Endoscopic surgery teleconferencing

Modern telecommunication allowing the transmission of digitalized voice and images through telephone lines has expanded to medicine. The Integrated Digital Network System (ISDN) can be used to transmit 128 kbit/sec (ISDN-2) to 2 Mbit/sec (ISDN-30). Together with smart compression techniques a teleconferencing system can be implemented to transmit images of an endoscopic operation. In this paper 2 such experiments are described. In the first experiment a laparoscopic cholecystectomy performed in the Netherlands is followed at the same time by surgeons in Hawaii through ISDN-2 lines. In the second experiment a laparoscopic hernia repair was followed in Orlando during a congress using ISDN-6 lines. The images sent over the ISDN-2 lines are rather blurry with rapid movement. The images over the ISDN-6 lines were more acceptable. Data compression and decompression results in a time delay of approximately 1 second, which seems not disturbing during the connection. The cost of communication is comparable to telephone communication, which makes this form of telecommunication feasible in surgical practice.

Local action of trophoblast interferons in suppression of the development of oxytocin and oestradiol receptors in ovine endometrium

Luteolysis in sheep is associated with uterine secretion of pulses of prostaglandin F2 alpha (PGF2 alpha) due to the action of luteal oxytocin on endometrial oxytocin receptors. For pregnancy to become established inhibition of oxytocin receptors is important as an antiluteolytic mechanism. The maternal recognition of pregnancy in cattle and sheep involves production, by the trophoblast, of a type 1 interferon (IFN-tau) that suppresses uterine development of oxytocin receptors and the generation of luteolytic episodes of PGF2 alpha. The action of IFN-tau in surgically prepared unilaterally pregnant ewes was investigated. Finn-Dorset ewes were anaesthetized on day 6 or 7 of the oestrous cycle and one uterine horn was surgically isolated at the uterine bifurcation from the body of the uterus. Ewes were mated at the subsequent oestrus either by a fertile or by a vasectomized ram and killed on day 13 or 16 after mating. On day 16, in the non-pregnant ewes, there was no measurable uterine IFN-tau but there were high concentrations of oxytocin receptors in both horns. In the pregnant ewes on day 16 after mating, the oxytocin receptor concentration was 45 +/- 11 fmol mg-1 protein in the pregnant horn and 585 +/- 131 fmol mg-1 in the non-pregnant horn. Antiviral activity was 5.8 x 10(7) +/- 5.2 x 10(7) U ml-1 in the pregnant horn and 2.9 x 10(3) +/- 1.2 x 10(3) U ml-1 in the non-pregnant horn. Thus, 16 days after mating, the pregnant horn exhibited high antiviral activity but oxytocin receptors were suppressed, while in the same endocrine environment (characteristic of pregnancy) there were low IFN-tau and high oxytocin receptor concentrations in the isolated horn equivalent to those expected at the onset of luteolysis. In situ hybridization to ovine mRNA encoding the oxytocin receptor and autoradiographic studies using the 125I-labelled oxytocin antagonist d(CH2)5[Tyr(Me)2,Thr4,Tyr-NH2(9)]-vasotocin both showed that the large amount of oxytocin receptor message and binding sites in the endometrium of the isolated horn were localized in the luminal epithelium. Immunocytochemical studies showed that there was a suppression of oestradiol receptors in the pregnant horn but high concentrations equivalent to those at oestrus were present in the isolated horn. The content of progesterone receptors was low in the stromal tissue only in both horns, a pattern of localization similar to that seen in the late luteal phase and in early pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)

Teleconferencing bridges two oceans and shrinks the surgical world

Endoscopic surgery has led to changes in surgical practice which may rival the introduction of anesthesia and antibiotics in significance. As a result, an exciting synergy has rapidly emerged between technology and clinical practice. However, questions of training, credentialing, and patient safety have been raised as traditional procedures have been adapted to the minimally invasive approach and new ones are described. Many surgeons have been reluctant to venture beyond laparoscopic cholecystectomy. Halting first efforts at advanced procedures may prolong operative times, increase risk, and raise costs. Older methods of surgical education are not adequate to meet the current need (Fig. 1).

Laparoscopic or open inguinal herniorrhaphy? A randomized prospective trial

OBJECTIVE

To determine whether transabdominal preperitoneal laparoscopic hernia repair can equal or surpass an established open method at an acceptable cost.

DESIGN

A randomized, prospective comparison with a follow-up of 7 to 18 months (median, 10 months; planned, 5 years).

SETTING

Health maintenance organization hospital.

PATIENTS

One hundred patients between 20 and 70 years of age were randomized. No patient withdrew from the study after randomization.

INTERVENTIONS

Transabdominal preperitoneal laparoscopic and open tension-free repairs using a polypropylene mesh.

MAIN OUTCOME MEASURES

Operative and discharge times, costs, recovery, and morbidity. "Return to work" was supplemented by a performance assessment using a panel of exercises.

RESULTS

Operative and hospitalization times were not significantly different between the two types of repair. Patients with laparoscopic unilateral repairs returned to work faster (9 vs 17 days). At 1 week postoperatively, performance of straight-leg raises correlated well with time to return to work for patients with strenuous jobs. The laparoscopic repair was more expensive than the open approach ($3093 vs $2494).

CONCLUSIONS

Laparoscopic transabdominal preperitoneal hernia repair can be accomplished with operative and hospitalization times and a short-term recurrence rate similar to those of an established open technique. Perioperative exercise testing may be an important adjunct to return to work in the comparison of methods.

The direct influence of the embryo on uterine PGF2 alpha and PGE2 production in sheep

In unilateral pregnant ewes, obtained by surgically transecting one uterine horn to isolate it from the rest of the pregnant uterus, the isolated horn develops endometrial oxytocin receptors by day 16 despite being in a hormonal environment equivalent of that of a pregnant ewe. This study examines uterine prostaglandin production in these animals. On day 16 of pregnancy, ewes were anaesthetized and a uterine vein draining each horn and the jugular vein cannulated. Venous blood samples were taken at 10 min intervals for 1 h before and 1 h after an i.v. injection of oxytocin (1 microgram). Uterine vein samples were assayed for PGF2 alpha and PGE2 and jugular blood samples assayed for 13,14-dihydro,15-keto-PGF2 alpha. All ewes showed high plasma concentrations of 13,14-dihydro,15-keto-PGF2 alpha after the oxytocin injection. PGF2 alpha increased in the uterine vein draining the nonpregnant transected horn of a unilaterally pregnant ewe following oxytocin treatment, whereas there was no increase in concentration in plasma draining the pregnant horn. Basal plasma PGF2 alpha concentrations from the uterine vein draining the pregnant horn were significantly higher than concentrations obtained from the uterine vein of the transected horn while PGE2 concentrations did not vary between the two horns. After oxytocin injection, there was a significant increase in plasma PGE2 concentration in venous blood collected from both sides.(ABSTRACT TRUNCATED AT 250 WORDS)

Ultrasonic dissection

Following its development for cataract surgery, and gaining widespread use in neurosurgery and liver resection, ultrasonic dissection has been adapted for laparoscopic use. The turbulence, heat, and pressure generated by imploding bubbles disrupts tissues high in water content. This phenomenon is called cavitation and is the principal means by which ultrasonic dissection is accomplished. A randomized, prospective trial demonstrated the utility of the device for laparoscopic cholecystectomy. It was particularly effective in the presence of acute periportal inflammation or fat. Additional experience with a wide range of laparoscopic procedures is being accumulated by several investigators around the world. The laparoscopic use of ultrasonic dissection will be most valuable whenever selective, precise, and, therefore, safe dissection is desired.

Insensitivity of dispersed caprine luteal cells to β-adrenergic agonists and other putative transmitter substances

Adrenaline (10(-6)-10(-4)M), serotonin (10(-6)-10(-4)M), and several other potential steroidogenic agonists failed to enhance either basal or LH-stimulated progesterone production from dispersed caprine luteal cells from Day 10 of the estrous cycle. The caprine corpus luteum (CL) would appear to be more refractory to exogenous stimulation than either the ovine or bovine CL.

Pulsatile release of oxytocin after suppression of prostaglandin synthesis in hysterectomised ewes

On days 13 and 14 after oestrus (day 0) oxytocin and 13,14-dihydro-15-keto-prostaglandin (PG)F2 alpha (PGFM) concentrations were measured in jugular plasma of hysterectomised sheep with or without systemic treatment with the PG cyclo-oxygenase inhibitor indomethacin (4 mg kg-1 three times a day on days 12, 13 and 14 subcutaneously. Pulsatile increases of oxytocin were observed in both untreated and treated sheep with mean (+/- SD) peak heights of 18.4 +/- 9.6 pg ml-1 (n = 11) and 23.5 +/- 9.4 pg ml-1 (n = 8), respectively; these means were not significantly different. Plasma concentrations of PGFM remained consistently low in both groups (under 100 pg ml-1) with no significant peaks observed. The data suggest that PGF2 alpha may not be the only stimulus for the release of luteal oxytocin, or that there may be a contribution by the posterior pituitary to oxytocin secretion during the luteal phase of the ovine oestrous cycle.

Direct stimulation of bovine ovarian progesterone secretion by low concentrations of alpha-interferon

The ruminant conceptus secretes proteins during early pregnancy which maintain the corpus luteum. These trophoblast proteins are related to the alpha II-interferons and prevent luteolysis indirectly by disrupting the secretion of endometrial prostaglandin. Although trophoblast interferons appear to be largely confined to the uterine lumen, it remains possible that they also act peripherally. This report describes in vitro studies which suggest that interferon may influence hormone secretion by the ovary directly. The study employed i) a well defined serum-free culture model in which bovine granulosa cells secrete the luteal hormones progesterone and oxytocin, and ii) serum-free and serum-supplemented cultures of cells from early CL. Dose-response experiments were performed using bovine recombinant alpha-interferon (brIFN). Progesterone and oxytocin secretions were measured over 4-5 days of culture and DNA content was also determined. Low concentrations of brIFN (10(-15) mol/l to 10(-11) mol/l) stimulated progesterone secretion by granulosa cells by up to three fold, without significantly affecting oxytocin concentrations or culture DNA content. Concentrations of 10(-10) mol/l to 10(-1) mol/l suppressed progesterone secretion in a log dose-related manner (r = 0.97) with evidence of toxicity (lower oxytocin concentrations and significantly reduced DNA compared with controls). Progesterone secretion by luteal cells in serum-free culture was stimulated in the presence of 10(-15) mol/l brIFN, whilst high concentrations again caused inhibition. The data show that ovarian cells can respond directly to low concentrations of interferon-like proteins.(ABSTRACT TRUNCATED AT 250 WORDS)

The ultrasonic dissector facilitates laparoscopic cholecystectomy

The ultrasonic dissector disrupts tissues in proportion to their fluid content by ultrasonically induced cavitational forces. Since sturdy tissues are spared, the instrument tends to follow tissue planes and to dissect fat and other soft tissues selectively. We performed a prospective, randomized, controlled trial in 73 patients comparing the safety and efficacy of a prototype ultrasonic dissector with that of electrosurgery and laser during laparoscopic cholecystectomy. Randomization was as follows: ultrasonic dissector, 37 patients; electrosurgery, 21 patients; and laser, 15 patients. The results were not different with respect to patient characteristics, amount of blood loss, technical difficulties, length of hospital stay, or return to work. Subjectively, the ultrasonic dissector was thought to be of special value in isolating the hilar structures, particularly when they were edematous or embedded in fat. The ultrasonic dissector disintegrated the fat, which was rapidly cleared up the suction channel, allowing the cystic duct and artery to be bared with less risk of injury. We concluded that the ultrasonic dissector has unique attributes that contribute to the ease and safety of laparoscopic cholecystectomy.

Repair and regeneration: experimental aspects of spinal cord disease

Regeneration of spinal cord neurons after injury depends on first, the presence of trophic factor(s) which prevent death, induce growth and maintain the viability of the neurone and second, the regenerating neurites must overcome glial scars, extracellular matrices and white matter barriers to reinnervate their target. Attempts at promoting regeneration by using grafts of prosthetic material, Schwann cells and neural tissue have largely been unsuccessful. Although growth could be induced, penetration of regenerating neurites through damaged areas of the spinal cord has been limited. There is as yet very little beneficial functional recovery.

The effects of adrenaline and atropine on oxytocin-induced estrus in the goat

Oxytocin-induced luteolysis in goats was associated with significant increases in peripheral plasma concentrations of 13,14-dihydro-15-keto-prostaglandin (PG) F(2alpha) (PGFM). This effect was not inhibited by concomitant administration of adrenaline (1 mg), although increases of PGFM were both delayed and diminished. Administration of atropine, a muscarinic cholinergic antagonist, inhibited the effect of oxytocin in three out of five goats. In these animals, increases in PGFM were inhibited.

Effect of oxytocin on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin F2 alpha during the oestrous cycle and early pregnancy in the goat

The effect of subcutaneous oxytocin on plasma concentrations of 13,14-dihydro-15-keto-prostaglandin (PG) F2 alpha (PGFM) was examined in the goat at various periods during the oestrous cycle and early pregnancy. 100 i.u. oxytocin was administered daily for 4 day, the dose being divided and given at 0900 and 2100 h; PGFM concentrations were assessed after the first treatment of each day. On days 3-6 (oestrus, day 0) PGFM concentrations increased significantly (P less than 0.001) within 15 minutes and both non-pregnant and mated goats exhibited oestrus behaviour by day 7. Significant (P less than 0.01) increases in PGFM were also produced on days 7-10, in both non-pregnant and pregnant goats, but the responses diminished from day 7 to day 10; only one goat (non-pregnant) came into oestrus. There was a marked difference in response between groups, however, during days 12-15. In non-pregnant goats significant (P less than 0.05) increases in PGFM were detected on days 13-15, but in pregnant animals oxytocin was without effect. Similarly, oxytocin did not increase PGFM concentrations on days 17-20 of pregnancy. However, uterine responsiveness reappeared in pregnant goats with significant (P less than 0.01) increases in PGFM on days 24 and 25.

Multiplication and Virulence in Plant Tissues of Escherichia coli Clones Producing Pectate Lyase Isozymes PLb and PLe at High Levels and of an Erwinia chrysanthemi Mutant Deficient in PLe

The phytopathogenic enterobacterium Erwinia chrysanthemi strain EC16 produces four isozymes of pectate lyase (PL), an extracellular enzyme that macerates parenchymatous plant tissues and kills plant cells. A 1.8-kilobase Eco RI DNA fragment containing the entire pelE gene was deleted from the E. chrysanthemi chromosome by marker exchange of a cloned fragment that had been modified in vitro. The resulting mutant, UM1001, produced the isozymes PLa, PLb, and PLc, but not PLe. Mutant UM1001 was compared with wild-type E. chrysanthemi , with Escherichia coli JA221, and with JA221 containing expression vectors with cloned pel genes producing high levels of PLe (pPEL748) or PLb (pPEL343) for the ability to multiply and cause symptoms in intact potato tubers. Tubers were injected with less than 100 bacteria per inoculation site and incubated aerobically or anaerobically. While maceration occurred only in anaerobically incubated tubers, all of the bacteria, including nonpectolytic E. coli controls, multiplied substantially under all conditions. E. coli JA221(pPEL748) caused significantly more maceration than E. coli JA221(pPEL343) or wild-type E. chrysanthemi. Mutant UM1001 caused significantly less maceration than the wild-type E. chrysanthemi. The results establish the importance of PLe in the pectolytic arsenal of E. chrysanthemi by demonstrating that production of PLe can enable E. coli to aggressively macerate tuber tissue and that deletion of pelE significantly diminishes the virulence of E. chrysanthemi.

Responses of Rj(1) and rj(1) Soybean Isolines to Inoculation with Bradyrhizobium japonicum

We evaluated the symbiotic phenotypes of nodulation-restrictive and normal soybean isolines by inoculating Clark (genotypically Rj(1)Rj(1)) and mutant Clark-rj(1) (genotypically rj(1)rj(1)) seedlings in plastic growth pouches. Nodules first appeared on Clark seedlings inoculated with Bradyrhizobium japonicum USDA 94 after 6 days. The mean number of nodules per plant was 13.9 +/- 0.8 after 24 days. In contrast, Clark-rj(1) seedlings first nodulated at 12 days, and the mean number of nodules per plant was only 1.7 +/- 0.3 at 24 days. Segments from infectible zones of primary roots, i.e. near the position occupied by the root tip at the time of inoculation, were sectioned serially. Clark roots contained cortical cell divisions and a few infection threads in question mark-shaped root hairs by 2 days after inoculation. Typical nodules developed soon thereafter. Analogous serially sectioned segments from Clark-rj(1) roots lacked these responses. This prompted us to section nodules and adjacent tissues from other parts of Clark and Clark-rj(1) roots. Clark roots contained cortical cell divisions, many associated with infected root hairs. Cortical cell divisions occasionally were present in Clark-rj(1), and a few infection threads were visible in surface cells. The presence of infection threads within Clark-rj(1) nodules was confirmed by transmission electron microscopy. Thus, although B. japonicum USDA 94 fails to elicit the wild-type spectrum of responses in the infectible zones of primary roots, it can infect Clark-rj(1) via infection threads.

Rickets in premature infants fed different formulas

To study the role of formula as a cause of rickets, we randomly assigned 46 very-low-birth-weight (VLBW) infants (less than or equal to 1,500 gm) to one of three groups receiving either Isomil, a soy isolate formula, Similac with Iron, a common milk-based formula, or Similac 24 LBW, a hypercaloric milk-based formula designed for low-birth-weight infants during the first three to four months of life. Postnatal changes in serum calcium, phosphorus, alkaline phosphatase, and albumin were monitored during this study. Radiologic diagnosis of rickets was made in 60% of infants fed Isomil and 5% fed Similac with Iron. Significantly low levels of serum phosphorus and high levels of serum alkaline phosphatase were also seen in infants fed Isomil. The exact cause of the biochemical changes and the high incidence of rickets among infants fed Isomil is not clear. Poor solubility and possibly the decreased bioavailability of minerals in soy isolate formula may be important. We conclude that rickets occurs with high frequency among VLBW infants fed soy isolate, but not milk-based formulas. We suggest that prolonged feeding of soy isolate formulas should be avoided in VLBW infants.

The preoperative detection of axillary lymph node metastases in breast cancer by isotope imaging

Axillary lymphoscintigraphy using 99Tcm-labelled liposomes was carried out in 40 patients with breast cancer as a part of pretreatment staging in an attempt to improve the accuracy of axillary evaluation. Patients were injected interstitially in the periareolar region of each breast with 250–300 μCi of 99Tcm-labelled liposomes. Subsequently the patients were imaged with a gamma-camera using computerized data processing. Interpretation of images was based on prior experimental data; a diminished uptake of isotope by the primary regional lymph node (PRLN) and the group of axillary regional lymph nodes (RLN) draining the tumour, when compared to the control side, was considered to be abnormal and to suggest node metastases. An equal or enhanced uptake by the PRLN or RLN draining the tumour, when compared to the control side, was considered normal, indicating an absence of lymph node metastases. Eighteen patients (45 per cent) had abnormal scans and 14 patients (35 per cent) had normal scans. Eight patients (20 per cent) had technically unsatisfactory images where axillary nodes could not be identified. Twenty-two patients of the 32 with evaluable scans had correlation of preoperative images with postsurgical axillary lymph node histopathology. One patient out of 12 with an abnormal scan had normal lymph nodes on serial sectioning, and 2 patients out of 10 with normal scans had lymph node metastases. Eight of the 32 patients (25 per cent) with evaluable images had enhanced uptake of isotope by the PRLN and RLN draining the tumour. In 3 of these cases a marked reactive hyperplasia only was shown on histopathological examination, in 2 cases the reactive hyperplasia was associated with lymph node metastases, accounting for the 2 false negative interpretations. This preliminary study suggests that axillary lymphoscintigraphy may be of value in preoperative staging in breast cancer. Long term studies are needed to evaluate the prognostic potential of such a test as a measure of macrophage function. Further studies, by blind replication, are required to evaluate the accuracy of axillary lymph node imaging.

Traumatic diaphragmatic hernia

The records of 36 patients with traumatic diaphragmatic hernia (TDH) were reviewed. In 14, acute hernias were diagnosed, but the diagnosis was made one month to 15 years after injury in 22 patients with chronic hernia. Seven acute TDHs were due to blunt and seven to penetrating trauma. Four chronic TDHs were due to blunt and 18 to penetrating trauma. Chest pain, abdominal pain, or dyspnea occurred in each acute case and in 18 of 22 chronic cases. Plain chest roentgenograms were abnormal in 33 of 36 cases. Pleural effusion or abnormal diaphragmatic contour were common abnormal findings. Supradiaphragmatic bowel, pathognomonic of TDH, was evident in seven acute and eight chronic hernias. Celiotomy was routinely employed in acute hernias, celiotomy or thoracotomy in chronic hernias. There were three deaths, two with associated CNS injury and one with chronic pulmonary disease.