NemoTrainer: Automated Conditioning for Stimulus-Directed Navigation and Decision Making in Free-Swimming Zebrafish

Current methods for associative conditioning in animals involve human intervention that is labor intensive, stressful to animals, and introduces experimenter bias in the data. Here, we describe a simple apparatus and a flexible, microcontroller-based conditioning paradigm that minimizes human intervention. Our methodology exploits directed movement towards a target that depends on spatial working memory, including processing of sensory inputs, motivational drive, and attentional mechanisms. Within a stimulus-driven conditioning paradigm designed to train zebrafish, we present a localized pulse of light via LEDs and/or sounds via an underwater transducer. A webcam placed below a glass tank records fish-swimming behavior. For classical conditioning, animals simply associate a sound or light with an unconditioned stimulus, such as a small food reward presented at a fixed location, and swim towards that location to obtain a few grains of food dispensed automatically via a sensor-triggered, stepper motor. During operant conditioning, a fish must first approach a proximity sensor at a remote location and then swim to the reward location. For both types of conditioning, a timing-gated interrupt activates stepper motors via custom software embedded within a microcontroller (Arduino). "Ardulink", a Java facility, implements Arduino-computer communication protocols. In this way, a Java-based user interface running on a host computer can provide full experimental control. Alternatively, a similar level of control is achieved via an Arduino script communicating with an event-driven application controller running on the host computer. Either approach can enable precise, multi-day scheduling of training, including timing, location, and intensity of stimulus parameters; and the feeder. Learning can be tracked by monitoring turning, location, response times, and directional swimming of individual fish. This facilitates the comparison of performance within and across a cohort of animals. Our scheduling and control software and apparatus ("NemoTrainer") can be used to study multiple aspects of species-specific behaviors as well as the effects on them of various interventions.

447 Evaluation of JPI System as Prognostic Tool in Cases of Perforation Peritonitis

Aim

Perforation peritonitis is a commonly encountered condition in surgical practice in any hospital. One of the reasons for high mortality in these conditions is lack of risk stratification resulting in delay in providing adequate management, although a number of scoring systems are available to stratify these patients according to severity, but most of these cannot be used in developing countries like India due to their dependency on sophisticated investigation which are usually lacking in most parts of these countries. This study aims to evaluate a simple scoring system for peritonitis.

Method

Fifty cases with diagnosis of peritonitis coming to Government Medical College, Amritsar were stratified according to Jabalpur peritonitis Index and their outcome was examined.

Results

Mortality steadily increases with increase in JPI score. Patients with JPI score of < 9 and >9 had mortality rate of 2.5% and 60% respectively)(p < 0.01) and similarly morbidity of 30% and 80% (p < 0.0001).Duration of pain >24 hours, age >50 years, mean SBP <100 mmHg, serum creatinine >1.5 mg/dl, respiratory rate >24/min, heart rate >110/min and feculent exudate intra operatively were found to be independently significant factors in predicting the mortality among the study population. For a score of 9, the sensitivity was 85.7%, specificity was 90.7% and positive predictive value for mortality is 40% and negative predictive value of 97.5%.

Conclusions

This study proves that JPI scoring system is a simple and effective tool for assessing the morbidity and mortality in patients with peritonitis.

A comparative study of different graft materials used in myringoplasty

Two hundred twenty cases of unilateral chronic suppurative otitis media (CSOM) with dry central perforation were chosen for this study and myringoplasty were done. Age group ranged from 13 to 48 years. Four types of autogenous tissues were used as graft material. Grafting was done by underlay technique when temporalis fascia, tragal perichondrium, areolar tissue were used as graft material and when fat graft was used the ear lobule fat was placed directly into perforation through transcanal route. Postoperative follow-up was carried out up to 6 months. In this study, it was found that the younger age group has less impairment of hearing and better chance of tympanic membrane perforation closure than the older age group in CSOM with central perforation. Anterior perforations has less impairment of hearing and better result in successful closure of tympanic membrane than posterior perforation group. It was also observed that larger the size of perforation greater is the hearing impairment preoperatively and postoperative hearing gain is also less compared to small perforation. Best hearing improvement occurred using temporalis fascia. Failure occurred may be due to postoperative infection, respiratory tract infection, neglected post-operative advice etc.

An unfavourable outcome after periprosthetic fracture following metal-on-metal surface hip arthroplasty

We report a case of a varus malunited periprosthetic femoral neck fracture following metal-on-metal hip resurfacing operation. Failure to closely observe and poor compliance in the young and active group of patients may contribute to such an unfavourable outcome.

Metal-on-metal surface hip arthroplasty in patients with abnormal Coxanatomy: preliminary results

The purpose of this study was to evaluate early to intermediate results of metal-on-metal (MoM) hip resurfacing arthroplasty in patients with abnormal hip anatomy. We evaluated nine MoM hip resurfacing arthroplasty in eight patients with abnormal coxanatomy performed at a district general hospital in the UK between March 1999 and November 2002. One patient had undergone bilateral sequential hip resurfacing procedure. These patients were defined to have abnormal coxanatomy by virtue of previous dysplastic disease of hip in three cases, previous Legg-Calve-Perthes disease, multiple epiphyseal dysplasia, T cell acute lymphoblastic leukaemia, trauma and sepsis in one case each. The mean follow-up was 40.8 months. The mean age at primary operation was 35 years (range: minimum 21 years; maximum 44 years). There were six male and two female patients. There were six right-sided and three left-sided procedures. All patients had satisfactory outcomes. There were no deep infections, dislocations, or femoral neck fractures. Although this is a short series, MoM resurfaced hips with appropriate case selection can yield satisfactory short-term to intermediate-term results in the young and active patients with abnormal hip anatomy.

Femoral neck fractures complicating metal-on-metal resurfaced hips: a report of 2 cases

Metal-on-metal hip resurfacing arthroplasty is increasingly popular for younger patients with advanced hip disease. Intra-operative or immediate postoperative femoral neck fracture after metal-on-metal hip resurfacing is a well-described technical complication, ranging from 0% to 1.5%. We report 2 cases of late femoral neck fracture occurring 8 and 15 months following the index operation, with a review of the literature. We recommend that patient selection should be of prime importance before embarking on metal-on-metal surface hip replacement to avoid such complications.

Delayed management of fracture of the lateral humeral condyle in children

Thirty-nine displaced fractures of the lateral humeral condyle in children were followed for an average of 5 (2-5) years. The results were evaluated from functional and cosmetic aspects. Patients treated within 2 weeks by open reduction and internal fixation did well. Those operated on after 6 weeks did not do better than nonoperated on cases. Complications included cubitus varus and valgus deformities, osteonecrosis, nonunion and malunion, and loss of motion. We recommend that patients presenting late be left alone and any sequelae evaluated at a late stage.