Extrinsic cues suppress the encoding of intrinsic cues

Remembering where objects are in space is fundamental to adaptive behavior. Little is known about how intact humans combine information from intrinsic (egocentric) and extrinsic (exocentric, allocentric, or landmark-based) coordinate systems to locate objects. Using a simple location estimation paradigm, this study finds that we mostly remember position in extrinsic coordinates. Intrinsic-coordinate-based mapping of space is less precise in the presence of landmarks or extrinsic cues than in their absence. Thus, not only do extrinsic frames of reference dominate internal representations of space, they suppress intrinsic-based representations as well. We speculate that this dominance-suppression hierarchy undercuts intersystem conflicts and underlies a single, undissociated spatial map in intact humans.     

Dynamical evolution of motion perception

Motion is defined as a sequence of positional changes over time. However, in perception, spatial position and motion dynamically interact with each other. This reciprocal interaction suggests that the perception of a moving object itself may dynamically evolve following the onset of motion. Here, we show evidence that the percept of a moving object systematically changes over time. In experiments, we introduced a transient gap in the motion sequence or a brief change in some feature (e.g., color or shape) of an otherwise smoothly moving target stimulus. Observers were highly sensitive to the gap or transient change if it occurred soon after motion onset (< or =200 ms), but significantly less so if it occurred later (> or = 300 ms). Our findings suggest that the moving stimulus is initially perceived as a time series of discrete potentially isolatable frames; later failures to perceive change suggests that over time, the stimulus begins to be perceived as a single, indivisible gestalt integrated over space as well as time, which could well be the signature of an emergent stable motion percept.     

Bone Conduction Improvement After Surgery for Conductive Hearing Loss

The objective is to evaluate change in post-operative bone conduction in patients who underwent surgery for conductive/mixed hearing loss due to various reasons. The study design is of retrospective case review and tertiary referral center setting. Five-hundred patients with unilateral conductive/mixed hearing loss were divided into five equal groups (each representing different causes for pre-operative hearing loss), who underwent appropriate surgical correction and had a follow-up audiogram available. The intervention comprises surgery (like myringoplasty and ossiculoplasty with closed or open cavity mastoidectomy for chronic otitis media, stapes mobilization for tympanosclerosis and stapedotomy for otosclerosis) for conductive/mixed hearing loss. Significant improvement or worsening in bone conduction was defined as 15 dB or more improvement or worsening of bone conduction threshold at least in two frequencies between 500 and 4000 Hz. All the other groups also showed a consistent pre-operative bone conduction reduction with an equally consistent improvement in post-operative bone conduction improvement to a varying degree with otosclerosis group having maximum percentage of patients with post-operative bone conduction improvement (60%). The measurement of bone conduction is not necessarily a true reflection of the function of the inner ear. Middle ear makes a contribution to bone conduction and correction of a middle ear conductive lesion causes an apparent improvement in inner ear function. The apparent inner ear hearing loss caused in this way may be reversible to some extent.     

Single-incision laparoscopic percutaneous hydatid cystectomy: a novel curative approach for segment 7 hydatid cyst of liver

Hydatid disease of the liver is one of the common cystic disease of the liver. Chemotherapy as well operative procedures are generally opted for the treatment of hydatid disease of the liver. Apart from open surgical intervention, (PAIR) Percutaneous Aspiration Injection & reaspiration, Laparoscopic hydatid cystectomy is also popularized. We have developed a novel technique for segment 7 liver hydatid cyst as a combination of single incision percutaneous technique with direct visualisation of cystic cavity under sonographic guidance.     

Efficacy and safety of deferasirox for reducing total body and cardiac iron in Thalassemia

Objective  

To assess the efficacy of deferasirox as an iron chelator, with specific reference to reducing cardiac iron overload.     

Analysis of a second-generation tetracycline antibiotic minocycline in human plasma by LC-MS/MS

A simple, selective and sensitive LC-MS/MS assay has been developed for the determination of minocycline in human plasma. Plasma samples were prepared by protein precipitation, followed by chromatographic separation on a HyPURITY? C8 (100 mm × 4.6 mm, 5 μm) column under isocratic conditions. The LOD and LLOQ of the method were 0.50 and 20.0 ng/ml, respectively. The intra-batch and inter-batch precision (% coefficient of variation) across quality control levels was less than 8.0%. For a set of incurred samples the percentage change in concentration was within ± 9.0%. The method was successfully applied to a bioequivalence study of 135 mg minocycline tablet formulation in 14 healthy Indian males. The reproducibility in the measurement of study data was demonstrated by incurred sample reanalysis.     

Effect of Deferasirox Chelation on Liver Iron and Total Body Iron Concentration

Objective

To determine efficacy of Deferasirox (DFX) on total body iron and liver iron concentration (LIC) as estimated by serum ferritin (SF) and liver MRI T2*.

Methods

Thirty patients had baseline MRI T2* of the liver performed to determine LIC before starting DFX therapy and classified as normal >6.3 milliseconds (ms), mild 6.3?2.7 ms, moderate 2.7?1.4 ms and severe iron overload <1.4 ms. DFX was given 25–35 mg/kg/d. The serum ferritin (SF) level was estimated every 3 monthly. Liver iron is expressed as liver R2*?=?1000/T2*. The primary end point of the study was to determine change in SF and liver MRI R2* values after 18 mo of therapy.

Results

All 30 patients had some degree of liver iron overload; 11 (36.6 %) had severe, 15 (50 %) had moderate while 4 (13.3 %) had mild overload. The pre-DFX therapy median SF of all was 3604.5 ng/mL (IQR 2357.0–5056.0) and median liver R2* was 574.71 Hz (IQR 411.3–770.8). After 18 mo, SF dropped significantly to a median of 2036.5 ng/mL (IQR 1700.0–3162.0) (p?=?0.0011), while median liver R2* decreased from 574.71 to 568.18Hz (IQR 393.4–803.2) which was not significant (p?=?0.986).

Conclusions

DFX monotherapy at the doses used decreases total body iron, but does not significantly decrease liver iron. It is well tolerated by Indian thalassemia patients, with observed side effects including rash, diarrhea, and transient albuminuria. MRI T2* (and derived R2*) can serve as useful method in non invasive monitoring of LIC in thalassemia patient management.     

Office management of the patient with chronic cough

Chronic cough is a common complaint in the ambulatory setting and can result in significant compromise in quality of life and, uncommonly, is a presenting symptom of serious or life-threatening disease. Although there are many potential causes, an organized approach to diagnosis that may include therapeutic trials of select medications can establish the diagnosis in over 90% of presenting patients. Management hinges on accurate etiologic diagnosis. Consultation with a pulmonologist, otolaryngologist, or allergist is indicated in selected cases where diagnosis is unclear or specific therapy is mandated.     

National trends in discharge disposition after hepatic resection for malignancy

Background

There is a paucity of data on the trends in discharge disposition for patients undergoing hepatic resection for malignancy.

Aim

To analyse the national trends in discharge disposition after hepatic resection for malignancy.

Methods

The National Inpatient Sample (NIS) database was queried (1993 to 2005) to identify patients that underwent hepatic resection for malignancy and analyse the discharge status (home, home health or rehabilitation/skilled facility).

Results

A weighted total of 74 520 patients underwent hepatic resection of whom, 53 770 patients had a principal diagnosis of malignancy. The overall mortality improved from 6.3% to 3.4%. After excluding patients that died in the post-operative period and those with incomplete discharge status, 45 583 patients were included. The proportion of patients that had acute care needs preventing them from being discharged home without assistance increased from 10.9% in 1993 to 19.5% in 2005. While there was an increase in the number of patients discharged to home health care during this time (8.9% to 13.8%), there was a larger increase in the proportion of patients that were discharged to a rehabilitation or skilled nursing facility (2% to 5.7%). Despite a decrease in the mortality rates, there was no improvement in rate of patients discharged home without assistance over the period of the study.

Conclusions

The results of the present study demonstrate that after hepatic resection, a significant proportion of patients will need assistance upon discharge. This information needs to be included in patient counselling during pre-operative risk and benefit assessment.