Testis-specific expression of a metallothionein I-driven transgene correlates with undermethylation of the locus in testicular DNA

Mice carrying a chimeric transgene of the human testis-specific lactate dehydrogenase cDNA driven by mouse metallothionein I promoter have been reported to express the transgene in a testis-specific manner in six founder lines. To study the mechanism by which this testis-specific expression is mediated, we have examined genomic placement, expression pattern, and methylation status of the transgene. Our results indicate that transgene expression is repressed in all somatic tissues examined even when heavy metals are administered. Nuclear run-on assays indicate that failure of expression in the liver (in which the metallothionein I promoter is highly active) occurs at the transcriptional level. In contrast, the transgene mRNA is transcribed in male germ cells and is developmentally regulated during spermatogenesis. Examination of the transgene methylation status reveals that expression is inversely correlated with hypermethylation of the locus; all CpG dinucleotides examined in the promoter region were found to be fully methylated in kidney and liver but were undermethylated in testis. Since methylation of the murine metallothionein I promoter is sufficient to inhibit its activity, it is likely that suppression of the transgene in somatic tissues is mediated by methylation.

Tracing the incorporation of the sperm tail in the mouse zygote and early embryo using an anti-testicular alpha-tubulin antibody

The mechanism of sperm tail incorporation and the fate of the tail during mouse fertilization and early embryogenesis were examined. Time-lapse video microscopy and anti-tubulin immunofluorescence show that the incorporation of the sperm tail, but not the sperm head, is sensitive to cytochalasin B (a microfilament inhibitor). Colcemid, a microtubule inhibitor, does not affect tail incorporation. High-resolution, low-voltage scanning electron microscopy demonstrates that the plasma membrane covering the sperm tail does not appear to fuse with the oocyte membrane during in vitro fertilization in the presence of cytochalasin. In control and colcemid-treated oocytes, the plasma membrane along the sperm tail, which is oriented tangential to the egg surfaces, appears to fuse with the oocyte membrane at multiple sites. An antibody to testicular alpha-tubulin detects sperm-derived, but not egg, microtubules and this has permitted us to trace the behavior and disappearance of the sperm tail during embryogenesis. Conventional and confocal microscopy show that following sperm incorporation, the tail often splays into multiple fibers. At the two-cell stage, the axoneme may be localized in either blastomere or it may be found to run through the midbody between both blastomeres. The tail appears to shorten by the 8-cell stage and is undetectable after the 16-32 cell stage. In morulae, tail fragments have been found in outer cells but not in inner ones, and fragments have not be found in blastocysts. These data suggest that microtubules of sperm and oocytes contain different isotypes of alpha-tubulin, nongenomic sperm-derived components survive at least to the morula stage of mouse development, and egg microfilaments are involved in the incorporation of the sperm tail but not the sperm head, which demonstrates that motility during sperm incorporation is different in mammals when compared to lower vertebrates and invertebrates.

Correlates of military tank simulator sickness

A military tank driving simulator is currently widely used as a training aid for tank drivers. The purpose of this study was to investigate the relationship between possible correlates of simulator sickness and the occurrence of sickness and performance test results among simulator drivers. The average number of motion sickness-like symptoms reported after driving the simulator among subjects with a history of susceptibility to motion sickness was 3.4, significantly higher than the average of 1.6 reported among subjects who did not report previous susceptibility to motion sickness (p < 0.05). Subjects driving the simulator while screen image quality was disturbed had a longer reaction time (42.0 s) than when driving the simulator without screen interferences (18.4 s, p = 0.001). Subjects driving the simulator for a short period had the same number of symptoms as did those driving for a longer period, but had better digit symbol test results. There was no statistically significant association between the development of sickness and tank driving experience. Suggested countermeasures are expected to prevent simulator sickness among some of the simulator trainees and to make simulator training more effective.

Immunoelectron microscopic localization of testicular and somatic cytochromes c in the seminiferous epithelium of the rat

Somatic and testis-specific cytochromes c were localized ultrastructurally in the seminiferous epithelium by immunocytochemistry using monospecific antibodies. Cytochrome cS was lost from the mitochondria as spermatogenesis advanced, while there was a relative increase in cytochrome cT during the zygotene-to-pachytene transition; this was in agreement with other studies that have suggested activation of the cytochrome cT gene during prophase of the first meiotic division. Cytochrome cT was highly concentrated in mitochondria that were being degraded within cytoplasmic lobes of spermatids and in residual bodies that were phagocytized by Sertoli cells. The two isoforms were found to coexist within the same mitochondrion during the transitional period from cytochrome cS to cytochrome cT predominance. In addition, both cytochromes c were present in the chromatoid bodies of spermatocytes and round spermatids; this suggests that the chromatoid body may be involved in the storage of these isozymes and possibly in their differential expression within germ cell mitochondria. Apocytochrome c was concentrated in mitochondria and chromatoid bodies of the germ cells and also scattered in the cytoplasm. The presence of the holoprotein and apoprotein immunoprobes within the chromatoid bodies of spermatocytes and spermatids was an interesting observation that raises questions regarding the precise location of the synthesis of cytochromes c in spermatogenic cells.

Health education for Ethiopian immigrants in Israel, 1991-92

A health education program was developed to address the immediate needs of 20,000 Ethiopian immigrants to Israel in 1991. This modular program included: the use of health services, nutrition, prescription medication use, prevention of home accidents, first-aid and personal hygiene. Using an anthropological orientation, the program attempted to bridge the cultural gap regarding the health promotion skills of this population that had moved from a developing country to a new, Western society in Israel. The program was implemented throughout the country by specially trained veteran Ethiopian immigrants, some of whom were also health professionals, using newly developed visual tools. Over 4,300 adults participated in the program between August 1991 and August 1992. The program was positively accepted by the participants, who expressed their satisfaction with the content and materials. The tools developed were deemed successful in their cultural sensitivity, flexibility to local needs, and clarity. We suggest that various modules of the program continue to be implemented in order to address the rapidly changing health behavior needs of the Ethiopian immigrants in Israel, and that new modules be developed.

Genomic structure and promoter activity of the human testis lactate dehydrogenase gene

The structure of the gene encoding the human testis-specific isozyme of lactate dehydrogenase (LDH) has been characterized and a regulatory region identified by promoter activity. The single-copy ldh-c gene has two alternative 5' noncoding exons and seven coding exons comprising an approximately 40-kb locus. The gene does not contain the canonical TATA or CAAT promoter sequences, and ribonuclease protection experiments suggest multiple transcription start sites. In the present study an immortalized murine germ cell line was used to detect promoter activity driven by 5' sequence of human ldh-c with lacZ as the reporter gene. Reporter gene activity was nondetectable when promoter constructs were transfected into nongerminal cells.

A randomized controlled trial of home exercise on the rheumatoid hand

OBJECTIVE

To study differing home hand exercise interventions to determine effects on grip strength, and secondarily any immediate or short term effects on range of motion, pain, deformities, hand disease activity, and dexterity.

METHODS

Randomized controlled trial of 12 weeks of home hand exercise performed for 10-20 min twice daily. Study exercise interventions were range of motion exercises, balanced resistive exercises, and range of motion plus balanced resistive exercises.

RESULTS

Aside from transient, mild to moderate discomfort, exercises were well tolerated. Range of motion exercises were associated with improved right hand joint count. Range of motion plus balanced resistive exercises were associated with increased left hand dexterity. Home hand exercise (exercise groups combined) significantly increased left grip strength.

CONCLUSIONS

Temporary use of home hand exercise has acceptable side effects and is an effective means of increasing grip strength.

Differences in regulation of testis specifc lactate dehydrogenase in rat and mouse occur at multiple levels

The testis specific form of lactate dehydrogenase (LDH-C4) is encoded by a single locus, Ldh-c, and is tightly regulated in a tissue specific manner. Here we show differences in expression of Ldh-c between rat and mouse, and describe the levels at which regulation of this gene differs in the two species. Our results demonstrate that the Ldh-c message level is nearly nine fold greater in mouse testis and remains high post-meiotically. In contrast, rat Ldh-c mRNA is highest in primary spermatocytes and reduced in spermatids. The results of nuclear run-on assays indicate that the transcription rate of Ldh-c is only moderately higher in mouse than rat, and cannot account for a significant portion of the observed differences. Similar decay rates for both rat and mouse Ldh-c mRNA in actinomycin-D clearance assays indicate comparable cytoplasmic stabilities for the two messages. From these results we infer that nuclear prostranscriptional events contribute to the differences in Ldh-c message levels.

Removal of nasal foreign bodies in children

Among the foreign bodies most often found in children's nostrils are hair, beads, toy parts, paper wads, and food. Sometimes extraction of nasal foreign bodies can be difficult, especially if they are spherical. The classical presentation is a unilateral, persistent, foul-smelling, purulent, or bloody nasal discharge. Ulceration, dislodgement of the foreign body into the nasopharynx, and aspiration of the foreign body can complicate the problem.

Spinal subdural hematoma: a rare cause of recurrent postoperative radiculopathy

Spinal subdural hematoma is a rare condition with numerous etiologies. It is even more rare in the postoperative period and must be differentiated from the more common causes of postoperative pain and radiculopathy. We report a 36-year-old man presenting 6 weeks after surgery with incapacitating pain who was found to have a subdural but extraarachnoid fluid collection. We describe clinical presentation, radiological findings, etiology, and treatment. We conclude that, although rare, the spinal subdural hematoma should be considered in patients with postoperative pain. Prompt recognition and surgical evacuation are important for optimal recovery.

An inexpensive microdrive for chronic single-unit recording

A microdrive and microelectrode costing about $2.67 is described. The assembly is lightweight, compact, and versatile and is ideal for chronic single-unit recording from behaving rats. It is easy to assemble and operate and has been used successfully by undergraduates in the teaching and research laboratory.

Mesothelioma mortality among former asbestos-cement workers in Israel, 1953-90

Asbestos workers have long been recognized as a high risk group for the development of mesothelioma and other cancers. In this study we collated from a variety of sources 26 mesothelioma deaths that occurred between 1978 and 1990 among a cohort of some 4,441 former workers from an asbestos-cement plant in northern Israel. Since the expected number of deaths for this number of Israeli males in this age-group over this period is 0.12 cases, the risk of this disease was more than 223 times the national rate, age and sex adjusted [standardized mortality ratio (SMR) = 22,351, P < 0.001]. The mean years of exposure of persons who died from mesothelioma was 16.2 (SE 2.5). The mean latency period for mesothelioma cases from onset of exposure to death was 25.6 years (SE 1.3). Additional follow-up systems are needed to ensure complete reporting of asbestos-related diseases, including epidemiologic follow-up of asbestos-exposed workers after cessation of their work, with regular analysis of death and cancer registry data for high risk groups. Asbestos-related cancer is an important element in cancer epidemiology that requires further development in Israel. Studies of former workers, their families and of persons who worked or attended school adjacent to the asbestos-cement factory, as well as follow-up of other former worker groups exposed to asbestos are recommended.

Motion sickness-like syndrome among tank simulator drivers

A military tank driving simulator has recently been introduced as a training aid for tank drivers in the Israel Defense Forces. Reports of nausea and vomiting among the first users of the simulator launched our investigation of the possible existence of a motion sickness-like syndrome among simulator drivers. Although the 59 subjects drove the simulator without any report of vomiting, other motion sickness-like symptoms were frequently reported. A comparison of symptoms reported after simulator and real tank driving show that dizziness, nausea, disorientation and hypersalivation were more frequently reported by simulator drivers and were of greater intensity. However, sweating and drowsiness were more prevalent among real tank drivers. The objective effect of driving the simulator was evaluated by instability and performance tests that were conducted before, during and after driving the simulator. A greater decrement in test results was observed among subjects reporting higher frequency of motion sickness-like symptoms.

Combined ovarian vein catheterization with ovarian stimulation in the diagnosis of androgen overproduction

A 28-year-old woman was evaluated for late onset secondary amenorrhea, progressive hirsutism and an elevated serum testosterone concentration. Her serum cortisol, androstenedione, dehydroepiandrosterone sulfate and 17-hydroxyprogesterone levels were normal. Bilateral ovarian and adrenal vein catheterization demonstrated mild elevated testosterone and androstenedione levels in the right ovarian vein. Fifteen minutes after administering the intravenous injection of 5,000 IU human chorionic gonadotropin, there was a six and a half to sevenfold increase in the level of these two hormones in the right ovarian vein with no significant change in hormone levels from other sources. Based on the ovarian peripheral vein gradients obtained during venography following ovarian stimulation, the diagnosis of right ovarian hyperthecosis was made. This diagnosis could not have been reached without the combination of selective ovarian vein catheterization and ovarian stimulation. We recommend that this combined test, which may provide additional information on the source of the androgens in women with hyperandrogens, be performed in selected cases, when a virilizing tumor is suspected.

Design and immunological properties of topographic immunogenic determinants of a protein antigen (LDH-C4) as vaccines

Antibodies elicited by immunization with short peptides containing antigenic determinants have been shown, in general, to bind with greatly reduced affinity to the corresponding region in the native proteins. Thus, contiguous linear peptides have not proven to be effective immunogens in generating high affinity neutralizing or protective antibodies and consequently appear to be poor prospects for vaccines. The molecular basis for such reduced reactivity is clear from the crystal structure determination of antibody Fabs bound to protein antigens, which showed the complementarity between interfaces to be lock-and-key-like and extending over a large area (750 A2) involving discontinuous segments of the polypeptide chain. Thus, small perturbations in the secondary and tertiary structure of the antigen have profound effects on the fit of the antigen and its corresponding antibody. Because short peptides are unlikely to assume any particular conformation in solution, the fit is likely to be poor. New strategies are therefore required to produce conformationally stable peptides that mimic the critical structural features of the protein antigenic site. Here we show that a putative topographic determinant of the testis-specific isozyme of lactate dehydrogenase C4 (LDH-C4), designed and synthesized to adopt a well defined alpha-helical secondary and tertiary structure (four-helix bundle motif) in aqueous solutions, is highly immunogenic in both rabbits and mice, inducing IgG antibodies that bind to native LDH-C4. This engineered conformational 40-residue peptide is considerably more effective in inducing antibodies, as compared with the corresponding linear peptide. The antibody response is obtained without coupling the peptide to a carrier protein, suggesting that the peptide contains a T-cell antigenic determinant. The strategy described here to produce a conformationally stable peptide that mimics the native structure may have general applications in vaccine design.

Associations between sexual experiences and fantasies in a nonpatient population: a preliminary study

We have been interested in devising some methodology short of psychoanalytic therapy to study the relationship of conscious fantasy to personality trends and behavior. Presented here is a pilot study, utilizing the questionnaire technique, the sample consisting of 193 students enrolled at one prestigious urban university, that reports on the prevalence and content of conscious sexual fantasies in a normal (nonpatient) population and their relationship to sexual behaviors. Factor analysis suggested four experience and four fantasy clusters. Those individuals who score high on one experience factor are apt to score high on all other experience factors as well. The same is true of the fantasy factors. Our findings indicate that low sexual activity and low levels of sexual fantasy go together, whereas more sexual experience is connected to a greater range of sexual fantasy. Consequently, erotic fantasies cannot be viewed as compensation for lack of sexual outlet. Instead, there is a positive correlation between the two domains of sexual fantasies and sexual behaviors. Our overall results lead us to conclude that by and large, people are sexual generalists not specialists.

Hypertrophic obstructive cardiomyopathy presenting with profound hypotension. Role of two-dimensional and Doppler echocardiography in diagnosis and management

Five patients, all women, age ranges 59 to 84 years, with underlying hypertrophic obstructive cardiomyopathy (HOCM) presented with profound hypotension. Initial clinical and hemodynamic evaluation suggested cardiogenic shock in two cases, acute myocardial ischemia in two cases, and hypovolemia in one case. The two patients thought to be in cardiogenic shock were given inotropes without improvement. One patient in whom myocardial ischemia was suspected received nitroglycerin, followed by a marked fall in blood pressure. All five patients remained hypotensive until two-dimensional and Doppler echocardiography were performed, identifying HOCM as the cause of the hypotension, thereby allowing for corrective therapeutic measures.

Protein turnover and resting energy expenditure in patients with undernutrition and chronic lung disease

Whole-body protein metabolism was studied in 11 undernourished cystic fibrosis (CF) patient (7 female), 12 normally nourished CF patients (3 female), 7 anorexia nervosa (AN) patients (all female), and 15 normal control subjects (9 female). Protein turnover was studied by the single dose [15N]glycine method and the cumulative excretion of labeled urinary urea and ammonia. Energy metabolism was studied by open-circuit indirect calorimetry. Contrary to previous reports, no differences were found between the protein turnover of CF groups and the normal control group. However, patients with AN had a negative net protein deposition. Resting energy expenditure was significantly reduced in AN patients and increased in CF patients. The gender of CF patients did not affect protein and energy metabolism but fat mass was higher and fat-free mass was lower in CF females.

Transperineal ultrasound examination in the evaluation of prostatic size

Eighty patients with benign prostatic hyperplasia underwent transperineal ultrasonographic evaluation of prostatic size and calculation of prostatic volume. In 10 patients transabdominal prostatic ultrasonography was also performed and the findings compared with those of transperineal examination. The estimated prostatic volume measured by transperineal ultrasonography was compared to the actual weight of the surgically removed gland. The correlation coefficient was 0.89 (P less than 0.0001). The transperineal and transabdominal ultrasonographic estimated volumes were also compared. The correlation coefficient was 0.92 (P less than 0.0001). No pain or discomfort were reported by the patients. Transperineal ultrasonography appears to be an accurate, fast and easy method to evaluate prostatic volume.

Effect of refeeding on the energy metabolism of adolescent girls who have anorexia nervosa

The effect of refeeding on resting energy expenditure (REE) and substrate utilization was studied in 18 hospitalized adolescent girls (aged 12.9-19.1 years) suffering from anorexia nervosa. Changes in body composition were monitored weekly and included weight, fat body mass (FBM), lean body mass (LBM) and total body potassium (TBK). REE was studied weekly by open-circuit calorimetry. Weight gain was noted in all patients (38.2 +/- 5.6 to 44.5 +/- 5.3 kg), involving increased FBM and LBM. REE increased per kg of weight (91.6 +/- 15.1 to 101.7 +/- 18.0 kJ kg-1 d-1) and LBM over the first weeks of refeeding (P less than 0.025) and then stabilized. Substrate utilization showed an increase in carbohydrate and protein utilization (P less than 0.001) during the first few weeks of refeeding. We also studied the thermic effect of food (TEF) in 14 of the 18 subjects. Upon admission the subjects had a reduced TEF (36.4 +/- 24.3 kJ 2 h-1) (P less than 0.001). With refeeding TEF rose to a peak or plateau, then decreased to normal levels (61.9 +/- 36.0 kJ 2 h-1) before discharge from hospital. We conclude that the energy metabolism of adolescent girls adapts to semi-starvation by a reduction in both REE and TEF; with refeeding there is reversal of this adaptive function.

DNA methylation and expression of the genes coding for lactate dehydrogenases A and C during rodent spermatogenesis

The testis chromatin undergoes profound structural alterations and functional changes during spermatogenesis. Changes in DNA methylation have been correlated with gene expression in a number of systems, but the relationship between methylation and gene expression for testicular genes is unclear. To address this question, DNA methylation patterns and mRNA expression for a somatic form of lactate dehydrogenase (LDH), LDH-A, were compared with those of the testis-specific form, LDH-C, in preparations from testes of prepubertal and sexually mature mice, from isolated testicular cells, and from somatic tissues. At specific sites, LDH-A was less methylated in adult testis than in spleen DNA; the decreased methylation in the testicular DNA occurred as early as type A spermatogonia. In contrast, DNA methylation patterns for LDH-C did not differ between spleen and testis DNAs. In Northern blots, the levels of LDH-A transcripts were low in total testis RNA obtained from 6-12-day-old mice, and in type A and B spermatogonia from 8-day-old mice. LDH-A mRNA levels increased gradually in testes from 16-45-day-old mice. LDH-C transcripts were first detectable in the testes of 12-day-old mice and increased as spermatogenesis proceeded. Both LDH-A and LDH-C mRNA levels were low in preleptotene spermatocytes and leptotene/zygotene spermatocytes and increased substantially in pachytene spermatocytes and round spermatids. Reduced levels of LDH-A and LDH-C mRNAs were found in the residual bodies/cytoplasts fraction.(ABSTRACT TRUNCATED AT 250 WORDS)