Inhibitory effects of estrogen on stimulated salt appetite in rats.

Adult male rats consumed 50-150% more 0.5 M NaCl solution than females did during a 7-hr drinking test when robust salt appetite was elicited by dietary sodium deprivation for 8 days, daily injections of deoxycorticosterone, or adrenalectomy followed by 2 days of sodium deprivation. In contrast, male rats drank much less saline after systemic treatment with the natriuretic agent furosemide, adrenalectomy followed by 1 day of sodium deprivation, or sc treatment with colloid solution after 2 days of sodium deprivation, and female rats drank comparably small volumes. Conversely, 30-day-old prepubescent male and female rats showed equally robust salt appetites after 8 days of sodium deprivation. These and other findings support an inhibitory role of estrogen on salt appetite in rats, which appears to occur only when the appetite is especially pronounced.

Amblyopic quasi-blindness for image structure.

Human amblyopes display reduced contrast sensitivities, suffer from perceptual distortion, and their letter acuities are worse than is predicted from grating visibility. We sought the origin of these dysfunctions by measuring normal and amblyopic sensitivities to various forms of well-defined image distortion, namely band-limited phase quantization, phase quantization with additional amplitude modulation, and grey-scale modification. Our results prove the existence of an amblyopic quasi-blindness to image structure, that cannot be explained in terms of contrast detection. We discuss these findings within the computational scheme of image decomposition into local amplitude and local phase values. they are consistent with the assumption of amblyopic eyes beings impaired in processing local phase but having the local amplitude (or "energy", possibly at reduced gain) at their disposal. Phrased in physiological terms, we propose a scheme of complex-cells-only vision in amblyopia. We also provide a demonstration of how amblyopic eyes may see the test stimuli and natural images by generating local amplitude and phase representations at limited phase resolution.

Effectiveness of wound care products in the transmission of acoustic energy.

BACKGROUND AND PURPOSE: Ultrasound is often recommended in the treatment of people with partial and full-thickness wounds. Many treatments are performed over a hydrogel sheet or semipermeable film dressing. The purpose of this in vitro study was to examine the effectiveness of 4 hydrogels (Nu-Gel, ClearSite, Aquasorb Border, and CarraDres) and 4 film dressings (CarraSmart Film, J&J Bioclusive, Tegaderm, and Opsite Flexigrid) in ultrasound transmission. METHODS: The amount of sound energy transmitted through each product and interposed pig tissue was measured using an oscilloscope to display the intensity of sound energy delivered by the transducer. Five intensities at a frequency of 3.3 MHz were studied. RESULTS: Results were expressed as the mean ((SD) percentage of voltage transmitted compared with a gel baseline. Nu-Gel was the most efficient hydrogel (77.2%(4.6%), followed by ClearSite (72.0%(2.2%), Aquasorb Border (45.3%(2.1%), and CarraDres (42.8%(5.9%). The 4 film dressings, in order of efficiency, were CarraSmart Film (60.5%(4.4%), J&J Bioclusive (53.2%(2.4%), Tegaderm (47.1%(2.3%), and Opsite Flexigrid (31.5%(4.0%). CONCLUSION AND DISCUSSION: Transmissivity of wound care products used to deliver acoustic energy during ultrasound treatment of wounds varies greatly among dressing products. We believe that clinicians can use our findings as a part of the clinical reasoning process that they use to select an optimal wound dressing.

Mechanisms of blunt perineal injury in female pediatric patients.

BACKGROUND/PURPOSE: Controversy persists regarding the causes of and the morbidity associated with blunt perineal injuries in children. The purpose of this study was to determine the most common mechanisms of blunt perineal trauma in female pediatric patients and to define the subset of patients that may benefit the most from an examination under anesthesia (EUA). METHODS: Nearly 4,450 female pediatric patients were entered in the Pennsylvania Trauma Outcome Study database between 1993 and 1997. The mechanism and extent of perineal injury, surgical repair, and associated injuries were examined for all girls 0 to 16 years of age with a diagnosis of blunt perineal trauma. RESULTS: A total of 358 girls experienced blunt perineal trauma. Motor vehicle crashes (MVC) accounted for the majority of injuries in all age groups. Falls and bicycle-related injuries were significantly more prevalent in children less than 9 years of age, and assaults in children 0 to 4 years. Head trauma was the most common associated injury in children less than 15 years. Children less than 10 years of age required surgical repair of their perineal injuries more frequently than their older counterparts. Perineal injuries caused by falls, assaults, or playground-related equipment were more likely to require surgical repair than those caused by other mechanisms. CONCLUSIONS: Perineal injuries that require surgical repair occur predominantly in patients less than 10 years of age who sustain blunt perineal trauma from a variety of causes, but rarely MVC. Thus, such patients should undergo aggressive evaluation, including EUA, especially if they present with perineal bleeding, hematoma, or swelling. Furthermore, perineal injuries in children under 4 years should raise the suspicion of abuse.

Use of verapamil for the symptomatic treatment of microscopic colitis.

BACKGROUND: The initial use of verapamil for the symptomatic treatment of microscopic colitis is reported. STUDY: Four patients diagnosed with microscopic colitis who failed to respond to conventional therapy are presented. RESULTS: Verapamil was instituted, resulting in prompt and sustained resolution of symptoms. CONCLUSIONS: This therapy was convenient and well tolerated.

Practical management of acute diarrhea.

A careful history and physical examination are usually enough to assess illness severity, the need for further labortory tests, and often the cause. Supportive treatment generally suffices However, antibiotic or probiotic therapy should be considered in selected patients.

[Comparison of knee and functional outcomes of patients lost to follow-up with patients remaining in a prospective total knee arthroplasty study]. / Ein Vergleich der klinischen und funktionellen Ergebnisse von ausgeschiedenen mit in einer prospektiven Knieendoprothesenstudie verbliebenen Patienten.

PURPOSE: Survival analysis is correct when patients lost to follow-up are as healthy as patients still being followed. Therefore, the results of patients who missed the follow-up visits were determined and compared with the results of the patients still in the study. Revision surgery and the reasons for failing to reattend the follow-up visits were recorded. METHODS: Of 680 unconstrained total knee arthroplasties implanted between 1989 and 1994 with yearly patient evaluation according to the Knee Society 53 patients with 60 implants died, 17 patients with 19 implants could not be used for the study and 21 patients with 24 implants were interviewed by telephone. 56 patients with 61 implants lost to follow-up were examined by visiting them at their homes (drop-outs) and compared to the 460 patients with 516 implants still in the study. RESULTS: The drop-outs were older at surgery and had more medical infirmity than the remaining patients. Drop-outs had a lower mean function score and a tendency to a lower mean knee score at follow-up compared with the patients in the study. No revision surgery was performed in drop-out knees. Reasons for not reattending the follow-up were mainly long travel and health. CONCLUSIONS: Patients reattending a study are healthier than drop-outs. This censoring mechanism limits correct survival analysis. A complete follow-up of patients and separate assessment of knee and functional status with reliable and valid instruments is required.

The need for a dual rating system in total knee arthroplasty.

The sequential course of the knee score and functional score of the Knee Society rating system of 276 press fit condylar modular unconstrained total knee arthroplasties performed for osteoarthritis between June 1988 and December 1992 was documented prospectively. The knee score increased significantly and stayed on a constant level from 2 years on, whereas the function score reached a maximum at 2 years and declined subsequently. Multiple regression analysis was performed testing the statistical significance and correlation of preoperative predictors with criteria at followup to determine their influence on outcome. Preoperative predictors were knee score and function score, body mass index, age, gender, patient category, and implant factors. Criteria studied were pain, knee score, and function score at 2 years followup. The function score is influenced significantly by the walking distance, age, body mass index, and patient category correlating moderately. The knee score is not affected by any of these factors. Pain was found to correlate low with the walking distance. Rating systems are influenced by numerous factors linked to the patient's general health and condition. Their impact on the overall result can be controlled by separate rating of the knee score and function score as the dual Knee Society rating system does. Scoring systems adding up knee and functional rating to an overall result should not be used. There is a need for additional improvement of total knee arthroplasty rating such as patient based evaluation and establishing reliability and validity.

[Follow-up studies after bicondylar superficial replacement of rheumatoid knee joint destruction]. / Verlaufsbeobachtungen nach bicondylärem Oberflächenersatz bei rheumatischen Kniegelenkdestruktionen.

This study documents prospectively the Knee Society knee- and function score of 28 patients with rheumatoid arthritis with 34 PFC unconstrained total knee arthroplasties from preoperative values on at yearly intervals. The average follow-up period was 3.4 years (range 2-5.5 y). At last follow-up over 80% of the knees were painfree. All but one patient could walk more than 500 m. Knee and function score increased significantly from 30.1 resp. 35.0 to 83.8 resp. 74.6 (P < 0.000001). Postoperatively the knee score rose soon to a constant level whereas the function score showed a continuous slow increase up to 5 years. We observed one deep venous thrombosis and one subluxation. At an intermediate follow-up rheumatoid knees are clinically and functionally successfully operated on using an unconstrained TKA. Pain relief is excellent. We recommend the use of a scoring system assessing knee and functional results separately.

[Is use of the Knee Society Roentgenographic Evaluation and Scoring System for radiologic control of knee prostheses reliable?]. / Ist die Verwendung des Knee Society Roentgenographic Evaluation and Scoring System zur radiologischen Kontrolle von Knieendoprothesen sinnvoll?

PURPOSE: To follow the radiographic parameters of prosthetic loosening of the Knee Society Roentgenographic Evaluation and Scoring System (KSRESS) and to test their clinical relevance. METHODS: This prospective study documents the use of the KSRESS and clinical rating system in 333 primary posterior cruciate retaining PFC total knee arthroplasties preoperatively, at 3 month and at yearly intervals postoperatively. The average follow-up period was 3.2 years (range 2-5.5 y). RESULTS: The average component position and alignment angles remained unchanged at biomechanically correct angles during the follow-up period. Radiolucent lines were observed regularly at the edges of the tibial and femoral components. The average total radiolucent lines score decreased for the tibial component. Patellar and femoral lucencies remained unchanged. The total radiolucent lines scores did not correlate with postoperative pain, body-mass-index, alignment, stability, knee and function score. Four revisions, one with relevant radiolucent lines, had to be performed. CONCLUSIONS: The KSRESS is a useful tool. Standardisation of roentgenograms is mandatory. The PFC arthroplasty, the operative technique and the instruments ensure a biomechanically correct implantation.

Heterotopic ossification after total knee arthroplasty. 54/615 cases after 1-6 years' follow-up.

We found heterotopic ossifications in 54 (9%) of 615 cases after total knee arthroplasty. The largest ossifications were located in the anterior distal femur. In 12 cases smaller ossifications were found in other knee regions. The development of heterotopic ossification showed a positive correlation with hypertrophic arthrosis and a negative correlation with rheumatoid arthritis. We propose a new 3-grade classification which refers only to the anterior distal femoral region. Grade III heterotopic ossifications occurred in 4 patients (4 knees) who had clinical symptoms; 2 were successfully reoperated with removal of the ossifications. Prophylaxis should be considered in patients with marked hypertrophic arthrosis or marked periosteal damage to the anterior distal femur.

Extended indications for placement of an inferior vena cava filter.

To study the morbidity and mortality rates after placement of an inferior vena cava filter and to define the appropriate indications for interruption of the inferior vena cava, the records of all patients who underwent insertion of a Greenfield filter during the decade January 1978 to December 1987 were reviewed. Patients were designated as having either a traditional or extended indication for placement of an inferior vena cava filter. Two hundred sixty inferior vena cava filters were placed in 264 attempts, with no deaths related to insertion of the filter. An extended indication was the primary reason for placement of the Greenfield filter in 66 (25%) of the patients. In patients with extended indications there were no cases of air embolism or filter misplacement and only three wound complications (4.5%). Pulmonary embolism after insertion of the inferior vena cava filter occurred in three patients (4.5%), with one fatality (1.5%). Inferior vena cava occlusion was documented in three cases (4.5%), and manifestations of the postphlebitic syndrome in early follow-up were present in two patients (3.0%). As the procedures to prevent fatal pulmonary embolism have become safer, more efficacious, and less morbid, the number of patients in whom the potential benefits of insertion of an inferior vena cava filter outweigh the risks has become larger. Our results support the liberalized use of Greenfield filters in those patients who do not necessarily have one of the traditional indications for placement of an inferior vena cava filter but are at a high risk of having a fatal pulmonary embolus.

Risk factors and predictors of mortality in children after ejection from motor vehicle crashes.

PURPOSE: Mortality after ejection from a motor vehicle crash (MVC) has been studied extensively in adults. The magnitude of this problem in children is relatively unknown. We retrospectively examined fatalities resulting from ejection after MVC in the state of Pennsylvania to define risk factors and predictors of mortality in children. METHODS: The records for all patients 0 to 16 years of age involved in an MVC and entered in the Pennsylvania Trauma Outcome Study between 1993 and 1997 were reviewed. We examined mortality, length of hospitalization, major injuries sustained, and impact of safety restraint devices. Significant differences were determined using chi2 test. RESULTS: There were 2,298 children involved in MVCs during this period; 189 were ejected. A total of 77% of the ejected passengers were greater than 10 years of age, 16% were 0 to 4 years of age, and 7% were 5 to 9 years of age. Overall, 88% of the ejected occupants were unrestrained. Ejection nearly tripled the overall mortality rate and significantly increased the Injury Severity Score for each age group. Infants and children 0 to 4 years of age had the highest fatality rate despite having a lower Injury Severity Score than all other age groups. Head injuries accounted for the majority of deaths in all age groups. Children older than 10 years of age had a higher incidence of associated chest, abdominal, and pelvic injuries. CONCLUSION: Our data show that most children ejected from MVCs were either unrestrained or improperly restrained. Head injuries were the most common cause of death in all age groups. Greater public awareness through educational programs targeting parents and children at risk may reduce this serious problem.