Short-term continuous infusion thrombolytic therapy for occluded central nervous venous dialysis catheters.

The necessity of maintaining a strict schedule of dialysis treatments in patients with chronic renal failure dictates that occluded access catheters be restored to full function in a timely and cost-effective manner. The records of 22 consecutive patients receiving outpatient treatment for occluded hemodialysis catheters at Osteopathic Medical Center of Texas were reviewed by the authors. Each patient had 100,000 units of urokinase in 50 ml normal saline instilled over 30 minutes through the occluded catheter. In most instances the dose was divided to allow 35 ml to the proximal port and 15 ml to the distal port. The maximum sustained blood flow rate on dialysis was recorded for each patient. The mean maximum sustained blood flow rate improved from 150 ml/min +/- 79 ml to 261 ml/min +/- 62 ml. Following infusion, improvement was obtained in 19 of 22 patients, with 14 catheters delivering blood flow greater than 250 ml/min. The total cost per treatment was $316. No adverse events were experienced. Thrombotic occlusion of extended use hemodialysis catheters can be rapidly and safely relieved in a cost-effective manner with little delay in scheduled dialysis treatments.

A survey of facial paralysis: etiology and incidence.

Facial paralysis has numerous etiologies ranging from the most common, Bell's palsy and trauma, to rare tumors and congenital anomalies. This paper divides the etiologies of facial paralysis into five major classifications: idiopathic, traumatic, infectious, neoplastic and neurologic. The incidence of each of these classifications has been estimated from incidence rate information published in the United States and abroad. Using this information, an estimate of the incidence rate has been determined. This information was previously untabulated, thus making statistical analysis nearly impossible regarding this disorder.

Evaluation of the Hall-effect sensor for determination of eyelid closure in vivo.

A small device to detect eyelid closure was designed on the basis of a Hall-effect sensor. Accurate sensing of normal eyelid closure is required to develop a prosthetic eyelid closure device for patients with paralyzed orbicularis oculi muscles. In this study, six rabbits had the sensors surgically implanted. A Hall-effect sensor, a small device that measures magnetic fields, was implanted in the inferior eyelid near the ciliary margin. An opposing magnet was implanted in the upper eyelid. Thus, as the eyelid closes, the output of the Hall-effect sensor will increase. This output voltage was monitored weekly. During the first 5 weeks the output of the Hall-effect sensor decreased slightly but then reached a steady state for the duration of the experiment. This study suggests that the Hall-effect sensor could be used to detect normal eyelid closure in an implantable facial reanimation device.

Determination of palpebral closure using a Hall sensor magnet pair.

A small device that can detect eyelid closure was designed using a Hall sensor and magnet. The ability of the sensor to differentiate blinks from saccadic motion is of vital interest in development of a device to alleviate complications of facial nerve paralysis. Twelve physically normal human subjects were used in this study. A small Hall sensor (3 x 2.5 x 1.1 mm), a device that detects magnetic fields, was attached to the lower eyelid near the lid margin, and an opposing small magnet (3 x 2 x 1 mm) was attached to the upper eyelid, also near the lid margin. Output potentials from the Hall sensor were monitored during eye blinks and saccadic eye movements to correlate sensor potentials with eye movements. Results indicate that the Hall sensor is effective at determining palpebral closure and discriminating eye closure from other eye movements. Therefore, we conclude that the Hall sensor is a reliable means for determining palpebral closure and is ideally suited for use in a facial prosthesis that uses the normal blink as a trigger to reanimate the contralateral paralyzed eyelid.

Ciprostene and indomethacin partially reverse the mechanisms of distal end necrosis in the rat random skin flap.

Survival of random skin flap distal end depends on hemodynamic, cellular, and coagulation mechanisms. This study was designed to evaluate whether administration of ciprostene, a stable prostaglandin I2 analogue, and indomethacin, a cyclooxygenase-hydroperoxydase enzyme inhibitor, would improve the survival rate of random skin flaps. Forty-five male rats were divided into nine groups and injected with sesame oil (control), ciprostene (20 micrograms/kg/day), and/or indomethacin (2 mg/kg/day). Injections were done before (pretreatment for 4 days), after (posttreatment for 6 days), and before/after (pre/posttreatment for 4 and 6 days, respectively) the elevation of random dorsal skin flaps. In the pretreatment and pre/posttreatment studies, the flap survival rate of all drug-injected groups was significantly higher than that of the control group (p less than 0.02). In addition administration of ciprostene alone yielded a trend of better flap survival rate, which, however, was not statistically significant (p less than 0.12). Of interest in the posttreatment study, only the simultaneous administration of ciprostene and indomethacin significantly increased skin flap viability compared with the other groups (p less than 0.02). Therefore, the results demonstrated that administration of ciprostene and indomethacin either alone or together partially reversed the pathophysiological mechanisms that cause necrosis of random skin flap distal end. These pharmacological changes significantly improved random skin flap survival rate.

The use of 5-aminoimidazole-4-carboxamide riboside (AICA riboside) to improve random skin flap viability in the rat model.

Several experimental studies have demonstrated that granulocytes have an important role in causing the necrosis of ischemic tissue by capillary plugging and superoxide radical formation. Adenosine is spontaneously released by ischemic cells and inhibits the granulocytic superoxide radical formation. 5-Aminoimidazole-4-carboxamide riboside, a naturally occurring by-product in purine biosynthesis, stimulates the release of ischemic cell adenosine and indirectly blocks the granulocyte-induced tissue necrosis. 5-Aminoimidazole-4-carboxamide riboside (10-500 mg/kg) was administered intraperitoneally in a blinded fashion once (single dose, 30 minutes before surgery) or twice (double dose, 30 minutes before and 5.5 hours after surgery) in groups of rats. The controls received intraperitoneal saline solution in the same fashion. Each rat underwent the elevation of a caudally based random skin flap. The flap viability was determined in a blinded fashion on the seventh post-operative day and statistically compared by Fisher's exact test. When 300 or 500 mg/kg of 5-aminoimidazole-4-carboxamide riboside was given as a single dose, the mean percentage of rat skin flap necrosis (19.4% +/- 3.1% and 19.6% +/- 4.2%, respectively) was lower but not significantly different from that of the control group of rats (29.3% +/- 2.7%) (p less than 0.08). Additionally, two doses of 500 mg/kg of 5-aminoimidazole-4-carboxamide riboside yielded a mean percentage of rat skin flap necrosis (12.24% +/- 4.58%) much lower (21.68% +/- 3.18%) than that of the control group of rats (p = 0.056). Our blinded fashion study demonstrated an almost statistically significant reduction of random skin flap distal necrosis after intraperitoneal injection of high doses of 5-aminoimidazole-4-carboxamide riboside.(ABSTRACT TRUNCATED AT 250 WORDS)

Electrical stimulation treatment of dog's denervated orbicularis oculi muscle.

In this investigation, the electrophysiology and pathology of denervated orbicularis oculi muscles have been studied in dogs during chronic electrical stimulation. The orbicularis oculi muscles were unilaterally denervated in 8 dogs, and 4 of these muscles were directly stimulated on a daily basis for 75 days. No difference in minimum stimulus intensities evoking orbicularis oculi muscle twitch contraction appeared between denervated treated and nontreated muscles. A significant reduction of minimum stimulus intensities evoking upper eyelid complete closure (blink), however, was found in the denervated treated muscles between 10 and 30 days (p less than 0.01). At 28 and 75 days, orbicularis oculi muscle biopsies showed no difference in muscle fiber diameter between denervated treated and nontreated muscles. At 75 days, type II muscle fiber distribution, however, was significantly increased in denervated treated muscles compared with denervated nontreated muscles (p less than 0.01). These findings of orbicularis oculi muscle electrophysiology were consistent with a transient reversal of denervation changes by electrical stimulation, partially supported by muscle biopsies.

Restoration of paralyzed orbicularis oculi muscle function by controlled electrical current.

A canine model of facial nerve paralysis was studied to apply controlled electrical current to the peripherally denervated orbicularis oculi muscle, in the attempt to effectively restore the absent function of this denervated muscle. After unilateral facial nerve neurotmesis was performed in eight dogs, the denervated orbicularis oculi muscles of four dogs were electrically stimulated for 75 postoperative days (40 min/day). Denervated and normal orbicularis oculi muscles were electrophysiologically studied and compared with the Student t test. During the study period, minimum closure of denervated treated orbicularis oculi muscles was evoked with average stimulus strength (80-ms duration) of 1.61 +/- 0.22 log mA x ms, not significantly different from that of denervated nontreated or normal orbicularis oculi muscles. From days 10 through 30 only, maximum closure of denervated treated orbicularis oculi muscles was achieved with mean pulse strength (80-ms duration) of 2.37 +/- 0.09 log mA x ms, significantly lower (P less than .01) than that evoking the same type of contraction from denervated nontreated muscles (80-ms duration, mean 2.83 +/- 0.10 log mA x ms). In addition, denervated treated muscle pulse strength eliciting maximum contraction was not significantly different from that of normal orbicularis oculi muscles during the same period. This finding was not observed, however, from day 40 through the end of the study. This investigation demonstrates (1) the transient reversal of denervation changes of paralyzed orbicularis oculi muscle by daily electrical stimulation, and (2) the feasibility of restoring orbicularis oculi muscle function by controlled electrical current.

Blink reflex recovery after electrical stimulation of the reinnervated orbicularis oculi muscle in dogs.

The paralytic lagophthalmos following palpebral nerve neurotmesis and consequent peripheral denervation of the orbicularis oculi muscle is often associated with harmful effects on the exposed cornea. This study investigated how daily electrical stimulation affects the blink reflex recovery of this muscle after its reinnervation. Six dogs underwent unilateral facial nerve neurotmesis with immediate epineurial repair of the palpebral nerve. Three dogs were randomly chosen to receive electrical stimulation of the reinnervated orbicularis oculi muscles for 75 days. The remaining 3 dogs were controls (nonstimulated muscles). During the study, the reinnervated orbicularis oculi muscle electrophysiology and blink reflex recovery were investigated. The Student's t test was used for statistical analysis. The results can be summarized as follows: (1) between 30 and 50 days, the minimum mean stimulus intensities evoking complete up-per palpebral closure of the stimulated muscles were significantly lower than those of the nonstimulated muscles (p less than 0.01) and (2) the stimulated muscles recovered complete closure of the interpalpebral fissure (blink reflex) at 49.6 days, significantly earlier (p less than 0.01) than the nonstimulated muscles (72.6 days). It is concluded that daily electrical stimulation of the orbicularis oculi muscles, if started immediately after epineurial repair of the palpebral nerve neurotmesis, promotes a faster blink reflex recovery in the dog model.

Electrophysiological study of the denervated orbicularis oculi muscle in dogs.

This study investigated the electrophysiology of the denervated orbicularis oculi muscle and its clinical application. Orbicularis oculi muscle denervation was achieved by complete transection of the seventh nerve in ten dogs. The parameters studied were the electrical requirements needed to cause a minimal perceptible contraction (twitch) and a complete eyelid closure (blink). Twitch and blink curves were generated. The findings are summarized as follows: (1) Minimum intensities for direct twitch of denervated orbicularis oculi muscle were significantly lower than intensities of normal orbicularis oculi muscle twitch (p less than 0.01) when long stimulus duration (5 to 400 ms) was used. (2) Minimum intensities for direct blink of denervated orbicularis oculi muscle were not significantly different from stimulus intensities for blink of normal orbicularis oculi muscle if long stimulus duration (5 to 400 ms) was used. Twitch and blink curves could be used to clinically follow the orbicularis oculi muscle movement return after operations performed in patients affected by lagophthalmos.

Hand infections in dental personnel.

In an attempt to study the incidence of hand infections in dental personnel, a standardized survey was submitted to 715 dental professionals and hygienists throughout the state of Nebraska. Of those surveyed, 508 responded (71 percent). Ninety-eight of the 508 respondents reported an infection (19.29 percent). The rate of infection was found to correlate positively with the number of patients seen per week. The rate of infection was increased in respondents with chronic disease (e.g., diabetes mellitus) versus those without chronic disease (33.33 vs. 18.59 percent). In the dental professionals surveyed, it was found that the rate of infection in those who did not routinely wear surgical gloves was significantly greater than in those who did (28.6 vs. 17.6 percent). The morbidity of infections acquired in dental practice can be substantial. A percentage of individuals must leave their practice for surgical treatment. A number have acquired hepatitis B (although none in this study), and exposure to the HTLV-III is possible. We conclude that some protection from infection can be achieved with the routine use of surgical gloves, and this practice should be considered by all, particularly those with chronic disease.

The delineation of adriamycin extravasation using fluorescence microscopy.

Frozen-section fluorescence of Adriamycin extravasation in skin has been demonstrated to be an efficient method of detecting Adriamycin in tissue. Appropriate use of this technique as a guide to surgical treatment of infiltration is feasible, but it must await clinical trials.

Bilobed latissimus dorsi flap for a decubitus ulcer.

A case is presented of a bilobed latissimus dorsi flap. The advantage of this flap is to close a large defect without having to resort to a skin graft for closure of the donor-site defect. The advantages of this procedure are as follows: Well-vascularized, stable coverage for decubitus ulcers. Acceptable cosmetic deformity. Avoidance of a skin graft. Decreasing the length of hospitalization.