Effects of imipramine on responding reduced by methadone

Interactions between methadone and acute and chronic imipramine were studied in pigeons key pecking under a multiple variable interval 15-sec variable interval 150-sec schedule of food presentation. Both drugs decreased response rates at the highest doses. The VI 15-sec schedule was slightly more sensitive to acute drug administration than was the variable interval 150-sec schedule. Acute combinations of the two drugs neither ameliorated nor exacerbated the effects of either drug alone. Chronic imipramine alone had no lasting effect on responding. Unlike acute combinations, chronic imipramine lessened the rate reducing effect of methadone.

Structural similarity between the lepidoptera- and diptera-specific insecticidal endotoxin genes of Bacillus thuringiensis subsp. "kurstaki" and "israelensis"

A gene from Bacillus thuringiensis subsp. "israelensis" was cloned from the large plasmids of this subspecies and was shown to code for a mosquitocidal polypeptide. The gene could be expressed in either Escherichia coli, Bacillus subtilis, or B. thuringiensis subsp. "israelensis" to produce the larvicidal activity. Similarly, a Lepidoptera-specific toxin gene from B. thuringiensis subsp. "kurstaki" was also cloned and expressed in E. coli and B. subtilis. Both cloned genes were sequenced and subjected to computer analysis. A long open translational reading frame coded for the B. thuringiensis subsp. "kurstaki" gene product. However, the B. thuringiensis subsp. "israelensis" clone was composed of two adjacent open reading frames oriented as if they were in a transcriptional operon. The products of the cloned genes retained their specificity for either Lepidoptera or Diptera. The control regions immediately preceding the toxin genes of both B. thuringiensis subspecies showed considerable DNA homology, most likely because both toxins are expressed only during sporulation. In addition, the deduced amino acid sequences from the two contiguous B. thuringiensis subsp. "israelensis" genes bore a striking resemblance to the deduced amino acid sequence from the single larger B. thuringiensis subsp. "kurstaki" gene, as if these two arrangements were evolutionarily related.

Suppression of secondary hyperparathyroidism in children with chronic renal failure by high dose phosphate binders: calcium carbonate versus aluminium hydroxide

Secondary hyperparathyroidism was suppressed over a period of one year in 12 children with chronic renal failure by using a regimen of mild dietary phosphate restriction and high dose phosphate binders. The patients were randomised to receive either aluminium hydroxide or calcium carbonate by mouth for six months and then crossed over to the other medication. Vitamin D (dihydrotachysterol) dosage was unchanged. Serum parathyroid hormone concentrations were reduced to within the normal range, urinary cyclic adenosine monophosphate values fell, plasma phosphate concentrations decreased, and the theoretical renal phosphate threshold increased significantly. Transiliac bone biopsy findings improved in four patients with adequate suppression of parathyroid hormone concentrations, deteriorated in two patients who were not compliant, and did not change in five patients in whom initial bone disease was mild. Growth velocity improved significantly. There was no difference in the clinical response, biochemical changes, or incidence of complications during treatment with the two agents. In view of the risk of aluminium toxicity the use of high dose calcium carbonate with dietary phosphate restriction and vitamin D supplementation is recommended in the control of secondary hyperparathyroidism in children with chronic renal failure.

Ureteral involvement complicating eosinophilic cystitis

A thirty-three-year-old woman was evaluated for eosinophilia, irritative bladder symptoms, and renal insufficiency. Eosinophilic cystitis was documented by bladder biopsy and glomerulonephritis by renal biopsy. As the glomerulonephritis and other symptoms resolved, unilateral ureteral obstruction developed with irreversible loss of right renal function. The distal ureter was found to have eosinophilic infiltration. This entity should be considered in the differential diagnosis of unilateral ureteral obstruction associated with cystitis.

Tc-99m glucoheptonate scintigraphy in a case of renal vein thrombosis

Tc-99m glucoheptonate flow and static studies with computer-assisted analysis provided specific diagnostic information in unilateral renal vein thrombosis complicating a case of nephrotic syndrome. Decreased flow with congestion, a large kidney with parenchymal thickening, pelvocalyceal thinning, good function, and no obstruction in the proper clinical settings indicated the diagnosis of a chronic form of renal vein thrombosis with compensating collateralization. The differential diagnosis is discussed.

Dining arrangements and behavior of severely mentally retarded adults

The behavior of 12 severely and profoundly mentally retarded men and women living in a 64-bed community residence was studied during large group (congregate) and small group dining arrangements. Four adaptive and four maladaptive mealtime behaviors were recorded using a coded partial interval time sampling procedure, employing a with-subject reversal design. Adaptive dining behaviors increased (15.9% to 93.6%) and maladaptive behaviors associated with meals decreased (28.8% to 8.5%) during small group dining periods. The relation of client behavior to variables in addition to group size is discussed.

Behavioral pharmacokinetics of marijuana

Male volunteer subjects smoked one marijuana cigarette containing 100, 200, or 250 micrograms/kg delta-9-tetrahydrocannabinol (THC) and were tested on three perceptual-motor performance measures related to driving. Performance was measured and blood samples were collected for 24 h after smoking. The covariation between pharmacodynamics of performance and pharmacokinetics of THC in plasma was investigated for decrement in performance as the response to smoking a single marijuana cigarette. A significant linear correlation was found between tracking errors under divided attention and THC plasma levels over 5-25 ng/ml for approximately 2 h after smoking. A sigmoid relation was found between critical tracking breakpoint and log THC plasma levels over 2-25 ng/ml for approximately 7 h after smoking.

The effects of methadone on operant behavior maintained with and without conditioned reinforcement in the pigeon

Effects of methadone on key pecking supplemented with brief stimuli either correlated with or independent of unconditioned reinforcement was investigated. On average, key pecks by pigeons produced brief stimuli (BS) once per minute and food once per 4 min during both components of a multiple schedule (i.e., VI1 : BS, VI4 : Food). Brief stimuli were paired with food presentation during one component and not related to food during the second component. Acute methadone administration (0.56, 1.0, 1.7, and 3.0 mg/kg) decreased response rates during both components; however, the decrease was smaller by a constant amount during the paired brief stimulus component, regardless of drug dose. These results suggest conditioned reinforcement is not a primary mechanism through which methadone exerts behavioral effects and that reinforcer-correlated stimuli have potential for diminishing the reduced behavioral output observed following methadone administration.

Interval and ratio reinforcement contingencies as determinants of methadone's effects

The effects of methadone hydrochloride on lever pressing rats maintained under multiple fixed-interval and fixed-ratio, or multiple variable-interval and variable-ratio reinforcement schedules equated for reinforcement density were examined. Under a multiple fixed-interval, fixed-ratio schedule overall response rate was decreased during both components but was most affected under the ratio schedule. Response rate decreases were due primarily to changes in running rate rather than pause time. Under a multiple variable-interval, variable-ratio schedule, overall response rate was also decreased by methadone, with the greatest decrease again occurring during the ratio schedule. These schedule-specific methadone effects are not due to differences in reinforcement frequency. Evidence for rate-dependency with methadone is not consistent across subjects.

Management of intracardiac fungal masses in premature infants

Intracardiac fungal masses can develop following episodes of candidemia in premature infants with indwelling right atrial lines. We report the first premortem diagnosis and successful surgical removal of Candida-containing intracardiac masses in three premature infants. All had central venous lines and had been on systemic antibiotics prior to the development of candidemia. By echocardiography, two were pedunculated, solitary masses within the right atrium. Amphotericin B and 5-flucytosine for 21 to 42 days controlled the Candida sepsis, but the masses became increasingly mobile and did not decrease in size. In the third infant, large, irregular masses extended from the right atrium to the main pulmonary artery, and surgical removal was recommended 4 days after the start of antifungal therapy. In all three patients, the masses were nearly the size of the main pulmonary artery and presumably contained viable organisms. Removal was accomplished with the aid of cardiopulmonary bypass for two and inflow stasis for one infant weighing only 1,300 gm. The masses were filled with viable Candida organisms. All patients tolerated the operation well and have been followed up for 1 to 3.6 years without evidence of recurrent Candida infection. The case of a fourth infant, weighing 1,320 gm, is also reported. This infant had a bacteria-containing intra-atrial mass, which was removed successfully with the aid of inflow occlusion. This report documents the following points: (1) Echocardiography provides a noninvasive method of diagnosing the development of intracardiac masses and should be performed in infants who have had candidemia and a central venous line. (2) Prolonged systemic antifungal therapy does not appear to either sterilize or promote regression of the masses. (3) The masses can be safely removed, even in the premature infant, with either inflow stasis or cardiopulmonary bypass. (4) Surgical removal is an effective component of the treatment of infection in these infants.

Studies of rhenium carboxylates as antitumor agents. Part II. Antitumor studies of bis (mu-propionato) diaquotetrabromodirhenium (III) in tumor-bearing mice

The neutral, dimeric complexes of rhenium, bis (mu-carboxalato)-diaquotetrahalodirhenium (III) (carboxalato = acetato, propionato, or butyrato and halo = chloro or bromo), were synthesized and survival studies were done on mice bearing P-388 leukemia or B-16 melanoma. The complex bis (mu-propionato) diaquotetrabromodirhenium (III) proved to be the most effective in increasing the life span of the mice. The complex showed some activity against B-16, but virtually none against P-388. The complexes are all quite non-toxic.

Perinatal stress: a study of factors linked to the risk of parenting problems

Infants who are born preterm are at high risk for subsequent maltreatment. This study examines the relationship between family functioning, infant morbidity, parents' experience following their infant's admission to a neonatal intensive care unit, and postdischarge risk of parenting problems. For the sample as a whole, family factors emerged as the best predictors of outcome.

Measurement of the fasting urinary hydroxyproline: creatinine ratio in normal adults and its variation with age and sex

Conditions for the determination of the fasting urinary hydroxyproline: creatinine ratio (OHPr: Cr ratio) have been examined, using a resin-catalysed hydrolysis and automated colorimetric procedure for the determination of hydroxyproline. Feeding experiments with gelatin showed that hydroxyproline is rapidly absorbed and excreted in the urine and that a 12-hour (overnight) fast is sufficient to ensure correct and reproducible fasting OHPr: Cr ratios. The mean fasting OHPr: Cr ratio decreased slightly with increasing age in both men and premenopausal women but there was no significant difference between the sexes. There was, however, a significant increase in the mean ratio in postmenopausal women. The normal range of fasting OHPr: Cr ratios for men and premenopausal women was found to be 0.003--0.015.

Perinatal factors and the developmental outcome of preterm infants

To determine the developmental outcome of sick preterm infants, a retrospective analysis of 101 preterm infant survivors, cared for a teaching hospital's neonatal intensive care unit, was conducted. Information regarding the one-year developmental outcome was compared with significant perinatal factors: birth weight, gestational age, neonatal mortality index, respiratory distress syndrome (RDS) severity, and high-risk pregnancy factors. Eighteen percent of all infants studied had developmental delays indicating an improved prognosis for preterm infants. Severe RDS survivors had the greatest incidence of developmental delays and the most high-risk pregnancy histories.

Immune thrombocytopenia in severe neonatal infections

Thrombocytopenia occurs frequently in newborn infants with sepsis, but the exact mechanism remains obscure in those infants who do not have evidence of disseminated intravascular coagulation. Since recent work has suggested a possible immune mechanism for thrombocytopenia observed in adults with sepsis, we have investigated the role of platelet-associated immunoglobulin in severe neonatal infections. To detect PAIgG we use a method employing protein A and peroxidase-antiperoxidase as a labeled antibody. PAIgG was quantitated by phase contrast microscopy and expressed as a reactive index. Our control group included 16 normal newborn infants whose mean RI was 0.65 +/- 0.01 SE. In addition to the control group, five infants with nonimmune thrombocytopenia were included; their mean RI was 0.66 +/- 0.01 SE. Seventeen newborn infants with severe infections were assayed for PAIgG. Eight of nine infants with bacterial infections had increased RI, with a mean of 1.16 +/- 0.03 SE (P less than 0.01). Six of the eight infants with viral infections had elevated RI, with a mean of 1.23 +/- 0.03 SE (P less than 0.01). These findings suggest that an immune mechanism may be involved in the thrombocytopenia of severe neonatal infection.

Peptic ulcer disease in early infancy: clinical presentation and roentgenographic features

Sixteen infants under 11 weeks of age developed documented peptic ulcer disease involving the stomach, duodenum or pylorus during an eight-year period in a Newborn Intensive Care Unit. The precipitous onset of gastrointestinal bleeding and/or perforation commonly associated with ulcer disease in early infancy was present in only seven (44%) of the 16 patients. The remaining nine infants (56%) presented with recurrent emesis, a presentation of peptic ulcer disease rarely described in the first weeks of life. Contrast radiography was used to demonstrate a definite ulcer crate in 13 of these patients. Two had their ulcers diagnosed at surgery and one by endoscopy. Radiographic demonstration of pylorospasm and/or gastric retention was often associated with ulcer craters located in the pyloric channel or gastric antrum. Only two patients required surgery for massive bleeding and perforation. The remainder were successfully managed medically using orogastric suction antacids and gradual resumption of milk feedings. There were no deaths within our population attributable to peptic ulcer disease.