Syrian hamster 5S rRNA genes are assigned to 6q2 with PNA-FISH by an R-banded karyotype.

A karyotype for the Syrian hamster is proposed based on an R-banding pattern. R-bands were obtained by BrdU incorporation into the cells followed by a combined DAPI and propidium iodide staining of the fixed metaphase spreads. In situ hybridisation was performed with two biotinylated 18-mer PNA (peptide nucleic acid) probes complementary to sequences within the 5S rRNA gene. The 5S rRNA gene repeats map to chromosome 6q2. The present PNA-FISH procedure is an abbreviated and simpler version of that previously published.

Mink 5S rRNA genes map to 2q in three loci suggesting conservation of synteny with human 1q.

By in situ hybridization we show that the SS rRNA genes in the mink map to chromosome 2q in three loci. The 2q1.1 locus containing 34% of the 5S rDNA, maps close to the centromere, and the remaining two loci of the 5S rDNA map to 2q1.3 (52%) and to 2q2.3. (14%). These data were obtained with a tritiated transcript of the 5S rRNA gene containing 121 bp. In a comparative FISH study performed with a biotinylated transcript of the 5S rRNA gene the procedure failed to detect the 2q2.3 site. A closely corresponding difference between the two procedures experienced previously in man and in the crab-eating macaque is discussed. The present results suggest a homology between 2q in the mink and part of 1q in man harbouring the 5S rRNA genes in 1q42.13 and 1q31, respectively.

The rat 5S rRNA bona fide gene repeat maps to chromosome 19q12-->qter and the pseudogene repeat maps to 12q12.

The bona fide 5S rRNA genes in the rat are found in a 1.8-kb tandem repeat and the pseudogenes occur in a 2.5-kb tandem repeat. Three bona fide 5S rRNA genes and one gene variant with one base substitution in the coding region were isolated from the 1.8-kb repeat. Six pseudogenes were isolated from the 2.5-kb repeat. The total number of genes/gene variants/pseudogenes is 700-1200 copies per haploid genome, and the pseudogene repeat contains about 50% more 5S rDNA related sequences compared with the bona fide gene repeat. Various well-defined 5' - and 3'-flanking sequences of the bona fide gene and of the pseudogene were used for in situ hybridization to metaphase chromosomes. The results showed that the bona fide 5S rRNA gene repeat Rn5s maps to chromosome 19q12 and the pseudogene repeat Rn5sp maps to 12q12.

Additional assignment of the human 5S rRNA genes to chromosome region 1q31.

A major fraction of the human 5S rRNA genes has previously been assigned to chromosome region 1q42.11-->q42.13 (Sørensen et al., 1991). Through in situ hybridization of different tritiated probes to metaphase spreads, we have demonstrated that a minor fraction of the 5S rRNA genes is localized at band 1q31. This fraction amounts to 25-30% of the genes found in the region 1q42.11-->q42.13. Results obtained with the chromosomes of a balanced translocation carrier involving this region indicate that the major cluster is localized in band 1q42.13.

Transcription of human 5S rRNA genes is influenced by an upstream DNA sequence.

Six human 5S rRNA genes and gene variants and one pseudogene have been sequenced. The six genes/variants were transcribed in a HeLa cell extract with about equal efficiency. Three genes contain the Sp1 binding sequence GGGCGG in position -43 to -38 and three genes contain the Sp1 like sequence GGGCCG in this position. The six genes contain furthermore one Sp1 binding site in a position about -245 and one ATF recognition site in a position about -202. A 12 bp sequence (GGCTCTTGGGGC) found in position -32 to -21 strongly influenced the transcriptional efficiency in vitro. This 12-mer, designated the D box, has also been found upstream a 5S rRNA gene from hamster and mouse. Removal of the Sp1 binding sites had no effect on the transcription in vitro whereas the transcriptional efficiency decreased to 10% if the D box was removed from the human 5S rRNA gene.

Fine mapping of human 5S rRNA genes to chromosome 1q42.11----q42.13.

The human 5S rRNA genes have been localized by in situ hybridization to metaphase chromosomes. Tritiated RNA probes were made by transcription from 2.300-bp and 638-bp DNA fragments containing an isolated human 5S rRNA gene. Hybridization to metaphase spreads from a balanced reciprocal translocation carrier, 46,XX.t(1:7)(q42.13;p11.1), showed that the 5S rRNA genes were entirely localized on the normal and the derivative chromosome 1. This narrows the chromosome position of the major fraction of 5S rRNA genes and pseudogenes to the region 1q42.11----q42.13.

Optimization of in situ hybridization to human metaphase chromosomes.

A simplified method describing optimal conditions for in situ hybridization to human chromosomes is presented. A 1.5-kb DNA fragment coding for part of the 28 S rRNA was subcloned into pSP65. Tritium-labeled RNA was synthesized as runoff transcripts and 39-67% of the labeled probes specifically hybridized to the nucleolar organizer regions of the acrocentric chromosomes. Denaturation performed with 70% formamide, 1 mM EDTA, 2 X SSC gave a high specific hybridization with both fresh chromosome spreads (1-8 weeks) and older preparations (3-6 months). To obtain good chromosome morphology and a high specific hybridization it was important to neutralize the final formamide denaturation mixture containing 70% formamide, 1 mM EDTA, and 2 X SSC, whereas it was unimportant to deionize the formamide. Freshly made slides denatured with 0.15 M NaOH in 70% ethanol hybridized equally well with the rRNA probe. Despite treatment of the chromosomes with RNases before denaturation the following proteinase K and the acetylation steps recommended could be omitted without degradation of the rRNA probe as judged from the high specific hybridization to the nucleolar organizer regions.

Detection of a few picograms of DNA on polyacrylamide gels by silver staining.

DNA fragments separated on polyacrylamide gels are silver stained in ethanolamine solution. The staining procedure can be completed in 3 1/2 h. Illumination of the gels on a black background increases the sensitivity of detection compared with the usual transillumination. The limit level of detection is 3-5 pg per band with a cross-sectional area of 5 mm2. Five to fifty picograms of DNA may be detected quantitatively by scanning the gels. The method will detect 0.1 to 1 ng per band of low-molecular-weight RNA components.

The effect of pH on silver staining of nucleolus organizer regions.

The effect of pH on silver staining of the nucleolus organizer regions (NORs) of human chromosomes has been investigated between pH 6.5 and 12.0. Nonvolatile mixtures of ethanolamine and ethanolammonium nitrate replaced the ammonia of standard procedures. The optimal NOR staining obtained at pH 3.5 by the silver staining procedure of Howell and Black served as a standard; this procedure stained all ten NORs in 90% of mitoses. Similar NOR staining was found in 75% of mitoses stained at pH 11.7 or 11.8, but only in 10-15% of mitoses stained between pH 11.6 and 10.0. Between pH 10.0 and 9.0 NOR staining was incomplete, and between pH 8.5 and 6.5 there was no NOR staining.

Spinal or general anaesthesia for surgery of the fractured hip? A prospective study of mortality in 578 patients.

The mortality following surgical correction of upper femoral fractures was investigated in 578 patients, over the age of 50 yr, randomly allocated to receive spinal (bupivacaine) or general (enflurane or neurolept) anaesthesia. Thirty days after surgery the mortality was 6% after spinal and 8% after general anaesthesia (ns). Six months to 2 years after surgery the mortality was identical in the two groups. There were no differences with respect to ambulation and discharge. The estimated blood loss was smaller (P less than 0.05) in patients receiving spinal anaesthesia. Regardless of the anaesthetic technique, a high short-term mortality was related to age, male sex, and trochanteric fracture, whereas excess long-term mortality was related to male sex and high ASA scores.

Immediate and long-term mental recovery from general versus epidural anesthesia in elderly patients.

The postoperative course of mental performance during the first week and at 3 months after operation was studied in 30 patients above the age of 60, undergoing total hip replacement arthroplasty. The patients were randomly allocated to receive either general anesthesia, epidural analgesia, or general anesthesia plus epidural analgesia. The surgically induced increase in plasma cortisol and glucose was inhibited in the two groups receiving epidural analgesia. Mental performance was studied with psychological methods. An equal degree of postoperative impairment of mental performance of 3-4 days' duration was found in all groups. Three months after surgery, mental function had improved slightly and to the same extent in all groups. We conclude that the after surgery, mental function had improved slightly and to the same extent in all groups. We conclude that the transient mental impairment occurring within the first postoperative week is caused by factors other than general anesthetic agents and the endocrine-metabolic response to surgery.

Atropine before enflurane anaesthesia: effects on cardiac rhythm, pulse rate, blood pressure and airway secretion.

The occurrence of cardiac arrhythmias and changes in pulse rate and blood pressure during mask anaesthesia with enflurane was investigated in 92 patients with special reference to the influence of atropine (0.01 mg kg-1 5 min before anaesthesia) and thiopental. The average duration of anaesthesia was a little less than 1 h in all four groups. More than five ventricular extrasystoles occurred in one patient (38 min after atropine). Supraventricular (mainly nodal) arrhythmias were significantly (P less than 0.005) more common in the atropine groups (15/45) than in the non-atropine groups (4/47). Following atropine, heart rate increased by about 25 beats min-1, whereas only very slight increases were seen in the non-atropine groups. Blood pressure fell at the induction but was almost back to normal at the end of anaesthesia. Blood pressure was unaffected by atropine. Slightly lower values of blood pressure were suggested in the thiopental groups, whereas thiopental did not modify cardiac rhythm or pulse rate. Suction of the pharynx was necessary in only one patient. In conclusion, the present study does not support the routine administration of atropine before enflurane anaesthesia with or without thiopental induction.

Halothane anaesthesia with spontaneous respiration for tonsillectomy in children.

Bains's anaesthetic circuit was used in 22 children undergoing tonsillectomy under halothane anaesthesia with spontaneous respiration. End-tidal CO2 was monitored by capnography. The median maximum end-tidal CO2 was 7%, and during surgery nine patients had an end-tidal CO2 higher than 7%, corresponding to a Paco2 close to 8 kPa when the arterial to end-tidal CO2 difference is taken into consideration. Increase in fresh gas flow or change to a non-rebreathing system had virtually no effect on end-tidal CO2. However, following discontinuation of halothane or during controlled respiration, acceptable values of end-tidal CO2 were reached, leading to the conclusion that respiratory depression was responsible for the high values of end-tidal CO2 rather than properties of Bain's circuit or too low gas flow rates.

Arterial to end-tidal carbon dioxide tension difference in children under halothane anaesthesia.

Using blood gas determinations and capnography, the relationship between arterial and end-tidal PCO2 was investigated in 20 children under halothane anaesthesia with spontaneous respiration. A median arterial to end-tidal carbon dioxide tension difference of 0.66 kPa (5 mm Hg) was found. There was a close correlation between PaCO2 and the magnitude of the carbon dioxide difference. Our findings may largely be explained by an increase in VD/VT (presumably mainly due to a reduction of VT) causing admixture of dead space air throughout expiration. It is concluded that though end-tidal carbon dioxide does not exactly reflect PaCO2 capnography may be of value as a monitor of respiration in paediatric anaesthesia at normal or near-normal values of end-tidal carbon dioxide.

[Impression and assessment of anesthesia by patients. An interview study]. / Patienternes oplevelse og vurdering of anaestesi. En interviewundersøgelse.

PIP: Both inpatients and outpatients were interviewed, 720 prior to receiving anesthesia and 679 after anesthesia for planned operations. On the average, 84% of the patients had been anesthesized previously and 21% of these had unpleasant memories of these episodes. Slightly more than 1/2 of the inpatients were anxious preoperatively but at the postoperative interview, 86% stated that they felt calm at the induction of anesthesia. The role of premedication here is debatable as the same reduction in preoperative anxiety was observed among the outpatients who did not receive premedication. Fewer than 1/2 of the patients in whom the intervention was performed under local anesthesia would have preferred general anesthesia instead. Satisfaction was lowest with local analgesia as only 77% desired the same form of anesthesia again. The greatest satisfaction was expressed among patients in whom outpatient termination of pregnancy was undertaken (96%). Patients who underwent pregnancy termination were just as anxious preoperatively and postoperatively and expressed a great desire for general anesthesia as the patients who were to undergo much more serious interventions. Over 1/3 of the patients had sore throats following intubation. Postoperative respirator therapy did not result in increased incidence of sore throats. (author's modified)^ieng

Paroxetine: pharmacokinetics, tolerance and depletion of blood 5-HT in man.

The tolerance of paroxetine (FG 7051), as well as its pharmacokinetics and reduction of 5-HT in blood, has been investigated in man. Three normal, healthy volunteers were administered the single doses 10, 25, 50, and 75 mg orally, and three volunteers received 10, 25, and 50 mg per day for seven or fourteen days. No toxic effect on blood, kidney, liver, heart or general condition was found by chemical and physical examinations. The pharmacokinetic studies revealed a dose dependent systemic availability, a rather slow elimination (t1-z2 = approximately 16 hrs), a good fit to one compartment open model, and an almost complete metabolism of the substance. 25 mg paroxetine per day gave a maximal reduction of 5-HT in the blood within 2--3 weeks (to approximately 0.03 microgram/ml). The 5-HT levels returned to the basic levels during a three to four weeks drug-free period.