Biomedical subjects
Publications and source records attributed to S B Young.
We report hematometra as a rare complication of cervical stenosis after a cone biopsy. Ultrasound and magnetic resonance imaging were very helpful in determining the diagnosis in conjunction with a physical examination.
We present a case report of a urethral diverticulum where magnetic resonance imaging suggested infected contents of the urethral diverticulum besides providing superb detail of periurethral anatomy. The critical clinical question was answered.
Vaginal fibromyomata are rare benign neoplasms; approximately 300 have been reported in the world literature. The clinical presentation is variable and the consistency of the mass on pelvic examination may be misleading. A mass may occur anywhere along the vaginal tube and is usually localized, mobile, nontender, and circumscribed. Its consistency, however, may range from solid to cystic. These lesions may be asymptomatic or may cause pain or urinary tract symptoms. Transabdominal and intravaginal sonography along with needle biopsy are valuable in making the preoperative diagnosis of a benign smooth-muscle tumor. Vaginal enucleation is the treatment of choice. Operative management should include evaluation of urethrovesical support and possible reconstruction, eg, pubourethral ligament plication.
Vincristine is a highly effective cell-cycle specific chemotherapeutic agent used in the treatment of most pediatric malignancies. The major dose-limiting side effect of this drug is neurotoxicity, which can present in the form of peripheral, autonomic, or cranial nerve deficits. Conditions such as liver dysfunction can increase the risk for vincristine neurotoxicity. The only treatment for severe toxicity is to decrease the drug dose or to discontinue the drug. Many of the symptoms of neurotoxicity are subjective and therefore adequate assessment is often difficult. Baseline data is obtained before starting vincristine and with each subsequent clinic visit so that the appropriate drug dose can be determined to maximize tumor response with the fewest side effects. Nursing interventions are directed at symptom management. Patient-family education centers on relating informing of the potential and symptoms of neurotoxicity, with an emphasis on safety precautions.
A proband with a lethal variant of osteogenesis imperfecta (OI) has been shown to have, in one allele in a gene for type I procollagen (COL1A1), a single base mutation that converted the codon for alpha 1-glycine 904 to a codon for cysteine. The mutation caused the synthesis of type I procollagen that was posttranslationally overmodified, secreted at a decreased rate, and had a decreased thermal stability. The results here demonstrate that the proband's mother had the same single base mutation as the proband. The mother had no fractures and no signs of OI except for short stature, slightly blue sclerae, and mild frontal bossing. As a child, however, she had the triangular facies frequently seen in many patients with OI. On repeated subculturing, the proband's fibroblasts grew more slowly than the mother's, but they continued to synthesize large amounts of the mutated procollagen in passages 7-14. In contrast, the mother's fibroblasts synthesized decreasing amounts of the mutated procollagen after passage 11. Also, the relative amount of the mutated allele in the mother's fibroblasts decreased with passage number. In addition, the ratio of the mutated allele to the normal allele in leukocyte DNA from the mother was half the value in fibroblast DNA from the proband. The simplest interpretation of the data is that the mother was mildly affected because she was a mosaic for the mutation that produced a lethal phenotype in one of her three children.
The purpose of the present study was to examine the afferent mechanisms for phasic hypoglossal and phrenic responses to airflow changes in the upper airway (UAW). An isolated UAW was produced in decerebrate, unanesthetized, vagotomized, paralyzed and ventilated cats. Activities of both the hypoglossal and phrenic nerves were monitored at hyperoxic (FETCO2 greater than 0.80) normocapnia (FETCO2 = 0.04-0.05). As inspiratory airflow passing through the UAW, hypoglossal activity enhanced significantly while phrenic discharge reduced (p less than 0.01). After bilateral denervation of the superior laryngeal nerve (SLN), enhancements of hypoglossal activity in response to the same level of airflow were much lower whereas reduce in phrenic discharge was eliminated. Combined with sectioning of the glossopharyngeal nerve (GPN), augmentation of hypoglossal response to airflow was even higher. This increase in hypoglossal activity with airflow changes was not discerned when the trigeminal ganglion (TGG) was further destroyed. These results suggest that airflow changes in the UAW, which was sensed by the receptors in the SLN, GPN, and TGG, produce an increase in hypoglossal discharge and a decrease in phrenic burst. Increase in hypoglossal activity in response to airflow change in the UAW may relate to keeping a patent UAW.
To determine whether intraumbilical oxytocin would shorten the third stage of labor, we enrolled 50 normal parturients into a randomized, double-blind protocol. Either 10 U of oxytocin diluted to 20 mL in normal saline (25 subjects) or 20 mL of normal saline alone (25 subjects) was injected into the placental circulation within one minute after cord clamping. The mean (+/- SD) duration of the third stage was 4.1 +/- 2.0 minutes in saline-treated subjects and 4.6 +/- 3.4 minutes in those treated with oxytocin. Intraumbilical oxytocin was not effective in shortening the normal third stage of labor.
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Stereology was used to investigate the changes in ultrastructure of smooth muscle cells during the formation of an experimental intimal thickening induced by injury with an inflated balloon catheter. The volume density of myofilaments in the cell cytoplasm was measured in smooth muscle cell-lined areas (which are freely permeable to Evans blue dye and, hence, stain blue) and in re-endothelialized areas (which remain white after injection of Evans blue) of the rabbit carotid artery. Two weeks after injury, the volume densities of myofilaments in the intimal smooth muscle cells in both white and blue areas were significantly less than that for control medial smooth muscle (67.9% +/- 3.6%; mean +/- SE), being 38.8% +/- 1.0% and 35.9 +/- 3.3%, respectively. By 6 weeks after injury, the volume density had increased significantly in both white (55.1% +/- 3.4%) and blue areas (53.5% +/- 3.0%), and these values did not change significantly by 18 weeks. The volume density of myofilaments in the luminal (lining) smooth muscle cells in the blue areas was significantly less than that of control medial cells and remained low (26.7% +/- 2.1%) up to 18 weeks after injury. The initial balloon-induced injury caused considerable damage to the smooth muscle cells in the media, and the remaining medial cells underwent similar changes in ultrastructure to the cells in the neointima. At 2 weeks, the cells had a low volume density of myofilaments (44.9% +/- 2.4%), which returned to a level not significantly different from the control artery by 6 weeks after injury. There were no differences in the estimates of the volume density of myofilaments between the inner and outer media of the injured arteries. These findings suggest that, after injury produced by a balloon catheter, the smooth muscle cells in both the media and the resultant intimal thickening undergo a reversible change in ultrastructure.