Biomedical subjects
Publications and source records attributed to E Schultz.
Neodymium:YAG and holmium:YAG lasers were used to remove intraluminal sutures from three patients. In two, the suture was in the bladder and had served as a nidus for stone formation. In the other, the suture was in the ureter. An in vitro study showed that the Nd:YAG laser could divide all types of suture readily, whereas the Ho:YAG laser could divide all materials except Gortex. These cases illustrate another application for lasers.
OBJECTIVE: Botulinum toxin (BT) is a currently used treatment for spasmodic dysphonia (SD) and other related focal dystonias. The goal of this study is to provide a basis for using the rat larynx to objectively assess physiological and histological effects of BT. STUDY DESIGN: Dosages and volumes of BT injection were varied and three physiological parameters were measured. These measures included: optical density of PAS-stained laryngeal muscle after electrical stimulation, which is an indirect measure of denervation, spontaneous laryngeal muscle activity, and laryngeal movement. METHODS: A new microlaryngoscopic technique was developed, which made it possible to observe and manipulate the rat larynx endoscopically. Laryngeal movement and electromyographic (EMG) measures were made prior to injection and 3 days following BT injections of various dosages and volumes. Optical density measures were made 3 days after injection. RESULTS: Significant reductions in vocal fold motion and spontaneous laryngeal muscle activity as a function of increased BT dosage were observed. In addition, the optical density of PAS-stained laryngeal muscle after electrical stimulation was increased following BT injection. Significant volume effects in optical density were observed in the lateral thyroarytenoid and lateral cricoarytenoid muscles on the contralateral side. CONCLUSIONS: The rat laryngeal model is suitable for assessing BT effects. In addition, the three physiological variables provided useful and reliable measures of laryngeal function. It is the authors' intention to use the rat laryngeal model to further examine the physiological and histological effects of BT with the goal of developing new methods for the treatment of patients with SD and other focal dystonias.
OBJECTIVES: To characterize the acute and chronic cellular effects of botulinum toxin (BT) injection into rat laryngeal muscles. A complete characterization of these effects is important because patients with focal dystonias of the head and neck are commonly treated with BT injection. Further, potential muscular changes in the larynx must be carefully delineated owing to the critical phonatory and airway protective functions of these muscles. STUDY DESIGN: The acute and chronic cellular effects of BT injection were studied using 5'-bromo 2'-deoxyuridine (BrdU) following single and repeated BT injection into rat laryngeal muscles. BrdU is incorporated into mitotically active nuclei such that changes in cell proliferative behavior following BT injection can be monitored. RESULTS: Increased mitotic activity was detected in the tissue samples studied following BT injection. Differences in the times of the peak distribution of BrdU-labeled cells in each laryngeal muscle were observed. This may be related to the diffusion effects of BT. Prolonged muscle fiber changes, including splitting, were also observed as the result of repeated BT injection. CONCLUSIONS: The results of this study suggest that BT may induce a proliferative response in muscle tissue.
The relationship between myogenin or MyoD expression and hypertrophy of the rat soleus produced either by clenbuterol and 3,3', 5-triiodo-L-thyronine (CT) treatment or by surgical overload was examined. Mature female rats were subjected to surgical overload of the right soleus with the left soleus serving as a control. Another group received the same surgical treatment but were administered CT. Soleus muscles were harvested 4 wk after surgical overload and weighed. Myosin heavy chain isoforms were separated by using polyacrylamide gel electrophoresis while myogenin and MyoD expression were evaluated by Northern analysis. CT and functional overload increased soleus muscle weight. CT treatment induced the appearance of the fast type IIX myosin heavy chain isoform, depressed myogenin expression, and induced MyoD expression. However, functional overload did not alter myogenin or MyoD expression in CT-treated or non-CT-treated rats. Thus pharmacologically and surgically induced hypertrophy have differing effects on myogenin and MyoD expression, because their levels were associated with changes in myosin heavy chain composition (especially type IIX) rather than changes in muscle mass.
OBJECTIVE: We describe our experience using sonography to evaluate the patella and patellofemoral joint in three children with congenital abnormalities of the extensor mechanism of the lower extremity. CONCLUSION: Sonography can be used to evaluate the extensor mechanism and unossified patella in young children. Advantages of sonography over MR imaging are no need for sedation, speed of examination and ability to compare with the contralateral knee, low cost, and the sonographer's ability to dynamically evaluate the extensor mechanism.
A study was conducted to determine the frequency of, and risk factors for, drug-resistant pulmonary tuberculosis (TB) among Baja California (BC) and San Diego County (SDC) residents. Another purpose was to document the amount of contact between pulmonary TB patients and residents of the opposite side of the the border. During the period from February 1995 to May 1996, pulmonary TB patients from BC (n = 427) and SDC (n = 331) were evaluated with cultures, drug susceptibility tests, and questionnaires. Drug resistance was found in 41% of the BC Mycobacterium tuberculosis complex (MTB) isolates and 20% of the SDC isolates. Resistance to both isoniazid (INH) and rifampin (RIF) varied from 1% of isolates from SDC patients to 17% of isolates from BC patients. Patients with a history of previous treatment had increased odds of drug-resistant disease. Older BC patients were more likely to have INH- or RIF-resistant TB. Although 42% of Tijuana TB patients reported recent contact with residents from SDC, travel to Mexico and contact with residents from Mexico were not significant risk factors for drug-resistant TB among SDC residents. However, the demonstrated contact between TB patients and residents on opposite sides of the border indicates the importance of coordinating efforts internationally to control TB.
Scapulothoracic dissociation is an uncommon and devastating traumatic injury. A review of 72 cases in the English literature shows that a broad range of musculoskeletal and neurovascular injuries resulting from blunt trauma have been classified as scapulothoracic dissociation since the term was first used in 1984. A review of the current clinical signs and radiographic findings that define scapulothoracic dissociation, as well as a brief description of treatment options and outcomes, is presented.
Tumors developing in association with metallic implants are being reported with increasing frequency in the orthopedic literature. The authors report the tenth case of malignant fibrous histiocytoma associated with a total hip replacement. The diagnosis was made during an evaluation for rapid radiographic osteolysis surrounding the femoral component detected less than 1 year after revision of a hemiarthroplasty to a total hip replacement. The short latency period and aggressiveness of this tumor mimicking rapid osteolysis prompted a review of the literature, etiology and significance of implant-associated malignant fibrous histiocytoma.
Scapular fractures in children are rare injuries. The indications for the surgical treatment of glenoid fossa fractures in children are not well defined. We report on an eight-year-old child with a displaced glenoid fossa fracture requiring open reduction and internal fixation. A review of the literature and indications for the operative management of glenoid fossa fractures in children are discussed.
The role of satellite cells and DNA unit size in determining skeletal muscle growth was studied after mitotic activity was inhibited in the left pectoralis thoracicus of 2-wk-old tom turkeys by means of a 25-Gy dose of irradiation. Toms were killed and muscle weights were obtained 1 (n = 5), 4 (n = 6), 7 (n = 6), and 15 (n = 4) wk after irradiation. Satellite cell mitotic activity and DNA unit size were determined using enzymatically isolated myofiber segments and image analysis. Irradiated and nonirradiated muscle weights increased (P < 0.01) between all ages examined, but irradiated muscle weights were significantly (P < 0.01) lower than nonirradiated muscle weights at 4, 7, and 15 wk after irradiation. Satellite cell mitotic activity was lower (P < 0.01) in irradiated than in nonirradiated muscles at 1 and 4 wk after irradiation and resulted in a significant reduction (P < 0.05) in the number of myofiber nuclei per millimeter at 4 and 7 wk after irradiation. Satellite cell mitotic activity was higher (P < 0.05) in irradiated than in nonirradiated muscles at 7 wk after irradiation, but at 15 wk after irradiation it had fallen to low levels in both muscles. There was no significant (P > 0.10) difference in DNA unit size between muscles at any time, but there was an age-related increase (P < 0.01) for both muscles. Irradiation reduced muscle growth through a transient reduction in myonuclear production at a critical time (3-6 wk of age) in posthatch skeletal muscle development. The age-related increase in DNA unit size was not accelerated to compensate for the reduction in myonuclear accretion. Thus it appears that muscle growth potential is governed mostly by myonuclear accretion and to a lesser extent by DNA unit size.
This pilot study was designed to determine if the interval between repeated botulinum toxin injections influenced physiologic and histologic effects on laryngeal muscles in a rat model. The physiologic measurements included digitized videomicroscopic recording of vocal fold movement and electromyography. The histologic measurements included muscle fiber size and digitized optical density of laryngeal muscles after glycogen depletion by electrical stimulation. The results demonstrated that the effect of timing of the second injection was strongly correlated to laryngeal changes. Most notable were results in the subjects that underwent injections 6 weeks apart. We hypothesize that these findings might be related to terminal axonal sprouting with reinnervation. The results from this study help confirm and expand the validity of using the rat laryngeal model to understand the effect of botulinum toxin. Moreover, we believe that the data might be extrapolated to prove useful in predicting human responses to botulinum toxin treatment for functional dystonias such as spasmodic dysphonia.
Giant synovial cysts in patients with rheumatoid arthritis are well-recognized soft-tissue masses adjacent to the knee. Cases involving the elbow, hip, and other synovial joints have been reported as well. Regardless of location, these expanding, space-occupying lesions usually present with nonspecific symptoms of swelling and pain. Less commonly, the original presentation may be related to the secondary effects of the cyst on nearby anatomic structures. We present a case of a giant synovial cyst originating posteriorly in the knee, which, rather than dissecting distally into the calf, dissected proximally into the posterior soft tissue of the thigh in a patient with long-standing rheumatoid arthritis.
The cell cycle time of satellite cells in growing rats was determined to be approximately 32 hr, with an S-phase of 14 hr. The estimated cycle time was the same for satellite cells in both oxidative soleus and glycolytic EDL muscles and is consistent with the rate at which myonuclei are produced during growth. Continuous infusion of bromodeoxyuridine (BrdU) was used to determine if all satellite cells had the same cycle time in vivo. Approximately 80% of the satellite cell population was readily labeled over the first 5 days of continuous infusion. Remaining satellite cells accumulated label at a much slower rate and were still not completely saturated after an additional 9 days of infusion. Only a small portion of the cells labeled with BrdU during the first 5 days could be labeled with a second label ([3H]thymidine) during tandem continuous infusion experiments, suggesting that they pass through a limited number of mitotic divisions prior to fusion. These results suggest that satellite cells in growing oxidative and glycolytic skeletal muscles can be subdivided into two distinct compartments. About 80% divide with a 32-hr cell cycle duration and are responsible chiefly for providing myonuclei to growing fibers. The remaining 20% of the cells divide more slowly, probably because the cells enter a G(0)-phase between mitotic divisions. These reserve cells, through asymmetric divisions, may generate the myonuclei-producing satellite cell population. Proliferative potential for regeneration and adaptive responses is likely located in this reserve population.
A comprehensive drug screening procedure for detecting drugs in the blood samples of car drivers suspected of driving under the influence of drugs, is presented. Amphetamines, cannabinoids, opioids, cocaine and benzodiazepines were screened by an immunological EMIT ETS system after acetone precipitation. Gas chromatographic methods were used to screen and quantitate basic, neutral and acidic drugs. The free amino groups of basic drugs were derivatized with heptafluorobutyric anhydride. Analysis was performed by a dual channel gas chromatograph combined with a nitrogen phosphorus and an electron capture detector. Phenyltrimethylammonium hydroxide was used as a methylathing agent for acidic substances before analysis with a gas chromatograph connected to a nitrogen phosphorus detector. A gas chromatograph/mass spectrometry was used as a common confirmation method. Tetrahydrocannabinol was quantitated after bis(trimethylsilyl)trifluoroacetamide derivatization, opiates after pentafluoropropionic anhydride derivatization and benzoylecgonine after pentafluoropropionic anhydride and pentafluoropropanol derivatization. Excluding benzodiazepines, which were confirmed with a gas chromatograph connected to a nitrogen phosphorus and an electron capture detector, the other basic drugs as well as the acidic drugs were confirmed after the same derivatization procedures as in the screening methods. Alcohols were quantitated in triplicate by gas chromatography using three different kinds of columns. Although urine is the most important specimen for screening abused drugs, it has only limited use in forensic toxicology. The described system is most useful for analyzing a wide range of substances, including illicit drugs, benzodiazepines, barbiturates, antidepressants and phenothiazenes in forensic samples when urine is not available.
The majority of skeletal lesions affecting the patella are benign and include entities such as chondroblastoma, giant cell tumor, osteomyelitis, and gout. Malignant processes involving the patella are distinctly unusual. Isolated occurrences of plasmacytoma, osteosarcoma, hemangiosarcoma, and metastatic disease have been reported. Malignant lymphoma involving the patella is extremely uncommon, although lymphomatous infiltration of the skeletal system is not a rare event, especially with the histiocytic lymphoma. The most frequent radiologic manifestations of skeletal lymphoma include osteolytic lesions with ill-defined margins involving the metaphysis of the long bones of the lower extremities. Involvement of the short tubular and flat bones, as well as the axial skeleton, occurs less commonly. The prognosis for lymphoma involving the skeleton is poor.
The effect of in vivo and in vitro irradiation on subsequent satellite cell growth, in vitro, was investigated to ascertain the ability of a 25 Gy dose to inhibit satellite cell proliferation. Satellite cells were isolated from the left (irradiated) and right (non-irradiated) Pectoralis thoracicus of two-week-old tom turkeys 16 h (n=3) and seven weeks (n=2) after the left Pectoralis thoracicus had been irradiated (25 Gy). Satellite cells isolated from the irradiated and non-irradiated muscles exhibited similar (P>0.10) in vitro proliferation indicating that a population of satellite cells survived an in vivo dose of 25 Gy. In additional experiments, satellite cell cultures derived from tom turkey Pectoralis thoracicus were irradiated (25 Gy) in vitro. The number of satellite cells did not (P>0.05) increase in irradiated cultures for 134 h following irradiation, while satellite cells in non-irradiated cultures proliferated (P<0.05) over this time. At later time periods, satellite cell number increased (P<0.05) in irradiated cultures indicating that a population of satellite cells survived irradiation. The results of these in vitro experiments suggest that a 25 Gy dose of irradiation does not abolish satellite cell divisions in the turkey Pectoralis thoracicus.
A double fluorescence staining protocol was developed to facilitate computer based image analysis. Myofibers from experimentally treated (irradiated) and control growing turkey skeletal muscle were labeled with the anti-myosin antibody MF-20 and detected using fluorescein-5-isothiocyanate (FITC). Extracellular material was stained with concanavalin A (ConA)-Texas red. The cross-sectional area of the myofibers was determined by calculating the number of pixels (0.83 mu m(2)) overlying each myofiber after subtracting the ConA-Texas red image from the MF-20-FITC image for each region of interest. As expected, myofibers in the irradiated muscle were smaller (P < 0.05) than those in the non-irradiated muscle. This double fluorescence staining protocol combined with image analysis is accurate and less labor-intensive than classical procedures for determining the cross-sectional area of myofibers.
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