Anatomy of the cervicothoracic junction: a study of cadaveric dissection, cryomicrotomy, and magnetic resonance imaging

The morphologic characteristics of the cervicothoracic junction from C6 to T2 were examined. Gross dissection and cryomicrotomy was performed on 13 fresh cadavers. Four healthy volunteers underwent magnetic resonance imaging. Results indicated that vertebral body dimensions do not change appreciably, except for vertebral body heights and medial pedicular angulation, both of which increase from C6 to T2. Based on the findings of gross dissection and cryomicrotomy, the mediolateral width of the spinal canal was largest at C6 to accommodate the larger spinal cord at C6. The cross-sectional area ratios of the spinal cord to spinal canal were 1:2.3 at C6, 1:3.7 at C7, 1:4 at T1, and 1:3.7 at T2. The foraminal height and width were greater at C7-T1 and T1-T2 than at C6-C7. The thinnest lamina was at C7. The anatomy of the pedicles showed that the outer mediolateral diameter averaged 6.78 mm at C6, 7.5 mm at C7, 9.23 mm at T1, and 7.9 mm at T2. The superior-inferior diameter of the pedicle increased from 7.58 mm at C6 to 12.43 mm at T2. Medial angulations decreased from 44.5 at C6 to 23.35 at T2. The coronal angulation of the exiting nerve was 64.83 for C7, 79.83 for C8, and 90.33 for T1 nerve roots based on coronal magnetic resonance imaging. Finally, gross dissection during the anterior approach to the cervicothoracic junction revealed that this approach was extensible, allowing access to the anterior aspect of the cervicothoracic spine. Associated vital structures must be protected, such as the arch of aorta, common carotid artery, innominate vein, thoracic duct, recurrent laryngeal nerve, stellate ganglion, trachea, and esophagus.     

Antibiotic Administration in Patients Undergoing Common Surgical Procedures in a Community Teaching Hospital: The Chaos Continues

The influence of recently published guidelines by the Surgical Infection Society (SIS) on current surgical practice are not well documented. The appropriateness of antibiotic administration in a cohort of surgical patients undergoing elective and emergency surgery in a department of surgery in an urban, community-based, private, 560-bed teaching hospital was retrospectively reviewed. The following were the criteria defining administration as appropriate as modified from SIS guidelines: Prophylactic use: (1) started prior to operation; (2) spectrum appropriate to the specific operation; (3) duration ≤ 24 hours. Therapeutic use: (1) started prior to operation; (2) spectrum appropriate to pathology; (3) Duration ≤ 24 hours for contamination or “resectable” infection and ≤ 5 days for established infection in the absence of clinical evidence of persisting infection. Any switchover from an appropriate agent to another appropriate or inappropriate agent in the same patient in the absence of microbiologic or clinical indication was considered inappropriate administration. We reviewed the charts of 211 randomly selected patients who underwent elective (n= 132) or emergency (n= 79) procedures during 1996. The operations included gastrectomy (n= 22), appendectomy (n= 27), open (n= 5) or laparoscopic (n= 27) cholecystectomy, colectomy (n= 28), hysterectomy (n= 8), laparotomy for intestinal obstruction (n= 11), mastectomy (n= 26), and ventral hernia repair (n= 37). A total of 17 antibiotics were used for prophylaxis and 21 for therapy. In 156 patients (74%) the administration was considered inappropriate. Eight patients in the inappropriate group developed diarrhea (two cases of Clostridium difficile-induced colitis) compared to two cases of diarrhea in the appropriate group (nonsignificant). The average duration of administration after elective and emergency operations was 3.3 and 5.7 days, respectively. The total expense for excessive duration of administration was $18,533. Many surgeons are not familiar with the spectrum of antimicrobials and often do not distinguish between prophylactic and therapeutic administration. Antibiotic usage in current surgical practice is often inappropriate, excessive, and chaotic.     

Appropriate uses for spreadsheets, databases and statistical software for the analysis of dietary data

The article presents a new approach to analysis of dietary data, emphasizing the use of database systems, but including spreadsheets and statistical programs in the process. Spreadsheets are useful in dietary research for calculations required prior to entry of the data into a dietary analysis program, for investigation of the possible effects of changing dietary components and for graphical representation of data. A dietary program can provide output of data for a large number of subjects' diets into a database. Databases should be increasingly used in data analysis due to their powerful capacity to provide immediate answers to complex research questions. The database can be used to provide output directly in a form that can be pasted into a statistical program. Some knowledge of structured query language is required to construct appropriate queries of the database; an introduction to this language with some examples is given in this article.     

Characterization of chimeric prostacyclin/prostaglandin D(2) receptors

The functional activity of two chimeric mouse prostacyclin/prostaglandin D(2) (IP/DP) receptors, in which the carboxyl-terminal region of the IP receptor was progressively replaced by that of the DP receptor, was examined in Chinese hamster ovary (CHO) cells. The order of potency of prostaglandin D(2), prostaglandin E(2) and the IP receptor agonists cicaprost, iloprost and BMY 45778 (3-[4-(4, 5-diphenyl-2-oxazolyl)-5-oxazolyl]phenoxy]acetic acid) to stimulate cyclic AMP production was identical for the IP(N-VII)/DP(C), IP(N-V)/DP(VI-C) and wild-type IP receptors. IP(N-VII)/DP(C) receptor-expressing cells showed increases in basal adenylate cyclase activity, agonist potency and coupling efficiency. In addition, the intrinsic activity of the partial IP receptor agonists BMY 45778 and PGE(2) was significantly increased in IP(N-VII)/DP(C) receptor-expressing cells. Therefore, substitution of just the carboxyl-terminal tail of the IP receptor by that of the DP receptor appears to result in a chimeric IP/DP receptor with all the properties of a constitutively-active receptor.