Variability of plasma phenobarbitone concentration in Asian children in Singapore

In a study with 113 Asian children in which phenobarbitone was used as the sole antiepileptic drug in 75 children, including Chinese, Malays, and Indians, the mean phenobarbitone dosage required to produce a plasma level of 15 micrograms/ml was 5.2 mg/kg/day. While the mean plasma level/dose ratio varied, the differences between the three ethnic groups were not statistically significant. Also of little difference were the ratios between the male and female groups. For those patients with poor seizure control, however, the mean plasma level/dose ratio was significantly lower than in those whose seizures were controlled. Using additional anticonvulsant drugs concurrently with phenobarbitone in 40 children raised the mean plasma level/dose ratios significantly in each ethnic group. Further, the greater age level in those given additional antiepileptic drugs might have contributed slightly to a higher mean plasma level/dose ratio.

Non-dinitrophenyl-binding immunoglobulin that bears a dominant idiotype (Id460) associated with antidinitrophenyl antibody is specific for an antigen on Pasteurella pneumotropica

We have previously described an idiotype (Id460) that transiently dominates anti-2,4-dinitrophenyl (DNP) antibody responses of mice that possess the appropriate Igh-V and V kappa genotypes. Normal serum has significant levels of Id460 that does not bind DNP, and hybridomas derived from spleen cell fusions that produce monoclonal antibodies with these characteristics have been generated. Many of these monoclonal, Id460-positive antibodies bind the opportunistic mouse pathogen Pasteurella pneumotropica. P. pneumotropica induces a marked increase in serum Id460 titers without significantly increasing serum anti-DNP titers. Both normal serum and P. pneumotropica-induced Ig460-positive immunoglobulin specifically bind to P. pneumotropica. These results suggest that the normal serum Id460-positive immunoglobulin is induced by environmentally encountered antigens on P. pneumotropica. We propose that this naturally occurring Id460 activates antiidiotypic regulatory cells that in turn promote production of Id460-positive anti-DNP antibody following DNP-ovalbumin immunization. These data are compatible with those obtained in several other idiotypic systems that suggest that dominant idiotypes may be associated with antibodies that have been evolutionarily selected for expression because of their specificity for antigens on environmentally encountered pathogens.

Phosphoinositide breakdown in blowfly salivary glands

In blowfly salivary glands, 5-hydroxytryptamine stimulated a rapid and sustained loss of [3H]inositol, [32P]phosphatidylinositol, phosphatidylinositol 4-phosphate, and phosphatidylinositol 4,5-bisphosphate. There was a corresponding increase in labeled inositol phosphates. In the absence of Ca2+, 5-hydroxytryptamine stimulated a rapid but transient loss of labeled phosphatidylinositol 4,5-bisphosphate. By 5 min, the amount of labeled phosphatidylinositol 4,5-bisphosphate recovered to control values. The divalent ionophore A23187 stimulated loss of labeled phosphatidylinositol 4,5-bisphosphate and increased the amount of labeled phosphatidylinositol. In homogenates, Ca2+ stimulated phosphatidylinositol 4,5-bisphosphate breakdown but not phosphatidylinositol breakdown. These results suggest that hormone-stimulated breakdown of labeled phosphatidylinositol and phosphatidylinositol 4,5-bisphosphate occurs through a phospholipase C and is relatively independent of extracellular Ca2+. There is also a Ca2+-activated conversion of phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol.

Proper aerosol inhalation technique for delivery of asthma medications

Forty-two (42) children with asthma, 7 to 15 years old, who had been taking aerosol medications from canister nebulizers for longer than 6 months were evaluated for adequacy of aerosol inhalation technique. The mouthpiece of a canister nebulizer was modified so that actuation of the canister and inhalation through the mouthpiece could be recorded. Of 42 patients, 24 had correct inhalation technique (they synchronized the actuation of canister and inhalation); 18 (43%) did not. The most frequent mistake (11 patients) was releasing the aerosol into the mouth without inhaling. Those who inhaled incorrectly were taught the correct technique by repeated instructions and demonstrations; 11 learned it within 5 minutes, but 7 required a longer instruction period. Most had retained the technique when retested later. The physician should teach each patient the correct technique when aerosol therapy is started and should check again on follow-up examinations to assure that the patient obtains maximum benefit from aerosol therapy.

Total skin electron beam therapy for cutaneous lymphomas and leukemias

Total skin electron beam therapy (TSEB) was used in the treatment of 33 patients with lymphoma and 13 patients with leukemia involving extensive segments of the skin surface. Twenty-two of 23 had skin lesions as a primary manifestation of lymphoma (primary cutaneous lymphoma--PCL) and 11 developed cutaneous lesions following disseminated nodal lymphoma (secondary cutaneous lymphoma--SCL). A once weekly fractionation scheme was employed to irradiate the entire skin surface with 3.5 to 4 MeV electron beam from a 6 MeV linear accelerator. During each weekly session, 400 rad were delivered to the entire skin and a complete course consisted of 4-6 consecutive weekly sessions. The majority of patients have been previously treated elsewhere for various periods and all patients have been at risk for a median of 12 months, range from 12-117 months following TSEB. Striking predominance of the diffuse pattern (76%) was demonstrated in both the PCL and SCL. There was extracutaneous involvement in 63% (13/22) of the PCL, nodal or visceral at onset of TSEB; median follow-up was 24 months, range 6-117 months; 20/22 (90%) of all patients obtained prompt relief of symptoms and complete regression of cutaneous lesions. Duration of cutaneous remission ranged from 6-96 months, median 18 months; in general, duration was adversely influenced by the presence of visceral involvement at onset of TSEB. Although cutaneous response among the patients with SCL and leukemia was equally good, many of these patients were treated for palliation because of rapid progression of their disease. Once weekly treatments were highly effective, well-tolerated and no untoward immediate or late effects have been noted in the bone marrow or normal skin irradiated.

Regulation of adenylate cyclase and cyclic AMP phosphodiesterase by 5-hydroxytryptamine and calcium ions in blowfly salivary-gland homogenates

Salivary-gland homogenates contain 5-hydroxytryptamine-stimulated adenylate cyclase. Half-maximal stimulation was obtained with 0.1 microM-5-hydroxytryptamine in the presence of added guanine nucleotides. Gramine antagonized the stimulation of cyclase caused by 5-hydroxytryptamine. In the presence of hormone, guanosine 5'-[gamma-thio]triphosphate produced a marked activation of adenylate cyclase activity. Stimulation of adenylate cyclase by forskolin or fluoride did not require the addition of guanine nucleotides or hormone. In the presence of EGTA, Ca2+ produced a biphasic activation of cyclase activity. Ca2+ at 1-100 microM increased activity, whereas 2000 microM-Ca2+ inhibited cyclase activity. The neuroleptic drugs trifluoperazine and chlorpromazine non-specifically inhibited adenylate cyclase activity even in the absence of Ca2+. The cyclic AMP phosphodiesterase activity in homogenates was not affected by Ca2+ or exogenous calmodulin. This enzyme was also inhibited by trifluoperazine in the absence of Ca2+. These results indicate that Ca2+ elevates adenylate cyclase activity, but had no effect on cyclic AMP phosphodiesterase of salivary-gland homogenates.

Uptake of 1:2-14C-choline by the guinea-pig lung in vitro: and the effects of p-terphenyl hemicholinium-3

1. The perfused guinea-pig lung in vitro released a total of 290 +/- 24 nmol choline after 65 min. At the end of perfusion, there were 525 +/- 36 nmol choline and 11.6 +/- 0.5 mg lecithin per g of lung tissue. 2. When perfused with 1:2-(14) C-choline at 20 nmol (20 nCi)/ml for 70 min, the level of choline in the perfusion fluid remained at 20 nmol/ml; but 65% of radioactivity was abstracted by the lung. 21% of the sequestered radioactivity was in choline phospholipids, chiefly lecithin. 3. The p-terphenyl analogue of hemicholinium no. 3 (TPHC-3), when added into the perfusion fluid at concentration 30 nmol/ml, increased significantly both the 14C-choline uptake and the conversion of 14C-choline to 14C-lecithin in the lung. However, it did not change the total tissue concentration of choline and lecithin in the lung. 4. The lung seems to have separate uptake and release mechanisms for choline and these are in equilibrium. 5. The effects of TPHC-3 on the lung in this study may be secondary to its respiratory depressant action.

Estimation of lecithin in rabbit tissues

1. A simple method for lecithin estimation was developed. Phospholipids in rabbit tissues were extracted with chloroform and methanol. 2. The samples were chromatographed with eluting solvent system; chloroform:methanol:glacial acetic acid:water (100:25:8:1.1). Lecithin was identified by the spray reagent as blue spots and the intensities were quantitated with a densitometer. 3. The concentration of lecithin in the various rabbit tissues varied from 2.8 to 10 mg/g tissue. The sequence of increasing lecithin concentration was heart less than kidney less than lung less than liver less than brain. 4. Recovery experiments of added lecithin into the tissues showed a recovery of 91-104%.

Phenytoin and phenobarbitone plasma level-dose relationships in Chinese epileptic children in Singapore

In a study of 30 Chinese epileptic children, 43% had poor seizure control. The average daily dose of phenytoin was 6.1 +/- 0.53 mg/kg, and the mean plasma level was 4.2 +/- 0.63 microgram/ml, as determined by the enzyme immunoassay (EMIT) method. The phenytoin plasma level (microgram/ml) versus daily dose (mg/kg) ratios in 73% of these patients were below 1. The average daily dose of phenobarbitone was 5.1 +/- 0.36 mg/kg, and the mean plasma level was 24.8 +/- 1.7 microgram/ml -- also estimated by EMIT. Only one patient showed adverse effects. Poor seizure control in patients was chiefly due to subtherapeutic concentrations of phenytoin, which cannot be attributed to poor patient compliance. The presence of phenobarbitone might have accelerated phenytoin metabolism, or the drug could have been lost through sweating. The pharmacokinetics of phenytoin in these Chinese children may be genetically different and might have caused the subtherapeutic phenytoin levels.

Synovial biopsy by Franklin--Silverman needle

Franklin-Silverman needles, commonly used for liver biopsies, were used for biopsy of synovia of 75 joints. The results indicate a higher percentage of success in obtaining pathologic specimens than with previously reported instruments. Complications were rare, with only milk transient hemarthrosis being found in 5 cases. For an accurate diagnosis, multiple specimens should be obtained since single specimens are too small to interpret histopathologically. Being simpler and safer, the Franklin-Silverman needle biopsy is recommended as a routine procedure for early diagnosis of synovial diseases of the joint in conjunction with joint aspiration. The success rate depends not only on the type of needle used but also on the proper selection of the biopsy site.

Cardiovascular effects of benzquinamide

The cardiovascular effects of benzquinamide were evaluated in anesthetized dogs. Intravenous benzquinamide, 0.5 to 5 mg/kg, caused tachycardia, elevated blood norepinephrine levels, frequent ventricular arrhythmias, and brief hypotension. Ganglionic blockade by hexamethonium prior to administration of benzquinamide prevented the tachycardia and alterations in norepinephrine levels but prolonged the period of hypotension. In isolated mesenteric arterial preparations benzquinamide interfered with contractile force generated by potassium chloride, norepinephrine, and prostaglandin F2 alpha. It is concluded that benzquinamide directly relaxes vascular smooth muscle thereby producing in vivo reduced peripheral vascular resistance and hypotension, which are compensated for by reflex sympathetic activation.

Patients' comments on psychiatric inpatient treatment experiences: patient-therapist relationships and their implications for treatment outcome

Only few researchers pay systematic attention to what patients may have to say about their treatment experience during psychiatric hospitalization. This study not only delineates the various therapeutic aspects of an open psychiatric inpatient unit based on the patients' comments, but also attempts to correlate the data with the objective outcome of treatment rated clinically by the therapists and independently by the author. Positive patient-therapist relationship has been found to be the most significant factor correlated closely with the treatment outcome. The correlation may support the relevance of the patients' comments regarding subjectively perceived therapeutic benefits vs. objective actual benefits.

Effect of reductive alkylation of the epsilon-amino group of lysyl redsidues of casein on its nutritive value in rats

Casein epsilon-aminolysyl residues were converted to the methyl (and dimethyl), isopropyl or cyclopentyl derivatives in high yield with formaldehyde, acetone or cyclopentanone, respectively, in the presence of sodium borohydride. When incorporated into diets at 10% as the sole protein source, the chemically modified caseins failed to support growth of young rats. Methyl casein did, however, support limited growth after about 5 days. Plasma threonine levels increased and lysine levels decreased markedly in rats fed the alkyl caseins. The respective alkyllsine derivatives were present in plasma and urine. In another experiment, nearly normal or normal growth was obtained by feeding lysine-supplemented methyl or isopropyl casein, respectively. A preparation of partially methylated casein, containing approximately equal amounts of monomethyl- and dimethyllysines, supported normal rat growth. These results demonstrate that lysine deficiency was produced by feeding highly alkylated caseins. Digestibility of the chemically modified caseins in vivo was not affected, although in vitro studies with trypsin and alpha-chymotrypsin showed lowered digestibility. Since no apparent toxicity was observed limited methylation of food proteins may be useful for protection of lysyl residues against deteriorative reactions during processing and storage.