Measurement of neonatal responses to painful stimuli: a research review

The measurement of neonatal responses to painful stimuli remains a significant clinical problem. Although numerous measures have been evaluated, instruments that are valid, reliable, and clinically feasible are not yet available. The purpose of this paper is to critique the studies that have been done using biochemical, physiological, and behavioral measures to evaluate neonatal responses to painful stimuli. Specific issues regarding measurement in premature and critically ill neonates are emphasized. The intent of this review and critique of the literature is to stimulate additional research into the assessment of neonatal pain.     

Bizarre imagery, interference, and distinctiveness.

Previous studies have shown that bizarre and common images produce equivalent levels of recall in unmixed-list designs. Using unmixed lists, we tested the view that bizarre images would be less susceptible than common images to common sources of interference. In all experiments, subjects imaged a list of either bizarre or common sentences and then performed some kind of interfering task before recalling the initial list of sentences. Experiment 1 showed that bizarre images were better accessed than common images after imaging an intervening list of common sentences. Also, components of common images tended to be better recalled than those of bizarre images after imaging an intervening list of bizarre sentences. Experiments 2a and 2b showed that interfering tasks consisting of studying lists of common concrete nouns did not differentially affect memory for bizarre and common images. In Experiment 3, labeling and imaging an interfering list of common pictures produced higher recall of bizarre images. Generally, bizarre images appeared to be less susceptible than common images to interference from certain types of common encodings. Importantly, the superior recall of bizarre images was always due to greater image (sentence) access, whereas higher recall of common images was associated with greater recovery of the image (sentence) constituents. Explanation of the precise pattern of results requires consideration of the distinctive properties of bizarre images. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ionoluminescence decay measured with single ions

A new ion beam analysis-based, single ion technique called the time to first photon has been developed to measure the decay of the luminescence signal of phosphors. Such measurements are currently needed to study luminescence decay mechanisms following high-density excitations and to identify strongly luminescent phosphor coatings with short lifetimes for ion photon emission microscopy (IPEM). The samples for this technique consist of thin phosphor layers placed or coated on the surface of PIN diodes. Single ions from an accelerator strike this sample and simultaneously create ion beam induced luminescence (IBIL) from the phosphor that is measured by a single-photon-detector, and an ion beam induced charge collection (IBICC) signal in the PIN diode. In this case, the IBICC signal provides the start pulse and the IBIL signal the stop pulse to a time to amplitude converter. It is straightforward to show that this approach also measures a signal proportional to activity versus time with an accuracy of 5% as long as the number of detected photons per ion is less than 0.1, which usually requires the use of absorbers for the IBIL detector or electronic discrimination for the IBIL signals. Details of the new analysis are given together with examples of luminescence decay measurements of several ceramic phosphors being considered to coat IPEM samples. IPEM is currently being developed at Sandia National Laboratory (SNL), the University of North Texas in Denton, and the Universities and INFN of Padova and Torino.     

Effects of size and orientation change on hippocampal activation during episodic recognition: a PET study

To determine whether physical match between studied and tested items influences blood flow increases in the hippocampal formation associated with recognition memory, positron emission tomography (PET) was used to measure changes in regional cerebral blood flow while healthy volunteers made old/new judgements about line drawings of objects. Some objects were tested in the same size and orientation as they had appeared earlier during the study phase of the experiment; other objects were tested in a different size or orientation than when they were studied. Blood flow increases in the vicinity of the hippocampal formation were observed in the same object condition compared with the size change and the orientation change conditions, even though recognition accuracy was affected significantly only by orientation change. Results add to previous findings suggesting that physical similarity between studied items and test cues may contribute to hippocampal activation during episodic retrieval.     

Scabies associated with a bullous pemphigoid-like eruption

Intramuscular phenol neurolysis is a well-known procedure used to decrease spasticity and improve function in patients who have failed to respond to more conservative forms of intervention. Traditionally, this approach has been limited to spasticity reduction in limb muscles, and its use in managing spasticity of the facial muscles has not been described in the literature. This case report describes a new and previously unreported application of intramuscular neurolysis for managing severe unrelenting facial muscle spasticity in a postanoxic encephalopathic patient. Prior to the procedure, hypertonicity in the orbicularis oris muscle was so profound that it limited speech and affected cosmetic, hygienic, and nutritional status. After intramuscular phenol neurolysis of the orbicularis oris muscle, the patient's level of functioning improved.     

Reduced dosage of genes encoding ribosomal protein S18 suppresses a mitochondrial initiation codon mutation in Saccharomyces cerevisiae

A yeast mitochondrial translation initiation codon mutation affecting the gene for cytochrome oxidase subunit III (COX3) was partially suppressed by a spontaneous nuclear mutation. The suppressor mutation also caused cold-sensitive fermentative growth on glucose medium. Suppression and cold sensitivity resulted from inactivation of the gene product of RPS18A, one of two unlinked genes that code the essential cytoplasmic small subunit ribosomal protein termed S18 in yeast. The two S18 genes differ only by 21 silent substitutions in their exons; both are interrupted by a single intron after the 15th codon. Yeast S18 is homologous to the human S11 (70% identical) and the Escherichia coli S17 (35% identical) ribosomal proteins. This highly conserved family of ribosomal proteins has been implicated in maintenance of translational accuracy and is essential for assembly of the small ribosomal subunit. Characterization of the original rps18a-1 missense mutant and rps18a delta and rps18b delta null mutants revealed that levels of suppression, cold sensitivity and paromomycin sensitivity all varied directly with a limitation of small ribosomal subunits. The rps18a-1 mutant was most affected, followed by rps18a delta then rps18b delta. Mitochondrial mutations that decreased COX3 expression without altering the initiation codon were not suppressed. This allele specificity implicates mitochondrial translation in the mechanism of suppression. We could not detect an epitope-tagged variant of S18 in mitochondria. Thus, it appears that suppression of the mitochondrial translation initiation defect is caused indirectly by reduced levels of cytoplasmic small ribosomal subunits, leading to changes in either cytoplasmic translational accuracy or the relative levels of cytoplasmic translation products.     

The incidence and characteristics of the clinical picture of recurrent myocardial infarct in the rural population

As many as 3033 patients with myocardial infarction residing in rural areas were kept under observation. In this population, myocardial reinfarction (MRI) was diagnosed in 411 subjects, with 78.8% having had it for 4 years. Those MRI patients ranging between 51 to 60 years showed the greatest prevalence (44.3%). The ratio of micro- to macrofocal (through-and-through) MRI was 1:3, that of males to females 9:1. Microfocal MRI was commonly associated with a pain-free variant of the disease (23.5%) with low frequency of thromboembolic complications (3.1%). Every fifth patient with macrofocal (through-and-through) renecrosis presented with aneurysm of the heart. In a 10-year and longer follow-up, mortality from MRI was 43.6 percent among patients with macrofocal MRI, while deaths attributable to microfocal MRI were estimated to be 28.9 percent. High mortality rates suggest great severity of illness and low efficacy of the drug therapy adopted.     

Reexpansion pulmonary edema

Reexpansion pulmonary edema is a rare complication attending the rapid reexpansion of a chronically collapsed lung, such as occurs after evacuation of a large amount of air or fluid from the pleural space. The condition usually appears unexpectedly and dramatically-immediately or within 1 h in 64% of patients and within 24 h in the remainder. The clinical manifestations are varied; they range from roentgenographic findings alone in asymptomatic patients to severe cardiorespiratory insufficiency. The radiographic evidence of reexpansion pulmonary edema is a unilateral alveolar filling pattern, seen within a few hours of reexpansion of the lung. The edema may progress for 24-48 h and persist for 4-5 days. Human data on the pathophysiology of reexpansion pulmonary edema derive from small series of patients, case reports, and reviews of the literature. On the other hand, a larger body of data exists on experimental reexpansion pulmonary edema in cats, monkeys, rabbits, sheep, and goats. This review examines the clinical and experimental evidence for reexpansion pulmonary edema. In addition, we detail the historical background, clinical setting, treatment, and outcome of reexpansion pulmonary edema.