The proposed death certificate for South Africa. Part II. Feasibility study.

The proposed new death certificate was tested in urban and rural hospitals and among general practitioners. Of the 471 death certificates returned, 70% were correctly completed. The underlying cause of death was identifiable in 86.6% of cases. The accuracy of cause of death statements was analysed in greater detail. Some items on the proposed form were not clear and needed improvement, i.e. instructions to mark an applicable answer and refer to instructions on the reverse page. The participants completed a questionnaire to assess and comment on the new form. A refined version thereof was prepared as a result of this study.


Peri-operative mortality in the anaesthetic service at Tygerberg Hospital.

This study reports on the process of peer review of peri-operative mortality at Tygerberg Hospital. The peri-operative mortality rate for the past 3.5 years was 11.9/10,000. The departmental evaluation committee thought that 3.4/10,000 of these deaths were anaesthetic-related. In 2.3/10,000, the anaesthetic contributed to the death of the patient and in 10 cases (total case load = 94,945; i.e. 1.1/10,000) anaesthesia was responsible for the death of the patient. The majority of the peri-operative deaths (8.5/10,000) were caused by a combination of trauma and haemorrhagic shock.


Comparative assessment of phase contrast microscopy and Coulter counter measurements in localising the site of haematuria.

Haematuria is a common diagnostic problem in clinical practice and is seen in a large number of renal, urological and systemic disorders. The routine use of dipstick methods has increased the frequency of detection of microscopic haematuria. It is desirable to develop a simple, non-invasive, easily reproducible, quantitative technique that would help to determine the site of bleeding and thereby direct the patient either to the nephrologist or to the urologist. This study compares the accuracy of phase contrast microscopy with Coulter counter measurement of red cell distribution volumes as a means of distinguishing glomerular haematuria from non-glomerular haematuria. Of 20 patients with biopsy-proven glomerulonephritis, 13 (65%) were correctly identified by phase contrast microscopy and 19 (95%) by the Coulter counter method. In 18 patients with pathological conditions affecting the lower urinary tract phase contrast microscopy was correct in 6 (33%) and Coulter counter measurement in 17 (94%). Coulter counter measurement is the simpler and more accurate method of screening for the source of haematuria, but is inaccurate when the red cell count in the urine is less than 0.02 x 10(12).


No osteoporosis detected by quantitative computed tomography in postmenopausal black females.

Problems associated with postmenopausal osteoporosis are believed to be almost non-existent in black South African females, but published data on their bone mineral density are lacking. In this study, vertebral quantitative computed tomography was performed on 30 postmenopausal black women with no complaints other than those attributable to oestrogen deficiency. The mineral bone density was plotted against those 'normals' of similar age provided by the Somaton DR H (Siemens) data base. In all instances the vertebral bone mineral density obtained was higher in the study group.


The pattern of poisoning from traditional medicines in urban Zimbabwe.

A 10-year (1980-1989 inclusive) retrospective study was carried out at Zimbabwe's six main urban hospitals to evaluate the epidemiology of poisoning caused by traditional medicines. A total of 1456 cases were recorded, and this represented 23% (the biggest single group) of all poisoning cases. Sixty-seven per cent (982) of the patients were male and 33% (474) were female. The majority of patients (53%; 776) were under 5 years of age; 18% (264) were 21-30 years old; the 31-40-year age group accounted for 9.1% (132) of patients, and the 11-20-year age group for 6.7% (97). A mere 1.5% (22) of patients were over 60. Sixty-one per cent (892) of all cases were of poisoning associated with medication (treatment) and 8% (113) were accidental poisonings, while suicides and parasuicides accounted for 0.2% (3) and 2% (30) respectively. The mortality rate was 6% (2% of deaths were accidental and/or treatment-related). The main reasons for seeking treatment with traditional medicines were for depressed fontanelles and fever in children and diarrhoea and abdominal pain in adults. Treatment consisted mainly of supportive therapy and involved the induction of vomiting with ipecacuanha in children. This study indicates that the use of traditional medicines is common in Zimbabwe.


Thoracoscopic wedge resection.

Thoracoscopic surgery is decidedly expanded by the ability to perform pulmonary wedge resections of the lung by using the Endo-GIA-stapler. In addition to thoracoscopic biopsies, since July 1991 we have carried out wedge resections in 12 patients suffering from spontaneous pneumothorax (nine) or peripheral bronchial carcinoma (three). Postoperatively one air fistula persisted over 9 days. The chest tube was removed within 48 h in all other patients. There was no other major complication. The postoperative hospitalization period lasted 4.6 days (1-9 days). Operating time was 44 min (30-70 min). The benefit for the patient consists in the little-impaired breathing mechanics, the short hospital stay, and the favorable cosmetic result.


Minitracheotomy: a new interventional technique for treatment of sputum retention.

Sputum retention causing pulmonary atelectasis, secondary pneumonia, and respiratory failure is a frequent complication particularly in patients recovering from abdominal and thoracic surgery. Physiotherapy and conventional therapeutic means like blind tracheobronchial and bronchoscopic suction applied to prevent and treat postoperative respiratory complications have been shown to not be completely effective. Minitracheotomy is a new alternative method for the treatment of sputum retention. Endobronchial suction can be performed as often as required, using a thin uncuffed tube (ID 4.5 mm) which is inserted into the trachea through the cricothyroid membrane under local anaesthesia. Since respiration occurs normally through the nose, mouth, and larynx these patients retain speech and the ability to cough. Complications are rare. Endobronchial suction via minitracheotomy is minimally invasive, more comfortable, and at least as effective as conventional bronchoscopic suction. It therefore has become a routine method used in the treatment of postoperative sputum retention in high-risk patients in many intensive-care units.


In-vivo measurements of early and late effects in normal tissue after abdominal X-irradiation--development of a clinically orientated score for the determination of side-effects and the individual radiation response in a mouse model.

Heiligenberger mice received abdominal single X-ray doses of either 10 or 12 Gy. Early (up to one month) and late effects (two to eight months) were measured in vivo with ten parameters (nitrite, albumin, glucose, urobilinogen, bilirubin, haemoglobine, ketone, pH, weight development, general clinical conditions). These parameters permit the assessment of the condition of the essential organ systems. Thus, their use as screening parameters appears meaningful. By creating indices and integrating these in the animal index (range 1 to 3) it is possible to obtain an impression of the health condition of the individual animal. Early and late damage can be determined with certainty despite large individual variances. Radiation-induced chronic but not lethal changes can be measured. A large early damage is also predictive for a large late morbidity; not the individual parameters allow conclusions to be drawn but instead only the total number of the parameters used here are capable of this. The results have tended to show that the systematic listing of early responses also allows for very early indication of late morbidity or chronification events to be expected. The results have shown that the individual analysis of single parameters can give rise to important indications for a decisive diagnosis. This corresponds to the usual clinical procedure and can be applied to animal experiments without restriction.


Vascular patterns of tumors: scanning and transmission electron microscopic studies on human xenografts.

The tumor vascular system plays a significant role both in tumor growth and metastasis as well as in therapy. However, there are comparatively few papers dealing with the morphology and architecture of tumor vascularity. This is inconceivable insofar as structural and architectural parameters determine tumor blood flow. Therefore, the vascular system of eight human tumor lines transplanted onto 121 thymus-aplastic nude mice was studied with light, scanning and transmission electron microscopy as well as microvascular corrosion casting. All tumors show a connective tissue-like capsule with a dense plexus of vessels forming a "vascular envelope". Particularly in early stages, these vessels follow a tortuous course with glomeruloidal arrangement and numerous indications of angiogenic activity. In the tumor centre regular arteries and veins are never to be seen. Instead, all vessels show a capillary wall construction with variations in height and electron densities of the endothelial cells. Changes in vessel diameter, lack of vascular hierarchy, blind ends as well as irregular sinusoidal systems originating from and draining to veins are common features. The vascular densities vary considerably within single tumors. Based on the vascular architecture and wall construction, necroses may occur even in areas with intervascular distances of only 15 microns. No significant differences in vascular architecture of the various cell lines could be observed.


Chest drain penetration into the transposed stomach after Ivor-Lewis esophagectomy: diagnosis by early postoperative endoscopy.

A case of chest drain tip penetration into the gastric lumen 3 days after esophagectomy is reported. Early diagnosis by endoscopy in the immediate postoperative period facilitated our management.


Changing racial composition of metropolitan areas.

In the past decade, the number of Hispanics and Asians or Pacific Islanders residing in the largest metropolitan areas increased by a remarkable 60 percent and 127 percent, respectively. In April 1990, there were 4.9 million persons of Asian or Pacific Islander origin and 14.1 million of Hispanic background living in the 25 most populous urban centers; they constituted roughly two-thirds of the nation's total population of these ethnic groups. For the most part, the destinations of these newcomers were primarily the big metropolitan areas of the West and Southwest regions of the country, although the urban centers of the Northeast and North Central attracted large numbers. By contrast, in this period the number of blacks--the largest minority group--rose by only one-seventh.


AIDS: a comparison of knowledge and attitudes among black, Hispanic and white Americans, 1990.

Increasing awareness about AIDS is an important step toward the prevention of this disease. The AIDS Knowledge and Attitudes Survey of the National Health Interview Survey shows that more than 80 percent of U.S. adults are familiar with the major modes of AIDS transmission. Despite this, up to one-third still believe that AIDS can be spread by various forms of casual contact. In the three racial/ethnic groups studied, the less educated were less knowledgeable. Further, black and Hispanic adults lagged somewhat behind white adults in certain important aspects of AIDS knowledge. About one-fourth of white, black and Hispanic adults have had the HIV antibody test. While reasons for testing differed, most of the adults were tested in health care sites. Educational counseling that should accompany HIV testing is provided to less than half of those tested. Identifying gaps in knowledge can help to more effectively target AIDS educational efforts.


Follow-up data of our pilot study on concomitant hyperfractionated radiotherapy and cisplatinum (CDDP) in patients with advanced cancer of the head and neck.

Since 1988, 52 patients with stage III/IV squamous cell cancer of the head and neck have been treated by concomitant irradiation with 2 x 1.2 Gy/d on five days per week up to a total dose between 72 and 76.8 Gy without split and 5 x 20 mg/m2 cisplatinum (CDDP) as short infusion finished approximately 30 min before the second session on five days of the first and the fifth week of radiotherapy. Radiotherapy has been suspended after 30 and 50 Gy in three patients for insufficient response. In all other patients, radiotherapy has been completed. Due to a slow haematologic recovery, 34% of the patients received only one cycle of CDDP Grade 3 mucositis, occurring during radiotherapy in all patients, healed in a couple of weeks after radiotherapy. Three patients have a persisting ulcer between eight and 36 months after radiotherapy with biopsies negative for tumour and also no other signs of tumour. The ulcers are situated in the region of the former primary tumour with an extensive destruction of tissue already before radiotherapy (cumulative risk of this complication after three years 8%). There were no other major complication. Cumulative local control after three years was 67% (75% including salvage surgery in two patients) with a plateau after twelve months. Total survival after three years was 62%. For the whole follow-up period, local control in the region of the primary tumour after radiotherapy was: 19/29 (T4), 10/15 (T3), 7/10 (T1 + 2, including salvage surgery: 8/10). Local control in the region of the nodal metastasis after radiotherapy was: 5/14 (N3, including salvage surgery: 6/14). 18/21 (N2) and 6/8 (N1).


Selected demographic and health characteristics--state variations, 1988-1991.

There is considerable regional variation in the distribution of persons over age 65, living on Social Security, living below the poverty level and with no health insurance. For the most part, such differences are reflected in low per capita income, low health care spending as well as less favorable health outcomes and health system utilization. These differences and disparities underscore the importance of considering a wide range of variables when drawing conclusions about the nation's health care system and when making policy decisions on various social programs.


Use of survey data in a corporatewide health promotion program: The MetLife experience.

MetLife developed a corporate-wide health promotion program based on a survey of its employees, its local management, and its medical personnel. The survey's goals were to determine the wellness topics of greatest interest to employees, as well as topics believed by local management and medical personnel to be of greatest need. There was surprising unanimity concerning what employees said they wanted and what managers and medical personnel believed were needed. Stress management--including relaxation techniques and time management skills--was high on all three surveys, as were the basic of nutrition, exercise, healthy aging, cancer, and men's and women's health issues.


Rapid bedside method to assess changes in postoperative fluid status with bioelectrical impedance analysis.

Estimates of daily postoperative fluid balance usually rely on properly recorded inputs, outputs, and daily weights or clinical signs. These may be imprecise (when poorly done) and are often considered tedious to perform. We used bioelectric impedance analysis (BIA) to assess changes in body water shifts in cardiac patients after surgery. Nine consecutively admitted patients undergoing coronary artery bypass (seven men and two women; age range, 43 to 67 years) were studied. Body weight, fluid intake and output, and BIA variables (resistance and reactance) were measured daily. Relationships between body weight and changes in resistance and reactance and net change in fluid balance (in liters per day) were evaluated statistically by regression analysis. Mean body weights changed significantly, reflecting early operative fluid accumulation and later postoperative diuresis; net fluid balance correlated poorly (r = 0.48; p less than 0.05) with body weight, whereas both resistance (r = -0.82; p less than 0.001) and reactance (r = -0.92; p less than 0.0001) correlated highly with net fluid balance. BIA is useful as an accurate, rapid bedside method for assessing changes in hydration status sequentially after surgery in cardiac patients with complicated fluid shifts.


Hypercaloric glycerol in injured patients.

This study investigates the effects of glycerol as a fuel source in the hypermetabolic patient (after injury). Twenty-two patients were studied after multiple trauma and randomly assigned to either glucose or glycerol as the carbohydrate source (220 gm glycerol or 320 gm dextrose) during a lipid-based system of parenteral nutrition. In the immediate postoperative period, measurements were made of nitrogen balance, substrates, energy expenditure, insulin, glucagon, and liver function tests. In the glycerol group glucose concentrations in plasma were significantly lower, whereas glycerol levels increased nearly twentyfold. Insulin and glucagon levels increased in both groups; however, the rise in insulin level was greater in the glucose group, whereas glucagon increased in both groups to a similar degree. Nitrogen balance was restored to equilibrium in the glycerol group while remaining negative in the glucose group. No abnormalities in liver function test results or differences in serum albumin levels were noted in either group. A 12% thermic effect was noted in the glucose group but not in the glycerol group. Glycerol seems to be a viable fuel source in the traumatized patient, being associated with nitrogen retention and minimal thermal effect. A marked rise in plasma levels of glycerol does occur, but this does not appear to have any associated toxicity.


Split-liver orthotopic liver transplantation: how to divide the portal pedicle.

It is possible to obtain two good-quality hepatic transplants from a single cadaveric liver by separation of right and left lobes of the liver or section between the left medial segment and the left lateral segment medial to the umbilical cleft. We attempt to define the ideal basis of separation of the structures of the portal pedicle, based on anatomic study of 25 livers. Ideally, the following should be sectioned: the left portal vein, longer and more constant than the right; the right branch of the hepatic artery, larger and more constant than the left; and the left hepatic duct, being aware of the vascularization of the common hepatic duct. Use of the left portal vein necessitates the interruption of all left venous portal branches of segment I, which should be systematically resected. A section between the left medial segment and the left lateral segment interrupts all portal venous branches of the left medial segment, which should then be resected. Before hepatic division, a cholangiogram and arteriogram are indispensable to detect variations and avoid an extensive dissection that may endanger bile duct vascularity.


Etiology and management of respiratory complications after repair of esophageal atresia with tracheoesophageal fistula.

This article reviews the cause and management of respiratory symptoms after repair of esophageal atresia with tracheoesophageal fistula (TEF). Postoperative respiratory symptoms developed in 31 (46%) of 68 patients and included apnea and bradycardia, respiratory arrest, aspiration, and recurrent pneumonia. The respiratory symptoms were initially attributed to gastroesophageal reflux (GER) in 20 patients (64%), tracheomalacia in 4 patients (13%), recurrent TEF in 4 patients (13%), and anastomotic stricture in 3 patients (10%). Three patients with GER and the three patients with a stricture were initially managed nonoperatively. The remaining 25 patients underwent surgical correction of the underlying cause of the respiratory symptoms. Despite aggressive management of this problem, 14 (45%) of these 31 patients had persistent or recurrent respiratory symptoms. Although GER is the most common cause of respiratory complications in patients who have undergone prior TEF repair, other factors are often responsible for these symptoms and should not be overlooked.


Late swallowing and aspiration problems after esophagectomy for cancer: malignant infiltration of the recurrent laryngeal nerves and its management.

One hundred eleven patients who underwent esophagectomy for squamous carcinoma of the esophagus were followed up during a 42-month period. Forty-three patients who had normal swallowing in the postoperative period had recurrent dysphagia on follow-up. The causes were benign anastomotic stricture (n = 15), malignant anastomotic recurrence (n = 2), recurrent laryngeal nerve palsy (n = 22), and no known cause (n = 4). Twenty-six patients were assessed by laryngoscopy and 15 were deemed suitable for Teflon injection of the vocal cord. All but one patient had improved swallowing and phonation after the procedure. Mean survival time after Teflon injection was 5 1/2 months. A significant proportion of swallowing problems after esophagectomy are not caused by mechanical obstruction. Teflon injection of a unilateral paralyzed vocal cord provides good palliation in these patients.


A prospective study of the value of core needle biopsy and fine needle aspiration in the diagnosis of soft tissue masses.

We prospectively sampled 38 large soft tissue masses in 37 patients with both core needle biopsy (CNBX) and fine-needle aspiration (FNA) to determine the diagnostic utility of these biopsy methods. In 27 cases the histologic diagnosis made from the resected specimen was compared with the diagnosis based on the biopsy. CNBX correctly identified 16 of 16 malignant sarcomas and 10 of 11 benign masses (one was indeterminate). The grade of the sarcoma was determined correctly in every case. There were no false malignant or false benign CNBX diagnoses. FNA correctly classified 12 of 14 malignant sarcomas and four of 11 benign lesions. Diagnoses based on FNA were limited by a high proportion of samples, especially from benign lesions, that were inadequate for definitive diagnosis and by an inability to grade many malignant sarcomas. There were no significant complications resulting from the biopsies. We conclude that CNBX is a highly accurate, easily performed method for the diagnosis of large soft tissue masses that can be accomplished with minimal morbidity.


Photoplethysmography reexamined: lack of correlation with duplex scanning.

In a prospective study a comparison was made between the results of photoplethysmography and ultrasonic duplex scanning in 151 consecutive legs with swelling, aching, and suspected venous insufficiency. Thirty-four percent of the legs had a history of previous deep venous thrombosis, 26% had undergone previous superficial vein surgery, and 11% had active or healed ulceration. Photoplethysmographic findings were normal in 86 (57%) of these legs and indicated deep venous disease in 33 (22%). With duplex scanning, incompetent vein segments were found in 140 legs (93%). The kappa coefficient of agreement between the result, classified as either normal, superficial disease only, or deep incompetence, was 0.12 +/- 0.06. In legs with superficial disease, the number of incompetent levels was no greater in legs with abnormal results of photoplethysmography than in legs with normal results of photoplethysmography. In general, an abnormal photoplethysmographic result is related to multilevel reflux and the presence of visible skin changes. Photoplethysmography had the same value, in these patients, to predict the presence of multilevel reflux as had inspection of the skin of the goiter area. These results do not warrant the continued use of photoplethysmography for surgical decision making in patients with suspected venous insufficiency.


The effect of various sympathomimetics on the regional circulations in hyperdynamic sepsis.

Because sepsis is characterized by a depression in vascular reactivity, we hypothesized that changes in organ blood flows (Q) would differ between the nonseptic and septic state during the infusion of sympathomimetics. Therefore we examined the (sepsis x organ Q) interaction during the infusion of five sympathomimetics in 36 mature, awake sheep before and after cecal ligation and perforation produced hyperdynamic sepsis. A 3-hour infusion of dobutamine, norepinephrine, dopamine, dopexamine, or salbutamol was compared with that of placebo during both nonseptic and septic studies; drug infusion was titrated to an increase in cardiac index of greater than 20%. Increased plateau infusion doses of norepinephrine (+305%), salbutamol (+275%), dopamine (+70%), and dobutamine (+49%) were required to achieve predefined treatment guidelines during the septic versus nonseptic study. Few differences in the regional effects of individual sympathomimetics were found in the nonseptic study, although infusion of sympathomimetics was accompanied by a redistribution of systemic Q toward the heart and away from the brain, kidney, small intestine, liver, and pancreas. In the septic study, however, the sympathomimetic infusions were not accompanied by the redistribution of Q away from small intestine and liver that was demonstrated in the nonseptic study. Therefore (1) the depressed vascular reactivity in hyperdynamic sepsis altered the dose profile of exogenous sympathomimetics required to augment systemic Q, and (2) the (sepsis x sympathomimetic) interaction was characterized by a depression in the anticipated redistribution of organ Q from "nonvital" to "vital" circulations.


Functional analysis of monocyte activity through synthesis patterns of proinflammatory cytokines and neopterin in patients in surgical intensive care.

This study was designed to further differentiate monocyte behavior in critically ill patients with operative or accidental trauma. The patient population studied consisted of 39 patients (17 patients undergoing elective surgery [ES], seven patients with major multiple injuries [MI], and 15 patients in an acute septic state [S]). Immunologic parameters assessed included monocyte phenotyping with the monoclonal antibody LeuM3, measurement of the cytokines interleukin (IL)-1, IL-6, and IL-8 in lipopolysaccharide-stimulated in vitro cultures of mononuclear leukocytes (PBMCs), and determination of neopterin in gamma-interferon-stimulated in vitro cultures and corresponding serum samples. Serum neopterin levels were very high in S patients (89.0 nmol/L; p less than 0.05) compared with control values (4.6 nmol/L), with a rise to 16.4 nmol/L in ES patients on day 7 and 13.4 nmol/L in MI patients on day 7. The concentrations of gamma-interferon-induced neopterin in the supernatants of the PBMC cultures were elevated in all patient groups. Severe impairment of IL-1 synthesis was seen in MI and S patients. IL-8 synthesis (818 +/- 150 units/ml, control value) was also suppressed (p less than 0.05) in MI patients; the values were 135 +/- 65 units/ml on day 1,231 +/- 110 units/ml on day 3,347 +/- 131 units/ml on day 7, and 355 +/- 107 units/ml in S patients. The kinetic patterns of synthesis were comparable for IL-1 and IL-8 in all patient groups. Lipopolysaccharide-induced IL-6 synthesis (9.4 +/- 1.5 x 10(3) units/ml, control value) was significantly elevated in the PBMC cultures of all patient groups, with the exception of the early phase after accidental trauma. Maximum amounts of IL-6 synthesis after surgery were 19.6 +/- 7 x 10(3) units/ml in S patients and 19.0 +/- 2.2 x 10(3) units/ml in ES patients. These results demonstrate (1) the impairment of the functional capacity of circulating monocytes and (2) that the degree of functional impairment is proportional to the severity of the injury.


Correction of steal syndrome secondary to hemodialysis access fistulas: a simplified quantitative technique.

Correction of symptomatic vascular steal distal to an arteriovenous fistula requires either fistula ligation or banding. Ligation carries the obvious disadvantage of destruction of a functioning angioaccess, whereas banding procedures have been plagued by the complexity of many of the reported techniques and by the difficulty of balancing fistula flow with distal perfusion. In this study a simple plication technique is described that avoids the introduction of any additional foreign material and that quantifies distal perfusion by means of intraoperative pulse volume recordings. Five patients have been treated by this method, two with autologous vein fistulas and three with bridge fistulas using polytetrafluorethylene. All five have had resolution of their ischemic symptoms with an increase in intraoperative pulse volume recordings of 5 mm or more. Only three of the patients had restoration of the radial pulse, which was not a specific end point of the banding procedure. Furthermore, all fistulas remained patent for at least 6 months and continued to provide adequate flows for hemodialysis. Banding/plication is clearly preferable to fistula closure for the management of steal syndrome. The method described herein is simple and hemodynamically identifies the minimal constriction that will resolve symptoms and preserve fistula flow.


Fetus in fetu removal in a 47-year-old man.

A case of removal of a fetus in fetu in a 47-year-old man is reported. The patient had an upper abdominal mass since birth that had never caused any subjective symptoms. A preoperative computed tomographic scan was useful to confirm the diagnosis. The operative specimen consisted of a cystic mass about 20 cm in diameter, situated in the upper retroperitoneal space. The cyst was full of a yellowish fluid and hairs. A bony structure, about 10 cm in diameter, contained a vertebral axis connected to the ribs and was adherent to the cystic wall. To our knowledge this is the first reported case of fetus in fetu described in an adult man. The tumor, present for 47 years, did not grow or cause any complications and did not show any sign of malignancy.


An embolizing lesion in a minimally diseased aorta.

A case report of a patient with an unusual source of emboli resulting in acute limb-threatening ischemia is presented. Diagnostic angiography of the lower extremity was performed, followed by thromboembolectomy, which successfully restored normal arterial flow to the threatened leg. After surgery the patient underwent transesophageal echocardiography, which failed to identify an embolic source. Because of the high degree of clinical suspicion that the primary disease process was embolic rather than thrombotic, a thorough evaluation of the arterial tree was performed, including computed tomography and aortography. A large, mobile intravascular lesion arising from a normal descending thoracic aorta was identified and successfully treated with resection and graft placement.


[Diagnosis and treatment of paroxysmal tachycardia].

The practising physician's knowledge of paroxysmal attacks of tachycardia is frequently disappointing. In this article a description is given of mechanisms and possible sites of origin of tachycardia. This is followed by a discussion on the typical history and the findings in these patients. Lastly, therapeutic guidelines are given. A discussion of the electrocardiographic features of the different types of paroxysmal tachycardias falls outside the scope of this article.


[Diagnosis of cardiac arrhythmias in general practice].

Cardiac arrhythmias represent a common diagnostic and a frequent therapeutic problem (table 1). They occur both in cordially sound people and in patients with a basic cardiac disease, their clinical significance reaching, therefore, from harmless to life-threatening episodes. For this reason, a documentation and characterization of the different arrhythmias is necessary in clinical practice in order to be able to initiate an adequate therapy in symptomatic and particularly in prognostically relevant cardiac arrhythmias.


[Drugs in atrial fibrillation].

The initial therapy of atrial fibrillation is guided by the clinical symptomatology of the patient. Acute atrial fibrillation at a rapid ventricular rate is an emergency situation. Pharmacological therapy is aimed to delay atrioventricular conduction and thereby slow the ventricular rate. A new and interesting therapeutical option to induce conversion to sinus rhythm is the intravenous administration of class-Ic drugs. The conversion rate of patients with nonvalvular atrial fibrillation of recent onset is high and accounts up to 90%. Patients with atrial fibrillation have an increased incidence of ischemic stroke. Anticoagulation, i.e. administration of aspirin in patients under 70 years of age, can reduce the occurrence of cerebral ischemic event.


[Drug therapy of atrioventricular tachycardia].

All types of antiarrhythmic drugs are suitable for the treatment of junctional and AV-reentry Tachycardias. Betablocker, calcium antagonist and digitalis are mainly influencing the conductivity in the AV node, leaving other structures unaltered. In contrast, class-antiarrhythmic drugs slow conduction and prolong the refractor effect in the accessory pathway. In addition, drugs of subclass 1c can influence especially the 'fast' pathway in dual AV-node conduction. Class-3 drugs prolong refractoring in all compartments of the heart by preventing re-entry in both, AV nodal tachycardias and AV re-entry in the WPW syndrome. The clinical indication for one of these drugs is mainly influenced by the potential side-effects and by pharmacokinetic considerations.


[Drug prevention and therapy of ventricular tachycardia].

Antiarrhythmic drugs of type I to IV (Vaughan Williams) are generally used for the treatment of ventricular tachycardia, especially in patients with symptomatic and hemodynamically not tolerated arrhythmias; however, randomized controlled studies revealed a beneficial effect on sudden cardiac death only for type-II (beta-blocking agents) and type-III (Amiodarone) antiarrhythmic drugs. These drugs are, therefore, the antiarrhythmic agents of first choice; but, in addition, underlying heart disease, triggering factors and heart-rate dependency should be considered.


[Ventricular late potentials--methods and clinical importance].

Ventricular late potentials are due to regionally depressed inhomogenous conduction, mainly in the border zone of a previous myocardial infarction. They can be recorded noninvasively using high-resolution signal-averaging techniques. They are almost never detectable in normals, whereas they represent a frequent finding in postmyocardial infarction patients. The presence of ventricular late potentials after previous myocardial infarction predicts the subsequent occurrence of hemodynamically severe sustained ventricular tachycardia and/or sudden cardiac death. Their predictive significance can be increased by combining signal-averaging with long-term ECG recording and estimates of left-ventricular ejection fraction. However, despite recent major improvements in identification of patients at risk, there is still a need for an effective mode of prevention of serious ventricular tachyarrhythmias after myocardial infarction.


[Who should be referred for electrophysiologic studies?].

Prerequisite of a rational antiarrhythmic therapy is the correct diagnosis of the given cardiac rhythm disorder. The majority of intermittent and latent cardiac arrhythmias can be reliably induced and analyzed during the electrophysiologic study (EPS). In case of bradyarrhythmias, the method is indicated in patients with suspected sinus node disease or high-grade AV conduction disturbances, as far as the cause of clinical symptoms cannot be settled by Holter recordings. Since patients with paroxysmal supraventricular tachycardias (WPW syndrome and AV nodal reentrant tachycardia) can be cured by transvenous ablation techniques, EPS is indicating in this setting in all symptomatic patients for the diagnosis and the treatment of the given arrhythmia. In patients with recurrent ventricular tachyarrhythmias, EPS should be performed to establish the diagnosis and to control medical treatment; in addition, EPS is a prerequisite for nonpharmacologic treatment modalities such as defibrillator therapy and transvenous or surgical ablation techniques. In survivors of cardiac arrest without new Q-wave myocardial infarction, persistent ventricular tachyarrhythmias can be induced in some 50% of the patients. Patients should be evaluated by EPS in case the reasons for significant clinical symptoms cannot be determined otherwise, given the likelihood, that brady- or tachyarrhythmias are the cause of the clinical symptoms; this includes patients with organic heart disease and with unexplained syncopes.


[Surgery of tachycardic cardiac arrhythmias. Surgical treatment of life threatening tachycardias: indications, surgical possibilities, results].

Electrophysiologic operations for surgical treatment of malignant tachyarrhythmias include a preoperative electrophysiologic study (EPS) to assess the characteristics and dignity of the arrhythmia, intraoperative electrophysiologic mapping to identify and localize the arrhythmogenic morphologic substrate, surgical ablation of the arrhythmogenic tissues, and early postoperative EPS to evaluate the result of the operation and the post-surgical prognosis. The majority of patients undergoing an electrophysiologic operation suffer from supraventricular tachyarrhythmias due to accessory atrioventricular bypass tracts (Wolff-Parkinson-White syndrome) and malignant ventricular tachycardias in the setting of coronary artery disease. In comparison of the natural (non-surgical) history of those rhythm problems their prognosis as regards mortality and morbidity is significantly improved by operation. Possibly the spectrum and the role of electrophysiologic antiarrhythmic surgery will be changed during the next decade by the increasing application of interventional cardiologic measures as catheter ablation (PTCA) thrombolysis.


[Clinical assessment and indications for automatic defibrillation].

A variety of therapeutic options including pharmacological treatment, surgical procedures, ablation interventions and electrotherapy are available for the management of patients who are subject to symptomatic ventricular tachyarrhythmias. Patients with documented sustained ventricular tachycardia or ventricular fibrillation are usually controlled by serial electrophysiological studies. About 30 to 60% of these patients respond to antiarrhythmic drugs during serial electrophysiological testing. Patients with severe left-ventricular function respond less frequently than those of well-preserved function. Long-term follow-up studies have demonstrated that, if ventricular tachyarrhythmias can no longer be induced on antiarrhythmic drugs or if inducibility is at least rendered more difficult, the rate of recurrences is low. In contrast, patients with still inducible ventricular tachyarrhythmias may have a poor prognosis and may suffer from frequent recurrences or may even die suddenly. Thus, nonpharmacological strategies such as an implantable cardioverter/defibrillator, transvenous catheter ablation and map-guided antitachycardia surgery have become important alternatives for drug refractory patients. Since the introduction of the implantable cardioverter/defibrillator using a nonthoracotomy approach, the intraoperative and perioperative mortality and morbidity has been significantly reduced. A widespread use of these newer devices required the establishment of guidelines for the appropriate application of this new treatment modality. Surgical, medical and economic considerations make it imperative that defibrillator therapy should be chosen on a basis of careful patient selection. The presenting clinical arrhythmia and its hemodynamic stability, underlying heart disease and left-ventricular ejection fraction should be taken into consideration.(ABSTRACT TRUNCATED AT 250 WORDS)


Microscopic and macroscopic measurements of emphysema: relation to carbon monoxide gas transfer.

Studies of the relation between the severity of structural change in emphysema and physiological abnormality have been based on macroscopic assessments, which have not been truly quantitative or sensitive enough to detect early changes. With a highly reproducible method for measuring emphysema using histological sections and a semiautomatic image analysis system, this quantitative assessment of emphysema was compared with a semiquantitative macroscopic assessment of emphysema and measurements of carbon monoxide gas transfer. Microscopic and macroscopic measurements of emphysema on 44 thoracotomy specimens were compared; only two were from non-smokers. Airspace wall surface area per unit volume was measured microscopically with an automatic image analyser and expressed as both the mean airspace wall surface area per unit volume and the mean value of the five fields with the lowest values. Macroscopic emphysema was measured directly on a tracing of the midsagittal slice using a digitising tablet attached to a microcomputer and expressed as a percentage of the total area of lung. In cases with centriacinar emphysema the number of discrete lesions was counted. The area of macroscopic emphysema ranged from 0 to 78% of the total area of lung examined, but most patients had less than 1% involvement so that the distribution was highly skewed. Both mean airspace wall surface area per unit volume and the mean of five fields with the lowest airspace wall surface area per unit volume were normally distributed, with mean airspace areas ranging from 8.8 to 25.4 mm2/mm3 (mean 18.1 mm2/mm3). In lobes with centriacinar emphysema the number of discrete lesions correlated with airspace wall surface area per unit volume and with preoperative carbon monoxide transfer factor (TLCO) per unit lung volume. However, other measurements of macroscopic emphysema did not correlate with loss of alveolar wall surface area, and there was considerable overlap between subjects with no or minimal macroscopic emphysema and those with more severe disease. TLCO correlated with both mean airspace wall surface area per unit volume and the mean of five fields with the lowest airspace wall surface area per unit volume but not with the severity of macroscopic emphysema. If emphysema is to be quantified it must be measured microscopically; macroscopic measurements do not, in general, reflect the microscopic loss of airspace wall.


Somnofluoroscopy, computed tomography, and cephalometry in the assessment of the airway in obstructive sleep apnoea.

Assessments of the upper airways in patients with the obstructive sleep apnoea syndrome are usually carried out on awake patients who are upright. The dynamics of the airway in a patient who is asleep and lying down may be different. Somnofluoroscopy, computed tomography of the upper airway, and cephalometry were carried out in 11 patients with the obstructive sleep apnoea syndrome (10 male; mean (SD) age 53 (10) years) to examine the airway while they were awake and asleep. At somnofluoroscopy 10 patients were in stage 2 sleep and only one in REM sleep. At least five obstructive events were visualised by lateral fluoroscopy in each patient. Imaging allowed observation of the dynamics of airway collapse, which began in the oropharynx in all cases, progressing to the hypopharynx in 10 cases and to the laryngopharynx in five. At fluoroscopy the soft palate was seen to hook up during airway occlusion in 10 patients, thereby increasing its cross sectional area. It was then sucked down into the hypopharynx. Somnofluoroscopic and cephalometric findings agreed, eight of the 10 patients with hypopharyngeal collapse shown by somnofluoroscopy having an inferiorly placed hyoid bone according to cephalometry (distance from the mandibular plane to the hyoid bone (MP-H distance) increased); the one patient with no hypopharyngeal collapse had a normal MP-H. By contrast, six of the 11 patients had a normal or supranormal hypopharyngeal cross sectional area of the airway on the computed tomogram. Somnofluoroscopy allows examination of the dynamics of airway closure in this disorder and shows the important role of the soft palate in acting as a plug in the oropharynx. Dynamic studies are required to determine the pattern of pharyngeal obstruction in obstructive sleep apnoea.


Habitual snoring with and without obstructive sleep apnoea: the importance of cephalometric variables.

The obstructive sleep apnoea syndrome is characterised by an increased apnoea-hypopnoea index and a reduction in the minimal arterial oxygen saturation (SaO2) values during sleep. The extent to which these variables can be predicted by cephalometric and otorhinolaryngological variables was tested. One hundred consecutive habitual snorers (84% male), with a mean (SD) age of 50.1 (10.1) years, were studied. The 45 patients with less severe sleep apnoea, with an apnoea-hypopnoea index of 10 or less (group A), were compared with the 55 with an index above 10 (group B). Body mass index, some cephalometric variables, and some otorhinolaryngological variables differed significantly between group A and group B, in particular the soft tissue measures PNS-P (posterior nasal spine to palate), MP-H (mandibular plane to hyoid bone), degree of oropharynx stenosis, and tongue size. In a multiple regression correlation analysis MP-H, SNB (angle from sella to nasion to subspinale point), SNA (angle from sella to nasion to supramentale point), PAS (posterior airway space), tongue size, and body mass index contributed significantly to the equation explaining the severity of sleep apnoea. Nevertheless, these variables together explained only 33% of the variance of the apnoea-hypopnoea index in the total sample; they were more important for patients with moderate to severe stages of the disease. The lack of association between cephalometric variables and mild sleep apnoea suggests that the differences in these variables (soft tissue measures) may be the consequence rather than the cause of habitual snoring and the obstructive sleep apnoea syndrome.


Validity of peak expiratory flow measurement in assessing reversibility of airflow obstruction.

Assessing the reversibility of airflow obstruction by peak expiratory (PEF) measurements would be practicable in general practice, but its usefulness has not been investigated. PEF measurements were performed (miniWright peak flow meter) in 73 general practice patients (aged 40 to 84) with a history of asthma or chronic obstructive lung disease before and after 400 micrograms inhaled sulbutamol. The change in PEF was compared with the change in forced expiratory volume in one second (FEV1). Reversible airflow obstruction was analysed in two ways according to previous criteria. When defined as a 9% or greater increase in FEV1 expressed as a percentage of predicted values reversibility was observed in 42% of patients. Relative operating characteristic analysis showed that an absolute improvement in PEF of 60 l/min or more gave optimal discrimination between patients with reversible and irreversible airflow obstruction (the sensitivity and specificity of an increase of 60 l/min in detecting a 9% or more increase in FEV1 as a percentage of predicted values were 68% and 93% respectively, with a positive predictive value of 87%). When defined as an increase of 190 ml or more in FEV1, reversible airflow obstruction was observed in 53% of patients. Again an absolute improvement in PEF of 60 l/min or more gave optimal discrimination between patients with reversible and irreversible airflow obstruction (sensitivity 56%, specificity 94%, and positive predictive value 92%). Absolute changes in PEF can be used as a simple technique to diagnose reversible airflow obstruction in patients from general practice.


Single breath transfer factor for carbon monoxide in an asymptomatic population of never smokers.

Data on reference values of transfer factor variables in general populations of asymptomatic never smokers are limited. The aim of this study was to examine the relation between test variables and age, height, haemoglobin concentration and carboxyhaemoglobin concentration. Measurements of single breath transfer factor for carbon monoxide (TLCO) were obtained for a randomly selected sample of never smokers in north western Europe who were 18-73 years old and had no respiratory symptoms or disorders. Two recordings of TLCO with a ratio of inspiratory vital capacity to forced vital capacity of greater than 0.09 were obtained by standardised techniques for 304 subjects. The measurement errors expressed as a percentage of the common mean value of TLCO, volume adjusted TLCO (KCO), and alveolar volume (VA) were 4.5%, 4.2%, and 2.4% respectively. Multiple linear regressions showed sex specific effects of height and age on TLCO, and, in addition, of haemoglobin and carboxyhaemoglobin concentrations on KCO. VA was associated with height but not with age. The 5th and 95th centiles for TLCO and KCO in men and women were between 78% and 82% and between 120% and 127%, respectively, of predicted values when age and height were taken into account. Reference equations and normal values for transfer test variables in a large healthy population of never smokers are described in relation to age, height, and haemoglobin concentrations. To our knowledge, this is the first report of an association between carboxyhaemoglobin concentrations and KCO in a population of never smoking men and women.


Localised pulmonary metastatic calcification associated with pulmonary artery obstruction.

Metastatic pulmonary calcification, a complication of uraemia and disordered calcium metabolism, may be diffuse or localised. The factors that determine calcium precipitation are complex, but tissue alkalosis is thought to be important. As obstruction of the pulmonary artery theoretically causes local alkalosis a retrospective necropsy study was carried out to examine the relation between metastatic pulmonary calcification and vascular obstruction. Five patients with focal and two with diffuse metastatic calcification in the lungs were identified over eight years. Lungs were studied macroscopically and by light microscopy, haematoxylin and eosin and histochemical stains being used for calcium. Underlying risk factors for calcification in these patients included renal failure in six and disseminated malignancy in five. In the five patients with localised calcification obstruction of the pulmonary artery by thrombus or tumour was found proximal or adjacent to areas of calcium deposition. In two patients metastatic calcification was confined to a lung with unilateral pulmonary artery thromboembolic occlusion. Calcification was not specifically associated with infarction, pneumonia, or diffuse alveolar damage. Lesions of the pulmonary artery were not seen in the two patients with diffuse bilateral metastatic calcification. In this small series there was a spatial association between pulmonary artery obstruction and localised metastatic calcification. It is proposed that pulmonary artery obstruction alters the microchemical environment of the lung, favouring tissue alkalosis and thereby enhancing parenchymal calcification in patients predisposed to this condition.


Surgical closed pulmonary valvotomy for critical pulmonary stenosis: implications for the balloon valvuloplasty era.

Closed pulmonary valvotomy for critical pulmonary stenosis has no apparent advantage over the percutaneous balloon technique, though it is used when balloon valvuloplasty fails. Experience of this technique at the Heart Institute, Tel Hashomer, since it was first used in 1973 has been reviewed. Thirty eight infants up to 1 year old (25 of them neonates--that is, nil to 1 month old) with critical pulmonary stenosis were operated on from 1973 to 1989. All had a transventricular valvotomy, by a modification of the Brock method, and all underwent cardiac catheterisation before surgery. Five of the 25 neonates (20%) died, but none of the other infants, so that the total mortality (five out of 38) was 13%. Three of the 38 required an aortopulmonary shunt. All 38 survivors were followed up--from one month to 14 years (mean 7.5 years). All were symptom free at the last check up. Fifteen of the survivors had required further surgery; this was successful in all cases. For the balloon valvuloplasty era surgical pulmonary valvotomy provides a good back up for failed attempts at percutaneous valvuloplasty. Review of outcome provides data for comparison with balloon valvuloplasty in the future.


An unusual cause of bilateral diaphragmatic paralysis.

In a patient who had a sudden onset of bilateral diaphragmatic paralysis after forceful neck manipulation complete, though gradual, recovery in lung function and transdiaphragmatic pressures was seen over three years. This is a previously unrecognised risk of neck osteopathy.


Cystic fibrosis in a 70 year old woman.

A 68 year old woman with a lifelong history of chronic bronchitis was diagnosed as having cystic fibrosis. The diagnosis was based on a suggestive family history, steatorrhoea, bronchiectasis with respiratory insufficiency, and very high sweat sodium content. The patient was found to be heterozygous for the delta F 508 gene defect.


Removal of endobronchial mucormycosis lesion through a rigid bronchoscope.

A 44 year old man with poorly controlled diabetes mellitus developed endobronchial mucormycosis, which totally obstructed the right lower lobe bronchus. The lesion was removed through a rigid bronchoscope. Two weeks later the bronchus was free of mucormycosis histologically and on culture.


Horseshoe lung with left lung hypoplasia.

Horseshoe lung is an uncommon congenital malformation in which the bases of the right and the left lungs are fused to each other by a narrow isthmus posterior to the cardiac apex. So far 22 cases have been described: most of these were associated with right lung hypoplasia and the scimitar syndrome. A horseshoe lung anomaly with left lung hypoplasia is described.


Lupus anticoagulant activity is frequently dependent on the presence of beta 2-glycoprotein I.

Antiphospholipid antibodies (aPL) are defined by anticardiolipin antibody (aCL) ELISA and prolongation of phospholipid dependent coagulation assays (lupus anticoagulant; LAC). For the binding of aCL to cardiolipin a cofactor, beta 2-glycoprotein I (beta 2-GPI), is necessary. We have investigated whether the same cofactor is essential for LAC activity. Plasma from 6 LAC positive patients and 3 controls was depleted from beta 2-GPI by means of affinity chromatography. From the 6 LAC positive plasmas, 4 became LAC negative (tested with dRVVT) when beta 2-GPI was depleted and became positive again when purified beta 2-GPI (200 micrograms/ml) was added. A dose response curve showed that addition of 50 micrograms/ml beta 2-GPI to beta 2-GPI deficient patient plasma, led to a positive dRVVT. Depletion of, and addition of beta 2-GPI to plasma from controls had no effect on the dRVVT. Measurement of beta 2-GPI plasma levels in 19 LAC positive patients, 40 LAC negative patients and 15 controls showed no difference in beta 2-GPI levels. These results show that a combination of aPL and beta 2-GPI is essential not only for binding to cardiolipin, but also for LAC activity and imply that low beta 2-GPI levels (less than 50 micrograms/ml) can lead to false negative LAC tests. These observations may lead to new insights in the pathophysiological complications associated with aPL.


Gemfibrozil reduces plasma prothrombin fragment F1 + 2 concentration, a marker of coagulability, in patients with coronary heart disease.

The effects of gemfibrozil on several indices of haemostatic activity were explored in male patients with coronary heart disease (CHD). Sixty-three of 71 patients completed a crossover study in which gemfibrozil 1,200 mg/day and matching placebo were each taken in randomised order for 2 months in a double-blind manner, separated by a 2-month washout period. Serum cholesterol decreased by an average (95% confidence interval) of 12 (9 to 15)% and non-fasting triglyceride concentration by 43 (34 to 51)% during active treatment. Plasma prothrombin fragment F1 + 2 concentration, a marker of the in vivo rate of generation of thrombin, was 25 (12 to 37)% lower on average while on gemfibrozil than during the placebo phase. Factor VII coagulant activity (VIIc) and antigen concentration, and fibrinopeptide A concentration were not influenced by gemfibrozil in the group overall. However, the VIIc response appeared to be dependent upon the untreated cholesterol level. Hypercholesterolaemic men (cholesterol greater than 6.5 mmol/l) experienced a significant reduction in VIIc averaging 6% of standard during active therapy. Other effects of gemfibrozil were a 5 (2 to 9)% increase in plasma fibrinogen by a gravimetric method, an 11 (8 to 13)% increase in platelet count, and a 6 (2 to 10)% reduction in white cell count. The reduced incidence of CHD following gemfibrozil therapy in hyperlipidaemic patients may arise in part through a reduction in procoagulant activity and thus the risk of an occlusive coronary thrombosis.


The use of the D-dimer test in combination with non-invasive testing versus serial non-invasive testing alone for the diagnosis of deep-vein thrombosis.

We studied the usefulness of the determination of plasma D-dimer levels (using an ELISA) in combination with non-invasive testing with impedance plethysmography (IPG) or real-time ultrasonography (US) for the diagnosis of deep-vein thrombosis (DVT), in outpatients with clinically suspected DVT. This combined approach was compared to serial non-invasive testing alone in these patients. The sensitivity of a positive D-dimer test (greater than 300 micrograms/l) for the presence of DVT was 100% (70/70 patients; 95% C.I.: 95-100%), whereas the specificity was 29% (69/239 patients; 95% C.I.: 23-34%). The proportion of patients in which a definitive decision about the presence or absence of DVT could be made on the day of referral, was calculated for both approaches. When applying the combined approach, in 42% of all referred patients the diagnosis of DVT could either be established or refuted on entry, as opposed to only 19% of patients using serial non-invasive testing alone. Also, the costs per DVT diagnosed were calculated for the two diagnostic approaches. For the diagnosis of DVT the costs using serial IPG were comparable to the costs using the combination of IPG and the D-dimer test. The same conclusion holds for the comparison of serial US with the combination of US and D-dimer testing. We conclude that for the diagnosis of DVT in symptomatic outpatients the combination of non-invasive testing with the D-dimer test might be preferred over serial non-invasive testing alone, although the safety of such an approach remains to be established in future management studies.


A randomized and blinded comparison of three bleeding time techniques: the Ivy method, and the Simplate II method in two directions.

We compared the Ivy bleeding time method and two alternatives of the Simplate II method (incisions in horizontal and vertical direction) with each other, with regard to the sensitivity, the specificity, the costs and the burden for the patient. In the aspirin study an aspirin-induced bleeding defect was used. Seventy-two healthy volunteers were randomized to receive either 500 mg acetylsalicylic acid (ASA) or a placebo. Double blinding was maintained throughout the study. In the anticoagulation study 62 patients participated, who received oral anticoagulants (OAC) for various reasons. All participants received two bleeding time methods. The burden for the participants of each method was screened by a small standard questionnaire. The differences in sensitivity and specificity between the three methods proved minimal. The Ivy method was more often preferred by the participants than the Simplate methods. Since a choice on the basis of sensitivity and specificity appears not possible, we prefer the Ivy method because of lower costs and less burden.


Venous thrombosis during pregnancy: leg and trimester of presentation.

In order to determine the relative frequencies of left and right leg venous thrombosis during pregnancy and the frequencies of venous thrombosis during the three trimesters, a cohort study of 60 consecutive patients with a first episode of venous thrombosis during pregnancy was performed. Fifty-eight women had isolated left leg thrombosis, two patients had bilateral venous thrombosis and no patient had isolated right leg venous thrombosis. Thirteen patients had venous thrombosis during the first trimester (21.7%), 28 during the second trimester (46.7%) and 19 during the third trimester (31.7%). These findings indicate that patients with symptoms in the right leg rarely have venous thrombosis. Because leg pain and swelling occur most frequently during the third trimester but venous thrombosis is relatively equally distributed during all three trimesters, patients presenting earlier during pregnancy are more likely to have venous thrombosis than patients presenting later during pregnancy.


In vivo significance of kinetic constants of tight binding reversible proteinase inhibitors.

For a reaction between an enzyme and inhibitor, rate constants and equilibrium constants are both widely used as measures of inhibitor potency. Which one of these two parameters should be used depends on the mechanism of the reaction. Moreover, for biological studies it is not always the overall effectiveness of an inhibitor that is important, but also the rate at which it acts in conditions that may be encountered in vivo. In vitro investigations may be performed to determine the kinetic and thermodynamic constants in an enzyme inhibitor system and to investigate the influence of various other effector biomolecules. However, in translating these results into physiological conclusions, care must be taken that the in vitro experiments have been properly designed and data analysed correctly. This article is an attempt to indicate some of the problems that can be encountered in this process.


Effect of leukocyte proteinases on tissue factor pathway inhibitor.

The effect of human neutrophil elastase and cathepsin G on recombinant tissue factor pathway inhibitor (TFPI) was investigated. A weak inhibition by TFPI of both elastase (Ki = 0.4 microM) and cathepsin G (Ki = 0.1 microM) was observed. Neutrophil elastase rapidly cleaved TFPI at the Thr87-Thr88 bond situated at the link between Kunitz domains I and II. Cleavage of TFPI by cathepsin G was also observed, but the reaction was much slower and resulted in a number of fragments. Proteolytic cleavage by both elastase and cathepsin G resulted in destruction of inhibitor function with respect to TFPI's inhibition of factor Xa. Cleavage by neutrophil elastase was capable of restoring factor Xa amidolytic activity after its initial inhibition by TFPI. Inhibition of cathepsin G by TFPI was strongly augmented by stoichiometric amounts of factor Xa. However, the augmentation was temporary, presumably due to concomitant cleavage of TFPI by cathepsin G. These observations may have implications for the putative effect of neutrophil leukocyte stimulation on the regulation of the tissue factor-mediated coagulation pathway. Conversely, formation of a factor Xa/TFPI complex may reduce or modulate the proteolytic potential of stimulated leukocytes by temporary inhibition of cathepsin G.


Measurement of markers of activated coagulation in antithrombin III deficient subjects.

Functional antithrombin III levels were measured by factor Xa inhibition in 63 members of a large family with type 2 antithrombin III deficiency and individuals were classified as antithrombin III deficient or non-deficient according to the results. F1 + 2 and TAT complexes were measured using an ELISA and FPA levels were measured by radioimmunoassay. Thirty subjects (48%) were classified as antithrombin III deficient and 33 (52%) as antithrombin III non-deficient. The mean level of F1 + 2 was significantly higher in the deficient adults (0.87 +/- 0.26) compared to both the non-deficient adults (0.70 +/- 0.21) (p = 0.03) and the deficient adults receiving warfarin (0.16 +/- 0.01) (p less than 0.001). The differences in the mean values of TAT complexes and FPA between deficient and non-deficient individuals were not statistically significant. These findings suggest that untreated antithrombin III deficient subjects generate more thrombin than their non-deficient family members and that warfarin inhibits this thrombin formation. In this cross-sectional study, it is not possible to correlate the levels of the surrogate makers with future clinical outcome.


Effects of splenectomy on immune thrombocytopenic purpura in (NZW x BXSB) F1 mice: analyses of platelet kinetics and anti-platelet antibody production.

Effects of splenectomy on platelet kinetics and production of anti-platelet antibodies were studied in male (NZW x BXSB) F1 (W/B F1) mice, which are known as the animal model of immune thrombocytopenic purpura (ITP). Studies on organ localization of radiolabeled platelets revealed that splenic uptake significantly increases in W/B F1 mice in comparison with that of normal controls. W/B F1 mice showed a significant increase in platelet counts and, in contrast with sham-operated controls, high levels of platelet counts were maintained up to 6 weeks after splenectomy. Platelet lifespans (PLSs) did not reach normal levels, although prolonged PLSs were observed. In addition, platelet-associated antibody (PAA) values showed a tendency towards transient decrease, but there was no change in platelet-bindable serum antibodies (PBAs). These findings indicate that the suppression of anti-platelet antibody production is essential to the treatment of ITP; splenectomy may not be effective in treating severely affected ITP patients because, although the spleen is one of the major sites of platelet sequestration and antibody production, reticulo-endothelial systems (RESs) (liver, bone marrow, lymphnodes, etc.) other than the spleen are also responsible for the destruction of platelets. We therefore consider the W/B F1 mouse to be a useful model of human ITP, and believe that it provides valuable information for the development of new therapeutic agents in patients with ITP, especially those who do not respond to splenectomy.


Membrane fluidity is related to the extent of glycation of proteins, but not to alterations in the cholesterol to phospholipid molar ratio in isolated platelet membranes from diabetic and control subjects.

Platelets from diabetic subjects are hypersensitive to aggregating agents in vitro. Membrane fluidity modulates cell function and we previously reported reduced membrane fluidity associated with hypersensitivity to thrombin in intact platelets from diabetic subjects. Reduced membrane fluidity and hypersensitivity to agonists has also been reported in platelets from non-diabetic subjects whose platelets have an increased cholesterol/phospholipid molar ratio. Glycation of platelet membrane proteins is enhanced in diabetic subjects, and could contribute to the decreased membrane fluidity in these platelets. We examined the relation among fluidity, cholesterol/phospholipid molar ratio, and glycation of proteins in isolated platelet membranes from diabetic and control subjects. Seven poorly controlled diabetic subjects were compared with 7 age- and sex-matched control subjects. The mean steady-state fluorescence polarization value in 1,6-diphenyl-1,3,5-hexatriene-labeled isolated platelet membranes from diabetic subjects (0.184 +/- 0.004) was significantly greater than from control subjects (0.171 +/- 0.004, p less than 0.01); thus, fluidity in platelet membranes from diabetic subjects is decreased. Reduced fluidity in platelet membranes from diabetic subjects could not be attributed to changes in the cholesterol/phospholipid molar ratio. Total or very low density (VLDL), low density (LDL), or high density (HDL3) lipoprotein cholesterol concentration in plasma was not significantly different between groups, but the ratio of VLDL+LDL to HDL2 + HDL3 cholesterol was significantly greater in diabetic subjects (4.79 +/- 0.73) than in control subjects (2.54 +/- 0.30, p less than 0.02). Proteins were glycated significantly more extensively in platelet membranes from diabetic subjects (25.5 +/- 0.9 nmol glucose/mg protein) than those from control subjects (21.0 +/- 0.6 nmol glucose/mg protein, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)


Assessment of lumiaggregometry for research and clinical laboratories.

Platelet aggregometry is often used to help diagnose storage pool disease (SPD-reduced amounts of granule nucleotides) and release defects (abnormal release of granule nucleotides). The general assumption that normal aggregation patterns are sufficient to rule out the diagnosis of one of these disorders has been invalidated by the recent publication of two papers describing patients with clinical bleeding, prolonged bleeding times and normal aggregation patterns in spite of defective release. The lumiaggregometer provides a tool for measuring platelet release and aggregation simultaneously. This paper presents a standardized, reproducible method for the use of the lumiaggregometer based on a "standard curve". Data obtained during the development of the procedure are presented including normal ranges of release at different concentrations of agonists, release measured in intrinsic disorders as well as in patients on aspirin, and values for release relative to varying platelet counts. A monoclonal antibody (anti-p24/CD9; MAb7) which activates platelets similarly to thrombin and may be a useful reagent for distinguishing SPD and release defects is also introduced.


Effects of injected antibody against the platelet glycoprotein IIb/IIIa complex on monkey platelet fibrinogen.

Four monkeys were injected for a 10-day period with the Fab fragment of a murine monoclonal antibody (NNKY 1-32) which inhibits the binding of fibrinogen to the platelet glycoprotein (GP) IIb/IIIa complex. Platelet fibrinogen levels were assessed quantitatively by electroimmunoassay and qualitatively by immunoelectron microscopy. The platelet fibrinogen level fell to 9.0 +/- 2.8% of the control level after antibody administration. Immunoelectron microscopy showed that the injected antibody was localized on the inner surface of the platelet alpha-granule membrane. Our findings suggest that the GP IIb/IIIa complex can be internalized by alpha-granules and that it may mediate the endocytosis of plasma fibrinogen by platelets.


Characterization of the phosphorylated state of protein 4.2 from a patient partially deficient in protein 4.2.

These studies compare the protein 4.2 found in a patient with osmotically fragile, spherocytic erythrocytes to the normal protein 4.2. The patient protein 4.2 is present in the erythrocyte ghost membranes as a doublet of 74 and 72 KDa at a concentration less than 1% of normal. The patient protein 4.2 becomes highly phosphorylated in the presence of Zn++ and is phosphorylated, relative to the amount of protein present, to a greater extent than the normal 72 KDa protein 4.2. These studies indicate that both the patient and the normal protein 4.2 usually exists in a highly phosphorylated state. The phosphorylation sites on the patient protein 4.2 appear to be more readily cycled than on the normal protein 4.2. Staphylococcus aureus V8 protease generates similar phosphopeptides in both the normal and patient protein 4.2 except for an extra 11 KDa phosphopeptide generated from the 74 KDa form of the protein.


Zinc ions and alkaline pH alter the phosphorylated state of proteins 3 and 4.2 in human erythrocyte membranes.

The phosphorylation patterns of isolated red blood cell (RBC) membranes labeled with [gamma-32P] ATP are altered by Zn++ ions. Zn++ ions caused an increased phosphate incorporation into a 72 KDa protein and several proteins in the 40-60 KDa region and a decrease in the labeling of a 53 KDa protein. The 72 KDa and 53 KDa proteins have been identified as protein 4.2 and a protease-cleaved fragment of protein 3, respectively. Evidence suggests that the changes in phosphorylation pattern may be due to the stimulation of endogenous membrane alkaline phosphatase(s). Our results suggest that Zn++, at physiological concentrations in the intact erythrocyte, could modulate the phosphorylation of selected proteins which may regulate their association in the cytoskeletal network.


Effect of heparin on in vitro platelet reactivity in cardiac surgical patients--a comparative assessment by whole blood platelet aggregometry and haemostatometry.

The in vitro effect of heparin on platelet reactivity was assessed simultaneously by haemostatometry (response to shear stress) and whole blood platelet aggregometry response to collagen (WBPA). From each blood sample a ratio (HR for haemostatometry and MR and IR for WBPA) showing platelet reactivity in the presence or absence of heparin (5 U/ml) was calculated. A value less than 1 represented a proaggregatory effect and greater than 1 an inhibitory effect. Non-anticoagulated blood samples obtained from 290 cardiac surgical patients were tested by haemostatometry and citrated whole blood samples from 100 patients with aggregometry. Haemostatometry demonstrated a proaggregatory effect of heparin in 8.6% (25) and an inhibitory effect in 91.4% (265). Assessed by WBPA, heparin was proaggregatory in 41-46% and inhibitory in 54-59%. In the 100 patients tested by both methods there was a significant correlation between the findings with the two techniques (r = 0.46, p less than 0.0001). A wide individual variation in the platelet effect of heparin was demonstrated. This variation appeared greater and a higher proportion showed inhibition when blood was tested by haemostatometry.


The in vivo effect in humans of pyridoxal-5'-phosphate on platelet function and blood coagulation.

Vitamin B6 has an antithrombotic effect. This, based on the results of in vitro studies, has been attributed to an antiplatelet effect. We assessed the in vivo effect of vitamin B6 by measuring the effect of long-term administration of vitamin B6 on platelet function and blood coagulation. Vitamin B6 (pyridoxine hydrochloride), 100mg twice daily p.o. for fifteen days, was administered to 10 healthy volunteers. The bleeding time was measured before the first dose and 15 days after. A baseline value, the acute effect, chronic effect, and the acute-on-chronic effect of vitamin B6 was estimated by measuring platelet function. The following tests were performed: platelet aggregation induced by collagen, ADP and epinephrine; thromboxane A2 (TxA2)-production and prostacyclin inhibition of ADP-induced aggregation. The effects on the coagulation system were monitored by measuring: the prothrombin time, activated partial thromboplastin time and levels of coagulation factor. Vitamin B6 significantly prolonged the bleeding time from 4.1 +/- 1.1 minutes to 6.8 +/- 1.0 minutes (p = 0.0063). Aggregation of platelets with collagen was slightly but not significantly inhibited. Platelet aggregation induced with the agonists ADP or epinephrine was significantly inhibited by vitamin B6, and the platelets tended to aggregate at a slightly decreased rate. The mean TxA2-production was slightly, but not significantly, decreased. Vitamin B6 had no effect on the sensitivity of platelets to prostacyclin, or on the coagulation system. Our results indicate that the antithrombotic effects of vitamin B6 is limited to inhibition of platelet function; there was no measurable influence on coagulation. The results of this in vivo study are however such that clinical trials are warranted to further assess the efficacy of vitamin B6 as an antiplatelet drug.


Triflavin, an Arg-Gly-Asp containing snake venom peptide, inhibits aggregation of human platelets induced by human hepatoma cell line.

Triflavin, an Arg-Gly-Asp (RGD)-containing peptide, purified from snake venom of Trimeresurus flavoviridis, inhibits human platelet aggregation through the blockade of fibrinogen binding to fibrinogen receptors associated with glycoprotein IIb/IIIa complex. In this report, we examined the effect of triflavin on tumor cells (human hepatoma J-5)-induced platelet aggregation (TCIPA) of heparinized platelet-rich plasma (PRP). ADP-scavenger agents, apyrase (10 U/ml) and creatine phosphate (5 mM)/creatine phosphokinase (5 U/ml) did not inhibit TCIPA while hirudin (5 U/ml) completely inhibited it. J-5 cells initially induced platelet aggregation, then blood coagulation occurred. J-5 cells concentration-dependently shortened the recalcification time of normal as well as Factor VIII, IX-deficient human plasmas, while it was inactive at shortening the recalcification time of Factor VII-deficient plasma, suggesting J-5 cells induced platelet aggregation through activation of extrinsic pathway, leading to thrombin formation as evidenced by the amidolytic activity on s-2238 by expressing tissue factor-like activity. Triflavin inhibited TCIPA in a dose-dependent manner (IC50, 0.02 microM). When compared on molar ratio, triflavin was approximately 30,000 times more potent than GRGDS (IC50, 0.58 mM). On the other hand, GRGES showed no significant effect on TCIPA, even its concentration was raised to 4 mM. Additionally, the monoclonal antibodies, raised against glycoprotein IIb/IIIa complex (i.e., 7E3 and 10 E5) inhibited J-5 TCIPA. In conclusion, we suggest the inhibitory effect of triflavin on J-5 TCIPA may be chiefly mediated by the binding of triflavin to the fibrinogen receptor associated with glycoprotein IIb/IIIa complex on platelet surface membrane.


Comparative studies of drotaverine--acephyllinate (Depogen) and pentoxifylline (Trental).

Pentoxifylline is an orally active agent for the treatment of peripherial and cerebral vascular diseases. Pentoxifylline increases the deformability of red blood cells in vitro, reduces blood viscosity and decreases platelet aggregation and thrombus formation. Depogen has shown antiaggregatory effect both in vitro and in ex vivo. The inhibitory effect of Pentoxifylline was about 3-5 times weaker than that of Depogen. IC50 = 900/micrograms/ml for Depogén and 3600/micrograms/ml for Pentoxifylline on human platelet rich plasma. Depogen has shown ex vivo antiaggregatory effect on anesthetised rabbits, ID50 = 7 mg/kg in case of iv. administration, and ID50 = 300 mg/kg in case of orally administration. Both compound inhibit the release of platelet precoagulation factor, but the effect of Pentoxifylline was slighter.


Pharmacology of r-hirudin in renal impairment.

The pharmacokinetic properties of r-hirudin were studied in nine patients suffering from different degrees of renal insufficiency. To this end, r-hirudin was administered intravenously at dosages of 0.1 mg/kg. The elimination half-life t1/2 beta was determined in blood plasma and the cumulative r-hirudin excretion in urine was measured over 48 h. In healthy volunteers t1/2 beta was 0.9 +/- 0.2 h; the cumulative r-hirudin excretion in urine after 48 h amounted to 38 +/- 10% of the dose administered, most of this quantity was excreted during the first hours. In seven patients with chronic renal failure, t1/2 beta was 15 to 41 h; in three of these patients cumulative urinary r-hirudin excretion was increased to 70-80%, in four patients cumulative r-hirudin excretion in urine within 48 h amounted to 39 +/- 8%, but was delayed in time. In 2 bilaterally nephrectomized patients, t1/2 beta was 168 and 316 h, resp. The renal clearance of hirudin was significantly and linearly correlated with the creatinine clearance (r = 0.872). In all patients aPTT and bleeding time were only moderately prolonged. Because of the modified pharmacokinetic behaviour the administration of hirudin in patients with impaired renal function requires individually adjusted dosages or prolonged administration intervals.


Direct evidence for systemic fibrinogenolysis in a patient with metastatic prostatic cancer.

Although the possible occurrence of systemic fibrinogenolysis has been suggested in patients with metastasising prostatic cancer (MPC), direct evidence is lacking. We report on a patient with MPC whose laboratory data were consistent with hyperfibrinolysis: marked decrease of alpha 2-antiplasmin (AP) level (less than 50% of normal), increase of plasmin-alpha 2-antiplasmin complex, D-fragment of fibrin and fibrinogen degradation products [FDP(D)] and cross-linked fibrin degradation products (XDP). The patient neither showed laboratory nor clinical evidence for consumption coagulopathy except for a slight increase in thrombin-antithrombin III complex level. Immunoblotting of the patient's serum using an anti-fibrinogen antibody revealed the presence of a 250 kDa protein in addition to DD fragments. Following reduction of this protein by 2-mercaptoethanol after extraction from SDS-PAGE gel, gamma-chain of fibrinogen (47 kDa) was found by immunoblotting using a monoclonal antibody recognising a 86-302 residue of the gamma-remnant of fibrinogen. Moreover, the 250 kDa protein did not bind to Sepharose 4B to which a monoclonal antibody recognising the N-terminus of fragment D was conjugated. These findings indicated that this protein was not fragment DY, but rather fibrinogen fragment X. With the retraction of the prostatic tumour by an effective therapy, the patient's AP level increased gradually. When the plasma AP level rose to 60% of normal, the fragment X was no longer detectable. These findings suggested that systemic fibrinogenolysis occurred in the patient with MPC only when AP levels were markedly decreased.


Recurrent venous thrombosis during warfarin treatment related to acquired protein S deficiency.

Failure of warfarin to prevent new thrombotic processes was observed in three patients with very low free protein S concentrations and high C4b-binding protein (C4bBP) concentrations, and in one patient with hereditary protein S deficiency. We suggest that an increase in C4bBP reduces the free Protein S level, and warfarin treatment causes an additional decrease of free protein S. The four patients presented indicate that such reductions are of clinical importance. Heparin seems preferable as an anticoagulant in this situation, as warfarin given alone is ineffective, or may even be harmful. In a group of pancreatic cancer patients with advanced disease, subnormal mean free protein S was found, whereas mean total protein S concentration, and mean C4bBP concentrations were significantly higher (p less than 0.01) than in healthy controls. These findings indicate that an increase in C4bBP may induce free protein S deficiency contributing to the increased thrombotic tendency in this group of patients. The correlation between free protein S and C4bBP was 0.11, (n.s.), between total protein S and C4bBP 0.73 (p less than 0.0001).


Laboratory monitoring of thromboprophylaxis with low molecular weight and standard heparin.

This study was made to evaluate assays for monitoring of low dose heparin thromboprophylaxis and to evaluate its efficacy in reduction of hypercoagulation. Patients with medical diseases scheduled for routine thromboprophylaxis were subcutaneously treated with either 5.000 anti XaU low molecular weight (LMW) heparin once daily (n = 20) or 5.000 IU standard (ST) heparin 3 times daily (n = 19). On days 1,2,3, before, 1 and 4 hours after heparin injection APTT, TCT, anti Xa, Heptest, thrombin-antithrombin complexes (TAT), and D-Dimer levels were measured. In the LMW heparin group, median values of APTT and TCT slightly increased after heparin and the ranges of pre- and postinjection values showed extensive overlap. However, values of anti Xa and Heptest markedly increased, showing complete separation of ranges. In the ST heparin group neither APTT, TCT, anti Xa, nor Heptest were significantly different comparing pre- and postheparin values. Half of the patients in both groups had subclinical hypercoagulation at baseline (TAT greater than 5 ng/ml, D-Dimer greater than 200 ng/ml). On day 3 of prophylaxis this percentage was not significantly decreased. Moreover, several patients in both groups increased in TAT and D-Dimer. In the LMWheparin group, negative correlations between body weight and 4 h postinjection heparin levels were found (anti Xa R = -0.50, Heptest R = -0.31) and between 1 h postinjection heparin and TAT and D-Dimer levels 3 h later (TAT-anti Xa R = -0.58, TAT-Heptest R = -0.64, D-Dimer-anti Xa R = -0.32, D-Dimer-Heptest R = -0.33).(ABSTRACT TRUNCATED AT 250 WORDS)


Replacement of m-calpain by mu-calpain during maturation of megakaryocytes and possible involvement in platelet formation.

Localization of calpains in human bone marrow cells was studied immunohistochemically employing monoclonal antibodies against the high-Ca(2+)-requiring form (m-calpain) and the low-Ca(2+)-requiring form (mu-calpain). Most cells were stained with anti-m-calpain more strongly than with anti-mu-calpain, and staining with anti-mu-calpain was prominent only in megakaryocytes. To confirm the result, megakaryoblastic cell line (T-33) cells were subjected to immunoblot analysis. However no immunoreactivity to mu-calpain was seen in T-33 cells. Bone marrow from a patient with idiopathic thrombocytopenic purpura showed immature megakaryocytes (stage II) strongly stained by anti-m-calpain antibody while mature cells (stage III) were strongly stained by anti-mu-calpain antibody. These results suggest that mu-calpain plays a crucial role in mature megakaryocytes, possibly in platelet production.


Blood serotonergic mechanisms in type 2 (non-insulin-dependent) diabetes mellitus.

Serotonin (5-hydroxytryptamine, 5HT) is believed to play a role in vasospasm and increased platelet aggregability that in turn could contribute to atherosclerosis. The present study was designed to evaluate a possible participation of serotonin in the development of vascular complications in diabetes mellitus. Whole blood and plasma serotonin, the platelet uptake and release of the amine and serotonin- induced platelet aggregation were studied in 32 patients with Type 2 diabetes. The patients were divided into three groups according to the presence and advancement of retinopathy. Mean levels of blood serotonin content were significantly lower in diabetic patients. The concentration of the amine in the plasma was markedly increased in diabetes. It was correlated with vascular changes of the retina. We established that platelets from diabetic patients took up less serotonin when compared to the control group. Concomitantly enhanced spontaneous release of 5HT from platelets was observed. The platelets of diabetic patients showed increased response to serotonin. There was a relation between serotonin-induced aggregation and the presence of retinopathy. These results suggest that serotonin may be involved in the pathogenesis of diabetic vasculopathy.


Behavioural effects of neonatal metallic mercury exposure in rats.

The effect of neonatal exposure of rats to mercury vapour (Hg0), at the concentration 0.05 mg/m3, 1 h (low dose) or 4 h (high dose), on the behaviour in adulthood were studied. Exposure occurred on days 11-17 (the period of rapid brain growth). Tests for spontaneous motor activity were performed at the ages of 2 and 4 months. Rats exposed to the high dose Hg0 showed a marked increase in variables locomotion and total activity but a decrease for rearing when tested at 2 months of age. At 4 months of age these rats showed a marked hypoactivity with respect to all three variables. Rats exposed to the low dose showed no significant differences at 2 months compared to controls. However, at the age of 4 months the same pattern (increase in variables locomotion and total activity but a decrease for rearing) already noticed in the high dose group at 2 months was observed. In the spatial learning tasks applied, the radial arm maze and circular swim maze, neonatally exposed pups showed a retarded acquisition to the former, while there was no difference compared to controls in the latter. These data indicate that neonatal exposure to mercury vapour results in similar behaviour changes as reported from offspring prenatally exposed to mercury vapour or methylmercury. Furthermore, exposure for 1 week to concentrations around Swedish threshold values (TLV) for 1 or 4 h resulted in dose and age-related behavioural changes.


Investigation of the role of estrogenic action and prostaglandin E2 in DDT-stimulated rat uterine contractions ex vivo.

Previous work in our laboratory showed that o,p'-DDT increases the frequency of rat uterine contractions in vitro. The present study investigated whether this response was related to prostaglandin E2 (PGE2) release from the uterine strips or to the estrogenicity of o,p'-DDT. Contraction frequency was evaluated by recording isometric spontaneous contractions in longitudinal uterine strips from pregnant rats. Assessment of PGE2 levels in the muscle bath showed no significant differences between control and DDT-treated strips, although significant amounts of PGE2 were detected in both groups and increased contraction frequency was observed in o,p'-DDT-treated strips. Furthermore, a role for direct estrogenic action in the medication of o,p'-DDT-stimulated uterine contraction was not supported by the contractility data, because: (i) unlike o,p'-DDT, 17-beta-estradiol had no stimulatory effect, but instead exerted a significant inhibitory effect on uterine contraction; (ii) the estrogen antagonist, tamoxifen, failed to block the stimulatory effect of o,p'-DDT; and (iii) p,p'-DDD, a non-estrogenic DDT analogue, significantly stimulated contraction frequency, similar to o,p'-DDT. These results suggest that the stimulatory effect of o,p'-DDT on contraction frequency is not dependent on PGE2 release or direct estrogen receptor-related action.


Combined exposure to NO2, O3 and H2SO4-aerosol and lung tumor formation in rats.

The promoting effects of a combined exposure to two pollutants (NO2, O3 or H2SO4-aerosol) at near ambient levels on lung tumorigenesis induced by N-bis(2-hydroxypropyl) nitrosamine (BHPN) were investigated in male Wistar rats. The rats were given a single intraperitoneal injection of BHPN (0.5 g per kg body wt.) at 6 weeks of age. They then were exposed to clean air, 0.05 ppm O3 (mean concentration for 10 h/day; 0.1 ppm peak concentration), 0.05 ppm O3 (mean concentration for 10 h/day; 0.1 ppm peak concentration) + 0.4 ppm NO2 or 0.4 ppm NO2 + 1 mg/m3 of H2SO4-aerosol for 13 months and were then maintained in a clean room for another 11 months. Room control animals were kept after injection of BHPN in a clean room for 24 months. The incidence of primary lung tumors in rats exposed to 0.05 ppm O3, 0.05 ppm O3 + 0.4 ppm NO2 and 0.4 ppm NO2 + 1 mg/m3 of H2SO4-aerosol with BHPN treatment was 8.3% (3 out of 36 rats), 13.9% (5 out of 36 rats) and 8.3% (3 out of 36 rats), respectively. The tumors were adenomas and adenocarcinomas. The incidence of adenomas was 2.8% (1 out of 36 rats) in the O3 alone group, 11% (4 out of 36 rats) in O3 + NO2 group and 5.6% (2 out of 36 rats) in NO2 + H2SO4 group. The incidence of adenocarcinomas was 5.6% (2 out of 36 rats) in the O3 group, 2.8% (1 out of 36 rats) in O3 + NO2 group and 2.8% (1 out of 36 rats) in NO2 + H2SO4 group. No lung tumors were found in the rats exposed to clean air with BHPN treatment and in animals not given BHPN but exposed to each air pollutant. The difference in tumor incidence between the clean air group with BHPN and the O3 + NO2 group with BHPN was statistically significant. The results show that exposure to O3 alone enhances tumor development and that the combined exposure to O3 or H2SO4 with NO2 produces an additional increase in incidence of lung tumor, respectively. The incidence of slight-moderate to marked alveolar cell hyperplasia in the groups exposed to each air pollutant with BHPN treatment was higher than that in the groups exposed to clean air with BHPN. Exposure to each air pollutant had no effect on the development of bronchiolar mucosal hyperplasia in lungs of rats treated with BHPN.(ABSTRACT TRUNCATED AT 400 WORDS)


Effect of ICRF-187 on the pulmonary damage induced by hyperoxia in the rat.

Histological and ultrastructural studies were made of the lungs of rats that were exposed to 100% oxygen for 60 h and were treated with either normal saline or with ICRF-187, a bis-diketopiperazine derivative of EDTA that has the capacity to chelate iron. This metal is thought to be needed to catalyze the formation of toxic oxygen free radicals. ICRF-187 (20 mg/kg) was given intraperitoneally at approximately 12 h intervals (5 doses) during the 60 h exposure. Seven of the ten saline-treated rats exposed to oxygen died prior to the end of the study whereas only one of the 10 rats in the ICRF-187-treated group died. This difference in mortality is found to be statistically significant (P less than 0.05). All saline-treated rats showed light and electron microscopic evidence of pulmonary damage. ICRF-187 attenuated the morphologic alterations observed by light microscopy (intra-alveolar edema, inflammatory exudates and bronchiolar epithelial cell swelling and hyperplasia; P less than 0.05). In addition, electron microscopic evaluation revealed that capillary thrombi, endothelial cell alterations and alveolar epithelial cell damage also were less severe in ICRF-187-treated rats. It is concluded that ICRF-187 may provide a new and useful approach for the prevention of hyperoxia-induced pulmonary damage.


Late postnatal growth in the dentate area of the rat hippocampus compensates for volumetric changes caused by early postnatal toluene exposure.

The present report assesses the reversibility of previously described quantitative morphological alterations in the dentate area of the hippocampi of rats exposed to 500 ppm toluene for 12 h daily from postnatal day 1 (P1) to P28. Following the exposure, rats were allowed to survive until P120. The volumes of hippocampal components, as they appear in Timm-stained histological sections, were determined using the Cavalieri estimator. At P120, no differences were apparent in the volumes of the dentate components of control and experimental animals. The differences observed immediately after exposure were eliminated by significantly larger increases in the sizes of early affected components in experimental animals. Different periods of neurogenesis in rodents and primates are briefly discussed as possible confounders of rodent models of permanent toluene-induced morphological alterations in primates.


Dietary glucarate-mediated inhibition of initiation of diethylnitrosamine-induced hepatocarcinogenesis.

Previously, it has been reported that calcium glucarate is a potent inhibitor of chemical carcinogenesis, including phenobarbital-promoted diethylnitrosamine-initiated hepatic toxicity expressed as altered hepatic foci in rats. The purpose of the present study was to determine whether calcium glucarate could inhibit the immediate and delayed appearance of altered hepatic foci when fed to rats during the initiation phase of diethylnitrosamine-induced hepatocarcinogenesis. The effects of dietary mode of administration of calcium glucarate on the initiation phase of hepatocarcinogenesis were also examined. Since diethylnitrosamine is not known to undergo glucuronidation and calcium glucarate has been shown to enhance clearance of circulating estrogens, an indirect mechanism of action of calcium glucarate was also evaluated by pretreating rats with an anti-estrogen, tamoxifen, prior to partial hepatectomy and administration of diethylnitrosamine. Calcium glucarate significantly inhibited both the early and delayed appearance of altered hepatic foci and exerted maximal inhibition when administered by gavage prior to diethylnitrosamine. Maximal inhibition was obtained when calcium glucarate was provided continuously in the diet of animals up to 5 and 7 months. Pretreatment of animals with tamoxifen before partial hepatectomy and diethylnitrosamine resulted in maximal inhibition of the initiation phase of hepatocarcinogenesis. This suggests but does not prove that the anti-carcinogenic activity of calcium glucarate was due to decreased liver proliferation. In the present study, the proliferation of ductular epithelial and oval cells appeared to be associated with the administration of diethylnitrosamine. Collectively, our data suggest that calcium glucarate inhibited the initiation phase of diethylnitrosamine-induced hepatocarcinogenesis.


Benznidazole-induced ultrastructural alterations in rat adrenal cortex. Mechanistic studies.

Benznidazole (Bz) (N-benzyl-2-nitro-1-imidazole acetamide) is a drug used against Chagas' disease, a parasitic disease afflicting several millions of Latin Americans. Bz administration to Sprague-Dawley male rats at 100 mg/kg p.o. caused subcellular alterations in the adrenal cortex involving fasciculata and reticularis zones but not in the glomerulosa. There is Bz nitroreductase activity in the adrenal microsomal and mitochondrial fractions but most of it is localized in mitochondria. Activity in the two fractions requires NADPH under anaerobic conditions. Mitochondrial Bz nitroreductase activity was inhibited by oxygen. A minor but statistically significant inhibition was observed in mixtures incubated under carbon monoxide. Microsomal Bz nitroreductase activity was not detected under oxygen atmosphere and was not inhibited under carbon monoxide. No Bz nitroreductase activity mediated by xanthine oxidase or aldehyde oxidase was detected in the cytosolic fraction from rat adrenals. Electron microscopic examination of the adrenal cortex from Bz-treated animals revealed cells with marked lipid accumulation and alterations in nuclei, endoplasmic reticulum and mitochondria in the reticularis and fasciculata zones. In vitro results suggest a Bz nitroreductive activation, with minor or null P-450 participation, leading to reactive metabolites able to cause damage in various organelles.