Control of Optical Transitions with Magnetic Fields in Weakly Bound Molecules.

In weakly bound diatomic molecules, energy levels are closely spaced and thus more susceptible to mixing by magnetic fields than in the constituent atoms. We use this effect to control the strengths of forbidden optical transitions in (88)Sr2 over 5 orders of magnitude with modest fields by taking advantage of the intercombination-line threshold. The physics behind this remarkable tunability is accurately explained with both a simple model and quantum chemistry calculations, and suggests new possibilities for molecular clocks. We show how mixed quantization in an optical lattice can simplify molecular spectroscopy. Furthermore, our observation of formerly inaccessible f-parity excited states offers an avenue for improving theoretical models of divalent-atom dimers.

Thermometry via light shifts in optical lattices.

For atoms or molecules in optical lattices, conventional thermometry methods are often unsuitable due to low particle numbers or a lack of cycling transitions. However, a differential spectroscopic light shift can map temperature onto the line shape with a low sensitivity to trap anharmonicity. We study narrow molecular transitions to demonstrate precise frequency-based lattice thermometry, as well as carrier cooling. This approach should be applicable down to nanokelvin temperatures. We also discuss how the thermal light shift can affect the accuracy of optical lattice clocks.

Small-sized dichroic atomic vapor laser lock.

Two, lightweight diode laser frequency stabilization systems designed for experiments in the field are described. A significant reduction in size and weight in both models supports the further miniaturization of measurement devices in the field. Similar to a previous design, magnetic field lines are contained within a magnetic shield enclosing permanent magnets and a Rb cell, so that these dichroic atomic vapor laser lock (DAVLL) systems may be used for magnetically sensitive instruments. The mini-DAVLL system (49 mm long) uses a vapor cell (20 mm long) and does not require cell heaters. An even smaller micro-DAVLL system (9 mm long) uses a microfabricated cell (3 mm square) and requires heaters. These new systems show no degradation in performance with regard to previous designs while considerably reducing dimensions.

Vitamin K deficiency during the perinatal and infantile period.

Coagulation-related plasma proteins develop slowly during the gestational period and are still markedly lower than normal at birth. Great interest exists in the status of the vitamin K-dependent procoagulant factors (factors II, VII, IX and X) because a number of healthy newborns develop postpartum a bleeding tendency that is due to vitamin K deficiency. The most serious cases involve intracranial bleeding with convulsions, coma and potential death. Typically, these infants have markedly prolonged prothrombin times that shorten following the administration of vitamin K. A common feature of these infants is that they are breast-fed, although other factors, especially hepatobiliary diseases, contribute to this disorder. Vitamin K deficiency bleeding can develop as early as in the first 24 hours after birth, but most infants are diagnosed between days 2 and 7 postpartum. Late forms (> 1 week and up to 6 months) are also noted. This deficiency can be compensated for by prophylactically administering vitamin K to the newborns or by bottle-feeding. Although vitamin K2 may pass in small quantities through the placenta, it is insufficient to make up for the deficit. The first dose of vitamin K can also be given orally to the newborn after one or two regular feedings, and the second dose can be administered upon discharge from the hospital. A problem that remains to be solved is the late development of vitamin K deficiency in spite of prophylaxis at birth.

Is a new biofeedback therapy effective for fecal incontinence in patients who have anorectal malformations?

PURPOSE: The authors devised computerized equipment for use in the biofeedback therapy in the management of fecal continence after surgery for anorectal malformations. METHODS: The therapy was used for two to eight sessions in 14 children (11 who had high-type anomalies and three who had intermediate-type anomalies). The ages ranged 5 to 14 years. A control group of 17 children, aged 5 to 11 years, who had encopresis, was also treated with the same biofeedback therapy. RESULTS: Clinical improvement was noted in 5 of the 14 (36%) children who had fecal incontinence, and in 15 of the 17 children (88%) who had encopresis. Both in patients who had fecal incontinence and in those who had encopresis, anal resting pressures were not affected by biofeedback therapy. Furthermore, the anal resting pressure in children who had fecal incontinence was significantly lower than that in children who had encopresis. However, anorectal manometry showed that the biofeedback therapy improved voluntary sphincter function and rectal sensation in both groups. CONCLUSION: Biofeedback therapy appears to be effective in most children who have encopresis whose sphincter function is intact, and in some children who have fecal incontinence after surgery for anorectal malformations.

A comparison of anal endosonography with electromyography and manometry in high and intermediate anorectal anomalies.

Anal endosonography, electromyography (EMG) of the external anal sphincter (EAS), and manometry of the internal anal sphincter (IAS) were performed in 15 patients with anorectal anomalies (10 with high and five with intermediate anomalies), ranging in age from 8 to 18 years. The anal endosonographic findings were compared with those for the EMG of the EAS and manometry of the IAS. An image including the hyperechoic band that corresponds to the EAS was obtained in all 15 patients. However, the distribution of EAS image was inadequate in high anomalies. In four patients who showed in Kelly score of 5 or 6, good visualization of the EAS was obtained in both anal endosonography and EMG. An Image including the hypoechoic band that corresponds to the IAS was obtained in five patients with high anomalies and in one with intermediate anomalies. Therefore, even in patients with anomalies, at these levels the IAS could be ultrasonically detected. However, only one of these six patients exhibited an anorectal reflex. These results indicate that, for the EAS, the findings of anal endosonography correspond well with those of EMG, but that for the IAS, they do not correspond with those of manometry. At the time of surgery for anorectal anomalies care should taken to preserve the IAS, which can be detected by anal endosonography even in patients with high or intermediate anomalies.

Segmental difference of water and electrolyte transport in rat colon in vivo.

The segmental difference of water and electrolyte transport in the rat colon was studied in vivo. The proximal and distal colon segments were perfused separately but simultaneously at a constant rate with physiological solution, and net movements of water, sodium and chloride were determined. The effects of osmolality and sodium concentration of perfusate were assessed. The effect of a sodium channel blocker on the net transport of water and electrolytes was also studied in each colon segment. The net absorption of water, sodium and chloride correlated with the sodium concentration and osmolality of the perfusion solution in both colon segments and were dominant in the distal colon segment in each condition, compared with that in the proximal colon segment. The concentrations of three electrolytes in the collected fluid were almost the same as those of the perfusion solutions in both segments and these results indicated that water was transported isotonically through the colon lumen. Benzamil, a specific sodium ion channel blocker, inhibited net water and sodium absorption by 58.8% and 63.1% in the proximal colon segment and by 52.0% and 43.6% in the distal colon segment, respectively. These results suggest the existence of an electrogenic sodium transport mechanism and a paracellular pathway in normal (i.e., not treated with corticosteroids or sodium-depleted food) rats which has not been detected in in vitro studies with both apical and basolateral membrane vesicles.

Surgical reconstruction of a high cloacal anomaly with two short vaginas.

We treated a patient with a complex cloacal malformation: a high confluence cloaca and 2 separate short vaginas. At the age of 1 year and 2 months the rectocloacal fistula was closed because of frequent urinary infections, and the vaginas were separated from the wide urogenital sinus and anastomosed to the lower colon. At the age of 2 years and 4 months the lower colon, which had been anastomosed with the 2 vaginas, was pulled down to the perineum to serve as a lower vagina, and the sigmoid colon was pulled through to form a neorectum. She is now 7 years old and goes to school without problems of bowel function or urinary function except that catheterization is done twice a day.

New biofeedback therapy in children with encopresis.

Biofeedback therapy was performed in 13 patients with encopresis using newly devised computerized equipment. The patients were children, aged 6 to 11 years, who had not responded to trials of conventional therapy with a mean follow-up period of three years and two months. The biofeedback therapy was effective in 12 of the 13 patients after one course of therapy. This positive results was attributed to the computerized equipment. The patients could more easily recognize how to squeeze their anal sphincters after seeing a colored ellipse representing sphincter pressure on a monitor. The results of anorectal manometry and electromyography (EMG) showed that biofeedback therapy improved the voluntary sphincter function and rectal sensation. Therefore, biofeedback therapy might be effective in patients with encopresis whose sphincter functions are intact.

Sensation in the anal region and rectum after surgery for anorectal malformations.

Sensation of the anal region and rectum after surgery for anorectal malformations was investigated in 32 patients (17 with high type, 6 with intermediate type and 9 with low type anomaly), aged 5 to 16 years. All patients were examined as to whether or not they could appreciate sensations of touch, pain, heat and cold in the circumanal skin and in the anal canal. Rectal sensation and compliance were also examined by anorectal manometry. All patients had normal sensation in the circumanal skin, but less than half of them had normal sensation in the anal canal. Patients with normal bowel control showed a significantly higher incidence of touch sensation in the anal canal than those with fecal incontinence or constipation. It was suggested that a sensation defect of the anal canal is related to a disturbance of discrimination between flatus and feces. The results of rectal sensation and compliance showed that reduced elasticity of the neorectum and low rectal compliance were important factors of fecal incontinence after surgery for anorectal malformations.

Biofeedback therapy for fecal incontinence after surgery for anorectal malformations: preliminary results.

Eight patients with fecal incontinence after surgery for anorectal malformations received one to four sessions of biofeedback therapy. The physiologic status of the anorectum before and after biofeedback therapy was investigated by anorectal manometry and electromyography of the external sphincter. The effectiveness of biofeedback treatment and the indications for its use in patients with fecal incontinence were investigated. Three of the four patients responded well to biofeedback therapy following three or four training sessions. However, in the other five patients who had only one or two sessions, a good response to the therapy was not obtained. Anorectal manometry and electromyography recordings of the external sphincter showed that biofeedback therapy improved voluntary sphincter function. The three good responders had an adequate and resting pressure both before and after biofeedback therapy and had good electrical activity of the external sphincter after therapy. In the presence of adequate resting and pressure, biofeedback therapy should be attempted for the treatment of fecal incontinence after correction of anorectal malformations before resorting to further surgical intervention. However, biofeedback therapy may not be suitable if the sphincters are markedly hypoplastic, or do not surround the anal canal after an inappropriate pull-through operation.

Thermography in a child with varicocele.

A 12-year-old boy with a left-sided varicocele (Grade 3) was assessed preoperatively and followed postoperatively by computer-assisted infrared thermography. The temperature of the left scrotum was 35.4 degrees C before surgery which was 4 degrees C higher than that of the right scrotum. After ligation of the left internal spermatic vein and removal of the varicocele, scrotal thermograms 39 days and 12 months after operation were normal. Therefore, it seems that thermography is very valuable in the evaluation of testicular function in children with varicocele, in whom semen analysis is impossible.