de mediadores da integridade da BE na Covid-19, e exploramos sua associação com a gravidade da doença, assim como com a ativação da hemostasia através de um painel abrangente de biomarcadores.

Materiais e métodos

as amostras foram obtidas de 30 pacientes internados por Covid-19 devido à hipoxemia e achados tomográficos típicos, e recrutados para um estudo clínico (REBEC: U1111-1250-1843). As amostras foram coletadas em até 24h do diagnóstico, antes de qualquer intervenção terapêutica. Os níveis de reguladores da BE foram medidos por métodos imunológicos (Elisa ou multiplex), e o de biomarcadores da hemostasia por kits comerciais específicos. Um grupo de 30 indivíduos saudáveis pareados por idade e sexo foram utilizados como controle. Dados clínicos e laboratoriais foram obtidos dos prontuários digitais.

Resultados

o tempo médio de internação foi de 12,9 ± 9,8 dias, e 12 pacientes (40%) necessitaram de UTI. O dímero D médio foi de 3.609 ± 14.440 ng/mL. Os níveis circulantes de todos reguladores da integridade da BE encontraram-se aumentados em pacientes, quando comparado com controles (Ang1: 463.2 ± 194.6 vs 237.4 ± 104.9 pg/mL, p < 0.0001; Ang2: 1.926 (1.275-3.134) vs 1.215 (9-1.444) pg/mL, p < 0.0001; Tie2: 10.753 ± 2.377 vs 8.603 ± 1.851 pg/mL, p < 0.0001 e VEGF-A: 94.7 (73.4-116.0) vs 45.9 (39.7-57.0), p < 0.0001. Além disso, os níveis de alguns destes reguladores se associaram significativamente a desfechos de relevância clínica, a saber: (i) extensão da lesão pulmonar na tomografia: Ang2 e VEGF-A; (ii) tempo de internação em UTI: VEGF-A. Interessantemente, observamos correlações consistentes e significativas entre os níveis de reguladores da BE a proteínas envolvidas na ativação da hemostasia (fibrinogênio, VWF: Ag, uPAR, PAI-1 e P-selectina).

Discussão

o interesse no estudo de reguladores da integridade da BE na Covid-19 já se justifica pelo fato de a doença envolver tanto o comprometimento da barreira alvéolo-capilar quanto a ativação da angiogênese, como demonstrado por outros autores. Nossos resultados reforçam a relevância destas vias através da associação observada com desfechos clínicos. Além disso, os resultados mostram pela primeira vez uma associação entre mediadores da integridade da BE e um painel amplo de biomarcadores da ativação da hemostasia, sugerindo um crosstalk entre estas vias na Covid-19, como demonstrado recentemente no contexto da sepse.

Conclusões

nossos resultados apontam que a via Ang/Tie2 deve ser considerada um alvo terapêutico atrativo na Covid-19, por representar um elemento central da imunotrombose nestes pacientes.

AVALIAÇÃO DOS NÍVEIS DE MARCADORES DA VIA HEME/HEMOPEXINA/HEME-OXIGENASE 1 E SUA ASSOCIAÇÃO COM PARÂMETROS CLÍNICOS E LABORATORIAIS NA COVID-19

Objetivos

Material e métodos

Resultados

Discussão

Conclusão

Idiopathic myointimal hyperplasia of the mesenteric veins

Idiopathic myointimal hyperplasia of the mesenteric veins (IMHMV) is caused by proliferation of smooth muscle cells in the wall of small mesenteric veins and venules with accumulation of a proteoglycan matrix leading to a non-thrombotic, non-inflammatory venous occlusion resulting in venous ischemia. IMHMV is a rare and poorly understood disease, with <20 case reports in the literature. The purpose of this report is to describe the case of a 63-year-old man who presented with this condition that resulted in colonic ischemia necessitating surgical resection. The cause of IMHMV in this patient was attributed to a Chinese herbal supplement used for degenerative osteoarthritis of the knees. A brief review of the literature is provided along with the case report.

Arterial Thrombus in a Protein C Deficient Patient

Protein C is a Vitamin K derivative that plays an essential role in anticoagulation. Protein C deactivates clotting factors Va and VIIIa; therefore, a deficiency in this protein leads to over expression and activation of these factors and essentially a hypercoagulable, prothrombotic state. Although studies have shown that the cardinal manifestation of protein C deficiency is venous thromboembolism, we present a case of a patient in his third decade with a myocardial infarction on a background of protein C deficiency and minimal cardiovascular risk factors. Similar cases of patients presenting with arterial thrombus on background of protein C deficiency have been reported; therefore, it is imperative to acknowledge protein C deficiency as a possible cause of acute, premature myocardial infarctions in young patients with minimal or no risk for cardiovascular disease.

Thoracic disc herniation: Surgical treatment

Thoracic disc herniation is rare and mainly occurs between T8 and L1. The herniation is calcified in 40% of cases and is labeled as giant when it occupies more than 40% of the spinal canal. A surgical procedure is indicated when the patient has severe back pain, stubborn intercostal neuralgia or neurological deficits. Selection of the surgical approach is essential. Mid-line calcified hernias are approached from a transthoracic incision, while lateralized soft hernias can be approached from a posterolateral incision. The complication rate for transthoracic approaches is higher than that of posterolateral approaches; however, the former are performed in more complex herniation cases. The thoracoscopic approach is less invasive but has a lengthy learning curve. Retropleural mini-thoracotomy is a potential compromise solution. Fusion is recommended in cases of multilevel herniation, herniation in the context of Scheuermann's disease, when more than 50% bone is resected from the vertebral body, in patients with preoperative back pain or herniation at the thoracolumbar junction. Along with complications specific to the surgical approach, the surgical risks are neurological worsening, dural breach and subarachnoid-pleural fistulas. Giant calcified herniated discs are the largest contributor to myelopathy, intradural extension and postoperative complications. Some of the technical means that can be used to prevent complications are explored, along with how to address these complications.

A podoscopic and descriptive study of foot deformities in patients with Down syndrome

INTRODUCTION

Subjects with Down syndrome (DS) are known to be affected by various foot deformities. Despite the fact that some of these deformities have been reported in the literature, a more comprehensive description would be of benefit. The aim of this study is to investigate the prevalence of known foot deformities in patients with DS and of other previously non-described foot anomalies in this population.

HYPOTHESIS

Subjects with DS have an increased prevalence of foot deformities compared to control subjects.

METHODS

Fifty-five subjects with DS (age: 14.6±7.4 years) had undergone podiatric clinical and podoscopic examinations to study their main foot deformities and their footprints, respectively. The results of these examinations were compared to those of an age-matched asymptomatic control group of fifty-three subjects (age: 13.4±11.2 years).

RESULTS

Significantly more prevalent foot deformities were found in the DS group: hallux valgus (36.4%), syndactyly between the 2nd and 3rd toes (9.1%), grade II pes planus (39.1%) and grade III pes planus (30%). Moreover, joint laxity (43.6%) was significantly more prevalent in the DS group. Furthermore, the presence of an increased space between the 1st and 2nd toes in patients with DS and its prevalence (73.6%) were described for the first time. A multivariate analysis revealed a significant relationship between the presence of joint laxity and flatfoot in only the control but not the DS group. Other foot deformities were found to be consistently more frequent in the DS population but not significantly higher than the control group.

DISCUSSION

Although subjects with DS had significantly greater joint laxity and BMI compared to the control group, neither of these factors was found to be related to the increased prevalence of flatfoot in DS patients.

LEVEL OF EVIDENCE

IV-retrospective study.

Assessment of health implications related to processing and use of natural wool insulation products

This paper discusses possible health implications related to dust particles released during the manufacture of sheep's wool-based non-woven insulation material. Such insulation may replace traditional synthetic insulation products used in roofs, wall cavities, etc. A review of the literature concerning organic dusts in general and sheep's wool fiber summarizes dust exposure patterns, toxicological pathways and the hazards imposed by inhalation and explosion risk. This paper highlights a need for more research in order to refrain from overgeneralizing potential pulmonary and carcinogenic risks across the industries. Variables existing between industries such as the use of different wool types, processes, and additives are shown to have varying health effects. Within the final section of the paper, the health issues raised are compared with those that have been extensively documented for the rock and glass wool industries.

Time to surgical review: an assessment of the traditional model of emergency surgical care

BACKGROUND

The traditional model for emergency surgical care consists of an on-call team providing service to the emergency department, while simultaneously balancing the demands of elective work. Various newer models, such as the "surgeon of the week" aim to reduce the conflict between elective and emergency duties. Despite the recent focus on newer models, there remains no data on the effectiveness of the traditional model. We aim to assess the efficacy of the traditional model in a large regional hospital.

METHODS

A retrospective study between July 2009 and March 2010 was performed. Primarily, we assessed the initial time to surgical consultation after emergency department referral. Secondarily, we evaluated the impact of time periods, days of week, and case-mix etiology on this consultation time.

RESULTS

The overall median time to surgical consultation after emergency department referral was 30 min (N = 860, P = 0.709). However, the median time to consultation was 60, 30, and 20 min for daytime, evening and night time, respectively (*P < 0.001). Trauma cases had a median time of 15 min, vascular had 45 min, neoplasm had 120 min, while other categories (upper and lower gastroenterology, and skin related) were 30 min (*P = 0.025).

DISCUSSION

Newer models of acute surgical care have desirable outcomes in consultation times. However, regional and economical implications have a substantial impact on which model is feasible at local levels. We demonstrated that the traditional model still remains effective in a large sized tertiary referral unit.

Randomized clinical trial of the benefit of laparoscopy with closure of loop ileostomy

Background

The aim was to compare reversal and laparoscopy with standard reversal of loop ileostomy in terms of hospital stay and morbidity in a randomized study.

Methods

Patients having reversal of a loop ileostomy were randomized to either standard reversal of ileostomy or reversal and laparoscopy. Strict discharge criteria were applied: toleration of two meals without nausea and vomiting, passing a bowel motion, and attaining adequate pain control with oral analgesia. Morbidity and cost were also compared between the two groups.

Results

A total of 74 patients (reversal and laparoscopy 40, standard reversal 34) with a median age of 61 years underwent loop ileostomy reversal; there were 45 men (61 per cent). Ileostomy was most commonly carried out after laparoscopic low anterior resection (36 patients). Median length of stay, based on discharge criteria, was significantly shorter in the reversal and laparoscopy group than in the standard group: 4 (interquartile range 3–4) versus 5 (4–6) days (P = 0·003). The overall morbidity rate was also lower in patients who had ileostomy reversal and laparoscopy: 10 versus 32 per cent (P = 0·023). The median cost per patient was lower in the reversal and laparoscopy group: €3450 (interquartile range 2766–3450) versus €4527 (3843–7263) (P = 0·015). There was no statistically significant difference in American Society of Anesthesiologists fitness grade or time to reversal between the two groups.

Conclusion

Reversal of loop ileostomy with laparoscopy was associated with a shorter hospital stay, lower morbidity and reduced cost compared with the standard technique. Registration number: ISRCTN46101203 (http://www.controlled-trials.com).

Type III hypersensitivity to insulin leading to leukocytoclastic vasculitis

Here, we report the occurrence of leukocytoclastic vasculitis as an outcome of type III allergy to insulin in a patient with type II diabetes mellitus. The diagnosis was made on the basis of anatomo-pathological examination of a skin biopsy.

Central obesity among adults in Egypt: prevalence and associated morbidity

Through a home-based survey, all people aged 18 years and over (n = 1800) in the catchment areas of 12 primary health care centres in 4 Egyptian governorates were subjected to standardized waist and hip measurements. Central obesity was determined based on the waist circumference (WC) and waist-to-hip ratio (WHR) indicators. The age-adjusted prevalence of central obesity among adults was 24.1% and 28.7% based on the WC and WHR indicators respectively. After adjustment for sex and other confounding factors, WC was significantly associated with the risk of diabetes and hypertension, while WHR was not significantly associated with either diabetes or hypertension. No significant association was seen between body mass index and diabetes or hypertension.

Morbidity and mortality of low-birth-weight infants in Egypt

Low birth weight is one of the major determinants of neonatal survival and postneonatal morbidity. This study assessed the morbidity and mortality of low-birth-weight (LBW) infants during the first 3 months. Data were collected for 6701 live births. All singleton liveborn LBW infants as well as a comparison group of normal-birth-weight (NBW) infants were followed up for 3 months. Data were collected on weight, morbidity and mortality using a structured questionnaire. Admission to neonatal intensive care unit and mortality were more frequent in LBW (31.6%, 2.0%) than NBW infants (2.0%, 0.2%). They also had increased risk of neonatal jaundice at 1 month, an increased risk of growth retardation and a much higher risk of mortality.

Anaemia among schoolchildren in Qena Governorate, Upper Egypt

A study was carried out during January/February 2001 in Deshna and Armant Districts of Qena Governorate, Upper Egypt, to establish the prevalence of anaemia among schoolchildren aged 6 to 11 years and define appropriate control interventions in the area. Haemoglobin levels were measured directly in schools using a portable spectrophotometer. The mean (SD) level of haemoglobin in 1844 schoolchildren in 37 schools was 12.79 (1.15) g/dL. Only 12% of children were below the WHO cut-off for anaemia for this age group (< 11.5 g/dL) and no cases of severe anaemia (< 7.0 g/dL) were detected. The low prevalence of mild to moderate anaemia indicates that mass iron supplementation is not justifiable, but routine monitoring of haemoglobin levels should be part of the public health activities in the schools.

Anaemia among schoolchildren in Qena Governorate, Upper Egypt

A study was carried out during January/February 2001 in Deshna and Armant Districts of Qena Governorate, Upper Egypt, to establish the prevalence of anaemia among schoolchildren aged 6 to 11 years and define appropriate control interventions in the area. Haemoglobin levels were measured directly in schools using a portable spectrophotometer. The mean [SD] level of haemoglobin in 1844 schoolchildren in 37 schools was 12.79 [1.15] g/dL. Only 12% of children were below the WHO cut-off for anaemia for this age group [< 11.5 g/dL] and no cases of severe anaemia [< 7.0 g/dL] were detected. The low prevalence of mild to moderate anaemia indicates that mass iron supplementation is not justifiable, but routine monitoring of haemoglobin levels should be part of the public health activities in the schools

Adjuvant active specific immunotherapy for stage II and III colon cancer with an autologous tumor cell vaccine: Eastern Cooperative Oncology Group Study E5283

PURPOSE

A randomized phase III clinical trial of adjuvant active specific immunotherapy (ASI) with an autologous tumor cell-bacillus Calmette-Guérin (BCG) vaccine was conducted to determine whether surgical resection plus ASI was more beneficial than resection alone in stage II and III colon cancer patients.

PATIENTS AND METHODS

Patients (n = 412) with colon cancer (297 with stage II disease, 115 with stage III disease) were randomly allocated to an observation arm or to a treatment arm in which they received three weekly intradermal vaccine injections of 10(7) irradiated autologous tumor cells beginning approximately 4 weeks after surgery. The first two weekly injections also contained 10(7) BCG organisms. Patients were observed for determination of time to recurrence and disease-free and overall survival.

RESULTS

This was a negative study in that after a 7.6-year median follow-up period, there were no statistically significant differences in clinical outcomes between the treatment arms. However, there were disease-free survival (P =.078) and overall survival (P =.12) trends in favor of ASI when treatment compliance was evaluated, ie, patients who received the intended treatment had a delayed cutaneous hypersensitivity (DCH) response to the third vaccination (induration >/=5 mm). Also, the magnitude of the DCH response correlated with improved prognosis. The 5-year survival proportion was 84.6% for those with indurations greater than 10 mm, compared with 45.0% for those with indurations less than 5 mm.

CONCLUSIONS

When all randomized patients were evaluated, no significant clinical benefit was seen with ASI in surgically resected colon cancer patients with stage II or III colon cancer. However, there was an indication that treatment compliance with effective immunization results in disease-free and overall survival benefits.

Prostate-specific antigen (PSA), PSA density and age-adjusted PSA reference values in screening for prostate cancer--a study of a randomly selected population of 2,400 men

Prostate cancer screening with DRE, TRUS, and PSA testing was offered to 2,400 randomly selected men 55-70 years old. Among 1,782 examined, 65 (3.6%) men with prostate cancer were diagnosed. The PSA results were correlated to the diagnosis, the men's age, and the prostate volume. Least square regression analysis was used to calculate the 95% upper confidence intervals for PSA in each year of age in men without prostate cancer. The PPV was calculated for: (i) PSA > 4 ng/ml, (ii) PSAD > 0.15, (iii) PSAD > 0.20 and (iv) age-adjusted PSA reference values. A significant correlation was found between PSA and prostate volume, between PSA and age, and between the prostate volume and age. The calculated annual growth of the prostate was 1.6% and the annual increase in PSA was 2.4%. The age-adjusted upper PSA reference values for the three age categories studied (55-59, 60-64 and 65-70 years) were 5.2, 5.8, and 6.7 ng/ml, respectively. The PPVs for PSA > 4 ng/ml, PSAD > 0.15, PSAD > 0.20, and the age-adjusted PSA reference values were 17%, 14%, 22%, and 27%, respectively. Age-adjusted PSA or PSAD may increase the PPV compared to PSA > 4 ng/ml. The detection rate is, however, inadequate. A PSA cut-off at 4 ng/ml could therefore be maintained in men 55-70 years old. The median PSA values and median prostate volumes calculated for men with benign findings may serve as a reference in future studies.

Recurrent congenital left atrial aneurysm in a newborn

Recurrent congenital left atrial aneurysm presenting in a newborn as cardiac tamponade is described. Such a presentation has not been previously reported.

The eradication of poliomyelitis in Egypt: critical factors affecting progress to date

Poliomyelitis eradication activities in Egypt were reviewed to identify the critical factors for the progress seen by 1995 and to highlight problems that could be avoided in other countries in which poliomyelitis is endemic. National immunization and surveillance data demonstrate that the combination of high routine immunization coverage (>85%) with oral polio vaccine combined with two properly conducted rounds of national immunization days (NIDs) resulted in a 75% reduction in reported polio cases between 1992 and 1993. Available data suggest that earlier control strategies, such as single-round NIDs in 1990 and 1991, the administration of inactivated poliovirus vaccine (IPV) at 2 months of age in 1992-1993, and the use of "mop-up" campaigns while wild poliovirus was still widespread, did not contribute substantially to the recent decline in cases. Proper implementation of the World Health Organization's recommended strategies can eliminate wild poliovirus circulation in the large, densely populated tropical countries in which poliomyelitis remains endemic.

Integrated disease control initiatives: polio eradication and neonatal tetanus elimination in Egypt

Accelerated disease control initiatives, such as polio eradication by the year 2000, may substantially benefit public health programs in general. In Egypt, the control of other vaccine-preventable diseases, most noticeably neonatal tetanus (NT), has been facilitated by the polio eradication initiative. Linking NT reporting with the acute flaccid paralysis (AFP) surveillance system, which had been established for polio eradication, markedly improved the capacity to identify NT high-risk areas and target supplementary immunization activities appropriately. While the close integration of surveillance activities was to the benefit of both programs, mass immunization activities were not conducted simultaneously because of differences in the objectives, target populations, and operational aspects of oral polio vaccine and tetanus toxoid campaigns. In addition to substantial progress toward polio eradication in Egypt since 1988, there has been an 80% reduction in annual NT cases, in part due to the integration of appropriate aspects of these two disease control initiatives.

The role of surveillance in a 'high risk' approach to the elimination of neonatal tetanus in Egypt

BACKGROUND

Despite an international resolution to eliminate neonatal tetanus (NT) as a public health problem by the year 1995, 490000 cases occurred worldwide in 1994. An analysis of the NT elimination programme in Egypt was conducted to determine the utility of a 'high risk' approach in controlling this disease.

METHODS

Three of the indicators for identifying districts at high risk of NT were evaluated. NT rates, tetanus toxoid coverage (TT2+), and urban or rural status. The reduction in NT incidence from 1992 to 1994 was compared between those high risk districts (> or = 1 NT case/1000 live births in 1992) which did or did not conduct supplementary immunization (P = 0.035).

RESULTS

In a multivariate analysis, the strongest indicator of the NT risk in a district was the presence of > or = 1 case/1000 live births in the previous year (Rate ratios [RR] = 3.34 in 1993 and 3.07 in 1994, P < 0.001). The TT2+ coverage was not a reliable indicator of NT risk. Urban areas had a significantly lower risk than rural areas (RR = 0.62) in 1993 and 0.49 in 1994, P < 0.001). The decline in NT rates was greatest in the 'high risk' districts that conducted supplementary immunization in both 1993 and 1994.

CONCLUSIONS

Although tetanus toxoid immunization of pregnant women will protect newborns from NT, TT2+ coverage calculated by the administrative method may not reflect a population's risk of NT. Surveillance data, however, can be used to identify areas where the ongoing risk NT is high. Conducting supplementary immunization in areas that are identified as 'high risk' on the basis of previous NT rates can significantly reduce the number of cases in subsequent years.

Evaluation of house-to-house versus fixed-site oral poliovirus vaccine delivery strategies in a mass immunization campaign in Egypt

Among poliomyelitis eradication activities recommended by WHO are national immunization days. Most campaigns have delivered oral poliovirus vaccine (OPV) from fixed sites, reaching 80-90% of target populations. Although house-to-house vaccination provides nearly universal coverage, countries have been reluctant to use this approach because it is considered more costly and logistically difficult. To quantify the cost-effectiveness of both these strategies, we compared the vaccine coverage and vaccination costs per child for house-to-house and fixed-site delivery (38% and 13% higher, respectively), the costs per child vaccinated were similar. This was due primarily to the high coverage levels achieved in house-to-house delivery (100% versus 86%) and the reduced vaccine wastage. Vaccinating children at highest risk of infection was only 25-50% as expensive on a per child basis using house-to-house delivery, since such children were less likely to visit fixed sites. These findings may not be generalizable to other countries where labour costs are higher and the population density lower; however, house-to-house delivery may prove to be the most cost-effective eradication strategy by ensuring universal access to immunization.

Heparin prevents antigen-induced airway hyperresponsiveness: interference with IP3-mediated mast cell degranulation?

We hypothesized that heparin, because of its antiallergic and/or anti-inflammatory properties, modifies airway hyperresponsiveness (AHR). We studied the effects of inhaled heparin on AHR induced by specific antigen or by platelet-activating factor (PAF), a proinflammatory mediator. Specific lung resistance (sRL) was measured in 17 allergic sheep before, immediately after, and serially for up to 2 h after airway challenge with either specific antigen or PAF. Airway responsiveness was expressed as the cumulative provocative dose of carbachol that increased sRL to 4 cmH2O/s [PD4, in breath units (BU; 1 BU = 1 breath of 1% carbachol solution)]. PD4 was determined on a baseline day and on various experimental days 2 h after airway challenge with antigen or PAF, without or after pretreatment with inhaled heparin (1,000 U/kg). Pretreatment with inhaled heparin prevented antigen-induced bronchoconstriction and postantigen AHR. PD4 was 26 +/- 2.6 (SE), 12 +/- 1.7, and 22 +/- 2.8 BU on baseline, antigen control, and postheparin days, respectively. Heparin given immediately after the antigen challenge failed to modify the magnitude and/or duration of antigen-induced bronchoconstrictor response or postantigen AHR. Heparin also failed to prevent PAF-induced changes in sRL and AHR. In vitro heparin inhibited anti-immunoglobin E- and 1,4,5-inositol triphosphate-mediated degranulation of rat peritoneal mast cells without attenuating the effects of the Ca2+ ionophore A-23187. These data suggest that in "acute responders" heparin prevents antigen-induced bronchoconstriction and AHR, possibly by inhibiting 1,4,5-inositol triphosphate-dependent mast cell mediator release and not by its anti-inflammatory action.

Mechanisms of metabisulfite-induced bronchoconstriction: evidence for bradykinin B2-receptor stimulation

Sodium metabisulfite (MBS) is a food preservative that can trigger bronchoconstriction in asthmatic subjects. Previous studies designed to identify the mechanisms involved in this response have yielded conflicting results. We noted certain similarities between the pharmacology of MBS-induced airway responses and those elicited by bradykinin (BK), another provocating agent in asthmatic subjects. Therefore we used allergic sheep to determine whether MBS-induced bronchoconstriction 1) had a pharmacology similar to that previously seen with BK in this model, including protection by a BK B2-receptor antagonist, NPC-567, and 2) was associated with increased concentrations of immunoreactive kinins in bronchoalveolar lavage. We measured specific lung resistance before and immediately after inhaled buffer and increasing concentrations of MBS (30 breaths of 25, 50, and 100 mg/ml) and calculated the concentration producing 100% increase in specific lung resistance over baseline (PC100). In seven sheep, geometric mean control PC100 was 33.1 mg/ml. Pretreatment with either the anticholinergic agent ipratropium bromide (180 micrograms; PC100 87.1 mg/ml) or the antiasthma drug nedocromil sodium (1 mg/kg aerosol; PC100 97.7 mg/ml) blocked the MBS-induced bronchoconstriction (P less than 0.05), whereas the histamine H1-receptor antagonist chlorpheniramine (2 mg/kg iv) was ineffective. Furthermore the MBS-induced bronchoconstriction was not affected by the neutral endopeptidase inhibitor thiorphan (40 breaths of a 1 mg/ml solution) or the angiotensin-converting enzyme inhibitor enalaprilat (2.5 mg aerosol). In six sheep the MBS-induced bronchoconstriction was completely blocked by NPC-567 (20 breaths, 5 mg/ml aerosol): after treatment with NPC-567 mean PC100 was 100 mg/ml compared with 57.5 mg/ml in the control trial (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Attenuation of platelet-activating factor-induced airway responses with methylprednisolone succinate in sheep

Intratracheal instillation of platelet-activating factor (PAF) in sheep produces bronchoconstriction and airway hyperresponsiveness (AHR) by a two-stage process that involves the initial stimulation of PAF receptors followed by the secondary generation of proinflammatory mediators. Because the biological effects of PAF may be mediated by these proinflammatory metabolites, it is possible that a steroidal anti-inflammatory agent would modify the airway responses of PAF. We measured specific lung resistance (sRL) in sheep (n = 11) before, immediately after, and serially for up to 2 h after intratracheal instillation of PAF (30 micrograms/kg). Airway responsiveness was measured 2 h post-PAF when sRL had returned to baseline and was expressed as the cumulative provocating dose of carbachol that increased sRL to 4 l.cmH2O.l-1.s (PD4). PD4 was determined on a control day and on different experiment days without or after treatment with intravenous methylprednisolone (MPS; 1 mg/kg) administered 3 h before (n = 6), 20 min before PAF (n = 7), or 20 min after PAF challenge (n = 7). PAF increased sRL by 222 +/- 44% (SE) above baseline and decreased PD4 of carbachol by 44 +/- 5% (P less than 0.05). Pretreatment (both 3 h and 20 min) with MPS attenuated the PAF-induced increases in sRL, whereas its administration 20 min post-PAF had no effect. Irrespective of the effects on sRL, MPS administration inhibited the PAF-induced AHR.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipid mediators contribute to oxygen-radical-induced airway responses in sheep

The purpose of this study was to determine if the bronchoconstriction and airway hyperresponsiveness (AHR) resulting from aerosolized xanthine (x; 0.1%)-xanthine oxidase (xo; 4.1 U) and the subsequent production of oxygen radicals is mediated by the secondary generation of lipid mediators. In seven conscious sheep, specific lung resistance (SRL) was measured before and after x-xo challenge; approximately 30 min later when SRL had returned to baseline, airway responsiveness to carbachol was determined from dose-response curves by calculating the cumulative provocating dose of carbachol in breath units (BU, defined as one breath of a 1% wt/vol carbachol solution) that increased SRL 400% over baseline (PD400). Inhaled x-xo caused in immediate increase in SRL of 162 +/- 36% (mean +/- SE; p less than 0.05) over baseline and decreased PD400 from a baseline value of 32.5 +/- 5.0 to 16.6 +/- 1.7 BU (p less than 0.05). Pretreatment with the H2O2 scavenger, catalase (CAT,; 38 mg aerosol), methylprednisolone succinate (MS; 1 mg/kg given intravenously), the cyclooxygenase inhibitor, indomethacin (IND; 2 mg/kg given intravenously), and the PAF antagonist, WEB-2086 (3 mg/kg given intravenously) all attenuated the x-xo-induced increase in SRL (p less than 0.05); the leukotriene D4 antagonist, MK-571 (5 mg by aerosol) had no effect. All agents inhibited the x-xo-induced decrease in PD400: mean BUs were 27 after CAT, 32 after WEB-2086, 34 after IND, 31 after MS, and 25 after MK-571 (all p less than 0.05 versus x-xo alone).(ABSTRACT TRUNCATED AT 250 WORDS)

PAF-induced airway responses in sheep: effects of a PAF antagonist and nedocromil sodium

Platelet-activating factor (PAF) is a potent inflammatory mediator that can cause bronchoconstriction and airway hyperresponsiveness in selected human subjects and animals. The mechanism by which PAF induces these changes is not clearly understood. We therefore studied the effects of intratracheal instillation of PAF (30 micrograms/kg) on airway resistance and airway responsiveness in allergic sheep (n = 7) and attempted to modulate these effects with the specific PAF antagonist, WEB-2086, and the antiasthmatic agent, nedocromil sodium (NED). Specific lung resistance (SRL) was measured to assess bronchial responses to PAF, and airway responsiveness was determined by deriving a provocative dose of carbachol in breath units causing an increase in SRL to 4 L times centimeters of H2O per liters per second (PD4) from carbachol dose-response curves. PAF instillation increased mean +/- SD SRL to 228 +/- 134% above baseline. Two to 4 hours after PAF instillation, PD4 decreased by 55 +/- 9% from a baseline of 39 +/- 9 breath units (p less than 0.05). Airway responsiveness remained increased at 24 hours but returned to baseline by 48 hours. Pretreatment with WEB-2086 (3 mg/kg, intravenously) or NED (1 mg/kg, nebulized) blocked (p less than 0.05) PAF-induced bronchoconstriction and PAF-induced airway hyperresponsiveness. Instillation of lyso-PAF (30 micrograms/kg) did not cause bronchoconstriction or airway hyperresponsiveness. Thus, instilled PAF causes bronchoconstriction and airway hyperresponsiveness in allergic sheep by a receptor-mediated mechanism that likely involves the release of secondary mediators, the latter process being sensitive to NED.

The effects of short-term venous congestion on forearm venous volume and reactive hyperemia blood flow in human subjects

Congestive heart failure is associated with a reduction in limb venous volume at an effective venous pressure of 30 mm Hg (VV[30]). Further, an attenuated arteriolar dilation in response to a metabolic stimulus has been demonstrated. It was the purpose of this study to determine to what extent the chronic elevation in venous pressure seen in heart failure might explain these abnormalities of the limb circulation. Ten normal human volunteers were subjected to venous congestion of one arm for three hours at 70 mm Hg. A mercury-in-rubber strain gauge plethysmograph was used to measure forearm VV [30] and forearm blood flow at rest after release of five minutes of arterial occlusion (the reactive hyperemia response). Congestion reduced VV [30] 22%, resting forearm blood flow 49% and peak reactive hyperemia blood flow 25%. Thus, chronic venous congestion per se may significantly reduce limb venous volume as well as resting and reactive hyperemia blood flow.