Reaction-driven oscillating viscous fingering.

Localized oscillations can develop thanks to the interplay of reaction and diffusion processes when two reactants A and B of an oscillating reaction are placed in contact, meet by diffusion, and react. We study numerically the properties of such an A+B→ oscillator configuration using the Brusselator model. The influence of a hydrodynamic viscous fingering instability on localized concentration oscillations is next analyzed when the oscillating chemical reaction changes the viscosity of the solutions involved. Nonlinear simulations of the related reaction-diffusion-convection equations with the fluid viscosity varying with the concentration of an intermediate oscillatory species show an active coupling between the oscillatory kinetics and the viscously driven instability. The periodic oscillations in the concentration of the intermediate species induce localized changes in the viscosity, which in turn can affect the fingering instability. We show that the oscillating kinetics can also trigger viscous fingering in an initially viscously stable displacement, while localized changes in the viscosity profile can induce oscillations in an initially nonoscillating reactive system.

Primary adrenal teratoma: An unusual tumor - Challenges in diagnosis and surgical management.

We report a rare case of a 25-year-old lady who presented with right hypochondriac pain associated with weakness for 3 months. Her hormonal evaluation was normal. Computed tomography scan revealed an adrenal mass for which a right open transperitoneal adrenalectomy was performed, and the lesion was diagnosed as mature teratoma on histopathological examination. Teratoma is an unusual neoplasm which arises from one or all the three germ layers. Extragonadal teratomas are rare in adults as compared to children and are mostly retroperitoneal in location, constituting only 4% of all primary teratomas. Primary adrenal teratomas are even rarer and to the best of our knowledge, only eight cases have been reported in adults in the past 10 years. Adrenal teratoma can pose a diagnostic challenge because radiologically it mimics myelolipoma, angiomyolipoma, liposarcoma, or pheochromocytoma. Mature teratomas are usually benign but may possess malignant potential, the chances of which are greater in adults as compared to children, making it an important entity requiring a proper diagnosis and management.

Robotic-assisted deep inferior epigastric artery perforator flap abdominal harvest for breast reconstruction: A case report.

The deep inferior epigastric perforator (DIEP) flap is a mainstay of autologous breast reconstruction. The da Vinci robot has recently been adapted for an increasing number of reconstructive surgeries. The literature has yet to describe its use for the intra-abdominal harvest of the deep inferior epigastric vessels (DIEV) during DIEP flap breast reconstruction. We show the use of the da Vinci robotic surgical system for the intra-abdominal dissection of DIEV during delayed breast reconstruction with a DIEP flap in a 51-year-old female who had undergone a right modified radical mastectomy. After dissecting the flap from the anterior abdominal wall leaving only the targeted perforating vessels intact, a 1.5 cm fascial incision was made adjacent to the perforator and the vessels were dissected to below the level of the fascia. The intra-abdominal robotic-assisted dissection of the DIEV up to the perforator was then completed. The DIEV were divided at their origin using the robot and the flap removed from the abdomen for subsequent reconstruction. This technique enabled improved precision of flap harvest while also decreasing the donor-site morbidity by minimizing the incision length of the anterior rectus sheath. The patient had an uneventful postoperative course and, at 9-month follow-up, exhibited no evidence of flap or donor-site complications, specifically hernia or bulge. This novel approach for the harvest of a DIEP flap introduces an alternative technique to the conventional DIEP flap procedure in the appropriate patient population. Risks inherent to this technique as well as additional costs must be considered.

Descriptive study of earthquake-related spinal cord injury in Nepal.

STUDY DESIGN: Descriptive study. OBJECTIVES: To describe the epidemiological features of spinal cord injury (SCI) following the 2015 earthquakes in Nepal. SETTING: Spinal Injury Rehabilitation Centre, Kavre, Nepal. METHODS: Data were collected from the medical records of all earthquake-related patients seen from 25 April 2015 through to 16 June 2016. Data collected included patient demographics, mechanism of injury, initial medical treatment, neurological assessment, complications, neurological/functional outcomes and length of stay. RESULTS: Data from 117 earthquake-related SCI patients were evaluated, with a female-to-male ratio of 1.3:1. In total, 108 patients (92%) sustained vertebral fracture and/or dislocation. Seventy-seven patients had undergone surgical fixation. The majority of patients (81%) presented with paraplegia, of whom most (60%) were incomplete. Thirty-eight (33%) patients had documented pressure ulcers upon admission; six (5%) patients developed new pressure ulcers during their rehabilitation stay. Urinary tract infection was seen in 34 (29%) patients. Seven (6%) patients were diagnosed with deep vein thrombosis. One patient developed clinically significant heterotopic ossification. Significant improvements were seen in patients' functional outcomes before discharge. Two deaths occurred in this patient population. CONCLUSIONS: The Nepal earthquakes resulted in a significant number of SCIs, the majority occurring in women. Incomplete paraplegia was the most common presentation. Pressure ulcer, the most frequent complication, primarily occurred before rehabilitation admission. Continued efforts focused on comprehensive planning, and preparedness for SCI-specific interdisciplinary care following earthquakes, particularly in resource-limited settings, is critical to ensuring survival, preventing complications and optimizing functional outcomes in this patient population.

Ultrasound-guided fine needle aspiration cytology of gallbladder lesions: a study of 596 cases.

OBJECTIVE: Fine needle aspiration (FNA) is not a commonly performed procedure for gallbladder lesions for fear of causing biliary peritonitis; hence data on gallbladder cytology is scarce. The aims of the present study were to evaluate the diagnostic application of ultrasound-guided (US) FNA cytology in the pre-operative diagnosis of neoplastic as well as non-neoplastic lesions of the gallbladder and to review the cytomorphological spectrum of gallbladder lesions encountered along with various diagnostic difficulties that can arise during reporting. METHODS: The study was carried out on 596 patients with gallbladder lesions in whom US-guided FNA was performed over a 5-year period. In 130 cases, simultaneous aspirations from other organs were done. The histological correlation was available in 32 cases. No major complications such as haemorrhage, peritonitis, etc. were encountered related to the procedure. RESULTS: The majority were mass lesions whereas in 73 cases (12.2%) only focal or diffuse gallbladder wall thickening was present. Cytological examination of 596 cases revealed malignancy in 462 (77.6%), 26 (4.4%) suspicious of malignancy, 23 (3.8%) inflammatory lesion, 29 negative (4.8%) and 56 cases showed necrosis only or were inadequate for any definite opinion. The lesions diagnosed on FNA cytology included carcinoma (predominantly adenocarcinoma), xanthogranulomatous cholecystitis (XGC), acute suppurative inflammation and tuberculosis. Of 26 with adequate cytology, 24 were accurate with respect to malignant (including one suspicious FNA) versus benign: one false positive and one false negative both involved xanthogranulomatous change. CONCLUSION: The present study is the largest series evaluating the role of US-guided FNA in the diagnosis of gallbladder lesions. It is a safe, rapid, reliable, cost-effective and reasonably accurate method for diagnosing gallbladder lesions. FNA should always be attempted in cases with a mass lesion.

Laparoscopic repair of gastro-duodenal fistula secondary to band erosion.

Laparoscopic gastric banding is one of the most common surgical treatments for morbid obesity performed worldwide. The procedure, however, has many well-documented risks and complications, including band erosion. We present here a gastric banding patient who was referred to our tertiary care centre after secondarily forming an entero-enteric fistula with complaints of pain, nausea, vomiting and severe reflux. She was successfully treated with laparoscopic dissection and due to her existing anatomy, and the patient's desire for continued weight loss, she was converted to Roux-en-Y gastric bypass.

Intraoperative squash cytology: accuracy and impact on immediate surgical management of central nervous system tumours.

OBJECTIVE: To assess the diagnostic accuracy of squash cytology, reasons for deferment, disagreement and partial agreement, and assess its impact on immediate surgical management of central nervous system tumours. STUDY DESIGN: All cases of squash cytology received from January 2007 to July 2010 were reviewed and correlated with final histopathological diagnoses. Deferments, disagreements and partial disagreements were reviewed to look for possible reasons. The impact of disagreements and partial agreements on immediate surgical management was evaluated in consultation with neurosurgeons. RESULTS: Overall accuracy (including complete and partial agreement) for squash smear diagnosis of 334 cases was 94.9% while complete agreement was 79.9%, excluding deferred cases. Disagreement was seen in 17 cases and 31 cases were deferred for final histopathology diagnosis. Good correlation was seen in astrocytoma, meningioma, schwannoma, medulloblastoma, pituitary adenoma and metastatic carcinoma, whereas poor correlation was seen in oligodendroglioma, ependymoma and lymphoma. Among 17 cases with disagreement and 50 cases with partial agreement, an adverse impact on immediate surgical management was found in six (35.3%) cases and one (2.0%) case, respectively. The sensitivity and specificity of squash for diagnosis of neoplastic lesions were 98.7% and 87.5%, respectively. CONCLUSION: Squash cytology is a rapid, reliable, simple technique for intraoperative consultation in neurosurgical practice with high overall accuracy. Causes causing an adverse impact on surgical management were rare and potential avoidable reasons for them were identified.

Intracranial germ cell tumors at unusual locations.

Germ cell tumor (GCT) is relatively uncommon in intracranial locations. They constitute ~ 0.3-0.6% of intracranial neoplasms and encompass a wide pathologic range. The majority occurs in young adults and occupies the midline locations like pineal gland followed by suprasellar compartment. These tumors are rare in the cerebral hemisphere, basal ganglia, thalamus and ventricles. Neuroimaging studies cannot differentiate GCTs from other tumors, and therefore, the diagnosis usually requires histological confirmation. Germ cell tumors can be divided into major groups including germinomas and nongerminomatous GCTs (NGGCTs). Their proper identification as well as histopathological typing is important as treatment and prognosis vary greatly between different groups. Germinomas have a superior prognosis and are more radiosensitive as compared to non-germinomatous germ cell tumors. Standard management is still controversial. In this case series we are presenting three cases of intracranial germ cell tumors arising in two unusual locations, that is intraventricular and thalamic region. Apart from the clinical, radiological, histopathological and surgical details we also discuss the various aspects of intracranial germ cell tumors.

Gastrojejunocolic fistula: case report of a rare late complication of laparoscopic Roux-en-Y gastric bypass and review of the literature.

INTRODUCTION: Laparoscopic Roux-en-Y gastric bypass (LRYGB) is known as the weight loss surgery to which other bariatric procedures are compared. While morbidity and mortality of this procedure are low, serious complications do exist which can be life-threatening and sometimes require surgical correction. CASE PRESENTATION: A 63-year-old woman underwent LRYGB outside of the United States, later complicated by biliary colic treated with cholecystectomy and upper gastrointestinal bleeding secondary to H. pylori-related ulcer at her gastrojejunostomy. Following adequate treatment of the patients marginal ulcer, the patient experienced several months of progressive severe abdominal pain, frequent vomiting and diarrhea, and unintentional weight loss refractory to pharmacologic therapy. The patient underwent multiple medical and endoscopic evaluations unrevealing of an organic cause of her symptoms. At presentation, the patient was found to be profoundly weak, dehydrated and malnourished with metabolic derangements and was subsequently diagnosed with a gastrojejunocolic fistula via upper endoscopy and radiography. We provided excluded stomach gastrostomy tube feeding to the patient for three months to improve the patients nutritional status before definitive surgical correction was successfully performed. DISCUSSION: Large bowel fistulas are a rare and highly morbid late complication following LRYGB and are likely secondary to marginal ulcers and/or instrumentation such as endoscopy. Surgery represents the definitive treatment. CONCLUSION: LRYGB is typically a safe and effective intervention for obesity. Large bowel fistulas are rare complications following this surgery. We highlight difficulties in diagnosing and treating this condition.

Systematic review of transgastric ERCP in Roux-en-Y gastric bypass patients.

Balloon-assisted endoscopic retrograde cholangiopancreatoscopy (ERCP) in Roux-en-Y gastric bypass (RYGB) patients is technically challenging due to anatomic and accessory constraints, thus success rates are modest. Transgastric ERCP (TG-ERCP) offers a viable alternative. We aimed to systematically review the literature on TG-ERCP in RYGB patients to better define the technical approaches, success rates, and adverse events of this procedure. A computer-assisted search of the Embase and PubMed databases was performed to identify studies that focused on the techniques and clinical outcomes of TG-ERCP. Two investigators independently identified studies and abstracted relevant data. The literature search yielded 26 eligible studies comprising 509 TG-ERCP cases. Access to the excluded stomach to facilitate ERCP was achieved laparoscopically in 58% of reported cases, via open surgery (6% of reported cases), by antecedent placement of a percutaneous gastrostomy tube (33%), or with endoscopic ultrasound assistance (3%). Successful gastric access was reported in 100% of cases and successful ductal cannulation in 98.5%. Adverse events were reported in 14% of cases; 80% of these were related to gastrostomy creation and the rest were attributable to ERCP. Wound infections (n = 19, 3.7%) were the most common gastrostomy-related adverse event, and post-ERCP pancreatitis (n = 7, 1.4%) was the most common ERCP-related adverse event. No deaths were reported. Based on existing observational studies, TG-ERCP appears to be a safe and highly effective approach in patients with RYGB anatomy. Additional research and clinical experience are needed to more precisely define the risk-benefit ratio and optimal technique of TG-ERCP.

Comparison of fleroxacin and amoxicillin in the treatment of uncomplicated urinary tract infections in women.

Fleroxacin, 400 mg, was compared with amoxicillin, 3,000 mg, each administered orally in a single dose, for the treatment of women with acute uncomplicated symptomatic urinary tract infections. A total of 142 patients were randomized to receive fleroxacin, and 147 patients to receive amoxicillin. Of these, 33 in the fleroxacin group and 39 in the amoxicillin group were considered bacteriologically evaluable. Cure at 5-9 days after treatment was achieved in 32 (97%) of the fleroxacin-treated patients and in 22 (56%) of the amoxicillin-treated patients (p < 0.001). For the most frequently isolated pathogen (Escherichia coli), all 24 isolates were eradicated in the fleroxacin group, as were 11 of 25 in the amoxicillin group. At 6 weeks after therapy, bacteriologic cure was maintained in 20 (95%) of the 21 evaluable patients who received fleroxacin and in 8 (89%) of 9 evaluable patients who received amoxicillin. There were no reinfections in either group. A total of 280 patients were assessed for safety. Clinical adverse events were reported in 32 (23%) of 137 patients in the fleroxacin group and in 19 (13%) of the 143 patients in the amoxicillin group. In both groups, the most common adverse effects were gastrointestinal, while adverse events involving the central nervous system were more frequent in patients who received fleroxacin. On the basis of this study, it appears that fleroxacin is demonstrably more effective than amoxicillin as single-dose therapy for uncomplicated urinary tract infection.

Interactions between personal expectations and naloxone: effects on tolerance to ischemic pain.

Sixteen healthy subjects participated in an investigation of the interactive effects of naloxone and personal expectations of control, stress, and anxiety, on time tolerance to ischemic pain. Control and anxiety levels provided no significant naloxone-saline discriminations, but there was a significant interaction between stress levels and naloxone-induced reduction in tolerance to ischemia. This finding suggests that activity in the opiate system may be a function of the modifying influences of variable attitudes to environmental stress. A primary analgesic role for the endorphins is challenged, however, by the findings that tolerance levels failed to reveal naloxone reactors and stress levels were not significantly associated with differences in tolerance. The latter, on the other hand, correlated significantly with control and anxiety levels, indicating that further research is needed to clarify the complex relationship between these three variables and their effects on the modulation of pain perception.

Reactions to ischemic pain: interactions between individual, situational and naloxone effects.

Fifty-two paid volunteers participated in two separate factorial investigations of the effects of naloxone on time tolerance of and affective reactions to ischemia, as a function of the interaction between expectations of involvement in the experimental situation and experimental variables involving stress or suggestions of analgesia. Naloxone-induced reduction in tolerance to ischemia interacted significantly with the level of involvement expectancies. The suggestion of analgesia provided no significant naloxone-saline discrimination, but there was a significant interaction between variable memory task conditions and drug effects on the time ischemia was tolerated. These findings suggest that naloxone-opiate receptor interactions may depend on individual differences in attitudes to the situation, but may be potentiated by select environmental stimuli. Analyses of the effects of treatment on affective reactions to ischemia failed to show consistent results.

Purine modulation of cytokine release during diuretic therapy of rheumatoid arthritis.

Since free radicals are implicated in rheumatoid arthritis (RA) and since uric acid is a free radical scavenger, we examined the effects of treating RA patients with with the diuretic bumetanide to try to improve their arthritic control. Seventy patients, aged 18-75 years, were randomised to receive bumetanide 4 mg/day or placebo. Uric acid levels increased, but not that of other purines, in the blood of drug-treated patients compared with placebo-treated controls. There were no significant changes in clinical measurements of disease activity or in ESR or CRP levels. There were no over all differences in the blood levels of the cytokines, nor in the basal or stimulated production of cytokines from the blood cultures. The adenosine receptor agonist 5'N-ethylcarboxamido-adenosine (NECA) used to modify cytokine release in cultures of whole blood taken from the patients, depressed the release of tumour necrosis factor-alpha (TNFalpha), but failed to depress the release of interleukin-1b (IL-1b) or interleukin-6 (IL-6), a difference from earlier studies of healthy control subjects and, thus, a difference which may contribute to the disease activity.

Three day treatment of vaginitis with econazole nitrate cream.

The cure rate of a short term twice daily therapy for vulvovaginal infection caused by Candida albicans is shown to be comparable with the results of longer courses of treatment. Three quarters of patients studied approved of the twice daily therapy.

The Diagnostic Significance of a Mucocele of the Appendix.

Appendiceal mucoceles are rare lesions with a variable clinical presentation often identified incidentally on imaging or at laparotomy/laparoscopy for an unrelated diagnosis. Mucocele of the appendix may be a benign or malignant process, making early recognition based on symptoms and key radiographic characteristics of the utmost importance for optimal patient management. Here we present the case of a patient presenting with non-specific abdominal complaints suffering from appendiceal mucocele perforation due to low-grade mucinous adenocarcinoma.

Plasma cell myeloma in a renal transplant recipient: A case report and review of literature.

Post-transplant lymphoproliferative disorders are mostly B-cell neoplasms that develop as a consequence of immunosuppressive therapy. Plasma cell myeloma occurring after solid organ transplant is rare. We report here a case of plasma cell myeloma variant of post-transplant lymphoproliferative disorders developing after 15 months of live related renal transplant in a 41-year-old female. We compare clinicopathological features of this case with few cases reported in literature.