An inexpensive ex-vivo porcine laparoscopic Nissen fundoplication training model.

BACKGROUND: We recently implemented the use of an ex-vivo porcine model to teach residents the fundamentals of performing a laparoscopic Nissen fundoplication. METHODS: Residents were trained using intact porcine esophagus, stomach, and spleen placed in a standard video-trainer. They were later asked to complete a survey containing a course evaluation. RESULTS: Sixteen residents (R1-R4) completed the survey. They agreed that (1) the exercise was a valuable use of their limited time, (2) repeating the exercise will be of additional benefit, (3) it will improve their ability to perform or assist in an actual case in the OR, and (4) the surgical principles learned using the model will transfer to other laparoscopic cases. Significant subjective improvements were reported in resident comfort level in assisting in or performing a laparoscopic Nissen fundoplication. CONCLUSIONS: The use of an inexpensive ex-vivo porcine training model increases resident comfort level in performing a Nissen fundoplication in the operating room.     

Responsiveness to olfactory stimuli presented in sleep

Whether humans react to olfactory stimuli presented in sleep was assessed. Responses of ten participants (mean age = 22.8 years) were recorded to repeated three-minute periods of either air alone or to a peppermint odor (0.26 mg/liter) during stage 2 sleep. These responses included behavioral (awakening, microswitch closure), autonomic (heart rate, EMG, respiration), and central (EEG) components. An odor delivery system is described comprised of an aquarium pump, Teflon and TYGON tubing, oxygen mask, filtering, and air flow valves. The data indicate that humans react behaviorally, autonomically and centrally to olfactory stimuli presented while sleeping. Although the percentage of overall responsivity to olfactory stimuli was low, significant differences (ANOVA) in responsivity to odor periods vs. nonodor periods were found for microswitch closures, EEG, EMG, and heart rate. For these measures eight or more of the ten participants showed this pattern of differential responsivity during odor and nonodor periods (Sign test = p less than 0.05). A time-of-night effect was also observed in that responsivity tended to be greatest early in the night. The effect on responsivity of other durations, concentrations, and odors requires additional research.     

Choriocarcinoma with negative urinary and serum beta human chorionic gonadotropin (betaHCG)--a case report

This was a rare case where a patient presented clinically as a case of post abortal sepsis and ultrasound showing the picture of an intramural degenerating fibroid. Her serum and urine both were negative for beta human chorionic gonadotropin (betaHCG). Patient succumbed to choriocarcinoma 1 month later. Failure to detect urinary and serum betaHCG lead to maternal mortality due to the choriocarcinoma. The failure to detect, certain degradation products of HCG which may predominate in gestational trophoblastic neoplasia, by many common HCG testing kits lead to the error of diagnosis. Only 3 of the 7 common commercial serum HCG tests appropriately detects nicked HCG and its free betaHCG, DPC immulite assay, being the most sensitive method. Though of rare occurrence, this awareness is important for diagnosis and follow-up of gestational trophoblastic neoplasia and could have been life saving in our case.     

Behavioral control of abnormal breathing in sleep

Behavioral control of abnormal breathing in sleep was studied to determine if an intervention procedure could reduce apnea duration and also SaO ₂ (blood oxygen) desaturation levels. Sleep apnea patients (n=11) were instructed while awake that tones would be presented in sleep whenever an apnea event occurred. They were told to breathe deeply to the tones and were given practice in doing so. Intervention and nonintervention hours alternated across 2 nights following 2 baseline nights. As expected, during the intervention hours, the duration but not the frequency of apneic events was reduced. The procedure also resulted in higher SaO ₂ levels during the intervention hours. Daytime sleepiness was not greater following intervention but sleep staging effects were observed. The results are sufficiently promising to warrant additional research.This research was supported by NIH Grants 2 HL 27149-84 and HL 34125 entitled Behavioral Control of Respiration in Sleep.     

alpha(v)beta(3) Integrin in central nervous system tumors

alpha(v)beta(3) Is an integrin specifically expressed in endothelial cells of newly forming blood vessels. Integrin-mediated angiogenesis is hypothesized to play a central role in the development and the progression of central nervous system neoplasms. Accordingly, it is considered a potential target for antiangiogenic therapy. In the current study, we compare the expression of alpha(v)beta(3) in ependymomas, oligodendrogliomas, pilocytic astrocytomas, medulloblastomas, and vestibular schwannomas (acoustic neuromas). Samples of 5 tumors of each of the 5 tumor types were harvested surgically and frozen. After the pathological diagnosis was confirmed, immunohistochemistry was performed using an anti- alpha(v)beta(3) monoclonal antibody (LM609). The expression of alpha(v)beta(3) was assessed using a 4-tiered (0-3) grading scheme reflecting the percentage of positively staining vessels. All vestibular schwannomas demonstrated strong (grade 3) alpha(v)beta(3) expression. The expression was uniformly prominent in Antoni B regions of the tumors. Of 5 ependymomas, 4 demonstrated uniformly strong alpha(v)beta(3). Oligodendrogliomas, medulloblastomas, and pilocytic astrocytomas demonstrated more variable alpha(v)beta(3). alpha(v)beta(3) may contribute significantly to angiogenesis in vestibular schwannomas and ependymomas. Despite the high vascular density of oligodendrogliomas, pilocytic astrocytomas, and medulloblastomas, these tumors had variable moderate alpha(v)beta(3) expression. This discrepancy suggests temporal and/or regional variability in the angiogenesis in these types of tumor. This study provides the first demonstration of alpha(v)beta(3) expression in vestibular schwannomas, medulloblastomas, and pilocytic astrocytomas.     

Recurrent diffuse lipomatosis of the neck--a case report

Diffuse lipomatosis is a rare disorder of adipose tissue occurring in young people . It has a predilection for trunk and proximal extremities where it presents as poorly circumscribed overgrowth of fatty tissue. Definite diagnosis is established by histological examination of tumor. Though it attains extensive size and has a high tendency to recur, the clinical course is benign.