Phenobarbital improves survival in theophylline-intoxicated rabbits

As in humans, theophylline intoxication in rabbits causes seizures and death. We studied whether the administration of phenobarbital or phenytoin following a toxic dose of theophylline would improve survival in rabbits. New Zealand white rabbits were infused intravenously with theophylline, 115 mg/kg over 50 minutes. Upon completion of the infusion, rabbits were randomized to receive either saline (control) (N = 60) or saline containing phenobarbital 20 mg/kg (N = 60), or phenytoin 12 mg/kg (N = 30), infused over 30 minutes. The number (and percentage) of rabbits surviving 24 hours in each group was: control 12 (20%), phenobarbital 30 (50%), and phenytoin 7 (23%) [X2; p less than 0.005; two-tailed]. In all fatal cases, death was preceded by a seizure; rabbits that survived did not seize. These results show that phenobarbital administered intravenously to theophylline-intoxicated rabbits prevented seizures and improved survival whereas phenytoin administration had no significant effect.     

Acute toxicity of a nuclear magnetic resonance cerebral blood flow indicator in cats

We studied trifluoromethane as a potential gaseous indicator in nuclear magnetic resonance measurements of cerebral blood flow. We considered the effects of trifluoromethane on cerebral blood flow in 17 cats and on the electroencephalogram and electrocardiogram in nine cats and compared these with the effects of the more toxic compound chlorodifluoromethane in five cats. Inhaled at 60%, trifluoromethane had no effect on cerebral blood flow, the cerebral metabolic rate for oxygen, or oxyhemoglobin content. At 70%, trifluoromethane sensitized the cats' hearts to epinephrine, but to a much lesser degree than 40% chlorodifluoromethane, and produced only moderate changes in cerebral electrical activity as measured by the electroencephalogram. We found trifluoromethane to be suitable for use in animals, but its toxicity needs to be studied further before it can be used in humans for the measurement of cerebral blood flow.     

The spectrum of sonographic findings in hemorrhagic ovarian cysts

The sonograms of 76 hemorrhagic ovarian cysts were reviewed to ascertain the full spectrum of sonographic findings. All cases were proved either by surgery or by documented resolution on sonography and/or clinical follow-up. The overwhelming majority (92%) had increased sound through-transmission, signifying the basic cystic nature of the lesion. The sonographic patterns were variable. The most common appearance was that of a heterogeneous mass (83%), almost half of which were predominantly anechoic with hypoechoic material. The other cases (17%) were completely homogeneous, either hypo- or hyperechoic. No masses were completely anechoic. Additional sonographic features included a thick rim, septations, and associated cul-de-sac fluid. A rounded hyperechoic mass, representing blood clot, was contained within 13 masses. In addition, some women appeared to have an increased tendency to form ovarian cysts, suggested by the fact that 26% of them had a past, concurrent, or future episode of simple or hemorrhagic ovarian cysts. Because hemorrhagic ovarian cysts have variable sonographic findings, they should be included in the differential diagnosis of any adnexal mass that has good sound through-transmission.     

Histopathologic study of autosomal dominant vitreoretinochoroidopathy. Peripheral annular pigmentary dystrophy of the retina

Autosomal dominant vitreoretinochoroidopathy (ADVIRC), a recently described disease, is clinically characterized by a slowly progressive or stationary circumferential peripheral pigmentary retinopathy with fibrillar condensation of the vitreous. Histopathologic study of an 88-year-old patient with this disease showed disorganization of the peripheral retina with focally atrophic retinal pigment epithelium (RPE). Altered pigment epithelial cells surrounded retinal blood vessels and lined the internal limiting membrane. At the equator, a remarkable and possibly unique multifocal loss of photoreceptor cells was seen. An extensive preretinal membrane, consisting of condensed vitreous with cellular debris and layers of Müller cells, was demonstrated by electron microscopic examination and immunohistochemistry. Histologically, this entity has some similarities to and some differences from retinitis pigmentosa. The clinical features are distinctive.     

Outcome of schizoaffective disorder at two long-term follow-ups: comparisons with outcome of schizophrenia and affective disorders

OBJECTIVE: This research assessed whether the outcome of schizoaffective disorder is more similar to that of schizophrenia or that of affective disorders. METHOD: The authors conducted a prospective follow-up study of 101 schizoaffective, schizophrenic, bipolar manic, and depressed patients assessed at three times: during hospitalization and 2 and 4-5 years later. The follow-up test battery involved detailed assessment of social functioning, work performance, symptoms, posthospital treatment, and rehospitalization. RESULTS: Outcome for schizoaffective patients 4-5 years after hospitalization differed significantly from that for patients with unipolar depression. However, the differences between schizoaffective and bipolar manic patients were more equivocal. Unlike the patients with bipolar disorder, only a limited number of patients with schizoaffective disorder showed complete recovery in all areas throughout the year preceding the 2-year follow-up and the year preceding the 4- to 5-year follow-up. The differences in outcome between schizoaffective and schizophrenic patients were also mixed. These two groups showed some similarities in outcome, but there were fewer schizoaffective than schizophrenic patients with uniformly poor outcome in all areas. CONCLUSIONS: Overall, schizoaffective patients showed some similarities to both schizophrenic and bipolar manic patients. Schizoaffective patients had somewhat better overall posthospital functioning than patients with schizophrenia, somewhat poorer functioning than bipolar manic patients, and significantly poorer functioning than patients with unipolar depression. The data suggest that when mood-incongruent, schizophrenic-like psychotic symptoms are present in the acute phase, they predict considerable difficulty in outcome, even when affective syndromes are also present, as in schizoaffective disorder. It is likely that schizoaffective disorder is not just a simple variety of affective disorder.     

A pharmacogenetic evaluation of the role of local anesthetic actions in the cocaine kindling process.

Repeated administration of subconvulsant doses of lidocaine or cocaine results in the development of an increased susceptibility to seizures induced by the two drugs (pharmacological kindling). It has been hypothesized that the local anesthetic properties of cocaine are responsible for its convulsant and epileptogenic actions. As genetic factors appear to mediate acute sensitivity to the convulsant properties of cocaine and the development of cocaine-kindled seizures, the present studies used a pharmacogenetic approach to address this question further. The convulsant effects of lidocaine were evaluated in BALB, C57, DBA and SJL mice and compared with previous studies evaluating cocaine-induced seizures. We have also evaluated the development of lidocaine- versus cocaine-kindled seizures and the effects of repeated treatment with cocaine or lidocaine on subsequent lidocaine seizure susceptibility in three of these inbred mouse strains. As observed for cocaine, genetic factors influence the convulsant properties of lidocaine; however, the differences between the strains of mice in susceptibility to lidocaine-induced seizures (SJL greater than DBA = BALB = C57) did not parallel those seen for cocaine-induced seizures (C57 greater than DBA = BALB greater than SJL). Similarly, the time course for the expression of kindled seizures and the differences between the various inbred strains were not the same for lidocaine kindling and cocaine kindling. However, depending on the genetic background of the subject, the repeated administration of lidocaine, or cocaine, resulted in the development of sensitization or tolerance to the convulsant effects of lidocaine in an identical manner.(ABSTRACT TRUNCATED AT 250 WORDS)