Aneurysms complicating pulmonary autograft procedure for aortic valve replacement

Aneurysm formation in the left ventricular outflow tract related to the proximal end of the pulmonary autograft after the Ross procedure was present in 2 patients. Both occurred late after operation and were associated with prolapse of a leaflet of the autograft and significant regurgitation. Both were repaired with no immediate complications. There was no evidence of infection at time of operation. The probable mechanisms underlying this complication and the possibilities of avoiding it are discussed.     

Additive effect of indomethacin and methotrexate on suppression of growth in rats

The purpose of this study was to investigate the medium-term effects of methotrexate (MTX) and indomethacin on the growth of young rats. Four equal groups of Sprague-Dawley male rats (four animals in each group; mean+/-S.D. body weight, 183+/-13 g, in their rapid growth phase) were subjected to the following drug treatment: one group was given MTX (0.2 mg kg(-1) body weight) subcutaneously on every fourth day, another received indomethacin (2.5 mg kg(-1) body weight) subcutaneously daily and the third group was given both of these drugs (MTX on every fourth day and indomethacin daily). The fourth group was injected subcutaneously with physiological saline every day to serve as a control group. Total body weight, food and water consumption by animals in each group were monitored every second day for a period of 10 weeks. After this period, liver, spleen and kidneys were excised, weighed and analysed for MTX and dihydrofolate reductase activity. Compared with the groups, which received MTX alone, indomethacin alone, or physiological saline, mean increase (17+/-11 g) in body weight of rats was minimal in the group receiving both MTX and indomethacin. The difference was statistically significant (p=0.001) when the values of mean increase in body weight of rats in different treatment groups after a 10-week treatment were compared. The mean weights of liver and spleen in this group receiving both MTX and indomethacin were also found to be significantly less than the weights of these organs in the control group (p<0.01). There also appears to be a decline in food consumption in this group (p<0.05). This negative effect on growth of animals in this group appears to be not only due to decreased food consumption but also due to increased inhibition of de novo pathway of DNA synthesis. This is supported by increased accumulation of MTX and decreased dihydrofolate reductase activity in this group receiving both MTX and indomethacin, as compared with the group receiving MTX alone. The data indicate an additive effect of MTX and indomethacin on the suppression of growth in young rats, alluding to the notion that patients suffering from juvenile rheumatoid arthritis or acute lymphoblastic leukaemia receiving these two drugs concomitantly over a long period of time might be at a risk of experiencing short-term suppression of growth.     

Breast feeding may protect children against Campylobacter jejuni associated diarrhoea

To investigate the bacterial etiology of infant diarrhea in Karachi, Pakistan, 180 rectal swab samples collected from diarrhea patients under 5 years of age and 30 samples from age- and sex-matched healthy children were analyzed. Enteropathogenic organisms were isolated from 70 case samples (38.9%). The two most common etiologic agents were Campylobacter jejuni (19.4%) and Aeromonas hydrophilia (6.1%). Salmonella, Shigella, and Yersina appear to have a limited incidence in this age group. None of the control specimens yielded any enteropathogen. Breast-fed infants had a significantly lower risk of enteric infection. A pathogen was isolated in 26.0% of samples from breast-fed children with diarrhea compared with 46.8% of samples from bottle-fed diarrhea patients. All C jejuni infections identified in this study involved bottle-fed children. Boiled water was used to prepare infant formula in only 31.1% of these patients. These findings are consistent with those of other studies showing a decreased rate or severity of diarrhea in breast-fed infants. Mothers should be encouraged to breast feed their infants or, if this is not possible, to use boiled water for the preparation of infant formula.     

Effect of tetrakis-μ-3,5-diisopropylsalicylatodiaquodicopper(II) on the status of reduced glutathione in freshly isolated hepatocytes

Effects of different concentrations of tetrakis--3,5-diisopropylsalicylatodiaquodicopper(II) (Cu(II)₂(3,5-DIPS)₄(H₂O)₂) on the reduced status of glutathione (GSH), the major nonprotein thiol in tissues, were investigated using freshly isolated hepatocytes. Cu(II)₂(3,5-DIPS)₄ below 100 M did not have any significant effects on either the GSH content or viability of the hepatocytes, but at 150–250 M it decreased both parameters after 1 h of incubation. The decrease in cellular GSH was not followed by an increase in the oxidized form of GSH (GSSG) in the cell suspension. The addition of deferoxamine with Cu(II)₂(3,5-DIPS)₄ to the hepatocyte suspension prevented depletion in GSH content and loss of cell viability by Cu(II)₂(3,5-DIPS)₄. Both GSH depletion and loss of cell viability were found to be Cu(II)₂(3,5-DIPS)₄ dose dependent. From these results, it appears that Cu(II)₂(3,5-DIPS)₄ penetrated the cell membrane and acted by decreasing the GSH level by forming a copper-glutathione complex.     

Relative pharmacokinetics of three amikacin brands in onco-hemotologic pediatric patients experiencing febrile neutropeina.

Three commercially available brands of amikacin were investigated in a parallel study design for the assessment of comparative pharmacokinetics in pediatric oncology patients with chemotherapy-induced neutropenic febrile episode. Amikacin concentration in serum samples was determined by fluorescence polarization immunoassay method using Abbott TDx system. Computer software, PK II was used for computation of pharmacokinetic parameters of amikacin. The serum concentration of all brands nonsignificantly (p > 0.05) varied at all time points, except at 1 and 2 hrs post dosing. At 1 hr post dosing, the serum concentration of brand II varied from rest of two brands. Whereas at 2 hr following I/V infusion, brands II and I were statistically different. Highest serum concentration of 38.69 +/- 1.45 microg/ml was observed in case of brand III while brands I and II showed lower but not significantly different serum concentration values, i.e., 36.30 +/- 1.65 and 37.89 +/- 1.32 microg/ml, respectively when compared with brand I. The other pharmacokinetic parameters of 3 brands found to have non-significant difference (P < 0.05) except, t(1/2)alpha and Cl of brands I and II that deviated statistically significant (p < 0.01). The relative bioavailability of brand II and III as compared with brand I, considered as standard 86.17 and 96.86%, respectively falls within the accepted limits of +/- 20% required for the bioequivalence of any two brands. Based upon findings of the present study, all these brands may be used interchangeably in oncology patients. Further studies, however are needed to determine whether the statistically elevated Cl value in brand II is of any clinical significance.     

Supraventricular arrhythmia: A complication of 5-fluorouracil therapy

5-Fluorouracil is an S-phase-specific, synthetic pyrimidine antimetabolite, which is used as a cytostatic agent for a variety of malignant lesions, either singly or in multidrug regimens. Gastrointestinal toxicity and myelosuppression are the most common adverse reactions, but, of late, clinical cardiotoxicity has been reported in both prospective and retrospective studies. We present our experience of clinical cardiotoxicity in five patients.     

Vestibular schwannoma growth rates in neurofibromatosis type 2 natural history consortium subjects.

OBJECTIVE: To determine the amount of growth in vestibular schwannomas in Neurofibromatosis type 2 (NF2) patients from diagnosis through short-term (up to 2 yr) and long-term (up to 4 yr) follow-up. STUDY DESIGN: Retrospective magnetic resonance imaging (MRI) films were obtained on subjects enrolled in the NF2 Natural History study and examined for changes in vestibular schwannoma size over time. SETTING: Data were collected from nine foreign and domestic NF2 centers, including hospital-based, academic, and tertiary care centers. SUBJECTS: NF2 patients with MRI data and at least one follow-up examination within 9 months to 2 years of diagnosis were included; n=56 patients with 84 lesions for evaluation of growth. INTERVENTION: Routine, clinically obtained, magnetic resonance images were digitized and measured using image management software. Short-term follow-up was defined as up to 2 years (n=84 lesions), and long-term follow-up was defined as 3 to 4 years (n=29 lesions). OUTCOME MEASURES: Vestibular schwannoma size was assessed using anterior-posterior, medial-lateral, and greatest diameter linear measurements. RESULTS: Vestibular schwannomas increased in size (at least 5 mm) in 8% of the vestibular schwannomas across short-term follow-up. At long-term follow-up, 13% of the tumors had increased in size. On average, schwannomas increased in greatest diameter 1.3 mm per year across short-term follow-up. CONCLUSION: Slightly greater than 1 in 10 diagnosed NF2-related vestibular schwannomas increased in size by at least 5 mm by 4 years of follow-up, if still untreated at that time.     

Interspeaker variation in habitual speaking rate: additional evidence.

PURPOSE: The purpose of the present study was to test the hypothesis that talkers previously classified by Y.-C. Tsao and G. Weismer (1997) as habitually fast versus habitually slow would show differences in the way they manipulated articulation rate across the rate continuum. METHOD: Thirty talkers previously classified by Tsao and Weismer (1997) as having habitually slow (n = 15; 7 males, 8 females) and habitually fast (n = 15; 8 males, 7 females) articulation rates produced a single sentence at 7 different rates, using a magnitude production paradigm. Hence, the participants were not randomly assigned to conditions. RESULTS: Quadratic regression functions relating measured to intended articulation rates were all statistically significant, and most important, there were significant differences between the slow and fast groups in the y intercepts of the functions, for both males and females. CONCLUSIONS: This study provides a constructive replication of Tsao and Weismer (1997), showing a difference between slow and fast talkers with a new set of speech materials and in a new task. The findings appear to be consistent with a biological basis for intertalker rate differences.