Tc-99m HMPAO WBC imaging to detect carditis and to evaluate the results of high-dose gamma globulin treatment in Kawasaki disease

Eighteen patients with Kawasaki disease and suspected carditis (11 boys, 7 girls, mean age 18 months) in acute stages underwent Tc-99m HMPAO WBC imaging of the heart. Signs and symptoms subsided after conventional aspirin therapy and the intravenous injection of high-dose (400 mg/kg per day for 5 days) gamma-globulin treatments. Tc-99m HMPAO WBC imaging of the heart was arranged a second time to evaluate the effects of the treatments for carditis. The results showed that a significant difference existed in the severity of carditis before and after the treatments (P less than 0.001, by signed rank test), 39% (7/18) with significant improvement in severity of carditis, 50% (9/18) without definite change. However, 11% (2/18) became more severely ill after the treatments. Tc-99m HMPAO WBC imaging may be useful in detecting carditis in Kawasaki disease and in evaluating the effects of aspirin plus the newly recommended gamma-globulin for the treatment of carditis in Kawasaki disease.

99Tcm-HMPAO-labelled white blood cell scanning for the detection of carditis in the differentiation of rheumatic fever and inactive rheumatic heart disease in children

Myocardial imaging with 99Tcm-hexamethylpropylene amineoxime (HMPAO)-labelled white blood cells (Tc-WBC) was used to detect carditis and differentiate rheumatic fever (RF) and inactive rheumatic heart disease (IRHD). Ten cases of RF and 15 cases of IRHD were studied, and the results revealed 60% (6/10) of the cases of RF with carditis, but none of the cases (0/15) of IRHD with carditis. There was significant difference (P less than 0.05, by Fisher's test) between RF and IRHD. In our preliminary conclusion, Tc-WBC heart scanning may be a noninvasive method for evaluating the existence of carditis in cases of RHD and in the differentiation of RF and IRHD.

Tc-99m HMPAO labeled WBC scan for the detection of myocarditis in different phases of Kawasaki disease

Myocardial imaging with Tc-99m HMPAO WBC was used to detect myocarditis of Kawasaki disease in 103 infants and children (66 boys and 37 girls, mean age 3 years and 4 months). The clinical course of Kawasaki disease may be divided into three phases, from the onset of illness onset until all clinical symptoms and signs have disappeared. Twenty-four hour myocardial imaging was performed in anterior, LAO, and left lateral views. The grading system was as follows: score 0 less than bone uptake; 1 = bone uptake; 2 greater than bone uptake; and 3 greater than or equal to liver uptake. If the score was greater than or equal to 2, significant myocarditis was considered. The appearing ratio of myocarditis was 57% (13/23) in the first phase; 65% (15/23) in the second phase; 54% (31/57) in the third phase. No significant difference was demonstrated among the three groups of patients (P greater than 0.1, by Chi-square test). In conclusion, an occult myocarditis may continue in all three phases of Kawasaki disease, even if the clinical symptoms and signs had improved by the evidence of Tc-99m HMPAO labeled WBC scan to avoid advanced cardiac complication.

The effects of epidermal growth factor and chondroitin sulfate on the animal corneal endothelial cell culture

In order to investigate the effects of different culture media containing various concentrations of epidermal growth factor (EGF) and chondroitin sulfate (CDS) on the growth of cultured corneal endothelial cell, pig corneal endothelial cells were used for this study. The cells were divided into 7 groups and each group was cultured with a medium containing: 1. Eagle's minimal essential medium with Earle's salt (EMEM) only; 2. EMEM + EGF (10 ng/ml); 3. EMEM + EGF (100 ng/ml); 4. EMEM + CDS (1 mg/ml); 5. EMEM + CDS (25 mg/ml); 6. EMEM + EGF (10 ng/ml) + CDS (1 mg/ml); 7. EMEM + EGF (100 ng/ml) + CDS (25 mg/ml), respectively. The results are shown below: (1) High concentration of EGF (100 ng/ml) stimulated the growth of pig corneal endothelial cells, shortened doubling time and the cells reached confluence earliest in group 3. But a low concentration of EGF (10 ng/ml) showed no effects on the growth of pig corneal endothelial cells. (2) A high concentration of CDS (25 mg/ml) might retard the growth of pig corneal endothelial cell, but a low concentration of CDS (1 mg/ml) has no retarding effects on the growth of pig corneal endothelial cells. (3) A high concentration of EGF could "antagonize" the CDS induced growth retarding effects of endothelial cells. (4) Those cells cultured with a medium containing high concentrations of EGF had more mitotic activity, including many prominent binuclear and polynucleolar cells. (5) The cells cultured with a medium containing high concentrations of CDS showed a more flat-shaped morphology under observation with a phase contrast microscope.(ABSTRACT TRUNCATED AT 250 WORDS)

Decreased norepinephrine release in anterior hypothalamus of NaCl-sensitive spontaneously hypertensive rats during high NaCl intake

We previously demonstrated that dietary NaCl supplementation reduces endogenous norepinephrine stores and turnover in the anterior hypothalamic area (AHA) of male NaCl sensitive spontaneously hypertensive rats (SHR-S) but not in NaCl resistant control rats and have implicated this mechanism in the pathogenesis of NaCl sensitive hypertension. In the current study, we tested directly the hypothesis that dietary NaCl supplementation decreases the release of norepinephrine from nerve terminals in the AHA of SHR-S using the push-pull perfusion technique. Conscious, freely moving SHR-S and control Wistar-Kyoto (WKY) rats were studied after 2-3 weeks of 8% or 1% NaCl feeding. In the 1% NaCl fed SHR-S, 3-methoxy-4-hydroxyphenylglycol (MOPEG, the major metabolite of norepinephrine in brain) levels averaged 272 +/- 32 pg/10 min; norepinephrine levels, 17 +/- 2 pg/10 min; in the 8% NaCl fed SHR-S, MOPEG levels averaged 72 +/- 7 pg/10 min; norepinephrine levels were 6 +/- 1 pg/10 min. There was a positive linear correlation (r = 0.777; P less than 0.01) between MOPEG and norepinephrine levels in AHA perfusates, indicating that perfusate MOPEG levels provide a useful index of norepinephrine release from AHA nerve terminals. In contrast, MOPEG levels in AHA perfusates were not affected by dietary NaCl intake in control WKY, and in control posterior hypothalamic perfusates, were not affected by dietary NaCl intake in SHR-S.(ABSTRACT TRUNCATED AT 250 WORDS)

[Double aortic arch associated with severe left ventricular dysfunction--a case report]

A case of a 3-month-old male infant with severe LV dysfunction and a complete double aortic arch (both arches patient) is reported. The right dominant aortic arch runs retroesophageally to the right and joins with the left smaller arch to form the descending thoracic aorta on the right side while the ligamentum arteriosum was located in its normal position (the left side). Through a left thoracotomy, the smaller left arch and the ligamentum were divided to relieve the obstruction of the trachea from compression of the vascular ring. Postoperative convalescence was good. Further follow up of this patient after 9 months showed that there was neither any respiratory failure nor any heart failure sign present, though severe LV dysfunction persisted.

Comparison of 99Tcm-HMPAO-labelled white blood cells and 67Ga citrate scans to detect myocarditis in the acute phase of Kawasaki disease

Myocardial imaging with 99Tcm-HMPAO-labelled white blood cells (WBC) and 67Ga citrate was used to detect myocarditis in the acute phase of Kawasaki disease among 22 infants and children; 18 cases of myocarditis were detected by 99Tcm-HMPAO-labelled WBC heart scans, but only one case was detected by 67Ga citrate heart scans. In conclusion, 99Tcm-HMPAO-labelled WBC scanning provides a more sensitive method than 67Ga citrate scanning in the detection of myocarditis in Kawasaki disease.

[Nemaline myopathy--a case report]

An 8-year-old Chinese girl who was noted to have feeding difficulty and poor weight gain since her infancy. Her motor development was delayed with sitting at 1-year-old and walking independently at 2-year-old. She visited our OPD when she was 8. Physically, she was thin and slender. Her height and weight were below the 10th and 3rd percentile. Her face was elongated with high arched palate. Neurologically, she had waddling gate with marked proximal muscle weakness. Her cranial nerves and sensation remained intact. Laboratory tests including blood routine, liver function, renal function, electrolytes, NCV and cardiac echo all were within normal limits. The EMG showed myopathic pattern. A fresh-frozen muscle biopsy stained with the modified Gomori trichrome, processed by histochemistry and electronmicroscopic examination showed typical nemaline rods with predominance of type 1 muscle fibers. She was then diagnosed to have nemaline myopathy.

Genetic and environmental contributions to cholesterol and its subfractions in 11-year-old twins. The Medical College of Virginia Twin Study

We conducted a cross-sectional analysis of the genetic and environmental contributions to the variance of lipoprotein cholesterol and its subfractions in children during early adolescence. Univariate path analysis was used to determine the relative contributions of genes, individual environment, and family environment to these measures in 233 11-year-old Caucasian twin pairs. For high density lipoprotein, high density lipoprotein2, low density lipoprotein, very low density lipoprotein, and triglycerides, a model that incorporated genes and individual environmental variation but not common environment was sufficient to explain the variation. Different magnitudes of genetic effects were seen for total cholesterol in boys and girls. High density lipoprotein3 showed different magnitudes by sex for genetic and individual environmental effect. Intermediate density lipoprotein was the only cholesterol subfraction in which shared, or common, environment was found to make a statistically significant contribution to the variation.

A stochastic two-stage carcinogenesis model: a new approach to computing the probability of observing tumor in animal bioassays

A new definition of probability of observing tumor in animal bioassay is developed. It is derived from a two-stage stochastic model for carcinogenesis with time-dependent birth and death rates for cell proliferation. The model takes into account the method of collecting data on preneoplastic and neoplastic lesions. The new definition is appropriate for analyzing the presence or absence of tumors in animal bioassays.

A cloned ompR-like gene of Streptomyces lividans 66 suppresses defective melC1, a putative copper-transfer gene

Expression of tyrosinase in Streptomyces requires functional MelC1 protein, which is postulated to transfer copper to apotyrosinase. We have previously isolated a mutant of Streptomyces lividans, HT32, that phenotypically suppressed mutations in cloned melC1 (H.-C. Tseng and C. W. Chen, in preparation). Plasmid pLUS132, containing an ATG to ATA transition at the initiation codon of melC1, was used for cloning the suppressor gene from HT32. A 1687 bp suppressor DNA was isolated that contained two characteristic Streptomyces coding sequences: a 217-amino-acid open reading frame (cutR) and a truncated open reading frame (cutS) downstream. Subcloning analysis attributed the phenotypic suppression activity to the putative cutR gene from HT32. The putative CutR exhibited similarity to the response regulator OmpR of the osmoregulatory signal-transduction system in Escherichia coli. The truncated CutS resembled, to a lesser degree, the N-terminus of EnvZ, the histidine protein kinase counterpart of OmpR. DNA hybridizing to the cloned cutR-cutS sequence was detected in 16 other Streptomyces species. We postulate that the putative cutR-cutS operon regulates copper metabolism in Streptomyces.

The nucleotide sequence of 3C proteinase region of the coxsackievirus A24 variant: comparison of the isolates in Taiwan in 1985-1988

Acute hemorrhagic conjunctivitis caused by coxsackievirus A24 variant (CA24v) first appeared in Taiwan in October 1985, followed by two other sequential epidemics in 1986 and 1988. In order to know the evolutionary relationship of the CA24v strains isolated in Taiwan, we first determined the nucleotide sequence of the 3C proteinase (3Cpro) region of the prototype strain (EH24/70), isolated in Singapore in 1970, by molecular cloning. The nucleotide sequence of the 3Cpro region thus sequenced showed striking homology with polioviruses and coxsackievirus A21. Viral RNA of eight isolates obtained from the three epidemics was reverse transcribed, amplified by the polymerase chain reaction, and cloned into M13 phage for the production of ssDNA for nucleotide sequencing by the dideoxy chain termination method. When the number of nucleotide difference was taken as a genetic distance between isolates, all isolates showed a very similar distance from the EH24/70, the earliest isolate of CA24v, indicating that they evolved at a constant evolutionary rate. Phylogenetic analysis by the unweighted pairwise grouping method of arithmetic average (UPGMA) indicated that the six isolates collected in 1985 and 1986 were closely related, while two 1988 isolates were more distant from them. The branching time between these two groups was estimated to be May 1984, 18 months before the first recognition of the CA24v epidemic in Taiwan. This is the first report of the nucleotide sequence of CA24v genome RNA and of an evolutionary analysis of the virus using the nucleotide sequence.

Ocular refraction and its components among younger children in Kaohsiung: a 4-year longitudinal study

A four-year longitudinal study was made on refraction and its components among 50 children of Kaohsiung, Taiwan, R.O.C. aged from 7 to 10.6 years. The methods of examination of the eyes were the same as that of four years ago, including Mydriacyl refraction, keratometry for corneal curvature radius, and ultrasonic measurement of the refractive components. One eye with amblyopia was excluded. The results of our study showed that all of our cases over 6 years of age had a corrected visual acuity of 0.8 or better, and that the refractive state shifted to myopia in our 4-year follow up. The rate of myopia increased from 2% to 27.3%. Comparisons of refractive components between the years 1983 and 1987 showed significant increases in refractive power, length of vitreous cavity and total axial length of the eyes. Corneal refractive power and lens thickness, however decreased significantly. As for differences in gender, several results were the same for both 1983 and 1987: corneal curvature radius, the length from anterior corneal surface to anterior lens surface, length of vitreous cavity and total axial length were larger in males than females. Finally, total axial length and corneal curvature radius were the factors most affecting the refractive state in younger children.

Gas-forming vertebral osteomyelitis in diabetic patients

We report 2 cases of gas-forming vertebral osteomyelitis in diabetic patients. Both were caused by gram-negative bacilli, Escherichia coli and Klebsiella pneumoniae respectively. Both ran a fulminant course to death despite appropriate parenteral antibiotics. We suggest that early surgical intervention may be needed in cases with gas-forming vertebral osteomyelitis.

Response of medullary reticular neurons of cat to off-vertical axis rotations

To investigate whether neurons in the medullary reticular formation of decerebrate cats can encode spatial orientation during 360 degrees off-vertical axis rotations (OVAR), responses of these units were studied during constant velocity OVAR in clockwise (CW) and counter-clockwise (CCW) directions. Tilt-sensitive units, some of which were activated by antidromic stimulation of the thoracic cord, were found to respond to 360 degrees OVAR with position-and direction-dependent modulation in discharge rates. For the individual responsive unit there was a difference in the spatial location of the CW and CCW discharge maxima, while a comparable response gain was obtained for rotations in either direction. The orientation of the best response of each unit was not significantly modified by changes in the amplitude of head tilt and/or velocity of rotation. Such characterized directional axes of the medullary reticular units were found to have a fairly equal distribution over the 360 degrees. The role that neurons in the medullary reticular formation plays in encoding otolith inputs with respect to head movements is discussed.

[Menkes' kinky hair disease: report of 2 cases]

Menkes' kinky hair disease (trichopoliodystrophy) is a rare inherited X-linked recessive disease with an incidence of about 1:35,000, and is rare reported previously in Taiwan. We present 2 cases with typical features including sparse, coarse and stubby, kinky hair, depigmented skin, pudgy face, arrow-shaped upper lip, hypotonia, Babinski signs bilaterally, profound psychomotor retardation with disability of head control or rolling over, and poorly controlled myoclonic jerks. Both were male infants with a family history of male relatives died in early childhood. Their hairs showed pili torti and trichorrhexis nodosa microscopically. Serum levels of copper were 14 ug/dl and 20 ug/dl. Ceruloplasmin levels were 10.4 mg/dl and less than 7 mg/dl. Their EEG showed abnormal generalized brain polyspike waves. Brain CT scan showed generalized brain atrophy, and chronic subdural hematoma in case 1. Bilateral urinary bladder diverticula and spurs over the distal ends of the femoral diaphysis were found in case 1. Normal urinary bladder was found in case 2 initially, then diverticula developed one year later. They are currently on anticonvulsants (Rivotril) therapy. Repeated attacks of respiratory infection, myoclonic seizure, hypotonia, and static neurologic developmental status are noted.

Time spent and satisfaction of new out-patients in Department of Internal Medicine. Kaohsiung Medical College Hospital

To assess the time spent and the degree of satisfaction of new clinic patients, one hundred and nine new out-patients from the Internal Medicine Clinic of Kaohsiung Medical College Hospital were studied from January 30th to February 6th, 1985. Both accurate field recording and telephone interviews concerning the time spent for each procedure and satisfaction with the medical personnel and expense in their first visits were carried out. The total time spent was 152 +/- 65 minutes (mean +/- SD) from questionnaire and 126 +/- 56 minutes from field recording. According to field recording, time spent in waiting for registration was 39.8 +/- 42.9 minutes. Most (55%) of study patients spent more than one hour in waiting for consultation. The time spent in waiting for filling prescription was 17 +/- 6 minutes. The accessibility of the paramedical examination units was good. The degree of satisfaction was measured by a five point rating scale for series of questions. The response were "very satisfied" or "satisfied" with professional services but not medical expense and cashier attitude. According to our results, some of our attempts to innovate service have been done including an appointment system, colored directional arrowheads, and changing our schedule to opening 30 minutes earlier.

Increased plasma prolactin levels in ovariectomized thyroidectomized rats treated with estrogen

It is well established that TRH exerts a stimulatory effect on the secretion of both TSH and PRL. Clinically, hyperprolactinemia is usually present in hypothyroid women, but not men. In experimental studies, results vary because of the sexes, and treatments of animals differ. The purpose of this study was to further investigate the physiological control of PRL secretion in hypothyroid female rats. Adult female Sprague-Dawley rats that were surgically ovariectomized (OVX) and/or thyroidectomized (Tx) for 2 weeks were used. Serial blood samples were collected through indwelling intraatrial catheters, and plasma PRL and TSH levels were measured by RIA. We found that OVX + Tx and polyestradiol phosphate (PEP; 0.1 mg/rat, sc)-treated rats exhibited significantly higher basal PRL and TSH levels and afternoon surge PRL levels than sham Tx rats with the same treatments. On the other hand, if OVX + Tx rats were not treated with estrogen, their plasma PRL levels were not significantly different from those in sham Tx controls. If challenged with TRH (1 microgram/rat, iv), significantly higher PRL responses were found in OVX + Tx + PEP rats than in sham Tx rats. The contents of TRH in the median eminence of Tx rats, however, were not different from those in sham Tx rats. When challenged with domperidone (10 micrograms/rat, iv), a dopamine antagonist, no difference in PRL increments was found in the two groups of animals. Treatment with CB154, a potent dopamine agonist, did not eliminate the difference in basal PRL levels between the two groups. Pretreatment with a smaller dose of domperidone (1 microgram/rat), however, enhanced the PRL-releasing effect of TRH more in Tx than in sham Tx rats. When T4 (2 or 10 micrograms/100 g BW.day for 21 days) was replaced in Tx rats starting the second day after Tx, both basal and TRH-stimulated PRL secretion were significantly decreased in a dose-dependent manner. In conclusion, the increased PRL levels in OVX + Tx + PEP rats may be due to increased responsiveness of the anterior pituitary gland to TRH, and not to a decreased responsiveness to dopamine. In addition, the elevation of plasma PRL in OVX + Tx + PEP rats is negatively correlated with plasma levels of thyroid hormone.

Evolutionary study on the Coxsackievirus A 24 variant causing acute hemorrhagic conjunctivitis by oligonucleotide mapping analysis of RNA genome

The evolution of the variant of Coxsackievirus A 24 (CA 24 v) which causes acute hemorrhagic conjunctivitis was explored. Using 15 isolates obtained from Southeast Asia during the period 1970-1986, the genetic distance between isolates was estimated from pairwise comparison of nucleotide changes deduced from common spots on oligonucleotide maps of the isolates. From regression analysis of the genetic distance and the time of isolation of the isolates, the evolutionary rate of CA 24 v was estimated to be 3.44 x 10(-4)/nucleotide/month. The phylogenetic relationship of these isolates was explored using the neighbor-joining method and the modified unweighted pair group method using arithmetic averages (UPGMA). The phylogenetic tree constructed indicates that CA 24 v appeared from one focal place in July 1968 +/- 25 months, very close to the time of the first world epidemic of, then newly recognized, acute hemorrhagic conjunctivitis.

The melanin operon of Streptomyces antibioticus: expression and use as a marker in gram-negative bacteria

The melC operon of Streptomyces antibioticus contains two genes, melC1 and melC2, necessary for the production of melanin pigment. We transferred the coding sequence of melC1 and melC2 to Escherichia coli plasmid pMTL23 such that its transcription was under the control of the lac promoter and melC1 was translationally fused to the lacZ alpha fragment. E. coli cultures containing this plasmid, pIF413, produced melanin after overnight incubation on 2YT agar supplemented with 0.1 mM CuCl2, 0.36 mM IPTG (or 0.2% lactose), and 2 mM tyrosine. Erwina carotovora could also be transformed by pIF413 to produce melanin. Two shuttle vectors were constructed: pLUS415 for E. coli and Streptomyces, and pLAF413 for E. coli and Xanthomonas campestris. These vectors confer melanin pigmentation in all the hosts that harbor them. The melC sequence provides the vectors with a convenient cloning marker for insertional or replacement inactivation.

[Intraocular lens implantation at Kaohsiung Medical College]

Between March 1984 and December 1987, 993 cataractous eyes in 884 patients (462 males, 422 females) were operated on using intraocular lens implantation at the Kaohsiung Medical College Hospital. The age of the patients ranged from half year to 93 years, with an average of 61.9 years. Primary lens implantation was performed in 98.4% of the cases, secondary implantation in 1.6% of the cases. There were 6 cases were done by using the triple procedure (combined keratoplasty with cataract extraction and intraocular lens implantation). Among these 742 eyes followed-up for from one to 43 months, final vision could be corrected to 6/12 or better in 63.5% of the cases. While 64.4% of the cases of post-operation cylinder were less than 2 diopters, the final refraction showed that the spherical equivalent diopters were within 2 diopters in 61.7% of the cases. Complications in the anterior chamber lens group included pupillary changes (21.2%), pseudophakic bullous keratopathy or decompensation (13.5%), lens subluxation or dislocation (13.5%) and cystoid macular edema (5.8%). Complications in the posterior chamber lens group included pupillary changes (16.2%), posterior capsular thickening (3.2%), anterior or posterior synechiae (2.7%) and lens subluxation or dislocation (2.8%).

Trabeculectomy with simultaneous topical application of mitomycin-C in refractory glaucoma

From May 1981 to Feb. 1989 trabeculectomy with per-operative topical application of mitomycin C was performed on eyes with refractory glaucoma. All eyes had undergone prior one, two or more than two antiglaucoma surgeries without success for IOP control. Other risk factors in the present series of eyes included young age, aphakia, rubeosis and glaucoma secondary to trauma or associated with anterior uveitis. 59 eyes underwent trabeculectomy with mitomycin application. 14 eyes were lost. 45 eyes of 42 cases, 33 eyes of 31 males and 12 eyes of 11 females were followed for a period of 1 to 8 years, an average 3.0 +/- 1.9 years. The success for IOP control less than 21 mmHg was 77.8%, 35/45 eyes. The success rates were 92%, 11/12 eyes in females and 73%, 24/33 eyes in males. Complications reported in 5-fluorouracil studies such as corneal epithelial toxicity and delayed healing of conjunctival wound were not encountered. The histo-pathological changes of wound healing after trabeculectomy with topical mitomycin application was discussed. In the healing process success to achieve filtration is more likely by pharmacolocally interferring with earlier steps in the process. We recommend the use of per-operative topical application of mitomycin C during trabeculectomy in eyes with uncontrolled glaucoma and poor prognosis, specifically after previous cataract extraction or unsuccessful antiglaucoma surgery.

Incorporation of biological information in cancer risk assessment: example--vinyl chloride

Vinyl chloride (VC) is used as an example to demonstrate how biological information can be incorporated into quantitative risk assessment. The information included is the pharmacokinetics of VC in animals and humans and the data-generated hypothesis that VC primarily affects the initiation stage of the multistage carcinogenesis. The emphasis in this paper is on the improvement of risk assessment methodology rather than the risk assessment of VC per se. Sufficient data are available to construct physiologically-based pharmacokinetic models for both animals and humans. These models are used to calculate the metabolized dose corresponding to exposure scenarios in animals and in humans. On the basis of the data on liver angiosarcomas and carcinomas in rats, the cancer risk per unit of metabolized dose is comparable, irrespective of routes (oral or inhalation) of exposure. The tumor response from an intermittent/partial lifetime exposure is shown to be consistent with that from a lifetime exposure when VC is assumed to affect the first (initiation) stage of the multistage carcinogenic process. Furthermore, the risk estimates calculated on the basis of animal data are shown to be consistent with the human experience.

A dose-response analysis of skin cancer from inorganic arsenic in drinking water

A study of the prevalence of skin cancer among 40,421 persons consuming arsenic-contaminated drinking water in Taiwan was used for a cancer dose-response assessment of ingested arsenic. The numbers of persons at risk over three dose intervals and four exposure durations were estimated from the data in order to apply the method of maximum likelihood to a multistage-Weibull time/dose-response model. A constant exposure level since birth for each of the exposure categories was assumed. It was found that the cumulative hazard increases as a power of three in age, and is linear or quadratic (with a linear coefficient) in dose. Observations from a smaller epidemiologic survey in Mexico were similar to what would be predicted from the model of the Taiwan data. Assuming that the skin cancer risk from ingested arsenic in the American population would also be similar to the Taiwan population, an American male would have a lifetime risk of developing skin cancer of 1.3 x 10(-3) (3.0 x 10(-3] if exposed to 1 microgram/kg/day for a 76-year lifespan (median lifespan in the U.S.).

A mutation of Streptomyces lividans which prevents intraplasmid recombination has no effect on chromosomal recombination

A mutation (rec-46) of Streptomyces lividans, previously shown to prevent (or greatly diminish) homologous and illegitimate intraplasmid recombination, was shown to have no effect on generalised chromosomal recombination occurring in matings or in protoplast fusions, nor to affect homologous recombination between a recombinant plasmid and the host chromosome. By comparison with Escherichia coli mutants defective in various aspects of recombination, the rec-46 mutation is similar to those in recF, recJ, recO and topA.

[Clinico-etiological observation of 13 cases of mycobacterial keratitis]

We report a series of 13 cases of atypical mycobacterial keratitis encountered in 1986 and 1987. The ratio of mycobacterial keratitis to the total number of corneal ulcer cases increased recently from 1% in 1984 to 8% in 1988 at our clinic. The diagnosis was established by a positive acid-fast stain of smear and a Löwenstein-Jensen media culture. Of the 13 cases, 12 were diagnosed within one week after the first presentation. All cases had a history of corneal trauma; there was foreign body injury in 10 cases, pterygium surgery in 2 cases and penetrating keratoplasty in one case. The clinical pictures of mycobacterial keratitis mostly included anterior stromal infiltrate (100%), necrotic abscess (69.2%), migration lesion (69.2%) and Descemet's folding (61.5%), showing resemblances to fungal keratitis in their characteristics. Species identification showed 11 cases of Mycobacterium fortuitum and 2 cases of Mycobacterium chelonei. On the sensitivity test Rifampin (12 cases, mean 19 mm), Kanamycin (11 cases, mean 29 mm), Ethambutol (11 cases, mean 28 mm), Amikacin (11 cases, mean 19 mm), Netilmicin (9 cases, mean 20 mm) and Tobramycin (8 cases, mean 20 mm) were more effective. Ten of the 13 cases completely healed after treatment and remained quiet during the follow up period of more than one year. In the other 3 cases there was no follow up. We emphasize that the recognition of the clinical features of the corneal findings will facilitate an early diagnosis of this disease and is of essential importance for the salvage of the eye.

Photo-switchable ion and enzyme sensors. Photoinduced potentiometric response of glassy carbon electrode coated with polymer or polymer/enzyme dual membrane

Photo-switchable ion and enzyme sensors were fabricated by the use of glassy carbon electrode coated with nonactindoped or enzyme modified poly(vinyl chloride) (PVC) membranes. The ion sensor with nonactin-doped PVC membrane, which contained spirobenzopyran as the photosensitive dye, exhibited a potentiometric photoresponse to NH4+ ion in the solution. The dynamic range of the NH4+ ion sensor was 10(-7)--10(-3) M. Urea, adenosine, and asparagine sensors were prepared by coating the surface of the NH4+-ion sensor with urease, adenosine deaminase, and asparaginase membranes, respectively. These enzyme sensors could be used for determining the substrates at the micro mole level. The performance characteristics of these sensors were compared with those previously prepared membrane electrode sensors.

[Adverse side effects caused by topically applied antiviral agents in herpetic keratitis]

The present paper reviews the adverse side effects caused by topically applied antiviral agents in herpetic keratitis. The effective treatment of herpetic keratitis with IDU, a chemotherapeutic agent, was first reported in 1962. After its introduction into ophthalmic therapy for herpetic keratitis, drops of IDU were administered every hour by day combined with ointment every two hours by night. The therapy often continued for months or in some cases, even more than one year. Numerous reports on its side effects have appeared. The side effects can be classified into two categories. The first category is allergic contact blepharodermatitis, a type IV delayed hypersensitivity reaction. Its occurrence is difficult to foresee. This category I side effect rarely results in the destruction of the ocular tissues. The second category of side effects is a drug-induced toxic side effect resulting in punctate epithelial keratitis, papillary conjunctivitis or follicular hypertrophy and lacrimal punctal obstruction. After withdrawal of IDU, these ill effects usually subside soon. When IDU is further continued, the destructive change of the tissues will ensue. Conjunctival cicatrization, symblepharon, corneal neovascularization, cicatrization and irreversible punctal occlusion have been reported in cases with prolonged IDU treatment. In addition to IDU for therapy of herpetic keratitis, we are fortunate to have F3T, Ara-A and acyclovir. They show no cross sensitivity reaction nor any cross toxic reaction to each other. However, if administered more than several times daily and continued for a prolonged period of time, these antiviral agents, like IDU, can also result in reversible side effects and, further, irreversible tissue destruction. Conjunctival cicatrization and permanent punctal occlusion caused by prolonged administration of F3T have been reported. Prompt recognition of the untoward reactions and withdrawal of the antiviral agent will result in the subsidence of the toxic reaction changes and prevent the eye from irreversible destruction. The recognition, prevention and management of the untoward side effects also are discussed.

[The ocular fundus findings in dengue fever]

From September to December of 1988, 24 cases of clinical diagnosed dengue fever accompanied by visual disturbances were studied. A detailed history and a detailed ocular examination including visual acuity, slit lamp examination, fundus examination through dilated pupil and fluorescein angiography were conducted. In some cases, Amsler grid, visual field, visual evoked potential and color vision test were also evaluated. The chief complaints of these 24 patients were blurred vision, central scotoma, floaters, photophobia and halo vision. The intervals between onset of fever and awareness of blurred vision were 2 to 15 days with an average of 7.26 days. The ocular fundus changes included macular hemorrhage, retinal hemorrhage, maculopathy, Roth's spot, diffuse retinal edema, peripapillary hemorrhage vitreous cells and blurring optic disc. The fluorescein angiographic findings included poor choroidal flushing, delayed disc filling, disc extravasation, block fluorescence, capillary obliteration, non filling of macular network, capillary leakage and window defect. Seventeen cases (30 eyes) were followed-up for 2 weeks to 3 months. Visual recovery was good in most of the cases. However, 2 cases (4 eyes) showed poor visual outcome. In this series studied, the principle ocular fundus change caused by dengue fever was macular hemorrhage. This may be due to the capillary changes near the macular area. But in some of the cases, the direct viral invasion and/or indirect changes of the optic nerve, the retinal pigment epithelium or photoreceptors should be considered.

Vibrio vulnificus infection

We report 3 cases of Vibrio vulnificus infections from Taiwan. Patient 1, who manifested symptoms of primary septicemia, died after 2 days. Patient 2, who had a wound infection and signs and symptoms of sepsis but negative blood cultures, responded to tobramycin and chloramphenicol plus surgical debridement, and recovered after 26 days of hospitalization. Patient 3 had secondary septicemia originating from a wound inflicted by a shrimp. Originally, the patient seemed to respond to ceftazidime and amikacin treatment along with surgical debridement, but subsequently died from adult respiratory distress syndrome (ARDS) induced by several episodes of aspiration which occurred after initial clinical improvements. We conclude that, for patients with severe wounds and evidence of V. vulnificus infection, an appropriate, powerful antibiotic, such as one of the third generation cephalosporins should be used as initial therapy unless the nature of the infection indicates other treatment.

A trans-acting gene is required for the phenotypic expression of a tyrosinase gene in Streptomyces

The melanin locus (melC) from Streptomyces antibioticus was previously shown to be composed of two open reading frames (ORFs), melC1 and melC2. The melC2 ORF codes for the polypeptide chain of tyrosinase (apotyrosinase). The function of melC1 is not known except that insertional mutation within it abolishes the tyrosinase activity. Here, we show that in Streptomyces lividans TK64 harboring melC1 mutated and melC2 intact (melC1- melC2+) plasmids, while there was no tyrosinase activity, melC transcript was synthesized and apotyrosinase could be detected. The apotyrosinase could be activated to a limited degree by incubation with copper ions, or by mixing the mycelial extract from a culture harboring a melC1- melC2+ (pPF950) plasmid with that from a culture containing a melC1+ melC2- (pSA1) plasmid. Complementation analysis showed that melC1 acted in trans on the tyrosinase gene expression. Together, these results suggest that melC1 encodes or regulates a copper-transfer protein serving an in vivo copper-donor function in the biosynthesis of active tyrosinase.

Intraplasmid recombination in Streptomyces lividans 66

An Escherichia coli-Streptomyces shuttle plasmid pIF132 containing two direct mel repeats was constructed. While pIF132 replicated relatively stably in E. coli (Rec+ or recA), its structure was unstable in S. lividans: recombination between the mel repeats resulted in a smaller plasmid, pIF138. Furthermore, pIF132 formed oligomers extensively in E. coli but not in S. lividans.

Levels of high energy phosphates in human lung cancer cell lines by 31P nuclear magnetic resonance spectroscopy

Human lung cancers are divided into small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC) based on established criteria. SCLC differs from NSCLC by the expression of biomarkers, including creatine kinase-BB isoenzyme (EC 2.7.3.2). Subtypes of SCLC are referred to as classic and variant, both of which have elevated levels of creatine kinase-BB isoenzyme. We, therefore, applied 31P nuclear magnetic resonance spectroscopy to cell lines of classic SCLC, variant SCLC, and NSCLC human tumors, using continuous perfusion to identify any differences in the detectable levels of intracellular high-energy phosphate compounds. The spectra indicate that only the variant SCLC cells maintain high levels of phosphocreatine. Additionally, the classic SCLC cells express elevated levels of a diphosphodiester. Neither phosphocreatine nor diphosphodiesters are found in the NSCLC cell spectra.

Isolation and characterization of Streptomyces lividans mutants deficient in intraplasmid recombination

Plasmid pIF132 containing two direct repeats of the mel (melanin) sequence was used to monitor intraplasmid recombination. Five mutants of Streptomyces lividans TK64 deficient in intraplasmid recombination were isolated. Four contained additional defects in aerial mycelium formation, pigmentation, and nutrient requirements; among these two showed extensive amplification of chromosomal sequences. Mutant JT46 had no pleiotropic defects but had the most severe blockage in recombination. Only one of the mutants was slightly more sensitive to UV and two were slightly more sensitive to mitomycin C. Plasmid pWCL1 (containing pIJ702, pUC12, and HBVsAg sequences; Lee et al. 1986) could not stably replicate in TK64 without spontaneous deletions. In contrast the mutant JT46 maintained the integrity of pWCL1 much more stably.

Comparative studies on aetiology and epidemiology of viral conjunctivitis in three countries of East Asia--Japan, Taiwan and South Korea

A total number of 1105 cases with viral conjunctivitis, mainly epidemic kerato-conjunctivitis (EKC) consisting of 354 cases from Sapporo, Japan, of 628 from Kaohsiung, Taiwan and of 123 from Busan, Korea, encountered during the periods, 1980-81 and/or 1983, were studied aetiologically and epidemiologically. Patients were aged from 27 days to 88 years with a peak in the 20-29 year age group. Aetiological diagnoses were established in 610 cases (55%), consisting of 536 cases (49%) caused by adenoviruses and of 74 (7%) by EV 70. The most frequently detected agent was Ad 8 (57%), followed by EV 70 (12%), Ad 3 (9%) and Ad 19 (7%). The aetiological profiles of viral conjunctivitis were generally similar in three cities of East Asia. EKC (70%) was mainly caused by Ad 8, Ad 19 and Ad 37, but AHC (13%) by EV 70 and PCF (5%) by Ad 3 and Ad 11. Ad 19 and Ad 37 isolates in three cities were compared with the cleavage patterns with restriction endonucleases, BamHl, Smal, Sall and Hindlll. All of the Ad 19 isolates tested were identical to Ad 19a reported by Wadell et al, and all but three isolates of Ad 37 were identical to the Ad 37 prototype prevalent in Europe and the US. The three isolates of Ad 37, different from the prototype in cleavage pattern with Hindlll, designated as Ad 37A, were detected in Sapporo and Kaohsiung in 1980. From the cleavage patterns with four restriction endonucleases, Hindlll, BamHl, Sa1l and Sstl, the Ad 8 isolates in 1983 were divided into three subtypes, which were associated with the cities isolated.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural stability of heterologous genes cloned in Streptomyces plasmid pIJ702

A recombinant plasmid pWCL1 containing Streptomyces plasmid pIJ702, E. coli plasmid pUC12, and hepatitis B viral surface antigen (HBsAg) gene was stably maintained in E. coli, but exhibited structural instability in S. lividans 1326. The deletions were found ranging from 2.75 to 5.65 kilobases (kb) and most of them occurred within the melanin (mel) gene of pIJ702, resulting in the loss of part of the mel gene sequence plus the insert. The removal of the pUC12 sequence from pWCL1 eliminated the instability. However, pUC12 alone inserted in either orientation on pIJ702 also caused the deletion in S. lividans 1326. The results indicated that the structural instability of hybrid plasmid of pIJ702 depended on the interaction between the mel sequence and the inserted sequence.

Adaptive cellular response to hyperthermia: 31P-NMR studies

Dynamic intracellular ATP and Pi levels were measured non-invasively for Chinese hamster V79 cells by 31P-NMR under conditions of thermotolerance and heat-shock protein induction. High densities of cells were embedded in agarose strands, placed within a standard NMR sample tube, and perfused with medium maintained either at 37 or 43 degrees C at pH 7.35. Cell survival and heat-shock protein synthesis were assessed either from parallel monolayer cultures or cells dislodged from the agarose strands post-treatment. Thermotolerance (heat resistance) and heat-shock protein synthesis was induced by a 1 h exposure to 43 degrees C followed by incubation for 5 h at 37 degrees C. After the 5 h incubation at 37 degrees C, marked thermal resistance was observed in regard to survival with concomitant synthesis of two major heat-shock proteins at 70 and 103 kDa. Studies were also conducted where tolerance and heat-shock protein synthesis were partially inhibited by depletion of cellular glutathione (GSH) prior to and during heat treatment. Dynamic measurement of intracellular ATP of cells heated with or without GSH depletion revealed no change in steady-state levels immediately after heating or during the 5 h post-heating incubation at 37 degrees C where thermotolerance and heat-shock proteins develop. These data are consistent with other reported data for mammalian cells and indicate that the steady-state ATP levels in mammalian cells remain unchanged during and after the acquisition of the thermotolerant state.