Lumbosacral spinal cord epidural stimulation improves voiding function after human spinal cord injury.

Deficits in urologic function after spinal cord injury (SCI) manifest both as a failure to store and empty, greatly impacting daily life. While current management strategies are necessary for urological maintenance, they oftentimes are associated with life-long side effects. Our objective was to investigate the efficacy of spinal cord epidural stimulation (scES) as a promising therapy to improve bladder control after SCI. A bladder mapping study was undertaken for sixteen sessions over the course of four months in an individual with chronic, motor complete SCI. Varying combinations of stimulating cathode electrodes were initially tested during filling cystometry resulting in the identification of an effective configuration for reflexive bladder emptying at the caudal end of the electrode array. Subsequent systematic testing of different frequencies at a fixed stimulus intensity and pulse width yielded lowest post-void residual volumes at 30 Hz. These stimulation parameters were then tested in four additional research participants and found to also improve reflexive voiding efficiency. Taken together with SCI studies on step, stand, voluntary motor control and cardiovascular regulation, these findings further corroborate that scES has an all-encompassing potential to increase the central state of excitability, allowing for the control of multiple body functions, including the urological system.

Post-eruptive flooding of Santorini caldera and implications for tsunami generation.

Caldera-forming eruptions of island volcanoes generate tsunamis by the interaction of different eruptive phenomena with the sea. Such tsunamis are a major hazard, but forward models of their impacts are limited by poor understanding of source mechanisms. The caldera-forming eruption of Santorini in the Late Bronze Age is known to have been tsunamigenic, and caldera collapse has been proposed as a mechanism. Here, we present bathymetric and seismic evidence showing that the caldera was not open to the sea during the main phase of the eruption, but was flooded once the eruption had finished. Inflow of water and associated landsliding cut a deep, 2.0-2.5 km3, submarine channel, thus filling the caldera in less than a couple of days. If, as at most such volcanoes, caldera collapse occurred syn-eruptively, then it cannot have generated tsunamis. Entry of pyroclastic flows into the sea, combined with slumping of submarine pyroclastic accumulations, were the main mechanisms of tsunami production.

Training-Induced Functional Gains following SCI.

We previously demonstrated that daily, hour-long training sessions significantly improved both locomotor (limb kinematics, gait, and hindlimb flexor-extensor bursting patterns) and nonlocomotor (bladder function and at-level mechanical allodynia) functions following a moderate contusive spinal cord injury. The amount of training needed to achieve this recovery is unknown. Furthermore, whether this recovery is induced primarily by neuronal activity below the lesion or other aspects related to general exercise is unclear. Therefore, the current study objectives were to (1) test the efficacy of 30 minutes of step training for recovery following a clinically relevant contusion injury in male Wistar rats and (2) test the efficacy of training without hindlimb engagement. The results indicate that as little as 30 minutes of step training six days per week enhances overground locomotion in male rats with contusive spinal cord injury but does not alter allodynia or bladder function. Thirty minutes of forelimb-only exercise did not alter locomotion, allodynia, or bladder function, and neither training protocol altered the amount of in-cage activity. Taken together, locomotor improvements were facilitated by hindlimb step training for 30 minutes, but longer durations of training are required to affect nonlocomotor systems.

[Extracorporeal membrane oxygenation support for tako-tsubo syndrome after urgent caesarean section]. / Assistance par extracorporeal membrane oxygenation au cours d'un syndrome de tako-tsubo après césarienne en urgence.

Tako-tsubo syndrome is a rare cardiomyopathy secondary to catecholamine toxicity responsible of myocardial stunning. Severe complications such as cardiogenic shock or ventricular arrhythmia can occur. We presented the case of a 32-year-old woman victim of a tako-tsubo syndrome with severe cardiogenic shock during surgical procedure for urgent caesarean section. After refractory haemodynamic failure, the patient benefits from extracorporeal membrane oxygenation support device with success.

Convergence and cross talk in urogenital neural circuitries.

Despite common comorbidity of sexual and urinary dysfunctions, the interrelationships between the neural control of these functions are poorly understood. The medullary reticular formation (MRF) contributes to both mating/arousal functions and micturition, making it a good site to test circuitry interactions. Urethane-anesthetized adult Wistar rats were used to examine the impact of electrically stimulating different nerve targets [dorsal nerve of the penis (DNP) or clitoris (DNC); L6/S1 trunk] on responses of individual extracellularly recorded MRF neurons. The effect of bladder filling on MRF neurons was also examined, as was stimulation of DNP on bladder reflexes via cystometry. In total, 236 MRF neurons responded to neurostimulation: 102 to DNP stimulation (12 males), 64 to DNC stimulation (12 females), and 70 to L6/S1 trunk stimulation (12 males). Amplitude thresholds were significantly different at DNP (15.0 ± 0.6 µA), DNC (10.5 ± 0.7 µA), and L6/S1 trunk (54.2 ± 4.6 µA), whereas similar frequency responses were found (max responses near 30-40 Hz). In five males, filling/voiding cycles were lengthened with DNP stimulation (11.0 ± 0.9 µA), with a maximal effective frequency plateau beginning at 30 Hz. Bladder effects lasted ≈ 2 min after DNP stimulus offset. Many MRF neurons receiving DNP/DNC input responded to bladder filling (35.0% and 68.3%, respectively), either just before (43%) or simultaneously with (57%) the voiding reflex. Taken together, MRF-evoked responses with neurostimulation of multiple nerve targets along with different responses to bladder infusion have implications for the role of MRF in multiple aspects of urogenital functions.

Surgical site infection after central venous catheter-related infection in cardiac surgery. Analysis of a cohort of 7557 patients.

The aim of this study was to establish the relationship between the occurrence of a surgical site infection (SSI) and the presence of a central venous catheter-related infection (CVCRI). The Department of Thoracic and Cardiovascular Surgery, University Hospital, Rouen, has carried out a prospective epidemiological survey of all nosocomial infections (pneumonia, SSI and CVCRI) since 1997. The study group included all consecutive patients who underwent cardiac surgery over a 10-year period from 1997 to 2007. A nested case-control study was conducted to identify the risk factors for SSI after CVCRI. Cases were patients with SSI after CVCRI and controls were randomized from patients who presented with CVCRI not followed by SSI. In total, 7557 patients were included and 133 SSIs (1.7%) were identified. The rate of superficial SSI was 0.7% [95% confidence interval (CI): 0.5-0.9] and of mediastinitis was 1.0% (95% CI: 0.8-1.2). Among the 133 cases of SSI, 12 (9.0%; 95% CI: 5.0-14.8) occurred after a CVCRI with identical micro-organisms. CVCRI [adjusted odds ratio (aOR): 5.2; 95% CI: 3.2-8.5], coronary artery bypass grafting (aOR: 2.9; 95% CI: 1.6-5.2), and obesity (aOR: 11.4; 95% CI: 1.0-130.1) were independent factors associated with SSI. The new finding of this study is that patients with CVCRI were 5.2 times more likely to develop SSI compared to patients without CVCRI.

Select spinal lesions reveal multiple ascending pathways in the rat conveying input from the male genitalia.

The specific white matter location of all the spinal pathways conveying penile input to the rostral medulla is not known. Our previous studies using rats demonstrated the loss of low but not high threshold penile inputs to medullary reticular formation (MRF) neurons after acute and chronic dorsal column (DC) lesions of the T8 spinal cord and loss of all penile inputs after lesioning the dorsal three-fifths of the cord. In the present study, select T8 lesions were made and terminal electrophysiological recordings were performed 45-60 days later in a limited portion of the nucleus reticularis gigantocellularis (Gi) and Gi pars alpha. Lesions included subtotal dorsal hemisections that spared only the lateral half of the dorsal portion of the lateral funiculus on one side, dorsal and over-dorsal hemisections, and subtotal transections that spared predominantly just the ventromedial white matter. Electrophysiological data for 448 single unit recordings obtained from 32 urethane-anaesthetized rats, when analysed in groups based upon histological lesion reconstructions, revealed (1) ascending bilateral projections in the dorsal, dorsolateral and ventrolateral white matter of the spinal cord conveying information from the male external genitalia to MRF, and (2) ascending bilateral projections in the ventrolateral white matter conveying information from the pelvic visceral organs (bladder, descending colon, urethra) to MRF. Multiple spinal pathways from the penis to the MRF may correspond to different functions, including those processing affective/pleasure/motivational, nociception, and mating-specific (such as for erection and ejaculation) inputs.

A quantitative method for assessing stages of the rat estrous cycle.

The impact of gender and/or hormone variations on a wide variety of neural functions makes the choice between studying males or females (or both) of a given species difficult. Although female rats are widely used experimentally, few studies control for the stage of estrus. More detailed information about how to distinguish the various stages of the estrous cycle is needed. For the present study, vaginal smears were obtained once a day and stained using an adaptation of the Papanicolaou (PAP) procedure. Images are provided of unstained "wet" samples and the corresponding PAP stained smears illustrating the cellular profile for each stage of the cycle as well as post-ovariectomy. The different cell populations across the cycle were quantified and ratios determined to show trends between the predominant and other cell types in each stage of the estrous cycle. Both stained and unstained images and cell quantification data provide valuable guidelines for distinguishing the stages of the estrous cycle.

Myocardial revascularization in patients with severe ischemic left ventricular dysfunction. Long term follow-up in 141 patients.

OBJECTIVES: The present study evaluates our experience with coronary bypass grafting in patients with EF < or =25%. Myocardial revascularization in this setting remains controversial because of concerns over operative mortality and morbidity and lack of functional and survival benefit. MATERIALS AND METHODS: One hundred and forty-one patients with coronary artery disease and left ventricular ejection fraction < or =25% underwent coronary artery bypass graft between January 1988 and December 1998. Mean age at operation was 63.3 years and 81.4% were male. The major indication for surgery was angina (114 patients, 80.8%). Ejection fraction (EF), left ventricular end diastolic pressure (LVEDP) and cardiac index (CI) were used to assess left ventricular function. The number of graft was 2.7+/-1.6/patient. Internal mammary artery was used in 119 patients (84.3%). Intra aortic balloon pump was placed preoperatively in 25 patients (17.7%). Five operative risk factors were associated with a higher mortality: emergency, female sex, LVEDP, CI and NYHA class IV. RESULTS: The operative mortality was 7% (10 patients). Left ventricular ejection fraction (assessed post operatively in 83 patients) improved from 22.2% preoperatively to 33.5% post operatively (P<0.001), mean end diastolic volume index fell from 98 to 83 ml/m(2) following surgery. Survival at 2, 5 and 7 years was respectively 84+/-3%, 70+/-4% and 50+/-5%. Two variables were associated with increased long term survival: congestive heart failure (NYHA class lower than IV (P=0.035) and cardiomegaly (P=0.04) CONCLUSION: In patients with left ventricular dysfunction, myocardial revascularization can be performed relatively safely with good medium term survival and improvement in quality of life and in left ventricular function. Coronary artery bypass graft may be offered to patients with impaired ventricular function, but careful patient selection and management when considering these patients for operation should assess potentially reversible dysfunction.

Co-expression of P2X receptor subunits on rat nodose neurons that bind the isolectin GS-I-B4.

Triple fluorescent histochemistry was used to describe the types of overlap in visceral sensory neurons (nodose ganglion) for the labeling of the isolectin B4 from Griffonia simplicifolia type one (GS-I-B4) and their immunoreactivity (IR) for two of the ATP receptor subunits (P2X1/3 or P2X2/3). The vast majority of nodose neurons expressed GS-I-B4-binding and most of these displayed P2X receptor IR. Most of the P2X-IR was co-expressed on these individual nodose neurons (P2X1/P2X3 or P2X2/P2X3). A very small subpopulation of neurons that were GS-I-B4 negative but P2X positive displayed a very high relative intensity of P2X3-IR. The functional role that these expression patterns play in visceral sensory processing is currently unclear.

[Acute traumatic rupture of the thoracic aorta and its branches. Results of surgical management]. / Ruptures traumatiques aiguës de l'aorte thoracique et de ses branches. Résultats du traitement chirurgical.

STUDY AIM: The aim of this retrospective study was to report a series of 102 patients with acute traumatic rupture of the thoracic aorta and its branches (TRA) and to evaluate long-term results. PATIENTS AND METHODS: From April 1977 to April 2000, 102 patients with RTA were admitted to our unit. Age ranged between 12 and 74 years (mean age: 33 years). Localisation was: ascending aorta (n = 3), aortic arch (n = 1), isthmus (n = 92), descending aorta (n = 1), innominate artery (n = 3), and left subclavian artery (n = 2). Associated injuries mainly included craniocerebral lesions (n = 76), rib fractures (n = 68), and thoracic (n = 38), and abdominal (n = 24) lesions. Average time between trauma and surgery was 37 hours. Aortography was used routinely for diagnosis. Five patients were inoperable; the procedure was delayed in three patients. In all but two patients with rupture of the isthmus, descending aorta and subclavian artery, the operation included venous arterial femorofemoral assistance. Rupture was partial in 37 patients (37 direct sutures), and complete in 55 patients (40 direct sutures). In two cases of left subclavian artery desinsertion, the operation included suture of the aortic tear and reimplantation of the artery. In patients with rupture of the ascending aorta and aortic arch, surgery was carried out under cardiopulmonary bypass with deep hypothermia for aortic arch rupture. Repair consisted of direct suture. In patients with rupture of the innominate artery, the lesion was treated under cardiopulmonary bypass by direct suture. In five cases, abdominal injuries required emergency procedure before aortic repair. RESULTS: Four patients died. No postoperative paraplegia occurred. The high morbidity rate was in relation to the associated injuries. Among the 93 survivors, the aortic clinical status was satisfactory in 91 patients (two patients were lost to follow-up). Two patients died from cancer and myocardial infarction 2 and 7 years later respectively. One patient had prosthetic sepsis and was reoperated on with homograft. Angiographic control by aortography (n = 60) and angioMRI (n = 22) was normal in 76 patients. There were five stenoses at the level of the prosthesis, four with a gradient < 20 mmHg and one with a gradient > 50 mmHg and one aneurysm at the level of the isthmus. These last two patients were reoperated on with good result. CONCLUSION: RTA remains a surgical emergency with multiple difficulties. Despite the development of new imaging modalities, angiography remains the gold standard for the work-up of these patients. Venous arterial femorofemoral assistance with a pump remains the best procedure in order to avoid paraplegia and vascular prosthesis implantation when possible. Endovascular stent graft insertion, although still under investigation, holds tremendous promise for non-surgical treatment of these patients.

Coarctation of the aorta in adults: surgical results and long-term follow-up.

BACKGROUND: The aim of this retrospective study was to determine the impact of coarctation surgical repair on arterial blood pressure in adults more than 20 years of age. METHODS: Thirty-five adults (23 men), mean age 28.1 +/- 5.7 years (range, 21 to 52 years), underwent coarctation surgical repair between 1977 and 1997. All patients had preoperative hypertension. Mean systolic blood pressure was 178 +/- 37 mm Hg (range, 110 to 230 mm Hg). Thirty-three patients were taking at least one hypertension medication at the time of operation. All patients had preoperative catheterization and angiography (mean gradient across the coarctation was 62 +/- 27 mm Hg [range, 32 to 130 mm Hg]). Operative technique was resection and end-to-end anastomosis for 30 patients, resection with Dacron (C. R. Bard, Haverhill, MA) graft for 4 patients, and a prosthetic bypass graft for 1 patient. There were no hospital deaths and no late morbidity. RESULTS: All patients were reviewed. Follow-up was 165 +/- 56 months (range, 25 to 240 months). Of the 35 patients with preoperative hypertension, 23 were normotensive (systolic blood pressure < or = 140 mm Hg, diastolic blood pressure < or = 90 mm Hg) with no medication. Twelve patients were receiving medication: 6 required single-drug therapy and 6 patients required two drugs. Exercise testing was performed at an average of 6 +/- 4 months after repair and revealed hypertensive response to exercise in 8 of the 23 patients who were normotensive at rest and without medication. There were no recoarctation or repeat operations. Six aortic valve diseases were observed: three aortic incompetences (two bicuspid valves) treated by two valve replacements and one Bentall procedure, and three aortic stenoses (two valve replacements). No patient had evidence of a cerebrovascular accident. CONCLUSIONS: Surgical repair of coarctation in adults has proved to be an effective procedure and significantly reduces arterial hypertension. However, long-term surveillance is mandatory and should include exercise testing to identify patients with potential hypertension.

Effects of acute and chronic midthoracic spinal cord injury on neural circuits for male sexual function. II. Descending pathways.

In normal animals, microstimulation of the medullary reticular formation (MRF) has two effects on efferent neurons in the motor branch of the pudendal nerve (PudM). MRF microstimulation depresses motoneuron reflex discharges (RD) elicited by dorsal nerve of the penis (DNP) stimulation and produces long latency sympathetic fiber responses (SFR). The midthoracic spinal location of these descending MRF-PudM projections was studied electrophysiologically using a variety of acute and chronic lesions. Chronic lesions, in 27 mature male rats, included dorsal (DHx) or lateral (LHx) hemisections or moderate/severe contusions (Cx) at spinal level T(8). Behavioral data (sexual reflex latency, bladder voiding) obtained throughout the recovery period revealed a significant impairment of urogenital function for the DHx and severe Cx groups of animals. Microstimulation-induced PudM-RDs and PudM-SFRs, obtained in terminal electrophysiological experiments 30 days postinjury in the same 27 rats (urethan-anesthetized), were tested for a combined total of 1,404 bilateral MRF sites. PudM-RD was obtained for LHx and moderate Cx groups of animals but not for DHx or severe Cx groups. PudM-SFRs were obtained for LHx, DHx (although significantly weakened) and moderate Cx groups but not for those having received either an over-DHx or a severe Cx injury. PudM responses also were tested for 6 MRF sites in six intact control rats both before and after various select acute spinal cord lesions. For MRF sites producing a robust PudM-RD and PudM-SFR, acute bilateral lesions confined to the dorsolateral quadrant (DLQ) eliminated the PudM-RD but failed to eliminate PudM-SFRs. A deeper lesion encompassing additional white matter located dorsally in the ventrolateral quadrant (VLQ) was necessary to eliminate PudM-SFRs. Overall, these electrophysiological results provide evidence for descending projections conveying information between MRF and the lower thoracic/lumbosacral male urogenital circuitry within the DLQ and the dorsal-most aspect of VLQ at the midthoracic level of spinal cord. The alterations of supraspinal projections observed after chronic injury are likely of important clinical significance for functional recovery in cases of clinically incomplete spinal cord injury at midthoracic spinal cord.

Brainstem microstimulation activates sympathetic fibers in pudendal nerve motor branch.

A bilateral spino-bulbo-spinal circuit conveys information from/to the male urogenital tract and perineal muscles. This is the first electrophysiological report of another descending pathway, one which conveys output from the medullary reticular formation (MRF) to activate postganglionic sympathetic fibers contained within the motor branch of the pudendal nerve (PudM). In anesthetized rats, long latency (> 150 ms) discharges were elicited in the PudM following ipsilateral or contralateral microstimulation of the MRF. These firing bursts were not observed in rats after sectioning the lower lumbar sympathetic trunk. The most robust activation was observed when neurons in or near the lateral paragigantocellular reticular nucleus were microstimulated bilaterally. Urogenital dysfunction that occurs following severe spinal cord injury probably results from disrupting these and other supraspinal circuits.

Effects of acute and chronic midthoracic spinal cord injury on neural circuits for male sexual function. I. Ascending pathways.

Normal male reproductive function, particularly ejaculation, requires the integrity of urogenital sensory input and its ascending spinal projections. After midthoracic chronic spinal cord injury, sexual dysfunction occurs in both rats and humans. Neurons in the medullary reticular formation (MRF) are involved in the processing of bilaterally convergent sensory inputs from multiple cutaneous, mucocutaneous, and visceral regions of the body, including the penis and male urogenital tract. A variety of acute and chronic lesions were used to determine the midthoracic location of ascending spinal pathways conveying sensory input from the penis and male urogenital tract to MRF. A total of 371 single neurons were recorded in the MRF of 34 urethan-anesthetized mature male rats. Twenty-seven rats received a chronic T8 dorsal (DHx) or lateral (LHx) hemisection or contusion (Cx) injury 30 days before the terminal electrophysiological experiments. In addition, nine dorsal nerve of the penis (DNP)-responsive MRF neurons in seven intact control animals were tested completely both before and after various select acute spinal cord lesions. The chronic lesion data indicate that low and high threshold input from the penis (mucocutaneous) and male urogenital tract (visceral) ascend bilaterally within the dorsal quadrant at T8 as opposed to high threshold input from the hindpaws (cutaneous), which ascends unilaterally in the ventrolateral quadrant (VLQ). The acute lesion data indicate that the low-threshold information conveyed from the penis and male urogenital tract ascends in the dorsal columns, as opposed to the high-threshold nociceptive inputs that ascend bilaterally in the dorsolateral quadrant (DLQ). These results, as well as previous data on ascending projections from female reproductive organs within the dorsal columns and DLQ to other caudal brain stem nuclei, provide evidence for ascending pathways conveying nociceptive information centrally via the DLQ. This spinal gray-DLQ pathway(s) conveying information from mucocutaneous/pelvic/visceral territories therefore differs from the traditionally recognized spinal gray-VLQ pathway(s), which is known to convey nociceptive information from cutaneous regions of the body.

Changes in neuronal receptive field characteristics in caudal brain stem following chronic spinal cord injury.

Chronic spinal cord injury pain is poorly understood and, thus, not effectively relieved by traditional treatments. In the present study, a variety of partial, severe and sham chronic spinal lesions were made in 31 male rats at spinal level T8. During routine care/handling and brief behavioral testing of the animals throughout the 30-day recovery period, the majority of those with severe contusion injuries (verified histologically) showed signs of mechanical hypersensitivity on the dorsolateral trunk just rostral to the level of injury (i.e., upper thoracic territory). Terminal electrophysiological experiments were performed on all rats (urethane anesthesia). Single unit recordings were made at two supraspinal locations within the caudal brainstem, the nucleus reticularis gigantocellularis and nucleus reticularis gigantocellularis pars alpha. Neurons in these areas normally receive bilateral nociceptive somatovisceral inputs from many parts of the body. Seventy-three percent of the animals with severe contusion injuries developed novel low-threshold neuronal responses to stimulation of the dorsolateral trunk (upper thoracic territory). This amount was significantly greater than for animals with more moderate spinal lesions (dorsal or lateral hemisection; 29% and 25%, respectively) or sham controls (0%). These data suggest (1) that the spinal contusion is a reliable model for studies of the neural mechanisms that underly central spinal cord injury-related pain and (2) that the caudal brainstem is one supraspinal location where neurons undergo significant changes in responsiveness following severe chronic spinal cord injury. The observed plasticity is likely part of the central reorganization producing the multitude of sensory disturbances that surface following spinal cord injury.

Anodally focused polarization of peripheral nerve allows discrimination of myelinated and unmyelinated fiber input to brainstem nuclei.

We investigated the ability of a novel direct current (DC) polarization technique to block selectively the conduction in peripheral myelinated nerve fibers and allowing propagation in only unmyelinated fibers. In anesthetized adult rats, distal branches of the sciatic nerve (caudal cutaneous sural and tibial nerves) were exposed for electrical stimulation of A- and C-fibers. Two specially fabricated trough electrodes of different size and surface area were placed onto the sciatic nerve. Through these proximal electrodes a controlled ramped DC was timed to coincide with the arrival of A- and C-fiber action potentials, evoked electrically at the distal nerves or naturally from the foot or ankle, with the intent of blocking propagation in A-fibers while allowing C-fiber throughput. Neuronal recordings were made both peripherally (proximal sciatic nerve fascicles or L5 dorsal roots) and centrally (single cells in the nucleus gracilis or nucleus reticularis gigantocellularis). The DC polarization was shown to block conduction in myelinated A-fibers effectively, while allowing conduction in the unmyelinated C-fibers, without activation of fibers via the DC polarization itself. This was dependent upon the following factors: electrode polarity, onset rate of polarization, peak amplitude of polarization, distance between polarizing electrodes, size difference between polarizing electrodes, and gross nerve size. These experiments demonstrate that anodally focused DC polarization, applied utilizing two trough electrodes of different sizes, is capable of effectively, reversibly, and reproducibly blocking conduction in myelinated A-fibers evoked either electrically or naturally, while still allowing conduction to occur in the unmyelinated C-fiber population. In the context of experimental usage, we have demonstrated blocking of low-threshold A-fiber, but not C-fiber, mediated inputs to the caudal brainstem. This technique should find wide application in studies involving the processing of information conveyed centrally by the unmyelinated C-fiber afferent population, including discriminating afferent responses to peripheral stimuli, the role of C-fiber input in reflex activity, and the plasticity following injury or other manipulations.

Brainstem microstimulation differentially inhibits pudendal motoneuron reflex inputs.

Sensory information from the genitourinary tract is transmitted to perineal muscle reflex circuits in the spinal cord and to the medullary reticular formation (MRF). This is the first report of a functional descending connection between neurons in the MRF and sensory inputs of the pudendal motoneuron reflex circuitry. In anesthetized rats, microstimulation of the MRF produced a decrease in amplitude and increase in latency of pudendal motoneuron reflex discharges (PMRD) elicited by stimulation of the dorsal nerve of the penis. No effects on pelvic nerve-elicited PMRD were found. The most robust reflex depression was observed when the lateral paragigantocellular reticular nucleus was microstimulated bilaterally. Reproductive abnormalities that occur following severe spinal cord injury probably result from disruption of these descending connections.

Urgent surgical repair of postinfarction ventricular septal rupture: early and late outcome.

AIM: This retrospective analysis focuses on predictive factors of operative mortality and long-term survival after surgical repair of postinfarction ventricular septal rupture (VSR). METHODS: Sixty-seven patients (43 males, 24 females) with VSR underwent surgical repair between December 1977 and December 1995. The site of the rupture was anterior in 44 patients and posterior in 23. The mean interval between myocardial infarction (MI) and VSR was 3.6+/-4.1 days. Clinical condition on admission was critical in 63 patients (49 in cardiogenic shock). An intra-aortic balloon pump was inserted preoperatively in 54 patients. RESULTS: Operative mortality was 25% (17 patients). The main cause of death was cardiac failure. Factors influencing early deaths in univariate analysis were preoperative hemodynamic status (cardiogenic shock present in 30%; absent in 8%; p = 0.001), the location of the MI (anterior in 11.6%, posterior in 45.4%), the interval between infarction and surgery (<1 week was 33%, >1 week was 6.2%), and the response to initial active therapy. All patients were available for follow-up. The actuarial survival rates at 1 and 5 years are 74.6%+/-5.3% and 66.2%+/-6.2%, respectively. There were 12 late deaths and 40% were cardiac related. Two patients presented residual VSD (one reoperation). The left ventricular ejection fraction (LVEF) was mildly impaired in 9 patients. Three patients had moderate mitral insufficiency and two had moderate tricuspid insufficiency. CONCLUSION: Repair of the postinfarction VSR remains a challenge. Improvement should be rendered possible by optimizing techniques. Postoperative morbidity is high, and these patients require intensive hospital resources. The late results have been satisfactory.