Evaluation of a novel synthetic sealant for inhibition of cardiac adhesions and clinical experience in cardiac surgery procedures

BACKGROUND

Pericardial adhesions subject patients requiring reoperation to potential injuries to the heart, great vessels, and cardiac grafts during the re-sternotomy. These adhesions can severely complicate re-operations by making re-entry hazardous, impeding orientation and visibility, increasing the amount of blood loss, and prolonging the operation time. The efficacy of an in situ-forming polyethylene glycol (PEG) material, CoSeal surgical sealant (CoSeal), for inhibiting cardiac adhesions in an animal model is reported. It is currently estimated that 10-20% of patients undergoing aortic valve replacement and coronary artery bypass grafting (CABG) will require a second operation later in their lives. Successful clinical experience using CoSeal for sealing suture lines of the aorta and CABGs with the data reported here suggest that CoSeal may have multiple applications in cardiac surgery.

METHODS

In rabbits, a sternotomy and pericardiotomy were performed to expose the heart and the epicardium of the left ventricular surface. The epicardium was abraded for five minutes with dry gauze and cotton to develop punctate bleeding. In treated animals, CoSeal(R) or Tissucol(R) was applied directly to the abraded bleeding epicardium while retracting the pericardium. The pericardium was released, and the material over-sprayed to the cut edges of the pericardium. No material was applied in control animals.

RESULTS

At necropsy, CoSeal(R) was found to significantly reduce the formation of adhesions, the tenacity of the adhesions, and the percent of the abraded site with adhesions as compared to surgical control and Tissucol. Tissucol showed no significant difference from the surgical control in any adhesion parameter. CoSeal treated hearts showed re-establishment of the mesothelial layer and tissue morphology similar to a normal un-operated heart. During the clinical cardiac procedures, CoSeal was easily mixed and applied to the suture lines of the aorta and coronary artery grafts. No bleeding was found at the suture lines.

CONCLUSIONS

In the rabbit cardiac adhesion model, CoSeal significantly reduced the formation of adhesions as compared to surgical control and Tissucol, and demonstrated good biocompatibility. In CoSeal treated patients undergoing cardiopulmonary bypass or vessel repair, sealing was achieved comparable to previous cases using Tissucol fibrin sealant. CoSeal effectively sealed the suture lines of the aorta and coronary artery bypass grafts.

Facilitated coronary anastomosis using a nitinol U-Clip device: bovine model

OBJECTIVE

The coronary anastomosis is the most difficult part of the coronary bypass procedure, particularly when using a minimally invasive technique. Methods to facilitate coronary anastomosis will make the minimally invasive approach to coronary bypass feasible. We sought preclinical validation and testing of the design and efficacy of a self-closing penetrating clip that can be used to facilitate the creation of graft-to-coronary end-to-side anastomosis.

METHODS

The nitinol U-Clip device (Coalescent Surgical, Inc, Sunnyvale, Calif) was used in 13 consecutive calves (63-118 kg). In each animal, the device was (1) used to create an anastomosis of the right internal thoracic artery to a coronary artery with the heart beating and (2) compared to polypropylene suture when used to repair two carotid arteriotomies. Intraoperative, 1-week, 8-week, and 26-week postoperative angiograms and detailed histopathologic examinations were used to evaluate anastomotic patency and healing characteristics.

RESULTS

The nitinol U-Clip device successfully created right internal thoracic artery-coronary artery anastomoses and repaired carotid arteriotomy sites in 13 consecutive calves. The clip was precisely placed by means of the integrated suture and needle in a fashion similar to that used for conventional suture. The clip met design specifications by reliable release and automatic closure, thereby eliminating knot tying and assisted suture management. At the time of harvest, angiography showed widely patent coronary anastomoses (FitzGibbon grade A criteria, n = 13) and carotid arteriotomy repair sites (n = 13). Histopathologic evaluation confirmed normal healing with smooth circumferential neointimal resurfacing at the anastomotic and repair sites.

CONCLUSIONS

The nitinol U-Clip design and function was validated in the formation of bovine coronary anastomoses on the beating bovine heart with excellent graft patency and healing characteristics. The nitinol U-Clip device tests favorably when compared with conventional sutures in carotid artery repair.

Current orientation induced by magnetic stimulation influences a cognitive task

The direction of the current induced by transcranial magnetic stimulation (TMS) over the motor cortex has been observed to influence the threshold and latency of evoked muscle responses. This study investigates the effect of TMS-induced current orientation (ICO) over the prefrontal cortex, on a specific cognitive task (memory-guided saccade). TMS was applied with a figure-of-eight coil, placed at one of eight different orientations over the prefrontal cortex. The most effective ICO was antero-lateral, which is a different optimal ICO from that seen over the hand area of the motor cortex. This demonstrates that ICO can alter the effect of TMS on cognitive functions and that ICO is an independent variable that should not be ignored when designing TMS studies.

Changes in the motility, morphology, and F-actin architecture of human dendritic cells in an in vitro model of dendritic cell development

An in vitro model has been developed for analyzing the two developmental phases of human dendritic cell (DC) migration. Employing the age of the culture and the addition of GM-CSF, IL-4, and serum to regulate cellular phenotype, and glass coated with acid-precipitated human plasma proteins to facilitate persistent DC translocation, the model produces three sequential in vitro phenotypes with the following suggested in vivo counterparts: (1) DCs recently isolated from blood, which are highly polar and motile, and reflect the behavior of "undifferentiated" DCs that must extravasate from the blood stream and migrate into peripheral tissue; (2) large, nonmotile, stellate DCs, which reflect the highly "differentiated" signature phenotype of DCs in peripheral tissue, whose function is to capture foreign antigens; and (3) the large, motile "dedifferentiated" DCs, which reflect the behavior of "veiled cells" that have captured an antigen, retracted dendritic processes, migrated out of peripheral tissue, and are in the process of transporting a captured antigen to a proximal draining lymph node for presentation to T cells. Computer-assisted motion analysis of the three sequential phenotypes and fluorescent staining of F-actin reveal three unique behavioral states and unique cellular architecture consistent with inferred in vivo function. This in vitro model should serve as a starting point for elucidating the cues and molecular mechanisms involved in the regulation of DC differentiation and motility.

Acholeplasma vituli sp. nov., from bovine serum and cell cultures

Organisms isolated from commercial foetal bovine serum and from cell culture lines containing such serum supplements were found to consist of non-helical, non-motile, pleomorphic coccoid forms. One strain (FC 097-2T) cultivated directly from foetal bovine serum was selected for characterization. In ultrastructural examination, individual round cells lacked cell wall structures and cells varied in size, with a mean diameter of about 700 nm. However, variable numbers of cells were filterable through membranes of 300 nm. Optimum growth occurred between 30 and 37 degrees C. The organism fermented glucose, fructose and mannose, but did not hydrolyse arginine. The strain was insensitive to 500 U penicillin ml(-1) and was capable of growing in the absence of serum or cholesterol. The organism was serologically distinct from all 13 currently described species in the genus Acholeplasma and from other sterol-requiring species in the genus Mycoplasma, using growth inhibition, immunoperoxidase and immunofluorescence tests. Strain FC 097-2T was found to have a DNA G+C composition between 37.6 +/- 1 mol% and 38.3 +/- 1 mol%. The genome size was determined to be 2095 kbp. The 16S rDNA sequence of strain FC 097-2T was compared to 16S rDNA sequences of other mollicutes in nucleotide databases. No deposited sequence was found to be identical; the closest relatives were several members of the genus Acholeplasma. On the basis of these findings and other similarities to acholeplasmas in morphology and growth, the absence of a sterol requirement for growth, and similar genomic characteristics, the organism was assigned to the genus Acholeplasma. Strain FC 097-2T is designated the type strain (ATCC 700667T) of a new species, Acholeplasma vituli.

Effect of surrogate tolerogenesis on the vascular rejection of pig heart xenografts

BACKGROUND

Organ xenografts are fulminantly rejected by antibody-mediated vascular rejection. Surrogate tolerogenesis (ST), the induction of tolerance within the donor, is effective with aorta xenografts. This preliminary study assesses the effect of ST on preformed antibodies and rejection of porcine heart xenografts.

METHODS

Tolerance to the donor pig was induced by infusing recipient marrow into fetal pigs. Later, pig splenocytes were transfused and heterotopic pig hearts transplanted using chimeric or nonchimeric pigs. Anti-pig antibodies were assessed.

RESULTS

With ST alone, xenografts developed cellular rejection at 4-6 days, whereas control grafts developed vascular rejection at 3-4 days (cellular vs. vascular, P<0.03). There was a reduction in preformed antibodies (P<0.03). ST combined with moderate cyclosporine prevented rejection at 9+ and 25 days in sensitized recipients compared with vascular rejection at 0.5-2 days for controls (P<0.07).

CONCLUSIONS

ST seems to provide protection against vascular rejection. The cellular rejection seems sensitive to cyclosporine.

Prolonged discordant cardiac xenograft survival in newborn recipients

BACKGROUND

We previously demonstrated very low levels of xenoreactive natural antibodies in newborns, suggesting the possibility of prolongation of xenograft survival in newborn recipients. We used a pig-to-newborn goat heterotopic cardiac xenograft model to examine our hypothesis that hyperacute rejection would be absent in newborn recipients and that both humoral and cellular rejection would participate in the late phase of discordant xenograft rejection.

METHODS AND RESULTS

The serum of newborn goats was found to have very low titers of natural anti-pig antibodies. Newborn pig hearts were transplanted heterotopically into the neck of four unmanipulated newborn goats: none of these xenografts underwent hyperacute rejection. Dilation of the xenografts and decreased contractility were observed 4 to 6 days after transplantation, and the xenografts eventually ceased functioning between 6 and 8 days after transplantation. Blood samples collected after transplantation demonstrated a dramatic increase in anti-pig xenoantibody titers and correlated with histological studies demonstrating features consistent with delayed humoral rejection, including reactive vascular endothelial and perivascular stromal cells, marked capillary congestion, and interstitial hemorrhages. Scant to diffuse perivascular and interstitial infiltration of activated lymphoid cells occurred.

CONCLUSIONS

Our study demonstrates that hyperacute rejection does not occur, allowing limited prolongation of xenograft survival in a pig-to-newborn goat cardiac xenograft model. We propose that this is attributable, at least in part, to the very low titers of natural antibodies in newborn recipients. Delayed xenograft rejection, however, remains an important problem in these newborn recipients. This delayed xenograft rejection is likely the result of both humoral and cellular rejection mechanisms.

Echocardiographic recognition of iatrogenic aortic valve leaflet perforation

BACKGROUND

There is a paucity of literature regarding iatrogenic aortic valve perforation after cardiac operations performed in the vicinity of the aortic valve. This report describes the echocardiographic recognition of iatrogenic aortic valve perforation.

METHODS

Among 6 patients who had previously under-gone non-aortic valve cardiac operations, a diagnosis of iatrogenic aortic regurgitation was made by transthoracic two-dimensional echocardiography and Doppler color flow imaging.

RESULTS

The location of the aortic valve leaflet perforation varied and depended on the site of the previous intracardiac lesion repair. Repeat operations in 5 patients confirmed the echocardiographic findings. Aortic valve repair was confirmed in 2 patients by transesophageal echocardiography, whereas aortic valve replacement became necessary in 2 other patients. A fifth patient with acquired cardiomyopathy underwent orthotopic heart transplantation.

CONCLUSIONS

A detailed two-dimensional echocardiographic examination, along with color flow imaging, should be done to evaluate iatrogenic aortic valve perforation in patients with a new murmur of aortic regurgitation after cardiac operations in proximity to the aortic valve. Precise preoperative diagnosis of this lesion allows optimal surgical planning and treatment.

Nonpenetrating clips for coronary anastomosis

BACKGROUND

A nonsuture clip technique (nonpenetrating titanium clips applied to everted tissue edges at high compressive forces) was used to perform coronary anastomoses in a clinical setting.

METHODS

Clipped coronary anastomoses were performed in 10 patients. The anastomoses incorporated the left internal mammary artery to the left anterior descending artery (n = 1) and the saphenous vein to the right coronary artery (n = 5), the posterior descending artery (n = 2), the diagonal artery (n = 2), and one vein-to-vein proximal anastomosis (n = 1).

RESULTS

The mean duration for completion of the anastomoses was 15 minutes (range, 7 to 20 minutes). This time was reduced from 20 minutes at the beginning of the clinical experience to 7 minutes for the last 3 patients. No technical complication was related to clip application and all patients had uneventful outcomes. Three anastomoses studied by coronary angiography were patent without stenosis.

CONCLUSION

The clipped anastomotic technique has a rapid learning curve, the same safety as suture methods, and the potential for facilitating endoscopic vascular reconstructions.

Delayed primary repair of intrathoracic esophageal perforation: is it safe?

The management of intrathoracic esophageal perforation with delayed diagnosis is a subject of controversy. Because of the obvious advantages of primary repair as a simple single-stage operation, this technique was preferentially used to treat 18 of 22 consecutive patients with esophageal perforation. These patients were stratified into three groups according to the time interval between perforation and repair: group A, less than 6 hours, five patients (28%); group B, 6 to 24 hours, six patients (33%); and group C, more than 24 hours, seven patients (39%). Group A patients were older (p < 0.05) and group B had fewer iatrogenic perforations (B, 17%; A, 80%; C, 57%, p < 0.1). Additional tissue was used to buttress the repair site in all three groups (A, 3/5 patients, 60%; B, 4/6 patients, 67%; C, 6/7 patients, 86%; p = not significant). In seven patients (39%), a fundic wrap was used to reinforce the site of primary repair. The outcomes of the three groups were analyzed. Group A had the lowest proportion of postoperative leaks (A, 0/4 patients, 0%; B, 4/6 patients, 67%; C, 5/6 patients, 83%; p < 0.05) and postoperative morbidity (A, 2/5 patients, 40%; B, 6/6 patients, 100%; C, 6/7 patients, 86%; p < 0.1). However the increased incidence of leak and morbidity did not lead to an increase in mortality. One death occurred in each group, with an overall mortality of 17% (A, 1/5 patients, 20%; B, 1/6 patients, 17%; C, 1/7 patients, 14%; p = not significant). We conclude that in the era of advanced intensive care capabilities, primary repair of intrathoracic esophageal perforation can be safely accomplished in most patients regardless of the time interval between perforation and operation. Leakage at the suture site is common unless primary repair is carried out without delay. Postoperative leakage, however, is usually inconsequential and does not necessarily result in an adverse outcome.

Uniformity of perfusion in all regions of the human heart by warm continuous retrograde cardioplegia

BACKGROUND

Animal models have suggested that retrograde cardioplegia may be poorly distributed to septal and right ventricular regions of the heart; if true, this may have dangerous implications for warm continuous retrograde cardioplegia in humans. We have previously shown that blood gases from coronary arteries during warm continuous retrograde cardioplegia represent postcapillary "venous" gases and are reflective of myocardial perfusion.

METHODS

To determine regional differences in perfusion during warm continuous retrograde cardioplegia we obtained blood gases from three regions of the heart in 141 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement, or both. Right heart perfusion was determined by blood gases from the right coronary artery orifice, acute marginal, or posterior descending coronary arteries; circumflex or lateral wall perfusion was determined by samples from obtuse marginal or intermediate coronary arteries; and anterior wall/septal perfusion was determined by left anterior descending and diagonal coronary artery blood gases. Warm continuous retrograde cardioplegia flow ranged from 150 to 300 mL/min depending on heart size. A mean of 4 +/- 1 samples/patient were obtained.

RESULTS

There were no regional differences in postcapillary pH, carbon dioxide tension, or CO2 production during warm continuous retrograde cardioplegia. Oxygen tensions were lower in the right and anterior/septal regions of the heart, implying more O2 uptake. No regional acidosis, consistent with poor perfusion, could be detected.

CONCLUSIONS

We conclude that, unlike experimental models, regional myocardial perfusion, including the right heart, is uniform during "high-flow" warm continuous retrograde cardioplegia in humans.

Percutaneous transluminal coronary angioplasty failures in patients with multivessel disease. Is there an increased risk?

In recent years, there has been a nationwide trend toward performing percutaneous transluminal coronary angioplasty in patients with multivessel coronary artery disease. The clinical course of 57 consecutive patients who required emergency first-time coronary artery bypass grafting operations were reviewed to assess for difference in outcome between the 28 patients (49%) with single-vessel disease and the 29 patients (51%) with multivessel disease. The two groups were similar in preoperative characteristics except for a higher proportion of chronic obstructive pulmonary disease in the patients with multivessel disease (p = 0.03). Twice as many patients with multivessel disease were in shock (single-vessel disease = 4 [14%], multivessel disease = 8 [28%], p = not significant) en route to the operating room and significantly more patients with multivessel disease required on-going cardiopulmonary resuscitation (single-vessel disease = 0 [0%], multivessel disease = 5 [17%], p = 0.03). Significantly more coronary artery bypass grafts were placed in the patients with multivessel disease (single-vessel disease = 1.5 +/- 0.6, multivessel disease = 2.9 +/- 0.7, p < 0.01), which required longer aortic clamping time (p = 0.02) and cardiopulmonary bypass time (p < 0.01). There were seven postoperative deaths; all but one occurred in patients with multivessel disease (single-vessel disease = 1 [4%], multivessel disease = 6 [21%], p = 0.05). According to multivariate analysis, incremental risk factors of mortality were preoperative shock (p < 0.01), urgent or emergency percutaneous transluminal coronary angioplasty (p = 0.06), and multivessel disease (p = 0.12). Despite a similar incidence of myocardial infarction (single-vessel disease = 8 [29%], multivessel disease = 12 [41%], p = not significant), patients with multivessel disease had a higher incidence of cardiac morbidity (single-vessel disease = 4 [14%], multivessel disease = 11 [38%], p = 0.04) and noncardiac morbidity (single-vessel disease = 4 [14%], multivessel disease = 12 [41%], p = 0.02). By multivariate analysis, incremental risk factors of morbidity were preoperative shock (p < 0.01), multivessel disease (p = 0.02), and ejection fraction < 50% (p = 0.07). In the subset of patients with multivessel disease, preoperative shock, ejection fraction < 50, and an age of 60 years or greater were associated with higher morbidity and mortality. In conclusion, the risk of percutaneous transluminal coronary angioplasty failure is considerably higher in patients with multivessel disease. In certain subsets of patients with multivessel disease, coronary artery bypass grafting would be a safer procedure when compared with percutaneous transluminal coronary angioplasty for initial myocardial revascularization.

Successful survival of primates receiving transplantation with "dead," nonbeating donor hearts

A paucity of donor organs is the principal limitation in human heart transplantation. Prompted by our short-term studies of reanimating "dead" donor hearts in sheep, we applied the same reperfusion modifications in juvenile baboons to determine human applications in an anoxic arrest model (as occurs when non-brain-dead patients are extubated and allowed to die). Ten juvenile baboons (mean weight 3.6 kg) were studied. Five baboons were used as donors. After being anesthetized, donors were pretreated with methylprednisolone (Solu-Medrol), 50% dextrose, nifedipine, and prostaglandin E1 and then paralyzed and extubated. Donors became pulseless at 7 +/- 1 minutes and had electric arrest 9 to 18 minutes after paralysis. The five donors were left undisturbed and warm for 15, 22, 30, 30, and 31 minutes, respectively, after asystole. They were then given 250 ml of 4 degrees C Roe's crystalloid cardioplegic solution via the aortic root and the hearts were explanted into iced Euro-Collins solution. Five baboons served as recipients. After donor harvest, recipients were placed on cardiopulmonary bypass, given prostaglandin E1, and cooled to 18 degrees C; circulatory arrest was instituted and the recipient's heart excised. The donor heart was transplanted in an orthotopic position. Before reinstitution of bypass, 250 ml of terminal leukocyte-depleted blood cardioplegic solution was given, then bypass was restarted and the hearts were reperfused for 60 minutes. All animals were weaned from bypass without the use of inotropic agents. All animals were extubated within 2 to 4 hours after bypass and received standard immunosuppression. Peak creatine kinase MB/total creatine kinase ratio was 0.2% +/- 0.2%. Postoperative ejection fractions by echocardiography were 75% to 80% (mean 76%). Animals survived 1, 9, 13, 16, and 34 days, with three deaths caused by acute rejection and one each by stroke and diarrhea/dehydration. Pathologic findings showed no areas of fibrosis or ischemic damage. We conclude that successful reanimation and engraftment can be achieved with the use of the asystolic primate heart; this work suggests that human application is realistic and could greatly expand the donor pool.

Fetal lamb pulmonary hypoplasia: pulmonary vascular and myocardial abnormalities

Neonatal pulmonary hypoplasia resulting from a congenital diaphragmatic hernia (CDH) produces hemodynamic changes and morphologic abnormalities of the pulmonary vasculature. To characterize the myocardial and pulmonary vascular status of the fetus with pulmonary hypoplasia, we studied four chronically instrumented, near-term fetal lambs with pulmonary hypoplasia, induced by producing a diaphragmatic hernia. We found an elevation in the pulmonary arterial pressure (control, 43.8 +/- 5.9 mmHg; CDH, 58.8 +/- 9.1 mmHg; p < 0.05), an elevation in the systemic arterial pressure (control, 43.8 +/- 0.48 mmHg; CDH, 58.6 +/- 6.7 mmHg; p < 0.05), and an elevation in the pulmonary vascular resistance (control, 0.47 +/- 0.11; CDH, 3.87 +/- 1.9; p < 0.05). In addition, though the total pulmonary blood flow was reduced (control, 83.5 +/- 32.9 mL/min; CDH, 22.2 +/- 17.6 mL/min; p < 0.05), the blood flow reduction was proportional to the reduction in the lung mass (control, 79.8 +/- 28.1 [in flow per 100-g lung weight]; CDH, 85.4 +/- 71.7). The increase in the pulmonary vascular resistance in relation to the unit lung mass (control, 0.55 +/- 0.33; CDH, 0.99 +/- 0.5) was not as pronounced as its increase in relation to the total pulmonary blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

The Hayek oscillator: a new method of ventilation in microlaryngeal surgery

The Hayek oscillator is an externally (body) mounted cuirass ventilator used in the intensive care unit. We have used it to ventilate patients undergoing microlaryngeal surgery. It was found to be a relatively safe method of ventilation in these cases, with the advantage of dispensing with any form of endolaryngeal or endotracheal intubation.

Mycoplasma indiense sp. nov., isolated from the throats of nonhuman primates

Mycoplasmas isolated from the throats of a rhesus monkey and a baboon within 3 days of their arrival from India were shown to be serologically distinct from 104 previously recognized Mycoplasma and Acholeplasma spp. Two mycoplasma colonies were cloned and examined in detail for morphology, growth, and biochemical characteristics. The two strains were closely related and had the following properties: guanine-plus-cytosine content of 32 mol%, requirement for sterol, arginine hydrolysis, and anaerobic growth. Glucose was not metabolized, and urea was not hydrolyzed. Strain 3T (= NCTC 11728) is the type strain of a new species, Mycoplasma indiense.

Acholeplasma cavigenitalium sp. nov., isolated from the vagina of guinea pigs

A mollicutes isolated from a guinea pig vagina was shown to be serologically distinct from previously recognized Mycoplasma and Acholeplasma species. Colonies isolated from 10 different guinea pigs were cloned and examined in detail. These strains were closely related and had the following properties: guanine-plus-cytosine content of 36 mol%, no requirement for sterol, and aerobic growth. Glucose was not metabolized, and arginine and urea were not hydrolyzed. Strain GP3 (= NCTC 11727) is the type strain of a new species, Acholeplasma cavigenitalium.

Mycoplasma simbae sp. nov., Mycoplasma leopharyngis sp. nov., and Mycoplasma leocaptivus sp. nov., isolated from lions

Mycoplasmas isolated from the throats of lions were shown to belong to three serotypes, all of which were serologically distinct from the previously recognized Mycoplasma and Acholeplasma spp. Eight mycoplasma colonies were cloned, including one from a leopard (strain LP), and were examined in detail for morphology, growth, and biochemical characteristics. The strains had the following properties: guanine-plus-cytosine contents of 37 mol% (strain LXT [T = type strain]), 28 mol% (strain LL2T), and 27 mol% (strain 3L2T) and a requirement for sterol. Strain 3L2T metabolized glucose, which was not metabolized by strains LXT and LL2T. Arginine and urea were not hydrolyzed. Strain LX (= NCTC 11724) is the type strain of a new species, Mycoplasma simbae; strain LL2 (= NCTC 11725) is the type strain of a second new species, Mycoplasma leopharyngis; and strain 3L2 (= NCTC 11726) is the type strain of a third new species, Mycoplasma leocaptivus.

Acholeplasma multilocale sp. nov., isolated from a horse and a rabbit

Acholeplasma strains were isolated from the nasopharynx of a horse (strain PN525T [T = type strain]) and the feces of a rabbit (strain B1). One clone of strain PN525T and one clone of strain B1 were examined in detail. These clones were indistinguishable from each other and were serologically distinct from the previously described Acholeplasma and Mycoplasma spp. The strains had the following properties: guanine-plus-cytosine content of 31 mol%; sterol was not required for growth, which occurred under both aerobic and anaerobic conditions; glucose was metabolized; and arginine was hydrolyzed. Strain PN525 (= NCTC 11723) is the type strain of a new species, Acholeplasma multilocale.

Mycoplasma pulmonis infection with regard to embryo freezing and hysterectomy derivation

Eggs taken from the oviducts of mice, inoculated 3 weeks previously with Mycoplasma pulmonis in the peritoneal cavity, were shown to be contaminated, and mycoplasmas were not eradicated by washing the eggs three times. Zona-free eggs were also infected. Embryos cultured for 24 hours in medium M16 were clear of infection. Sperm from infected males was not significantly worse in the fertilization of uninfected eggs.

Mycoplasma spermatophilum, a new species isolated from human spermatozoa and cervix

A mycoplasma isolated from human spermatozoa and a human cervix was shown to be serologically distinct from 98 previously recognized Mycoplasma and Acholeplasma spp. Six mycoplasma colonies were cloned and examined in detail for morphology, growth, and biochemical characteristics; five of these were from sperm samples and one was from a cervix. These strains were closely related and had the following properties: guanine-plus-cytosine content of 32 mol%, requirement for sterol, and anaerobic growth. Glucose was not metabolized, and arginine and urea were not hydrolyzed. Strain AH159 (= NCTC 11720) is the type strain of a new species, Mycoplasma spermatophilum.

Mycoplasma oxoniensis, a new species isolated from Chinese hamster conjunctivas

Mycoplasmas which were distinct from Mycoplasma cricetuli were isolated from the conjunctivas of Chinese hamsters. Two clones, which were derived from a single colony and were obtained on separate occasions, were examined in detail for morphology, growth, and biochemical characteristics. These clones were indistinguishable from each other and had the following properties: guanine-plus-cytosine content of 29 mol%, requirement for sterol, facultatively anaerobic, and positive for glucose metabolism. They were serologically distinct from M. cricetuli and all 94 other previously described Mycoplasma and Acholeplasma spp. One of them, strain 128 (= NCTC 11712), is designated the type strain of a new species, Mycoplasma oxoniensis.

Mycoplasmas, a review of surveys examining human genital infections and experimental infection in mice with special reference to in vitro fertilization

Patients attending an "In Vitro Fertilization" clinic were shown to be commonly infected in the semen with Ureaplasma urealyticum (29%) and Mycoplasma hominis (12%). Other mycoplasmas were rarely recovered. M. hominis was not eradicated from sperm by washing, although washing removed 71% of the ureaplasmas from infected semen. There was a significantly higher incidence of U. urealyticum and M. hominis in patients with cervical intraepithelial neoplasia (P = less than 0.05 and P = less than 0.01 respectively) than in controls. The results showed a possible association of U. urealyticum and M. hominis with CIN type 3. Mouse experiments showed that M. pulmonis has an affinity for genital tissue, adhered to the surface of eggs and could penetrate the zona pellucida, but did not affect fertilization except where pus was present in the oviduct.

Usefulness and limitations of regional cardiac sympathectomy by phenol

We evaluated the completeness and extent of regional sympathetic denervation of the left ventricle after epicardial painting with phenol in anesthetized dogs. In a region encircled by phenol, the effect of electrical stimulation of efferent sympathetic fibers on myocardial contractility and coronary vascular resistance was completely abolished within 30 min. Denervation extended to untreated regions innervated by sympathetic fibers crossing the phenol line. For at least 4 h after phenol application, intravenous infusion of isoproterenol or coronary arterial infusion of tyramine increased myocardial contractility in the denervated region; norepinephrine content and neurotransmitter uptake were normal, indicating that nerve terminals, postjunctional receptors, and myocardium remained functional. However, after 3-14 days, tissue catecholamine content and transmitter uptake in the encircled area were markedly reduced. The results suggest that careful evaluation is necessary in selecting a fully innervated control region in studies employing regional sympathetic denervation with phenol.

Hepatic glycogen synthesis from duodenal glucose and alanine. An in situ 13C NMR study

An in situ and in vivo surface coil 13C NMR study was performed to study hepatic glycogen synthesis from [3-13C]alanine and [1-13C]glucose administered by intraduodenal infusion in 18-h fasted male Sprague-Dawley rats. Combined, equimolar amounts of alanine and glucose were given. Hepatic appearance and disappearance of substrate and concurrent glycogen synthesis was followed over 150 min, with 5-min time resolution. Active glycogen synthesis from glucose via the direct (glucose----glycogen) and indirect (glucose----lactate----glycogen) pathways and from alanine via gluconeogenesis was observed. The indirect pathway of glycogen synthesis from [1-13C]glucose accounted for 30% (+/- 6 S.E.) of total glycogen formed from labeled glucose. This estimate does not take into account dilution of label in the hepatic oxaloacetate pool and is, therefore, somewhat uncertain. Hepatic levels of [3-13C]alanine achieved were significantly lower than levels of [1-13C]glucose in the liver, and the period of active glycogen synthesis from [3-13C]alanine was longer than from glucose. However, the overall pseudo-first-order rate constant during the period of active glycogen synthesis from [3-13C]alanine (0.075 min-1 +/- 0.026 S.E.) was almost 3 times that from [1-13C]glucose via the direct pathway (0.025 min-1 +/- 0.005 S.E.). The most likely reason for the small rate constant governing direct glycogen formation from duodenally administered glucose compared to that from duodenally administered alanine is a low level of glucose phosphorylating capacity in the liver.

The effect of verapamil on cerebral cortical and spinal cord blood flow during proximal descending thoracic aortic occlusion

The mechanism of central nervous system (CNS) protection during proximal descending thoracic aortic cross-clamping (PDTAC) for aortic surgery using calcium channel blocking agents is not known. In order to determine the effect of verapamil on CNS blood flow during PDTAC, we calculated cerebral cortical (CC), proximal spinal cord (PSC), and distal spinal cord (DSC) blood flow using the microsphere method in Grade I beagles. Flow calculations were obtained at baseline (pre-PDTAC), following mobilization of the proximal descending aorta for 5-8 cm by ligating 3-5 pairs of intercostal arteries (ICA), during PDTAC (45 min), and during maximal reperfusion. Two groups were studied: 1) control (Cont) untreated (n = 5); 2) verapamil (Ver) treated (0.4 mg/kg IV just before PDTAC and just before reperfusion) (n = 5).

CONCLUSIONS

I) Proximal ICA ligation produces no compromise to SC blood flow. II) Verapamil may protect the CNS by: 1) maintaining cerebral autoregulation during reperfusion; and 2) dampening hyperperfusion of the distal SC during reperfusion.

Mycoplasmas and in vitro fertilization

Semen samples taken from 135 patients attending an in vitro fertilization clinic were shown to be colonized, 53 with Ureaplasma urealyticum (39%) and 16 with Mycoplasma hominis (12%). An unidentified mycoplasma species was isolated from the sperm of two patients. M. hominis was recovered from all the washed sperm samples taken from colonized semen, whereas washing the sperm eradicated U. urealyticum from 71% of colonized semen. The presence of mycoplasmas in semen made no significant difference to the sperm count, sperm motility, sperm abnormalities, or fertilization of eggs.

Mycoplasma felifaucium, a new species isolated from the respiratory tract of pumas

Mycoplasmas isolated from the throats of three pumas (Felis concolor) were each cloned and examined in detail. All three were serologically and biologically indistinguishable from each other, and were serologically distinct from 83 recognized Mycoplasma and Acholeplasma species. They were designated as a new species, Mycoplasma felifaucium, with strain PU (NCTC 11703) as the type strain.

Auxiliary transplantation of the fetal liver. I. Development of a sheep model

Current methods of orthotopic liver transplantation are expensive, entail high morbidity and mortality, and are limited by a serious shortage of donor organs for the pediatric recipient. Auxiliary transplantation of livers from anencephalics is a potential solution to the problems of size discrepancy and organ availability for the pediatric patient. To investigate the feasibility of auxiliary fetal liver transplantation, we have developed a sheep model of auxiliary transplantation of the fetal liver into the adult neck. We report here the results of the transplantation of 32 fetal lamb livers ranging in age from 100 to 140 days gestation (term 145 days). We conclude that (1) fetal organ harvest can be effectively accomplished by surface cooling followed by umbilical cold perfusion; (2) auxiliary transplantation of the fetal lamb liver is technically feasible; (3) the fetal liver can survive on umbilical inflow alone but function is improved by hepatic arterial inflow; and (4) the fetal liver is sensitive to excessive flow or pressure and is best transplanted in a parallel vascular arrangement. Auxiliary transplantation of the fetal liver is a promising alternative to current methods of liver transplantation.

The growth-inhibitory effects of some dyes on different Mycoplasma and Acholeplasma spp

A microtitre-plate method for evaluating the inhibitory effect of dyes on the growth of mycoplasmas in fluid medium is described. Different species were shown to differ in their sensitivity to dyes. Statistical analysis (a) compared the general sensitivity and resistance of different mycoplasma species to the dyes and (b) showed that the dyes fell into two main groups in their effects on the mycoplasma species.

Mycoplasma cavipharyngis, a new species isolated from the nasopharynx of guinea-pigs

Two mycoplasma strains isolated from the nasopharynx of guinea-pigs in two separate colonies were biochemically and serologically identical, and distinct from 80 Mycoplasma and Acholeplasma spp. One of them, strain 117C (NCTC 11700), is designated the type strain of a new species Mycoplasma cavipharyngis.

Mechanism of action of iontophoresis in the treatment of palmar hyperhidrosis

Sweat glands from the palm of a patient with hyperhidrosis were examined by light and electron microscopy before and after treatment with tap water iontophoresis. No changes in structure were noted after treatment, disclaiming the currently accepted theory that mechanical ductal obstruction is the mechanism of action of this method. Furthermore, we believe the safety and effectiveness of this treatment are supported by our experience.

Rosamicin, a macrolide with in vitro activity against Ureaplasma urealyticum

A new macrolide antibiotic, rosamicin, was shown to have much greater activity in vitro against ureaplasmas isolated from humans than erythromycin or the tetracyclines tested. A marked ureaplasmacidal effect was also shown.

Bacterial and mycoplasma flora of a laboratory colony of the common marmoset (Callithrix jacchus)

A survey was carried out to characterise the bacterial and mycoplasma flora of a closed colony of marmosets, Callithrix jacchus. Bordetella bronchiseptica and Staphylococcus aureus were the only potential bacterial pathogens isolated from the colony; Candida albicans was also identified. S aureus and C albicans were the only organisms which were associated with macroscopic lesions or overt disease. Post mortem examination of the animals proved only reliable method of establishing the presence of some bacterial species in the colony, eg, B bronchiseptica and of obtaining a reliable estimate of the incidence of the various organisms within the colony. The marmosets were all infected with ureaplasmas in the upper respiratory tract. Mycoplasma salivarium was isolated from this site in several animals. There was no evidence to indicate that cross-infection had occurred between the animal technicians and the marmosets, except in one possible case of candidiasis.

Demonstration of mycoplasmas in tissue by the immunoperoxidase technique

The immunoperoxidase technique was shown to be a sensitive method for demonstration of the presence of mycoplasmas in tissue and swabs taken from the upper respiratory tract.

The metabolic inhibition test for mycoplasmas based on phosphatase production

A metabolic inhibition test based upon phosphatase production is described. This is of value for those Mycoplasma species which produce phosphatase but which cannot be examined by the previously published metabolic inhibition techniques.

Hepatitis and brain lesions due to mouse hepatitis virus accompanied by wasting in nude mice

Severe necrotising hepatitis, with microscopic brain lesions containing multi-nucleated giant cells, was observed in specified-pathogen-free nu-nu mice, contained in a semi-protected environment, but within the same room as other, conventional, mice. An entire group of 40 nu-nu mice died within a month, with no evidence of bacterial or parasitic infection. However, cell-free liver filtrates reproduced the liver lesions in specified-pathogen-free Swiss-Schneider mice injected intraperitoneally at up to 21 days of age, but not in baby rats and hamsters.

Electronmicroscopy showed masses of particles resembling mouse hepatitis virus in the liver lesions of the recipient mice, and the identity of the virus was further confirmed serologically and by its physical properties. It was concluded that the infection was caused by a neurotropic variant of mouse hepatitis virus and could have originated from the conventional mice kept in the same room.