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Sertoli--Sertoli and Sertoli--germ-cell configurational relationships were studied using morphometric techniques and direct measurements as obtained from micrographs used to reconstruct a model of a rat stage V Sertoli cell. Regional areas of the Sertoli cell surface, which faced germ cells, other Sertoli cells, or noncellular structures, were expressed as relative surface area percentages; and the absolute surface areas for these regional areas were calculated. The surface areas of the reconstructed cell, in its unmagnified state, was found to be 12,163 micron2. Cell processes were enumerated and studied using morphometric techniques. The surface area of the reconstructed Sertoli cell facing germ cells and Sertoli cells was also determined. Five Sertoli cells showed extensive contact with the reconstructed cell at the level of the Sertoli--Sertoli junctional contact region. This contact region averaged 3.51 micron in width. The relative and absolute surface area of subsurface ectoplasmic specialization of the Sertoli cell that faced germ cells and other Sertoli cells was calculated, and the extent of penetration of step 17 spermatids into the Sertoli crypts was determined. Surface relationships of the reconstructed cell to cellular and noncellular elements were depicted on outline drawings of the Sertoli cell.
A morphological evaluation of intercellular bridges was undertaken during rat spermatogenesis. The dimensions and relationships of the bridges were shown to vary during different phases of spermatogenesis. Cellular divisions of spermatogonia and spermatocytes resulted in the partitioning of pre-existing bridges by complex structures termed bridge partitioning complexes, which are described in detail, as is the process whereby new bridges are formed. The structure of premeiotic bridges was generally consistent; however, during spermiogenesis, the structure of bridges and bridge contents were modified at specific phases of their development. The plasma membrane density associated with the cytoplasmic aspect of early step 1 spermatids separated into multiple dense bands that encircled the peripheral aspect of late step 1 spermatid bridges. By step 2 of spermiogenesis, these dense bands became associated with several cisternae of endoplasmic reticulum, which later coalesced into a single saccule that completely encircled the bridge structure by step 4. At steps 10-13 of spermiogenesis, the single saccule of endoplasmic reticulum vesiculated into many smaller cisternae. Also, filament-bounded densities (measuring 10-12 nm in diameter) appeared within the bridge channel. At step 17 of spermiogenesis, the filament-bounded densities were no longer apparent, but an anastomosing network of endoplasmic reticulum, often in the configuration of a sphere, occupied the entire central region of the bridge. In step 19 spermatids, the smooth endoplasmic reticulum within the bridge channel and the multiple cisternae lining the bridge density were gradually displaced. The subsurface density of bridges gradually lost its prominence. Some cytoplasmic lobes were connected by extremely narrow (approximately 22 nm) cytoplasmic channels. Similar-appearing channels were seen on the surface zone of cytoplasmic lobes or residual bodies, this observation suggesting that channels were sites of severence of bridges. Just prior to the separation or disengagement of the spermatid from the cytoplasmic lobe, selected bridges appeared to open to form large masses. After spermiation, residual bodies were not found joined by bridges; but from the size of some of the residual bodies, it was suspected that they were formed by coalescence of more than one cytoplasmic lobe. Freeze-fracture demonstrated few intramembranous particles on either the P or E face of the plasma membrane forming the bridge; this finding suggested bridge structures restricted free lateral movement of membrane constituents across the bridge.(ABSTRACT TRUNCATED AT 400 WORDS)
Abstract. Objective:To describe the clinical characteristics of a combination of midazolam and ketamine for procedural sedation and analgesia in adult emergency department (ED) patients. Methods: This was a prospective, observational trial, conducted in the ED of an urban level II trauma center. Patients Ն 18 years of age requiring procedural sedation and analgesia were eligible, and enrolled patients received 0.07 mg/kg of intravenous midazolam followed by 2 mg/kg of intravenous ketamine. Vital signs were recorded at regular intervals. The adequacy of sedation, adverse effects, patient satisfaction, and time to reach discharge alertness were determined. Descriptive statistics were calculated using statistical analysis software. Results: Seventy-seven patients were enrolled. Three were excluded due to protocol violations, three due to lack of documentation, and one due to subcutaneous infiltration of ketamine, leaving 70 patients for analysis. The average age was 31 years, and 41 (59%) were female. Indications for procedural sedation and analgesia included abscess incision and drainage (66%), fracture/joint reduction (26%), and other (8%). The mean dose of midazolam was 5.6 Ϯ 1.4 mg and the mean dose of ketamine was 159 Ϯ 42 mg. The mean time to achieve discharge criteria was 64 Ϯ 24 minutes. Five patients experienced mild emergence reactions, but there were no episodes of hallucinations, delirium, or other serious emergence reactions. Eighteen (25%) patients recalled dreaming while sedated; twelve (17%) were described as pleasant, two (3%) unpleasant, three (4%) both pleasant and unpleasant, and one (1%) neither pleasant nor unpleasant. There were four (6%) cases of respiratory compromise, two (3%) episodes of emesis, and one (1%) case of myoclonia. All of these were transient and did not result in a change in the patient's disposition. Only one (1%) patient indicated that she was not satisfied with the sedation regimen. Conclusions: The combination of midazolam and ketamine provides effective procedural sedation and analgesia in adult ED patients, and appears to be safe.
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