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Biomedical subjects

R T Bryan

Publications and source records attributed to R T Bryan.

At least 19 recordsLinked to original sources

Axillary lipoblastoma--tumor recurrence in the right atrium.

This case report describes, for the first time, vascular invasion and recurrence of a lipoblastoma 6 months after the macroscopically complete excision of the initial cervico-axillary tumour. The importance of cytogenetics in the diagnosis of lipoblastoma is emphasized, as is the need to be wary of the diagnosis of lipoma in infancy.

Axilla↗

The role of beta-catenin signaling in the malignant potential of cystitis glandularis.

PURPOSE: Chronic inflammation is a risk factor for malignant transformation in the bladder. The pro-inflammatory cytokine tumor necrosis factor-alpha (TNFalpha) is a mediator of such inflammation that induces nuclear localization of the adherens junction component beta-catenin. This mechanism has a key role in the initiation and progression of the premalignant lesion Barrett's metaplasia of the esophagus. Cystitis glandularis is a metaplastic lesion of the bladder urothelium occurring in the presence of chronic inflammation and in up to 13% of asymptomatic bladders. Two subtypes are described (typical and intestinal/colonic) with uncertain malignant potential. Etiologically and histologically cystitis glandularis mimics Barrett's metaplasia. We investigated the roles of beta-catenin and TNFalpha in cystitis glandularis. MATERIALS AND METHODS: Immunohistochemistry and immunofluorescence were used to demonstrate the expression and localization of E-cadherin, beta-catenin and TNFalpha in 9 sections of typical cystitis glandularis and 4 of intestinal/colonic cystitis glandularis. Appropriate controls were used for all experiments. RESULTS: Immunohistochemistry demonstrated normal membranous expression of E-cadherin and beta-catenin in all cystitis glandularis sections with increased TNFalpha expression. Immunofluorescence showed nuclear localization of beta-catenin in the intestinal/colonic subtype only, which was not observed in typical cystitis glandularis. CONCLUSIONS: The presence of nuclear beta-catenin suggests that intestinal/colonic cystitis glandularis shares the same signaling pathway with the premalignant lesion Barrett's metaplasia of the esophagus and the intestinal/colonic subtype of cystitis glandularis may have the potential to progress to malignancy. This finding has important implications for the management of this lesion.

Adenocarcinoma↗

Delay and survival in bladder cancer.

OBJECTIVE: To assess in detail and evaluate the effect on survival of delays in the diagnosis and treatment of cancer (which might lead to a worse prognosis), dividing the delay from onset of symptoms to first treatment into several components, comprising patient delay, general practitioner (GP) delay, and two or more periods of hospital delay. PATIENTS AND METHODS: Data were prospectively collected on 1537 new cases of urothelial cancer in the West Midlands from 1 January 1991 to 30 June 1992. Death information was obtained from the West Midlands Cancer Intelligence Unit and censored at 31 July 2000. The influence of delay times on survival was explored. RESULTS: The median delay from onset of symptoms to GP referral was 14 days (Delay 1), from GP referral to first hospital attendance was 28 days (Delay 2), and from first hospital attendance to first transurethral resection of bladder tumour was 20 days (Delay 3). The median hospital delay (Delay 2 + 3) was 68 days and the median total delay (Delay 1 + 2 + 3) was 110 days. Patients with a shorter Delay 1 had a lower tumour stage and a 5% better 5-year survival. Patients with a shorter hospital delay had worse survival; total delay had no effect on survival. CONCLUSIONS: There was significantly better survival for patients referred to hospital within 14 days of the onset of symptoms. The relationship between delay and survival in bladder cancer is complex. Hospital delays may be influenced more by comorbidity than by the characteristics of the tumour. However, the adverse effects of delay seem to be most pronounced for patients with pT1 tumours.

Aged↗

Laparoscopic peritoneal lavage in staging gastric and oesophageal cancer.

AIMS: Accurate staging of gastric, oesophageal and oesophagogastric cancer is essential to avoid unnecessary laparotomies in patients where only palliation is appropriate. This requires a multimodal approach utilizing endoscopy, computed tomography and laparoscopy. Previous authors have found that the presence of free peritoneal tumour cells (FPTCs) detected at laparoscopy or laparotomy confers a poorer prognosis. However, various methods of peritoneal lavage are described. The aim of this study was to evaluate the prognostic value of our technique of peritoneal lavage. MATERIALS AND METHODS: 88 staging laparoscopies with peritoneal lavage were carried out between March 1997 and February 1999 on patients eligible for attempted curative resection of a gastric, oesophageal or oesophagogastric cancer. During laparoscopy the pelvis was irrigated with 200 ml of normal saline, with 100 ml aspirated and examined cytologically. Patients were followed-up until September, 1999. RESULTS: 11 patients had FPTC-positive cytology with a median survival following laparoscopy of 122 days (95% CI 82-161) with only a single patient surviving more than one year. In the FPTC-negative group, median survival was 378 days (95% CI 256,-). Log-rank Chi(2)=16.7, P<0.001. CONCLUSIONS: The presence of FPTCs detected by our technique is a contraindication to attempted curative resection - palliation only (medical or surgical) is appropriate.

Adult↗

Infectious disease morbidity in the US region bordering Mexico, 1990-1998.

The United States and Mexico share an international boundary approximately 3000 km long. This border separates 2 nations with great differences in health status. The objective of this study was to assess morbidity due to infectious diseases in the US region bordering Mexico. The incidence between 1990 and 1998 of 22 nationally notifiable infectious diseases was compared between border and nonborder regions. Disease rates, reflected as rate ratios, were higher in the border region for botulism, brucellosis, diphtheria, hepatitis A, measles, mumps, rabies, rubella, salmonellosis, and shigellosis than in either of 2 nonborder comparison regions. These data indicate that incidence rates for a variety of infectious diseases of public health importance are significantly higher in the United States along the Mexican border than in nonborder regions. These results suggest that an inadequate public health infrastructure may contribute to excess morbidity due to infectious diseases in the border region.

Adolescent↗

Declining CD4+ T-lymphocyte counts are associated with increased risk of enteric parasitosis and chronic diarrhea: results of a 3-year longitudinal study.

From January 1991 through September 1994, we observed people who were infected with HIV to assess the impact of enteric parasite-associated diarrhea. Respondents answered comprehensive questionnaires covering clinical and epidemiologic information and provided stool specimens monthly, which were examined unstained as well as stained with trichrome, chromotrope 2R, and with Kinyoun carbol-fuchsin, and with indirect immunofluorescence for Cryptosporidium. In all, 602 participants, who were interviewed, provided stool specimens at 3254 monthly visits. Parasites were associated with 50 of 354 (14.1%) acute diarrheal episodes (lasting < or = 28 days) and with 97 of 279 (34.8%) chronic episodes (lasting > 28 days). A parasite was associated with 31 of 222 (14.0%) episodes that occurred when CD4+ counts were > or = 200 cells/microl and with 150 of 566 (26.5%) episodes that occurred when CD4+ counts were < 200 cells/microl. The most commonly identified parasite was C. parvum, which was associated with 18 of 354 (5.1%) acute episodes and 36 (12.9%) of the 279 chronic episodes of diarrhea. In this patient population, enteric protozoan parasites were commonly associated with illness, particularly as immunosuppression worsened, and were more likely to be associated with chronic rather than acute diarrhea.

AIDS-Related Opportunistic Infections↗

Hantavirus pulmonary syndrome in pregnancy.

This comprehensive case review of hantavirus pulmonary syndrome (HPS) during pregnancy in 5 women characterizes the effect of Sin Nombre virus infection on maternal and fetal outcomes. Histopathologic, serological, and clinical information were evaluated for evidence of vertical transmission. Maternal ages ranged from 20 to 34 years and gestational ages from 13 to 29 weeks. Symptoms, physical findings, and laboratory values other than those related to pregnancy were not noticeably different from those of nonpregnant patients with HPS, although fevers were somewhat lower. One maternal death and 2 fetal losses occurred. Gross, microscopic, and immunohistochemical examination for hantavirus antigen were done on 2 fetal autopsies and 3 placentas showing no evidence of transplacental hantavirus transmission. There was no serological evidence of conversion in the 3 surviving children. Maternal and fetal outcomes of HPS appear similar to those of nonpregnant HPS patients and of pregnant patients with other causes of acute respiratory distress syndrome. No evidence of vertical transmission of Sin Nombre virus was found.

Adult↗

Primary sternal osteomyelitis in infants: a report of two cases.

Primary sternal osteomyelitis in infants, older children, and adults is rare. Secondary sternal osteomyelitis, however, is more common because of the increased frequency of cardiothoracic surgery and intravenous drug abuse. Primary sternal osteomyelitis is reviewed, two infants with further cases of primary sternal osteomyelitis are presented, and diagnosis and management are discussed.

Adult↗

Viral hemorrhagic fevers and hantavirus infections in the Americas.

Several arenaviruses and hantaviruses have been isolated in the Americas during the last 4 decades. These are rodent-borne viruses responsible for the South American hemorrhagic fevers (SAHF) and hantavirus pulmonary syndrome (HPS). Although rare, SAHF and HPS are serious illnesses with high mortality rates. Most viral isolates found in the Americas represent New World lineages of their respective viral families. Their presence in the Western hemisphere is likely ancient, their relationship with their rodent hosts is likely coevolutionary, and their recent detection forebodes the likelihood of detecting additional arena- and hantaviral species in the Americas.

Americas↗

Application of the enzyme-linked immunoelectrotransfer blot to filter paper blood spots to estimate seroprevalence of cysticercosis in Bolivia.

An enzyme-linked immunoelectrotransfer blot (EITB) assay was used to study the prevalence of cysticercosis in rural Bolivia. Dried blood spots on filter paper from fingersticks were used as assay samples. Before the serosurvey, experiments were performed to show that samples eluted from dried whole blood on filter paper exhibited no decrease in sensitivity when compared with the more traditional serum samples used in the EITB. Fingerstick blood dried on filter paper is a convenient, economical way of transporting and storing field samples for epidemiologic surveys of cysticercosis in developing countries. This report shows the utility of this sample collection method in underdeveloped countries where refrigeration is not possible and where venipuncture is a problem. Blood was obtained from randomly selected residents in three rural regions of Bolivia: Chuquisaca (n = 1,859), Cochabamba (n = 1,516), and Tarija (n = 1,010). The estimated seroprevalence on 10% of the sample collected for the three regions were 9%, 4.5%, and 2%, respectively.

Animals↗

Laguna Negra virus associated with HPS in western Paraguay and Bolivia.

A large outbreak of hantavirus pulmonary syndrome (HPS) recently occurred in the Chaco region of Paraguay. Using PCR approaches, partial virus genome sequences were obtained from 5 human sera, and spleens from 5 Calomys laucha rodents from the outbreak area. Genetic analysis revealed a newly discovered hantavirus, Laguna Negra (LN) virus, to be associated with the HPS outbreak and established a direct genetic link between the virus detected in the HPS cases and in the C. laucha rodents, implicating them as the primary rodent reservoir for LN virus in Paraguay. Virus isolates were obtained from two C. laucha, and represent the first successful isolation of a pathogenic South American hantavirus. Analysis of the prototype LN virus entire S and M and partial L segment nucleotide and deduced amino acid sequences showed that this virus is unique among the Sigmodontinae-borne clade of hantaviruses. Analysis of PCR fragments amplified from a serum sample from a Chilean HPS patient, who had recently traveled extensively in Bolivia (where C. laucha are known to occur), revealed an LN virus variant that was approximately 15% different at the nucleotide level and identical at the deduced amino acid level relative to the Paraguayan LN virus. These data suggest that LN virus may cause HPS in several countries in this geographic region.

Animals↗

An outbreak of hantavirus pulmonary syndrome in western Paraguay.

During an investigation of hantavirus pulmonary syndrome (HPS) in Paraguay in 1995, sera from persons with HPS-like illness, houshold contacts of confirmed HPS case-patients, and a sample of the area residents were analyzed by ELISA for antibodies to Sin Nombre virus (SNV). Rodent serosurveys and analysis of precipitation records were also conducted. Twenty-three of 24 available probable cases were SNV antibody-positive, 17 of whom were ill between July 1995 and January 1996. Four (14.8%) of 27 case-contacts and 44 (12.8%) of 345 community residents were also seropositive. Calomys laucha (vesper mouse) was the most common rodent species captured and the most frequently SNV-seropositive. Rainfall in May 1995 was 10-fold greater than that seen in May over the preceding 11 years. This 17 case-cluster represents the largest documented outbreak since HPS was first recognized in 1993. Calomys laucha is the likely primary rodent reservoir for a SNV-like hantavirus in western Paraguay. Fluctuations in monthly precipitation rates may have contributed to increased risk for HPS in this region.

Adult↗

Epidemiologic linkage of rodent and human hantavirus genomic sequences in case investigations of hantavirus pulmonary syndrome.

Sin Nombre virus (SNV) causes the zoonotic disease hantavirus pulmonary syndrome (HPS). Its mechanisms of transmission from rodent to human are poorly understood. It is possible that specific genetic signature sequences could be used to determine the probable site of each case-patient's exposure. Environmental assessments suggested 12 possible sites of rodent exposure for 6 HPS patients. Rodents were captured at 11 of the 12 sites and screened for SNV infection within 2 weeks of the patient's diagnosis. Viral sequences amplified from tissues of rodents at each site were compared with those from case-patients' tissues. Rodents bearing viruses with genetic sequence identity to case-patients' viruses across 2 genomic segments were identified in 4 investigations but never at >1 site. Indoor exposures to rodents were especially common at implicated sites. By distinguishing among multiple possible sites of exposure, viral genotyping studies can enhance understanding of the conditions associated with infection by SNV.

Animals↗

Hantavirus pulmonary syndrome: the first 100 US cases.

In the spring of 1993, hantavirus pulmonary syndrome (HPS) "emerged" in the southwestern United States, where a multiagency investigation led to the rapid description of this new clinical entity and its etiology. Analysis of the first 100 US cases identified showed that the disease was distributed in 21 states, had gone unrecognized since at least 1959, and had a distinct spring-early summer seasonality. Of the infected persons, 54% were male; 63% were Caucasian, 35% were Native American, and 2% were African American. The average age of case-patients was 34.9 years, and 8 were children or adolescents aged < or = 16 years. The overall case-fatality rate was 52%. There was a 91% concordance among serologic, immunohistochemical, and molecular results. HPS in the United States is caused by at least three newly described pathogenic hantaviruses, each of which has a distinct rodent host, and cases of HPS have been recently recognized in Canada and South America. National surveillance of this sporadic disease remains essential for further defining the epidemiology and clinical spectrum.

Adolescent↗