Adolescents' perceptions of a health survey using multimedia computer-assisted self-administered interview

OBJECTIVE

To ascertain young people's perceptions of an adolescent health survey when administered by multimedia computer assisted self-administered Interview (M-CASI) through analysis of (1) questionnaire item responses and (2) focus group interviews.

METHODOLOGY

SETTING

Auckland, New Zealand, 1999.

STUDY TYPE

Pilot testing of a 488-item branching questionnaire delivered using a youth-oriented and user-friendly M-CASI interface in a variety of settings using both desktop and laptop computers. Post pilot focus groups of participants identifying their perceptions and experiences of the survey.

SAMPLE

110 school students aged 12 to 18 years.

RESULTS

The mean number of questions answered by participants was 316 with the median time to completion being 48 minutes. On average 65% of the total number of questions were seen and of these 1.5% were deliberately not answered. A high level of acceptability and enjoyment of M-CASI was found in the analysis of focus group responses and agreed with the item responses relating to M-CASI within the questionnaire itself. Participants identified privacy and confidentiality as being particularly important for the honesty of their responses. The passive matrix screens of the computers were popular as they could only be viewed from in front.

CONCLUSIONS

M-CASI is an acceptable instrument for the administration of a youth health survey. Laptop computers with passive matrix screens are able to enhance perceptions of privacy and confidentiality, which may improve honesty of responses.

IMPLICATIONS

M-CASI is now feasible and offers advantages in health surveying.

Extracorporeal liver perfusion using human and pig livers for acute liver failure

BACKGROUND

Patients with fulminant hepatic failure (FHF) often die awaiting liver transplantation. Extracorporeal liver perfusion (ECLP) has been proposed as a method of "bridging" such patients to transplantation. We report the largest experience to date of ECLP using human and porcine livers in patients with acute liver failure.

METHODS

Patients with FHF unlikely to survive without liver transplantation were identified. ECLP was performed with human or porcine livers. Patients underwent continuous perfusion until liver transplantation or withdrawal of support. Two perfusion circuits were used: direct perfusion of patient blood through the extracorporeal liver and indirect perfusion with a plasma filter between the patient and the liver.

FINDINGS

Fourteen patients were treated with 16 livers in 18 perfusion circuits. Nine patients were successfully "bridged" to transplantation. ECLP stabilized intracranial pressure (ICP) and cerebral perfusion pressure (CPP). Arterial ammonia levels fell from a median of 146 to 83 micromol/liter within 12 hr and this reduction was maintained at least 48 hr. Pig and human ECLP lowered ammonia levels equally. Serum bilirubin levels also fell from a median of 385 to 198 micromol/liter over the first 12 hr but the response was not sustained as well with porcine livers. There was no immunological benefit to using the the filtered perfusion circuit.

INTERPRETATION

These data demonstrate that ECLP is safe and can provide metabolic support for comatose patients with fulminant hepatic failure for up to 5 days. While labor and resource intensive, this technology is available to centers caring for patients with acute liver failure and deserves wider evaluation and application.

Using the Internet to enable access to medical conferences

OBJECTIVE

The goal of expanding access to individuals with disabilities to scientific and medical conferences is supported by both the Americans with Disabilities Act and the National Institutes of Health.

DESIGN

Live-streaming video broadcast over the internet is widely available, although it has been used only in a limited fashion by the medical community. A consumer-oriented medical and rehabilitation conference concerning the rare disabling disease, fibrodysplasia ossificans progressiva, was broadcast via the world wide web. The address of a web page was announced before the conference to three computer users' groups that were considered likely to have an interest in the conference. The web page presented a live-streaming video broadcast of the conference. A phone line was installed, thereby allowing viewers to ask questions of the presenters during the question and answer periods.

RESULTS

Sixteen users logged in 83 times to view the conference over a 2-day period. Five (23%) of 22 members of a fibrodysplasia ossificans progressiva internet users' group tuned in from distant places as The Netherlands and Israel.

CONCLUSIONS

The internet is a viable tool to expand access to and increase the participation of individuals with disabilities in scientific and medical conferences. This technology should be used routinely in conferences of interest.

Transmission of live laparoscopic surgery over the Internet2

BACKGROUND

Video broadcasting of surgical procedures is an important tool for education, training, and consultation. Current video conferencing systems are expensive and time-consuming and require preplanning. Real-time Internet video is known for its poor quality and relies on the equipment and the speed of the connection. The Internet2, a new high-speed (up to 2,048 Mbps), large bandwidth data network presently connects more than 100 universities and corporations. We have successfully used the Internet2 to broadcast the first real-time, high-quality audio/video program from a live laparoscopic operation to distant points.

METHODS

Video output of the laparoscopic camera and audio from a wireless microphone were broadcast to distant sites using a proprietary, PC-based implementation of H.320 video conferencing over a TCP/IP network connected to the Internet2. The receiving sites participated in two-way, real-time video and audio communications and graded the quality of the signal they received.

RESULTS

On August 25, 1998, a laparoscopic Nissen fundoplication was transmitted to Internet2 stations in Colorado, Pennsylvania, and to an Internet station in New York. On September 28 and 29, 1998, we broadcast laparoscopic operations throughout both days to the Internet2 Fall Conference in San Francisco, California. Most recently, on February 24, 1999, we transmitted a laparoscopic Heller myotomy to the Abilene Network Launch Event in Washington, DC.

CONCLUSIONS

The Internet2 is currently able to provide the bandwidth needed for a turn-key video conferencing system with high-resolution, real-time transmission. The system could be used for a variety of teaching and educational programs for experienced surgeons, residents, and medical students.

Evaluation of hyperplastic goiter in a colony of Syrian hamsters (Mesocricetus auratus)

Hyperplastic goiter was diagnosed during routine health monitoring of a closed Syrian hamster colony (SG). Adult and juvenile hamsters were affected at a prevalence of 45%. Histologic examination of the enlarged thyroid gland revealed marked follicular cell hyperplasia. Because prevalence of thyroid hyperplasia in this colony exceeded the 6 to 7% prevalence expected in aged hamsters, additional studies were performed to investigate the pathogenesis of this condition. Juvenile male SG hamsters and age- and sex-matched Syrian hamsters that did not have increased prevalence of goiter were obtained from an unrelated source (Fredrick Cancer Research and Development Center [FCRDC]). The thyroid glands of hamsters were evaluated by 123I radionuclide imaging. Eight of 18 SG hamsters and none of the FCRDC hamsters had a diagnosis of enlarged thyroid gland. Serum baseline and post-thyrotropin thyroxine concentrations in SG hamsters were not statistically different from those in FCRDC hamsters. To investigate whether diet played a role in development of hyperplastic goiter, for 6 months 15 FCRDC hamsters were fed the diet that had been fed to SG hamsters (mouse breeder diet), and five were fed a control diet. To determine whether dietary change would result in resolution of goiter, affected SG hamsters were fed a control diet for 3 months. At the end of each feeding trial, thyroid gland uptake of 123I was reevaluated. The amount of 123I taken up by the thyroid glands of FCRDC hamsters fed the mouse breeder diet was not significantly different from that of controls. In contrast, thyroid gland uptake of 123I remained high for all affected SG hamsters fed the control diet. On the basis of results of these investigations, diet was ruled out as the cause of goiter. Also, a diagnosis of euthyroid hyperplastic goiter was made for the SG hamsters. A genetic cause is suspected to play a role in the increased prevalence of goiter in SG hamsters.

Erythroplasia (Queyrat) of conjunctiva

Erythroplasia of Queyrat (EQ) is an epidermoid carcinoma in situ which is histologically identical with Bowen's disease of the skin but involves mucosal surfaces. The lesion is known to occur on the glans penis, the vulva, and the oral mucosa. Two cases of EQ of the conjunctiva that developed several years after radiotherapy for basal cell carcinoma of the eyelids are here reported. The signs and symptoms closely mimicked those of chronic conjunctivitis. The lesions were excised by the microscopically controlled excision of Mohs. It is recommended that biopsy material be obtained in patients who develop a nonresolving chronic conjunctivitis, especially when there is history of radiotherapy of the eyelids.

Sebaceous carcinoma of the eyelid

Meibomian carcinoma is rare but carries a grave prognosis. The lesion may be easily mistaken for inflammatory condition. Therefore, any nodular or recurrent lesion on the eyelid of an elderly person should be examined histologically. A case is presented in which the tumor was successfully treated by the Mohs microscopically controlled excision.

The use of thymoxamine in eyelid retraction

We observed substantial narrowing in 75% of fissures in patients with various types of lid retraction after topical application of aqueous 0.5% thymoxamine (moxisylyte). Even contralateral normal-appearing fissures in thyroid patients responded in this manner. The nonresponders in the lid retraction group included a patient with an orbital pseudotumor and patients with long-standing and stable euthyroid eye disease. No normal subjects' fissures responded greatly to thymoxamine. A substantial reduction in palpebral fissures was seen in all patients with thick extraocular muscles and in 14 of 18 (78%) of all fissures of thyroid patients; the average response was 2.3 mm. This effect may last for five hours after thymoxamine administration. Thymoxamine may be of use as a diagnostic test for thyroid eye disease, and if it can be modified to cause less ocular irritation, it may be beneficial in the medical treatment of eyelid retraction.

Neuromyopathic ptosis: a new surgical approach

Neuromyopathic ptosis is a progressive disorder frequently associated with other ocular abnormalities. These include dry eyes, absent Bell's phenomenon, protractor weakness, and heterotropia. Thus, correction of this ptosis has not been well described and is avoided by many surgeons. Since ptosis usually occurs early in life, correction is of functional, economic, and cosmetic importance. Clinical and histologic findings suggest that degeneration and defects of the levator aponeurosis contribute to the ptosis. During the past two years, we have used the aponeurotic approach to correct neuromyopathic ptosis. We describe 19 eyelids with a minimum one-year follow-up. Most eyelids were purposely undercorrected. A mean lid elevation of 3.3 mm with good symmetric results was obtained. Procedures were performed under local anesthesia. Advantages of this technique are (1) patient cooperation for adjustment of lid height and contour at surgery; (2) preservation of other suspensory structures (Müller's muscle and Whitnall's ligament); (3) easy adjustment of lid height postoperatively; (4) preservation of all tear-producing structures; (5) avoidance of corneal irritation from posterior sutures; and (6) maintenance of anatomic planes, which simplifies reoperation, if necessary. We believe this conservative approach corrects most eyelids with neuromyopathic ptosis.

Aponeurotic ptosis surgery

The recognition of defects in the levator aponeurosis associated with a renewed interest in eyelid anatomy has led to a revival of aponeurotic surgery. We describe our approach with emphasis on techniques that help obtain and maintain avascular planes throughout surgery. The advantages of this approach include preservation of (1) tear-producing structures, (2) Müller's muscle and Whitnall's ligament, and (3) normal anatomical planes and structures of the eyelid. Our results indicate that this technique is the procedure of choice for acquired ptosis cases. It also gives good results in congenital ptosis cases with at least 5 mm of function. Overcorrection at surgery is necessary in all cases. Tucking of the aponeurosis is to be avoided as no raw healing surfaces are obtained. Results in 60 eyelids with a minimum follow-up of one year are presented.

The role of Whitnall's ligament in ptosis surgery

Whitnall's ligament has been described functionally as a check ligament of the levator. Our anatomic dissections and operative findings indicate that this ligament is primarily a support for the upper eyelid and superior orbit. Whitnall's ligament is frequently confused with the levator horns and is unfortunately cut during many ptosis procedures. This is to be avoided because much larger levator resections are required when this ligament's support to the upper lid and the fulcrum effect for the levator are lost. Preserving and enhancing the function of Whitnall's ligament improves the efficiency of the levator, making large levator resections rarely necessary. We have noted no more lid lag than that seen with other forms of levator surgery.

Blood clearance rates of technetium-99m albumin preparations: concise communication

Technetium-labeled human serum albumin (HSA) is extensively used as a cardiac imaging agent. An evaluation of the blood-clearance rates of electrolytically reduced HSA (EHSA) and four stannous-reduced HSA (SnHSA) preparations was conducted in dogs, and was compared with that of radioiodinated HSA (IHSA). The EHSA was found to have a clearance rate only about 1.5 times that of IHSA, whereas the SnHSA agents were cleared at two to five times the rate of IHSA. Thus, EHSA has definite advantages over SnHSA preparations for the purposes of blood-volume determinations required in quantitative cardiac studies and for the reduction of extravascular background in the accurate delineation of cardiac boundaries.

Effect of a magnetic field on the fluorescence produced in irradiated anthracene solutions

The effect of an applied magnetic field on the fluorescence from radiolytic ion recombination has been studied for anthracene in some hydrocarbon solvents. In pulse-irradiated anthracene (10−2 mol dm−3) in squalane, the fluorescence intensity following the pulse increases as a function of applied magnetic field in the range studied, 0 to 0.3 T (0 to 3000 G). At a constant magnetic field strength, the field-induced enhancement of the fluorescence intensity varies with time after the pulse. At high field strengths (0.3 T) the enhancement reaches a maximum of ∼45% about 50 ns after the pulse. Similar effects are observed in cyclohexane but the enhancement is smaller than that in squalane. In benzene solutions the effect is extremely small. These findings are confirmed by observations in continuously gamma-irradiated solutions. In gamma-irradiated solutions of anthracene (10−2 mol dm−3) in squalane, the fluorescence intensity increases with increasing magnetic field and approaches ∼13% enhancement at high fields (>0.1 T). The enhancement is smaller (∼3%) in cyclohexane and very small (<1%) in benzene solutions. 9,10-Dimethylanthracene gives a larger enhancement and anthracene-d10 a smaller enhancement than the parent anthracene at high fields. The results are in general agreement with recent theoretical predictions based on the effect of a magnetic field on the loss of spin correlation of geminate ions pairs prior to recombination.

Use of an in vivo oxygen electrode to determine the effect of hemorrhagic shock on liver oxygen tension

Measurement of arterial and liver tissue oxygen tension (PO2) in animals subjected to hemorrhagic shock demonstrates a significant (p less than 0.001) decrease in tissue PO2 while PaO2 remains essentially unchanged. In fact, marked increase in PaO2 fail to increase tissue PO2 to control levels, demonstrating that the act of increasing FIO2 and/or PaO2 is inadequate treatment of decreased tissue oxygenation in marginal or low flow states. Measurement of tissue PO2 in a variety of clinical situations seems warranted to allow alterations of therapy to improve flow when indicated by inadequate tissue oxygenation. The application of this simple but extremely useful technic should result in improved survival rates in critically ill patients.

Monitoring resuscitation of the injured patient

Physicians are being called on with increasing frequency to initiate resuscitation of the severely injured patient. The medical literature is confusing regarding the best way that this can be done. A study was undertaken to evaluate simultaneously four common, easily measured indexes--blood pressure, pulse rate, central venous pressure, and pulmonary artery pressure. A shock-trauma model employing laboratory-bred beagle dogs was developed. Results indicate that the best single index is pulmonary artery pressure. Certain physiologic principles make central venous pressure an unreliable index.

The effect of hemorrhagic shock on disseminated intravascular coagulation

Experiments tend to confirm the hypothesis that a thromboplastic substance in the blood stream causes little DIC if blood flow is normal. However, if the same quantity of thromboplastic material is present in a slow capillary flow, it will produce DIC and possible death, with a marked clotting defect.

The Vapor Phase Radiolysis of Isopropanol and Water–Isopropanol Mixtures. II. Nitrous Oxide as Electron Scavenger

Nitrous oxide reduces the hydrogen yield from water–isopropanol vapor mixtures by complete scavenging of electrons. Nitrogen is produced over the whole concentration range but the yield at higher isopropanol concentrations is much greater than the electron yield. The results indicate a competition between water and isopropanol for a secondary species resulting from electron attachment to N2O. Reaction of this species with isoprooanol leads to further N2 whereas reaction with water does not. The reactive intermediate is most probably N2O− or N2O2−.

The X-radiolysis of water vapor containing methanol. Effects of some electron and hydrogen atom scavengers

The X-radiolysis of water vapor containing methanol at 125 °C and 1 atm pressure has been studied alone and in the presence of some electron and hydrogen atom scavengers. In water vapor containing methanol only, a plateau value G(H2) = 7.9 ± 0.3 is obtained at all methanol concentrations above 0.5 mole %. Addition of propylene drastically reduces this yield due to efficient scavenging of hydrogen atoms, and values for the total number of H atoms from all precursors g(H)t = 7,5 ± 0.2 and [Formula: see text] are deduced from the competition. An unscavengeable hydrogen yield g(H2) ~ 0.5 is also indicated in mixtures containing propylene. Nitrous oxide and sulfur hexafluoride are found to scavenge electrons efficiently in water vapor containing methanol and the number of hydrogen atoms arising from electron–positive ion recombination is estimated to have a value G = 2.2 ± 0.6. The number of hydrogen atoms arising from processes not involving electrons is g(H) = 5.2 ± 0.3. Carbon tetrachloride reacts efficiently with both electrons and hydrogen atoms, with k(H + CH3OH)/k(H + CCl4) = 0.085. Values of g(H) = 4.9 ± 0.5 and g(H2) = 0.8 ± 0.2 are deduced from mixtures containing carbon tetrachloride.

Effects of electron scavengers in the radiolysis of water vapor

Water vapor irradiated with X-rays in the presence of nitrous oxide gives mainly nitrogen and oxygen together with small amounts of hydrogen and, possibly, hydrogen peroxide. The yield of nitrogen, G(N2) = 3.0 ± 0.3, is constant over a wide range of conditions and G(O2) = 1.6 ± 0.3 after an induction period. The hydrogen yield is constant at low doses with G(H2) = 0.45 ± 0.1, but reaches a steady state at higher doses. The nitrogen yield is equated with the yield of scavengeable electrons in water vapor, the value g(e) = 3.0 ± 0.3 being in reasonable agreement with the theoretical value based on W(H2O) = 30 eV. Addition of other electron scavengers to water vapor containing nitrous oxide suppresses the nitrogen yield by competing efficiently for electrons. On the basis of their efficiency in suppressing the nitrogen yield, limiting values for the relative rates of reaction of N2O, SF6, CCl4, and HCl with electrons in water vapor are obtained and comparisons are made with their known electron attachment cross sections in the gas phase.

Puncture wound pseudomonal osteomyelitis of the foot

Puncture wounds of the foot are commonly seen in the hospital emergency room. They are usually managed appropriately; however, a percentage go on to skin infection with subsequent joint and osseous involvement. This is particularly true in the adolescent patient. This manuscript was written to inform the foot specialist on the etiology, medical, and surgical management of osteomyelitis secondary to Pseudomonas aeruginosa. Also, two pediatric case histories that occurred within 6 months of each other are presented.