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Biomedical subjects

N I Spielholz

Publications and source records attributed to N I Spielholz.

17 recordsLinked to original sources
PubMed2001

Comparison of EMG activity of medial and lateral hamstrings during isometric contractions at various cuff weight loads.

Since both the medial head (MH) and lateral head (LH) of the hamstring muscles contribute to knee flexion, this study investigated whether the relative electrical activity of these heads remained constant with respect to each other or changed during isometric contractions at five different resistance levels. The relative electrical activity of these two heads was determined by comparing their integrated EMG (iEMG). Forty-two volunteers with no history of right lower extremity injury or disease, between the ages of 18 and 35, were studied. Following motor point location, surface electrodes were placed over the MH and LH. Subjects, positioned prone, flexed the knee to 45 degrees using a sawhorse as a tactile cue to help maintain this position. Three recordings, 8 s in length, were taken at each subject's maximum isometric contraction and then using cuff weights of 1, 3, 5, and 7% of their body weight. The average of the three recordings was used in the analysis. During maximum isometric contraction (at 45 degrees of knee flexion), the LH contributes a significantly greater percent of the total iEMG (63.4%) than the MH (P < 0.0001). Furthermore, within the four submaximal levels tested, the LH's contribution was significantly greater than the MH (P < 0.01). During submaximal isometric contractions, the LH percent contribution to total iEMG was less than its contribution during maximal isometric contraction, all P values < 0.005. As a result, during these same submaximal isometric contractions, the MH contribution to total iEMG was greater than its contribution during maximal isometric contraction, all P values < 0.005).

Adolescent↗
PubMed1996

Microwave diathermy treatment for primary dysmenorrhea.

This case report documents the use of microwave diathermy in a 31-year-old woman who had had primary dysmenorrhea since menarche began at age 13 years. For 18 years, she had severe monthly pain, frequently resulting in emergency department admissions and 1 to 3 days lost from work. Conventional treatments, including pain-relieving drugs, anti-inflammatory drugs, muscle relaxants, superficial heat, and oral contraceptives, had all been unsuccessful in relieving or abating the intense and debilitating pain. Microwave diathermy (45 W total power) was administered for 20 minutes each month on the day symptoms began (usually the first day of menstruation). Over a 7-month interval, diathermy was followed by almost-immediate and long-lasting relief of symptoms. During the 7 months of treatment, the patient lost no workdays due to severe pain. This case demonstrates the potential use of microwave diathermy as an effective treatment for women with this condition.

Adult↗
PubMed1995

Lower extremity SEPs.

Explore the source record for details and available documents.

Evoked Potentials, Somatosensory↗
PubMed1993

Electromyographic study of overuse syndromes in sign language interpreters.

Sign language is the fourth most common language in the United States; this mode of communication involves sustained, repetitive use of the hand, wrist, and arm. Signers, therefore, are at risk of overuse disorders as carpal tunnel syndrome (CTS) and ulnar neuritis (UL). Using electrodiagnostic methods, the prevalence of hand nerve entrapments in signers was investigated. Thirty-three signers, six of whom were deaf, were compared to 21 age-matched controls (mean age = 31 and 29 years; respectively). Demographics were obtained by questionnaire. Physical examination and nerve conduction studies followed; 78 hands were examined. No significant mean differences in median motor or sensory latencies discriminated signers from controls. Although no signer's median SNAP latency was greater than 2 SDs from controls, some signers could be considered "abnormal" by other published criteria (eg, median/ulnar mid-palmer comparisons). Using these, 10 of 33 signers had mild abnormalities, five suggestive of CTS, three of UL, and two of both; of controls, two had CTS and two UL. The ratio of electrodiagnostic abnormalities did not differentiate the two groups (p > .05). Reports of hand and/or wrist pain were extremely high in interpreters (nondeaf signers) and were linked to EMG findings (p < .05). Deaf signers, even those with ED findings consistent with CTS, all reported no symptoms, possibly because their signing is less stressful or learned at an earlier age.

Carpal Tunnel Syndrome↗
PubMed1990

Tenotomy-induced motor endplate alterations in rat soleus muscle.

The effects of tenotomy on the ultrastructure of rat soleus muscle motor endplates were examined both qualitatively and quantitatively. Rat soleus muscle was studied 2 weeks following tenotomy and compared with normal littermates. The motor endplates from the tenotomized muscles were found to exhibit both degenerative and regenerative changes. Degeneration consisted of postjunctional fold breakdown, exposed junctional folds, myelin-like bodies within the sub-junctional sarcoplasm, and dense bodies within the Schwann cell cytoplasm. The regenerative changes consisted of several small nerve terminals occurring within the same primary synaptic cleft and several axons wrapped by the same Schwann cell. The results demonstrate that tenotomy induces denervation-like changes at endplates that lead to terminal sprouting within the neuromuscular junctional area and remodelling.

Animals↗
PubMed1988

The effect of early functional activities on experimentally tenotomized Achilles tendons in rats.

Muscle atrophy, joint stiffness, osteoarthritis, infection, skin necrosis, atrophy and ulceration of joint cartilage and tendocutaneous adhesion are familiar complications produced by prolonged immobilization of surgically repaired tendon ruptures. Because these complications may be minimized by limited immobilization and early functional activities, we studied the effects of early weight bearing on the maximum breaking strength of tenotomized tendons in 30 Wistar rats. After tenotomy, the right hind limb of the first group of 10 rats was immobilized for the first 5 days. Thereafter their casts were removed to permit weight bearing for the next 3 days. In a second group of 10 rats, casts were removed 2 days after surgery, the animals were allowed 3 days of unrestricted use of the limb, and then the limbs were re-casted for another 3 days. In a third group of 10 rats the right hind limbs were casted throughout the first 8 days of healing. At the end of this time, strain gauge measurements showed that tendons in the second group healed significantly stronger and without rerupture than those in either of the two groups. Although healing time in rats does not directly translate to humans, our findings suggest that function may return faster in humans, as, for example, following Achilles tendon rupture, if a better combination of immobilization and activity could be found than is currently employed.

Achilles Tendon↗
PubMed1987

Low-intensity pulsed galvanic current and the healing of tenotomized rat achilles tendons: preliminary report using load-to-breaking measurements.

The possible beneficial effects of low-intensity, pulsed galvanic currents on the healing of tenotomized Achilles tendons was investigated in three groups (20 animals each) of male Sprague-Dawley rats. Treatments via implanted electrodes were given once daily for 15 minutes over a two-week period. Although a portable high-voltage galvanic stimulator was used, stimulus intensity was only 75 microA at a frequency of 10/sec. Tendons were tested after two weeks for the load required to rebreak them at the original tenotomy site. The group treated with anodal current withstood significantly greater loads (p less than 0.001) than did either the group which healed normally (ie, without stimulation) or the group treated with cathodal current.

Achilles Tendon↗
PubMed1984

Chronic neurological deficits and Nesacaine-CE--an effect of the anesthetic, 2-chloroprocaine, or the antioxidant, sodium bisulfite?

Chronic neurological deficits have been described in patients after presumed accidental subarachnoid injection of 2-chloroprocaine-CE (Nesacaine-CE; N-CE) intended for epidural block. This study investigated the possible role of pure 2-chloroprocaine (2-CP) and sodium bisulfite, two components of Nesacaine-CE, in causing these complications when injected separately into the lumbar subarachnoid space of neurologically intact awake rabbits. Repeated 2-4-mg spinal anesthetic doses of pure 2-CP in lactated Ringer's solution did not produce chronic hindlimb paralysis even though accumulated doses reached 50 mg. However, 1.2-2.4 mg of sodium bisulfite, the antioxidant in N-CE added to prolong shelf-life, resulted in irreversible hindlimb paralysis in 12 out of 14 animals. This amount of bisulfite is contained in 12-24 mg of 2% N-CE. The demonstration that persistent paralysis resulted from low dosages of sodium bisulfite contained in commercially available 2-CP requires reevaluation of the suitability of this antioxidant for products prepared for intrathecal use.

Anesthetics, Local↗
PubMed1973

Localization and properties of the cholinesterase in crustacean muscle.

Cholinesterase (ChE) activity is present in crustacean muscle extracts. However, since acetylcholine (ACh) is not a neuromuscular transmitter in these animals, the role and exact localization of ChE was unknown. The histochemical localization of the enzyme was studied in whole muscle and in the sarcoplasmic reticulum fraction of the extract, 50-microm frozen sections of glutaraldehyde-fixed crayfish tail flexor muscle were incubated with acetylthiocholine (ATC) as substrate, and examined under the electron microscope. After some modifications in published techniques, dense deposits were found associated with the sarcolemma, sarcolemmal invaginations, and transverse tubules. No deposits were found in 10(-4) M eserine, or if butyrylthiocholine (BTC) was substituted for ATC. The vesicles in the sarcoplasmic reticulum fraction which demonstrate the activity must represent minced bits of these membranes. Using a spectrophotometric method, the kinetics of the crustacean muscle enzyme was compared to the acetylcholinesterase (AChE) on mammalian red blood cells and in the lobster ventral nerve cord. Surprisingly, and contrary to previous reports, the crustacean muscle enzyme did not demonstrate substrate inhibition. While a number of similarities to AChE were found, this lack of substrate inhibition makes questionable an unequivocal similarity with classical AChE.

Animals↗
PubMedDate not supplied

Somatosensory evoked potentials during decompression and stabilization of the spine. Methods and findings.

As part of a study to determine if decompressive surgery benefits patients who have incomplete lesions of the spinal cord, the somatosensory evoked potential (SEP) has been employed as an intraoperative spinal cord monitor. This procedure was used to see if decompression results in any rapid changes in spinal cord conductivity and to correlate these findings with the patient's subsequent clinical course. In addition to trauma, however, other factors also affect the SEP, and these must be recognized if intraoperative monitoring is to be successful. Frequency of stimulation, wakefulness, and anesthetic agents alter the wave-form and amplitude of the SEP. Using nitrous oxide, oxygen, meperidine (or morphine), and a muscle relaxant for anesthesia, and stimulating at frequencies of 1 or 2 per second, 11 patients with cervical or upper thoracic lesions have been monitored. There was no loss or diminution of an SEP and no patient was neurologically poorer afterwards. In 4 patients, the SEP "improved" soon after decompression. Clinical outcome, however, was not related to whether the SEP changed or remained the same. In total, 8 patients subsequently improved functionally and 3 did not.

Anesthesia↗