Early changes of auditory brain stem evoked response after radiotherapy for nasopharyngeal carcinoma--a prospective study. A prospective study of the effect of radiotherapy for nasopharyngeal carcinoma on hearing was carried out on 49 patients who had pure tone, impedance audiometry and auditory brain stem evoked response (ABR) recordings before, immediately, three, six and 12 months after radiotherapy. Fourteen patients complained of intermittent tinnitus after radiotherapy. We found that 11 initially normal ears of nine patients developed a middle ear effusion, three to six months after radiotherapy. There was mixed sensorineural and conductive hearing impairment after radiotherapy. Persistent impairment of ABR was detected immediately after completion of radiotherapy. The waves I-III and I-V interpeak latency intervals were significantly prolonged one year after radiotherapy. The study shows that radiotherapy for nasopharyngeal carcinoma impairs hearing by acting on the middle ear, the cochlea and the brain stem auditory pathway.


Tragal cartilage inferior turbinate mucoperiosteal sandwich graft technique for repair of nasal septal perforations. Ten cases of large nasal septal perforation were repaired with a tragal cartilage inferior turbinate mucoperiosteal sandwich graft technique with 70 per cent success rate over a follow-up period of up to 24 months. The technique is described in detail. The results are comparable to other techniques.


An apparatus to measure pressure, flow and speech parameters in patients producing speech using the Groningen valve prosthesis. We present a validated method of determining in vivo pressure, flow and voice parameters from patients using tracheo-oesophageal voice prostheses post laryngectomy. This apparatus was constructed simply using equipment which should be available in most large Otolaryngology Departments. There was good agreement between measurements made over two separate sessions of in vivo opening pressure, maximum flow through the device and maximum voice amplitude and these were significant. These measurements may be useful in monitoring patient progress and also in elucidating the mechanics of prosthesis failure.


The use of pyriform sinus mucosa for reconstruction after vertical partial laryngectomy. This prospective study included 30 patients with glottic carcinoma of the larynx who were treated primarily by vertical partial laryngectomy. The pyriform sinus mucosa was used to reconstruct the new laryngeal wall and to form a pseudo-vocal fold at the side of resection. Our results showed that 90 per cent of patients were decannulated, 80 per cent were able to eat a normal diet, 70 per cent developed excellent voice quality after surgery and a 97 per cent three-year survival was achieved. The pyriform sinus mucosa proved to be a reliable material for reconstruction after vertical partial laryngectomy.


New methods of dealing with the complications of panendoscopy. A 70-year-old man with chronic obstructive airways disease was scheduled to undergo panendoscopy following a course of radiotherapy for carcinoma of the larynx. He was anaesthetized using a propofol infusion and high frequency jet ventilation (HFJV). The jet ventilation catheter was left in situ at the end of the procedure. This enabled oxygenation to be maintained in the presence of post-operative laryngospasm by re-attaching the jet ventilator. Subsequently he developed respiratory failure, and a Bullard laryngoscope was used to visualize the vocal folds despite oedema of the tumour which made direct laryngoscopy impossible. A catheter was passed through the biopsy channel of the Bullard, enabling HFJV to be commenced. A conventional endotracheal tube was then railroaded over the catheter to facilitate conventional ventilation.


Osteoma of the internal auditory canal presenting with sudden unilateral hearing loss. A case of an unilateral sensorineural hearing loss of sudden onset, due to an osteoma in the internal auditory canal is presented. As far as the authors are aware an osteoma at this site associated with a hearing loss occurring within a few hours has not previously been reported.


Carcinoma of temporal bone presenting as malignant otitis externa. A 69-year-old man presented with a three-month history of otalgia and tenderness of the right ear and a one-week history of a painful right parotid swelling. Examination revealed granulation tissue in the right ear canal with normal looking tympanic membranes and a parotid abscess. Repeated biopsies from the ear canal and parotid showed non-specific inflammation. Repeated cultures from both areas grew Ps. aeruginosa. The patient's condition improved following three weeks of intensive treatment for malignant otitis externa only to relapse five weeks after the end of treatment. He received a second course, only to improve temporarily. He developed a right facial nerve palsy five weeks after he was first seen, followed four months later by palsies of all cranial nerves except the olfactory, before dying, seven months after his first appointment. The radiological, histological and post-mortem findings are discussed.


Relapsing polychondritis--a study of four cases. Four case reports of relapsing polychondritis, (RP), are presented, together with a literature review and management suggestions. There are approximately 211 reported cases in world literature making RP an uncommon condition associated with high morbidity and mortality rates. The key to the management of RP is based on accurate and early diagnosis though the ideal medical regimen has yet to be elucidated.


External nasal nerve division: a treatment for post-traumatic neuralgia. We present four patients complaining of neuralgic pains across the nasal bridge following trauma, who were successfully treated by division of the external nasal nerve. We believe it is a useful treatment in selected cases.


Dysphagia as a major symptom of tetanus. Dysphagia is a common symptom presenting to ENT departments. Two cases of tetanus with dysphagia as a major symptom are discussed, together with a review of previously reported cases. Although tetanus is a rare disease in the United Kingdom, the possibility of this diagnosis should be borne in mind in patients presenting with progressive dysphagia, especially if there are other head and neck symptoms present.


Perforating injury of the neck and vertebral artery trauma. A 10-year-old schoolboy presented with a penetrating wound to the neck after a children's slide accident. A CT scan and endoscopy showed a traumatic oesophageal-cutaneous fistula. Neurologically the child deteriorated over a period of 34 hours and finally succumbed to a respiratory arrest. Post-mortem findings showed a hypoplastic right vertebral artery. In the left suboccipital triangle a venous clot had blocked the dominant artery thus leading to cerebellar and brainstem infarction. This extraluminal compression leading to obstruction of an otherwise non traumatized vertebral artery is unique in the literature.


Tuberculosis of the parotid gland: clinically indistinguishable from a neoplasm. Tuberculosis of the parotid gland may be clinically indistinguishable from a neoplasm. This poses a problem with regard to management, because the treatment of tuberculosis is medical, whilst that of the majority of tumours is surgical. If radical surgery with resection of a branch or branches of the facial nerve is embarked upon in a patient with tuberculosis, without prior histological diagnosis, unnecessary permanent disability will result. Two cases of tuberculosis of the parotid gland are reported, demonstrating the clinical similarity of tuberculosis to a parotid neoplasm and the absolute need for histological diagnosis before embarking on surgery that will require resection of the branches of the facial nerve. The conclusion is that although tuberculosis of the parotid gland is rare, it still exists and must be thought of as one of the differential diagnoses of a parotid tumour. This must be kept in mind, especially when the decision to sacrifice branches of the facial nerve is indicated, in order to get a tumour-free margin on an excisional biopsy. If the suspicion of tuberculosis is high, a therapeutic trial of antituberculous chemotherapy, for one week, can be diagnostic.


A long-standing cystic lymph node metastasis from occult thyroid carcinoma--report of a case. The authors describe a patient with a cervical cystic mass present for 14 years which proved to be a cystic metastasis from a papillary carcinoma of the thyroid gland. This is probably the first case report of a long-term lateral cervical cyst caused by an occult thyroid carcinoma.


Immunohistochemical identification of androgen receptors in germ cell neoplasia. The highest prevalence of testicular cancer occurs in young men with high androgen activity. The presence and distribution of androgen receptors (ARs) was therefore investigated in germ cell neoplasia, using two specific monoclonal antibodies. Tissue samples from 18 patients with seminoma and/or carcinoma-in-situ (CIS) of the testis were examined. An indirect immunohistochemical method with a biotin-streptavidin-peroxidase or an alkaline phosphatase detection system was used. 45% of seminoma samples and 42% of CIS samples were AR-positive with antibody AN 1-15. The values obtained using antibody F 39.4.1 were 44 and 40% respectively. Some differences in specificity between the two antibodies were observed. Unusual granular staining of germ cells in normal testes, also present in malignant germ cells, was noted when antibody F39.4.1 was used. The presence of AR protein immunoreactivity in neoplastic germ cells suggests that androgens may be involved in the pathogenesis of the disease.


Direct stimulation of bovine ovarian progesterone secretion by low concentrations of alpha-interferon. The ruminant conceptus secretes proteins during early pregnancy which maintain the corpus luteum. These trophoblast proteins are related to the alpha II-interferons and prevent luteolysis indirectly by disrupting the secretion of endometrial prostaglandin. Although trophoblast interferons appear to be largely confined to the uterine lumen, it remains possible that they also act peripherally. This report describes in vitro studies which suggest that interferon may influence hormone secretion by the ovary directly. The study employed i) a well defined serum-free culture model in which bovine granulosa cells secrete the luteal hormones progesterone and oxytocin, and ii) serum-free and serum-supplemented cultures of cells from early CL. Dose-response experiments were performed using bovine recombinant alpha-interferon (brIFN). Progesterone and oxytocin secretions were measured over 4-5 days of culture and DNA content was also determined. Low concentrations of brIFN (10(-15) mol/l to 10(-11) mol/l) stimulated progesterone secretion by granulosa cells by up to three fold, without significantly affecting oxytocin concentrations or culture DNA content. Concentrations of 10(-10) mol/l to 10(-1) mol/l suppressed progesterone secretion in a log dose-related manner (r = 0.97) with evidence of toxicity (lower oxytocin concentrations and significantly reduced DNA compared with controls). Progesterone secretion by luteal cells in serum-free culture was stimulated in the presence of 10(-15) mol/l brIFN, whilst high concentrations again caused inhibition. The data show that ovarian cells can respond directly to low concentrations of interferon-like proteins.(ABSTRACT TRUNCATED AT 250 WORDS)


The role of growth hormone, prolactin and insulin-like growth factors in the regulation of rat mammary gland and adipose tissue metabolism during lactation. Inhibition of prolactin secretion with bromocriptine and neutralization of GH action with a specific antiserum to rat GH (rGH) were used to explore the modes of action of GH and prolactin in maintaining lactation in the rat. Treatment of dams with anti-rGH caused a small reduction in litter weight gain whilst bromocriptine reduced litter weight gain by 50%. When both treatments were combined, however, milk yield ceased completely and this was accompanied by a wide variety of effects on mammary lipid metabolism including decreases in the mRNA concentrations of acetyl CoA carboxylase, fatty acid synthase, malic enzyme and lipoprotein lipase. Activities of acetyl CoA carboxylase and lipoprotein lipase were also significantly reduced. Reciprocal changes were evident in adipose tissue with increases in acetyl CoA carboxylase and lipoprotein lipase activities. In conjunction with a decreased lipolytic response to noradrenaline in adipose tissue of animals given the combined treatment of bromocriptine and anti-rGH, this represented a co-ordinated series of changes to reduce lipid synthesis in the mammary gland and enhance lipogenesis and triglyceride storage in adipose tissue as milk production ceased. All of these effects could be prevented in part by concurrent treatment with GH, but insulin-like growth factor-I (IGF-I) and IGF-II failed to affect any of the parameters measured.(ABSTRACT TRUNCATED AT 250 WORDS)


In-vivo regulation of messenger RNA encoding insulin-like growth factor-I (IGF-I) and its receptor by diabetes, insulin and IGF-I in rat muscle. The effects of continuous or acute administration of insulin or insulin-like growth factor-I (IGF-I) on IGF-I mRNA and IGF-I receptor mRNA were studied in the skeletal muscle (gastrocnemius), heart muscle and vascular smooth muscle (aorta) of non-diabetic and diabetic rats using a solution hybridization assay. The levels of IGF-I mRNA in the different types of muscle markedly decreased by diabetes, whereas changes in IGF-I receptor mRNA were less consistent. Continuous infusion of diabetic rats with insulin (28 or 35 nmol/day) for 4 days normalized the altered levels of IGF-I mRNA and IGF-1 receptor mRNA. Infusion of equimolar concentrations of IGF-I did not affect IGF-I mRNA, but decreased the level of IGF-I receptor mRNA in skeletal muscle. In acute experiments, rats were injected with equipotent blood glucose-lowering doses of insulin (14 nmol) or IGF-I (107 nmol). Insulin did not significantly affect levels of IGF-I mRNA, but decreased levels of IGF-I receptor mRNA in skeletal muscle and aorta. IGF-I increased levels of IGF-I mRNA in heart muscle, and markedly decreased levels of IGF-I receptor mRNA in skeletal muscle and heart muscle from non-diabetic and diabetic rats. In conclusion, exogenous IGF-I and insulin can increase IGF-I mRNA and decrease IGF-I receptor mRNA, indicating that both insulin and IGF-I can act as regulators of the IGF-I system in muscle in vivo.


Effects of insulin, glucocorticoids and thyroid hormones on the activities of key enzymes of glycolysis, glutaminolysis, the pentose-phosphate pathway and the Krebs cycle in rat macrophages. In the present study the effects of insulin, glucocorticoids and thyroid hormones on macrophage metabolism and function were investigated. The maximum activities of hexokinase, glucose-6-phosphate dehydrogenase, glutaminase and citrate synthase were determined in macrophages obtained from hormone-treated rats and those cultured for a period of 48 h in the presence of hormones. Macrophage phagocytosis was markedly inhibited by dexamethasone and thyroid hormones, remaining unchanged when insulin was added to the culture medium, however. The changes in the enzyme activities caused by hormone treatments of the rats were very similar to those found in culture. Insulin enhanced citrate synthase and hexokinase activities and diminished those of glutaminase and glucose-6-phosphate dehydrogenase. Dexamethasone had a similar effect except on glucose-6-phosphate dehydrogenase. The addition of thyroid hormones to the culture medium raised the activities of glutaminase and hexokinase and reduced that of citrate synthase. The results presented support the suggestion that the effects of insulin, glucocorticoids and thyroid hormones on immune and inflammatory responses could well be mediated through changes in macrophage metabolism.


Gonadotrophin surge-attenuating factor attenuates in-vitro LH secretion induced by gonadotrophin-releasing hormone from cultured ovine pituitary cells only during the breeding season. Primary cultures of ovine pituitaries from adult ewes were used to investigate aspects of gonadotrophin surge-attenuating factor (GnSAF) bioactivity in human follicular fluid (hFF) from superovulated women. During the autumn and first half of the winter, LH secretion induced by gonadotrophin-releasing hormone (GnRH) was markedly reduced (43.5 +/- 5.2% of control GnRH-induced LH secretion) by incubation for 48 h with steroid-free hFF. For the rest of the year, treatment with the same batch of steroid-free hFF resulted in non-significant reduction or stimulation of GnRH-induced LH secretion (71.3 +/- 13.2 to 117.8 +/- 11.2% of control GnRH-induced LH secretion). Incubation of pituitary cells for 48 h with oestradiol (1 pmol/l to 1 mumol/l), progesterone (1 pmol/l to 1 mumol/l) or oestradiol and progesterone combined (1 pmol/l to 1 mumol/l) in a two-way titration for 48 h had no significant effect on GnRH-induced LH secretion (83.4 +/- 7.6 to 110.6 +/- 5.0% of control secretion). Separating hFF into fractions of different molecular mass by ultrafiltration demonstrated that GnSAF bioactivity was present in a form 10-30 kDa in size. Incubation for 48 h with these fractions had no significant effect on basal FSH secretion but significantly attenuated GnRH-induced LH secretion during the autumn. The same fractions had little effect on GnRH-induced LH secretion from pituitary cells collected during the summer. We conclude that ovine pituitaries display at least partial reduction in sensitivity to GnSAF outside the breeding season.(ABSTRACT TRUNCATED AT 250 WORDS)


Antiuterotrophic effects of a pure antioestrogen, ICI 182,780: magnetic resonance imaging of the uterus in ovariectomized monkeys. ICI 182,780 is a potent specific pure antioestrogen which may offer advantages in breast cancer treatment compared with partial agonists like tamoxifen. To characterize further the potency and efficacy of ICI 182,780, its effects on the uterus of ovariectomized, oestrogen-treated monkeys (Macaca nemestrina) have been measured using magnetic resonance imaging (MRI). Quantitative MRI allows accurate non-invasive repetitive measurements of endometrial and myometrial volume following hormonal treatments, using each animal as its own control. Single i.m. injections of a long-acting oil-based formulation of ICI 182,780 sustained blockade of oestradiol action on the monkey uterus in a dose-dependent manner for 3-6 weeks. Repeated injections of 4 mg ICI 182,780/kg at 4-weekly intervals provided increasingly effective blockade of uterine proliferation. In a short-acting formulation, ICI 182,780 also completely blocked the trophic action of oestradiol, administered concurrently, in ovariectomized monkeys. Similarly, ICI 182,780 caused involution of the uterus stimulated by prior treatment with oestradiol. The rate and extent of uterine involution in monkeys treated with ICI 182,780 was similar to that seen following oestrogen withdrawal. These studies demonstrate that ICI 182,780 is a fully effective pure antioestrogen in a primate.


Ectopic transcription of the parathyroid hormone gene in lymphocytes, lymphoblastoid cells and tumour tissue. Using reverse transcription polymerase chain reaction, steady-state levels of parathyroid hormone (PTH) mRNA were investigated in a number of human, bovine and rat tissues. Transcripts were consistently detected in parathyroid glands as well as in lymphocytes, lymphoblastoid cells and several tumours. Levels of transcription were not measurably increased in lymphoblastoid cells and tumour tissues compared with unstimulated peripheral lymphocytes. The level of 'ectopic' transcription of the PTH gene in lymphoblastoid cells appeared to be resistant to the administration of both vitamin D and phorbol esters.


The role of thromboxane in the uterotrophic response in the gravid normotensive and spontaneously hypertensive rat. The role of thromboxane in the gravid normotensive (CD) and hypertensive (SHR) rat was investigated (by utilizing two thromboxane receptor-blocking drugs, EP092 and AH23848) both at mid-gestation and at term. The parameters examined were uterine blood flow (blood flows were measured by the microsphere technique) and uterine weight and placental blood flow at term, fetal mass and number. At mid-gestation EP092 significantly (P < 0.005) increased uterine blood flow in both strains whilst the increases seen with AH23848 were not statistically significant. At term (day 22 in the CD and day 23 in the SHR rat) the antagonists increased uterine blood flow in the CD rats alone. However, at this time the antagonists caused an increase in placental blood flow in both strains. Thromboxane appears to be involved in the regulation of uteroplacental blood flow. The observation that the antagonists were able to potentiate blood flow by mid-gestation may provide a clinical indication with respect to potential prophylactic use of this class of compounds in cases of pregnancy-induced hypertension in women.


A comparison of the uterotrophic response in cyclic and ovariectomized normotensive and spontaneously hypertensive rats. The uterotrophic response in the normotensive (CD) and the hypertensive (SHR) rat was compared in intact cyclic rats and in ovariectomized rats given oestradiol. The parameters measured were blood flow, and uterine wet and dry weights. In the cyclic animals blood flow to the oestogen target tissue varied throughout the oestrous cycle, peak flows being achieved at pro-oestrus; in the SHR rat, however, the pro-oestrous maximum was significantly attenuated compared with the CD rat. Uterine wet and dry weights were similar. The temporal response to oestradiol in ovariectomized rats showed that in the CD rat the hyperaemic response peaked earlier than in the SHR rat, significant changes in terms of increased water imbibition also occurred more quickly in the CD strain. In both strains, uterine dry weight was the last parameter to be significantly increased, the maximum weight being attained more quickly in the SHR rat. The results of this study indicated that it is the blood flow to the oestrogen target tissues of the uterus and vagina that is most susceptible to change with strain of rat.


Fine structure of adrenal cortex in rats harbouring a medullary thyroid carcinoma transfected with a corticotrophin-releasing hormone cDNA expression vector. We report the light microscopic, transmission and scanning electron microscopic features of the adrenal cortices in rats bearing a medullary thyroid carcinoma cell line transfected with a corticotrophin-releasing hormone (CRH) cDNA expression vector. The animals had elevated CRH, ACTH and corticosterone blood levels, involuted thymuses and markedly enlarged adrenal glands with prominent lipid-depleted cortices and dilated congested capillaries, similar to those of animals treated with ACTH. Using electron microscopy it was found that the enlarged fasciculata and reticularis zones were composed of large, compact cells with abundant smooth endoplasmic reticulum, prominent Golgi complexes, increased number of large mitochondria with focal loss of cristae and cavitation of the internal compartments, numerous lysosomes and prominent elongated microvilli. In addition, small cytoplasmic fragments were seen within the capillary lumina; these structures resembled microvilli that were apparently detached from adrenocortical cells and entered the blood stream via discontinuous endothelium of dilated capillaries. By scanning electron microscopy it was found that the cells had bulging surfaces with scattered pits and numerous long microvilli pointing in different directions. This animal model allows analysis of the effects of protracted CRH excess resembling tumoural CRH-dependent Cushing's syndrome in human patients. Our findings call attention to the role of microvilli in adrenocortical secretion. The increased number and size of microvilli has been thought to lead to an increase in the surface area of adrenocortical cells, thereby facilitating hormone discharge. The detachment of microvilli from adrenocortical cells may represent a form of apocrine secretion and may contribute to hypercorticosteronaemia in CRH excess.


Passive immunization against circulating insulin-like growth factor-I (IGF-I) increases protein catabolism in lambs: evidence for a physiological role for circulating IGF-I. Primed constant infusions of [14C]urea were used to determine the acute effect of passive immunization against circulating free and protein-bound insulin-like growth factor-I (IGF-I) on the rate of net protein catabolism (NPC) in castrated male lambs fasted for 48 h. Following an intravenous bolus of 50 ml IGF-I antiserum, the rate of NPC increased to a peak 30 min after injection of 1.69 +/- 0.16 g/kg per day from a baseline value of 1.45 +/- 0.22 g/kg per day (P < 0.05, n = 4). In three animals given 50 ml equivalents of the purified immunoglobulin fraction, NPC increased from 1.31 +/- 0.20 to 1.59 +/- 0.16 g/kg per day (P < 0.05). A similar trend was observed in animals given 25 ml antiserum (n = 4). The rate of NPC did not increase following a bolus of non-immune serum in control animals and the rate of NPC in the treated lambs returned to control levels within 60 min of antibody injection. Plasma insulin and glucose concentrations in both the treated and control groups were unchanged throughout the study. These data suggest that circulating IGF-I has a physiological role in regulating whole body protein turnover during starvation and possibly other catabolic states. The effect of immunoneutralization of circulating IGF-I is transient and this suggests that while IGF-I has an endocrine role in the regulation of protein turnover, other regulatory mechanisms are involved.


Zona radiata proteins are synthesized by rainbow trout (Oncorhynchus mykiss) hepatocytes in response to oestradiol-17 beta. The present study delineates the origin of the three major proteins constituting the rainbow trout (Oncorhynchus mykiss) zona radiata. Intraperitoneal administration of oestradiol-17 beta induced the appearance in the blood from juvenile fish (both sexes) of proteins immunoreactive to rabbit antisera against zona radiata proteins (zr proteins). These proteins had similar molecular weights to the zr proteins (alpha, 60 kDa; beta, 55 kDa; and gamma, 50 kDa). Primary hepatocyte cultures from fish treated with oestradiol-17 beta incorporated radioactive [35S] methionine into four major proteins with molecular weights of 160, 60, 55 and 50 kDa. Only the latter three proteins were specifically immunoprecipitated with antibodies to zr proteins. Furthermore, our data demonstrate that in such cultures the biosynthetic mole ratios of these secreted proteins (60, 55 and 50 kDa) are close to one. Control cultures from fish that had not been treated with oestradiol-17 beta failed to produce immunoreactive proteins. The data support the hypothesis that zr proteins are synthesized in a concerted manner in the liver during teleostean oogenesis and transported by the blood for deposition in ovarian follicles.


Immunochemical detection of the major vitelline envelope proteins in the plasma and oocytes of the maturing female rainbow trout, Oncorhynchus mykiss. The major vitelline envelope proteins were detected in the plasma of female rainbow trout maturing under natural conditions by using the Western blot technique. Females were sampled every month from July until ovulation in January. The amount of vitelline envelope proteins in plasma increased markedly as the gonads increased in size from 0.4 to about 15% of the total body weight. The plasma level of oestradiol-17 beta largely followed the alterations in the amount of vitelline envelope proteins, indicating the endocrine control of vitelline envelope protein synthesis. In addition, plasma vitellogenin changed in a manner that resembled the changes in the amount of plasma vitelline envelope proteins. The appearance and growth of the vitelline envelope during oocyte development was demonstrated using immunohistochemical methods. The vitelline envelopes from oocytes at different stages of development were immunoreactive with the antibodies directed against the major vitelline envelope proteins. No immunoreactivity could be observed in the ooplasm or in the surrounding follicular cells, which indicated that the major vitelline envelope proteins were of extraovarian origin. The present study further supports the hypothesis that the major protein constituents of the vitelline envelope in teleosts are under the endocrine control of oestradiol-17 beta and that the site of synthesis is outside the ovary.


Milking frequency alters the milk yield and mammary blood flow response to intra-mammary infusion of insulin-like growth factor-I in the goat. The milk yield and mammary blood flow responses to close-arterial, intra-mammary infusion of IGF-I were investigated in five Saanen goats milked frequently or normally the day before. Animals were infused for 6 h with recombinant human IGF-I (1.3 nmol/min) and milked hourly following i.v. injection of oxytocin beginning 2 h before infusion and then every 2 h. On one occasion animals were milked five times (after i.v. injection of oxytocin) on the day before infusion and on the other they were milked twice, without oxytocin. The ratio of milk yield from the infused to that from non-infused gland increased by 17 +/- 4% (mean +/- S.E.M.) in goats milked twice the day before infusion and by 6 +/- 2% when the infusion was preceded by frequent milking. Maximal responses were obtained 4 h after the start of the infusion and differed significantly (P < 0.05), according to pretreatment milking. Blood flow through the infused gland rose in parallel to the milk yield response. At 5 h, when maximal levels were achieved, blood flow was 182 +/- 23% of the pre-infusion flow rate following twice-daily milking and 139 +/- 3% of the pre-infusion flow rate following more frequent milk removal. Thus, more frequent milk removal on the day before close-arterial infusion of IGF-I attenuated both the milk yield and mammary blood-flow response to the infusion of IGF-I.


Different molecular forms of C-type natriuretic peptide isolated from the brain and heart of an elasmobranch, Triakis scyllia. The presence of a C-type natriuretic peptide (CNP) has been reported in the brain of mammals, birds, amphibians and teleost fishes, mostly as a 22-residue peptide (CNP-22). In the present study, we attempted to isolate natriuretic peptides from an elasmobranch, Triakis scyllia, using a chick rectum-relaxant assay, and different molecular forms of CNP were found in the brain and heart. Only CNP-22 was recovered from the brain, as is the case in other vertebrates. A large amount of prohormone (proCNP or CNP-115) and small amounts of its C-terminal peptides (CNP-38 and CNP-39) were isolated from the atrium and ventricle, however. No CNP-22 was recovered from the heart. Natriuretic peptides other than CNP were not isolated from Triakis heart and brain by the rectum-relaxant assay. The 22 residues at the C-terminal region of proCNP, i.e. CNP-22, were well conserved when Triakis and mammals were compared, although the sequence homology of the N-terminal segment of proCNP was very low. Not only was CNP-22 identical but the N-terminal segments of proCNP were also quite similar when Triakis and another elasmobranch, Scyliorhinus canicula, were compared. These data suggest that, in elasmobranchs, CNP is a primary hormone in the natriuretic peptide family, and also that CNP is processed differently in the brain and heart.


Atrial natriuretic peptide in eel plasma, heart and brain characterized by homologous radioimmunoassay. A highly specific and sensitive radioimmunoassay has been developed for the measurement of eel atrial natriuretic peptide (ANP). The antiserum, raised against eel ANP-(1-27) did not cross-react with two other eel natriuretic peptides, i.e. eel ventricular natriuretic peptide and C-type natriuretic peptide (CNP), or with any mammalian ANPs, CNPs or brain natriuretic peptides so far identified. The minimal detectable amount was 0.39 fmol (0.90 pg)/tube with more than 99% confidence. Because of its high sensitivity, the radioimmunoassay makes it possible to measure eel ANP directly with only a few microlitres of plasma without extraction. Using the radioimmunoassay we found high levels of ANP in the atrium (11 +/- 2 pmol/mg wet tissue, n = 8), and much lower levels in the ventricle (56 +/- 8 fmol/mg, n = 8) and the brain (22 +/- 1 fmol/mg, n = 8) of eels. Eel plasma contained a large amount of ANP (247 +/- 66 fmol/ml, n = 8) compared with the levels reported in mammals, although atrial levels are similar between eels and mammals. Gel-permeation chromography revealed that a major form of ANP stored in the eel atrium, ventricle and brain has a molecular mass of approximately 14 kDa but low molecular forms of about 3 kDa are predominant in eel plasma. A detailed analysis with reverse-phase high-performance liquid chromatography showed that a major molecular form circulating in eel plasma is ANP-(1-27). ANP-(1-27) was also detected in small amounts in the eel atrium, ventricle and brain.


A polyclonal antibody to the rat oestrogen receptor expressed in Escherichia coli: characterization and application to immunohistochemistry. A rat oestrogen receptor-beta-galactosidase fusion protein was expressed using a pEX2/rat oestrogen receptor cDNA construct. Scatchard analysis of [3H]oestradiol-17 beta binding to the cell lysate revealed that the fusion protein had functional binding sites specific for oestradiol with a dissociation constant of 1.49 nmol/l. The relative molecular weight (M(r)) of the fusion protein was determined as 180,000 by immunoblot analysis of the cell lysate employing a monoclonal antibody to the human oestrogen receptor. The protein was isolated by means of SDS-PAGE and subsequent electroblotting. By immunization with the purified materials on nitrocellulose membrane, a polyclonal antibody to the rat oestrogen receptor was raised in a rabbit. Binding of [3H]oestradiol to the oestrogen receptor from the rat uterus was inhibited by the antibody in a dose-dependent manner. The antibody was also able to recognize the oestrogen receptor occupied by [3H]oestradiol. Thus, the antibody could react with both forms of the receptor molecule, either occupied or unoccupied by the hormone. In immunoblot analysis of the cytosol fraction of the rat uterus, a single band of M(r) 67,000, the size of the oestrogen receptor, was detected by the antibody. Moreover, when the antibody was applied to immunohistochemical examination of paraffin-embedded pituitary and brain sections of the rat, immunostaining was observed in cells of the anterior pituitary and in neurones in specific regions of the brain. The immunoreactivity was restricted exclusively to cell nuclei in both tissues.(ABSTRACT TRUNCATED AT 250 WORDS)


The identification and characterization of 125I-labelled iodomelatonin-binding sites in the duck kidney. The melatonin-binding sites in membrane preparations of duck kidney were demonstrated by utilizing 125I-labelled iodomelatonin as a radioligand. Binding at these sites was found to be reversible, saturable, specific and of high affinity. Scatchard analysis of the specific binding revealed an equilibrium binding constant (Kd) of 44.6 +/- 4.4 pmol/l (n = 6) and a total number of binding sites (Bmax) of 6.43 +/- 0.60 fmol/mg protein (n = 6) at the mid-point of the light period (mid-light). The Hill coefficient approached 1.0, suggesting a single class of 125I-labelled iodomelatonin-binding site in the duck kidney. Diurnal variation in 125I-labelled iodomelatonin binding showed that the Bmax was 53.4% higher at mid-light than at mid-point of the dark period (P < 0.05), with no significant variation in Kd. The Kd value determined from kinetic analysis was 22.5 pmol/l in birds at mid-light, which was comparable with values determined from equilibrium studies. The order of pharmacological affinity for 125I-labelled iodomelatonin-binding sites in the duck kidney membrane preparations was: 2-iodomelatonin > melatonin > 6-chloromelatonin > 6-hydroxymelatonin > N-acetylserotonin >> 5-methoxytryptamine, 5-methoxytryptophol, 5-hydroxytryptamine, tryptamine, 1-acetylindole-3-carboxaldehyde, 5-hydroxyindole-3-acetic acid, L-tryptophan, 5-methoxyindole-3-acetic acid, 3-acetylindole, acetylcholine, epinephrine, norepinephrine and harmaline. The pharmacological characteristics indicated that 125I-labelled iodomelatonin-binding sites are highly specific for melatonin. Our finding of 125I-labelled iodomelatonin-binding sites in the kidney suggests that melatonin may regulate kidney function.(ABSTRACT TRUNCATED AT 250 WORDS)


Restoration of juvenile baseline growth hormone secretion with preservation of the ultradian growth hormone rhythm by continuous delivery of growth hormone-releasing factor. The ability of continuously delivered GH-releasing factor (GRF) to enhance GH secretion while maintaining the normal ultradian GH rhythm was investigated. Synthetic human GH-releasing factor (hGRF(1-44)NH2) was continuously infused for 4 days by means of i.v. catheters to 11-week-old broiler chickens. At this age, overall endogenous GH secretion is low, and baseline GH is barely detectable. Six birds per treatment received vehicle (control), 0.324 mg hGRF(1-44)NH2/kg body weight per day (low dose) or 3.24 mg hGRF(1-44)NH2/kg body weight per day (high dose). After 4 days of GRF conditioning, concurrent with continued GRF infusion, serial blood samples were removed via atrial catheters at 15-min intervals for 6 h and GH plasma profiles determined. High dose GRF significantly increased GH plasma concentrations over tenfold compared with controls; however, most of this increase reflected an increase in basal GH, which was reinstated to juvenile baseline levels. Augmentation of pulse amplitude above this increased baseline was not proportionately as high, and failed to reach juvenile levels. The ultradian rhythm of GH was not altered by continuous GRF administration. Both low and high dose GRF treatments resulted in significant enlargement of the anterior pituitary gland. Total pituitary GH mRNA levels, although elevated over twofold by GRF treatment, were not significantly different from controls. Measures of plasma GH magnitude (overall and baseline mean, and peak amplitude) were significantly correlated with pituitary GH mRNA for control birds, but were not correlated for GRF treatments. Feed intake was markedly depressed (33%) on the high dose GRF treatment, in conjunction with total inhibition of body weight gain over the 4-day period of administration. Longitudinal bone growth and width of the epiphyseal growth plate were also significantly reduced by high dose GRF treatment, probably reflecting the reduced level of nutrient intake, despite high circulating concentrations of GH.


Activation of phospholipase A2 and phospholipase C by endothelin-1 in human endometrium. Human endometrium contains specific binding sites for iodinated endothelin (ET)-1, ET-2 and ET-3, and ET-1 stimulates prostaglandin (PG) F2 alpha synthesis from explants of proliferative endometrium in short-term culture. This study has investigated the cellular responses of normal proliferative endometrium to ET-1. Radioimmunoassay was used to measure PG release and Dowex anion-exchange column chromatography was utilized to assess the accumulation of inositol phosphates. Endothelin-1 induced a significant increase in PGF2 alpha release (basal median: 1465 pg/mg per 60 min (range: 541-3935 pg/mg per 60 min); ET-1-stimulated: 1813 pg/mg per 60 min (1021-5714 pg/mg per 60 min); P < 0.04 using Wilcoxon signed rank test). The effect of ET-1 was attenuated in the presence of the phospholipase A2 inhibitor quinacrine. Endothelin-1 induced a rapid, transient and concentration-dependent hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2), measured by the accumulation of tritiated inositol phosphates. Following a 1-min stimulation with ET-1 (100 nmol/l), [3H]inositol mono-, bis- and trisphosphate fractions increased from median values of 490.0 d.p.m./mg dry wt (range: 348.0-807.0 d.p.m./mg dry wt), 120.0 d.p.m./mg dry wt (93.6-144.1 d.p.m./mg dry wt) and 67.0 d.p.m./mg dry wt (54.2-85.0 d.p.m./mg dry wt) to 939.0 d.p.m./mg dry wt (635.9-1596.0 d.p.m./mg dry wt; P < 0.03), 145.0 d.p.m./mg dry wt (127.0-293.9 d.p.m./mg dry wt; P < 0.05) and 146.0 d.p.m./mg dry wt (77.5-187.0 d.p.m./mg dry wt; P < 0.03) respectively. These results suggest that ET-1 activates the phospholipase A2 and PtdIns(4,5)P2-specific phospholipase C in human proliferative endometrium, resulting in the generation of PGF2 alpha and second messengers respectively which are pivotal to endometrial function.


Physical fitness or physical activity as a predictor of ischaemic heart disease? A 17-year follow-up in the Copenhagen Male Study. Physical fitness and leisure time physical activity are strongly correlated, and both are inversely correlated with risk of ischaemic heart disease. Does this mean, however, that a very fit man has a lower risk of ischaemic heart disease (IHD), even if he is inactive? And does it also mean that an unfit, but active man, does not have a lower risk of IHD than an unfit, inactive man? In the Copenhagen Male Study, we analysed the joint effect of fitness and leisure time activity. In 1970/71, 4999 men aged 40-59 years, were classified according to level of physical fitness, i.e. indirectly measured maximal oxygen uptake, and physical activity, and their mortality was recorded over the following 17 years. In sedentary men, fitness was no predictor of future risk of IHD whatsoever. Age-adjusted baseline values were similar in later IHD cases and survivors (32.3 and 32.1 ml O2 kg-1 min-1, respectively: P = 0.91). In medium or highly active men, however, fitness was a strong predictor. The corresponding fitness values were 33.1 and 34.8 ml O2 kg-1 min-1 (P < 0.001). The least fit (two least fit quintiles) physically active men had a lower IHD mortality rate (6%) than the least fit sedentary men (10%). Adjusted for age, social class and smoking in a multiple logistic regression equation, this was estimated to an RR (95% C.I.) of 1.67 (1.06-2.64) (P = 0.027). The two major new findings of this study were (a) that being very fit, provides no protection against IHD--nor all-cause mortality--in sedentary men, and (b) that unfit but sedentary men have a higher risk of IHD than unfit but active men, i.e. those performing light physical activity for at least 4 h per week.


The Lewis blood group--a new genetic marker of ischaemic heart disease. In a cohort of 3383 men aged 53 to 74 in the Copenhagen Male Study we investigated the association between ischaemic heart disease (IHD) and the Lewis blood group, assigned to chromosome 19. Among men with the Le(a-b-) phenotype, 8% had a history of non-fatal myocardial infarction, among others the frequency was 4%. The corresponding odds ratio was (95% confidence interval: CI) 1.9 (1.2-3.0) P < 0.01, men with Le(a-b-) had a risk-factor profile and pattern of disease resembling that of Reaven's syndrome X. In a subsequent prospective study 343 men with arteriosclerotic stigmas were excluded. The men had their morbidity and mortality recorded over the next 4 years. One-hundred-and-one men suffered IHD; 26 dying from IHD. In total 162 men died. Men with Le(a-b-) had an increased risk of death from IHD compared with others. Adjusted for age, relative risk (RR) (95% CI) was: 4.4 (1.9-10.3), P < 0.001, and for all causes of mortality: RR = 1.6 (1.0-2.6), P < 0.05. Men with the Le(a-b-) phenotype had an increased risk of an IHD event compared to men with other phenotypes (RR = 1.6 (0.9-2.8), P = 0.10) and a significantly higher IHD case fatality rate (RR = 2.8 (1.5-5.2), P = 0.01). The finding that the Le(a-b-) phenotype is a genetic marker of IHD risk may have implications in terms of prevention. The Le(a-b-) phenotype may also contribute to providing an explanation for the substantial ethnic differences found in the incidence of IHD. The similar risk-factor profile and pattern of disease found between Le(a-b-) men and individuals with Reaven's syndrome X is hypothesized to be due to a close genetic relationship on chromosome 19.


Effects of amlodipine on plasma lipid and lipoprotein levels in hypertensive patients. Lipids and lipoprotein levels were determined in the plasma of 20 adult hypertensive patients, after 12 weeks treatment with amlodipine. No significant variation was observed in the mean values of the lipids and lipoprotein fractions before and after amlodipine treatment for the patients on either 5 mg or 10 mg of amlodipine. A further long-term study has been suggested in order to confirm the inertness of amlodipine on lipids and lipoprotein metabolism.


Deterioration in renal function associated with angiotensin converting enzyme inhibitor therapy is not always reversible. Fifteen patients presented between January 1986 and January 1991 with deterioration in renal function coincident with the introduction of angiotensin converting enzyme inhibitors. There was evidence of extrarenal vascular disease in 12 patients and preexisting renal impairment in 13. Four patients remained dialysis-dependent and died within 4 weeks of presentation. Five patients required short-term dialysis. Serum creatinine remained above pre-treatment values in seven patients. Conventional explanations of the decline in renal function with ACE inhibition do not account for irreversible decrements in renal function. Possible mechanisms for this observation and clinical guidelines to identify patients at risk are suggested. We conclude that these agents should be used with great care in patients in whom atherosclerotic vascular disease is likely.


The prevalence of hypertrophic cardiomyopathy in men: an echocardiographic population screening study with a review of death records. The purpose of this study was to estimate the prevalence of hypertrophic cardiomyopathy (HCM) in 3607 men from the Reykjavik study of 1979-81. Of these, 452 men had an abnormal (group A) and 3155 a normal electrocardiogram. An echocardiographic control group of 128 men was selected from cohorts with a normal electrocardiogram (group B). Until 1987, 189 deaths had occurred, 59 from group A and 130 from cohorts with a normal ECG including 4 from group B. To identify subjects with HCM, survivors of groups A and B were examined by echocardiography and by review of all autopsy data and death certificates. HCM was found in 14 subjects from group A but none in group B. Two additional cases were found at autopsy in cohorts with a normal ECG. The prevalence of HCM in men with an abnormal and normal ECG was 3.6% and 0.8%, respectively. The overall prevalence was calculated to be 1.1% with a 95% confidence interval of 0.3-3.2%. Men with HCM reported more symptoms than others in groups A and B (P < 0.05-0.001). 25% were without symptoms. Asymptomatic ventricular arrhythmias were detected by Holter monitoring in 45% of men with HCM. The total annual mortality was 1.6% compared with 0.5% in the group with a normal ECG (P < 0.001).


Hypercalcaemia in Addison's disease: calciotropic hormone profile and bone histology. Three cases of hypercalcaemia secondary to acute adrenocortical insufficiency are described; all the patients had moderate to severe renal impairment, one being on chronic dialysis treatment with no residual diuresis. Parathyroid hormone (PTH) and 1,25 dihydroxyvitamin D [1,25(OH)2D] were low, indicating a suppressed PTH-vitamin D axis. In the two patients with partial renal impairment, urine Ca excretion was increased, indicating increased load of the cation into the extracellular fluid (ECF), most probably from bone. Saline infusion, to correct any ECF depletion and to increase urine Ca excretion, could not fully correct the hypercalcaemia. Complete correction of plasma Ca levels was observed shortly after the institution of hormonal substitutive therapy. Despite the evidence of increased Ca mobilization from bone, bone biopsies in two patients did not show any signs of cell-mediated bone resorption; instead, bone cell activity appeared to be suppressed. Thus, glucocorticoid deficiency appears to induce Ca mobilization from bone stores by mechanism(s) unrelated to bone remodelling processes.


Tongue necrosis in temporal arteritis provoked by ergotamine. A case of tongue necrosis in a patient with temporal arteritis who was taking ergotamine is described, and the role of ergotamine tartrate in provoking the tongue necrosis is considered. The literature on this unusual complication is critically reviewed, and the value of a carotid angiography in assessing the tongue ischaemia is exemplified.


Erythromycin associated hearing loss in a patient with prior cis-platinum induced ototoxicity. A case is reported of reversible sensorineural hearing loss associated with intravenous erythromycin treatment. Cis-platinum induced high frequency hearing loss developed nine months previously during treatment for stage IV papillary cystadenocarcinoma. Renal and hepatic function were normal; however, serum erythromycin levels were elevated. Clinical recovery promptly followed discontinuation of erythromycin.


Prevention of heterotopic bone formation with low dose radiation therapy. Radiation therapy to control heterotopic bone formation does not appear to be commonly used in sites other than hips where effective control is evident following arthroplasty. Reported are the results in 12 sites in 10 patients including three with treatment to the elbow, humerus, and ulna. Ten sites received a radiation dose of 10.00 Gy, one 16.00 Gy, and one was treated to 20.00 Gy, all delivered in 2.00 Gy fractions. Preoperative and follow-up x-rays were reviewed and graded. There was no clinically significant regrowth of heterotopic bone. Five sites (42%) demonstrated mild regrowth or persistence following surgery with the other seven (58%) showing no evidence of heterotopic bone. No complications were seen. Radiation therapy is effective for the prevention of heterotopic bone after total hip arthroplasties as well as surgery for fractures to other areas.


Flow cytometry applications in detection and classification of leukemia/lymphoma. The increase in availability of monoclonal antibodies that specifically react with surface markers on human leukocyte subsets and introduction of more user-friendly clinical flow cytometers have resulted in an evolution of flow cytometry away from a strictly research entity into an important tool in the clinical laboratory. The specific and sensitive detection of leukemia and its differentiation from benign lymphoproliferations is one area in which flow cytometry can substantially impact patient care. The application of immunophenotyping of leukemia/lymphoma using monoclonal antibodies and flow cytometry and the basic science of its instrumentation are presented. Case reviews illustrate the utility of immunophenotyping in making the correct lineage assignment and diagnosis.


A novel method to differentiate between ping-pong and simultaneous exchange kinetics and its application to the anion exchanger of the HL60 cell. We have developed a new test to differentiate between ping-pong and simultaneous mechanisms for tightly coupled anion exchange. This test requires the use of a dead-end reversible noncompetitive inhibitor. As an example, we have applied the test to the anion exchanger of the HL60 cell using the salicylic acid derivative 3,5-diiodosalicylic acid (DIS), which reversibly inhibits HL60 cell Cl/Cl exchange. The concentration of DIS that causes 50% inhibition (ID50) increased only slightly as either intra- or extracellular chloride was increased, indicating that DIS inhibits HL60 anion exchange in a noncompetitive manner. In agreement with this observation, plots of the slope of the Dixon plot as a function of 1/[Clo] or 1/[Cli] were fit with straight lines with nonzero intercepts, indicating that DIS does not compete with either of the substrates ([Clo] and [Cli]). The secondary Dixon slope test is based on the fact that, for a dead-end inhibitor such as DIS, the slope of the Dixon plot slope vs. 1/[Cli] (secondary Dixon slope or SDS) is independent of extracellular Cl when the exchange mechanism follows ping-pong kinetics. Similarly, the SDS calculated from a plot as a function of 1/[Clo] is also independent of intracellular Cl for a ping-pong exchanger. In contrast to this prediction, we found that for DIS inhibition of Cl/Cl exchange in HL60 cells the slope of the Dixon plot slope vs. 1/[Cli] decreased by a factor of 2.5-fold when [Clo] was increased from 1 to 11 mM (P < 0.0001). This change in the SDS rules out ping-pong kinetics, but is consistent with a simultaneous model of Cl/Cl exchange in which there are extra- and intracellular anion binding sites, both of which must be occupied by suitable anions in order to allow simultaneous exchange of the ions.


Adaptation-promoting effect of IP3, Ca2+, and phorbol ester on the sugar taste receptor cell of the blowfly, Phormia regina. The fly has a receptor cell highly specialized for the taste of sugars. We introduced inositol 1,4,5-trisphosphate (IP3), Ca2+, or a phorbol ester, 12-deoxyphorbol 13-isobutylate 20-acetate (DPBA), into the cell and investigated their effects on the response to sucrose. The sugar receptor cell generates impulses during constant stimulation with sucrose, but the impulse frequency gradually declines as the cell adapts to the stimulus. Thus, this gradual reduction of the impulse frequency is a direct manifestation of adaptation of the cell. These reagents accelerated the gradual reduction of the impulse frequency, although the initial impulse frequency was little affected. In contrast to these reagents, glycoletherdiamine-tetraacetate (EGTA) retarded the gradual reduction of the impulse frequency. Moreover, when IP3 and DPBA were applied together, the gradual reduction of the impulse frequency was more accelerated than when either IP3 or DPBA was applied. When IP3 and EGTA were applied together, however, the accelerating effect of IP3 tended to be canceled. Based on these results, we hypothesized that an intracellular cascade involving inositol phospholipid hydrolysis, intracellular Ca2+ mobilization, and protein kinase C-mediated phosphorylation promotes adaptation of the sugar receptor cell.


Assessment of former and newly developed HBV assays in a Third World setting. Newly available HBV serological assays have not been established routinely in most underdeveloped countries. Utilizing enzyme-immune assays to determine the presence of pre-S1 antigen and anti-pre-S2, and using two conventional hybridization techniques and the PCR assay to detect HBV-DNA, we studied 30 HBsAg chronic carriers and as a reference group 10 subjects whose only HBV routine marker was anti-HBc. Seventy-nine percent of the HBeAg positive carriers showed detectable HBV-DNA by a non-radioactive slot-blotting technique. The PCR assay was more sensitive than the slot-blotting technique, detecting HBV-DNA in anti-HBe positive patients with moderate or normal ALT activity. Pre-S1 antigen was mostly related to the presence of HBsAg and anti-pre-S2 was associated with active viremic state, increased ALT activity (ranges 51 to 640 IU/L), and with self-limited HBV infection. The presence of HBV-DNA in the group with anti-HBc only was detectable solely by the PCR assay. For an underdeveloped country the addition of a PCR assay or pre-S/anti-pre-S protein tests to the current assessment procedures of HBV chronic infection should be used only in selective cases. HBeAg/anti-HBe serological evaluation and HBV-DNA detection by a non-isotopic conventional hybridization technique still remain as useful tools to screen initially for the presence of viremia in chronic HBsAg carriers. The presence of HBV-DNA in individuals with anti-HBc only suggests that anti-HBc screening should be maintained and expanded to all the blood banks of less industrialized countries where the rate of HBV infection in apparently healthy people tends to be high.


The detection in urine specimens of IgG and IgM antibodies to hepatitis A and hepatitis B core antigens. The use of urine as a noninvasive specimen for the diagnosis of hepatitis A (HAV) and hepatitis B (HBV) virus infections was investigated. Specimens of urine were collected at the same time as blood or saliva specimens, or singly in cases of previously serologically confirmed recent infection. The specimens were tested for IgG and IgM anti-HAV and anti-HBc by immunoglobulin class-specific capture radioimmunoassays (GACRIA and MACRIA). On the basis of assays on urine specimens it was possible to distinguish between individuals who were susceptible or immune to HAV or who had recently been infected with HAV. Using assays on 327 corresponding saliva specimens as reference tests, the observed sensitivity and specificity of tests on urine specimens by anti-HAV GACRIA were 98.9% and 99.1%, respectively, and by anti-HAV MACRIA were 95.8% and 99.6%, respectively. IgM and IgG anti-HBc were detected readily in the urine of 35 acute or recent cases of hepatitis B but were not found in the urine of seronegative individuals. Of the urine specimens from 52 individuals who were HBsAg carriers or who had had long past HBV infections, 49 contained detectable IgG anti-HBc. Of urine specimens from 42 HBsAg carriers, 11 contained raised IgM anti-HBc levels. Urine, which is a convenient specimen to collect, can be used to study outbreaks of hepatitis A, to ascertain the HAV immune status of individuals, to differentiate hepatitis A from hepatitis B, and to identify individuals who have been naturally exposed to HBV.


Mechanism of astrovirus entry into Graham 293 cells. Astroviruses are intestinal pathogens associated with gastroenteritis in man and animals. The mechanism of internalization into host cells has not been reported previously. The cell entry pathway of serotype 1 human astrovirus into 293 cell line was studied biochemically and morphologically. Viral infection was monitored by indirect immunofluorescence. Infected cells were treated with the lysosomotropic agents ammonium chloride, methylamine, and dansylcadaverine or the ionophore monensin to raise the intraendosomal and intralysosomal pH. All drugs tested inhibited the early stages of infection whereas they did not interfere with the viral binding to the plasma membrane. The presence of astrovirus particles was detected by electron microscopy in coated pits and later in coated vesicles. The data indicate adsorptive endocytosis as the most probable mechanism by which astroviruses enter susceptible cells.


Detection of respiratory syncytial virus in acute bronchiolitis in infants. Direct detection of respiratory syncytial (RS) virus antigen in nasopharyngeal secretions (NPS) provides the most rapid diagnostic test for RS infection, but more sensitive methods might be more beneficial in the study of virus shedding. RS virus RNA was extracted from cells stored at -70 degrees C either in suspension with added RNAse inhibitor or as a pellet without inhibitor. The RNA was reverse transcribed, the resultant cDNA amplified by the polymerase chain reaction and detected by ethidium bromide staining after electrophoresis through agarose gel (RT-PCR). Of 217 specimens tested, 106 were positive by antigen detection, 99 by RT-PCR, and 92 by virus isolation. In a series of 97 sequential NPS specimens from 15 infants in whom RS virus induced bronchiolitis was confirmed, antigen detection proved most sensitive in the first week after onset and RT-PCR detected most positive specimens in the second week. Storage of the cells as a pellet proved more satisfactory than storage as a suspension. A further round of amplification using nested primers increased the number of positive results obtained by RT-PCR. The sensitivity of antigen detection using directly labelled monoclonal antibody to RS virus was slightly higher than that of RT-PCR, but the specificity was slightly lower.


Venezuelan equine encephalitis-specific immunoglobulin responses: live attenuated TC-83 versus inactivated C-84 vaccine. Venezuelan equine encephalitis (VEE)-specific immunoglobulin responses to the two vaccines, TC-83 (a live attenuated vaccine) and C-84 (a formalin inactivated vaccine derived from the TC-83 strain of virus) were evaluated using an antigen and isotype-specific enzyme-linked immunoadsorbent assay (ELISA). The VEE-specific ELISA for IgG, IgG subclasses, IgA and IgM were developed and standardized using sera from vaccine-exposed and unexposed human subjects. Paired human sera (before and 28 days after immunization) were tested from laboratory workers vaccinated with either TC-83 (Group A: 20 paired sera from subjects receiving a single TC-83 vaccine and with no prior history of vaccination) or C-84 in varying schedules (Group B: 19 paired sera from subjects who had a distant vaccination history to TC-83 but no evidence of neutralizing antibody; Group C: 19 paired sera from subjects receiving their first C-84 vaccination and no prior documented history of vaccination; Group D: 15 paired sera from subjects receiving a C-84 booster vaccination with prior history of C-84 but no TC-83 exposure). Sera were all tested for viral neutralization in vitro using a Vero cell monolayer for culturing virus and establishing 80% plaque reduction for each serum tested. All pre-sera tested demonstrated no plaque reduction neutralization at a level of 80% for a dilution of 1:10. ELISA antibody titers for all pre-sera with no prior VEE exposure through vaccination or possible environmental factors were negative at a titer of 1:160 for IgM, 1:80 for IgG, IgA, and G subclasses.(ABSTRACT TRUNCATED AT 250 WORDS)


Cuticular hydrocarbons, isoenzymes and behavior of three populations of Anopheles darlingi from Brazil. Three populations of Anopheles darlingi were studied for cuticular hydrocarbons, isoenzymes and patterns of peak biting activity. Differences were found in specimens from Costa Marques, a malaria endemic area; Dourado, a site with a very exophilic population and Juturnaíba, located near the type locality. Twelve hour collections from sunset to sunrise showed that An. darlingi from Costa Marques had a bimodal biting activity profile with a major peak at sunset and a minor peak at sunrise. At Dourado, the pattern was trimodal, with peaks at both morning and evening periods of twilight and near midnight. The Juturnaíba population showed a slight increase in activity near 2000 and 0100 h. Nei's genetic distances, determined by isoenzyme electrophoresis between pairs of populations, were low (D < or = 0.049). Using discriminant analysis for the cuticular hydrocarbons, 92.4% of the specimens from Costa Marques, 91.2% of the specimens from Dourado and 61.3% from Juturnaíba were correctly identified. Cuticular hydrocarbon and isoenzyme results matched very well: the smaller the Nei's distance, the more misidentifications occurred in the jackknife estimator used in the cuticular hydrocarbon analysis. This is the first report of cuticular hydrocarbon analysis in combination with isoenzymes to investigate neotropical anopheline species.


Infection of adult mosquitoes by the entomopathogenic fungus Erynia conica (Entomophthorales: Entomophthoraceae). The infection of adult mosquitoes by the entomopathogenic fungus Erynia conica is presented for the first time. Adult Aedes aegypti were exposed to conidial showers from field-collected chaoborid, tipulid and chironomid cadavers for 24 h under conditions of 100% RH and 15 degrees C. Up to 24% of the adults were killed by the mycosis. Cadavers of Ae. aegypti produced conidia that were infective to other adult Ae. aegypti; however, rates of infection were never more than 12%. Nevertheless, Ae. aegypti served as the laboratory host for E. conica via mosquito-to-mosquito serial passages for up to 6 months. Adult Culex restuans were also susceptible to infection by E. conica.


Evaluation of a funnel trap for collecting copepods and immature mosquitoes from wells. A simple funnel trap which inverts on entry to and exit from the water, was evaluated with respect to sampling the aquatic fauna of wells in and around Fortaleza, Brazil. Mosquito larvae, copepods, ostracods, fish and tadpoles were collected. When known numbers of Culex quinquefasciatus larvae and Mesocyclops aspericornis copepods were introduced into negative wells, overnight sampling resulted in 50% positivity of traps when 10 larvae (1/1,000 cm2) and 25 copepods (1/176 liters) were introduced. All traps were positive when 100 and 400 larve and copepods, respectively, were present. Over a range of 10-2,000 and 25-800 released larvae and copepods, respectively, average recovery rates were 6.1 and 3.6%, but on the basis of one sample, the variability was such that a precise estimate of absolute abundance could not be made.


A review of malaria in Iran, 1975-90.

A review of malaria in Iran, 1975-90. Since 1958, when the malaria eradication program officially started in Iran, great strides has been made in controlling the disease in most of the country. However, because of certain technical, operational and administrative problems, malaria is still highly prevalent in southeastern Iran, affecting 6% of the population. The situation of malaria in Iran from 1975 through 1990 is discussed in detail, with particular emphasis given to the epidemiological characteristics and vector transmission factors in each region of the country.


Mosquito size and multiple transmission of avian malaria in the laboratory. Probing mosquitoes salivate before ingesting blood, and malaria sporozoites are transmitted during this phase of feeding. Large and small Aedes aegypti infected with Plasmodium gallinaceum were allowed to probe briefly on a series of 3 naive chicks. Large mosquitoes were more infective overall, but there was no difference in the ability of either size class to infect the first host. Large mosquitoes were more likely than small mosquitoes to infect more than one host during serial feeding.


Correlation of Aedes sierrensis captures at human sentinels with CO2-baited Fay-Prince and duplex cone traps. The efficiency of the duplex cone and Fay-Prince traps for monitoring adult male and female Aedes sierrensis was evaluated at 3 field sites in California. The numbers of females captured by both types of traps were significantly correlated with human sentinel collections. The Fay-Prince trap captured more Ae. sierrensis females than the duplex cone trap and was a better tool for estimating female activity levels. There was no significant correlation between the number of males captured in Fay-Prince traps and at humans. Male numbers in duplex cone trap collections explained only 27% of the variation in the number of males collected at sentinels, suggesting that neither trap is a robust tool for estimating male activity around humans.


Susceptibility of Aedes albopictus from China to insecticides, and mechanism of DDT resistance. Aedes albopictus collected from urban districts of China (12 strains) has developed high levels of DDT resistance, while 2 strains collected from rural areas remain susceptible. The mechanism of DDT resistance was due to intensified activity of DDT-dehydrochlorinase, but the penetration of DDT into the mosquito body is also different. This may possibly have had some influence on the resistance levels of some strains, but it seems unlikely that was the main mechanism of DDT resistance.


Dispersal of adult female Culex annulirostris in Griffith, New South Wales, Australia: a further study. The dispersal of Culex annulirostris was studied during February 1986 in Griffith, N.S.W. using a mark-release-recapture technique. Parity was determined of recaptured females and a sample of the population at release. Parity rates of the 2 populations were comparable, and no significant differences were detected between the dispersal characteristics of the nulliparous and parous recaptured females. The maximum flight distance observed was 12 km, the limit of the trapping network. It was estimated that the mean distance traveled was 4.4 km and 36.6% (n = 377) of the population dispersed further than 5 km. The majority (81.2%, n = 377) of recaptures were taken within 2 days of release and the rate of dispersal of the population was estimated at 2.2 km/day.


Sporozoite transmission by Anopheles freeborni and Anopheles gambiae experimentally infected with Plasmodium falciparum. A micro-membrane feeding technique was used to evaluate sporozoite transmission for Anopheles freeborni and An. gambiae experimentally infected with Plasmodium falciparum. From cohorts of infected mosquitoes with equivalent sporozoite loads, 75.9% of 29 An. freeborni transmitted a geometric mean (GM) of 4.9 sporozoites and 80% of 30 An. gambiae transmitted a GM of 11.3 sporozoites. Ingested sporozoites, in the blood meal immediately after feeding, were detected in 86.2% of 29 An. freeborni (GM = 9.0) and in 70% of 30 An. gambiae (GM = 44.1). Overall, sporozoites were transmitted and/or ingested by 90% of both species. Most infective mosquitoes transmitted < 1% of the total sporozoites in the salivary glands, and only up to 30% of the variation in transmission, ingestion, or total sporozoite output was related to sporozoite loads. The demonstration that An. gambiae transmitted more than twice as many sporozoites as An. freeborni is the first indication that vector species of anopheline mosquitoes differ in their innate potential for sporozoite transmission.


A simple method for cultivating freshwater copepods used in biological control of Aedes aegypti. A simple method for indoor and outdoor cultivation of Mesocyclops aspericornis, Macrocyclops albidus and Mesocyclops n. sp. copepods is presented. This method utilizes Chilomonas sp., Paramecium caudatum and fresh lettuce as food sources for copepod cultures. Steps for initiating and maintaining copepod cultures are provided.


Reduction in the susceptibility of Aedes aegypti to Brugia malayi infection after treatment with ethyl methanesulfonate. The susceptibility to Brugia malayi infections of F2 and F4 progenies of Aedes aegypti (Black Eye strain) treated with ethyl methanesulfonate (EMS) was tested. Both 3-day-old males and females were treated with 0.025, 0.050, 0.075 and 0.10% EMS. Control and treated females were then mated with normal or treated males to recover F1 progeny. F2 offspring were derived from sibling intercrosses, and 3 lines were established by further intercross matings to generate the F4. Susceptibility in the 0.025, 0.050, 0.075 and 0.10% EMS F2s was reduced by 13, 12, 4 and 25%, respectively. The 0.025% and 0.050% EMS F2 females showed a 29 to 39% decrease in mean L3 numbers. At 0.075 and 0.10% EMS, mean L3 numbers decreased by 0.8 and 71%, respectively. The F4 populations gave overall infections of 65, 56 and 22% for the control, 0.25 and 0.10% EMS lines, respectively. Mean L3s were reduced by 24 and 77%, respectively, in the 0.025 and 0.10% F4 EMS-selected populations.


A radio controlled box for the remote release of insects. A description is given of a radio controlled box for the remote release of insects. It consists of a plaster-lined plastic container fitted with a battery and radio receiver which control a servo to open and close the lid. Instructions for construction and use are given.


Northernmost occurrences of the protistan pathogen, Coelomomyces stegomyiae var. stegomyiae. Now reported as parasitizing the ovaries of female Aedes albopictus on Kabeshima (33.33N x 129.53E), Coelomomyces stegomyiae var. stegomyiae had been found earlier in larvae of this mosquito on Mikura-jima (33.53N x 139.35E). These findings from 2 widely separated little Japanese islands constitute the parasite's most northerly records to date. Few previous reports of Coelomomyces spp., none concerning C. stegomyiae, have involved adult mosquitoes. Possible reasons for this are advanced.


Enhancement of the solubilities of polycyclic aromatic hydrocarbons by weak hydrogen bonds with water. The thermodynamics of mobile order is applied to predict the aqueous solubility of liquid and solid aliphatic and polycyclic aromatic hydrocarbons. The solubility values are mainly determined by the magnitude of the hydrophobic effect. However, contrary to the solubilities of the alkanes, the solubilities of polycyclic aromatic hydrocarbons in water predicted in absence of solute-solvent hydrogen (H) bonds are systematically too low. This shows the contribution of weak specific interactions between the OH groups and the pi electrons of the aromatic substances. According to the theory, these interactions are characterized by a stability constant KO which can be derived from solubility data. At 25 degrees C, this constant amounts to 80 cm3/mol, the order of magnitude of which can be explained by the competition of these intermolecular bonds with the rather weak self-association bonds in the secondary chains of water.


Predicting the product specificity and coupling of cytochrome P450cam. We present an analysis of several molecular dynamics trajectories of substrate-bound cytochrome P450cam. Trajectories were calculated for the native substrate, camphor, as well as for the alternative substrates, norcamphor and thiocamphor. The system modeled consisted of the crystallographically resolved amino acids, the heme group with a single oxygen atom as the distal ligand, the bound substrate, and the crystallographic waters. These trajectories of the presumptive ferryl oxygen intermediate were used to predict regiospecificity of hydroxylation and coupling between NADH consumption and product formation. Simple geometric criteria in combination with electronic considerations were used to calculate the probability of hydroxylation at specific sites on the substrate. We found that for all the cases examined, the predicted product ratios were in good agreement with the experimentally observed values. We also determined that these simple geometric criteria can be used to predict the degree of coupling between NADH consumption and product formation for a given substrate, which was in good agreement with the experimental values.


Automatic superposition of drug molecules based on their common receptor site. We have previously developed a new rational method for superposing molecules in terms of submolecular physical and chemical properties, but not in terms of atom positions or chemical structures as has been done in the conventional methods. The program was originally developed for interactive use on a three-dimensional graphic display, providing goodness-of-fit indices on molecular shape, hydrogen bonds, electrostatic interactions and others. Here, we report a new unbiased searching method for the best superposition of molecules, covering all the superposing modes and conformational freedom, as an additional function of the program. The function is based on a novel least-squares method which superposes the expected positions and orientations of hydrogen bonding partners in the receptor that are deduced from both molecules. The method not only gives reliability and reproducibility to the result of the superposition, but also allows us to save labor and time. It is demonstrated that this method is very efficient for finding the correct superposing mode in such systems where hydrogen bonds play important roles.


QSAR of conformationally flexible molecules: comparative molecular field analysis of protein-tyrosine kinase inhibitors. Comparative Molecular Field Analysis (CoMFA) has been applied to a study of quantitative structure-activity relationships (QSAR) of conformationally flexible molecules. The relationship between three-dimensional structure and activity of 20 styrene derivatives which inhibit protein-tyrosine kinase was determined. A technique was developed that allows accurate prediction of the inhibitory activity of these molecules and identification in each case of the active conformation. The problem of multiple energetically acceptable conformations was approached in an iterative procedure. Use was made of the varying degrees of symmetry among the molecules. First, CoMFA QSAR models were developed using only those compounds that possess a symmetrical substituent pattern on the phenyl ring. These CoMFA models were then used to select the active conformers of the less symmetrical compounds in the set. Allowing multiple conformers for each compound in the dataset yielded higher crossvalidated r2 values and better predictivity of the QSAR models. Different probe atoms (C+, O-, neutral C) were explored, the O- probe atom exhibiting the highest selectivity in the conformer selection process.


'ValleyScan': a new two-bond drive technique for the calculation of potential energy surfaces with less computational effort. A novel, CPU-time inexpensive two-bond drive technique, called 'ValleyScan' [1], is described. It makes it possible to omit the chemically nonrelevant points of high energy, which are normally part of a two-dimensional (2D) grid calculation. The new procedure works well for the calculation of the ring inversion of cyclic molecules, but should also be useful for other 'two-bond' problems e.g. side-chain movements in larger molecules (e.g. proteins). The algorithm is based upon pseudocode description and can easily be included in any molecular modelling software with an open user interface. Starting from an energy minimum, the calculation scans the potential surface in all directions up to a user-defined energy limit. With this strategy, attention is paid only to the area close to the stationary points - energetically higher structures do not have to be calculated. We applied the procedure to the test molecules 1,3-cyclohexadiene (4), 2H-pyran (5) and 6H-dibenzo[b,d]pyran (6). The extension of this method to the variation of more than two dihedral angles for more complex problems, e.g. sterically more hindered rotation, is in progress.


Similarity screening of molecular data sets. Three-dimensional (3D)-database searches are now being widely applied to determine potential new active molecules. Many structural data sets obtained as a result of these searches are still large in size. In this paper we apply molecular similarity calculations as a rapid method to screen two such data sets. In the first investigation, synthetic candidates, produced as a result of a tendamistat beta-turn mimic search, were tested for their ability to imitate the beta-turn backbone. In the second study, structures extracted through a histamine pharmacophore query search were examined on the basis of their electronic similarity to histamine. Molecular similarity is shown to provide a rapid means of gaining insight into the composition of molecular data sets, with possible implications for future full 3D-database searches.


Heterofullerenes: structure and property predictions, possible uses and synthesis proposals. Substituting carbon atoms of fullerenes by heteroatoms and vacancies will lead to new and yet unknown spherical-shaped molecules termed hereafter as heterofullerenes. The enormous structural diversity of these molecules is investigated and their structural, electronic and thermochemical properties are predicted using semiempirical computations. Computational results for complexes with ions lead to the hypothesis that these molecules behave like microscopic Faraday cages in which the electrons concentrate on the outer side of the sphere. It is predicted that some of these heterofullerenes are structurally and electronically similar to phthalocyanines and related molecules but offer many additional advantages. Potential uses such as adding heterofullerenes to fullerene materials, as superior starting materials for the fabrication of diamonds, as catalysts in hydrogenation reactions, as components of materials dominated until now by phthalocyanines, etc., are discussed. Simple synthetic routes to these compounds that are based on minor alternations of existing methods for fullerene production are proposed. On the basis of the thermochemical calculations, we believe that the most promising possibility consists of using metal cyanide/graphite composite target rods instead of pure graphite rods as in a conventional fullerene synthesis.


A method for assessing drug therapy appropriateness. This study evaluated the reliability of a new medication appropriateness index. Using the index, independent assessments were made of chronic medications taken by 10 ambulatory, elderly male patients by a clinical pharmacist and an internist-geriatrician. Their overall inter-rater agreement for medication appropriateness (ppos) was 0.88, and for medication inappropriateness (pneg) was 0.95; the overall kappa was 0.83. Their intra-rater agreement for ppos was 0.94 overall, for pneg was 0.98 overall while the overall kappa was 0.92. The chronic medications taken by 10 different ambulatory elderly male patients were independently evaluated by two different clinical pharmacists. Their overall inter-rater agreement for ppos was 0.76, and for pneg was 0.93, while the overall kappa was 0.59. This new index provides a reliable method to assess drug therapy appropriateness. Its use may be applicable as a quality of care outcome measure in health services research and in institutional quality assurance programs.


Cholesterol and coronary artery disease: age as an effect modifier. An elevation of serum cholesterol has been one of the more frequently cited risk factors for coronary heart disease, found in both case-control and cohort studies. As a result, this country has undertaken massive screening of adults older than 20 years of age in an attempt to identify those persons with cholesterol levels greater than 200 mg/dl, and follow up with an active approach for intervention. The suggested cutpoints for borderline (200-240 mg/dl), and definite (> or = 240 mg/dl) hypercholesterolemia have been applied to all age groups despite suggestions of a diminution of risk conferred by cholesterol in the elderly. This study of 2544 white men undergoing coronary angiography shows that for all men, aged 25-84 years, plasma cholesterol levels were associated with an increase in coronary artery occlusion (rs = 0.15, p < 0.01). However, when stratified by age, this association held only for the younger men, the association diminishing to near zero in the oldest age group. The negative interaction between cholesterol levels and age in predicting coronary artery disease proved highly significant (p < 0.001) in multivariable linear regression analysis, suggesting that cholesterol levels are much less predictive of coronary artery disease in the elderly as compared to the young. These results point to the need for a more finely tuned set of criteria for the evaluation of hypercholesterolemia, one that takes into account the age of the screenee.


Association of lifestyle and personality characteristics with blood pressure and hypertension: a cross-sectional study in the elderly. The association between certain lifestyle and personality characteristics and blood pressure in the elderly was assessed in a cross-sectional study of 843 independent living 60-87 year old volunteers. They comprised 338 women and 505 men of whom 35 and 30% respectively were being treated with antihypertensive drugs. Among untreated volunteers, 28% of women and 28% of men had systolic blood pressure greater than 160 or diastolic blood pressure greater than 95. Isolated systolic hypertension was found in 20% of untreated women and 14% of untreated men. Lifestyle factors and personality characteristics associated with blood pressure were similar to those described in younger adult populations, although there were some differences related to gender and whether subjects were being treated for hypertension. Stepwise multiple regression showed that higher blood pressure was associated with greater body mass index (BMI), alcohol intake and coffee drinking and measures of irritability. Increased physical activity, and high values for measures of suspicion and extraversion were negatively related to blood pressure. Age was positively related to systolic, but not to diastolic blood pressure. The presence of hypertension was significantly associated with self-reports of raised cholesterol, diabetes or angina, as well as past history of heart failure, heart attack or stroke. Thus, in this elderly free-living population blood pressures are still significantly associated with behavioural characteristics which could be further investigated as an alternative or adjunct to antihypertensive therapy.


Criteria for the use of Sartwell's incubation period model to study chronic diseases with uncertain etiology. This study explores the conditions under which Sartwell's incubation period model may be appropriate for identifying a primary time period of etiologic risk for chronic diseases with uncertain etiology. The investigation begins with a description of the evolution of the application of Sartwell's model from infectious to chronic diseases. The model's underlying assumptions and some concerns about its use in the chronic disease context are specified. These concerns are addressed by data simulations and analyses of empirical data from the Connecticut Tumor Registry and the Radiation Effects Research Foundation. The results indicate that the distribution of age at diagnosis (i.e. onset) for chronic diseases is not necessarily lognormal. However, the representativeness of age distribution of the case series can affect the distribution's form; hence, it is important to determine the extent of "missing" cases, particularly those lost through truncation. Moreover, a lognormal age distribution may occur with both prenatal and age-related postnatal exposures. These findings suggest that only under certain conditions will Sartwell's model be useful in the study of chronic diseases of uncertain etiology, and indicate some caveats for interpretation of the results.


Assessment of excess risks in case-base studies. Miettinen and Caro (J Clin Epidemiol 1989; 42: 325-331) [6] put forth principles of non-experimental assessment of excess risks in case-base studies; in such a design, risk difference is assessed by estimating the denominators of the proportions of cases among exposed and comparable unexposed subjects by means of a representative sample from the base population of the study. They provided appropriate formulations for the point estimation of risk differences for various exposure patterns with allowance for covariables by means of stratified analysis. However, in small samples point estimates can be uncertain. In this paper, first, likelihood-based statistics are derived which can be used for interval estimation (and also point estimation and significance testing) of risk differences. The unified approach generalizes to stratified analysis. Second, the procedure is parameterized for inferences about risk ratios using a chi-square function in analogy with the profile likelihood method for full cohort analysis. Third, the approach is extended from the study of a binary exposure variable to a risk function analysis under the Poisson regression model. The suggested estimation procedure is conceptually clear and computationally simple in that the modelling, unlike the models considered by Prentice (Biometrika 1986; 73: 1-11) [3] for the analysis of case-base data, focuses directly on the comparison of risks between exposure categories in the study base and thus involves no covariance between the cases and the base sample.


Self-reported depression and negative pregnancy outcomes. Studies addressing the association of depressive symptoms late in pregnancy with pregnancy outcome are lacking. We administered the revised Beck Depression Inventory (BDI) in the third trimester to 323 inner-city adolescents and 389 adults, who were mostly from U.S. minority groups (28.7% Puerto Rican, 61.8% black, 9.6% white). The BDI total score was regressed (as a continuous variable) on indicators of poor pregnancy outcome. There was no relationship of BDI scores with pregnancy outcome in the adolescents. However, among the adult gravidas the risk of a poor outcome rose 5-7% (p < 0.05) for each point the BDI total score increased. For the adults, at a cut-off score of 21 for the BDI, suggestive of clinical depression, the risk of delivering a low birth weight infant of < 2500 g was 3.97 (95% confidence interval [CI] 3.80-4.15); the risk for having a preterm delivery at < 37 completed weeks' gestation was 3.39 (95% CI 3.24-3.56); and their risk of having a small-for-gestational-age infant at < 10th percentile for standards was 3.02 (95% CI 2.88-3.17). Future research should address the physiological mechanisms associated with symptoms of depression that might contribute to an increased risk of poor outcomes and extend the findings to gravidas from different socioeconomic strata.


The Edinburgh Claudication Questionnaire: an improved version of the WHO/Rose Questionnaire for use in epidemiological surveys. The WHO/Rose Questionnaire on intermittent claudication was developed in 1962 for use in epidemiological surveys, and has been widely used. Several population studies have shown, however, that it is only moderately sensitive (60-68%), although highly specific (90-100%). In this study, reasons for the poor sensitivity and good specificity were determined following its application to 586 claudicants and to 61 subjects with other causes of leg pain. The results showed two important findings: firstly, that over half of the false negatives were produced by one question alone; and secondly that only three questions were required to maintain the specificity of the questionnaire. This knowledge, in conjunction with the pre-testing of additional questions, enabled a new questionnaire to be constructed: the "Edinburgh Claudication Questionnaire". This questionnaire was tested on 300 subjects aged over 55 years attending their general practitioner, and found to be 91.3% (95% CI 88.1-94.5%) sensitive and 99.3% (95% CI 98.9-100%) specific in comparison to the diagnosis of intermittent claudication made by a physician. The repeatability of the questionnaire after 6 months was excellent (kappa = 0.76, p < 0.001). These results suggest that this revised version of the WHO/Rose Questionnaire should be adopted for use in future epidemiological surveys of peripheral vascular disease.


Oral contraceptive use and cervical intraepithelial neoplasia. To explore the somewhat controversial relationship between oral contraceptives and pre-invasive cervical cancer, 103 cases of biopsy-confirmed cervical intraepithelial neoplasia (CIN) II or CIN III were compared with 258 controls who had normal cervical cytology. Cases were slightly less likely than controls to have ever used oral contraceptives; the odds ratio, controlling for age, socioeconomic status, barrier method use, smoking history, age at first sexual intercourse, number of sex partners, current marital status, and number of Pap smears, was 0.7 (95% CI 0.3-1.6). Recency, latency, duration, and age at first oral contraceptive use were evaluated and in no instance was oral contraceptive use positively associated with CIN. This study adds to the body of knowledge that oral contraceptives are not associated with pre-invasive cervical cancer. Further, if oral contraceptive users continue to be regularly screened, their risk of developing the more invasive lesions should be very low.


A comparison of the effects of cholesterol on CHD mortality in black and white women: twenty-eight years of follow-up in the Charleston Heart Study. The relationship between cholesterol and 28-year CHD mortality in women was evaluated in the Charleston Heart Study. Linear, quadratic, and cubic models were investigated using Cox proportional hazards regression analysis. In white women, the linear, quadratic, and cubic terms for cholesterol were significant suggesting an asymmetric J-shaped relationship. In black women, only the linear term in all three models was statistically significant suggesting an increasing CHD mortality rate with increasing cholesterol level. The lack of consistency of results by different statistical analyses in black women make conclusions concerning the nature of the relationship between cholesterol and CHD mortality less strong in black women than in white women. Compared with women having a cholesterol value equal to the mean of the group (241 mg/dl), white women having a cholesterol value one standard deviation above the mean (s = 52.5 mg/dl) had a 60% higher CHD mortality rate (hazard ratio = 1.6, 95% CI: 1.2-2.1). In black women, the estimated hazard ratio for a one standard deviation (s = 47.8 mg/dl) increase in cholesterol is 1.4 (95% CI: 1.03-1.8). The results suggest that the relationship of cholesterol to CHD mortality is different in white and black women. The relationship in white women appears to be curvilinear and represented by an asymmetric curve while the relationship in black women is not curvilinear and the overall pattern of association, while possibly linear, is equivocal.


Sample size calculations for the log rank test: a Gompertz model approach. Sample size calculations for clinical trials dealing with survivorship are often based on an exponential model. This model is inappropriate when a non-zero proportion of the population is expected to have indefinite survival. In such cases the Gompertz model offers a reasonable alternative. A method for calculating the required accrual time for a clinical trial in which the treatment arms have Gompertz survival distributions satisfying the proportion hazards assumption is developed. A computer program to perform this method is given, as well as an iterative method that can be used when a computer is not available.


Epidemiologic studies of electric and magnetic fields and cancer: a case study of distortions by the media. Articles alleging hazards of electric or magnetic fields, based on epidemiologic studies, have appeared in the popular press. Some of these articles, which contain distortions of the scientific evidence, have been cited in the scientific and medical literature, thereby being given some degree of apparent legitimacy. In particular, articles appeared in 1989 in The New Yorker magazine, claiming a strong association between exposure to electric or magnetic fields and cancer. Assertions made in these articles (and a book dealing with essentially the same information) have been challenged by members of the scientific community. This paper will identify some additional misconceptions presented in two more recent articles from The New Yorker. Scientists and physicians should be aware of the deficiencies in these articles, and are encouraged to seek a more balanced view of the research performed in this area.


The influence of referral patterns on the characteristics of diagnostic tests. The discrimination of a diagnostic test--characterized by sensitivity, specificity, likelihood ratio and ROC curve--may be influenced by referral patterns of general practitioners. Symptoms and test results in particular will affect the probability of referral, while the degree of development of the pathological process directly influences the probability of positive test results. Using numerical examples, we analyse and discuss a few specific situations: (1) referral depends only on symptoms; (2) referral depends both on symptoms and on test results; (3) referral depends only on test results. In the first situation, test characteristics and predictive values are invariant over the strata of symptomatology, while in the third situation the predictive values are unchanged. If there is a positive relationship between positive test results and referral probability, overall sensitivity will increase while specificity and likelihood ratio will decrease. A general representation is given for the evaluation of the direction of change of the likelihood ratio as a function of referral probabilities. The shape of receiver-operating characteristic curves is less sensitive to bias, but at the level of specific cut-off points considerable changes may occur.


Discharge from hospital and its effect on surgical wound infections. The Israeli Study of Surgical Infections (ISSI). A multicenter study of 2846 consecutive hernia operations was conducted to identify risk factors for infections that occurred during the hospitalization and post-discharge from hospital. Operated patients were followed-up for 30 days after surgery, whether at home or still hospitalized, and half the wound infection episodes were found to occur at home. Risk factors for both in-hospital and post-discharge infections seemed to be influenced by; (a) the selective nature of discharge, (b) the differential effect some risk factors had on either early or late infections. On any given day, patients selected by the clinical team to remain in hospital were more "at risk" for infection than those who left. As a result, they had a better chance of being diagnosed as infected during hospitalization. By contrast, those who were discharged home were perceived as low risk for complications. Subsequent infections in these patients occurred either due to factors "causing" late infections, therefore, unappreciated at the time of discharge, or unknown risk factors. More study risk factors were associated with in-hospital than with post-discharge infections, especially those associated with "early" infections. The implications of these findings for future evaluations of medical care in hospitalized patients are discussed.


Lifetime data analysis of disease and aging by the Weibull probability distribution. We applied the Weibull distribution to the life-table and age-patterns of diseases in Japan. The life-table follows a composite Weibull distribution composed of initial failure and two stage wear-out failure periods. The extension of lifespan during the past century is manifested as increases in the scale parameters in all three periods and the shape parameters in the wear-out periods with female predominancy. The shape parameters of diseases show time-independent sex-dependent specific values. When consistent changes are observed, such as increases in the shape parameters of tuberculosis and pneumonia, legitimate causes such as prevention and repair at the societal and medical level are present. Cancer and arteriosclerosis share a common range of shape parameters suggesting analogous underlying biological processes. An analysis of the epidemiology of human aging and disease by the Weibull distribution discloses intrinsic properties of man as a biological organization as well as a societal presence.