Transverse vaginal septum associated with tubal atresia.

Transverse vaginal septum is a defect of vertical fusion during embryogenesis of the vagina. The estimated incidence is 1 per 30,000 to 84,000 women. It is infrequently associated with genitourinary tract, gastrointestinal tract, musculoskeletal, and cardiac malformations. Previous reports of transverse vaginal septum have included unilateral absence of the fallopian tube and ovary and absence of the proximal portion of the fallopian tube. This report describes bilateral tubal atresia associated with a transverse vaginal septum. A 17-year-old nulligravida sought medical assessment because of primary amenorrhea and cyclic pelvic pain. Physical examination revealed a blind vaginal pouch and a tender pelvic mass. Radiologic studies showed a transverse vaginal septum 1.5 cm distal to the cervix. The septum was resected with laparoscopic guidance, and bilateral fallopian tubal atresia was noted. The pelvis was otherwise normal. Patients commonly have a pelvic or abdominal mass, pain, and amenorrhea at time of expected menarche. Surgical resection is the treatment of choice. Postoperative dilation may be necessary to prevent restenosis. Outlook for pregnancy is encouraging despite a higher than normal incidence of spontaneous abortion and endometriosis in such patients.

Positive end-expiratory pressure increases the right-to-left shunt in mechanically ventilated patients with patent foramen ovale.

OBJECTIVE: To determine the effect of the presence of a patent foramen ovale on the right-to-left shunt in patients with respiratory failure who receive positive end-expiratory pressure (PEEP). DESIGN: Convenience sample with randomized application of PEEP. SETTING: General intensive care unit of a university teaching hospital. PATIENTS: A total of 46 mechanically ventilated patients with respiratory failure requiring an inspired oxygen concentration of at least 50% and a PEEP of at least 5 cm of H2O. INTERVENTION: Randomized application of PEEP (0 and 10 cm of H2O). MEASUREMENTS: A patent foramen ovale was detected by saline contrast transesophageal echocardiography. The alveolar-to-arterial oxygen difference and the right-to-left shunt were calculated from arterial and venous blood gas sampling. RESULTS: In patients without a patent foramen ovale (n = 39), the alveolar-to-arterial oxygen difference and the shunt fraction decreased (-50 mm Hg [95% CI, -21 to -67] and -0.05 [CI, -0.03 to -0.07], respectively) after adding PEEP (10 cm of H2O). In patients with a patent foramen ovale (n = 7), minimal changes were noted in the alveolar-to-arterial oxygen difference (4 mm Hg, P > 0.2), but the shunt fraction increased (0.05, CI, 0 to 0.09). Adding PEEP (10 cm of H2O) increased the shunt fraction in 6 of 7 (86%) patients with a patent foramen ovale, whereas the shunt increased in only 7 of 39 (18%) patients without a patent foramen ovale (P < 0.007). CONCLUSIONS: A patent foramen ovale was found in 7 of 46 patients (15%; CI, 6% to 29%) with acute respiratory failure. This condition is a common cause of lack of improvement in oxygenation with the addition of PEEP in the mechanically ventilated patient. In patients with a patent foramen ovale, the right-to-left shunt is usually increased by using PEEP.

Impact of transesophageal echocardiogram on the management of acute stroke.

The etiology of cardioembolism is established in only a small percentage of patients. With the recent availability of transesophageal echocardiography (TEE), the detection of a cardiac source has increased, but the usefulness of this added sensitivity is not well established. We recently reported that TEE may show a potential cardiacsource in41% of patients with stroke. This resulted in a change in therapy in only 5% of patients. We now report the reasons for this low impact of the use of TEE in patients with acute stroke. Patients already on anticoagulants, poor risk for anticoagulant therapy, and another more obvious etiology for the stroke were the most common reasons for not changing therapy. Our study suggests that TEE should be reserved for patients with acute stroke in whom an etiology is not evident and in whom detecting a cardiac source would lead to a change in therapy.

Transesophageal echocardiography in the detection of potential cardiac source of embolism in stroke patients.

To compare the diagnostic yields of transesophageal and transthoracic echocardiography in the detection of potential cardiac sources of embolism, 63 patients (mean +/- SD age 63 +/- 15 [range 18-87] years) with transient ischemic attacks or stroke underwent both procedures. Transthoracic echocardiography revealed a potential cardiac source of embolism in 14% (nine) of the patients, all of whom had clinical evidence of heart disease. Transesophageal echocardiography revealed a potential cardiac source of embolism in 41% (26) of the patients; 27% (seven) of these patients had no clinical cardiovascular abnormalities. Abnormalities detected only by transesophageal echocardiography in the patients with unsuspected cardiac disease included atrial septal aneurysm in two, patent foramen ovale in two, left atrial appendage thrombus in one, and myxomatous mitral valve in two. The 26 patients with an identified cardiac source of embolism were older (67.5 versus 59.4 years, p = 0.04), more frequently in atrial fibrillation (62% [16] versus 8% [3], p less than 0.0001), had a larger left atrium (43 versus 37 mm, p = 0.01) and more commonly had left ventricular hypertrophy (62% [16] versus 32% [12], p less than 0.02) than the 37 patients in whom no cardiac source of embolism was identified. Thus, transesophageal echocardiography is more sensitive than transthoracic echocardiography in the detection of potential cardiac sources of embolism in patients with cerebral ischemic events.

Purine concentrations in the cerebrospinal fluid of unanesthetized rats during and after hypoxia.

A new technique for achieving repeated sampling of fourth ventricular cerebrospinal fluid (CSF) from the cisterna magna of unanesthetized rats is described. The sampling cannula is positioned extracranially, in contrast to previously published techniques which require insertion through the skull. CSF samples, withdrawn from unanesthetized rats before, during and after a 25 min period of inhalation of 5% oxygen in nitrogen, were analyzed for their adenosine and inosine contents by high pressure liquid chromatography. Adenosine and inosine levels increased during the hypoxic episode and were even higher 1 h later. They had declined, but were still above basal levels, 2-3 h after the hypoxic episode. Elevated CSF adenosine concentrations may be responsible for the generation of such persistent effects of hypoxia as post-hypoxic respiratory depression.

Respiratory effects of cyclic AMP following injection into the nucleus tractus solitarius of rats.

Rats were anesthetized with urethane and a limited occipital craniotomy was performed to expose the caudal medulla in the region of the obex. Injections were made into sites in the brainstem of spontaneously-breathing rats through glass micropipettes. Tidal volume, respiratory frequency, minute volume, blood pressure and heart rate were recorded before and after the administration of 8-bromoadenosine 3',5'-cyclic monophosphate (Br-cAMP), an analog of cyclic AMP. Injections of Br-cAMP into the ventromedial portion of the caudal nucleus tractus solitarius (NTS) produced dose-related decreases in pulmonary ventilation due to effects on both respiratory frequency, as well as minute volume. In larger doses, Br-cAMP produced periodic apnea and irregular breathing. The respiratory depression was accompanied by transient hypotension and bradycardia. The data indicate that cyclic AMP may function as a second messenger in respiratory control regions in the brainstem.

Cardiovascular effects of microinjection of adenosine into the nucleus tractus solitarius.

Rats were anesthetized with urethane and limited occipital craniotomy was conducted to expose the caudal medulla in the region of the obex. Microinjections of adenosine were made into the nucleus tractus solitarius and heart rate and blood pressure responses recorded. Adenosine produced dose-related decreases in blood pressure and heart rate. The data indicate that adenosine may play a neuromodulatory role in central cardiovascular control areas.

Sensitivity and reversibility of Ca-dependent inhibition of the (Na+ + K+)-ATPase of human red blood cells.

The sensitivity of the (Na+ + K+)-ATPase to inhibition by Ca was increased 30-fold by a partially purified extract of human red cell hemolysate. The hemolysate fraction reduced the concentration of free Ca required for 50% inhibition from 30 microM to approx. 1 microM. Ca-dependent inhibition of the (Na+ + K+)-ATPase in the presence and absence of the hemolysate fraction was completely reversible. The hemolysate fraction also stimulated the Ca2+-ATPase and increased its affinity for Ca. In the presence of the hemolysate fraction, the concentration of free Ca that inhibited the (Na+ + K+)-ATPase by 50% was similar to that which half-maximally stimulated the Ca2+-ATPase. Boiling the fraction destoryed its effect on the (Na+ + K+)-ATPase, but did not impair its stimulation of the Ca2+-ATPase.

The effect of ethanol on the passive Ca permeability of human red cell ghosts measured by means of arsenazo III.

Ethanol in the range of 0.76-2.40 M caused an immediate increase in the Ca permeability of the plasma membrane of resealed human red blood cell ghosts in which intracellular free Ca could be continuously monitored by means of the Ca chromophore arsenazo III. At a given concentration of ethanol, the Ca permeability increased markedly a few minutes following the mixing of the ghosts and the ethanol, and continued to increase over at least the next 30 min. Preincubating the ghosts in ethanol for 15, 60 and 120 min before measuring the rate of free Ca accumulation, progressively increased the effect of a given concentration of ethanol. These results indicate that the effect of a given concentration of ethanol is a complex function of concentration and exposure time. The effects of ethanol in this concentration range were completely reversible. The resealed ghosts used in these experiments were depleted of ATP to avoid interference from the Ca pump and all experiments were carried out with 150 mM KCl on both sides of the membrane to minimize changes in either the volume or membrane potential associated with activation of the Ca-dependent K channel.