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Biomedical subjects

M M Lewis

Publications and source records attributed to M M Lewis.

124 records · Page 7Linked to original sources
PubMed1971

Lack of involvement of fusimotor activation in movements of the foot produced by electrical stimulation of monkey cerebral cortex.

1. Contractions of the small muscles of the foot producing flexion and adduction of the hallux were elicited by brief trains of electrical stimulation of a motor point on the precentral gyrus of anaesthetized monkeys and these contractions were recorded myographically.2. The cortical stimulus intensities necessary to produce minimal muscle contractions were measured for different frequencies of stimulation at the cortical point, and the latency of the minimal muscle contraction was measured in each case.3. Section of all the relevant lumbar and sacral dorsal roots had no effect on the threshold stimulus currents necessary to produce minimal contractions or on the latencies of these responses. Hence, in the anaesthetized monkey, the power of the cortico-fusimotor activity stirred up by electrical stimulation of the cortex is inadequate to influence significantly the motor responses of the most accessible muscles.

Animals↗
PubMedDate not supplied

Contribution of peripheral input to length discrimination during use of a precision grip.

This study examined the ability of 63 subjects to discriminate a length difference, using a precision grip with the thumb and the index finger. To assess the relative contribution of different peripheral inputs associated with the discriminative ability of precision grip, three tasks were performed under each of three conditions-normal conditions; when vibratory stimuli were delivered to the forearm muscles; and when a local anesthetic was administered to the index finger. Under the first and second conditions, the length difference detected most frequently was 2.0 mm; in the third task, it was 3.0 mm. When a 100-Hz vibratory stimulus was applied to the forearm muscles, no difference in the threshold for length discrimination was observed for three of seven subjects. After injection of lidocaine into the metacarpophalangeal joint of the index finger, the threshold for length discrimination was significantly different for five of seven subjects. The detected length difference ranged from 1.0 to 4.0 mm. The authors question whether a single peripheral input is likely to make a major contribution to the complex perception that is used for discrimination tasks.

Adolescent↗
PubMedDate not supplied

Parents as passengers during pediatric transport.

INTRODUCTION: The transport environment presents a unique setting in which the feasibility, advantages, and disadvantages of passengers accompanying a patient must be assessed carefully. The purpose of this study was to describe the current practice of including parents as passengers during pediatric interfacility transport. METHODS: One-hundred-eighty-eight critical care transport programs in the United States responded to a voluntary mail survey, providing information about current policies, practices, and crew perceptions of the advantages and disadvantages of carrying parents as passengers. RESULTS: Extra seating for passengers was available in 96% of ambulances, 86% of fixed-wing aircraft, and 54% of helicopters used for pediatric transport. Parents traveled as passengers in all types of vehicles; most frequently in ambulances and fixed-wing aircraft. Twenty percent of helicopter programs allowed parent passengers on more than half of their pediatric transports in this vehicle. Advantages of parent passengers included emotional benefit for the parent and child, availability of parents for history and consent, good public relations, and having the parent present if the child dies. Disadvantages included potential parent anxiety, crew distraction, and space limitations. DISCUSSION: This study reflects the widely diverse policies, practices, and opinions relevant to this topic and confirms a need for further study.

Air Ambulances↗
PubMedDate not supplied

Sports tumors.

We present 36 patients who initially were thought to have sports-related injury but ultimately were diagnosed with a primary bone or soft tissue tumors or tumor-like condition. The awareness of this possibility in the individual with a sports-related complaint, who does not respond to standard management, may assist in earlier diagnosis and treatment of the suspected neoplasm.

Adolescent↗
PubMedDate not supplied

Malignant round cell tumor of bone with neural differentiation (neuroectodermal tumor).

A malignant round cell tumor primary in bone is reported in a young girl, showing histologically rosette formation and pseudoalveolar spaces. Vimentin, NSE, and S-100 were positive. Electron microscopy demonstrated abundant glycogen and neural features such as cell processes, microtubules, and occasional dense-core granules. Whether this neuroectodermal tumor represents a separate entity or is a variant of Ewing's sarcoma should wait for further experience, in the light of recent evidence suggesting that Ewing's sarcoma arises from primitive multipotential cells.

Adolescent↗
PubMedDate not supplied

Total femur and total knee replacement. A preliminary report.

Osteogenic sarcoma, a highly malignant tumor of bone, is generally treated by amputation. This is a report of 19 cases of excision of the entire femur because of skip areas which are occasionally seen. The femur usually has the lowest cure rate according to site of involvement. In total femur replacement, the whole bone is removed while the limb is saved. The operation consists of isolating the neurovascular bundle and removing the knee joint and femur including some surrounding normal tissue for margin of safety. The femur and knee replacements are made entirely of metal. The resultant extremity is weak, but functional. The patients can walk without support, but their gait is better using a cane and/or an ischial weight bearing brace.

Adolescent↗
PubMedDate not supplied

Simple bone cysts: true recurrence after complete obliteration.

A report of recurrent simple bone cysts in two cases--a seven-year-old and a six-year-old male--is presented. In each case curettage and cortical banked bone graft were performed. On follow-up, there was no clinical or radiographic evidence of further recurrence.

Bone Cysts↗
PubMedDate not supplied

An unusual case of cystic chondroblastoma of the patella.

An unusual case of chondroblastoma of the patella is presented in which the dominant feature was a hemorrhagic cyst. The chondroblastoma was located in a small gritty mass at one pole of the cyst, which could have easily been overlooked.

Adult↗