Anesthetic Management of a Massive Cystic Hygroma of the Neck in a Neonate

Cystic hygroma of the neck, a congenital benign tumor of the lymphatic system, is a potential cause of neonatal airway obstruction leading to stridor. Meticulous airway evaluation, case appropriate preparation, and use of advanced technology, including videolaryngoscope and ultrasonography, can facilitate the safe management of the difficult airway.

Automated myocardial infarction and angina detection using second derivative of photoplethysmography

Photoplethysmography (PPG) based healthcare devices have gained enormous interest in the detection of cardiac abnormalities. Limited research has been implemented for myocardial infarction (MI) detection. Moreover, PPG-based detection of angina is still a research gap. PPG signals are not always informative. Therefore, this research work presents the use of PPG signals and their second derivative to evaluate myocardial infarction and angina using a novel set of morphological features. The obtained morphological features are fed onto the feed-forward artificial neural network for the identification of the type of MI and unstable angina (UA). The initial experiments have been carried out on non-ambulatory (public) subjects for feature extraction and later evaluated on ambulatory (self-generated) databases. The intended method attains accuracy, sensitivity, and specificity of 98%, 97%, 98% on the public database and 94%, 94%, 94% on the self-generated database. The result shows that the proposed set of features can detect MI and UA with significant accuracy.

Challenges and outcomes of pregnancy in an uncorrected Tetralogy of Fallot with pulmonary atresia and major aorta-pulmonary collateral arteries (MAPCA): a case report

BACKGROUND

Tetralogy of Fallot is a severe type of congenital heart disease (CHD) and one of the leading indirect causes of mortality & morbidity among women with CHD. We came across a rare case of an uncorrected Tetralogy of Fallot with pulmonary atresia and major aortopulmonary collateral arteries in pregnancy.

CASE PRESENTATION

We are reporting the challenges in managing a pregnancy of 25-years-old G3 P0110, previous one stillbirth and who was diagnosed to have congenital heart disease during pregnancy following spontaneous abortion.

CONCLUSIONS

This case report highlights the role of multidisciplinary care in managing such a high risk case. It also emphasizes the role of cardiac examination of every woman before pregnancy so that definitive treatment or optimization can be done in time for a better outcome.

Recent advances in cardiac anaesthesia

The speciality of cardiac anaesthesia has rapidly evolved over the past few decades with advances in technology, including artificial intelligence (AI), newer devices, techniques, imaging, pain relief and a better understanding of the pathophysiology of disease states. Incorporation of the same has led to improved patient outcomes in terms of morbidity and mortality benefits. With the advent of minimally invasive surgical methods, minimising the dose of opioids and ultrasound-guided regional anaesthesia for pain relief, enhanced recovery after cardiac surgery has been made possible. Perioperative imaging including 3D transoesophageal echocardiography, newer devices and drugs and AI algorithms will play a significant role in cardiac anaesthesia. This review briefly addresses some of the recent advances that the authors believe can impact the practice of cardiac anaesthesia.

Recent advances in research, training and teaching in anaesthesia and critical care

Teaching and learning in anaesthesia and critical care has traditionally included seminars, journal clubs and clinical teaching in the operation theatre. The aim has always been to ignite the spark of thinking and self-directed learning in the students. The process of 'dissertation preparation' introduces basic knowledge and interest in research in the postgraduate student. All this is followed by an examination at the end of the course including the theory and practical assessment in the form of long and short case discussions and table viva-voce. The National Medical Commission in 2019 introduced the competency-based medical education curriculum for anaesthesia postgraduates. This curriculum focuses on structured teaching and learning. It has specific learning objectives in theoretical knowledge, skills and attitude development. The building up of communication skills has been given due importance. Though research in anaesthesia and critical care is steadily progressing, much work needs to be done on its improvement.

Quantitative Assessment of Nitrous Oxide Levels in Room Air of Operation Theaters and Recovery Area: An Observational Study

Background:

Nitrous oxide has been used during surgical anesthesia for many years. However, information about occupational exposure and related risks due to N₂O exposure to the health care personnel in India are still poorly understood. Here, we measured the residual N₂O levels during the working time of operation theatre room air in our tertiary care hospital.

Material and Methods:

The air samples were collected from different anesthesia exposure zones on different days for quantitative analysis of available N₂O in the room air in respective areas. Nitrous oxide concentrations in the ambient air were also measured to compare outdoor and indoor levels.

Observations and Results:

Nitrous oxide mixing ratios were found to be 65.61 ± 0.05 ppm, 281.63 ± 0.43 ppm, and 165.42 ± 0.42 ppm in elective surgical theatres of the hospital on three different days whereas in emergency operation theatres of the same hospital levels of N₂O were 166.75 ± 0.07 ppm, 510.19 ± 0.30 ppm and 2443.92 ± 0.64 ppm during same period. In elective pediatric surgical theatres levels of N₂O were found to be 1132.55 ± 0.70 ppm and 362.21 ± 0.13 ppm on two days of reading respectively. Outdoor levels of N₂O in contrast found 0.32 ± 0.01 ppm and was lower by a factor of 1000.

Conclusion:

We observed the very high ambient concentration of N₂O in the surgical theatre's environment (up to 2443 ppm) and recovery areas (up to 50 ppm). It was 5 to 50 times higher ambient concentration of N₂O than REL in OT area and 200-7000 times higher ambient concentration of N₂O than outdoor ambient air in all surgical theaters other than CTVS OTs.

Limited condylar mobility by ultrasonography predicts difficult direct laryngoscopy in morbidly obese patients: An observational study

Background and Aims

Unpredictable difficult laryngoscopy remains a challenge for anaesthesiologists, especially in morbidly obese patients. The present study aimed to determine the efficacy of different sonographic measures as predictors of difficult laryngoscopy in morbidly obese patients undergoing elective surgery.

Methods

This observational study evaluated 70 morbidly obese adult patients (body mass index >35 kg/m²) undergoing elective surgery under general anaesthesia with tracheal intubation. Pre-operative clinical and ultrasonographic variables (anterior condylar translation, tongue thickness, hyomental distance and oral cavity height) associated with difficult direct laryngoscopy ([Cormack Lehane (CL) grade>2]) were analysed. The primary outcome was to determine the efficacy of the above-mentioned sonographic measures as predictors of difficult laryngoscopy (CL grade >2). The secondary outcome compared ultrasonographic predictors with clinical predictors in morbidly obese patients for determining difficult direct laryngoscopy.

Results

Amongst the primary outcome measures, limited condylar mobility (anterior condylar translation <9.25 mm) [odds ratio (OR) 0.3, confidence interval (CI):1.04-1.22;P<0.001;area under curve (AUC):0.8] and increased tongue thickness >5.85 cm [OR: 3.2, CI: 1.05-10; P < 0.04; AUC: 0.73] were two independent sonographic predictors for difficult direct laryngoscopy by multivariate logistic regression and receiver operating characteristic curve analyses in morbidly obese patients. The secondary outcome suggested that as compared to clinical predictors such as Mallampati grade and thyromental distance, ultrasonographic variables such as tongue thickness and limited condylar mobility (sensitivity: 56.4%, 70.9%, 66.7% and 93.3%, respectively) better predicted difficult direct laryngoscopy in morbidly obese patients.

Conclusion

Limited condylar mobility and increased tongue thickness are independent sonographic predictors of difficult direct laryngoscopy in morbidly obese patients.

Role of α- and β-adrenergic signaling in phenotypic targeting: significance in benign and malignant urologic disease

The urinary tract is highly innervated by autonomic nerves which are essential in urinary tract development, the production of growth factors, and the control of homeostasis. These neural signals may become dysregulated in several genitourinary (GU) disease states, both benign and malignant. Accordingly, the autonomic nervous system is a therapeutic target for several genitourinary pathologies including cancer, voiding dysfunction, and obstructing nephrolithiasis. Adrenergic receptors (adrenoceptors) are G-Protein coupled-receptors that are distributed throughout the body. The major function of α1-adrenoceptors is signaling smooth muscle contractions through GPCR and intracellular calcium influx. Pharmacologic intervention of α-and β-adrenoceptors is routinely and successfully implemented in the treatment of benign urologic illnesses, through the use of α-adrenoceptor antagonists. Furthermore, cell-based evidence recently established the antitumor effect of α1-adrenoceptor antagonists in prostate, bladder and renal tumors by reducing neovascularity and impairing growth within the tumor microenvironment via regulation of the phenotypic epithelial-mesenchymal transition (EMT). There has been a significant focus on repurposing the routinely used, Food and Drug Administration-approved α1-adrenoceptor antagonists to inhibit GU tumor growth and angiogenesis in patients with advanced prostate, bladder, and renal cancer. In this review we discuss the current evidence on (a) the signaling events of the autonomic nervous system mediated by its cognate α- and β-adrenoceptors in regulating the phenotypic landscape (EMT) of genitourinary organs; and (b) the therapeutic significance of targeting this signaling pathway in benign and malignant urologic disease. Video abstract.

Two-Stage Fiberoptic Intubation in an Infant With a Rare Congenital Laryngopharyngo-Cutaneous Fistula: A Case Report

Branchial arches represent embryological precursors of the face, neck, and pharynx, and developmental abnormalities of these branchial arch derivatives can lead to airway anomalies. We report definitive repair of the fistula in an infant with a rare congenital laryngopharyngo-cutaneous fistula. This is the first report that describes a 2-stage fiberoptic intubation, a challenging technique performed for airway management of the aforementioned fistula in a patient with a difficult airway.

Successful surgical management of an aorto-oesophageal fistula caused by button battery ingestion

Aorto-oesophageal fistula is a rare complication of foreign body ingestion from which few patients survive. Aggressive surgical treatment is the only form of effective therapy for this fatal complication. We present the successful surgical treatment of an aorto-oesophageal fistula in a child without using cardiopulmonary bypass.

Erratum: Formation of a Spin Texture in a Quantum Gas Coupled to a Cavity [Phys. Rev. Lett. 120, 223602 (2018)]

This corrects the article DOI: 10.1103/PhysRevLett.120.223602.

Recurrent unilateral hemorrhagic pleural effusion: A rare manifestation of thoracic endometriosis syndrome

Unilateral recurrent pleural effusions are commonly encountered in critical care practice. Relevant clinical history, physical examination, radiology, and diagnostic thoracentesis usually identify the cause of pleural effusion in most cases. Thoracoscopy or video-assisted thoracic surgery may be required in selective cases. We report a case of 32-year-old female with recurrent unilateral hemorrhagic pleural effusion that was the presenting feature of thoracic endometriosis syndrome.

Early thrombolysis is associated with decreased operative mortality in postinfarction ventricular septal rupture

Background

Post myocardial infarction ventricular septal rupture (PMI-VSR) is a dreaded mechanical complication of acute coronary syndromes. Given that surgical mortality approaches 50%, it is pragmatic that the risk factors for mortality and outcomes after surgical correction of PMI- VSR are carefully scrutinized.

Methods

We performed a single-center, retrospective cohort study of 35 patients presenting for surgical closure of post myocardial infarction ventricular septal rupture over six years. We reviewed patient characteristics, clinical, echocardiographic, angiographic and perioperative risk factors which may affect mortality after surgical repair of PMIVSR and 30 day and one year mortality rates of these patients. Univariate and multivariate logistic and cox proportional hazard regression analysis was used to identify predictors of operative and overall mortality. Long term survival was presented with Kaplan-Meier Survival Curve.

Results

Sixteen patients (46%) were in cardiogenic shock. Concomitant coronary artery bypass grafting (CABG) was done in 22 patients (63%) but did not influence survival. Preoperative thrombolysis was done in 12 patients (34%) out of which 10 (53%) survived Operative mortality was 46% and one-year mortality was 49%. Multivariate analysis identified preoperative thrombolysis: Hazards ratio, 0.12; 95% CI, 0.02-0.61; p value of 0.01, as significant independent predictor of survival in PMIVSR cohort.

Conclusions

Preoperative thrombolysis is associated with decreased odds of operative and overall mortality after surgical repair in PMIVSR patients.

Formation of a Spin Texture in a Quantum Gas Coupled to a Cavity

We observe cavity mediated spin-dependent interactions in an off-resonantly driven multilevel atomic Bose-Einstein condensate that is strongly coupled to an optical cavity. Applying a driving field with adjustable polarization, we identify the roles of the scalar and the vectorial components of the atomic polarizability tensor for single and multicomponent condensates. Beyond a critical strength of the vectorial coupling, we infer the formation of a spin texture in a condensate of two internal states from the analysis of the cavity output field. Our work provides perspectives for global dynamical gauge fields and self-consistently spin-orbit coupled gases.

Isolated pericardial echinococcosis: Perioperative transesophageal echocardiographic evaluation

Hydatid cyst (HC) is a human parasitic disease caused by the larval stage of Echinococcus granulosus. Cardiac involvement is rare and occurs in 0.5%-2% of patients with hydatid cyst, but isolated pericardial hydatid cyst is rarer still. We present two cases of isolated pericardial hydatid cyst who presented with precordial chest pain and dyspnea. In both the cases, HC were diagnosed by transthoracic echo (TTE), Computed Tomography/Magnetic Resonance and positive hydatid serology. Intraoperatively transesophageal echo (TEE) revealed unilocular transitional cystic lesion the transverse pericardial sinus in one case and multilobulated active cystic lesion in another. The report highlights the role of TEE in diagnosis and evaluation of cardiac HC. Both the cases underwent surgical resection followed by albendazole therapy to prevent recurrence.

Glucose-6-phosphate dehydrogenase deficiency and cardiac surgery

Cardiac surgery involving cardiopulmonary bypass (CPB) in its conventional form involves many processes leading to free radical production, such as perioperative ischemia, reperfusion, circulation of whole body blood through the CPB circuit, hypothermia and acidosis. The red blood cells of a glucose-6-phosphate dehydrogenase (G6PD)-deficient person are unable to scavenge these free radicals, resulting in haemolysis. Here, we describe the successful anaesthetic management of two G6PD-deficient children who underwent cardiac surgery, on and off CPB, without any obvious haemolytic reaction, followed by a discussion of the disorder, with specific consideration of perioperative management of such cases.

Children's specific fears

BACKGROUND

Most children experience some degree of fear during their development. Specific fears are considered as an appropriate response provided that they are proportionate to the intensity of the perceived threat. Our aim is to present the prevalence of specific fears among children in the Great Britain, their socio-demographic correlates, in particular their association with ethnicity.

METHODS

Data on the child's experience of specific fears were obtained from parents of a national representative sample of 5- to 16-year-olds using the Development and Well-Being Assessment. Biographic, socio-demographic and socioeconomic characteristics of the child and the family were included in the questionnaire.

RESULTS

About one-third of children were assessed by their parents as having at least one of 12 specific fears. The most commonly reported fears were animals (11.6%), blood/injections (10.8%) and the dark (6.3%). Just less than 1% of all children were assessed according to International Classification of Diseases research diagnostic criteria as having a specific phobia. Biographic, socio-demographic and socioeconomic factors were independently associated with a greater likelihood of a child having particular fears. The most marked associations were fears of the dark, loud noises, imagined supernatural beings in younger children and fear of animals among girls and all non-white groups.

CONCLUSIONS

Although fears are only labelled as phobias when they impair functioning and interfere with life, they can cause personal distress to children and also can interfere with their daily activities. Children's fears differ in nature across different ethnic groups. Culturally mediated beliefs, values and traditions may play a role in their expression.

Attitudes of preclinical medical students towards caring for chronically ill and dying patients: does palliative care teaching make a difference?

INTRODUCTION

Students entering medical school today will encounter an ageing population and a higher incidence of diseases affecting the elderly-for example, chronic respiratory and cardiac disease and malignancy.

PURPOSE

This study was carried out to determine the attitudes of preclinical medical students towards the care of patients for whom a cure is not possible.

METHODS

All students were invited to complete a 23 item questionnaire prior to initial teaching and again following the second teaching session in palliative care.

RESULTS

Overall, 149 of the 186 students (80%) completed the pre-teaching questionnaire (59 males and 90 females; median age 20 years, range 19-27 years), and 66 students (35%) completed the post-teaching questionnaire. Attitudes towards chronically ill and dying patients were generally positive. It was found that increasing age was associated with a more positive view of caring for patients with chronic or terminal illness, a more positive view of listening to patients reminisce, and a more positive view of patients dying at home (p = 0.014). The only notable result was that after palliative care teaching students had a significantly more positive view of hospices.

CONCLUSION

Caring for patients at the end of life can be one of the most rewarding aspects of being a doctor. This study suggests that the majority of medical students have a positive attitude towards patients with chronic incurable illness, and the trend for encouraging older students to enter medicine may be an influencing factor.

Congenital generalized cutis laxa in two sisters

Two sisters, aged 2 and 3 years, having generalized cutis laxa, presenting with progressive loose pendulous skin since birth are reported.

In vitro effects of cAMP-elevating agents and glucocorticoid either alone or in combination on the production of nitric oxide, interleukin-12 and interleukin-10 in IFN-gamma- and LPS-activated mouse peritoneal macrophages

The effects of cAMP-elevating agents, N6-2'-O-dibutyryl cAMP (Bu2cAMP), and glucocorticoid (dexamethasone) on the production of inflammatory mediators--nitric oxide and interleukin-12 (IL-12) and anti-inflammatory mediator interleukin-10 (IL-10) were demonstrated in murine peritoneal macrophages. Inducible nitric oxide synthase (iNOS) and iNOS mRNA were detected by northern blot and western blot, respectively. The cAMP elevating agents Bu2cAMP and prostaglandin E2 each alone did not show any effect on NO production but along with IFN-gamma and lipolysaccharide (LPS) they slightly enhanced NO production. Dexamethasone inhibited NO production in IFN-gamma- and LPS-treated cells; cAMP elevating agents interfered with the NO production inhibited by dexamethasone. Inhibition was revealed at the mRNA level as well as at protein level. Bu2cAMP or dexamethasone either alone or synergistically inhibited IL-12 production; Bu2cAMP interfered with dexamethasone-mediated inhibition of IL-10 production in IFN-gamma- and LPS-treated macrophages. The use of glucocorticoids along with cAMP elevating agents was beneficial in lowering the level of inflammatory mediator IL-12 and producing high levels of the anti-inflammatory mediator IL-10 active in cell protection. On the other hand, interference of Bu2cAMP with dexamethasone-mediated NO inhibition may have adverse effect. Therefore, adverse effects due to cAMP-mediated interference (inhibition) with NO synthesis may occur in many inflammatory diseases during combined drug therapy by glucocorticoids and cAMP elevating agents.

The development and evaluation of a programme to teach cultural diversity to medical undergraduate students

This paper describes the design (of process and content), implementation and evaluation of a component of the Human Diversity Module developed to teach cultural diversity to undergraduate medical students. The objectives of the teaching were to enable students to gain factual and practical information about other cultures and also for them to examine their own attitudes.

METHOD

Students completed a questionnaire, designed in a previous study, at two stages; the first before the component on cultural diversity had been delivered and the second after the sessions on cultural diversity. The time interval between stages 1 and 2 was 1 week. The cultural diversity component was developed using a range of sources.

RESULTS

Out of 181 students, 140 (77.3%) completed the questionnaire at both stages. There were a number of statistically significant findings, which indicate that the teaching enabled the session objectives to be successfully met. The findings include statistically significant changes that reflect more "positive" attitudes about cultures coming together and about specific cultures.

CONCLUSION

The study indicates that attitudes changed over the period of teaching. There is, however, scope for further development of measures to enable attitudinal shifts to be evaluated.

Steroid biotransformation by different strains of Micrococcus sp

A strain of Micrococcus sp. was isolated for its capability of side chain degradation of cholesterol. This strain was characterized and identified as Micrococcus roseus. It was found to be the best strain for the production of androsta-1,4-diene-3,17-dione and androst-4-ene-3,17-dione compared with other Micrococcus strains.

Effects of prostaglandin E2 and nitric oxide inhibitors on the expression of interleukin-10, interleukin-12 and MHC class-II molecules in Mycobacterium microti-infected and interferon-gamma-treated mouse peritoneal macrophages

Mycobacterium microti-infected mouse peritoneal macrophages produced high amounts of prostaglandin E2 (PGE2) and nitric oxide (NO) when activated with interferon-gamma (IFN-gamma). In order to understand the relation between PGE2 and NO production and the expression of interleukin-12 (IL-12), interleukin-10 (IL-10) and MHC class-II (Ia) molecules by M. microti-infected and IFN-gamma-stimulated macrophages, we analyzed the level of these molecules in the presence or absence of PGE2 and NO inhibitors. Addition of NG-methyl-L-arginine (L-NMA) and indomethacin (IM) caused a significant increase in IL-12 level (2.6- and 1.9-fold, respectively) whereas IL-10 level decreased by 88 and 56%, respectively, relative to M. microti-infected and IFN-gamma-treated control macrophages. Enhanced PGE2 and NO upregulated IL-10 expression and down-regulated IL-12 and MHC class-II (Ia) expression in M. microti-infected and IFN-gamma-treated mouse peritoneal macrophages.

Characteristics of children and adolescents presenting to accident and emergency departments with deliberate self harm

OBJECTIVES

The aim of this study was to provide a description of the characteristics of children and adolescents presenting to the accident and emergency (A&E) department with deliberate self harm.

METHODS

Descriptive analysis of data collected by reviewing the notes of all children and adolescents aged 16 years and under, presenting during the period of study (1 January to 31 December) with a history of deliberate self harm.

RESULTS

A total of 100 children (18 boys, 82 girls) were responsible for 117 episodes of deliberate self harm. Nine repeaters were responsible for 22% of the attendances; 38% had made use of emergency ambulance service and 6% were referred by their general practitioner (GP). Sixty nine per cent were accompanied by immediate family and 21% children presented alone. Seventy four per cent presented within three hours of the attempt and 37% presented between 6 pm and midnight; 77% presented during weekdays and 30% of attempts had occurred during spring. Ninety two per cent had used a pharmaceutical drug. Sixty five per cent had made the attempt at home and 12% in a public place. Twenty five per cent had prior or current contact with the child psychiatric services and a similar proportion had prior or current contact with social services.

CONCLUSIONS

Few of the children and adolescents presenting with deliberate self harm to the A&E department have been referred by their GP. They frequently present alone or are accompanied by people who are not family members making assessment and treatment difficult. Many already have other services involved in their care and thus the gathering and dissemination of information can become quite lengthy. The time of presentation is usually out of hours, further complicating this process. A small number of young people present with repeated self harm, who are known to be most vulnerable for completing suicide.

Interferon-gamma- and lipopolysaccharide-induced tumor necrosis factor-alpha is required for nitric oxide production: tumor necrosis factor-alpha and nitric oxide are independently involved in the killing of Mycobacterium microti in interferon-gamma- and lipopolysaccharide-treated J774A.1 cells

A comparative study was done using J774A.1 and J774A.1-derived transfected cells (J774A.1 C.1) containing antisense tumor necrosis factor alpha (TNF-alpha) plasmid to determine the role of endogenous TNF-alpha on nitric oxide production as well as on the growth of Mycobacterium microti in interferon gamma (IFN-gamma)- and lipopolysaccharide (LPS)-treated cells. On stimulation with IFN-gamma and LPS a higher level of NO was observed in J774A.1 cells compared to J774A.1 C.1 which indicated that endogenous TNF-alpha is required for the production of NO. Comparing the effect of IFN-gamma and LPS on the intracellular growth of M. microti, the growth-reducing activity was higher in J774A.1 cells than in J774A.1 C.1 cells and was not completely abrogated in the presence of the nitric oxide inhibitor NG-methyl-L-arginine (L-NMA). J774A.1 C.1 cells infected with M. microti produced a significant amount of NO when exogenous TNF-alpha was added along with IFN-gamma and LPS and the concentration of intracellular bacteria decreased almost to that in IFN-gamma and LPS treated parental J774A.1 cells. Addition of exogenous TNF-alpha even in the presence of L-NMA in J774A.1 C.1 cells could also partially restore intracellular growth inhibition of M. microti caused by IFN-gamma and LPS. TNF-alpha is probably required for the production of NO in J774A.1 cells by IFN-gamma and LPS but TNF-alpha and NO are independently involved in the killing of intracellular M. microti with IFN-gamma and LPS.

The development of an undergraduate course in child psychiatry

This paper begins with a brief review of child psychiatry teaching to undergraduate medical students.Teaching methods are also considered.The development of the current child psychiatry course at the University of Leicester is then described. This falls naturally into three stages from the beginning of the project to improve on the previous course. For clarity, the results are presented separately for each stage. The changes from one stage to the next and the rationale for these changes are presented in the overall discussion. The final section considers the present position and how we can further develop the clinical child psychiatry teaching programme.

Attempts to characterize the mechanisms involved in the growth inhibition of Mycobacterium microti in interferon-gamma or tumor necrosis factor-alpha activated J774A.1 cells

The growth of Mycobacterium microti was inhibited within J774A.1 macrophage cells activated with either interferon-gamma or tumor necrosis factor-alpha. Activation with interferon-gamma or tumor necrosis factor-alpha alone did not stimulate the production of nitrite in J774A.1 cells. Interferon-gamma but not tumor necrosis factor-alpha increased the production of hydrogen peroxide in a concentration dependent manner but scavengers of reactive oxygen species did not influence the growth inhibiting effect of interferon-gamma within J774A.1 cells. Both interferon-gamma and tumor necrosis factor-alpha enhanced the fusion of M. microti containing phagosomes with lysosomes and the ultimate degradation of bacteria. Our results showed that growth inhibition of M. microti within interferon-gamma or tumor necrosis factor-alpha stimulated J774A.1 cells was independent of reactive oxygen intermediate and reactive nitrogen intermediate production.