Healthy lungs tolerate repetitive collapse and reopening during short periods of mechanical ventilation

The possible occurrence of lung damage if alveolar units are allowed to collapse and reopen breath by breath during mechanical ventilation with normal tidal volumes was investigated. Anaesthetised, paralysed, open chest rabbits were subjected to either intrathoracic negative (NEEP; n=6) or positive (PEEP; n=6) end-expiratory pressure during volume controlled mechanical ventilation. Both experimental settings were preceded by a 30 min control period and followed by a 30 min recovery period during which a PEEP of 0.2 kPa was maintained. Pao₂ and pulmonary compliance deteriorated significantly in the NEEP group during the experimental period and compared to ventilation with PEEP. Partial restoration of lung mechanics and blood gases was achieved during the recovery period. After an alveolar recruitment manoeuvre, this recovery was complete. Lung clearance studied by depositing an aerosol of technetium-99m-labelled diethylenetriamine pentaacetate (^99mTc-DTPA) in the alveoli, was significantly faster during ventilation with NEEP compared to the PEEP group ( P =0.0002) as well as the control period ( P = 0.0029). It did not recover completely during the recovery period but remained significantly faster. light microscopic histology was normal in both groups with no evidence of inflammation or epithelial disruption. We conclude that previously healthy rabbit lungs show only a transient disturbance of lung mechanics and blood gases with repetitive collapse and re-expansion. The integrity of the alveolar rnicrostructure is preserved. The disturbance in the alveolo-capillary permeability persists and may indicate surfactant related alveolo-capillary barrier dysfunction.     

A conservative surgical approach for management of iatrogenic pulmonary artery perforation

Accidental malposition of a chest tube in the pulmonary artery is a potentially fatal complication. Here we describe a 66 year-old obese woman with prior cardiac transplantation, intubated for respiratory failure and felt to have a large left pleural effusion. A chest tube was inserted using a trocar tube, and resulted in near-exsanguinating hemorrhage immediately, with development of hypovolemic shock. Prompt clamping of the tube proved life-saving, and CT scan confirmed placement of the tube in the main pulmonary artery. Initial stabilization, followed by a planned surgical approach, resulted in successful removal of the tube.     

Diffusion tensor imaging analysis of rheumatoid arthritis patients with neuropsychiatric features to determine the alteration of white matter integrity due to vascular events

Clinical Rheumatology - The pathophysiology of neuropsychiatric manifestations in rheumatoid arthritis is not well known. The magnetic resonance imaging of the brain in rheumatoid arthritis...     

Formulation Development,Optimization, and In Vitro–In Vivo Characterization of Natamycin-Loaded PEGylated Nano-Lipid Carriers for Ocular Applications

The present study aimed at formulating and optimizing natamycin (NT)-loaded polyethylene glycosylated nano-lipid carriers (NT-PEG-NLCs) using Box-Behnken design and investigating their potential in ocular applications. Response surface methodology computations and plots for optimization were performed using Design-Expert^® software to obtain optimum values for response variables based on the criteria of desirability. Optimized NT-PEG-NLCs had predicted values for the dependent variables which are not significantly different from the experimental values. NT-PEG-NLCs were characterized for their physicochemical parameters; NT's rate of permeation and flux across rabbit cornea was evaluated, in vitro, and ocular tissue distribution was assessed in rabbits, in vivo. NT-PEG-NLCs were found to have optimum particle size (<300 nm), narrow polydispersity index, and high NT entrapment and NT content. In vitro transcorneal permeability and flux of NT from NT-PEG-NLCs was significantly higher than that of Natacyn^®. NT-PEG-NLC (0.3%) showed improved delivery of NT across the intact cornea and provided concentrations statistically similar to the marketed suspension (5%) in inner ocular tissues, in vivo, indicating that it could be a potential alternative to the conventional suspension during the course of fungal keratitis therapy.     

Robotic Kidney Transplantation with Regional Hypothermia: A Step-by-step Description of the Vattikuti Urology Institute–Medanta Technique (IDEAL Phase 2a)

Background

We recently reported on preclinical and feasibility studies (Innovation, Development, Exploration, Assessment, Long-term study [IDEAL] phase 0–1) of the development of robotic kidney transplantation (RKT) with regional hypothermia. This paper presents the IDEAL phase 2a studies of technique development.

Objectives

To describe the technique of RKT with regional hypothermia developed at two tertiary care institutions (Vattikuti Urology Institute and Medanta Hospital). We report on the safety profile and early graft function in these patients.

Design, setting, and participants

This is a prospective study of 50 consecutive patients who underwent live-donor RKT at Medanta Hospital following a 3-yr planning/simulation phase at the Vattikuti Urology Institute. Demographic details, and perioperative and postoperative outcomes are reported for the initial 25 recipients who have completed a minimum 6-mo follow-up.

Surgical procedure

Positioning and port placement were similar to that used for robotic radical prostatectomy. Allograft cooling was achieved by ice slush delivered through a GelPOINT device. The accompanying video details the operative technique.

Outcome measurements and statistical analysis

The primary outcome was posttransplant graft function. Secondary outcomes included technical success or failure and complication rates.

Results and limitations

Fifty patients underwent RKT successfully, 7 in the phase 1 and 43 in the phase 2 stages of the study. For the initial 25 patients, mean console, warm ischemia, arterial, and venous anastomotic times were 135, 2.4, 12, and 13.4 min, respectively. All grafts were cooled to 18–20°C with no change in core body temperature. All grafts functioned immediately posttransplant and the mean serum creatinine level at discharge was 1.3 mg/dl (range: 0.8–3.1 mg/dl). No patient developed anastomotic leaks, wound complications, or wound infections. At 6-mo of follow-up, no patient had developed a lymphocele detected on CT scanning. Two patients underwent re-exploration, and one patient died of congestive heart failure (1.5 mo posttransplant).

Conclusions

RKT with regional hypothermia is safe and reproducible when performed by a team skilled in robotic surgery.

Patient summary

RKT is safe and effective when performed by surgeons experienced in robotic techniques.     

Increasing access to renal transplantation in India through our single‐center kidney paired donation program: a model for the developing world to prevent commercial transplantation

Because access to transplantation with HLA‐desensitization protocols and ABO incompatible transplantation is very limited due to high costs and increased risk of infections from more intense immunosuppression, kidney paired donation (KPD) promises hope to a growing number of end‐stage renal disease (ESRD) patient in India. We present a government and institutional ethical review board approved study of 56 ESRD patients [25 two‐way and 2 three‐way pairs] who consented to participate in KPD transplantation at our center in 2013, performed to avoid blood group incompatibility (n = 52) or positive cross‐match (n = 4). All patients had anatomic, functional, and immunologically comparable donors. The waiting time in KPD was short as compared to deceased donor transplantation. Laparoscopic donor nephrectomy was performed in 54 donors. Donor relationships were spousal (n = 40), parental (n = 13), others (n = 3), with median HLA match of 1. Graft survival was 97.5%. Three patients died with functioning graft. 16% had biopsy‐proven acute rejection. Mean serum creatinine was 1.2 mg/dl at 0.73 ± 0.32 months follow‐up. KPD is a viable, legal, and rapidly growing modality for facilitating LDRT for patients who are incompatible with their healthy, willing living donor. To our knowledge, this is the largest single‐center report from India.     

Correction: Realization of multi-configurable logic gate behaviour on fluorescence switching signalling of naphthalene diimide congeners

Correction for ‘Realization of multi-configurable logic gate behaviour on fluorescence switching signalling of naphthalene diimide congeners’ by Hridoy Jyoti Bora et al., RSC Adv., 2021, 11, 35274–35279. DOI: 10.1039/d1ra06728a.

The authors regret that there was an error in the sentence in lines 24–27 in the left column on page 35278 of the original article. The text originally read, “Mass spectrometric data Shimadzu UV-Vis spectrophotometer, UV-2600 is used to record the absorption spectra were gained from a THERMO 3000 Exactive Plus Orbitrap Mass Spectrometer”. This sentence should read, “Mass spectrometric data were gained from a THERMO 3000 Exactive Plus Orbitrap Mass Spectrometer. Shimadzu UV-Vis spectrophotometer, UV-2600 is used to record the absorption spectra”.The Royal Society of Chemistry apologises for these errors and any consequent inconvenience to authors and readers.     

Anesthesia protocol for ear surgery in Wistar rats (animal research)

ObjectiveTo formulate an anesthesia protocol for safe and satisfactory anesthesia for ear surgery in rats.MethodsThe rats were anesthetized with xylazine (10 mg/kg body weight) and ketamine at doses of 80, 50, 40, and 30 mg/kg body weight or with isoflurane anesthesia (2%–3.5% in 100% oxygen; maintenance dose 1.5%–3.5%). The anesthesia induction, surgery, and recovery time were recorded.ResultsIn total, 17 rats were induced by varying doses of ketamine‐xylazine and 28 rats with isoflurane. Mean induction time with ketamine‐xylazine was 6 ± 2.9 min compared with 3.8 ± 1.1 min with isoflurane. Mean recovery time with ketamine‐xylazine was 142.6 ± 49.3 min compared with 4.1 ± 1.2 min with isoflurane. A mortality of 4 animals after developing dyspnea was recorded with ketamine‐xylazine.ConclusionIsoflurane anesthesia offers appropriate induction and recovery times and low mortality rates for the surgeries performed. Isoflurane anesthesia offers reliable results for ear surgery in rats. However, more equipment and technical skills are needed.