Brassica napus pollen oleosins possess a characteristic C-terminal domain

The sequences of Brassica napus L. pollen oleosins have been determined and examined. Contrary to a recent report, inferred primary sequences of pollen oleosins do include a unique C-terminal domain characterised by the presence of a repetitive motif of three alanine and one proline residue (AAAP). This motif appears to be present in all oleosins expressed in pollen, but not in oleosins from other tissues.

ICD-10 mild cognitive disorder: epidemiological evidence on its validity

Criteria for the diagnosis of ICD-10 Mild Cognitive Disorder (MCD) were applied to a sample of 897 community dwelling elderly participants. Criterion A (the presence of a physical disorder) was met by 44%, Criterion B (report of a cognitive disorder) by 17%, Criterion C (an abnormality in quantified cognitive assessments) by 60%, and Criterion D (exclusion on basis of dementia and other conditions) by 74%. A total of 36 cases (4%) met all four criteria. Correlations between Criteria A and B, and B and C were weak (r = 0.18), and the correlation between Criteria A and C was almost zero (r = 0.02). This suggests that no syndrome exists. Membership of MCD was predicted by a report that memory or intelligence interfered with daily life but not by performance on cognitive tests or by a report of physical illness. Cases of MCD had higher anxiety, depression and neuroticism scores than normal elderly, but did not differ substantially on tests of cognitive functioning. These findings call into question the validity of the ICD-10 diagnosis of MCD.

Crocodile bites and traditional beliefs in Korogwe District, Tanzania

OBJECTIVES

To investigate why fatal crocodile bites are increasing in a Tanzanian district and the importance of traditional beliefs and superstitions in determining the residents' response to the crocodiles.

DESIGN

Information about beliefs was obtained by interview of Korogwe residents. Human and crocodile fatality statistics were obtained from the Korogwe Department of Natural Resources.

SETTING

Villages within Korogwe District.

SUBJECTS

Population of Korogwe District.

RESULTS

Crocodiles have been responsible for 51 deaths in the 52 months from January 1990 to April 1994. Of these, 18 deaths occurred in the first four months of 1994.

CONCLUSIONS

Local beliefs and superstitions about crocodiles include those about the taming of animals, with implications concerning the choice of victim and the penalties that may ensue if a crocodile is killed. The recent rise in human fatalities is thought to relate to increasing river pollution reducing the fish supply, together with a change in social mores at the riverside which has increased the crocodiles' displeasure. A reliable pumped water supply would reduce the need to draw water and bathe in the river, and eradication of superstition would empower the villagers in the fight against a common enemy.

A latent trait analysis of an inventory designed to detect symptoms of anxiety and depression using an elderly community sample

An 18-item inventory designed by Goldberg et al. (1987) to detect symptoms of anxiety and depression was administered to an elderly general population sample. Latent trait analysis was used to assess the dimensionality of the inventory and the location and discriminatory ability of the symptoms. The items showed different patterns of discrimination in this group compared to the sample of general practice attenders on which the inventory was developed. Overall, the items did define two correlated dimensions of anxiety and depression. In addition, a third dimension of sleep disturbance was detected. Both individual scales and the total symptom scores were sensitive and relatively specific detectors of depressive disorders assessed according to ICD-10 and DSM-III-R criteria. The retention of sleep items on their original scales did not affect the sensitivity of the scales to detect depressive disorders. A two-step administration procedure suggested for use in the administration of the scales was investigated but found to be sensitive to differences between the current sample and the sample on which the inventory was developed. This symptom inventory can be recommended for use in epidemiological investigations as a brief, valid and acceptable method of detecting elevated levels of anxiety and depression in elderly persons.

Role of the axial length/corneal radius ratio in determining the refractive state of the eye

The purpose of our study was to investigate the extent to which the ratio between axial length and corneal radius (the AL/CR ratio) determines the refractive state of the human eye. Subjects for the study were 194 young adults between the ages of 18 and 30 years, whose spherical equivalent refraction ranged from +7.91 to -13.32 D. For each subject, manifest objective refraction, corneal radii, and axial ocular distances were measured. Lens power was determined using a formula proposed by Bennett and Rabbetts. The AL/CR ratio was found to be approximately 3.00 for emmetropic eyes, ranging from 2.60 for the most highly hyperopic eye to 4.10 for the most highly myopic eye. The coefficient of determination of linear regression for the AL/CR ratio as a function of spherical equivalent refraction was 0.84, suggesting that 84% of the variance in refraction could be accounted for by variance of the AL/CR ratio. The results of the study suggest that for a given amount of ametropia, an eye having a relatively high AL/CR ratio would tend to have a low-powered lens (indicating that the lens had "emmetropized"), whereas an eye having a relatively low AL/CR ratio would tend to have a high-powered lens. We conclude that the AL/CR ratio can provide information concerning the extent to which the lens has emmetropized by reducing its power concurrent with axial elongation.

Apoptosis is not involved in the hypersensitivity of Fanconi anemia cells to mitomycin C

A striking feature of Fanconi anemia (FA) cells is their hypersensitivity towards crosslinking agents such as mitomycin C (MMC). In this study, we have shown that treatment of lymphoblastoid cells with MMC resulted in nuclear fragmentation, chromatin condensation, and DNA degradation, which is characteristic of apoptosis. The level of DNA fragmentation 48 hours after MMC treatment reached approximately 33% in both control and FA cells. In addition, 24 hours after drug addition a decrease in the number of cells in the G2/M phase of the cell cycle was seen. This coincided with the appearance of apoptotic cells in the sub-G1 phase, indicating that once the cells had passed through G2/M, apoptosis occurred. The number of apoptotic cells increased to 60% 96 hours after MMC treatment. The number of apoptotic cells increased to 60% 96 hours after MMC treatment. The onset and level of apoptosis was found to be identical in FA and control cell lines, indicating that the FA defect does not lead to abnormal apoptotic cell death.

Colorectal cancer: lessons for genetic counselling and care for families

Cancers of the colon and the rectum are the second leading cause of malignancy in European countries with similar incidence rates for men and women and, therefore, one of the major health concerns. Emphasis is placed on the early detection of a developing neoplasm in order to improve the life expectancy of patients and their quality of life. Colorectal cancer (CRC) is an excellent model for studying the etiology and pathogenesis of a common malignancy and the complex multistage process of carcinogenesis. Abundant clinical and pathological evidence suggests that CRC arises from benign adenomas that proceed through a series of steps to metastatic carcinomas. Following the discovery of oncogenes and, more importantly tumor suppressor genes, Fearon & Vogelstein (1990) proposed a scheme of genetic events which are associated with colorectal tumorigenesis. Genetic linkage studies have recently identified another type of gene for colon cancer susceptibility that seems to act by destabilising the genome.

Perceptual accuracy as measured by the Rorschach: are American norms applicable for cross-cultural assessment?

Cross-cultural applications of Rorschach's test assume that American norms may be applied, but this assumption has little empirical basis. In fact, several such investigations have indicated that culture-specific norms must be employed on key variables employed to assess subjects' perceptual accuracy. The current study compared responses of 19 Spanish children who scored low on a reading measure and were considered by their teachers to experience significant reading problems with 19 peers who scored significantly higher on that reading measure and who experienced no apparent reading problems. Perceptual accuracy of both groups, as measured by the F+ and X+ percents, was virtually identical. Results are discussed in the context of other research which has questioned the cross-cultural applicability of American norms with respect to perceptual accuracy.

Cathepsin G: localization in human cerebral cortex and generation of amyloidogenic fragments from the beta-amyloid precursor protein

Amyloid deposits in Alzheimer's disease, Down's syndrome and aged brain are composed largely of A beta protein, which is generated by proteolytic processing of beta-amyloid precursor protein. Proteases responsible for liberating the A beta protein from the precursor have not yet been identified. Here, we examined the ability of cathepsin G, a chymotrypsin-like protease, to cleave two protease substrates: (i) a fluorogenic hexapeptide, whose sequence spans the cleavage site in the precursor for generating the A beta NH2-terminus, and (ii) recombinant human beta-amyloid precursor protein purified from a baculovirus expression system. Unlike two other members of the chymotrypsin family, cathepsin G readily degraded the hexapeptide. Furthermore, cathepsin G cleaved the beta-amyloid precursor protein to generate several breakdown products, including a prominent 11,500 mol. wt fragment immunoreactive with antibodies directed against the COOH-terminus of the protein. This COOH-terminal fragment co-migrated using two-dimensional isoelectric focusing/sodium dodecyl sulfate-polyacrylamide gel electrophoresis with C-100, a recombinant COOH-terminal segment of the beta-amyloid precursor, whose NH2-terminus is one residue upstream of the NH2-terminus of the A beta domain. We also examined the localization of cathepsin G in human brain. The distribution of cathepsin G-containing cells was examined by immunohistochemistry in the temporal cortex of both Alzheimer's and aged control samples. Cathepsin G-like immunoreactivity was contained specifically within neutrophils. As visualized by double-labeling with antibodies to cathepsin G and Factor VIII, neutrophils were most frequently found within meningeal or cortical blood vessels. In addition, occasional neutrophils could be identified without an apparent vascular surround, in the brain parenchyma. By simultaneous labeling with antibodies to cathepsin G and A beta protein, neutrophils were also sometimes found associated with both parenchymal and vessel amyloid deposits; however, these associations were rare. These findings indicate that cathepsin G is capable of cleaving the beta-amyloid precursor protein to liberate the free NH2-terminus of the A beta protein and may have access to areas where this material is deposited in Alzheimer's disease. However, since there is no physical association between neutrophils and deposited amyloid and no increase in the number of neutrophils in an Alzheimer's brain, cathepsin G seems to be an unlikely mediator of amyloid deposition in this disease.

Complaints of cognitive decline in the elderly: a comparison of reports by subjects and informants in a community survey

In a community survey, subjects and their informants were asked the same questions about memory and intellectual decline in the subjects. Subjects and informants both commonly reported cognitive decline, although in most cases the decline was not seen as interfering with daily life. However, when responses from subjects and informants were cross-tabulated, agreement was found to be poor. For subjects, reports of cognitive decline were correlated with anxiety and depression symptoms and with trait neuroticism. Subjects' reports were uncorrelated with age and only weakly correlated with cognitive test performance, indicating little validity. By contrast, informants' reports were correlated with the subjects' cognitive test performance and age, but also with the informants' own anxiety and depression symptoms. Although informants' reports have validity, they may also be contaminated by the informants' affective state.

Risk factors for the development of glaucomatous visual field loss in ocular hypertension

OBJECTIVE

To detect characteristics of persons with ocular hypertension that are associated with a higher risk of future glaucomatous field loss.

METHODS

Annual examinations of the optic disc, nerve fiber layer, and visual field in 647 persons with bilateral intraocular pressure higher than 21 mmHg and initially normal visual field test results with the Goldmann perimeter.

RESULTS

Sixty-eight persons developed a field defect on two consecutive Goldmann visual field tests in at least one eye, while 579 others retained normal fields. Moderate or severe nerve fiber layer atrophy at baseline was associated with a seven to eight times greater risk of development of visual field loss. Attributes that were significantly associated with the incidence of field loss included older age, larger cup-disc ratio, smaller rim-disc area ratio, larger cup asymmetry, presence of disc crescent, and higher intraocular pressure. Characteristics found not to be associated with incidence were gender, race, hypertension, diabetes, refractive error, family history of glaucoma, smoking or alcohol drinking history, and disc area.

CONCLUSIONS

Increasing nerve fiber layer atrophy judged by a semiquantitative grading system was associated with increasing risk of development of visual field loss among persons with ocular hypertension. The relationship of the development of field loss to race, myopia, family history of glaucoma, and medical history are more complex than has been presumed.

In vivo production of tumour necrosis factor-alpha and interleukin-6 in BALB/c mice inoculated intranasally with a high dose of respiratory syncytial virus

Intranasal administration of an inoculum of 10(7) focus-forming units (FFU) of respiratory syncytial (RS) virus induced disease in BALB/c mice with signs of anorexia, cachexia, ruffled fur, and pneumonia. Mice displayed mild signs of illness on day 1 postinoculation (PI), followed by a transient recovery phase of 3 days. Disease rapidly reappeared on day 5 PI and worsened on subsequent days, with mortalities by day 7 PI. Mice inoculated with 5 x 10(6) FFU exhibited milder signs of disease, while those inoculated with 2 x 10(6) FFU and control mice given only Hep-2c cell suspension exhibited no noticeable signs of illness. High levels of bioactive tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) were detected in both lungs and sera of mice inoculated with 10(7) FFU of virus. Peak levels of both cytokines were detected at day 1 PI but remained detectable throughout the 7 day period studied postinoculation. Cytokine levels were much lower or were undetectable in control mice. These results suggest that the macrophage is stimulated in vivo to produce inflammatory cytokines in response to RS virus infection.

Do mental health surveys disturb? Further evidence

In a community survey of 873 persons aged 70 years or over, focusing on dementia, cognitive decline, depression, and current life circumstances, we included an enquiry into the emotional impact of the interview. A large majority reported at the end of the interview that it had no adverse effect on their emotional state. About 4% reported that it made them distressed, 1% that it depressed them, and 2% that it had intruded on their privacy. By contrast, 52% said it had made them feel good about themselves. Distress seemed to be largely related to performing poorly on cognitive tests. There is no information on the duration of these effects in the period following the interview. It is recommended that respondents in community surveys, including the elderly, be informed that they can decline to answer any question, and that interviewers be trained in how to respond to the few who will be distressed by the experience.

Wear debris from bipolar femoral neck-cup impingement. A cause of femoral stem loosening

The source of wear debris in total hip arthroplasty may occur at various interfaces: metal-ultra-high molecular-weight polyethylene bearings, metal-cement micromotion, bone-cement interfaces, and implant coatings. Wear-induced osteolysis may result in a spectrum of radiographic changes from radiolucent lines to massive osteolysis. Subsequent loosening of the implant may occur and revision may be difficult because of bone deficiencies. Impingement of the femoral neck on the acetabular component may result in polyethylene and/or metal debris, leading to early femoral stem loosening. The five cases presented, involving six hips, illustrate how bipolar cup-stem impingement may result in significant wear-induced femoral osteolysis.

Identification of a metalloprotease from Alzheimer's disease brain able to degrade the beta-amyloid precursor protein and generate amyloidogenic fragments

A 4.2-kDa polypeptide termed beta protein (A beta) accumulates in senile plaques and blood vessels in Alzheimer's disease and Down's syndrome. It is widely believed that A beta is the product of the posttranslational processing of a larger precursor protein, the beta amyloid precursor protein (APP). The proteolytic processes involved in the generation of the A beta are virtually unknown. Here the purification and characterization of a protease from Alzheimer's disease brain capable of cleaving a 10 amino acid synthetic substrate flanking the N terminus of A beta at the Met-Asp bond are described. Most importantly, the purified protease degrades human recombinant APP and generates a 15-kDa amyloidogenic fragment. The protease requires the presence of a reducing agent for its activity. Its pH optimum is around physiological pH, while the enzyme is inactive at acidic pH (below pH 5.0) and basic pH (over pH 7.6). The enzyme is inhibited by N-ethylmaleimide, (hydroxymercuri)benzoate, 1.10-phenanthroline, EDTA, and EGTA. Phenylmethanesulfonyl fluoride has no effect on its activity. This protease is devoid of caseinolytic or gelatinase activities, as well as activities against cathepsin B and cathepsin L substrates. Sequence analysis reveals high homology to the rat metallopeptidase EC 3.4.24.15, a protease involved in neuropeptide processing.

The highly expressed tapetum-specific A9 gene is not required for male fertility in Brassica napus

An antisense approach was used to attempt to determine the function of the highly abundant, tapetum-specific A9 transcript in microsporogenesis. A Brassica napus A9 cDNA clone was linked in sense and antisense orientations to the Arabidopsis thaliana A9 promoter and the resulting chimaeric genes introduced into B. napus. A high proportion of the offspring of B. napus antisense A9 plants had very low or undetectable levels of A9 mRNA. However, these plants set seed and had pollen of normal or near normal viability. Therefore, under the conditions studied, the A9 protein appears not to be essential for male fertility in B. napus.

Penetration of human spermatozoa through the zona pellucida of nonviable human oocytes

OBJECTIVE

The purpose of this study was to evaluate the penetrating capacity of human sperm through the intact zonae of nonviable human oocytes and the influence of oocyte storage conditions and gamete coincubation times on penetration rates.

METHODS

Immature oocytes were obtained from surgically removed ovarian tissue and from in vitro fertilization (IVF) and subjected to four storage conditions: 1) storage at 4 degrees C for up to 48 hours in culture medium (refrigeration, n = 53), 2) cryopreservation in 1.5 mol/L propanediol with storage at -196 degrees C (PrOH; n = 49), 3) cryopreservation in 2.0 mol/L dimethylsulfoxide with storage at -70 degrees C (DMSO; n = 20), and 4) storage in a hypertonic salt solution at 4 degrees C (salt; n = 30). Semen was obtained from fertile donors (n = 7) and after a wash and swim-up, samples were adjusted to 500,000 motile sperm/mL. Zonae and sperm were coincubated in 100-microL drops under oil, and penetration was assessed at 5 and 20 hours. Penetration was evidenced by visualization of at least one sperm head in the perivitelline space at 200x magnification.

RESULTS

Zona penetration rates were 50.9, 32.7, 23.3, and 10.0% for refrigeration, PrOH, salt, and DMSO storage, respectively (P < .004). There was a significantly higher number of sperm in the perivitelline space after 20 hours' coincubation (3.8 +/- 0.2) compared to 5 hours (0.8 +/- 0.1) (P < .0006). This represented an increase in the penetration rate from 31.2% (34 of 109) at 5 hours to 37.6% (41 of 109) at 20 hours, although the difference was not significant.

CONCLUSIONS

These results demonstrate that the zona pellucida of nonviable human oocytes can be used in a zona penetration assay and that refrigerated and PrOH-frozen intact zonae have the highest rates of penetration. The decrease in penetrability seen in DMSO and salt-stored oocytes may be due to alterations occurring in the zona pellucida.

Quantitative grading of nerve fiber layer photographs

PURPOSE

The authors have developed a simple method for semi-quantitative grading of atrophy of the peripapillary nerve fiber layer (NFL) in black and white photographs.

METHODS

An experienced observer read sets of NFL photographs using a four-level grading system. Five observers with varying levels of experience at ophthalmic examination were taught the grading system in approximately 4 hours, and their readings were compared with those of the expert.

RESULTS

The reproducibility of readings by an experienced observer was excellent. The validity of the grading system was confirmed by comparisons to visual field findings, as well as to cup-to-disc ratios in the same eyes. The agreement with the expert by the five trained graders was good.

CONCLUSIONS

Grading of the NFL could be useful both to monitor development of early glaucoma damage clinically and to measure progression of glaucoma damage in clinical trials research. The grading system can be taught readily to other observers.

The anther-specific protein encoded by the Brassica napus and Arabidopsis thaliana A6 gene displays similarity to beta-1,3-glucanases

An anther-specific Brassica napus cDNA, A6, and two corresponding Arabidopsis thaliana genes have been isolated. Sequence analyses of A6 revealed similarity to beta-1,3-glucanases. The deduced A6 protein differs from other beta-1,3-glucanases in the possession of a long C-terminus. Immunoblotting using an antibody raised to the A6 protein detects a temporal 60 kDa protein in B. napus buds, suggesting that the long C-terminal region is present in the mature protein. A6 promoter-GUS and RNase fusions demonstrate that the A6 gene is tapetum-specific and temporally expressed with a peak in activity when the plant normally expresses callase (a complex of endo- and exo-beta-1,3-glucanase activities). The sequence similarity of A6 to other beta-1,3-glucanases, coupled with the temporal and spatial expression data, suggests that A6 may be part of the callase enzyme complex.

Case report: malignant giant cell tumour of the pancreas presenting as a large pancreatic cyst

Carcinoma of the pancreas is a common tumour. Histologically, the majority are adenocarcinomas of duct origin. Carcinomas of the pancreas containing giant cells are uncommon and those containing osteoclast-type tumour cells are very rare. We report a case of malignant giant cell tumour presenting as an extremely large, thin walled haemorrhagic cyst of the pancreas. This tumour is most unusual in that the wall is composed of multiple highly pleomorphic malignant-looking multinucleated giant cells as well as numerous osteoclast-like giant cells in a stroma of small spindle shaped mononuclear cells.

Induction and removal of interstrand crosslinks in the ribosomal RNA genes of lymphoblastoid cell lines from patients with Fanconi anemia

The repair of interstrand crosslinks has been investigated in Fanconi anemia (FA) and normal cells as there is evidence suggesting that FA patients have a defect in DNA repair. Lymphoblasts were treated with the crosslinking agent mitomycin C (MMC) and the removal of the induced DNA lesions investigated at the level of the actively transcribed ribosomal RNA (rRNA) genes. MMC-induced crosslinks appeared to be a rather stable lesion in the rRNA genes for all cell lines studied. Variable repair efficiencies were found between the different cells lines but they could not be used to distinguish normal cells from FA cells. Therefore, we propose that the specific sensitivity of FA cells towards MMC cannot be directly correlated with a deficient repair in interstrand crosslinks and that probably the complexity of the repair process is greater than previously described.