THE INTRARENAL PRESSURE DURING EXPERIMENTAL RENAL HYPERTENSION

The intrarenal interstitial pressure was measured during the course of experimental renal hypertension in dogs. In perinephritic hypertension, produced by wrapping the kidney in a cellophane bag, the intrarenal pressure rose slowly from the normal value of 25 mm. Hg to a final level of about 60 mm. Hg. Strong pressure pulsations were observed in the renal parenchyma during this type of hypertension. In the hypertension following partial occlusion of the renal artery, the intrarenal pressure remained approximately normal, except in malignant hypertension when it tended to decline to about 9 mm. Hg. The hypertension of perinephritis is interpreted as a consequence of renal ischemia, the high intrarenal pressure, produced by the constricting fibrotic hull, acting to reduce the effective perfusion pressure of the kidney. The two experimental hypertensions herein examined are considered as examples of influent resistance hypertensions and effluent resistance hypertensions, the former being due to renal arterial or arteriolar resistance and the latter due to renal venous resistance, specifically at the arcuate-interlobar junction. The application of this concept to renal hypertensive disease in man is discussed.     

Interpreting declines in HIV test positivity: an analysis of routine data from Zimbabwe's national sex work programme, 2009–2019

IntroductionEarly diagnosis of HIV is critical for epidemic control. To achieve this, successful testing programmes are essential and test positivity is often used as a marker of their performance. The aim of this study was to analyse trends and predictors of HIV test positivity over time and explore how an understanding of seroconversion rates could build on our interpretation of this indicator among female sex workers in Zimbabwe.MethodsWe analysed HIV test data from Zimbabwe''s nationally scaled sex work programme between 2009 and 2019. We defined test positivity as the proportion of all tests that were HIV positive and measured new diagnoses by estimating seroconversion rates among women with repeat tests, defined as an HIV‐positive test after at least one HIV‐negative test in the programme. We used logistic regression to analyse test positivity over three time‐periods: 2009–2013, 2014–2017 and 2018–2019, adjusting for potential confounding by demographic factors and the mediating effects of time since last HIV test. We calculated the seroconversion rates for the same time‐periods.ResultsDuring the 10‐year study period, 54,503 tests were recorded in 39,462 women. Between 2009 and 2013, 18% of tests were among women who reported testing in the previous 6 months. By 2018–2019, this had increased to 57%. Between 2018 and 2019, test positivity was 9.6%, compared to 47.9% for 2009–2013 (aOR 6.08 95% CI 5.52–6.70) and 18.8% for 2014–2017 (aOR 2.17 95% CI 2.06–2.28). Adjusting for time since last test reduced effect estimates for 2009–2013 (aOR 4.03 95% CI 3.64–4.45) and 2014–2017 (aOR 1.97 95% CI 1.86–2.09) compared to 2018–2019. Among 7573 women with an initial HIV‐negative test in the programme and at least one subsequent test, 464 tested HIV positive at a rate of 3.9 per 100 pyar (95% CI 3.5–4.2).ConclusionsTest positivity decreased among women testing through the programme over time, while seroconversion rates remained high. These declines were partly driven by changes in individual testing history, reflecting comprehensive coverage of testing services and greater knowledge of HIV status, but not necessarily declining rates of seroconversion. Understanding testing history and monitoring new HIV infections from repeat tests could strengthen the interpretation of test positivity and provide a better understanding of programme performance.     

Nurses Share Real‐Life Research Experiences

Nursing for Women's Health convened a group of nurse researchers for a roundtable discussion about the relationship of research to the profession of nursing, how research drives evidence‐based practice and how nurses can get involved in research and in its application to the care of women and newborns.     

Repeated mild brain injuries result in cognitive impairment in B6C3F1 mice

Experimental investigations of single mild brain injury (SMI) show relatively little resultant cognitive impairment. However, repeated mild brain injuries (RMI), as those sustained by athletes (e.g., football, hockey, and soccer players) may have cumulative effects on cognitive performance and neuropathology. Numerous clinical studies show persistent, latent, and long-term consequences of RMI, unlike the episodic nature of SMI. The nature of repeated traumatic brain injury (TBI) introduces confounding factors in invasive and even semiinvasive animal models of brain injury (e.g., scar formation). Thus, the present study characterizes SMI and RMI in a noninvasive mouse weight drop model and the cumulative effects of RMI on cognitive performance. Investigation of drop masses and drop distances revealed masses of 50, 100, and 150 g dropped from 40 cm resulted in 0% mortality, no skull fracture, and no difference in acute neurological assessment following sham injury, SMI, or RMI. Cumulative effects of RMI were examined following four mild brain injuries 24 h apart induced by 50-, 100-, or 150-g masses dropped from 40 cm through histological measures, mean arterial pressure, and measures of complex/spatial learning. RMI produced no overt cell death within the cortex or hippocampus, no evidence of blood-brain barrier compromise, and no significant change in mean arterial pressure. Following testing in the Morris water maze (MWM) on days 7-11 after initial injury, mice in the RMI 100-g and RMI 150-g groups had significantly longer MWM goal latencies compared to sham, SMI 150-g, and RMI 50-groups. Additionally, the evident cognitive deficit manifested in the absence of observed cell death. This is the first study to show complex/spatial learning deficits following RMI, similar to the visual/spatial perception and planning deficits observed in clinical studies.     

The pathogenesis of pseudoachalasia: a clinicopathologic study of 13 cases of a rare entity

Pseudoachalasia is an esophageal motor disorder usually associated with malignancy that has clinical, radiographic, and manometric findings that are often indistinguishable from primary achalasia. There are few reports examining the histologic features of the associated neoplasms and their relationship with the esophageal myenteric plexus. We studied the clinical and pathologic features of 13 cases of pseudoachalasia seen at our institution between 1979 and 1999. Detailed clinical and radiographic data were obtained from medical records. In all cases available histologic material was reviewed to confirm the presence and type of associated neoplasm. When possible, the relationship of the neoplasm to the esophageal myenteric plexus was examined. In selected cases immunohistochemical stains were performed to further evaluate this relationship. All patients had clinical, radiographic, and manometric features similar to primary achalasia. The cohort included seven men and six women, age range 24-79 years (median 61 years). Associated neoplasms included esophageal adenocarcinoma arising in Barrett's esophagus (n = 1), adenocarcinoma of the esophagogastric junction (n = 7), metastatic renal cell carcinoma to the esophagogastric junction (n = 1), breast adenocarcinoma (n = 1), pulmonary small cell carcinoma (n = 1), pleural malignant mesothelioma (n = 1), and mediastinal fibrosis (n = 1). The mechanism of pseudoachalasia was consistent with neoplastic infiltration of the esophageal myenteric plexus in 11 cases. Neoplastic cells surrounded myenteric ganglion cells, which appeared normal in number and morphology. In the patient with pulmonary small cell carcinoma, there was no evidence of neoplastic infiltration of the esophagogastric junction, and anti-ANNA-1 antibody was detected, suggesting a paraneoplastic syndrome. Tissue obtained at the time of esophagomyotomy revealed lymphocytic myenteric inflammation and marked depletion of ganglion cells identical to that seen in primary achalasia. The mechanism pseudoachalasia in the patient with breast adenocarcinoma is uncertain, as there was no evidence of direct involvement of the esophagogastric junction. In summary, we describe 13 cases of pseudoachalasia resulting in a clinical syndrome indistinguishable from primary achalasia. The most common mechanism is direct involvement of the esophageal myenteric plexus by neoplastic cells. Rarely, a distant neoplasm may cause this syndrome as a paraneoplastic process.     

Sentinel node biopsy in vulvar and vaginal melanoma: presentation of six cases and a literature review

Background Urogenital melanoma is a rare neoplasm with poor prognosis. Its management in the past involved radical vulvectomy and complete bilateral inguinofemoral lymphadenectomy. Sentinel lymph node biopsy is an accurate low-morbidity procedure when used in the context of cutaneous melanoma. However, prophylactic lymphadenectomy has not been shown to improve survival of melanoma patients. We wanted to determine the feasibility of sentinel lymph node biopsy in patients with female urogenital melanoma as a staging procedure. Methods Six patients with vulvar or vaginal melanomas underwent preoperative lymphatic mapping with^99mTc-labeled sulfur colloid followed by sentinel lymphadenectomy. In addition, we reviewed the literature on the application of sentinel lymph node biopsy in urogenital tract melanomas. Results One or more sentinel nodes were identified in all six patients by lymphoscintigraphy. All patients underwent sentinel lymphadenectomy, except for one patient with a deep vaginal melanoma that drained to pelvic nodes. The five successful cases had unilateral drainage patterns. None of the sentinel lymph nodes excised had tumor invasion. Combined with five other patients from the published literature, the success rate of localizing sentinel lymph nodes in the patients with urogenital melanoma approaches 100%. Conclusions This experience, plus reports of a small number of patients from three similar studies, supports the impression that sentinel lymph node biopsy is feasible for vulvar and vaginal melanoma.     

Mediastinal synovial sarcoma: report of two cases with molecular genetic analysis

Synovial sarcoma occurs predominantly in the paraarticular regions of the extremities. Synovial sarcoma of the mediastinum is an exceedingly rare neoplasm that has overlapping histologic and immunophenotypic features with other tumors in the differential diagnosis. We describe two cases. One is a 67-year-old patient who presented with chest pain and shortness of breath. Diagnostic imaging revealed a mediastinal mass extending over the cardiac apex. Histopathology, immunohistochemistry, and molecular genetic analysis confirmed the diagnosis of synovial sarcoma. The patient underwent surgical resection and postoperative radiation therapy. He is alive and well 18 months after diagnosis. This case illustrates the importance of proper procurement of frozen tissue for molecular genetic analysis for the identification of the t(X;18), characteristic of synovial sarcoma. Detection of this translocation is of paramount importance to confirm this diagnosis, particularly when this neoplasm arises in atypical locations outside the extremities.     

Peripheral Arterial Occlusive Disease: Magnetic Resonance Imaging and the Role of Aggressive Medical Management

Atherosclerosis accounts for most peripheral arterial occlusive disease (PAD). Although many of the risk factors for atherosclerotic coronary artery disease (CAD) such as hyperlipidemia have been identified as risk factors for peripheral arterial disease, strong evidence is lacking that risk factor modification is effective in halting progression or improving outcomes. A better understanding is needed regarding the clinical and pathophysiologic responses to risk factor modification. This review describes current advances in the medical management for PAD including lipid modification antiplatelet therapy, angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, exercise, and endovascular intervention. In addition, we discuss our active ELIMIT Trial (Effect of Lipid Modification on Peripheral Arterial Disease after Endovascular Intervention). We test the hypothesis that an aggressive regimen of serum lipid modification will inhibit the progression of atherosclerosis in femoral arteries and reduce the incidence of restenosis of femoral arteries following endovascular stenting by decreasing thrombosis and inflammation. This study will provide a novel strategy for retarding or preventing progression of atherosclerosis and re-stenosis of peripheral arterial disease following arterial revascularization procedures. Importantly, our magnetic resonance imaging studies will provide quantitative data on the vascular lesions in PAD. These studies will advance our understanding of the molecular mechanisms of inflammation and thrombosis associated with aggressive lipid modification. This work was presented at the Molecular Surgeon Symposium on Vascular Injury, Repair and Remodeling at the Baylor College of Medicine, Houston, Texas, May 15 and 16, 2006. The symposium was supported by a grant from the National Institutes of Health National Institute of Health (to C. Chen: R13 HL0836500).     

Are all ICUs the same?

The ability to compare intensive care units (ICUs) and determine whether they provide the same level of care with regard to efficacy, efficiency, and quality is a cornerstone of understanding critical care and improving the quality of that care. Without collecting high-quality data, adjusted for severity of illness and analyzed in a comparative fashion, it would not be possible to describe best practices objectively, to identify which ICUs are doing a good job or to learn from those units that are. This review article discusses how and why ICUs are compared. Particular attention is focused on the severity of illness scores, standardized mortality, and comparative reporting. A data collecting network, Virtual Pediatric Systems, limited liability corporation (VPS, LLC), designed for the purposes of determining where differences in critical care can be identified and the value that this adds in improving quality is discussed. Finally, results from this large data sharing collaborative describing the practice of pediatric critical care are included for the purpose of pediatric intensive care units practice benchmarks.