Percutaneous central venous catheterization via the great saphenous vein in neonates

In 44 neonates (mean birthweight 1207 g and mean gestational age 30.0 weeks), very small central venous catheters were percutaneously inserted via the great saphenous vein on 46 occasions. Catheter-related complications such as catheter blockages in 17 (37%), edema in a unilateral leg in three (6%), and mechanical disruption in two (4%) were noted. Although two of the neonates were found to have bacteremia and five neonates died, none were catheter related. The optimal length of catheter insertion (Y) from the great saphenous vein at the level of the medial maleollus to the inferior vena cava at T9 and L3 was calculated by regression equations utilizing total body length (X). Radiographs taken with extended and flexed leg postures revealed that the catheter tips were retracted with extension of the lower extremities and the degree of displacement ranged from 1 to 4 (mean 2.7) vertebral levels. Because this movement might cause migration into veins that connect to the inferior vena cava, the catheter tip should be located between T9 and L3, except at the renal vein junction. Percutaneous central venous catheterization via the great saphenous vein is safe and useful. Regression equations provided for rapid estimation of the optimal length of insertion.     

Frequency- and Time-Domain Analysis of P Wave in Patients with Paroxysmal Atrial Fibrillation

We investigated the usefulness of the time- and frequency-domain analysis of the P wave triggered signal-averaged ECG (P-SAECG) for detecting patients with paroxysmal atrial fibrillation (Paf). In previous studies, the usefulness of the time domain of the P-SAECG to detect patients with Paf was described but that of the frequency domain is unknown. We analyzed the P-SAECG in the time and frequency domain in 23 patients with Paf and 19 controls. The 32-unipolar chest lead ECGs and the standard bipolar limb lead ECGs were obtained. The time-domain analysis showed that the filtered P duration (fPd) was significantly longer (P < 0.01) in patients with Paf than controls: the predictive accuracy of Paf with fPd > 120 ms was 69%. The frequency domain analysis showed that the area ratio of power spectrum area of 0–20 Hz to 20–100 Hz (AR20) was significantly higher (P < 0.01) and the magnitude ratio at 30 Hz (%Mag.30) calculated by dividing the magnitude at 30 Hz by the maximal magnitude was significantly (P < 0.01) lower in patients with Paf than controls in the left lateral chest leads. The predictive accuracy of Paf with AR20 ≥ 1.5 and that with %Mag.30 < 40% was 83% and 73%, respectively. Our results indicate that the frequency-domain analysis of P waves in lateral leads is useful as is the time-domain analysis to detect patients with Paf. The AR20 ≥ 1.5 and %Mag.30 < 40% provides accurate predictability of Paf.     

Nocturnal enuresis and overactive bladder in children: An epidemiological study

AIMS: To investigate the prevalence and characteristics of nocturnal enuresis (NE) and to examine the prevalence of overactive bladder (OAB) symptoms in primary schoolchildren. METHODS: After conducting an anonymous questionnaire survey about voiding habits and bowel habits in primary schoolchildren, a total of 6917 schoolchildren belonging to 11 primary schools were randomly enrolled in the survey. According to the International Continence Society, we defined NE as any involuntary loss of urine during sleep, occurring more frequently than once per month. Children with NE were subdivided into two groups, monosymptomatic NE (MNE) and enuretic syndrome (ES). To evaluate the characteristic differences of MNE and ES, we assessed the relationships between NE and voiding habits, and episodes of cystitis and constipation. Overactive bladder was defined as increased daytime frequency and/or urge urinary incontinence, and its prevalence was investigated. RESULTS: The response rate to the questionnaire was 76.4%. The prevalence of NE was 5.9% and was inversely related to increasing age. Monosymptomatic NE comprised 59.4% of NE cases. The annual spontaneous resolution rate of MNE was higher than that of ES. Increased daytime frequency, a history of cystitis and infrequent bowel habits were not related to MNE, but were significantly related to ES. The prevalence of OAB was 17.8%. Children with a history of cystitis had a significantly higher rate of OAB than children without it. CONCLUSIONS: Overall, NE and OAB were detected in 5.9% and 17.8% of primary schoolchildren, respectively. The link between NE and OAB symptoms, urinary tract infections and constipation deserves more attention.     

Comparison of the Effects of Regional Ischemia and Hyperkalemia on the Membrane Action Potentials of the In Situ Pig Heart

APD During Ischemia. Introduction: This study was designed to determine the role of increased extracellular potassium [K⁺]_e on action potential duration (APD) in the in situ porcine heart during acute regional no-flow ischemia.
Methods and Results: In open chest, anesthetized swine, an arterial shunt from the carotid artery to the mid-left anterior descending coronary artery was created through which a solution of KCl was infused to raise [K⁺]_e, Myocardial [K⁺]_e, was determined by potassium-sensitive electrodes, and transmembrane action potential was recorded by floating glass microelectrode. During the first 2 minutes of ischemia, APD at 90% repolarization (APD₉₀) lengthened by 31.2 ± 1.1 msec (P < 0.05). The comparable increase in [K⁺]_e alone shortened APD₉₀, During the next 6 minutes of ischemia. [K⁺]_e, rose to 11.3 ± 0.3 mM and APD₉₀, showed a decrease. However, the comparable increase in |K⁺]_e, by infusion of KCl caused further shortening of APD₉₀, at similar levels of [K⁺]_e.
Conclusions: Acutely ischemic myocardium showed a brief increase in APD₉₀, during the first 2 minutes of ischemia, followed by a fall in APD₉₀, after 2 minutes of ischemia, but the shortening is less than anticipated by the rise in [K⁺]_e. Thus, we hypothesize that other component(s) of ischemia may inhibit action potential repolarization.     

Electrostimulation of sympathetic nerve fibers during nerve-sparing laparoscopic retroperitoneal lymph node dissection in testicular tumor

A long-handled pair of electrodes with sufficient length to allow stimulation during laparoscopic retroperitoneal lymph node dissection (RPLND) was designed at our institute. We clinically utilized this electrode in the treatment of a 37-year-old patient with testicular tumor who underwent right orchidectomy and nerve-sparing laparoscopic RPLND. During laparoscopic RPLND, sympathetic nerve fibers relevant to ejaculation were electrically stimulated and changes in pressure at the bladder neck were observed. Nerve preservation was confirmed by increased pressure at the bladder neck and ejaculation immediately after the electrostimulation. The application of laparoscopic electrostimulation may become widespread, particularly since it meets the increasing demand for minimally invasive surgery.     

Gastric lipoma successfully treated by endoscopic unroofing

A 64‐year‐old Japanese man was diagnosed with a tumor of the stomach. From the findings of an upper gastrointestinal endoscopy, computed tomography scan and endoscopic ultrasonography, the tumor was suggestive of a gastric lipoma. He was successfully treated by an endoscopic unroofing technique. There remained residual tumor just after unroofing, but it disappeared a month later. There remained only a scar and there has been no recurrence.     

Gastric diverticulum preoperatively diagnosed as one of two left adrenal adenomas

A 47-year-old man was diagnosed with primary aldosteronism due to two left adrenal adenomas, suggested on computed tomography (CT) to be located at the upper and lower adrenal portion. However, adosterol scintigraphy revealed negligible uptake at the upper portion of the left adrenal. Laparoscopic left adrenalectomy was performed, but macroscopic examination of the specimen revealed only one adrenal tumor. Continued surgical exploration detected another mass between the spleen and the stomach, which was demonstrated to be continuous with the stomach and was eventually diagnosed as a gastric diverticulum. Postoperatively, aldosteronism resolved and repeat CT revealed staining of the adrenal pseudotumor when oral contrast was administered. Since organs located near the adrenals can simulate adrenal tumors, caution must be exercised in interpreting suprarenal masses on CT. To our knowledge, this is the first reported case of concurrent pseudotumor and true tumor of the ipsilateral adrenal.     

Novel C-terminal gastrin antagonists Synthesis and biological activity

The C-terminal tetrapeptide, Trp-Met-Asp-Phe-NH₂, is a full agonist of gastrin, but des-Phe analogues, including Boc-Trp-Met-Asp-NH₂, are antagonists. To ascertain the minimum structural requirement for an antagonist, we used conventional solution phase methodology to synthesize analogues with further modifications including removal of the α-amino group of Trp, conversion of the indole to a phenyl ring, and methylation of amide bonds. These analogues were tested for their effect on pentagastrin-stimulated acid release in dogs surgically prepared with a gastric fistula. When infused intravenously at a dose of 20pmolkg^?1h^?1, the peptides significantly inhibited acid secretion. The extent of inhibition ranged from 12% to 60%. Thus, tripeptide analogues based on the C-terminal sequence of gastrin act as potent and specific antagonists of gastrin-stimulated acid secretion.