Traumatic amnesia, repression, and hippocampus injury due to emotional stress, corticosteroids and enkephalins

The role of stress, arousal, emotional trauma, and corticosteroid and enkephalin secretion on memory and the hippocampus, and the development of traumatic amnesia and repressed memory syndrome are detailed. Animal and human studies are reviewed. Trauma-induced memory deficits appear to be secondary to abnormal neocortical and hippocampal arousal, and corticosteroid and enkephalin secretion which can induce atrophy or seizures within the hippocampus, suppress hippocampal theta activity and long term potentiation, as well as injure hippocampal pyramidal cells. Predisposing factors include individual, age, and sex differences in arousal, and previous emotional trauma or temporal lobe or hippocampal injury. However, as the amygdala processes and stores emotional experiences in memory, patients may also demonstrate trauma related symptoms, including flashbacks as well as shrinking retrograde amnesia.

Anteriomesenteric duodenal compression syndrome

We report the case of a 48 year old man who presented with a 4 month history of vomiting and weight loss. Barium studies and upper gastrointestinal endoscopy demonstrated anteriomesenteric duodenal occlusion. We discuss the possible aetiology and significance of his investigation findings and subsequent management.

Reducing cervical cancer among First Nations women

First Nations women in British Columbia have a four to six times higher mortality rate from cancer of the cervix than do women in the general population. Their participation in the provincial Cervical Cytology Screening Program (CCSP) is less regular and less frequent than other women in B.C. Likewise, they have more difficulty in obtaining culturally suitable health care services from respectful and consistent professionals. These issues should be of critical concern to nurses, as nurses provide the majority of health services to First Nations people.

Nutritional quality of lactic fermented bitter gourd and fenugreek leaves

Pediococcus pentosaceus was selected from isolates obtained from the naturally fermenting bitter gourd and fenugreek leaves based on its high titre and broad spectrum of inhibitory activity against spoilage organisms. This strain was then employed for fermentation of bitter gourd and fenugreek which resulted in a more acceptable product having enhanced fat, pyridoxine and ascorbic acid levels. It was of interest to note that vitamin B12 was formed in the fenugreek as a result of the fermentation.

Genetic variability and diversity for protein and calcium contents in finger millet (Eleusine coracana (L.) Gaertn) in relation to grain color

Analysis of 36 genotypes of finger millet (Eleusine coracana (L.) Gaertn) with varying seed colors revealed a wide range of protein and calcium contents. White seeded genotypes had higher protein contents, while brown seeded types had a wide range of values. The brown seeded genotype GE 2500 had the highest protein content. Although protein content had significant negative association with calcium content, white seeded types had moderate levels of calcium. The genotypic coefficients of variability were moderate and high for protein and calcium, respectively. High heritability coupled with high genetic advance indicated their governance by additive gene action. A negative significant correlation was observed between protein content and grain yield. Mahalanobis D2 analysis grouped the 36 genotypes into eight clusters. Clustering pattern failed to indicate any relationship between genetic diversity and geographic diversity. Based on genetic diversity and performance, the genotypes MS 1168, MS 174 and CO 13 were found to be suitable for use as parents in a hybridization program for improving yield; the genotypes MS 1168, MS 174 and MS 2869 for protein and Malawi 1915 and CO 11 for calcium. Protein and calcium contents contributed less to genetic divergence.

Effects of aspirin on platelet aggregation in smokers and nonsmokers

OBJECTIVE

To assess the relative antiaggregatory ability of aspirin on platelets of smoking and nonsmoking healthy volunteers.

DESIGN

Prospective, randomized, crossover study.

SETTING

Tertiary-care teaching institution.

SUBJECTS

Eighteen healthy smoking and nonsmoking male volunteers.

INTERVENTIONS

Each subject received aspirin 325 mg or ticlopidine 250 mg bid as an active control for 7 days in a crossover manner separated by a 1-month washout period. Whole blood platelet aggregation was measured on four occasions, twice at baseline and once after each drug treatment.

OUTCOME MEASUREMENT

Whole blood ex vivo platelet aggregation in terms of impedance (omega) and adenosine triphosphate (ATP) release (nmol), as assessed using Lumi-aggregometry.

RESULTS

Aspirin was associated with significantly less ATP release in both smokers (p = 0.01) and nonsmokers (p = 0.003). No significant differences in platelet aggregation were found between smokers and nonsmokers at baseline or with any treatment phases. Sixty-seven percent and 17% of volunteers receiving ticlopidine and aspirin, respectively, reported adverse effects.

CONCLUSIONS

Twice-daily administration of aspirin for 7 days to healthy volunteers was well tolerated and also reduced platelet aggregation significantly regardless of smoking status.

Recognition and treatment of reactions to contrast media: a model for resident and faculty education employing lectures and case scenario workshops

RATIONALE AND OBJECTIVES

The effectiveness of an interactive course on the recognition and treatment of contrast media reactions was studied.

METHODS

An instructional course on contrast media reactions was organized for the radiology staff, residents, and nurses. Before the beginning of the 3-day course, a 25-point pretest was administered to determine the ability of each participant to recognize and treat contrast material reactions. An identical posttest was administered after the course, and the pre- and posttest results were compared.

RESULTS

There was a statistically significant improvement on the posttest scores for all subjects tested (P < .05). There was also a substantial improvement in the participants' confidence levels in dealing with contrast media reactions.

CONCLUSIONS

A short course on contrast material reactions is a worthwhile learning aid that is simple to conduct and educates and instills confidence in both residents and staff.

Effect of amine activators on the properties of chemical cured dental composites

The purpose of this study was to evaluate the reactivity and the effect of concentration of three tertiary amines upon the mechanical properties of a chemical curing dental composite. Chemical cured composite pastes were prepared by keeping peroxide concentration constant at 1 wt% (by weight of resin mixture) and by varying the amine/peroxide molar ratio from 0.25 to 1.5. Composite samples were prepared for all three amine pastes aged for 1, 15, 30, 45, and 60 d stored at 8, 22, and 37 degrees C. The loss in activity of the tertiary amine with time was measured. Changes in compressive strength, diametral tensile strength, and microhardness were also measured. A sharp decrease in working and setting times corresponding to increased activity was noticed with an increased amine content. The activity was found to vary in the order N,N-dimethyl p-toluidine (DMPT) > 2-(4-dimethylaminophenyl)ethanol (DMAPEA) > N,Ndiethanol p-toluidine (DEPT). DMPT is found to be more temperature sensitive than DMAPEA and DEPT. However, DEPT is found to provide better storage stability out of all three amines tested. Each amine was found to possess optimum concentrations at which the mechanical properties showed maximum values. DEPT is preferred for long-term storage stability in chemical-cured dental composites where aging tends to reduce the activity of the amine.

Effect of phototherapy on thyroid stimulatory hormone and free thyroxine levels

OBJECTIVE

To study the effect of phototherapy for neonatal hyperbilirubinaemia on thyroid function as neonatal thyroid screening is sometimes performed during exposure to phototherapy.

METHODOLOGY

Infants with non-haemolytic hyperbilirubinaemia were sequentially allocated to fibre-optic phototherapy, conventional daylight phototherapy, or a combination of both. Bilirubin concentration was monitored 12 hourly by capillary blood sampling; venous blood was sampled for thyroid stimulating hormone (TSH) and free thyroxine (fT4) determinations, at start of exposure, at 24 h, end of exposure and 1 day later. Comparable unexposed infants served as controls.

RESULTS

All 123 study infants and 25 controls remained well during the study. Bilirubin levels declined during phototherapy, being most rapid in the combination group. The TSH and fT4 values at start of exposure were 3.86 +/- 0.41 mU/L (mean +/- SEM) and 33.20 +/- 1.16 pmol/L, respectively, in the fibre-optic group, 3.62 +/- 0.38 mU/L and 37.22 +/- 1.76 pmol/L in the daylight group, and 4.40 +/- 0.48 mU/L and 29.91 +/- 1.13 pmol/L in the combined group, compared with 5.77 +/- 0.40 mU/L and 34.46 +/- 1.68 pmol/L in the control group. The TSH and fT4 values declined with increasing age in the phototherapy and control groups with end of exposure values of 2.90 +/- 0.28 mU/L and 27.71 +/- 0.71 pmol/L, 2.77 +/- 0.31 mU/L and 33.52 +/- 1.22 pmol/L, and 3.44 +/- 0.30 mU/L and 27.54 +/- 0.88 pmol/L, respectively, compared with 4.21 +/- 0.61 mU/L and 27.19 +/- 2.33 pmol/L (at 72 h) in the control group. The pattern of TSH and fT4 decline in the exposed and control groups was similar, being related to increasing age.

CONCLUSIONS

The validity of neonatal thyroid screening is not affected by fibre-optic or conventional phototherapy or by both combined.

Neuronatin mRNA in PC12 cells: downregulation by nerve growth factor

Neuronatin was recently cloned from neonatal rat brain (Biochem, Biophys. Res. Commun., 201 (1994) 1227-1234). In subsequent studies, we noted neuronatin mRNA was brain-specific and that there were two alternatively spliced forms, alpha and beta (Brain Res., 690 (1995) 92-98). Furthermore, on sequencing the human neuronatin gene, it was determined that the alpha-form was encoded by three exons, and the beta-form was encoded by the first and third exons only (Genomics, 33 (1996) 292-297). The middle exon was spliced out in the beta-form. The human neuronatin gene is located in single copy of chromosome 20q 11.2-12 (Brain Res., 723 (1996) 8-22). These studies called for an understanding of the function of this gene. Therefore, we studied the expression of neuronatin in PC12 cells, an established model of neuronal growth and differentiation. Neuronatin mRNA expression was found to be abundant in undifferentiated PC12 cells. Treatment with nerve growth factor (NGF), resulting in neuronal differentiation, was associated with a downregulation of neuronatin mRNA expression. Removal of NGF was associated with a return of neuronatin mRNA levels towards baseline. These effects appear to be specific for NGF as they were not seen with transforming growth factor, epidermal growth factor, 12-O-tetradecanoylphorbol-13-acetate or dexamethasone. Although, basic fibroblast growth factor also reduced neuronatin mRNA levels, the effect was less pronounced than with NGF. The NGF-induced decreased in neuronatin mRNA occurred even in the presence of protein and RNA syntheses inhibitors. Of the two spliced forms, only the alpha-form was expressed in PC12 cells. In conclusion, we report the presence of neuronatin mRNA in PC12 cells, and that NGF downregulates its expressions. These findings provide a basis for investigating the role of neuronatin in neuronal growth and differentiation.

Cervical cytology screening. How can we improve rates among First Nations women in urban British Columbia?

OBJECTIVE

To determine Pap smear screening rates among urban First Nations women in British Columbia; to identify facilitators and barriers; and to develop, implement, and evaluate specific interventions to improve Pap smear screening in Vancouver.

DESIGN

Computer records of band membership lists and the Cervical Cytology Screening Program registry were compared to determine screening rates; personal interviews and community meetings identified facilitators and barriers to urban screening programs. A community advisory committee and the project team collaborated on developing specific interventions.

SETTING AND PARTICIPANTS

Purposive sample of British Columbia First Nations women, focusing on women living in Vancouver.

INTERVENTIONS

Poster, art card, and follow-up pamphlet campaign; articles in First Nations community papers; community meetings; and Pap smear screening clinics for First Nations women.

MAIN OUTCOME MEASURES

Pap smear screening rates among BC First Nations women according to residence and reasons for not receiving Pap smears.

RESULTS

Pap smear screening rates were substantially lower among First Nations women than among other British Columbia women; older women had even lower rates. No clear differences were found among First Nations women residing on reserves, residing in Vancouver, or residing off reserves elsewhere in British Columbia. Facilitators and barriers to screening were similar among women residing on reserves and in Vancouver. Many First Nations women are greatly affected by health care providers' attitudes, abilities to provide clear information, and abilities to establish trusting relationships.

CONCLUSIONS

Family physicians are an important source of information and motivation for Pap smear screening among First Nations women.

Cloning of human neuronatin gene and its localization to chromosome-20q 11.2-12: the deduced protein is a novel "proteolipid'

Human brain development is a continuum governed by differential gene expression. Therefore, we proceeded to identify genes selectively expressed in the developing brain. Using differential display and library screening, a novel rat cDNA, neuronatin, was identified and used to screen a human fetal brain cDNA library. Human neuronatin cDNA was isolated and sequenced. The cDNA was 1159 bp long and corresponded in size to the 1.25 kb message detected on Northern analysis. Neuronatin mRNA was selectively expressed in human brain during fetal development, but became repressed in adulthood. When studied in the rat, neuronatin mRNA first appeared at mid-gestation in association with the onset of neurogenesis, becoming most pronounced later in development when neuroepithelial proliferation and neuroblast commitment are manifest, and declined postnatally coinciding with the completion of neurogenesis. The deduced protein has two distinct domains, a hydrophobic N-terminal and basic C-terminal rich in arginine residues. Both the amino acid sequence and secondary structure of this amphipathic polypeptide exhibited homology to PMP1 and phospholamban, members of the "proteolipid' class of proteins which function as regulatory subunits of membrane channels. The neuronatin gene, 3973 bases long, contains in its 5'-flanking region a neural restrictive silencer element which may govern neuron-specific expression. Based on screening a somatic cell hybrid panel, neuronatin gene was assigned to chromosome-20. And, using deletion constructs of chromosome-20 and fluorescence in situ hybridization, neuronatin was localized to chromosome-20q11.2-12. In conclusion, neuronatin is a novel human gene that is developmentally regulated and expressed in the brain. The deduced protein is a proteolipid that may function as a unique regulator of ion channels during brain development. The definitive localization of neuronatin to human chromosome 20q11.2-12 provides the basis to investigate this gene as a candidate in neuro-developmental diseases that may also map to this region.

Structure and organization of the human neuronatin gene

Neuronatin is a brain-specific human gene that we recently isolated and observed to be selectively expressed during brain development. In this report, the genomic structure and organization of human neuronatin is described. The human gene spans 3973 bases and contains three exons and two introns. Based on primer extension analysis, a single cap site is located 124 bases upstream from the methionine (ATG) initiation codon, in good context, GAACCATGG. The promoter contains a modified TATA box, CATAAA (-27), and a modified CAAT box, GGCGAAT (-59). The 5'-flanking region contains putative transcription factor binding sites for SP-1, AP-2 (two sites), delta-subunit, SRE-2, NF-A1, and ETS. In addition, a 21-base sequence highly homologous to the neural restrictive silence element that governs neuron-specific gene expression is observed at -421. Furthermore, SP-1 and AP-3 binding sites are present in intron 1. All splice donor and acceptor sites conformed to the GT/AG rule. Exon 1 encodes 24 amino acids, exon 2 encodes 27 amino acids, and exon 3 encodes 30 amino acids. At the 3'-end of the gene, the poly(A) signal, AATAAA, poly(A) site, and GT cluster are observed. The neuronatin gene is expressed as two mRNA species, alpha and beta, generated by alternative splicing. The alpha-form contains all three exons, whereas in the beta-form, the middle exon has been spliced out. The third nucleotide of all frequently used codons, except threonine, of neuronatin is either G or C, consistent with codon usage expected for Homo sapiens. This information about the structure of the human neuronatin gene will help in understanding the significance of this gene in brain development and human disease.

Comparison of methods for measuring albumin in peritoneal dialysis and hemodialysis patients

Serum albumin levels have been used extensively as an indicator of morbidity in patients with end-stage renal disease. Recent evidence suggests that albumin levels vary considerably in hemodialysis patients depending on the laboratory method used, but formulas for comparing albumin values by different methods have not been developed. We prospectively evaluated the effects of measuring albumin by three different methods on paired plasma and serum from 23 patients on continuous ambulatory peritoneal dialysis (CAPD) and 53 patients on chronic maintenance hemodialysis. Plasma and serum gave virtually identical results independent of method used. In CAPD patients, bromcresol green and nephelometry gave nearly identical albumin measurements through the entire range of plasma levels. In contrast, bromcresol purple gave values that were 9.9 percent +/- 1.3 percent lower (P < 0.05). Hemodialysis patients showed a similar pattern with close agreement between bromcresol green and nephelometry, but bromcresol purple gave lower albumin levels by 19.1 percent +/- 1.2 percent (P < 0.05). The discrepancy in albumin in CAPD patients was significantly less than in the hemodialysis patients (P < 0.05), suggesting that there were fewer interfering substances in the blood of CAPD patients than in hemodialysis patients. Linear regression analysis was used to develop simple formulas for comparing albumin values obtained by the different methods in CAPD and hemodialysis patients. These studies show that values for albumin in blood vary significantly by method of analysis in CAPD and hemodialysis patients. By the use of these formulas, it becomes possible to compare albumin values between centers using different methods for the purpose of quality management.

Fetal and neonatal haemodilution associated with multiple placental chorioangioma: case report

A pregnancy with polyhydramnios and abnormal antepartum fetal heart rate pattern was found to have multiple placental haemangiomas. Multiple placental haemangiomas can give rise to fetal cardiac failure due to a hyperdynamic circulation or fetal anaemia either due to haemodilution or possibly destruction of blood cells in the chorioangioma. Whether fluid restriction with or without diuretics or blood transfusion is the correct form of treatment of neonatal cardiac failure in such a case is discussed.

Neuronatin mRNA: alternatively spliced forms of a novel brain-specific mammalian developmental gene

Neurogenesis begins with the closure of the neural tube around mid gestation and continues in the rat for about two weeks postnatally. Therefore, we investigated the role of neuronatin, a novel cDNA that we cloned from neonatal rat brain (Joseph et al., Biochem. Biophys. Res. Commun., 201 (1994) 1227-1234), in brain development. Further studies described in the present manuscript, lead to the identification of two alternatively spliced forms of neuronatin mRNA, alpha and beta, with the same open reading frame. Neuronatin-alpha encoded a novel protein of 81 aa, and the beta-form encoded 54 aa. Both forms were identical, except that the alpha-form had an additional 81 bp sequence inserted into the middle of the coding region. On Northern analyses, neuronatin mRNA was relatively selective for the brain. It first appeared at E11-14, a time when the neural tube has closed and neuroepithelial proliferation initiated, became pronounced at E16-19 with a surge in neurogenesis, and declined postnatally to adult levels with the completion of neurogenesis. In order to determine whether there were other forms of neuronatin mRNA, and to study the expression of the alpha and beta forms separately during development, reverse transcriptase-polymerase chain reaction was carried out using primers flanking the coding region of the alpha and beta forms. The RT-PCR results clearly indicated that there were only two forms of neuronatin. The beta-form first appeared at E11-14, whereas the alpha-form was present even earlier at E7-10. Together, these findings indicate that the two forms of neuronatin mRNA are regulated differently during brain development.(ABSTRACT TRUNCATED AT 250 WORDS)

Unusual biphasic melting behaviour of Rhodotorula gracilis DNA

Ultraviolet, fluorescence and CD spectral analysis suggested unusual structural features of Rhodotorula gracilis ATCC 90950 DNA. R. gracilis DNA exhibited 13% hyperchromicity at 260 nm as against 26% shown by calf thymus DNA. The biphasic melting curve, one phase between 88-92 degrees C and the other between 92-97 degrees C, was attributed to different unwinding pattern of R. gracilis DNA as a function of rise in temperature. The binding affinity of ethidium bromide to R. gracilis DNA determined was almost the same as that of calf thymus DNA. Fluorescence spectra with rise in temperature showed decrease in the quanta of fluorescence intensity after transition temperature, suggesting the quenching due to variation in structure. The CD spectra of R. gracilis DNA did not resemble the spectra of any of the known DNA forms and it showed increase in the magnitude of negative band with rise in temperature suggesting a B-C transition. Disruption of intermolecular and higher order structures by sonication and salt concentration did not change this behaviour implicating the influence of sequence and base composition of R. gracilis DNA on thermal melting transition.

p23 transplantation antigen mRNA is differentially expressed in human fetal brain

As gene expression governs development, we attempted to isolate differentially expressed genes in fetal and adult human brain. RNA samples extracted from adult and 18-24-week-old fetal human brain were reverse transcribed, amplified using twenty combinations of 3'-anchored primers and degenerate 5'-primers, and the resulting cDNA fragments separated on denaturing polyacrylamide gels. Thereafter, 45 (H1-H45) differentially displayed cDNA bands were extracted from the gels, amplified by polymerase chain reaction, and used as probes to detect their mRNA by northern blotting. One of these fragments, H8, confirmed on northern blotting to be highly expressed in fetal brain, was cloned and sequenced. This fragment was homologous to wild type p23 human transplantation antigen. This is phylogenetically a well conserved gene and appears to play an important role in cell growth. Even a single point mutation in the mouse gene results in cell destruction secondary to a cytotoxic T-lymphocyte response. Therefore, our finding that normal human fetal brain expresses high levels of wild type p23 transplantation antigen may have importance in maintaining cell growth during human brain development.

Prospects for the secondary prevention of colorectal cancer: screening by flexible sigmoidoscopy?

It may be useful to draw an analogy between the proposed screening programme for colorectal cancer and the cervical cancer screening programme. Both tumours show a spectrum of histological abnormalities consistent with a premalignant phase. The natural history of these premalignant lesions is poorly understood and although some will progress, if untreated, to invasive disease, most will not. Light microscopy cannot confidently distinguish which cases will progress and which will regress, and clinicians are therefore obliged to treat all. This will result in the destruction of many lesions of uncertain malignant potential. The secondary prevention of cervical cancer, although therapeutically efficacious, is inefficient. A lack of understanding of the natural history of intraepithelial neoplasia has frustrated attempts to develop rational referral criteria, and it is only now that the appropriate trials are being undertaken. The development of outpatient investigative and therapeutic procedures has resulted in many more women being referred for investigation and treatment, with predictable pressure on other services offered by gynaecologists, but no demonstrable saving of life. Similar uncertainties surround a screening programme for colorectal cancer. The principal concerns are not about the efficacy of polypectomy in interrupting the polyp cancer sequence, although uncertainties about the frequency with which cancer arises de novo do require that the effectiveness of this intervention is formally tested. Our major concerns are with compliance, and the management of the individual who tests positive--that is, who is found to have a distal polyp. Technological advances and operator enthusiasm may, as has happened with the cervical screening programme, lead to a relaxation in the indications for further investigation and treatment. Such a development would affect resources substantially if a population screening programme were in place. Nevertheless, there are grounds for believing that a screening programme for colorectal cancer, using sigmoidoscopy, might be successful in certain age groups if compliance was satisfactory. The scale of benefits may be comparable with those achieved by the breast screening programme. Our limited cost analysis, which relates to only to specific items of clinical activity, suggest that the mean cost for each case of cancer prevented will be about 8000 pounds sterling. These conclusions suggest that screening by flexible sigmoidoscopy merits serious consideration. It is also imperative, however, that consideration should be given to resolving some of the uncertainties about the clinical management and surveillance of those found to have distal polyps.

The normal preterm foetal heart rate pattern

A longitudinal study was carried out on 38 women with low risk pregnancies. These women had cardiotocography at 27-28 wk initially, at fortnightly intervals thereafter until 36 wk and at weekly intervals thereafter until delivery. All cardiotocographs were analyzed by one investigator who was not aware of the individual clinical situation. Of the 232 cardiotocographs, 12 (0.5%) of poor quality were excluded from analyses. The mean base-line heart rate decreased from 142.5 (SD 6.03) beats per min at 27-30 wk to 138.2 (SD 7.4) at term. Analysis of variance for repeated measures showed that the decrease in foetal heart rate with gestation was statistically significant (P < 0.001). The number of accelerations increased with gestation (P = 0.002). There were no significant changes in variability and decelerations with increasing gestation.

Towards improved perinatal care--perinatal audit

Perinatal audit is a measure of quality of care given in pregnancy and it gives an idea as to how the resources need to be allocated for better outcome. The perinatal mortality data in the National University Hospital over a 7-year period (1986-1992) were compiled and compared with that of the year 1982. The perinatal mortality rate (PNMR) of 14.6/1000 in 1982 declined to 8.9/1000 for the period 1986 to 1992 and the reduction was noticeable in all ethnic groups, particularly in the Malays. When lethal congenital malformations (LCMs) were excluded, the PNMR decreased to 5.7/1000. Such reduction is due to easy availability and acceptance of antenatal care, improvement in antenatal and intrapartum fetal surveillance and advances in neonatal care. Neonatal audit was extended beyond the first 7 days of birth which showed that the majority (65%) of deaths occurred in the first week and 15% occurred after the first month. The fear that intensive neonatal care serves to postpone death is not entirely substantiated. There was nearly a ten-fold rise in PNMR between the non-low birthweight and low birthweight groups. The important causes of perinatal mortality during the review period were LCMs (35.7%), complications of prematurity (17.9%) and asphyxia (15.3%). No cause was identifiable in 28.5%. Detailed analysis revealed that the standard of care could have been improved in a third of the cases (83/235) which could have led to further reduction of perinatal mortality rate.

Exon organization and sequence of the genes encoding alpha-lactalbumin and beta-lactoglobulin from the tammar wallaby (Macropodidae, Marsupialia)

Clones encompassing the genes encoding alpha-lactalbumin and beta-lactoglobulin were isolated from a tammar wallaby genomic library, the exons localized using end-labeled oligonucleotides and the DNA sequences determined. The tammar beta-lactoglobulin gene has the same 7 exon-6 intron structure as the sheep homologue. Potential binding sites for mammary gland-specific transcription factors were identified, on the basis of similarity to sites in the sheep gene, in the promoter region of the tammar beta-lactoglobulin gene. The tammar gene encoding alpha-lactalbumin appears to contain four introns rather than three as are present in the eutherian homologues, or the evolutionarily related lysozyme gene. The additional intron appears to occur within the 5' noncoding region of the tammar gene.

Interference by nonsteroidal anti-inflammatory drugs in EMIT and TDx assays for drugs of abuse

Fourteen nonsteroidal anti-inflammatory drugs were evaluated for interference in EMIT and TDx assays for drugs of abuse. Only tolmetin demonstrated significant interferences in the EMIT assay. Urine samples that contained high concentrations of tolmetin (1800 mg/L) had characteristic high molar absorptivity at the wavelength used in EMIT assays (340 nm). Consequently, EMIT analysis of samples resulted in instrument error alarms on a Hitachi 704 instrument and depressed milliabsorbance values (delta A) relative to calibrators. Similar results were obtained with urine samples collected from an arthritic patient after the administration of 200 and 400 mg of tolmetin. When tolmetin samples were mixed with drugs of abuse, depressed delta A values were noted in all assays. Samples containing opiates and cannabinoids tested negative, and instrument error alarms were produced with samples that contained amphetamines. A gas chromatographic-mass spectrometric (GC-MS) assay for benzoylecgonine in the presence of tolmetin was successful, and no interferences were noted. Similar interferences by tolmetin were not observed in TDx assays, probably because of the different wavelength (525 nm) used in this assay. However, a potential for false-positive results in the TDx benzodiazepine assay was noted for urine samples containing high concentrations of fenoprofen, flurbiprofen, indomethacin, ketoprofen, and tolmetin. Generally, it was concluded that the presence of tolmetin in urine samples could lead to the production of unacceptable results by the EMIT assay for drugs of abuse. However, TDx and GC-MS assays were useful alternatives for the analysis of urine samples suspected of containing tolmetin.

Growth pattern of the Indian fetus

OBJECTIVES

To determine the pattern of intrauterine growth and the gestation at birth of Indian fetuses.

METHOD

One hundred twenty consecutive women who had reliable menstrual histories, low-risk pregnancies and who were booked for delivery at the Christian Medical College Hospital, Vellore, before 20 weeks' gestation were recruited to the study. Ultrasound fetal biometry was carried out at 4-weekly intervals from 20 weeks and at weekly intervals after 36 weeks until delivery.

RESULTS

Growth patterns of fetal biparietal diameter and femur length were comparable to those reported in Western populations. However there was a lag in growth of abdominal circumference (AC) after 28 weeks in comparison with that reported in Western populations. The median gestation at delivery following spontaneous labor was 39 weeks. No association was observed between rate of growth of AC and gestation at birth.

CONCLUSION

Slowing of growth of the fetal AC after 28 weeks and a shorter length of gestation result in the birth of smaller babies in this ethnic group. The implications of these findings are discussed.

The pruritogenic and inflammatory effects of prostanoids in the conjunctiva

The therapeutic utility of cyclooxygenase (CO) inhibitors, such as ketorolac, in reducing the inflammatory events associated with allergic conjunctivitis is not unexpected since prostanoids (PG) elicit conjunctival redness (PGD2, PGE2, PGF2 alpha), edema (PGD2, TxA2), eosinophil infiltration (PGD2, PGJ2) and mucous cell discharge (PGD2, PGJ2, TxA2). Recently, topically administered ketorolac has also been reported to alleviate the itching associated with allergic conjunctivitis. This was viewed as intriguing since CO inhibitors are not regarded as useful for treating itching dermatoses and PGs do not elicit itching when applied to the skin. In order to investigate the antipruritic activity of ketorolac, we developed a model for reproducibly measuring ocular surface itch responses. The model involves itch-scratch responses to pruritogens applied locally to the ocular surface. Painful and foreign body stimuli do not produce an itch-scratch response. Unlike reported skin studies, PGE2 was a potent itch-producing substances in the conjunctiva. PGD2 was weakly pruritogenic but PGF2 alpha and the TxA2-mimetic U-46619 were inactive. The PG precursor arachidonic acid was also a potent pruritogen and its effects were inhibited by ketorolac pretreatment. Ketorolac also dose-dependently inhibited the itching associated with experimental allergic conjunctivitis. It appears that PGs are potent itch-producing substances in the conjunctiva and the anti-itch efficacy of ketorolac in allergic conjunctivitis appears to involve inhibition of conjunctival PG biosynthesis from arachidonic acid.

Fournier's gangrene: CT findings

Fournier's gangrene is an uncommon gas-forming infection of the scrotum which if not recognized early and treated appropriately may be fatal. In three patients recently seen at our institution, computed tomography (CT) was instrumental in establishing the correct diagnosis and determining the extent of the infectious process prior to surgery. The imaging findings at CT and its differential diagnosis are illustrated. A brief review of the current theories of pathogenesis of this interesting entity is presented.

Molecular cloning of a novel mRNA (neuronatin) that is highly expressed in neonatal mammalian brain

As differential gene expression governs the progression of development into senescence, we attempted to define the genes that are selectively expressed during postnatal brain development. A cDNA fragment selectively expressed in neonatal rat brain was identified by differential display and used to screen a cDNA library prepared from the same mRNA sample. The full length cDNA, neuronatin, was 1195bp long and coded for a novel protein of 81 amino acids. The cDNA detected an mRNA species of similar size that was highly expressed in rat neonatal and human fetal brain. The deduced protein exhibited a hydrophobic N-terminal and hydrophilic C-terminal, suggesting that it is membrane bound and might function in signal transduction. The selective expression of this novel mRNA in late fetal and early postnatal brain development, and loss of expression in adulthood and senescence, suggests that downregulation of neuronatin may be involved in terminal brain differentiation.

The identification of nuclear and mitochondrial genes by sequencing randomly chosen clones from a marsupial mammary gland cDNA library

To increase the number of genes that can be mapped to the genome of the tammar wallaby (Macropus eugenii), we sequenced 100 randomly chosen clones from a mammary gland cDNA library. Provisional identifications were made of seven nuclear genes and one mitochondrial gene encoding two caseins, beta-galactosidase, acetyl-coenzyme A synthetase, lipoprotein lipase, inorganic pyrophosphatase, an ATP-dependent RNA helicase, and cytochrome c oxidase I. Highly conserved genes, such as that encoding acetyl-coenzyme A synthetase, were easily identified even from cross-kingdom matches. Genes which are highly divergent, however, such as those encoding the mature casein peptides, could not be aligned with homologues in the databases. Even in an organ where there is high mRNA species redundancy, the sequence characterization of expressed sequence tags provides a rapid means of gene identification for mapping purposes.

Double staining in situ study of mRNAs encoding milk proteins in the mammary gland of the tammar wallaby (Macropus eugenii)

Oligonucleotides, differentially tagged with fluorochromes, were used to determine whether the distribution of mRNAs encoding the major milk proteins is heterogeneous within the mammary gland of the tammar wallaby (Macropus eugenii). This method also allowed direct visualization of two species of mRNA within the same cell. Sections of early and late lactating glands of tammar wallabies were hybridized with oligonucleotides labelled with fluorescein isothiocyanate or rhodamine isothiocyanate either alone or in combination. The results support the hypothesis that milk secretion is an all-or-none process with all epithelial cells in a given alveolus producing the same suite of milk proteins. In tammar wallabies, a gene encoding a protein specific to the latter phase of lactation appears to be expressed in those cells already secreting the other major milk proteins.

Alteration of semen characteristics and regulatory factors in human semen with bacterial infection

Semen samples (n = 40) obtained from males attending an infertility clinic were subjected to bacteriological culture and categorized as bacteriologically negative (group I) and bacteriologically positive (group II) depending on the culture positivity. Semen samples from both groups were simultaneously analyzed for routine parameters such as volume, count, motility, viability, morphology, pH, and hypoosmotic swelling. Seminal plasma was assayed for levels of prolactin (PRL), prolactin-suppressing factor (PSF), prostatic inhibin peptide (PIP) and zinc (Zn). Patients in group II (n = 25) showed statistically significant alteration (p < .01) in semen parameters such as motility, percent normal morphological forms, and percent normal HOS test as compared to group I (n = 15). There was a negligible change in the sperm concentration between the two groups. The semen volume, viability, and pH did not show any variation. Among the regulatory factors assayed, there was a significant change in the Zn, PSF (p < .05), and PIP (p = .01), while no such alterations were seen for PRL. The results suggest that bacterial infection affects fertility either by affecting the seminal characteristics directly or by acting on the regulatory systems.

Occurrence and de novo biosynthesis of follicle stimulating hormone (FSH) in benign and malignant conditions of human breast

We report the occurrence as well as biosynthesis of a pituitary hormone, follicle stimulating hormone (FSH) in human breast. Using immunoperoxidase localization technique, both FSH and beta-FSH were localized in cytoplasm of epithelial cells but not in stromal cells. Immunostaining was more intense in benign and malignant specimens as compared to normal. In vitro radiolabelled precursor experiments with breast tissue explants indicate de novo synthesis of FSH. Human milk had higher concentrations of FSH as compared to serum. In gonads, FSH is involved in the cellular growth, differentiation and function. The presence of higher levels of FSH in benign mammary tumors and breast cancer when compared to normal breast supports the suggestion that FSH might have a role in the process of breast malignant transformation.

Neuronal beta-amyloid precursor protein gene expression: regulation by aurintricarboxylic acid

beta-Amyloid precursor protein (beta-APP) and its derivative, amyloid beta-protein (beta-A4), may cause death of differentiated neurons and aurintricarboxylic acid (ATA), a metabolic inhibitor, improves neuronal survival. Therefore, we studied the effect of ATA on neuronal beta-APP gene expression. ATA decreased beta-APP mRNA levels by increasing its degradation, without changing the rate of transcription. ATA decreased both steady state and interleukin-1 (IL1)-induced increase in beta-APP mRNA levels. These effects of ATA were associated with rounding of cells suggestive of decreased cell adhesion or neurite retraction that was completely reversible when ATA was removed. However, beta-APP mRNA levels continued to remain suppressed in neurons that were actively regrowing neurites following discontinuation of ATA. In studies carried out upto 24 h, ATA did not damage cells as determined by Trypan blue exclusion, lactate dehydrogenase (LDH)-release and transmission electron microscopy. The findings suggest that constitutive or steady state levels of beta-APP mRNA may not be essential for the survival and growth of neurons and that ATA suppresses beta-APP expression without causing cell damage. These observations may be a basis for studying whether ATA or a related compound could beneficially regulate beta-APP levels in vivo.

Gonadal function in prepubertal boys following treatment for Hodgkin's disease

PURPOSE

Gonadal functions were evaluated in 26 male patients with Hodgkin's disease (HD), who were in continuous unmaintained remission following combination chemotherapy consisting of COPP/MOPP.

MATERIALS AND METHODS

These patients had received chemotherapy during the prepubertal phase. The median duration after termination of chemotherapy was 72 months.

RESULTS

Semen analysis of 18 patients showed azoospermia. Hormonal analysis showed elevated mean levels follicle-stimulating hormone (FSH) and inhibin as compared to age-matched controls, whereas luteinizing hormone levels were only marginally elevated.

CONCLUSIONS

These results suggest that COPP/MOPP causes severe damage to germinal epithelium even when given during prepubertal age. Sertoli cells, which are responsible for secretion of inhibin, are resistant to these cytotoxic agents. Our data emphasize the lack of gross dysfunction of Leydig cells. It is possible that an alternative chemotherapy protocol (ABVD) may be used in young patients to minimize the gonadal damage.

Free thyroxine as a supplement to thyrotropin in cord screening for hypothyroidism

The low specificity of cord serum T4 levels for detecting hypothyroidism, the need to reduce recall rates and the availability of a reliable and quick assay system led to this study designed to determine the advantages of using cord serum free thyroxine levels over total thyroxine levels as a supplement to cord thyroid stimulating hormone (TSH) determination. Sixty-eight out of 75 newborns with a cord TSH > 23 mU/l had both free thyroxine (fT4) and T4 levels measured in the cord serum. All were recalled within the first month of life for reevaluation of their thyroid status. In the majority of cases (46), the fT4 and T4 values corresponded. Hypothyroidism was diagnosed in eight cases; both fT4 and T4 were below the mean in five cases and above the mean in one case; only T4 was below the mean in one and in the remaining one, only fT4 was below the mean. Recall rates were 0.9% with TSH alone and 0.7% when either a fT4 or T4 level that was less than 1 sd above the mean was used as a supplement to TSH. In this cohort, using the fT4 levels instead of the T4 levels brought no change to the specificity or the sensitivity of the screening. The diagnostic sensitivity would have dropped from 100% to 75% if either T4 or fT4 values below the mean were used as a cut-off point for recall.

A novel member of the lipocalin superfamily: tammar wallaby late-lactation protein

The finding that tammar wallaby late-lactation protein is linked to beta-lactoglobulin prompted a search of current GenPeptide and NBRF-PIR protein databases for sequence similarities to late-lactation protein. Similarities were found to von Ebner's gland protein and other members of the lipocalin superfamily of proteins. A conservative replacement of Trp with Tyr suggests that late-lactation protein may represent an unusual member of this protein superfamily.

Neuronal death, cytoplasmic calcium and internucleosomal DNA fragmentation: evidence for DNA fragments being released from cells

Neuronal death, secondary to endogenous agents such as glutamate, may involve changes in cytoplasmic calcium. Besides its well recognized role as a second messenger mediating cellular response, calcium is necessary for the activation of endonuclease(s), resulting in DNA fragmentation and cell death. Therefore, we investigated the relationship between changes in cytoplasmic calcium, DNA fragmentation and neuronal death, using PC12 and NCB-20 cell lines. The calcium ionophore, A23187, caused a dose-dependent increase in cytoplasmic calcium, loss of cell viability, increased lactate dehydrogenase (LDH)-release, and DNA fragmentation. DNA fragments, typical of internucleosomal digestion of genomic DNA, characteristic of endonuclease(s) activation, were consistently detected in the incubating medium. Release of DNA fragments into the medium was seen with A23187 in concentrations as low as 10 nM, and within an hour of treatment. Furthermore, calcium added to preparations of PC12 nuclei also produced DNA fragmentation, although, less pronounced than when intact cells were treated with A23187. The findings indicate that A23187-induced neuronal death involves the activation of endonuclease(s). The role of cytoplasmic calcium in this process is supported by evidence that A23187 selectively mobilizes cytoplasmic calcium, and that calcium can directly activate endonuclease(s) in nuclear preparations.

On the significance of different aequorin loading techniques on intracellular aequorin discharge, baseline calcium, platelet aggregation and aequorin-indicated Ca(2+)-transients

The study compares the decay of intracellular luminescence activity (Lmax), the levels of basal [Ca2+]i in resting platelets, and agonist-induced peak [Ca2+]i-signals in platelets loaded with aequorin using the EGTA-, DMSO- and hypoosmotic shock treatment (HOST)-techniques. The highest load of intracellular aequorin with almost unchanged luminescence activity during 4 h was achieved with HOST. Lmax decreased linearly in EGTA- and HOST-platelets, but the decay rate and the levels of basal [Ca2+]i were significantly lower in HOST-platelets. Platelet aggregation and aequorin-indicated [Ca2+]i-rise induced by thrombin and collagen were similar in EGTA- and HOST-platelets. In HOST-platelets, ADP-induced platelet aggregation was always accompanied by aequorin-signals, while at a similar time point, aequorin-signals were absent in 3 of 5 cases in EGTA-platelets. The initial aequorin loading was highest in DMSO-platelets, but Lmax described an exponential decay, which was most pronounced when DMSO-platelets were maintained in Ca(2+)-free buffer (R2 = 0.86). Agonist-induced platelet aggregation was significantly reduced in DMSO-platelets: thrombin-stimulation was accompanied by a significantly lower and delayed [Ca2+]i-rise and no aequorin-signal was obtained in response to ADP in 3 of 5 cases. The study shows that in addition of being a rapid loading-technique, the criteria of high intracellular aequorin load with low luminescence consumption, low basal [Ca2+]i and completely preserved platelet functions are most convincingly met by the HOST-method.

Diagnosis of acute diffuse pulmonary infiltrates in immunosuppressed patients by open biopsy of the lung

Herein is a review of the results of open biopsies of the lung performed upon immunosuppressed patients between the years 1982 and 1988. The goal was to assess the safety and value of the procedure on a group of patients who are many times in extremis because of multiorgan failure. Obtaining the correct diagnosis and establishing treatment poses a challenge. The study includes 74 patients. Fifty-four had malignant tumors; 20 had various diseases associated with immunosuppression. The biopsy was obtained from the left side in 65 instances. An adequate thoracotomy was done to permit exploration of the thoracic cavity and obtain a representative sample of tissue. The mortality rate related to the operation was 1.4 percent and the complication rate was 11.0 percent. Forty-six percent of the infiltrates were the result of infection. In 42 percent, a change in treatment was made. Thirty-two percent survived and were discharged from the hospital. Patients with adverse drug reaction, with nonspecific pneumonitis and with bacterial infection had a favorable prognosis and benefited most from open biopsy of the lung.