Clinical observations of the anatomy and function of the marginal mandibular nerve.

The objective of this study was to assess the anatomical variation of the marginal mandibular nerve, and evaluate the risk of nerve malfunction after neck dissection. The method involved clinical assessment of the anatomy and function of the marginal mandibular nerve in 133 neck dissections. When the neck was extended the nerve was displaced in an anterior and downward direction with the lowest point 1.25+/-0.7 cm below the mandible between the posterior and anterior facial veins. The nerve was >1cm below the lower border of the mandible in 54% of dissections. When the intent was to preserve the nerve, dysfunction was observed in 16 of 101 dissections (16%). The incidence of marginal mandibular nerve dysfunction following neck dissection is comparable to that observed following submandibular gland excision for benign disease. Placement of incisions 2 cm below the lower border of the mandible will put the nerve at risk in a significant number of patients.

Interstitial MR lymphangiography for the detection of sentinel lymph nodes.

BACKGROUND AND OBJECTIVES: The challenge for implementation of sentinel lymph node biopsy is to develop a reliable minimally invasive technique that identifies all possible sentinel nodes with high temporal and spatial resolution. This study evaluated the use of a magnetic resonance imaging (MRI) contrast agent (USPIO) for preoperative sentinel node detection. METHODS: Anesthetized pigs received interstitial or intradermal injections of ultra small superparamagnetic of iron oxide (USPIO) (0.2 or 5 mg Fe) in the L/R posterior tongue and stifles (knee) respectively. MRI was done before, during injection and at 0.25, 0.5, 1, 2, 4, 6, 24, and 48 hr after which isosulfan blue sentinel node mapping was done. RESULTS: In the tongue, both doses of USPIO identified the sentinel node in the early images. No additional nodes were detected by MR at 24 or 48 hr. In the hind limb, sentinel nodes identified on the early MR images were also identified by the isosulfan blue. In both locations, the higher dose also identified secondary nodes some of which were also identified by the isosulfan blue. All sentinel nodes that were identified by USPIO on MRI were noted to be stained brown at the time of dissection. CONCLUSIONS: Interstitial MR lymphangiography is a useful technique for the detection of sentinel lymph nodes. This method provides excellent simultaneous temporal and spatial resolution, is minimally invasive, and can be performed preoperatively.

Perioperative blood transfusion and albumin administration are independent risk factors for the development of postoperative infections after colorectal surgery.

OBJECTIVES: To determine whether transfused colorectal surgery patients were at increased risk for postoperative infections in a tertiary care teaching hospital and whether transfusion alone was the only significant risk factor. DESIGN: A retrospective study. SETTING: A single tertiary care teaching hospital. PATIENTS: All patients admitted to St. Boniface General Hospital, Winnipeg, for colorectal surgery during the period Apr. 1, 1995, through Mar. 31, 1996, were studied (N = 154). RESULTS: The overall infection rate was 17%: nontransfused patients, 13%, and transfused patients, 28% (p < 0.038). Patients who received albumin perioperatively had a significantly higher infection rate (38%) than those who did not (13%) (p < 0.001). Stepwise logistic regression analysis identified transfusion and albumin administration as the only independent risk factors for postoperative infection. CONCLUSION: Perioperative transfusion or albumin administration significantly increases the risk of postoperative infection in colorectal surgery patients.

The effect of thymic inoculation to induce tolerance of allogeneic thyroid grafts in the outbred rabbit.

Many studies have demonstrated that allograft tolerance can be achieved in inbred rats and mice following intrathymic injection of donor cells or antigen and treatment with antilymphocyte serum (ALS). In outbred dogs, xenografts, and inbred rat strains with major MHC antigen difference, tolerance has not similarly been induced. The focus of this study was to determine whether allogeneic thyroid graft tolerance could be achieved in outbred rabbits. In the experimental group (n = 5), recipients received an intrathymic injection of donor lymphocytes and a single treatment of ALS. Controls (n = 5) received intrathymic cell culture medium and ALS treatment. Donor-recipient allogenicity was monitored with mixed lymphocyte culture (MLC) over 18 weeks. Donor thyroid tissue was placed into recipient gluteal muscle fibres one week following the last MLC measurement. A third group of rabbits (n = 4) received thyroid autografts without any other treatment. There were no differences in MLC stimulation indices (SI) between the control and experimental group nor did MLC (SI) change within groups. All thyroid autografts survived the two week monitoring period and demonstrated normal appearing thyroid follicles on histologic examination. All thyroid allografts showed severe acute rejection reactions on biopsy within one week. Further studies using outbred animals to examine the role of thymic inoculation are required to determine whether similar techniques might be successful in the human.

Hippocampal volume in women victimized by childhood sexual abuse.

BACKGROUND: Several prior studies have found reduced hippocampal volume in victims of psychological trauma with post-traumatic stress disorder (PTSD). We were interested to determine if this finding was evident in women who were victimized by severe sexual abuse in childhood. METHODS: In this study, hippocampal volume was measured using quantitative magnetic resonance imaging (MRI) in 21 women who reported being severely sexually abused in childhood and 21 socio-demographically similar women without abuse histories. RESULTS: Women who reported sexual victimization in childhood had significantly reduced (5% smaller) left-sided hippocampal volume compared to the non-victimized women. Hippocampal volume was also smaller on the right side, but this failed to reach statistical significance. Left-sided hippocampal volume correlated highly (rs = -0.73) with dissociative symptom severity, but not with indices of explicit memory functioning. CONCLUSIONS: These findings, which are generally consistent with prior reports of reduced hippocampal volume in combat veterans with PTSD, suggest that diminished hippocampal size may be either a consequence of trauma exposure or a risk factor for the development of psychiatric complications following trauma exposure. The observed relationship between symptom severity and hippocampal volume suggests that mesial temporal lobe dysfunction may directly mediate certain aspects of PTSD and dissociative disorder symptomatology.

Report of survey: pregnancy outcomes in medical laboratory technologists.

A survey was published and distributed in the CSLT Bulletin. Completed surveys were returned anonymously by mail. Of the surveys returned (n = 2002), 16 were not usable due to incomplete information. Spontaneous abortion (SA) occurred in 19.9% of the total responders' pregnancies. Technologists not employed during pregnancy had a lower rate of SA (13.2%) compared to those working full-time (19.9%) (p < 0.001). Including all types of early (< 28 wk) pregnancy terminations (except induced abortion) the non-employed group had a 17% incidence of fetal loss compared to 23% in the group employed full-time (p < 0.001). The differences in SA rate could not be accounted for by mother's age at pregnancy nor previous obstetric history. The incidence of cesarean section was higher in the full-time employed group (16%) compared to the non-employed group of technologists (9.9%) (p < 0.001). There were 141 reported birth defects representing an overall incidence in responders of 4.8%, comparable to literature values for the general population (6.0%). The incidence of specific birth defects was not different in the working group.

Robotic system for i.v. antineoplastic drug preparation: description and preliminary evaluation under simulated conditions.

A robotic system for preparing doses of i.v. antineoplastic drugs is described, and measurements made with the system are compared for accuracy and reproducibility with those made by pharmacists and technicians. System hardware consists of a robotic arm, a 16-bit microcomputer, a bar-code reader, a voice synthesizer, and an electronic balance. The software includes a menu-driven main program, executable files for each robotic activity, and an interface to allow control to pass between the program and the files. The program has routines for matching the software to the hardware; for entering information about the patient, the name of the drug ordered, and the dose; for checking the dose; for selecting the number and size of the vials to be used; for specifying the manipulations of the robotic arm; for printing labels; and for maintaining records. The robot fills an order by getting and placing a vial, inserting a needle into it and withdrawing the drug, weighing the vial, agitating the container to dissolve its contents, reading a bar code, placing a syringe in a syringe manipulator, and getting an i.v. container and injecting the drug into it. Detection of any errors by a series of self-checks arrests execution of an order. No significant differences in accuracy and precision were found between the robotic system and humans performing the same tasks under simulated conditions. The robotic system required less time than humans and eliminated the possibility of direct human contact with the i.v. admixture. Under simulated conditions, a robotic system developed to assist in the preparation of i.v. antineoplastic drugs was as accurate as a manual system and was more time efficient.

Biophysical profile scoring in the management of the diabetic pregnancy.

Biophysical profile scoring was the principal technique of antepartum fetal surveillance in 238 well-controlled diabetic pregnancies. Fifty insulin-dependent diabetics had twice-weekly testing, and 188 gestational diabetics had weekly testing. Intervention was not pursued unless there were maternal or fetal complications. There were no stillbirths and three neonatal deaths, all resulting from congenital anomalies, giving a corrected perinatal mortality rate of 0. The incidence of abnormal biophysical profile scores, eight of 238 (3.3%) overall, was low, with no significant difference between types of diabetics. In those with an abnormal score, intervention was mandated; the cesarean section rate was 50% and the rate of intensive care nursery admissions was high. Of the 230 fetuses with a normal biophysical profile score, 200 (87%) were delivered at term with minimal maternal or neonatal morbidity. Amniocentesis for phospholipid profile was performed in only 33 cases (13.9%). Hyaline membrane disease was confined to five premature neonates (incidence 2.1%). We conclude that antepartum fetal surveillance using the biophysical profile score permits safe expectant management in the diabetic pregnancy, yielding significant clinical advantages to both mother and fetus.

Catecholamine responses to anesthetic induction with fentanyl and sufentanil.

In a randomized study, the authors examined the changes in plasma epinephrine and norepinephrine concentrations associated with induction of anesthesia and surgery in 33 patients with good ventricular function undergoing elective coronary artery surgery. After premedication with morphine and scopolamine, patients received either fentanyl, 100 micrograms/kg (n = 16), or sufentanil, 15 micrograms/kg, (n = 17), intravenously (IV), over 10 minutes to induce anesthesia. Metocurine, 0.42 mg/kg, IV, produced muscle relaxation. Arterial blood for plasma catecholamine determinations was drawn prior to induction, every two minutes throughout induction, one minute following endotracheal intubation, and one minute after sternotomy. Plasma epinephrine concentration was unchanged with either induction agent. Plasma norepinephrine concentration increased significantly after administration of either narcotic, peaked between six and ten minutes into induction, and returned to the preinduction value after intubation. Induction-related changes in arterial pressure and pulmonary capillary wedge pressure were significantly correlated with changes in the logarithm of plasma norepinephrine concentration. Similar degrees of endogenous norepinephrine release appear to accompany induction with equipotent doses of fentanyl and sufentanil in patients premedicated with morphine and scopolamine. Norepinephrine release may influence the hemodynamic response to induction with narcotics.

Ovine fetal urine production following maternal intravenous furosemide administration.

The response of the ovine fetus to maternal furosemide administration was studied in six chronically catheterized fetal lamb preparations. These studies indicate that in the chronic sheep model maternally administered diuretics do not augment fetal urine production. Additionally, passage of the drug from the maternal intravascular compartment to the fetal intravascular compartment could not be demonstrated. It is suggested that on the basis of these data, the results of the "Lasix challenge test" should be interpreted with caution when they are used to evaluate human fetal renal function.

Low-dose chenodeoxycholic acid for gallstone dissolution: a randomized trial in poor operative risk patients.

Thirty-five patients, with minimally symptomatic radiolucent gallstones in well opacifying gallbladders who had an unusually high risk of operative mortality, were randomized, double blind, into three groups: group 1, placebo; group 2,250 mg chenodeoycholic acid (CDC)/day; group 3,375 mg CDC/day. Every six months, oral cholecystograms and duodenal bile were obtained. Serum was collected at 0, 1, 2, 3, and 6 months, then at 6-month intervals. After 6 months, all placebo patients were assigned to 375 mg CDC/day (group 3b). No changes occurred in group 1 (N = 15). Gallstones dissolution: group 2, 2/10; 1 complete (C), 1 partial (P); group 3, 4/10, 1C, 3P; group 3b, 2/12, 2C. Lowest dose with complete dissolution was 3 mg/k/day (actual body wt). Lithogenic index of bile only improved with 375 mg/day (1.27 +/- 0.13 vs 0.88 +/- 0.05; mean +/- SDM), P < 0.01. No diarrhea or serum biochemical changes occurred; however, three patients died of their other medical illness. Low fixed doses of CDC, although not optimal, dissolved stones without toxicity in very ill patients.