The impending Canadian prostate cancer epidemic

PURPOSE

To model and forecast prostate cancer incidence and mortality in Canada to the year 2016.

METHODS

Bivariate multiplicative models of prostate cancer incidence and mortality for Canadian men aged 45 years or older, linear in time and Weibull in age, were fitted using weighted non-linear regression.

RESULTS

The number of incident cases of prostate cancer is forecast to increase from 11,355, observed in 1990, to 26,900 by the year 2010 and to 35,200 by the year 2016. The number of deaths are estimated to climb from 3,424, observed in 1991, to an estimated 6,300 by the year 2010, and to 7,800 by the year 2016.

CONCLUSIONS

The dramatic increase in prostate cancer rates with age, coupled with the expected large increase in the elderly Canadian male population and steadily increasing prostate cancer incidence rates will produce very large increases in the number of men who will have prostate cancer over the next 20 years. This has important implications for health care delivery in the future.

[An investigation on therapeutic results of extracapsular cataract extraction and intraocular lens implantation in diabetics]

44 cases (50 eyes) with diabetes and cataract were followed up for 6-30 months after extracapsular cataract extraction (ECCE) with intraocular lens implantation (IOL). No severe intra- and post-operative complications were found and 84% of eyes obtained post-operative corrected visual acuities > or = 0.5. The results suggest that the pre-operative hyperglycemia alone be not a contraindication of the operation. Pre-operatively, if the diabetes of patients with cataract can be controlled by diet or hypoglycemic agent, their glucose level in the blood remains normal and stable for a period of time and there are no other systemic and ocular complications, ECCE with IOL can be performed on such patients and the therapeutic results of the operation can be safe and reliable.

A molecular-based magnet test for malaria

The molecular-based magnet test for malaria is shown to be more sensitive than the thin blood film test. The globally used thin blood film test is less sensitive because it uses preparation steps that result in the reduction of the absolute number of diagnostically pertinent erythrocytes. Several reports of diagnostic error with the thin film test and the thick film test have appeared in the literature. In marked contrast to the commonly accepted tests, the magnet test concurrently partitions and concentrates the infected erythrocytes present in the initial sample. The magnetic test permits a brief and sensitive microscopic-based enumeration of the malaria-infected erythrocytes in the enriched sample. Diagnostically pertinent hemozoin is simply identified through two of its specific molecular properties: paramagnetism and birefringence. The former property mediates the capture and enrichment of malaria-infected erythrocytes within the magnetic flux and the latter property manifests the characteristic birefringence demonstrated by polarized light.

[An experimental study on cultivation of human trigeminal ganglionic cell in vitro and its sensitivity to infection of herpes simplex virus type 1]

We firstly report an experimental study on the sensitivity of primary cultural human trigeminal ganglionic cells infected by herpes simplex virus type 1 (HSV-1) in different time-points. The results indicate that the neuron of human trigeminal ganglia is the most sensitive cell type, the antigen of HSV-1 replicates rapidly within the cytoplasm and cell nucleus, the fibroblasts and glia cells are infected partly by the virus. Therefore, perhaps the neuron is the main harboring cell type.

[The prognostic characteristics of hypertensive left ventricular hypertrophy in a rural population]

One hundred and twenty-six rural hypertensive patients with ECG left ventricular hypertrophy (HT-LVH) were followed up for 10 years to investigate the prognostic characteristics in a population with low prevalence of hypertension (2.93%) and low plasma cholesterol (4.59 +/- 1.00mmol/L). A cohort of age, sex, region and occupation matched hypertensives without LVH (HT, n = 163) and normotensives (NT, n = 275) served as controls. The major cause of death in rural hypertensives with ECG LVH in this study was stroke (56.8%). After stratification of BP, no significant difference of stroke risk was found between patients with LVH and hypertensives without LVH, while cardiovascular risk in the patients with LVH plus ST segment depression persisted. LVH per se seems not to be an independent factor for stroke. The high stroke rate in patients with LVH may be ascribed to the coexisting higher level of BP. After adjustment of coexisting hypertension, ECG LVH based on voltage only was not an independent risk factor of stroke and cardiovascular events, while LVH plus ST segment depression was closely related to cardiovascular events. In this low level, plasma cholesterol did not affect the mortality rate of stroke.

Applications of improved stoichiometric model in medium design and fed-batch cultivation of animal cells in bioreactor

In our previous work (Xie and Wang, 1994a), a simplified stoichiometric model on energy metabolism for animal cell cultivation was developed. Fed-batch experiments were performed in T-flasks using this model in supplemental medium design (Xie and Wang, 1994b). In this work, the major pathways of glucose and glutamine metabolism were incorporated into the stoichiometric model. Fed-batch culture was conducted in a 2-liter bioreactor with appropriate process control strategies. Nutrient concentrations, especially glucose and glutamine, were maintained at constant but low levels through the automated feeding of a supplemental medium formulated using the improved stoichiometric model. The formation of toxic byproducts, such as ammonia and lactate (Hassell et al., 1991), was greatly reduced. The specific lactate production rate was decreased by 62-fold compared with batch culture in bioreactor and by 8-fold compared to fed-batch culture in T-flask using the previous stoichiometric model. Ammonia formation was also decreased compared with both the batch and fed-batch cultures. Most importantly, the monoclonal antibody concentration reached 900 mg l-1, an increase of 17- and 1.6-fold compared with the batch and fed-batch cultures respectively.

The prognostic characteristics of hypertensive left ventricular hypertrophy in a population with low prevalence of hypertension and low plasma cholesterol

One hundred and twenty-six hypertensive patients with ECG left ventricular hypertrophy (HT-LVH) were followed for 10 years to investigate the prognostic characteristics in a population with low prevalence of hypertension (2.93%) and low plasma cholesterol (4.26 +/- 0.91 mmol/L). A cohort of age-, sex-, region- and occupation-matched, randomized hypertensives without ECG-LVH (n = 163) and normotensives (n = 275) served as controls. HT-LVH was found to be associated with an increased risk of overall death, stroke mortality and cardiovascular mortality. The major cause of death in rural hypertensives with ECG-LVH was stroke (56.8%). After adjusting BP and BP stratification, no significant difference of stroke risk was found between patients with and without LVH, while cardiovascular risk persisted in patients with LVH plus ST segment depression. LVH per se did not appear to be an independent factor for stroke death. Higher stroke mortality in patients with LVH may be ascribed to the coexisting higher level of BP. Furthermore, after adjusting for the coexisting hypertension, ECG-LVH in terms of voltage only was not related to the prognosis of stroke and cardiovascular death. The mortality rate of stroke was not affected by plasma cholesterol levels, as the levels seen were in a low range.

Comparison of secondary structures of insulin and proinsulin by FTIR

Although the structure of insulin is known in great detail, that of proinsulin has been little investigated, except for a few CD and NMR studies. The secondary structures of human proinsulin are now compared with those of insulin by Fourier Transformed Infrared (FTIR) studies. The deconvolved and second derivative spectra of proinsulin and insulin in the amide I' band region are closely similar with peaks corresponding to alpha-helix, irregular helix, and 3(10) helix at nearly identical positions. For both proteins, the relative contents of the above structures as calculated from the peak areas are in good agreement with the values obtained from the known structure of crystalline porcine insulin. However, compared with insulin, proinsulin has markedly more unordered structures as indicated by the area under the peak at 1643.4 cm-1. In addition, both peak positions and relative areas for turn structure of the prohormone are different from those for insulin. It appears from the above that the A-and B-chain segments of proinsulin and insulin are similar in their secondary structures, especially in helices. The C-chain segment is largely unordered except in a few beta-turns.

Histological distribution and developmental changes of tropomyosin isoforms in three chicken digestive organs

Histological localization of tropomyosin isoforms in three digestive organs from embryonic and adult chickens was performed by using rabbit antisera against chicken skeletal muscle tropomyosin and against low-Mr-type tropomyosin from chicken small intestine mucosa. The former antiserum (named TM-SH) reacted with alpha, beta, and high-Mr-type isoforms, and the latter (named TM-HL) reacted with alpha, beta, high-Mr-type and low-Mr-type isoforms, alpha and beta Isoforms were detected in muscle cells of the muscular layer and the muscularis mucosa. Low-Mr-type isoforms, however, were detected along the cell membrane and cytoplasm of almost all nonmuscle cells, especially in terminal webs of epithelial cells. Developmental changes of tropomyosin isoforms in digestive organs were studied by two-dimensional gel electrophoresis and image analysis. The relative amounts of alpha and beta isoforms increased in the course of development, but those of low-Mr-type and high-Mr-type isoforms decreased.

Effect of dizocilpine maleate on cerebral anoxia and ischemic damage in rodents

The Protective effects of dizocilpine maleate (DM) against anoxia in mice and ischemic damage in rats of 4-vessel occlusion (4-VO) were studied. DM 0.5 or 1.0 mg.kg-1 ip significantly prolonged the survival time of mice in closed containers. DM 0.5 and 1.0 mg.kg-1 ip 30 min prior to 4-VO obviously accelerated the electroencephalographic recovery, reduced the neuronal loss in the hippocampus, and increased the survival rate after 72-h reperfusion. These effects followed a dose-dependent manner. Our results indicate that selective non-competitive N-methyl-D-aspartate receptor blocker DM protects against anoxic and ischemic cerebral damage.

Effect of dizocilpine maleate on monoamines and their metabolites in rat brain

Systemic (ip) injection of dizocilpine maleate (DM, 0.1 and 0.5 mg.kg-1) increased the levels of 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid but did not bring about any noticeable change in the dopamine (DA) level in the striatum and limbic area. DM also increased the levels of norepinephrine in the limbic area and 5-hydroxyindoleacetic acid in the hippocampus. Amphetamine increased DA level and reduced DOPAC level in the striatum and limbic area. The behavioral manifestations revealed that DM predominantly evoked circling behavior and ataxia. The results indicate that the mechanism of the behavioral effect of DM may be different from that of amphetamine.

The pairing of the separated A and B chains of insulin and its derivatives, FTIR studies

From the amide I bands of their deconvolved FTIR spectra, the S-thiomethyl derivatives of the insulin A, B, despentapeptide(26-30) B and desoctapeptide(23-30) B chains all contain significant amounts of ordered secondary structure. The intact B chain is considerably more ordered than either the A or the truncated B chains. Comparison of the spectra of the separated and mixed intact chains of insulin suggests further folding upon mixing of the chains leading to significant increases in ordered secondary structures, presumably because of stabilization by interaction of the chains. The interactions of the A chain with the DPI B chain appear to be weaker as compared to that with the intact B chain. The above results suggest that only the intact A and B chains contain sufficient structural information to recognize each other and interact to form a native-like structure which make the correct formation of the disulfide linkages possible.

Effect of intrahippocampal quinolinic acid infusion on the amygdala kindling in rat

The effect of intrahippocampal infusion of quinolinic acid (Quin), an endogenous excitatory amino acid, was studied on the amygdala kindling. Quin 120 nmol injected intrahippocampally 2 wk prior to the beginning of amygdala kindling significantly not only produced dorsal hippocampal pyramidal and granule cell loss but also decreased the number of stimuli to trigger the stage 5 seizures of amygdala kindling. In kindled rats, intrahippocampal 20 nmol Quin infusion fully inhibited the stage 5 of amygdala-kindled seizures. The inhibitory effect of Quin was antagonized by dl-2-amino-7-phosphonoheptanoic acid, a selective antagonist of N-methyl-D-aspartate (NMDA) type receptors. The results suggest that NMDA-type receptors in the hippocampus may play a role in the control of the seizure threshold in the amygdala.

Identification and distribution of tropomyosin isoforms in chicken digestive canal

Two-dimensional gel electrophoresis of eight digestive organ extracts from 60-day-old chicks was performed. Judging from the similarity of their protein maps, the organs were classified into the following four types: 1) esophagus type, 2) proventriculus type, 3) gizzard type, and 4) intestine type. In four representative organs of these types, the distribution of tropomyosin isoforms was examined, and four high- and five low-Mr-type isoforms in addition to alpha and beta isoforms were detected in the embryonic organs. In the adult organs, however, there were three high- and four low-Mr-type isoforms, which were restricted to the mucous membrane, in addition to alpha and beta isoforms. Immunoblot analysis indicated that the high- and low-Mr-type isoforms in the embryo corresponded with those in the adult mucous membrane, but differences in the number and amount of the isoforms were found between the embryo and the adult mucous membrane.

Hysteroscopic hydrotubation for treatment of tubal blockage

In order to increase the effectiveness of hydrotubation, a plastic cannula was inserted into the fallopian tube under hysteroscopic control. Fifty women with tubal blockage confirmed by HSG were selected for treatment. Hydrotubation solution consisted of hydrocortisone (20 mg), gentamicin (160,000 IU) and procaine (80 mg) in 20 ml distilled water. Repeat HSG was performed. After three treatments, tubal patency (one or both tubes) was achieved in 20 women (40%), and seven pregnancies resulted within 1-18 months. Hysteroscopic hydrotubation may be an alternative treatment for tubal blockage.

[Spectrophotometric determination of micro-amounts of zinc in Gynostemma pentaphyllum (Thunb.) Makino]

1-(2-pyridylazo)-2-naphthol (PAN) and Emulsifier OP have been used in the colorimetric determination of zinc in Gynostemma pentaphyllum. The results are in agreement with those of atomic absorption spectrophotometry. The method is simple, precise and rapid. The recovery is 97.8-103.7% and coefficient of variation is 1.4-4.6%.

[Studies on the assimilation of inorganic selenium by yeast]

In the process of assimilation of inorganic selenium by yeast to the organic-selenium, some rules on the relation of the kinds of culture medium, concentration of sodium selenite and methionine to the total selenium and selenomethionine content in the yeast formed have been found; and a new, accurate procedure--modified acid hydrolysis-ion exchange chromatography for determining the content of seleno-amino acid in biological materials has been established.