Infrapopliteal drug-eluting stents for chronic limb ischemia.

OBJECTIVE: We report our experience with the elective placement of below-knee, drug-eluting stents in patients with chronic limb ischemia. BACKGROUND: Infrapopliteal percutaneous transluminal angioplasty has been associated with a lower rate of procedural success and high rate of restenosis because of the small size of the tibial vessels and the prevalence of calcified and diffuse atherosclerotic disease. Prior published data reports 3-year patency rates below 25%. Bare metal stents have been reported in bailout situations. Drug-eluting stents have markedly reduced restenosis compared to bare metal stents in the coronary vasculature, but there is little data supporting the use of these devices below the knee. METHODS: Elective placement of drug-eluting stents in infrapopliteal lesions was performed on 10 patients with severe (> or =Fontaine Stage IIb) claudication (n = 1) or limb-threatening ischemia (n = 9) (rest pain, nonhealing ulcers and gangrene). RESULTS: A total of 17 drug-eluting stents were electively placed in 12 below-knee arteries in 10 patients, resulting in an average of 1.7 +/- 0.7 stents per patient. The mean lesion length was 24.8 +/- 10.9 mm, the mean total stent length was 38.3 +/- 19.1 mm, and the mean nominal stent diameter was 2.8 +/- 0.3 mm. One patient required target vessel revascularization (TVR) at 3 weeks because of stent thrombosis. TVR was 10% at 12.4 +/- 6.5 months of follow-up. Clinically driven angiography in three different patients was performed at 4, 15, and 16 months and confirmed drug-eluting stent patency in each case. CONCLUSIONS: The use of below-knee drug-eluting stents is feasible and appears to be safe in our small series of complex infrapopliteal lesions causing chronic limb ischemia. The occurrence of a single case of stent thrombosis warrants continued observation in this cohort. Prospective clinical trials will be necessary to confirm the benefits and justify the costs of this strategy for treating patients with infrapopliteal culprit lesions and chronic limb ischemia.

Catheter-based treatment of the subclavian and innominate arteries.

OBJECTIVES: We report outcomes in patients undergoing catheter-based intervention for symptomatic subclavian and innominate artery (S/IA) atherosclerosis. BACKGROUND: Symptomatic S/IA obstructive lesions have traditionally been treated with open surgical revascularization. Catheter-based endovascular therapies reduce the morbidity and mortality associated with surgery in many vascular beds. METHODS: Between December 1993 and May 2006, 170 patients underwent primary stent placement in 177 S/IA arteries. Indications for revascularization included arm ischemia (57%), subclavian steal syndrome (37%), coronary-subclavian steal syndrome (21%), and planned coronary bypass surgery with the involved internal mammary artery (8%). RESULTS: Technical success was achieved in 98.3% (174/177) arteries, including 99.4% for stenotic lesions (155/156) and 90.5% for occlusions (19/21). There were no procedure-related deaths and one stroke (0.6%, 1/170). Follow-up was obtained in 151 (89%) patients at 35.2 +/- 30.8 months, with a target vessel revascularization rate of 14.6% (23/157). At last follow-up, 82% (124/151) of all treated patients remained asymptomatic with a primary patency of 83% and a secondary patency of 96%. CONCLUSIONS: Catheter-based revascularization with stents for symptomatic S/IA lesions is safe and effective with excellent patency rates and sustained symptom resolution in the majority (>80%) of patients over 3 years of follow-up. Percutaneous primary stent therapy is the preferred method of revascularization in patients with suitable anatomy.

The yeast heat shock transcription factor changes conformation in response to superoxide and temperature.

In vitro DNA-binding assays demonstrate that the heat shock transcription factor (HSF) from the yeast Saccharomyces cerevisiae can adopt an altered conformation when stressed. This conformation, reflected in a change in electrophoretic mobility, requires that two HSF trimers be bound to DNA. Single trimers do not show this change, which appears to represent an alteration in the cooperative interactions between trimers. HSF isolated from stressed cells displays a higher propensity to adopt this altered conformation. Purified HSF can be stimulated in vitro to undergo the conformational change by elevating the temperature or by exposing HSF to superoxide anion. Mutational analysis maps a region critical for this conformational change to the flexible loop between the minimal DNA-binding domain and the flexible linker that joins the DNA-binding domain to the trimerization domain. The significance of these findings is discussed in the context of the induction of the heat shock response by ischemic stroke, hypoxia, and recovery from anoxia, all known to stimulate the production of superoxide.

Measurement and simulation of unmyelinated nerve electrostimulation: Lumbricus terrestris experiment and numerical model.

The electrostimulation excitation threshold of a nerve depends on temporal and frequency parameters of the stimulus. These dependences were investigated in terms of: (1) strength-duration (SD) curve for a single monophasic rectangular pulse, and (2) frequency dependence of the excitation threshold for a continuous sinusoidal current. Experiments were performed on the single-axon measurement setup based on Lumbricus terrestris having unmyelinated nerve fibers. The simulations were performed using the well-established SENN model for a myelinated nerve. Although the unmyelinated experimental model differs from the myelinated simulation model, both refer to a single axon. Thus we hypothesized that the dependence on temporal and frequency parameters should be very similar. The comparison was made possible by normalizing each set of results to the SD time constant and the rheobase current of each model, yielding the curves that show the temporal and frequency dependencies regardless of the model differences. The results reasonably agree, suggesting that this experimental setup and method of comparison with SENN model can be used for further studies of waveform effect on nerve excitability, including unmyelinated neurons.

Contrast echocardiography clarifies uninterpretable wall motion in intensive care unit patients.

OBJECTIVES: The study examined the value of contrast echocardiography in the assessment of left ventricular (LV) wall motion in intensive care unit (ICU) patients. BACKGROUND: Echocardiograms done in the ICU are often suboptimal. The most common indication is the evaluation of LV wall motion and ejection fraction (EF). METHODS: Transthoracic echocardiograms were done in 70 unselected ICU patients. Wall motion was evaluated on standard echocardiography (SE), harmonic echocardiography (HE), and after intravenous (IV) contrast echocardiography (CE) using a score for each of 16 segments. A confidence score was also given for each segment with each technique (unable to judge; not sure; sure). The EF was estimated visually for each technique, and a confidence score was applied to the EF. RESULTS: Uninterpretable wall motion was present in 5.4 segments/patient on SE, 4.4 on HE (p = 0.2), and 1.1 on CE (p < 0.0001). An average of 7.8 segments were read with surety on SE, 9.2 on HE (p = 0.1), and 13.7 on CE (p < 0.0001). Ejection fraction was uninterpretable in 23% on SE, 13% on HE (p = 0.14), and 0% on CE (p = 0.002 vs. HE; p < 0.0001 vs. SE). The EF was read with surety in 56% of patients on SE, 62% on HE (p = 0.47), and 91% on CE (p < 0.0001). Thus, wall motion was seen with more confidence on CE. More importantly, the actual readings of segmental wall motion and EF significantly differed using CE. CONCLUSIONS: CE should be used in all ICU patients with suboptimal transthoracic echocardiograms.

Elucidation of the initial step of oligonucleotide fragmentation in matrix-assisted laser desorption/ionization using modified nucleic acids.

To probe the mechanism of gas-phase oligonucleotide ion fragmentation, modified oligonucleotides were studied using matrix-assisted laser desorption/ionization. The oligonucleotides were of the form 5'-TTTTXTTTTT, where X was a modified nucleotide. Modifications included substitution of hydroxy, methoxy, amino, and allyl groups at the 2'-position of the deoxyribose. The modified ribose contained adenine, guanine, cytosine, or uracil bases. For comparison, we studied oligomers where X was an unmodified adenosine, guanosine, cytidine, thymidine, or uridine deoxyribonucleotide. We found a very strong dependence of the matrix-to-analyte ratio on fragmentation for these oligomers. Analysis of these modifications suggests that the initial fragmentation step in MALDI-MS involves a two-step (E1) elimination of the base.

Gas-phase separations of protease digests.

A mixture of peptides from a complete tryptic digest of ubiquitin has been analyzed by ion mobility/time-of-flight mass spectrometry techniques. All components of the mixture were electrosprayed and ions were separated in the gas phase based on differences in their mobilities through helium before being dispersed into a time-of-flight mass spectrometer for mass-to-charge analysis. The data show that ions separate into families primarily according to differences in their charge states and, to a lesser extent, differences in conformation. This approach reduces spectral congestion typically associated with electrosprayed mixtures and provides charge assignments for mass-to-charge ratio data. Gas-phase separations of ions appear to provide a new physical basis for characterizing components of biological mixtures.

Increased neuronal excitability after long-term O(2) deprivation is mediated mainly by sodium channels.

We have previously observed that prolonged O(2) deprivation alters membrane protein expression and membrane properties in the central nervous system. In this work, we studied the effect of prolonged O(2) deprivation on the electrical activity of rat cortical and hippocampal neurons during postnatal development and its relationship to Na(+) channels. Rats were raised in low O(2) environment (inspired O(2) concentration = 9.5+/-0.5%) for 3-4 weeks, starting at an early age (2-3 days old). Using electrophysiologic recordings in brain slices, RNA analysis (northern and slot blots) and saxitoxin (a specific ligand for Na(+) channels) binding autoradiography, we addressed two questions: (1) does long-term O(2) deprivation alter neuronal excitability in the neocortical and hippocampal neurons during postnatal development? and (2) if so, what are the main mechanisms responsible for the change in excitability in the exposed brain? Our results show that (i) baseline membrane properties of cortical and hippocampal CA1 neurons from rats chronically exposed to hypoxia were not substantially different from those of naive neurons; (ii) acute stress (e.g., hypoxia) elicited a markedly exaggerated response in the exposed neurons as compared to naive ones; (iii) chronic hypoxia tended to increase Na(+) channel mRNA and saxitoxin binding density in the cortex and hippocampus as compared to control ones; and (iv) the enhanced neuronal response to acute hypoxia in the exposed cortical and CA1 neurons was considerably attenuated by applying tetrodotoxin, a voltage-sensitive Na(+) channel blocker, in a dose-dependent manner. We conclude that prolonged O(2) deprivation can lead to major electrophysiological disturbances, especially when exposed neurons are stressed acutely, which renders the chronically exposed neurons more vulnerable to subsequent micro-environmental stress. We suggest that this Na(+) channel-related over-excitability is likely to constitute a molecular mechanism for some neurological sequelae, such as epilepsy, resulting from perinatal hypoxic encephalopathy.

Chronic hypoxia in vivo renders neocortical neurons more vulnerable to subsequent acute hypoxic stress.

We studied the neurophysiology of neurons from the central nervous system (CNS) of rats that were exposed to a long-term (3-4 weeks) low oxygen (FiO2 = 9.5 +/- 0.5%) environment (exposed). Age-matched normoxic animals served as controls (naive). We measured membrane potential (Vm) and input resistance (Rm) at rest and in response to two levels (20% and 0% O2) of acute in vitro hypoxia using intracellular recordings in the brain slice from two areas of the CNS, layer 2/3 of the neocortex (NCX) and the hypoglossal nucleus in the brainstem (XII). Resting Vm and Rm were not different between exposed and naive neurons. However, acute hypoxia elicited dramatic differences between exposed and naive NCX neurons. Exposed NCX depolarized 5 x more (delta Vm = 53.2 +/- 7.0 mV; n = 13; mean +/- S.E.M.) than naive NCX (delta Vm = 10.6 +/- 2.0; n = 8) in response to 20% O2. In 0% O2, naive NCX showed anoxic depolarization (delta Vm > 20 mV/min) much sooner (mean latency of 4.8 +/- 0.4 min; n = 18) than naive NCX (8.8 +/- 1.0 min; n = 19). Rm decreased 2-4 times more in exposed NCX compared to naive NCX in response to O2 deprivation. In addition, while all naive NCX recovered to baseline Vm and Rm when re-oxygenated, exposed NCX exhibited a much slower recovery compared to naive NCX, and almost 20% of the exposed NCX failed to recover Vm and Rm following in vitro hypoxia. In contrast to NCX, there was little difference between exposed XII and naive XII. We conclude that chronic hypoxia renders neurons in the neocortex more vulnerable to subsequent acute stress such as O2 deprivation.

Major differences in response to graded hypoxia between hypoglossal and neocortical neurons.

Intracellular electrophysiologic recordings were performed in brain slices from adult rats to compare the response of brain stem hypoglossal neurons (XII) and layer II/III neocortical neurons (NCX) to two levels of oxygen deprivation (hypoxia, pO2 = 15-20 Torr; anoxia, pO2 = 0 Torr). These recordings were also used during re-oxygenation after hypoxia or anoxia to study neuronal recovery. Both groups of neurons showed a greater response to anoxia than hypoxia in terms of membrane potential (Vm) and input resistance (Rm). When the two groups were compared at each level of O2, XII depolarized more and in a shorter period of time than NCX. During anoxia, XII neurons responded with anoxic depolarization (AD) of > 20 mV/min by 3 min, along with a large decrease in Rm. NCX neurons, on the other hand, exhibited AD after a mean latency of approximately 9 min and 18% of NCX neurons did not even show AD. Although all neurons (both XII and NCX) recovered when re-oxygenated before or at AD, XII neurons failed to recover from periods of anoxia that were well tolerated by NCX neurons. We conclude that: (1) there are marked differences in the magnitude and trajectory of membrane depolarization between XII and NCX neurons in response to O2 deprivation, with NCX neurons showing a much longer latency to AD during anoxia than XII; and (2), when exposed to periods of anoxia of similar duration and severity, XII neurons are less likely to recover than NCX neurons and XII neurons may, therefore, be inherently more vulnerable to anoxia-induced injury than NCX neurons.

Comparative effects of UV A and UV B on clonogenic survival and delayed cell death in skin cell lines from humans and fish.

The effects of UV radiation on humans and animals are receiving increasing attention and much interest has recently been focused on the environmental effects of UV A and UV B. This study compares the in vitro effects of UV A and UV B on the clonogenic survival of two human skin keratinocyte cell lines, HaCaT which are immortal but not tumorigenic and HPV-G transfected keratinocytes which form non malignant tumours in nude mice. The effects were also studied on an EPC fish cell line. The aim of the work was to establish if similar initial and delayed survival responses occurred in both species. The cells were exposed to ultraviolet lamps emitting maximally at 365 nm (UV A) and 302 nm (UV B). Clonogenic survival was determined at appropriate times post exposure. Results for the initial survival curves show that the HaCaT and HPV-G cells did not show any appreciable difference in their response to UV A but the EPC cells were more sensitive at doses < 3000 Jm-2. The EPC cells were more sensitive to UV B at doses < 200 Jm-2 in comparison to the human HaCaT and HPV-G cells with the HPV-G cells showing the most sensitivity to UV B at doses > 200 Jm-2. The possible contribution of lethal mutations (delayed cell death) to the UV radiation response in the HaCaT and EPC cell lines was examined. The results showed that lethal mutations were expressed in the HaCaT cells following exposure to UV A and UV B but no lethal mutations were expressed in the EPC cells.

Disorders of the sacro-iliac joint in children.

The cases of seventeen children whose ages ranged from two to eighteen years and who were treated for a disorder of a sacro-iliac joint between 1975 and 1983 were reviewed retrospectively. Thirteen children were acutely ill, with a temperature of more than 38 degrees Celsius, and four had chronic symptoms that had persisted for three weeks to one year. Pain in the hip, thigh, and buttock was the most common symptom. Of the thirteen acutely ill patients, eleven had septic arthritis of a sacro-iliac joint, while one who had ankylosing spondylitis and one who had juvenile rheumatoid arthritis had acutely painful arthritis of a sacro-iliac joint. Of the four patients who had chronic symptoms, two had septic arthritis of a sacro-iliac joint; one, ankylosing spondylitis with sacro-iliac involvement; and one, eosinophilic granuloma of the ilium. Thus, thirteen patients had septic arthritis of a sacro-iliac joint and four had some other disorder. For the seventeen children who had acute or chronic symptoms, at admission the white blood-cell count ranged from 3,500 to 26,200 per cubic millimeter (average, 11,100 per cubic millimeter) and the sedimentation rate, as determined by the Westergren technique, ranged from twenty-two to sixty-five millimeters per hour (average, fifty millimeters per hour). Twelve of the plain radiographs of the seventeen patients were negative. The initial bone scans of all seventeen patients were positive in eleven and negative in six. Of these six, five had septic arthritis and one, juvenile rheumatoid arthritis. A computed tomographic scan was performed in four patients and was positive in all of them: three had septic arthritis and one had ankylosing spondylitis. Organisms were cultured successfully from blood, from material aspirated from the sacro-iliac joint, or from stool of all thirteen patients who had sepsis. The thirteen infections responded well to appropriate antibiotics, which were administered intravenously to seven patients and first intravenously and then orally to six.

Intramedullary nailing of femoral shaft fractures. Part I: Decision-making errors with interlocking fixation.

Dynamic intramedullary fixation depends on the configuration of the fracture for postoperative stability. Unanticipated loss of reduction of the fracture after dynamic intramedullary nailing of the femur may result from errors in surgical decision-making, specifically the failure to insert both proximal and distal interlocking screws. Of 133 dynamic femoral intramedullary nailings that were performed after interlocking techniques became routinely available, fourteen (10.5 per cent) were complicated by loss of postoperative fixation and reduction. Thirteen of the fourteen femora shortened an average of 2.0 centimeters; the remaining femur shortened slightly, with clinical loss of rotational stability. Eight of fourteen patients elected some form of surgical revision, most commonly closed osteoclasis with restoration of femoral length, followed by the insertion of a statically locked nail. Errors in surgical judgment were attributed to inadequate preoperative analysis of the pattern of the fracture; undetected intraoperative comminution during reaming or insertion of the nail, or both; or postoperative failure to recognize an increase in comminution and instability of the fracture. We suggest using high-quality preoperative radiographs to detect non-displaced comminution of the major fracture fragments. Any increase in comminution of the fracture that occurs with reaming of the canal or insertion of the nail is an indication for static interlocking fixation. Radiographs that are made immediately postoperatively should be analyzed while the patient is under anesthesia, and any previously undetected instability of the fracture should be treated by static interlocking fixation. Dynamic intramedullary stabilization of the femur should be reserved for transverse or short oblique fractures at the femoral isthmus that have type-I or type-II comminution.

Theoretical evaluation of peripheral nerve stimulation during MRI with an implanted spinal fusion stimulator.

This study examines the requirements for nerve excitation near a spinal fusion implant during magnetic resonance imaging. The implant is the Spinal Fusion SpF device manufactured by Electro Biology Inc. The electric field induced within the biological medium was calculated using a three-dimensional finite difference model (described in a separate paper by Beuchler et al. from the University of Utah). Magnetic thresholds were obtained for excitation of myelinated nerve fibers that are near the implant. Minimum (rheobase) thresholds were determined for long duration dB/dt pulses, as well as strength-duration time constants (from which thresholds at other durations could be determined) for various geometries between the implant and a myelinated nerve fiber. The lowest thresholds occur when a large (20-microm diameter) fiber is situated near the bare tip of a wire from the implant, and a long duration (2 ms) stimulus is provided for which dB/dt is constant and monophasic. Magnetic thresholds for shorter durations of dB/dt are higher in accordance with a strength-duration law. In a magnetic field having a time derivative of 10 T/s that is uniform over the torso, nerve excitation is possible under worst-case conditions only for nerve fibers that are within 0.14 mm of the bare wire tip of the implant. With 20 T/s, excitation is possible only within 1 mm of the wire tip.

Maximum pulsed electromagnetic field limits based on peripheral nerve stimulation: application to IEEE/ANSI C95.1 electromagnetic field standards.

This communication proposes a rationale for maximum pulsed magnetic field limits in the electromagnetic-field standards of IEEE/ANSI C95.1. The peak limits, intended to protect against peripheral nerve excitation by pulsed fields, are adapted from existing standards for patient exposure in magnetic resonance imaging (MRI) examinations.

The prediction of chronicity in patients with an acute attack of low back pain in a general practice setting.

STUDY DESIGN: Three hundred patients, attending their general practitioners with attacks of acute low back pain, formed the subject population for a study of fear avoidance and other variables in the prediction of chronicity. Follow-up was at 2 and 12 months. OBJECTIVE: The hypothesis to be tested was that evidence of psychological morbidity, particularly fear-avoidance behavior, would be manifest from the outset of the presenting attack in susceptible subjects. SUMMARY OF BACKGROUND DATA: While back pain is an almost universal human experience, only about 5% of sufferers seek medical advice. Most of these respond to conservative treatment. However, approximately 10% of those who experience an acute attack of low back pain go on to become chronic sufferers. METHODS: Psychosocial and physiological data (including fear-avoidance measures) were collected from a sample of 300 acute low back pain patients within 1 week of presentation and at 2 months, to try to predict 12 month outcome. RESULTS: Data analysis showed that subjects who had not recovered by 2 months were those who went on to become chronic low back pain patients (7.3%). Using multiple regression analyses, fear-avoidance variables were the most successful in predicting outcome. Using multiple discriminant function analyses, the results suggest that the outcome in terms of the future course of low back pain can be correctly classified in 66% from fear-avoidance variables alone and in 88% of patients from all variables. CONCLUSIONS: The results suggest that, at the earliest stage of low back pain, fear of pain should be identified by clinicians and, where this is severe, pain confrontation should arguably form part of the approach to treatment.

Chronic low back pain rehabilitation programs: a study of the optimum duration of treatment and a comparison of group and individual therapy.

STUDY DESIGN: Eighty-four patients with chronic low back pain were treated using cognitive behavioral principles on a pain management program. Outcome data were collected at four points: 10 weeks before treatment, immediately before and immediately after treatment, and 6 months after treatment. In part 1 of the study, patients were assigned randomly to group or individual treatment contexts. In part 2 of the study, patients were assigned randomly to programs of 15, 30, or 60 hours duration. OBJECTIVES: To identify the differences in outcome between programs that treated patients as part of a group and those that treated patients individually and the effects of duration of treatment on outcome. SUMMARY OF BACKGROUND DATA: Cognitive behavioral programs have been shown to be an effective means of managing chronic low back pain. The literature is concerned with group programs, however, the duration of which vary widely. METHOD: Psychological and functional variables were measured before and after treatment and at the 6-month follow-up visit. Changes in these variables were measured, and comparisons were made between group and individual programs and between 15-, 30-, and 60-hour programs. RESULTS: Data analysis showed a significant, beneficial effect of intervention in terms of the majority of variables; however, these changes were generally independent of whether patients were treated as part of a group or individually and whether patients completed a 15-, 30-, or 60-hour program. CONCLUSIONS: Cognitive behavioral rehabilitation programs have been demonstrated to be an effective means of reducing psychological distress, of changing cognition, and of improving the function of patients with chronic low back pain; however, the length of program and whether patients were treated individually or as part of a group did not affect outcome. This finding has clinical and economic implications.

Safety profile of the proton-pump inhibitors.

The adverse effect profile of proton-pump inhibitors is presented. The proton-pump inhibitors are a well-tolerated class of drugs. The most common adverse events of headache, diarrhea, and nausea have been reported in fewer than 5% of patients treated with lansoprazole or omeprazole. The frequency of these adverse events with the two proton-pump inhibitors is comparable to that of placebo and histamine H2-receptor antagonists. Few clinically important interactions have been observed between proton-pump inhibitors and other drugs metabolized by the cytochrome P-450 system. The interaction potential should be considered when drugs with a narrow therapeutic window, such as phenytoin, warfarin, and theophylline, are used concomitantly with proton-pump inhibitors. Theoretical concerns about the consequences of chronic administration of proton-pump inhibitors, such as the impact of sustained hypergastrinemia on gastric morphology and the development of atrophic gastritis, have been dismissed. While increased gastrin levels are observed among patients taking proton-pump inhibitors, for the majority they remain within the normal range. After long-term use of the drugs, patients do not appear to be at increased risk of atrophic gastritis or gastric cancer. Helicobacter pylori infection, rather than acid suppression, may be the more important factor for the development of atrophic gastritis. Bacterial overgrowth and altered nutrient absorption resulting from sustained hypochlorhydria induced by chronic administration of proton-pump inhibitors have not been realized as clinical concerns. Not only are proton-pump inhibitors well tolerated during short-term administration, but there also do not appear to be clinically important adverse sequelae associated with their long-term use.

Effect of pelvic-femoral position on vertebral separation produced by lumbar traction.

The purpose of this study was to determine the relationship between hip position and the amount of vertebral separation produced by intermittent lumbar traction. Ten subjects received intermittent lumbar traction at a force of 31.8 kg (70 lb) for 15 minutes in each of three positions of hip flexion (supine): 0 degrees, 45 degrees, and 90 degrees. Vertebral separation was measured on lateral roentgenograms by outlining and marking the vertebral bodies and measuring interspaces with fine-point calipers. Except for the T12-L1 interspace, traction produced greater posterior interspace separation as the angle of hip flexion increased from 0 to 90 degrees. These differences were statistically significant at interspaces L4-5 and L5-S1. We found no systematic changes in anterior interspace distance. To produce maximal posterior vertebral interspace separation, pelvic traction should be applied with the hip flexed 90 degrees.

Predicting to 9-month performance of premature infants.

This article identifies variables found to be predictive of sensorimotor and psychosocial performance in infants at 9 months adjusted age. The subjects were 102 infants with a birth weight of less than 1,500 g, who were participants in an early intervention project. Multiple regression analyses disclosed that poor 9-month performance was related to a lack of special Neonatal Intensive Care Unit (NICU) intervention, to minority group membership, to birth weight, and to performance on selected tests administered in the NICU. We present implications for the early prediction of handicapping conditions and for further research.