A Sensitive and Quantitative Assay to Enumerate and Measure Mycobacterium leprae Viability in Clinical and Experimental Specimens

Mycobacterium leprae, the etiologic agent of leprosy, cannot be cultured on artificial media. This characteristic, coupled with its long generation time, presents a number of unique challenges to studying this pathogen. One of the difficulties facing both researchers and clinicians is the absence of a rapid test to measure the viability of M. leprae in clinical or experimental specimens. The lack of such a tool limits the understanding of M. leprae immunopathogenesis and makes determining the efficacy of drug treatments difficult. With this in mind, we developed a robust two-step molecular viability assay (MVA) that first enumerates the M. leprae in the tissue; then, this data is used to normalize bacterial RNA quantities for the second step, in which the expression of M. leprae esxA and hsp18 are measured. This assay is specific and sensitive enough to be used on most clinical samples. This protocol describes the steps required to extract DNA and RNA from M. leprae-infected tissue, enumerate M. leprae, and measure M. leprae viability based on the normalized expression of two M. leprae-specific genes (hsp18 and esxA). This protocol also outlines an optimal laboratory design and workflow for performing this assay. © 2022 The Leprosy Mission Nepal. Current Protocols published by Wiley Periodicals LLC. This article has been contributed to by US Government employees and their work is in the public domain in the USA. Basic Protocol 1: DNA and RNA P purification from M. leprae-infected tissue Basic Protocol 2: Enumeration of M. leprae by RLEP qPCR on the DNA fraction Basic Protocol 3: Calculation of M. leprae per tissue and normalization of RNA Basic Protocol 4: Reverse-transcription of normalized RNA to generate cDNA Basic Protocol 5: Determination of M. leprae viability using HSP18 and ESXA qPCR on the cDNA Support Protocol 1: M. leprae qPCR primer/probe stock preparation Support Protocol 2: Preparation of plasmid stocks and standard curves.

Caeco-peritoneal band as a potential cause of right iliac fossa pain in children

BACKGROUND

A caeco-peritoneal band (CPB) has been observed during diagnostic laparoscopy for chronic right iliac fossa (RIF) pain. This has a veil-like configuration and arises along a broad base from the caecum and ascending colon and attaches to the anterior abdominal wall.

METHODS

Retrospective analysis of a prospectively collected database of 31 patients, aged 11-16, who underwent diagnostic laparoscopy for ongoing RIF pain over a 10-year period was analysed for intra-operative presence of the CPB. The patients' symptoms, past medical history, diagnostic workup, surgical findings and outcome were evaluated.

RESULTS

CPB was identified in five patients. All presented with chronic RIF pain and had inconclusive preoperative investigations. Two patients underwent previous surgery. In all cases, the CPB was the sole abnormal finding on diagnostic laparoscopy. Symptoms resolved following division of the CPB with no recurrence of pain at a mean follow-up of 575 days.

CONCLUSIONS

CPB is a potential cause of chronic RIF pain in patients with unremarkable examination findings and negative serological and radiological investigations. Laparoscopic identification and division of the CPB has produced symptom resolution in this cohort of patients.

Is there an increase in the incidence of uterine carcinosarcoma in north-east Scotland? A 19 years population-based cohort study

Background and aims

The incidence of uterine carcinosarcoma and factors associated with its survival are little known and this study helps to address this question for women residing in north-east Scotland.

Methods and results

Data were collected from women diagnosed with carcinosarcoma of the uterus residing in north-east of Scotland from 1991 to 2009. Kaplan–Meier plots and Cox regression analysis were used for analysis. A total of 43 women were analysed during this period. The median survival was 25 months. The estimated five-year survival for stage I/II disease was 52.5% (95% CI: 30.5–74.5%). The 2-year survival rate for stage III/IV disease was 46% (95% CI: 16–75%). There was an increase in the incidence during this period. Improved survival was seen in early-stage disease (FIGO stages I and II) and in the absence of lymphovascular space invasion (LVSI; p = 0.015). A total of 26% of the women had a history of tamoxifen usage with no effect seen on survival. Multivariate analysis showed that when treatment modality and LVSI were adjusted for FIGO staging, there was no statistical significance in the survival outcomes.

Conclusion

The incidence of uterine carcinosarcomas is increasing parallel with endometrial carcinomas with no significant effect of tamoxifen on survival.

Pancreatic trauma

INTRODUCTION

Pancreatic trauma occurs in approximately 4% of all patients sustaining abdominal injuries. The pancreas has an intimate relationship with the major upper abdominal vessels, and there is significant morbidity and mortality associated with severe pancreatic injury. Immediate resuscitation and investigations are essential to delineate the nature of the injury, and to plan further management. If main pancreatic duct injuries are identified, specialised input from a tertiary hepatopancreaticobiliary (HPB) team is advised.

METHODS

A comprehensive online literature search was performed using PubMed. Relevant articles from international journals were selected. The search terms used were: 'pancreatic trauma', 'pancreatic duct injury', 'radiology AND pancreas injury', 'diagnosis of pancreatic trauma', and 'management AND surgery'. Articles that were not published in English were excluded. All articles used were selected on relevance to this review and read by both authors.

RESULTS

Pancreatic trauma is rare and associated with injury to other upper abdominal viscera. Patients present with non-specific abdominal findings and serum amylase is of little use in diagnosis. Computed tomography is effective in diagnosing pancreatic injury but not duct disruption, which is most easily seen on endoscopic retrograde cholangiopancreaticography or operative pancreatography. If pancreatic injury is suspected, inspection of the entire pancreas and duodenum is required to ensure full evaluation at laparotomy. The operative management of pancreatic injury depends on the grade of injury found at laparotomy. The most important prognostic factor is main duct disruption and, if found, reconstructive options should be determined by an experienced HPB surgeon.

CONCLUSIONS

The diagnosis of pancreatic trauma requires a high index of suspicion and detailed imaging studies. Grading pancreatic injury is important to guide operative management. The most important prognostic factor is pancreatic duct disruption and in these cases, experienced HPB surgeons should be involved. Complications following pancreatic trauma are common and the majority can be managed without further surgery.

Macrophage subtypes in symptomatic carotid artery and femoral artery plaques

OBJECTIVE

To compare differences in macrophage heterogeneity and morphological composition between atherosclerotic plaques obtained from recently symptomatic patients with carotid artery disease and femoral plaques from patients with severe limb ischemia.

DESIGN

Experimental study.

METHODS

Plaques were obtained from 32 patients undergoing carotid endarterectomy and 25 patients undergoing common femoral endarterectomy or lower limb bypass. Macrophages and T cell numbers were detected in plaque sections by immunohistochemistry and anti CD68 and CD3 antibodies. Dual staining for CD68 and M1- and M2-macrophage markers and morphometric analysis of hematoxylin and eosin stained plaque sections was performed.

RESULTS

Carotid plaques had significantly increased percentage areas of confluent lipid and leukocytic infiltrates. In contrast, areas of fibroconnective tissue were significantly greater in femoral plaques and percentage areas of confluent calcification and collagen were elevated. Carotid artery plaques had greater numbers per plaque area of macrophages and T cells consistent with a more inflammatory phenotype. Proportions displaying M1-activation markers were significantly increased in the carotid compared to femoral plaques whereas femoral plaques displayed a greater proportion of M2-macrophages.

CONCLUSION

Plaques from patients with recently symptomatic carotid disease have a predominance of M1-macrophages and higher lipid content than femoral plaques, consistent with a more unstable plaque.

Adrenocortical oncocytoma: Review of imaging and histopathological implications

Oncocytomas are rare tumours of the adrenal glands whose malignant potential is difficult to assess with certainty. We report a case of an adrenal oncocytoma and present a review of the literature particularly with regards to the radiological and histopathological features and their impact on the management.Adrenal oncocytomas are usually identified incidentally on imaging and can achieve large sizes. They should be considered in the differential diagnosis of any large upper abdominal lesion including those apparently arising from the liver as in this case report. MRI scan appears to be the ideal imaging modality to characterise such lesions. There seems to be little benefit in biopsying these masses and surgery remains the most optimal management. It remains difficult to predict metastatic behaviour based on histological findings and so long term surveillance is advisable.

Ovarian strumal carcinoid--report of a case that matastasized

Ovarian teratomas are known for their ability to form a wide variety of tissues. One unusual example of this potential is the strumal carcinoid in which the thyroid tissue is found in intimate association with carcinoid tumor. Although considered as a malignant transformation of struma ovarii, it is almost always benign. We report a rare case of strumal carcionid in a 44 year old lady who had metastasis in the contralateral ovary, myometrium and lungs.

Strong phase separation in a model of sedimenting lattices

We study the steady state resulting from instabilities in crystals driven through a dissipative medium, for instance, a colloidal crystal which is steadily sedimenting through a viscous fluid. The problem involves two coupled fields, the density and the tilt; the latter describes the orientation of the mass tensor with respect to the driving field. We map the problem to a one-dimensional lattice model with two coupled species of spins evolving through conserved dynamics. In the steady state of this model each of the two species shows macroscopic phase separation. This phase separation is robust and survives at all temperatures or noise levels- hence the term strong phase separation. This sort of phase separation can be understood in terms of barriers to remixing which grow with system size and result in a logarithmically slow approach to the steady state. In a particular symmetric limit, it is shown that the condition of detailed balance holds with a Hamiltonian which has infinite-ranged interactions, even though the initial model has only local dynamics. The long-ranged character of the interactions is responsible for phase separation, and for the fact that it persists at all temperatures. Possible experimental tests of the phenomenon are discussed.