Pulmonary Response to Perfluoropolymer Fume and Particles Generated under Various Exposure Condotions

Pulmonary Response to Perfluoropolymer Fume and Particles Generatedunder Various Exposure Conditions. LEE, K. P., AND SEIDEL W.C. (1991). Fundam Appl. Toxicol. 17, 254–269. Combustion-producttoxicity of perfluorinated polymers in small-scale tests variedmarkedly under various exposure conditions. The toxicity ofperfluoropolymer fumes is associated with submicron pyrolysispartides (0.03–0.15 µm ) in the fumes The toxicityof pyrolysis products was not observed in rats exposed to thefumes filtered to remove the particles. The particles in thefume were agglomerated by aging or a water-treatment process,and the toxicity of particles was markedly reduced when ratswere exposed to aged or water-treatd fumes. Some agglomeratedparticles showed chain-aggregation and ultimately attained nonrespirablesize. The reduced toxicity of pyrolysis fume is believed tobe due to a decreased number of toxic particles resulting fromparticle agglomeration. Aged particle agglomerate was not toxicwhen instilled intratracheally into the rats. However, the particleagglomerate became toxic when rats were exposed by the inhalationto fumes evolved from the reheated agglomerate. The fumes containednumerous toxic submicron particles evolved from thermal dacompositionof agglomerates by reheating. Rats exposed to the pyrolysisfumes died with pulmonary edema and hemorrhage due to Type Ipneymoqte damage. The edematous lungs revealed some agglomeratedparticles, but it was difficult to distinguish small pyrolysisparticles from contaminating dust or cellular debris.     

Noninvasive Estimation of End-Systolic Aortic Pressure in Children

To simplify the estimation of end-systolic aortic pressure ( P _es) noninvasively, a regression equation was derived from intra-arterial measurements. Peak-systolic ( P _ps), P _es, and diastolic aortic pressure ( P _d), pulse pressure ( P _p), heart rate, hemoglobin, body weight, and height were measured. Cardiac index and body surface area were calculated in 66 patients (17 with aortic runoff lesions, group I; 49 without lesions, group II) with various heart diseases without aortic stenosis (35 males, 31 females, mean age 4.6 years) during the course of diagnostic catheterization. Using a stepwise regression analysis, the following relationship was determined from the combined groups: P _es= 0.422* P _ps+ 0.617* P _d+ 1.377. The correlation between P _es measured directly and P _es calculated from our formula was quite strong( r = 0.957, P = 0.0001), as was the correlations between each subgroup ( r = 0.948, group I; r = 0.959, group II). The correlation between P _es calculated and that estimated using an indirect carotid pulse tracing method was also strong ( r = 0.912, P = 0.0001, n = 31). This regression equation appears applicable to infants or children with aortic runoff lesions in whom it is difficult to measure P _es by noninvasive methods using the carotid pulse. (ECHOCARDIOGRAPHY, Volume 8, September 1991)     

Proton,calcium, and magnesium binding by peptides containing γ-carboxyglutamic acid

γ-Carboxyglutamic acid (Gla) is believed to bind Ca [II] ions and Mg [II] ions in prothrombin and other coagulation proteins. Binding constants for H ⁺, Ca [II] ions, and Mg [II] ions to Gla-containing peptides are determined using pH and ion selective electrode titrations. The binding constants for peptides containing a single Gla residue are similar to the constants for malonic acid. Peptides containing two Gla residues in sequence (di-Gla peptides) bind Ca [II] ions and Mg [II] ions more strongly. K_MgL for the di-Gla peptides is similar to the site-binding constant for Ca [II] ions in denatured BF1. These di-Gla peptides may be useful analogs for metal binding by the disordered Gla domain in BF1.     

Membranous obstruction of inferior vena cava in Taiwan

Abstract Membranous obstruction of the inferior vena cava (MOVC) is a rare cause of Budd-Chiari syndrome. When compared to the West, the incidence of MOVC was reported to be higher in the Orient, India and South Africa. From 1979 to 1993, 16 consecutive Chinese patients (mean age 50 years) with MOVC were retrospectively evaluated. The diagnosis in these MOVC patients was usually delayed with a meanlag time of lll months. Most of the cases were detected by a delicate ultrasonographic examination of the abdomen. Segmental narrowing of the inferior vena cava in 11 patients was the predominant type of MOVC, while five experienced a membranous obstructive type. Only one of five surgery-treated patients had a postoperation survival > 5 years, while five out of the nine patients who received conservative treatment still survived after a 6-15 year follow up. Two patients received percutaneous angioplasty (PTA). One survived 4 years and the other expired 5 years after the PTA. Two patients (12%) developed a hepatocellular carcinoma in their disease course, and the incidence was lower than in previous reports from Japan and South Africa. The incidence of hepatitis B surface antigen in MOVC did not increase in our patients compared with the general population. In conclusion, the inferior vena cava should be carefully evaluated in an ultrasonographic examination of the abdomen to increase the diagnosis rate of MOVC. Surgical intervention should be carefully justified according to the patient's symptoms and signs, the types of obstructive lesions and the expertise of the surgeons.     

Cough mixture misuse in Hong Kong - an emerging psychiatric problem?

Cough mixture misuse has become a focus of concern in Hong Kong since the late 1980s. Psychiatric admissions related to cough mixture misuse have been reported with increasing frequency during the past 5 years. A retrospective chart review of psychiatric admissions related to cough mixture misuse for a 54-month period was conducted in two psychiatric units in Hong Kong. Twenty-seven subjects were identified. The main psychiatric presentations included acute organic brain syndrome, schizophreniform psychosis and affective episode. They appeared to be associated with the pharmacological activities of opiates, antihistamines and sympathomimetics, the main ingredients of most cough mixtures.     

Long-Term Stability of P Wave Sensing in Single Lead VDDR Pacing: Clinical Versus Subclinical Atrial Undersensing

Optimal function of a single lead P wave synchronous rate adaptive ventricular pacing system (VDDR) requires reliable P wave sensing over time and during daily activities. The stability of P wave sensing and the incidence of sensitivity reprogramming in a single pass lead with a diagonally arranged bipole was assessed in 30 patients with complete atrioventricular block over a follow-up period of 12 ± 1 months (range 6 months to 3 years). Atrial sensing was assessed during clinic visits, by physical maneuvers (postural changes, breathing, Valsalva maneuver, walking and isometric exercise), maximum treadmill exercise and Holter recordings. P wave amplitude at implantation was 1.21 ± 0.09 (0.5–3.6) mV, and the atrial sensing threshold remained stable over the entire period of follow-up. Using an atrial sensitivity based on twice the sensing threshold at 1 month, P wave undersensing was found in 2, 4, 3, and 7 patients during clinic visit, physical maneuvers, exercise, and Holter recordings, respectively. Atrial sensitivity reprogramming was performed in three patients based on the correction of undersensing during physical maneuvers. Although eight patients had atrial undersensing on Holter recordings, the number of undersensed P waves was small (total 101 beats or 0.013%± 0.001% of total ventricular beats) and no patient was symptomatic. One patient had intermittent atrial undersensing at the highest sensitivity, but the VDDR mode was still functional most of the time. No patient had myopotential interference at ihe programmed sensitivity. One patient developed chronic atrial fibrillation and was programmed to the VVIR mode. Thus, single lead VDDR pacing is a stable pacing mode in 97% of patients. Because of the large variability of P wave amplitude, the use of a sensitivity margin at least three times the atrial sensitivity threshold will maximize atrial sensing and minimize the need for atrial sensitivity reprogramming (1/30 patients). Physical maneuvers and exercise tests are effective means for rapid assess ment of the adequacy of P wave sensing.     

A single standard nocturnal dose of nizatidine enhances the healing of active duodenal ulcers among Chinese

Abstract Chinese people have a lower maximal acid output and gastrin response to meals compared to Western people. The aim of the present study was to assess the efficacy of a half-single nocturnal dose of nizatidine (150 mg at bedtime [h.s.], n = 40) with a standard full dose given once nightly (300 mg h.s., n = 38) or twice daily (150 mg twice a day [b.i.d.], n = 43) in the treatment of Chinese patients with active duodenal ulcers. An endoscopy was performed upon entry and at 4 week intervals until the ulcer healed (up to 8 weeks). There is no statistical difference in healing rates after 4 weeks of treatment (52.5, 52 and 47% in nizatidine 150 mg h.s., 150 mg b.i.d. and nizatidine 300 mg h.s., respectively) whereas nizatidine 300 h.s. had a significantly higher healing rate compared to nizatidine 150 mg h.s. and b.i.d. after 8 weeks of treatment (89 vs 70 and 67%, P < 0.05) by uni- and multivariate analysis of clinical and endoscopic characteristics. Symptomatic response was not significantly different in these three treated groups. Our study suggested that a half-single nocturnal dose of nizatidine is not ideal for the treatment of duodenal ulcer in Chinese patients, whereas a single standard nocturnal dose appears more effective than a twice-daily regimen.     

独角莲化学成分的研究

从天南星科植物独角莲块茎中分得三种成分:(1)β一谷甾醇,C₂9H₅₀O,熔点137—138℃,[α]_D²³=-36.4°(CHCl3).(2)β-谷甾醇-D-葡萄糖甙,C₃₅H₆₀O₆,熔点277—279℃(分解),[α]_D²²=-44.5°(吡啶).(3)不活性肌醇,C₆H₁₂O₆,熔点223—225℃. 尚未肯定部分有:(1)酸性部分:由醚浸出液经碳酸氢钠提得部分,进行纸上层析,溶剂系梳为正丁醇:5M甲酸水溶液(90:55),在紫外线下有二个蓝色萤光点.R_f1值=0.78,R_f2值=0.90.如以正戊醇:5M甲酸水溶液作溶剂,则R(f1)值=0.73,R_f2)值=0.90.(2)溶血成分:由醇浸出液经铅盐法处理,由盐基性沉淀部分,分得具溶血及吸湿性的淡棕色粉末,未能测得熔点,可能为皂甙。     

氯丙嗪及利血平对几种药物催吐作用的影响

常山(Dichroa febrifuga Lour.)属虎耳草科(Saxifragaceae),药用其根,是中医治疟之要药。近代学者从常山根提出六种生物碱即常山碱甲、乙、丙(α-,β-,γ-dichroines),dichroidine,4-quinazolone及一易潮解的生物碱。有抗疟作用的成分是常山碱甲、乙及丙,以丙碱的抗疟效力最强,毒性亦最大;乙碱次之;甲碱毒性最小,抗疟效果虽也最小,但仍与奎宁相似。常山碱能引起严重的副作用,如噁心呕吐,以致不能用于临床。同样,最近     

Gastritis Varioliformis

A patient with chronic erosive gastritis and protein-losing gastropathy is reported. Presentation was with weight loss and abdominal discomfort. There were endoscopic and radiological features of erosive gastritis. Radioactive chromium studies confirmed that the low serum albumin was associated with fecal protein loss. No improvement occurred with bed rest or Caved S but coincided with DeNol therapy.