PENILE ANATOMY UNDER THE PUBIC ARCH: RECONSTRUCTIVE IMPLICATIONS

PURPOSE: We have previously defined the anatomy of the neurovascular bundle in the normal and hypospadiac penis. These studies were based on analysis of the fetal penis distal to the pubic arch without total inclusion of the crural bodies. To our knowledge the neuroanatomy beneath the pubic arch has not been well described. We defined the nerve distribution under the pubic arch and the relationship of the nerves to the crural bodies, corporeal bodies and urethra of the penis. MATERIALS AND METHODS: Eight normal human fetal penile specimens (at 17.5 to 29 weeks of gestation and 1 hypospadiac specimen at 32 weeks were serially sectioned and stained with Masson's trichrome, and the neuronal markers protein gene product 9.5 and S-100. These specimens were unique in that they contained the whole penis from the glans to the crural bodies beneath the pubic arch. Older specimens were decalcified before fixation. Computer reconstruction with commercially available graphics software allowed 3-dimensional analysis of the nerves and crural bodies in relation to the pubic arch and surrounding structures. RESULTS: The nerves of the penile shaft and glans surrounded the corporeal bodies, extending from the junction of the urethral spongiosum to the classic 11 and 1 o'clock positions with a paucity of nerves at the 12 o'clock position in the dorsal midline. Beneath the pubic arch the nerves to the penis were an extension of the dorsal neurovascular bundle of the prostate. The nerves formed 2 bundles following a path just under the pubic arch in close proximity to the bone, superior to the urethra and medial to the origin of the crural bodies. The nerve bundles joined the corporeal bodies at the proximal origin, where the 2 crural bodies fused together. At this point perforating branches into the corporeal bodies from the cavernous nerves were documented. As the dorsal nerves joined the dorsal aspect of the corporeal bodies, they immediately began to fan out along the surface of the corporeal tissue to the junction of the urethral spongiosum. Three-dimensional reconstruction showed the relationship of the nerves to the pubic arch and urethra in multiple views. CONCLUSIONS: A precise understanding of penile anatomy beneath the pubic arch and at the origin of the crural bodies is important for preserving neuronal structures. This anatomy is especially germane in children undergoing posterior urethral reconstruction secondary to trauma, intersex requiring feminizing genitoplasty and severe hypospadias.     

Induction of platelet aggregation after a direct physical interaction with diesel exhaust particles

Summary. Background: There is a proven link between exposure to traffic‐derived particulate air pollution and the incidence of platelet‐driven cardiovascular diseases. It is suggested that inhalation of small, nanosized particles increases cardiovascular risk via toxicological and inflammatory processes and translocation of nanoparticles into the bloodstream has been shown in experimental models. We therefore investigated the ability of diesel exhaust particles (DEP) to interact physically and functionally with platelets. Methods: The interaction of DEP and carbon black (CB) with platelets was examined by transmission electron microscopy (TEM), whereas the functional consequences of exposure were assessed by measuring in vitro and in vivo platelet aggregation via established methods. Results: Both DEP and CB were internalized and seen in proximity with the open canalicular system in platelets. DEP induced platelet aggregation in vitro whereas CB had no effect. DEP induced Ca²⁺ release, dense granule secretion and surface P‐selectin expression, but not toxicologic membrane disruption. Low concentrations of DEP potentiated agonist‐induced platelet aggregation in vitro and in vivo. Conclusions: DEP associate physically with platelets in parallel with a Ca²⁺‐mediated aggregation response displaying the conventional features of agonist‐induced aggregation. The ability of DEP to enhance the aggregation response to platelet stimuli would be expected to increase the incidence of platelet‐driven cardiovascular events should they be inhaled and translocate into the blood. This study provides a potential mechanism for the increased thrombotic risk associated with exposure to ambient particulate air pollution.     

Atrial natriuretic peptide in alcoholic cirrhosis

Sodium retention in cirrhosis could result from a deficiency of atrial natriuretic peptide (ANP) or end-organ resistance to ANP. Venous levels of α-human ANP (αhANP) measured in 19 alcoholic cirrhotics by radio-immunoassay were in the higher end of the normal range (29.7 pg/ml, s.d. = 17.2) and tended to increase with development of ascites or varices. Arterial levels of αhANP were not related to right atrial pressure but were related inversely to pulse rate. There was significant splanchnic (mean = 37.2%, s.d. = 19.5) and non-splanchnic clearance (mean = 30.3%, s.d. = 17.1) of αhANP. The percentage extraction of αhANP across the splanchnic bed (%E ANP splanchnic) was not related to portal pressure, effective hepatic plasma flow or degree of intrahepatic shunting. The %E ANP splanchnic increased as functional liver cell mass (antipyrine clearance) decreased (r= 0.592, P= 0.034). Despite increased splanchnic clearance, αhANP levels increased with a fall in functional liver cell mass presumably due to increased release. Renal sodium retention in cirrhosis does not involve a deficiency of αhANP but increased end-organ resistance needs to be excluded.     

Mortality and two year outcome of infants of birthweight 500-1500 g: relationship with neonatal cerebral ultrasound data

Cranial ultrasounds were performed on 218 (96%) of 227 liveborn infants of birthweight 500-1500 g delivered in the Royal Women's Hospital, Melbourne, Australia, in an 18-month period concluding in March 1982. Seventy-two (31.7%) of the children died; 28 children (38.9%) had cerebroventricular haemorrhage, 35 (48.6%) showed no bleeding and there were nine (12.5%) with no data. Paired necropsy and ultrasound data were congruent in 22 (88%) of 25 children. One hundred and forty-eight (95.5%) of 155 survivors were seen at 2 years of age. Forty-one (28%) had cerebroventricular haemorrhage; nine children (6%) had both ventricular dilatation and haemorrhage and two had ventricular dilatation alone. Apart from a marginal advance in gestation and higher number of immigrant and less educated mothers in children without cerebroventricular haemorrhage, all other perinatal, biographical and social variables between those with haemorrhage and those without were similar. The major handicap rate overall was 14.2% (21 patients). The children with cerebroventricular haemorrhage had a trend for greater prevalence of handicap and lower mean Bayley psychological scores. This was even more evident with ventricular dilatation being present. Of children with major handicap 57.1% (12/21) had normal serial ultrasound findings during their primary hospitalization. Major handicap occurred in 15% (3/20) of children with grade 1 haemorrhage, 23.5% (4/17) with grade 2 or 3 bleeds and 25% (1/4) of those with grade 4 haemorrhage. Laterality of cerebral palsy did not correlate with ultrasound findings. Ultrasound findings did not improve statistical prediction of deaths or major handicap.     

BASAL AND SALINE-STIMULATED LEVELS OF PLASMA ATRIAL NATRIURETIC FACTOR IN ACROMEGALY

We have studied plasma ANF before and after a 4-h intravenous infusion of normal saline in eight subjects with active acromegaly and in eight age and sex-matched control subjects. Plasma ANF, serum aldosterone and blood pressure were measured basally and after 2 and 4 h and plasma renin activity basally and after 4 h. Basal plasma ANF was similar in each group (4.4 +/- 1.5 pmol/l (mean +/- SEM) in acromegalic subjects and 5.3 +/- 0.7 pmol/l in controls NS). Plasma ANF did not rise significantly after saline in the acromegalic group (2-h value, 5.9 +/- 0.9; 4-h value, 5.1 +/- 0.9 pmol/l) but did rise significantly in the control group (2-h value, 8.9 +/- 1.9; 4-h value 9.5 +/- 1.3 pmol/l, both values P less than 0.05 vs basal level). The 4-h ANF value was significantly higher in the control group than in the acromegalic group (P less than 0.05). Basal and stimulated serum aldosterone values were similar in the two groups. Plasma renin activity suppressed to a lesser extent in the acromegalic group after 4 h. The facts that basal plasma ANF was not raised in acromegalic subjects and did not respond to saline stimulation demonstrate that an abnormality of ANF control may be an important factor in the aetiology of the expanded sodium status of patients with acromegaly and hence may contribute to the hypertension seen in patients with growth hormone excess.     

Total intravenous anaesthesia with etomidate-fentanyl

A total intravenous anaesthetic technique using etomidate, fentanyl and neuromuscular blocking drugs with artificial ventilation of the lungs has been used in 90 patients undergoing elective general and gynaecological surgery. A two-step schedule was used, based on a pharmacokinetic model for rapidly eliminated, intravenously administered drugs. Etomidate 100 micrograms/kg/minute with fentanyl 1 microgram/kg/minute were given for 10 minutes, followed by a maintenance dose at a rate of one-tenth this amount. Concurrent evaluation of the technique led to variations in the adjuvant drugs used (atropine, droperidol and neuromuscular blocking agent). The basic dose schedule provided adequate surgical anaesthesia for 76% of patients (although dose adjustments were used in the remainder), with recovery times of 10 minutes or less in 57% of patients. No further opiate analgesia was needed in 40% of patients postoperatively. Those patients given atropine intravenously prior to induction had a significantly lower incidence of nausea and vomiting postoperatively.     

Comparison of Corynebacterium Parvum With Freund's Complete Adjuvant as a Potentiator of the Immune Response To β-Human Chorionic Gonadotropin Linked to Tetanus Toxoid

ABSTRACT: Corynebacterium parvum was compared with Freund's complete adjuvant (FCA) for potentiation of the rabbit immune response to β-human chorionic gonadotropin linked to tetanus toxoid (β-hCG-TT). With each adjuvant, antibodies to hCG were detected using passive hemagglutination. Higher antibody titers were produced by FCA-treated animals. The ability of antisera to β-hCG-TT to neutralize the biological action of native hCG was determined by the rat uterine weight assay. Anti-β-hCG-TT sera from C. parvum-treated rabbits were not significantly different (p > 0.10) from FCA potentiated anti-β-hCG-TT sera in neutralizing hCG-induced uterine weight gain. C. parvum has potential for future application in active immunization studies of fertility regulation.     

Low Energy Endocardial Cardioversion of Atrial Arrhythmias in Humans

We assessed the feasibility of low energy endocardial defibrillation in patients with atrial fibrillation or atrial flutter who had failed a trial of pharmacological reversion with amiodarone. Low energy endocardial defibrillation under general anesthesia was attempted in 9 patients, 5 with atrial flutter and 4 with atrial fibrillation (median duration of arrhythmia 3.75 months). Two large surface area endocardial leads were introduced percutaneousiy and sited in the right atrial appendage and at the right ventricular apex. A cutaneous patch electrode was placed on the left thorax. Biphasic shocks synchronized to the ventricular electrogram were used to terminate atrial arrhythmias. Three electrode configurations were evaluated in the following sequence at each energy level: atrial cathode to ventricular anode; ventricular cathode to atrial anode; atrial cathode to a combined ventricular and cutaneous anode. If endocardial defibrillation failed (0.5–10 J), transthoracic defibrillation using 200 joules followed by 360 joules, if required, was performed. Endocardial defibrillation was successful in all five patients with atrial flutter (0.5 J, 1.0 J, 1.0 J, 4.0 J, and 10,0 J) but in only one patient with atrial fibrillation (10 J). On no occasion did successful defibrillation occur with one configuration when it had failed with an alternate configuration at that particular energy level. Ventricular fibrillation did not occur, and there were no other significant complications. Low energy endocardial defibrillation is feasible in patients with atrial flutter using large surface area electrodes. Although the success rate of atrial defibrillation was low, further work is required, particularly in patients with more recent onset of the arrhythmia and using a right to left electrode configuration.     

Asystolic Cardiac Arrest During Head-Up Tilt Test: Incidence and Therapeutic Implications

Occasionally, the cardioinhibitory response may be profond during tilt induced syncope. Whether this response is associated with more severe symptoms or predicts a poor response to pharmacotherapy remains controversial. The aim of this study was to characterize patients with vasovagally mediated asystole occurring during head-up tilt test and to evaluate the respective interests of sequential pacing and β-blockers to treat them. We performed 60° tilt testing in 179 consecutive patients with unexplained syncope (91 women and 88 men, age 36.6 ± 20.1 years). Asystole was defined as a ventricular pause > 5 seconds. All patients with tilt induced asystole received therapy with either β-blockers or sequential pacing, the efficacy of which was evaluated with serial tilt tests. Of 77 patients with positive tilt test, 10 developed syncope related to asystole (mean duration 11.9 ± 4.9 s), 2 with spontaneous recovery, and 8 with seizures needing a brief cardiopulmonary resuscitation. When compared with patients without asystole, asystolic patients had more severe symptoms (seizures: 6/10 vs 9/67, P = 0.05, injury: 9/10 vs 27/67, P = 0.0048). In the first six patients in whom cardiac pacing was considered, syncope or presyncope still occurred despite atrioventricular pacing at 45 beats/min. Five of these 6 patients, as well as the remaining 4 asystolic patients, were tilted with β-biockers: 3 patients became tilt-negative; 3 were significantly improved; and 3 did not respond. During follow-up (mean 22.7 ± 11.7 months) with every patient taking β-blockers and seven having a permanent pacemaker, no syncopal recurrence was observed. Tilt-induced asystole that may require resuscitative maneuvers occurs especially in patients with a history of seizures or injury. Therapy with β-blockers is often effective to prevent induction of syncope as well as recurrences.     

Basal Exit Site of Clinical Ventricular Tachycardia is an Independent Predictor of Antitachycardia Pacing Failure in Implantable Cardioverter‐Defibrillators Recipients

Background: Little is known about predictors of antitachycardia pacing (ATP) failure in implantable cardioverter defibrillator (ICD) recipients. Distance between the stimulation site and the ventricular tachycardia (VT) site of origin may critically affect ATP effectiveness. We hypothesized that ATP may be less effective in ICD patients who had basal VT than in those who had apical VT. Methods: We reviewed data from 52 patients with sustained monomorphic VT and left ventricular disease referred for ICD implantation. ATP was delivered exclusively at the right ventricular apex. The clinical VTs site of origin (basal, midventricular, or apical) was determined in each patient, using 12‐lead electrocardiogram. VTs episodes treated with ATP during the 1‐year follow‐up were studied. ATP success rate (%), defined as the ratio between the number of successful ATP sequences and the number of delivered ATP sequences, was determined in each patient. Results: VT exit site was apical in 19 patients (36%), basal in 18 patients (35%), and midventricular in 15 patients (29%). In those 52 patients, 1,393 ATP sequences, delivered to treat 761 VT episodes, were analyzed. ATP success rate was found to be associated with the VT site of origin (median [interquartile range]): basal (33%[11–67]), midventricular (50%[37–100]), apical (100%[41–100]) (P = 0.027). Multivariate analysis identified basal VT site of origin as an independent predictor of ATP failure (P = 0.023). Conclusion: ATP is less effective in ICD patients who had basal VT than in those who had apical VT before ICD implantation. (PACE 2012; 35:1209–1216)