Nucleotide sequence of 5S rDNA and localization of the ribosomal RNA genes to metaphase chromosomes of the Tilapiine cichlid fish, Oreochromis niloticus

In this study, we report the cloning and nucleotide sequence of PCR-generated 5S rDNA from the Tilapiine cichlid fish, Oreochromis niloticus. Two types of 5S rDNA were detected that differed by insertions and/or deletions and base substitutions within the non-transcribed spacer (NTS). Two 5S rDNA loci were observed by fluorescent in situ hybridization (FISH) in metaphase spreads of tilapia chromosomes. FISH using an 18S rDNA probe and silver nitrate sequential staining of 5S-FISH slides showed three 18S rDNA loci that are not syntenic to the 5S rDNA loci.

Evaluating, documenting and following up oral pathological conditions. A suggested protocol

BACKGROUND

Many textbooks and articles are available to assist dentists in examining patients, establishing diagnoses for oral lesions and understanding the techniques of biopsy. There is little guidance in the literature, however, on when and how to follow up lesions that have a low index of clinical suspicion, or for which the pathological diagnosis does not demonstrate any overt signs of malignancy or premalignancy.

TYPES OF STUDIES REVIEWED

The authors reviewed the literature, talked to numerous clinicians and sought legal opinions regarding how a reasonable and prudent dentist should manage patients with clinically evident oral lesions that do not suggest any adverse long-term effects on the health and safety of the patient.

RESULTS

The few guidelines available in the literature, coupled with the observations of the authors and others, allow logical and reasonable interim recommendations to be proposed regarding the frequency of examinations, the timing of invasive procedures and medicolegally prudent documentation guidelines. Future studies are needed to refine these recommendations.

CLINICAL IMPLICATIONS

Some dentists have been sued for alleged failure to monitor patients, document cases or refer patients with oral lesions. The recommendations provided here can help dentists manage these patients, but they should not be construed as being rigid guidelines or legal standards that apply to all clinical situations. In some cases, the judgment and experience of clinicians may indicate the need to deviate from these recommendations. Refinements of these guidelines may emerge on the basis of future studies.

Treatment of periodontal destruction associated with a cemental tear using minimally invasive surgery

BACKGROUND

A patient presented with moderate probing depth, pain on occlusal contact, and a fistula on a mandibular bicuspid. The probing depth increased 2 mm over a 3-month period despite relief of the occlusal trauma and resolution of the fistula. A radiograph showed an apparent separation of the cementum in the area of the pocket.

METHODS

The lesion was treated using a minimally invasive surgical approach to place a bone graft.

RESULTS

The probing depth was reduced to 2 mm with less than 1 mm of increased recession. A histologic examination of the damaged calcified tissue confirmed that it was cementum.

CONCLUSIONS

The increasing probing depth associated with a cemental tear seems to indicate that this phenomenon contributed to loss of attachment and bone. Removal of the detached cementum in combination with bone grafting using a minimally invasive surgical approach appears to have successfully corrected the periodontal destruction.

A randomized, double-blind placebo-controlled trial of moclobemide in patients with chronic fatigue syndrome

BACKGROUND

Chronic fatigue syndrome is characterized by prolonged and disabling fatigue and a range of neuropsychiatric symptoms including depressed and/or irritable mood. To date, no medical or psychotropic therapies have provided clear symptomatic benefit.

METHOD

Ninety patients with chronic fatigue syndrome, diagnosed with our system that approximates CDC criteria, participated in a randomized, placebo-controlled, double-blind trial of 450 to 600 mg/day of moclobemide, a novel reversible inhibitor of monoamine oxidase-A.

RESULTS

Fifty-one percent (24/47) of patients receiving moclobemide improved compared with 33% (14/43) of patients receiving placebo (odds ratio = 2.16, 95% confidence interval [CI] = 0.9 to 5.1). Drug response was best characterized symptomatically by an increase in the subjective sense of vigor and energy rather than a reduction in depressed mood. The effect of moclobemide on subjective energy was detectable within the first 2 weeks of treatment and increased across the course of the study. The greatest reduction in clinician-rated disability was in patients with concurrent immunologic dysfunction (mean difference in standardized units of improvement = 0.8, 95% CI = 0.03 to 1.6).

CONCLUSION

Moclobemide produces some improvement in key symptoms experienced by patients with chronic fatigue syndrome. This effect is not dependent on the presence of concurrent psychological distress and is likely to be shared with other monoamine oxidase inhibitors.

Choosing a first-line drug in the management of elevated blood pressure: what is the evidence? 3: Angiotensin-converting-enzyme inhibitors

Elevated blood pressure is associated with an increased risk of cardiovascular illness and death. Efforts to reduce that risk have led to recommendations for a wide array of nondrug and drug therapies. Choosing the optimal first-line drug for hypertensive patients should address a hierarchy of treatment goals: decrease in morbidity and mortality associated with hypertension, decrease in blood pressure and other surrogate markers, good tolerance, dosing convenience and low cost. This article examines the evidence for angiotensin-converting-enzyme (ACE) inhibitors as a class of first-line antihypertensive drugs in light of these treatment goals. Overall, the evidence does not support the use of ACE inhibitors as first-line drugs in the management of most patients with hypertension, although they have proven benefit as second-line drugs for the treatment of congestive heart failure and left ventricular dysfunction secondary to myocardial infarction.

Surgical management of posterior shoulder instability in a ten-year-old boy: a case report and literature review

Posterior shoulder instability is an uncommon clinical entity. It is even more rare in the pediatric population. We report the case of a 10-year-old boy who experienced recurrent posttraumatic posterior shoulder instability that eventually required surgical intervention. A review of the literature revealed no previous report of surgical management of nonobstetrical posttraumatic posterior glenohumeral instability in a skeletally immature individual.

Choosing a first-line drug in the management of elevated blood pressure: what is the evidence? 2: Beta-blockers

Elevated blood pressure is associated with an increased risk of cardiovascular illness and death. Efforts to reduce that risk have led to recommendations for a wide array of nondrug and drug therapies. Choosing the optimal first-line drug for hypertensive patients should address a hierarchy of treatment goals: decrease in morbidity and mortality associated with hypertension, decrease in blood pressure, good tolerance, dosing convenience and low cost. This article examines the evidence for beta-blockers as a class of first-line antihypertensive drugs in light of these treatment goals. The evidence indicates that beta-blockers are probably not as effective in reducing morbidity and mortality as low-dose thiazide diuretics and that there may be significant differences in effectiveness among various beta-blockers.

Choosing a first-line drug in the management of elevated blood pressure: what is the evidence? 1: Thiazide diuretics

Elevated blood pressure is associated with an increased risk of cardiovascular illness and death. Efforts to reduce that risk have led to recommendations for a wide array of nondrug and drug therapies. Choosing the optimal first-line drug for hypertensive patients should address a hierarchy of treatment goals: decrease in morbidity and mortality associated with hypertension, decrease in blood pressure, lack of effect on patients' quality of life, dosing convenience and low cost. This article examines the evidence for thiazide diuretics as a class of first-line antihypertensive drugs in light of these treatment goals. The evidence indicates that low-dose thiazides are preferable to high-dose thiazides and that low-dose thiazides are better than or equivalent to other antihypertensive drugs for each of the goals of therapy.

Protein-degrading enediynes: library screening of Bergman cycloaromatization products

[structure: see text] A screening method based on Bergman cycloaromatization products was applied to a compact library of estrogenic-enediyne hybrids. An enediyne candidate identified from the screen was subsequently synthesized, and it induced temperature- and concentration-dependent degradation of human estrogen receptor alpha upon cycloaromatization.

Nucleotide sequence of cDNA clones coding for a brain-type fatty acid binding protein and its tissue-specific expression in adult zebrafish (Danio rerio)

We have determined the nucleotide sequence for two cDNA clones coding for a fatty acid binding protein (FABP) from zebrafish (Danio rerio). Comparison of the sequence with GenBank entries revealed extensive amino acid identity between this zebrafish FABP and brain FABPs (B-FABP) from other species. The zebrafish B-FABP cDNA hybridized to single restriction fragments of total zebrafish genomic DNA digested with the restriction endonucleases BglII or EcoRI suggesting that a single copy of the B-FABP gene is present in the zebrafish genome. Northern blot analysis demonstrated that the zebrafish B-FABP mRNA is approximately 850 nucleotides in length. In situ hybridization revealed that the B-FABP mRNA was expressed in the periventricular gray zone of the optic tectum of the adult zebrafish brain.

cDNA sequence and tissue-specific expression of a basic liver-type fatty acid binding protein in adult zebrafish (Danio rerio)

We have determined the nucleotide sequence for a cDNA clone derived from zebrafish (Danio rerio) that codes for a fatty acid binding protein (FABP). Amino acid sequence similarity of the zebrafish FABP was highest to FABPs isolated from the livers of catfish, chicken, salamander and iguana. The open-reading frame of the zebrafish FABP cDNA codes for a protein of 14.0 kDa with a calculated isoelectric point of 8.8. The zebrafish liver-type FABP (L-FABP) cDNA hybridized to single restriction fragments of total zebrafish genomic DNA digested with the restriction endonucleases HaeIII or EcoRI suggesting that a single copy of the L-FABP gene is present in the zebrafish genome. Northern blot analysis demonstrated that the zebrafish L-FABP cDNA hybridized to a transcript of 700 nucleotides in total zebrafish RNA. In situ hybridization and emulsion autoradiography revealed that the L-FABP was expressed exclusively in the liver of the adult zebrafish. Based on amino acid sequence similarity, the isoelectric point and its tissue-specific pattern of expression, we conclude that this zebrafish FABP belongs to the basic liver-type FABPs only found, thus far, in non-mammalian vertebrates.

Involvement of GIRK2 in postnatal development of the weaver cerebellum

We demonstrate that the homozygous weaver granule neurons cultured on a laminin substratum fail to express inwardly rectifying potassium currents, including a functional G-protein coupled inwardly rectifying potassium (GIRK)2 potassium channel. By contrast, both normal and weaver Purkinje cells express inwardly rectifying potassium currents, and normal granule cells exhibit inwardly rectifying potassium currents inducible with GTP-gamma-S. In protein extracts of the vermal postnatal day (P)5-9 weaver cerebellum, the GIRK2 protein could not be detected by Western analysis, although the GIRK2 protein was detectable in extracts of the normal vermis. Northern analysis indicated that during early postnatal cerebellar development, the GIRK2 mRNA is expressed at extremely low levels being detectable at P18-23 in the normal but not yet in the homozygous weaver cerebellum. Using reverse transcriptase-polymerase chain reaction (RT-PCR), the GIRK2 mRNA was detected in both normal and weaver cerebella, but quantitative PCR confirmed that the weaver cerebellum expressed the GIRK2 gene at significantly lower levels as compared to the normal cerebellum (P = 0.01, paired t-test). Sequencing indicated that the weaver GIRK2 channel gene had the point mutation proposed to be responsible for the weaver phenotype. Rescue of both survival and neurite outgrowth of the cultured vermal weaver granule neurons by verapamil (Liesi and Wright, 1996; Liesi et al., 1999) induced expression of immunocytochemically detectable levels of the GIRK2 protein. Sequencing revealed that the GIRK2 mRNA of the rescued weaver granule neurons remained the mutated variant of the GIRK2 channel gene. Our results indicate that expression of the mutated GIRK2 protein and/or mRNA in the weaver granule neurons may be an indicator of rescue rather than death of the weaver granule neurons. That the weaver granule neurons expressed no functional GIRK2 receptors during a time period of neuronal death and migration failure suggests that the point mutation in the H5 membrane spanning region of the GIRK2 gene may associate with, but not be responsible for the weaver phenotype.

Understanding enediyne-protein interactions: diyl atom transfer results in generation of aminoacyl radicals

[formula: see text] The origin of the protein modulating capacity of enediynes has been probed. A series of synthetic enediyne-derived diyls participated in atom transfer chemistry with a labeled amino acid. Subsequent experiments suggest that diyl radicals may modulate protein architecture via formation of captodatively stabilized radicals.

Nucleotide sequence of a cDNA clone coding for an intestinal-type fatty acid binding protein and its tissue-specific expression in zebrafish (Danio rerio)

We have cloned a cDNA from zebrafish (Danio rerio) that contains an open-reading frame of 132 amino acids coding for a fatty acid binding protein (FABP) of approximately 15 kDa. Multiple sequence alignment revealed extensive amino acid identity between this zebrafish FABP and intestinal-like FABPs (I-FABP) from other species. The zebrafish I-FABP cDNA hybridized to single restriction fragments of total zebrafish genomic DNA digested with the restriction endonucleases PstI Bg/II or EcoRI suggesting that a single copy of the I-FABP gene is present in the zebrafish genome. An oligonucleotide probe complementary to the zebrafish I-FABP mRNA hybridized to an mRNA of approximately 800 bases in Northern blot analysis. In situ hybridization revealed that the I-FABP mRNA was expressed exclusively in the intestine of the adult zebrafish.

A 59 amino acid insertion increases Ca(2+) sensitivity of rbslo1, a Ca2+ -activated K(+) channel in renal epithelia

We previously cloned a MaxiK channel alpha-subunit isoform, rbslo1, from rabbit kidney with an amino acid sequence highly homologous to mslo but with a 59 amino acid insertion between S8 and S9 (Morita et al., 1997. Am. J. Physiol. 273:F615-F624). rbslo1 activation properties differed substantially from mslo with much greater Ca2+ sensitivity, half-activation potential of -49 mV in 1 micron m Ca2+. We now report single-channel analysis of rbslo1 and delA, a construct produced by removal of the 59 amino acid insertion at site A. delA is identical to mslo from upstream of S1 to downstream of S10 with the exception of 8 amino acids. Slope of the steady-state Boltzmann voltage activation curve was 8.1 mV per e-fold change in probability of opening for both rbslo1 and delA. The apparent [Ca2+](i) properties in delA were more like mslo but the voltage-activation properties remained distinctly rbslo1. Ca2+ affinity decreased and transmembrane voltage effects on apparent Ca2+ affinity increased in delA. The differences between rbslo1 and other cloned channels appear to be localized at insertion site A with both the insertion sequence and amino acid substitutions near site A being important. The steeper activation slope makes the channel more responsive to small changes in transmembrane voltage while the insertion sequence makes the channel functional at physiological low levels of [Ca2+](i).

Neurotoxicity of isoniazid and its metabolites in cultures of mouse dorsal root ganglion neurons and hybrid neuronal cell line

Isoniazid (INH) is one of the anti-tuberculosis drugs widely prescribed for patients since the early 1950s. It is relatively nontoxic but some patients develop peripheral neuropathy attributed to a disturbance of vitamin B6 metabolism. Some isoniazid metabolites are hepatotoxic but little is known about their neurotoxic property. Isoniazid and its metabolites including acetylisoniazid, acetylhydrazine, diacetylhydrazine, isonicotinic acid and hydrazine were examined for their potential neurotoxic effects in cultured mouse dorsal root ganglion (DRG) neurons and mouse neuroblastoma x DRG neuron hybrid cell line N18D3. Isoniazid did not cause neurotoxicity at exposures up to 7 days. Hydrazine was found to be the most toxic metabolite with LC50 values of 2.7 mM and 0.3 mM after 7 days of exposure in DRG neurons and N18D3 hybrid neurons, respectively. Other metabolites including acetylisoniazid, acetylhydrazine, diacetylhydrazine and isonicotinic acid had moderate to minor neurotoxic effects on N18D3 hybrid neurons. Pyridoxine, which is used in clinical practice to prevent or ameliorate the isoniazid-induced neuropathy, did not consistently reverse the neurotoxicity of any of the metabolites in the cell cultures, but some interaction with hydrazine cannot be ruled out. Pyridoxine itself was found to be neurotoxic both in DRG neurons and N18D3 hybrid neurons, in agreement with human peripheral sensory neuropathy caused by prolonged overdosage. The enzymes catalase and superoxide dismutase and the antioxidant agent selenium showed some protection against hydrazine neurotoxicity, suggesting an involvement of the generation of reactive oxygen species in the pathogenesis of isoniazid neuropathy. Both mouse DRG neurons and N18D3 mouse hybrid neurons were shown to be useful culture systems for elucidating the neurotoxicity mechanisms of agents causing sensory neuropathies and general neurotoxic effects in the nervous system.

A LINE2 repetitive DNA sequence from the cichlid fish, Oreochromis niloticus: sequence analysis and chromosomal distribution

We report the cloning and characterization of a long interspersed nucleotide element (LINE) from a cichlid fish, Oreochromis niloticus, and show the distribution of this element, called CiLINE2 for cichlid LINE2, in the chromosomes of this species. The identification of an open reading frame in CiLINE2 with amino acid sequence similarity to reverse transcriptases encoded by LINE-like elements in Caenorhabditis elegans, Platemys spixii, Schistosoma mansoni, Gallus gallus (CRI), Drosophila melanogaster (I factor), and Homo sapiens (LINE2), as well as the structure of the element, suggest it is a member of this family of non-long terminal repeat-containing retrotransposons. Search of a DNA sequence database identified sequences similar to CiLINE2 in four other fish species (Haplotaxodon microlepis, Oreochromis mossambicus, Pseudotropheus zebra, and Fugu rubripes). Southern blot hybridization experiments revealed the presence of sequences similar to CiLINE2 in all Tilapiini species analyzed from the genera Oreochromis, Tilapia, and Sarotherodon, and gave an estimated copy number of about 5500 for the haploid genome of O. niloticus. Fluorescent in situ hybridization showed that CiLINE2 sequences were organized in small clusters dispersed over all chromosomes of O. niloticus, with a higher concentration near chromosome ends. Furthermore, the long arm of chromosome 1 was strikingly enriched with this sequence. The distribution of LINE2-related elements might underlie the difference in chromosome banding patterns observed between cold-blooded vertebrates and mammals.

Evaluation of the use of calendar blister packaging on patient compliance with STD syndromic treatment regimens

BACKGROUND

Good compliance with antibiotic therapy is critical for successful management of sexually transmitted diseases (STDs).

GOAL OF THIS STUDY

To evaluate the use of user-friendly drug packaging as a means of improving patient compliance with STD therapy and the acceptability of the packaging.

STUDY DESIGN

Compliance of patients with STDs with treatment regimens for three different STD syndromes, using antibiotics packed in standard medicine packaging (SP), was compared to that of patients using calendar blister packaged drugs. Compliance was measured by counting the remaining pills at two return visits. Questionnaires were used to evaluate acceptability of the packs.

RESULTS

Compliance was significantly better among patients using the calendar blister packs than among those using standard packs, irrespective of dosing frequency. The degree of poor compliance increased with increasing dosing frequency. There was a high level of satisfaction with the blister pack among patients and health care workers.

CONCLUSION

Compliance can be improved by the introduction of user-friendly drug packaging, especially for more complex dosing regimens.

Idiopathic scoliosis. The clinical value of radiologists' interpretation of pre- and postoperative radiographs with interobserver and interdisciplinary variability

STUDY DESIGN

A retrospective analysis of radiographic reports of 161 consecutive patients with idiopathic scoliosis at the authors' institution.

OBJECTIVES

To compare various radiographic findings that directly affect surgical decision-making and the evaluation of postsurgical outcomes to determine the usefulness of information gathered from radiologists' multiple duplicate reading of films.

SUMMARY OF BACKGROUND DATA

To the authors' knowledge, there are no previous studies on the readings of scoliosis films by radiologists and surgeons.

METHODS

The patient pool was drawn from the private practices of two board-certified orthopaedic surgeons. Each set of radiographs was read by one of seven board-certified radiologists and by one of the two surgeons. The two reports of each radiograph were compared. The factors included in the reports were scoliosis deformity, scoliosis type, curve progression, curve magnitude, levels of the curve, kyphosis, lordosis, the presence of instrumentation, and the presence of a fusion.

RESULTS

The radiologists and orthopedic surgeons mentioned the presence of scoliosis in 95% and 99.4% of their reports, respectively. The type of scoliosis was mentioned in 5% of reports by radiologists and in 99.4% by orthopedists. Progression of the curve was documented in 16.7% of the radiologists' reports and in 98.4% of orthopedists' reports. The magnitude of the curve was stated in 12.6% of the radiologists' reports, compared with 98.1% of the orthopaedists' reports. The levels of the curve were documented in 10.6% and 95.6% of reports by the radiologists and orthopedists, respectively. Radiologists mentioned kyphosis and lordosis in 28% and 26.5% of reports, respectively. These same two entities were mentioned in 98.2% and 79.4% of reports by the orthopedists. Finally, the radiologists noted the presence of instrumentation and of a fusion in 77.8% and 68.3% of reports, respectively. Orthopedists mentioned these same two entities in 84.4% and 100% of reports, respectively. In the radiologists' reports on the presence of instrumentation, 20% were mislabeled or improperly identified. Seven percent of the fusions documented by the radiologists were incorrect because they were recorded before biologic fusion could have taken place. In all these categories, the radiologists provided information in excess of the orthopedic reports a total of 1.9% of the time. Of this 1.9% additional information, 36.8% was incorrectly read or mislabeled. The other 63.2% of the additional information (1.9% of the total) did not elucidate anything of real clinical significance that was missed by the orthopedic surgeons (e.g., a tumor in the lung).

CONCLUSIONS

These findings show that the attending orthopedic spine surgeons gained little useful information from the radiologists' multiple duplicate reading of films.