Multiple Intrapulmonary Arteriovenous Fistulas in Childhood

Pulmonary arteriovenous fistulas (AVFs) are a rare but recognized cause of cyanosis in childhood. Lesions may be acquired as in hepatopulmonary syndrome or they may be congenital, particularly in association with certain multisystem disorders. Large fistulas are more common than multiple small connections. Two cases, both boys, presenting in the first decade of life are described. ``Bubble' echocardiography was the most telling investigation and strongly suggested the presence of AVFs in both cases. Each patient then underwent cardiac catheterization, which demonstrated normal pulmonary artery pressure and diffuse pulmonary telangiectasis. Both patients were treated effectively with nifedipine and continue with this mode of therapy.     

Management considerations for the pregnant or nursing emergency patient.

It is important to realize the risk-benefit ratio in all therapeutic modalities in any patient and that these variables vary from patient to patient as do circumstances. The emergency patient who is pregnant or nursing should not be feared or be denied appropriate treatment. It is always best to err on the side of safety and remain conservative. The dental problem can usually be treated with the use of adequate local anaesthesia and supplemental nitrous oxide in the second or third trimester. Nevertheless, situations arise that may warrant consultation with the patient's physician or specialist. This brief overview should refamiliarize the dental practitioner with the medications available to treat the gravid patient. It is important to have an understanding of our common therapeutics as well as the inherent treatment risks and benefits as they relate to the changing maternal-fetal physiology.     

NMDA receptor activition by residual glutamate in glutamine preparations: a cautionary note regarding weak NMDA receptor agonists

During an investigation of excitatory amino acids on cultured embryonic Xenopus neurons, we observed that commercial preparations of glutamine had weal agonist activity on NMDA-type glutamate receptors. Threshold responses were observed at 100 μM glutamine, and the dose-response relation did not show inflection or saturation at concentrations of up to 10 mM. However, NMDA receptor activation induced by glutamine probably represented activity of residual glutamate because: (a) recrystallization of glutamine reduced residual glutamate levels (measured by HPLC analysis) and NMDA receptor activation by comparable amounts; and (b) glutamate at concentrations close to those predicted to be present in glutamine preparations elicited currents of similar amplitudes. Our data indicate that residual glutamate at levels of less than 0.05% are sufficient to confound studies of weak NMDA receptor agonists.     

The use of Forane anesthesia for surface-induced deep hypothermia.

The effects of Forane anesthesia for deep surface hypothermia with 30 minutes of total circulatory occlusion were evaluated. With 100% O2 6 of 7 dogs developed motor disorders postoperatively, while 3 of 5 with 98% O2/2% CO2 and none with 95% O2/5% CO2 developed motor disorders. Cooling was uneventful except for 1 episode of ventricular fibrillation in the 5% CO2 group at 23 degrees C. Resuscitation was easy, but the early rewarming period was characterized by repeated episodes of ventricular fibrillation and delayed recovery of cardiac function, especially in the 100% O2 group. Blood lactate levels remained low during cooling and gradually increased during rewarming in all groups, with the highest levels in the 100% O2 group and the lowest in the 5% CO2 group. It is concluded that Forane can be used for surface hypothermia with 30 minutes' circulatory occlusion when administered in 95% O2/5% CO2. A Comparison of these results with previously reported series indicates that Forane is inferior to ether but may be superior to halothane for surface hypothermia.     

A comparison of the effects of cytosine arabinoside and adenine arabinoside on some aspects of brain growth and development in the rat.

1. Treatment of pregnant rats with cytosine arabinoside (ara-C, 50 mg/kg, i.p.)at 14 days of gestation severely impaired both prenatal and postnatal whole brain growth in their offspring, although the cerebellum was relatively less affected than whole brain. 2. Rats treated at 5 days of age with ara-C (250 mg/kg, i.p.) showed an impairment in growth of the cerebellum relative to the rest of the brain. 3. Adenine arabinoside (ara-A) treatment, either prenatally or postnatally, had negligible effect on brain growth, even at doses considerably higher than those of ara-C. 4. Adult rats, previously treated with ara-C (50 mg/kg, i.p.) at 14 days of gestation, showed an impairment in discrimination learning when tested in a water T-maze. 5. These results are discussed in relation to the proposed use of ara-C or ara-A as antiviral agents, particularly against intrauterine infection with cytomegalovirus.     

Treatment of anorectal gonorrhea infections in men

The charts of 606 men with anorectal gonorrhea infections treated using the current Public Health Service recommendations were reviewed. There were 3.3% failures in the group treated with penicillin--14.4% in those treated with tetracycline hydrochloride, 14.8% in the ampicillin trihydrate group, and none among those treated with spectinomycin hydrochloride. The intramuscular (IM) injection of penicillin G procaine, 4.8 million units, with 1 g of probenicid given orally is the treatment of choice for anorectal gonorrhea. An IM injection of 2 g of spectinomycin hydrochloride was effective but should be reserved for patients allergic to penicillin and for penicillin treatment failures.