Prediction of local cooling rates and cell survival during the freezing of a cylindrical specimen

A finite element numerical model was implemented to simulate the freezing process of an aqueous salt solution in a cylindrical container. Local cooling rates within the container were computed for several defined cooling protocols applied at the boundary. Characteristic cell survival signatures were used to predict the associated local survival rates throughout the system. These calculations show that there are two definite time domains during a typical freezing process: (1) while the surface temperature is changing and (2) after the surface temperature reaches a constant storage value. The calculations also show significant spatial variations in the local cooling rates within the container and considerable local deviation from the volumetric average survival for various simulated freezing protocols.

Endobronchial metastasis of malignant melanoma, diagnosed by bronchoscopy--report of a case

Endobronchial metastasis occurs in about 2% to 5% of patients dying of solid tumors of extrathoracic origin. These metastatic tumors can simulate bronchogenic carcinoma and presenting symptoms include cough, hemoptysis, dyspnea and wheezing. In most cases of endobronchial metastasis, the histologic finding of the bronchoscope biopsy suggests the correct diagnosis. There are only a few reports of endobronchial metastasis from malignant melanoma. We report a case of malignant melanoma with endobronchial metastasis presenting with hemoptysis simulating primary bronchogenic carcinoma.

Diagnosis of viral hepatitis

Acute viral hepatitis is a serious infectious disease of the liver caused by several viruses and characterized by acute necrosis of hepatocytes and inflammation. In this article, recent advances in hepatitis serology and virology are briefly reviewed, and practical, up-to-date laboratory tests are outlined.

Childhood renal diseases in Korea. A clinicopathological study of 657 cases

Between June 1975 and March 1987, 662 renal biopsies were performed in 657 children at Seoul National University Children's Hospital. Nephrotic syndrome was the most indication for renal biopsy and accounted for 62% of all cases. Of these, 57% showed minimal change lesions and 21% showed focal segmental glomerular sclerosis. Nephropathy, associated with Australia-antigen-positive hepatitis, was the most prominent cause of secondary nephrotic syndrome, and of these patients membranous nephropathy was found in 86%. Diffuse proliferative glomerulonephritis was found in 60% of patients with acute nephritic syndrome. Fifty-eight percent of children with haematuria were found to have either IgA nephropathy or Henoch-Schönlein nephritis. Fifteen children with acute renal failure were biopsied, 2 of whom had haemorrhagic fever.

ECG waveform analysis by significant point extraction. I. Data reduction

We present a new technique for automatic data reduction and pattern recognition of time-domain signals such as electrocardiogram (ECG) waveforms. Data reduction is important because only a few significant features of each heart beat are of interest in pattern analysis, while the patient data collection system acquires an enormous number of data samples. We present a significant point extraction algorithm, based on the analysis of curvature, that identifies data samples that represent clinically significant information in the ECG waveform. Data reduction rates of up to 1:10 are possible without significantly distorting the appearance of the waveform. This method is unique in that common procedures help in both data reduction as well as pattern recognition. Part II of this work deals specifically with pattern analysis of normal and abnormal heart beats.

ECG waveform analysis by significant point extraction. II. Pattern matching

From a set of significant points which characterizes the ECG waveform, the pattern matching algorithm detects and classifies QRS complexes. R waves are detected from the analysis of global curvature. Next, the morphology of the QRS complex is determined. QRS complexes with different morphologies are classified by a correlation algorithm. This method is sensitive to changes in shape, such as that of abnormal QRS complexes. The algorithm should be useful in automated analysis of waveforms, such as ECG signals recorded in clinical environments.

Solid-phase extraction of chloramphenicol with graphitized carbon black

The sorption and desorption properties of graphitized carbon black (GCB) were evaluated for enrichment of highly polarizable chloramphenicol (CP) from biological fluids. The distribution of CP between GCB and water lay strongly toward GCB. Among the organic solvents examined, methanol gave the lowest adsorption coefficient. The optimum packing amount of GCB, and the optimum volume and flow-rate of the eluent were deduced from the breakthrough curve and methanol elution curve, respectively. The inner diameter of GCB extraction columns was chosen from the sorption efficiency curve obtained by plotting CP recovery against column inner diameter. The solid-phase extraction method using GCB was applied to the assay of CP in serum samples in the concentration range of 5 to 50 micrograms/ml.

Intramural sparganosis manifested as intestinal obstruction--a case report

A case of intramural sparganosis of jejunum presenting as intestinal obstruction is described. Resected intestine from a 48 year old man with acute abdomen revealed a degenerated sparganum in the submucosa with typical tissue reaction and extensive edema. The tissue reaction was basically granulomatous, consisting of layers of inner palisading histiocytes and outer mononuclear cell infiltration. Many calcospherules were prominent within the degenerated worm. Eosinophil infiltration was scanty.

IgA nephropathy in Korea: a morphological and clinical study

IgA nephropathy (IgA N) is the most common type of primary glomerulonephritis (27.5%) in South Korea and leads to renal failure in a significant number of cases. To evaluate the possible prognosticators of this disease, renal biopsy material from 142 Korean patients with IgA N was studied by light-, electron- and immunofluorescent microscopy, and a clinicopathologic correlation was made. Modified classification of Meadow et al. [1972] for Henoch-Schoenlein nephritis was adopted for the histologic grading of glomerular lesions. Twenty-three biopsies (16.2%) exhibited histologic grades IV and V lesions in association with high levels of proteinuria, serum creatinine and blood pressure and a low frequency of gross hematuria when compared to the remaining 119 biopsies with histologic grades I to III lesions. Ninety-one patients were followed for one to 6.5 years (mean, 3.4 years). Seventeen patients (18.7%) had chronic renal insufficiency, of whom eleven eventually showed endstage renal failure. More than 70% of the patients with histologic grades IV and V exhibited progressive renal disease, whereas patients with grades I to III lesions had a benign course (p less than 0.0005). These results suggest that histologic grading may be the best index to predict the present state or the subsequent progression of the lesion in IgA N.

Measurement of free and bound malondialdehyde in vitamin E-deficient and -supplemented rat liver tissues

The quantity of free malondialdehyde (MDA) in liver tissues of rats fed vitamin E-deficient or -supplemented diets for 43 wk was measured by a newly developed high performance liquid chromatographic (HPLC) method. Bound MDA was quantified by the same HPLC method after alkaline hydrolysis of tissue homogenates. Tissues from vitamin E-deficient animals showed levels of free MDA about 15 times higher but levels of bound MDA less than 2 times higher than the vitamin E-supplemented animals. Free MDA is the major form in vitamin E-deficient tissues, but bound MDA is predominant in vitamin E-supplemented tissues. Conventional thiobarbituric acid (TBA) test results revealed that the content of TBA-reactive substances expressed in MDA equivalents was much higher than the actual free MDA levels in all groups. Results indicate that free MDA level measured by HPLC is a more sensitive index than the TBA value for lipid peroxidation. Some other TBA-reactive substances seem to exist in liver tissue regardless of the dietary treatment.

Specificity of enzyme immunoassay for hepatitis B core antibody used in screening blood donors

Hepatitis B core antibody (anti-HBc) is currently tested by a competitive inhibition enzyme immunoassay (EIA), using recombinant DNA-produced core antigen. We have used the anti-HBc assay in routine screening of voluntary blood donors in San Francisco. The detection rate of anti-HBc was 2.08 percent. The specificity of the antibody test was established by an absorption method using purified HBc antigen (HBcAg) produced by recombinant DNA technology and covalently coupled to Sepharose 4B. Bovine serum albumin was used in the preparation of a control conjugate. The absorption test demonstrated that out of 98 anti-HBc-positive specimens, 97 could be specifically neutralized. Only one specimen was indeterminate. The absorption test was particularly useful in confirming the specificity of EIA in eight specimens inconsistently positive for anti-HBc. We conclude that the current EIA for anti-HBc is highly specific and we are of the opinion that it could be used as a rational basis for donor deferral since it gives evidence of active or previous HBV infection.

Absorption of mercuric sulphide following oral administration in mice

Mercuric sulphide or its counterpart cinnabar occurring in nature has long been associated with Chinese traditional medicine. Because of the reputed insolubility of this compound it has been assumed that it would not be significantly absorbed from the gastrointestinal tract after oral administration. In this study groups of mice were fed a diet containing either mercuric sulphide or cinnabar. Their urine was collected on alternate days for a 1-week period at the end of which they were killed and their livers and kidneys assayed for mercury by atomic absorption spectrophotometry. The mercury contents in their urine and organs were found to be significantly higher compared to control mice (P less than 0.001) indicating that significant absorption of mercury from the gut has occurred.

Henoch-Schoenlein nephritis in adults: a clinical and morphological study

Renal prognosis is not clear in adults with Henoch-Schoenlein nephritis (HSN). Renal biopsy material from seventeen adult patients with HSN was studied by light-, electron-, and immunofluorescent microscopy, and a clinicopathologic correlation was made. The outstanding glomerular lesion was a mesangial IgA deposition, apart from the proliferative glomerulonephritis associated with segmental lesions or crescents. At the time of biopsy five patients (29%) presented with renal insufficiency complicated by nephrotic syndrome and/or hypertension. After a mean follow-up period of 3.2 years, ten patients showed complete recovery, two had minor urinary abnormalities, and five exhibited moderate proteinuria with or without hematuria. No patients had died nor developed chronic renal failure. Our data indicate that the outcome of HSN in adults is favorable similar to that in children. No initial clinical nor pathological features could be associated with a poor prognosis in this study. Further follow-up is needed in view of the unpredictable nature of this disease.

Economical modification of a radioimmunoassay of digoxin with negligible interference from cord and neonatal sera

The Amerlex digoxin radioimmunoassay was modified to reduce the running cost by five times. The modified method compared well with the original method (y = 1.0138x + 0.00916, r = 0.9936). Using the modified method, the performance with the American Association for Clinical Chemistry quality control program was consistently satisfactory for 1 year. When normal cord and neonatal sera were tested with the modified method, 41% of the 22 samples of cord serum and 68% of the 19 samples of neonatal serum produced digoxin levels less than or equal to 0.05 ng/ml. The highest digoxin level produced by cord and neonatal sera was 0.3 ng/ml.

Acute tolerance to diazepam in mice: pharmacokinetic considerations

The tolerance to the hypnotic effect of diazepam developed after a single exposure to diazepam in the presence or absence of cycloheximide, which blocks liver enzyme induction, was studied. At the high dose (30-35 mg/kg) used in this study, diazepam was found to be metabolized very rapidly in mice, consistent with previous findings using a much smaller dose (5 mg/kg). There was no significant difference in the pharmacokinetics of diazepam in control and tolerant mice as observed by monitoring the plasma and brain concentrations of diazepam and N-desmethyldiazepam. It is concluded that acute tolerance to diazepam in mice may not be attributed to changes in pharmacokinetic factors.

Molecular characterization of chromosomal genes affecting double-stranded RNA replication in Saccharomyces cerevisiae

We cloned MAK11, MAK18, and MKT1 utilizing their genetic map positions. The MAK11 gene is close to CDC16 on chromosome XI. Both genes were cloned on a single 7-kb fragment, and both have now been sequenced. The MAK18 gene is located close to PET3 on chromosome VIII. A large plasmid carrying PET3 was obtained from R. Elder and R.E. Esposito and was found to also have the MAK18 gene. The MAK16 gene has been subcloned and sequenced starting with a clone provided by J. Crowley and D. Kaback. The MKT1 gene was mapped near the gene for topoisomerase II. The topoisomerase II clone was used as the starting point for chromosome-walking to isolate MKT1. A deletion-insertion mutation (disruption) of MKT1 results in an inability to maintain M2, but does not affect M1 or L-A maintenance. Clones of SKI3 and SKI8 were selected using the cold sensitivity for cell growth of ski- M1 strains. The SKI8 gene was disrupted and found to be nonessential for cell growth in the absence of M double-stranded RNA (dsRNA). The SKI3 and SKI8 genes were mapped using these clones. We have also obtained other clones suppressing the pathology caused by the high M titer in ski- strains. These clones are not the SKI genes themselves but somehow avoid the growth defect without repressing M copy number.

Prognostic evaluation of endoscopic sclerotherapy on bleeding esophageal varices

From November 1981 to March 1984, 100 patients with esophageal varices bleeding were treated by endoscopic sclerotherapy.

The combined peri and intravasal method was applied, using Äthoxysclerol as a sclerosant.

The 79 cases were followed after sclerotherapy over a period ranging from 3 months to 26 months.

The amount of transfused blood on presclerotherapy was 4–5 pints and in 2/3 cases 1–2 pints were needed on postsclerotherapy.

Seven cases (8.1 per cent) had complications; 2 cases developed esophageal stenosis, 3 cases aspiration pneumonia, and 2 cases mediastinitis.

Fortunately, all 7 cases recovered. Rebleeding occurred in 15 cases (19.0 per cent); namely 3 cases (3.8 per cent) within 6 months, 5 cases (6.3 per cent) in the period from 6 months to 12 months and 7 cases (8.9 per cent) after 12 months.

During the follow up period, 14 cases died. Their causes of death were as follows: 6 cases died of hepatic failure, 5 cases died of hepatoma, and 3 cases expired from uncontrollable bleeding.

Based on data, it appears to be possible to control the bleeding in 97 per cent of the esophageal varices bleeding on their (first) bleeding.

Simultaneous estimation of serum concentrations of dapsone, monoacetyldapsone, and pyrimethamine in Chinese men on maloprim for malaria prophylaxis using reversed-phase high performance liquid chromatography

A reversed-phase high performance liquid chromatography method was developed to simultaneously estimate serum concentrations of dapsone (DDS), monoacetyldapsone (MADDS), and pyrimethamine (PYR) in 34 young adult Chinese men after they had taken the sixth weekly dose of Maloprim for malaria prophylaxis. Serum concentrations of DDS, MADDS, and PYR after 24 h were (mean +/- SEM) 374 +/- 31.3, 310 +/- 30.4, and 121 +/- 7.9 ng/ml, respectively. The 72-h serum concentrations of DDS, MADDS, and PYR were (mean +/- SEM) 134 +/- 21.6, 115 +/- 17.9, and 80 +/- 7.2 ng/ml, respectively. Serum concentrations of DDS and MADDS in many subjects after 120 h were less than 20 ng/ml, while mean +/- SEM concentration of PYR was 53 +/- 5.6 ng/ml. Acetylator phenotyping of the subjects showed that there were 31 (91%) fast acetylators, three (9%) intermediate acetylators, and no slow acetylators.

Inhibition of acetylcholinesterase by histamine agonists and antagonists

The histamine H1 and/or H2-receptor agonists showed weak acetylcholinesterase inhibitory activity. Their dissociation constants (Kis and/or Kii) were 2-methyl histamine (Kis = 1751 mumol/l, s.e. = 163) less than 4-methyl histamine (Kis = 3551 mumol/l, s.e. = 414) less than dimaprit (Kis = 2931 mumol/l, s.e. = 605; Kii = 3668 mumol/l, s.e. = 901) less than histamine (Kis = 6480 mumol/l, s.e. = 1360). Both histamine H1 and H2-receptor antagonists showed stronger acetylcholinesterase inhibitory activity. Their dissociation constants were ranitidine (Kii = 1.56 mumol/l, s.e. = 0.14) less than oxmetidine (Kis = 14.7 mumol/l, s.e. = 1) less than mepyramine (Kis = 178 mumol/l, s.e. = 23; Kii = 440 mumol/l, s.e. = 98) less than cimetidine (Kis = 199 mumol/l, s.e. = 12; Kii = 827 mumol/l, s.e. = 126). Using the ROSFIT programs for fitting data to common enzyme kinetic models, the inhibition caused by histamine, 4-methyl histamine, 2-methyl histamine, oxmetidine and neostigmine was of the competitive type. Mepyramine, cimetidine and dimaprit appeared to exhibit the modern non-competitive type of inhibition with their primary action on the enzyme rather than on the enzyme-substrate complex. Ranitidine seemed to act on the enzyme-substrate complex rather than the enzyme, conforming to the uncompetitive inhibition model. The clinical implications of acetylcholinesterase inhibition by cimetidine and ranitidine are discussed.

Ceftriaxone therapy in bacteremic typhoid fever

The efficacy and safety of ceftriaxone in the treatment of bacteremic typhoid fever was studied in 14 patients. Ceftriaxone at a dosage of 50 to 60 mg/kg per day was administered intravenously in two divided doses in 13 patients and as a single dose in 1 patient. When the two patients with medical complications causing persistent fever and the patient who was febrile during therapy were excluded from the calculations, the mean period of defervescence was 4 days. Five to eight days of ceftriaxone therapy was adequate for the patients who were cured. The 14 patients treated with ceftriaxone included 13 patients who were considered cured, although 1 was a convalescent carrier, and one patient who was a treatment failure. There were no relapses in the 11 patients who were monitored for 1 to 8 months. Both peak and trough concentrations of ceftriaxone were well above the ceftriaxone MICs for the Salmonella typhi strains isolated from the patients. We have demonstrated that ceftriaxone can be used successfully in the treatment of typhoid fever in some patients. The advantages of its use include rapid clinical response, short course of treatment, and lack of serious adverse drug reactions.

Ganglion blocking activity of cimetidine in the anaesthetized cat

Cimetidine produced a dose-dependent and reversible inhibition of contractions of the nictitating membrane elicited through stimulation of the preganglionic nerve supplying the superior cervical ganglion in the anaesthetized cat. Postganglionic nerve stimulation resulted in only a slight and variable inhibition of the contractions. Both hexamethonium and cimetidine also produced a dose-dependent and reversible fall in arterial blood pressure. The ganglion blocking activity of cimetidine was much weaker than that of hexamethonium; the ED50 ratio (cimetidine:hexamethonium) calculated from the cumulative log dose-response curves for the two drugs was 64. The possible mechanism(s) of ganglion blockade produced by cimetidine is discussed including a possible action at nicotinic receptors, either directly or indirectly (via its anticholinesterase activity), and ion channel blockade. The clinical implications of cimetidine-induced ganglionic blockade are also discussed, especially with respect to sexual impotence associated with the use of cimetidine.

A comparative study of the use of choline theophyllinate and a sustained-release theophylline in adults with chronic asthma

We studied 16 adults with chronic bronchial asthma by measuring the plasma theophylline concentrations and evaluating clinically the control of asthma following oral administration of choline theophyllinate (CT) and a sustained-release theophylline preparation (SRT). All 16 patients were studied in 3 one-weekly phases. These patients received CT 200 mg t.i.d. during the 1st week, no theophylline during the 2nd week and SRT 250 mg 12-hourly during the 3rd week. All other anti-asthmatic medications were maintained during the study. After the night dose of a theophylline preparation, the mean plasma trough concentration the next morning was significantly higher for SRT (9.4 mcg/ml +/- SEM 1.0) than for CT (3.6 mcg/ml +/- SEM 0.6). The mean plasma peak concentration after the morning dose was also significantly higher for SRT (11.5 mcg/ml +/- SEM 1.0) than for CT (7.4 mcg/ml +/- SEM 1.0), The mean forced expiratory volume in one second (FEV1) obtained during SRT treatment was significantly higher than during CT treatment. There was no significant difference between FEV1 measured at trough concentrations during CT treatment and during the period without theophylline. The patients had fewer symptoms of asthma and fewer side-effects from theophylline during the week they received SRT compared with the week they received CT. In this study, using the conventional dosage schedule as practised in Singapore, SRT has distinct advantages over CT in the treatment of chronic asthma.

Anticholinesterase activity of and possible ion-channel block by cimetidine, ranitidine and oxmetidine in the toad isolated rectus abdominis muscle

Responses of the toad isolated rectus abdominis muscle to cumulative doses of acetylcholine were recorded in the absence or presence of varying concentrations of cimetidine, ranitidine or oxmetidine. The corresponding cumulative log concentration-response curves for acetylcholine were then plotted for each antagonist studied. Cimetidine (5 mmol/l), ranitidine (1 mmol/l) and oxmetidine (0.02 mmol/l) potentiated the effect of acetylcholine by 4-fold, 2.6-fold and 1.3-fold, respectively. At higher concentrations all three histamine H2-receptor antagonists produced a concentration-dependent and non-parallel shift of the acetylcholine curve to the right of the corresponding control curve accompanied by a depression of the maximal response. The results provide further evidence that the H2-antagonists studied possess anticholinesterase activity and also suggest that the H2-antagonists may produce neuromuscular blockade by ion-channel block. The clinical implications of the results obtained are also discussed.

A renal biopsy study of lupus nephropathy in the United States and Korea

A comparative study was made using renal biopsy specimens obtained from US and Korean patients with lupus nephropathy. Significant differences were observed in the morphologic distribution and activity of the disease. Korean patients exhibited a higher frequency of World Health Organization class IV lupus nephropathy (77.8%) than black (47.2%) or white (42.1%) US patients (P less than 0.025, P less than 0.05, respectively), and a higher inflammatory intensity index (P less than 0.045) than US patients. Korean patients also showed a significantly lower frequency of WHO class III nephropathy (P less than 0.05). No significant morphologic differences were seen between the US white and black patient populations. These data suggest that the Korean patients had a more active and potentially more fulminating disease than the US patients. Whether differences in genetic and external causative factors play a role in the observed differences in renal histopathology among these groups remains to be clarified.

Significance of renal hyaline arteriolosclerosis in focal segmental glomerulosclerosis

The renal biopsy findings of 60 adults with idiopathic focal segmental glomerulosclerosis (FSGS) were reviewed in order to determine the clinicopathological significance of renal hyaline arteriolosclerosis (HA) in FSGS. 36 biopsies (60%) exhibited a definite HA [HA (+)] in association with high levels of proteinuria (p less than 0.0024) and serum creatinine (p less than 0.0316) and a high frequency of global sclerosis (p less than 0.0014) when compared to the remaining 24 biopsies without definite HA [HA (-)]. 14 (39%) of these HA (+) biopsies showed continuity of afferent arteriolosclerosis with hyalinosis of the adjacent glomerular axial segmental sclerosis. These results suggest that HA (+) patients with FSGS show more severe disease than HA (-) patients, and there is a possible relationship between FSGS and HA.

Immunoreactive pro-enkephalin and prodynorphin products are differentially distributed within the nucleus of the solitary tract of the rat

In this study we examined the distribution of two different endogenous opioid peptides in the nucleus of the solitary tract of the rat medulla. As a marker for immunoreactive enkephalin, we used an antiserum directed against one of the proenkephalin products, methionine enkephalin-arg-gly-leu (m-Enk). To identify immunoreactive dynorphin we used an antiserum directed against the prodynorphin product, dynorphin B (Dyn B). The PAP method was used on both colchicine and normal animals. Caudal to the obex, within the commissural nucleus, there is extensive overlap of both immunoreactive m-Enk and Dyn B terminals and cells. While the cells are morphologically similar, the immunoreactive dynorphin cells are somewhat larger. Rostral to the obex, there is a marked difference in the distribution of the two compounds. Immunoreactive m-Enk terminals are concentrated medial to the solitary tract; there is minimal staining laterally. In contrast, immunoreactive Dyn B terminals are concentrated lateral to the solitary tract. The rostral cellular distribution of the two opioid peptides follows a similar pattern. The morphology of the medially located m-Enk and laterally located Dyn B cells is also readily distinguished. The former are small, round cells with minimal dendritic labelling; the latter are larger, pyramidal neurons with prominent apical and basal dendrites. Since the medial and lateral nuclei of the solitary tract have been associated with cardiovascular and respiratory control, respectively, these data suggest that different endorphin families have different functional actions within the nucleus of the solitary tract.

Course of renal pathology in patients with systemic lupus erythematosus

Evaluation of the course of lupus nephropathy by serial kidney biopsy in 50 patients revealed a complex pattern of transitions from one histologic class to another. A high rate of transformations (56 percent) was observed, with fewer than half the patients remaining in the original category. Although the general trend was towards transformation to a less severe lesion (WHO classes III and IV transforming into classes II and V), this was certainly not the rule for all individual classes. These transformations were rarely predictable on the basis of available clinical, laboratory, or pathologic information, and were less common in younger patients. These results help clarify the pathologic behavior of lupus nephropathy in the modern therapeutic era and highlight the value of pathologic examination for the planning and evaluation of therapy in selected patients.

Wedge-shaped BGO scintillation crystal for positron emission tomography: concise communication

In order to increase the detection efficiency and also reduce the interdetector spillage, a new wedge-shaped BGO scintillation detector array is proposed. By shaping the front part of a detector as a wedge, the absorption path becomes longer, particularly for obliquely incident photons, thereby improving the uniformity in the sensitivity for the incident photons of different angles. To demonstrate the effectiveness of the proposed detector shape, a Monte Carlo simulation was performed and the results are presented.

The effect of intermediate filament inhibitors on steroidogenesis and cytoskeleton in Y-1 mouse adrenal tumor cells

When Y-1 mouse adrenal tumor cells were treated with sodium orthovanadate, an agent disrupting BHK21-F cell microtubule-intermediate filament (IF) interactions, there was no change in the amount of 20-dihydroprogesterone produced. A neurofilament-microtubule perturbing agent, beta,beta-iminodipropionitrile (IDPN), enhanced the ability of Y-l cells to produce steroid in response to ACTH by acting on the plasma membrane. Electron microscopy of Y-l cells extracted with Triton X-100 revealed that both vanadate and IDPN caused the aggregation of granular structures in the perinuclear area. Based on the steroidogenic effects of IDPN, perinuclear granule aggregation may result from an altered interaction between intermediate filaments, microtubules and the plasma membrane. The reason for the ultrastructural changes caused by vanadate is unknown.

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.