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Biomedical subjects

M Lipp

Publications and source records attributed to M Lipp.

At least 91 records · Page 5Linked to original sources
PubMed1993

The G protein-coupled receptor BLR1 is involved in murine B cell differentiation and is also expressed in neuronal tissues.

The BLR1 gene, isolated initially from Burkitt's lymphoma cells (Eur. J. Immunol. 1992. 22: 2795), encodes a G protein-coupled receptor with significant relationship to receptors for chemokines (IL-8, MIP-1 alpha) and neuropeptides. The murine homologue of human BLR1 was cloned and used to investigate its expression in vivo. blr1-specific transcripts are observed in secondary lymphatic organs and to a lesser extent in brain of adult mice but not in other tissues. RNA in situ hybridization localizes blr1 transcription to primary follicles and to the mantle zone of secondary follicles. SCID mice in which mature B cell development is severely impaired exhibit a strongly reduced level of blr1-specific RNA in the spleen. The analysis of murine lymphoid tumor cell lines representing distinct stages of the B cell lineage reveals elevated expression of blr1 in B cell lymphomas but not in pre-B lymphomas or plasmacytomas. Induction of differentiation of resting B cells by cytokines or mitogens down-regulates expression of blr1. RNA in situ hybridization using brain sections of adult mice detects blr1 transcription in the granule and Purkinje cell layer of the cerebellum. Interestingly, the blr1 gene is also expressed during late embryogenesis in fetal liver and brain. In view of the remarkable expression pattern in the B cell lineage we suggest that murine BLR1 may represent a cytokine/neuropeptide receptor exerting regulatory functions on recirculating mature B lymphocytes.

Amino Acid Sequence↗
PubMed1993

Evaluation of the utility of interphase cytogenetics to detect residual cells with a malignant genotype in mixed cell populations: a Burkitt lymphoma model.

Interphase cytogenetics has been used to detect tumor cells in the presence of a large excess of normal cells. Probes for fluorescence in situ hybridization were chosen to reveal a specific hybridization pattern in tumor cell nuclei as well as to provide an internal control for the assessment of the hybridization results. By enumerating mixtures of cytogenetically normal cells and tumor cells from a Burkitt lymphoma cell line, we were able to detect tumor cells at a frequency of one in 500. Normal cells could be differentiated from Burkitt lymphoma cells with a specificity of approximately 99.9%.

Burkitt Lymphoma↗
PubMed1993

[Organizational forms of emergency medicine in international comparison].

The tasks of preclinical emergency medicine systems (PEMS) are to stabilize and maintain the vital functions and to guarantee qualified transport to the hospital. Worldwide, different structures exist as a result of historical developments. Legal regulations for PEMS have been introduced in most of the industrialized countries since 1960. More and more aspects have been subject to detailed regulations. PEMS are provided either by state-owned or by state-controlled (private) organisations. In most of the "underdeveloped" countries legal regulations do not exist and PEMS is often provided by social workers, by the army or by volunteers. In most countries, PEMS are financed by the state with a charge on the patient. In a few states PEMS are totally financed by the public health structure. Modern PEMS are controlled from dispatch centres which receive emergency calls (mostly by telephone) and send the appropriate rescue unit. In most states the staff of dispatch centres are paramedics; in some countries and in some urban areas physicians control the dispatch centre. In PEMS without physicians on the scene, an information exchange between the scene and the hospital can be observed frequently, in contrast to systems with physicians on the scene. Worldwide, ground-based PEMS are preferred, but in most countries an additional air rescue system has been established. The quality and quantity of the technical equipment of the ground-based PEMS differ widely: nationwide regulations exist, however, in the USA and Germany. Generally, there are two main concepts concerning the personnel structure: PEMS are either physician based or not. Requirements for emergency physicians differ greatly: in some countries no formal requirements exist, in others extensive practical and theoretical training is required.(ABSTRACT TRUNCATED AT 250 WORDS)

Emergency Medical Services↗
PubMed1993

[Fiberoptic intubation in the prone position. Anesthesia in a thoraco-abdominal knife stab wound].

An ambulance was dispatched to a 40-year-old man with a stab wound. On arrival, the emergency physician found the patient lying face down with a large knife protruding from his back between the scapula and spinal column (Fig. 1). The vital signs were stable (blood pressure 120/70 mmHg, heart rate 90 min, respiratory rate 25-30 min, oxygen saturation 94%); the estimated blood loss was 500 ml. Oxygen was administered and two i.v. lines were inserted. After light sedation (diazepam), the patient was transported to the clinic in the face-down position. X-ray films and physical examination showed that the knife, with a length of about 30 cm, had penetrated 15 cm into the thorax; the tip was located at the diaphragm (Fig. 2). Endotracheal intubation for the surgical revision was performed with the patient in the face-down position: after topical anaesthesia of the nasal mucosa (cocaine), a fiberoptic device was introduced. Additional topical anaesthetic (lignocaine) was applied through the biopsy channel onto the mucosa of the larynx and pharynx. After a sufficient waiting period, the endotracheal tube was pushed over the fiberoptic device into the trachea without problems (Fig. 3). During the entire period the patient was awake and breathing spontaneously; no coughing or change of body position occurred. After correct placement of the tube, general anaesthesia was induced. During positioning of the patient in the operating theatre, the knife was unintentionally dislodged and critical bleeding occurred. The situation could be controlled by immediate transfusions and rapid surgical revision, which revealed injuries to the lung, diaphragm, and stomach. The patient recovered without severe complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Abdominal Injuries↗
PubMed1992

Differentiation-specific expression of a novel G protein-coupled receptor from Burkitt's lymphoma.

Deregulation of the proto-oncogene MYC by specific chromosomal translocations has been shown to be essential but not sufficient for the development of Burkitt's lymphoma (BL). To identify other genes which either mark important steps in tumorigenesis or which reflect the cellular differentiation state of BL cells we have compared tumor cells to immortalized lymphoblastoid B cells by subtractive hybridization. We have identified a complementary DNA clone which encodes a novel member of the superfamily of GTP-binding (G) protein-coupled receptors, designated BLR1. The corresponding mRNA is expressed in BL and lymphatic tissues but not in other cell lines either of the B cell lineage or of other hematopoietic or non-hematopoietic origin. This exclusive expression of BLR1 and the oncogenic potential of this receptor class supports the hypothesis that BLR1 exerts a regulatory function in BL lymphomagenesis and/or B cell differentiation. Moreover, the protein sequence is highly related to that of receptors for the cytokine interleukin (IL)-8 and other neutrophil chemoattractants. We conclude that BLR1 may represent a potential candidate involved in the process of physiologic trafficking, cell-cell interactions, and activation of mature B lymphocytes in lymphatic tissues.

Amino Acid Sequence↗
PubMed1992

Specific metaphase and interphase detection of the breakpoint region in 8q24 of Burkitt lymphoma cells by triple-color fluorescence in situ hybridization.

Triple fluorescence in situ hybridization with a plasmid DNA library from sorted human chromosomes 8 in combination with bacteriophage clones flanking the breakpoint in 8q24 of the Burkitt lymphoma cell line J1 was used for the specific delineation of this breakpoint in individual tumor cells. With this approach, tumor-specific breakpoints in translocation chromosomes can be detected at all stages of the cell cycle with high specificity.

Burkitt Lymphoma↗
PubMed1992

Local anesthesia: a review.

Local anesthetics are the most widely administered drugs in dentistry. Significant advances have been made in past decades that have greatly increased both the safety and the efficacy of these important drugs. This paper reviews the history of local anesthesia, pharmacokinetics and clinical implications, techniques, complications, and future directions in the quest for more effective pain control in dentistry.

Anaphylaxis↗
PubMed1992

Management of an emergency: to be prepared for the unwanted event.

Every dental office needs an adequate emergency treatment structure. While theoretical and practical pregraduate education in emergency medicine is included (in differing degrees) in the curricula of dental schools throughout the world, postgraduate training is generally undertaken on a voluntary basis. Repeated training in emergency techniques is encouraged for the dentist and dental office staff, as the trained and coordinated action of the whole team in the dental office is necessary when an emergency occurs. Whenever possible, a recognized risk factor should be eliminated or its possible influence minimized prior to dental treatment. Patients requiring immediate dental therapy will need appropriate monitoring, adequate application of systemically acting drugs, or even treatment under standby conditions. Diagnostic equipment as well as equipment for monitoring the respiratory and cardiovascular systems should be available. Several monitors (blood pressure, ECG, and pulsoximetry) have been introduced to dentistry and have their indications in special patient groups. Clear therapeutic concepts are the endpoint of proper emergency management. The restoration of an undisturbed vital function has to be achieved, followed by detailed therapy. Dentists should refresh their knowledge of emergency treatment techniques and prepare themselves with therapeutic guidelines.

Dental Care for Persons with Disabilities↗
PubMed1992

Effects of different lidocaine sprays for topical anesthesia on cardiovascular parameters and oxygen saturation.

The effects of three lidocaine-containing solutions with and without frigen (freon-113) as a propellant on cardiovascular parameters and oxygen saturation, after different waiting periods and with different dosages applied, were investigated in 130 outpatients undergoing dental treatment in the maxilla under local anesthesia. They were divided randomly into five groups: (A) Xylocaine spray with frigen, two applications (20 mg lidocaine); (B) Xylestesin spray with frigen, two applications (14 mg lidocaine); (C) Xylestesin spray with frigen, three applications (21 mg lidocaine); (D) Xylestesin pump spray without frigen, two applications (14 mg lidocaine); and (E) no topical anesthesia. They were further divided into 12 subgroups to evaluate the influence of waiting periods between the application of the local anesthetic and the injection (1, 2, or 3 minutes). Without topical anesthesia and after the 1-minute waiting period, cardiovascular parameters increased immediately after the injection; after 2- and 3-minute waiting periods the increases were far less pronounced. The mean oxygen saturations did not change during the observed period. The higher lidocaine dosage administered (21 mg) did not intensify the positive impact on the cardiovascular parameters compared to the lower dosage (14 mg). The new pump spray without frigen proved to be as effective as the traditional, ecologically harmful aerosol sprays.

Adult↗
PubMed1992

Physical evaluation of the patient.

The physical evaluation of the patient before and during anesthesia and sedation is assuming an ever greater importance with the advent of sophisticated and reliable monitoring devices. This paper reviews the possible methods of evaluation and describes the types of mechanical monitors most suited to the dental office.

Anesthesia, Dental↗
PubMed1991

A novel divergently transcribed human histone H2A/H2B gene pair.

A genomic clone containing a novel closely linked human histone H2A/H2B gene pair has been isolated and sequenced along with extensive 5' and 3' flanking regions. Both genes are devoid of introns and code for core histone proteins. The nucleotide sequences are 84% and 87% homologous to the coding regions of a human genomic H2A and H2B gene, respectively. A comparison of the nucleotide-derived amino acid sequences shows that the histone H2A protein corresponds to the human H2A.1 subtype, whereas the H2B histone gene predicts an H2B protein sequence which is almost identical to the histone H2B.2 variant from human and bovine obtained by direct protein sequencing. The 3' flanking regions contain previously identified conserved sequence elements thought to be involved in transcription termination and processing of replication-dependent histone gene poly(A)- mRNAs. Primer extension analyses of the histone mRNAs encoded within this clone demonstrate that both genes are divergently transcribed from a 313 bp intergene promoter region. The spatial arrangement and orientation of two TATA-boxes, four CAAT-boxes, and one H2B-box within this region suggests that the linked genes share common promoter elements for transcriptional regulation.

Amino Acid Sequence↗
PubMed1991

[Various factors influencing the local anesthetic effect of articaine].

In a field study, the reduction in the anaesthetic effectiveness of Articain was investigated in relation to various influencing parameters. Both in the ZMK-Klinik (Dental Hospital) of Würzburg as well an in various independent practices, the local anaesthetic Articain was given to over 2000 patients in the course of dental treatment. With 12.1% of all test-subjects, inspite of the initial positive effectiveness upon application of the nerve-blocking anaesthetic, touch sensitivity and/or painfulness was established in the area concerned. Statistical evaluations of the recorded data of the test-subjects investigated showed a significantly higher quota of anaesthetic failure in the case of heavy cigarette consumption, chronic exposure to inhaled toxins as well as in the case of the intake of medicines of certain pharmaceutical types. Apart from that, a connection was also established between reduction in the effectiveness of the local anaesthetic and various treatments as well as the way in which the local anaesthetic was applied and the site of injection. Possible causes will be presented and discussed in relation to information from the literature on the subject.

Anesthesia, Dental↗
PubMed1991

[The use of the laryngeal mask--a practical method?].

In 1985 Brain et al. published their first experience with the laryngeal mask, developed by themselves. With this mask it is possible to seal the larynx and ventilate a patient during anesthesia without endotracheal intubation. Meanwhile, further reports of successful use have been published, especially in Great Britain. We decided to investigate this new anesthetic device. In 15 patients (ASA groups I and II) undergoing elective operations in the supine position the laryngeal mask was inserted after induction of anesthesia with propofol and alfentanil (Fig. 1). Positioning of the laryngeal mask was carried out as described by Brain. In all patients the laryngeal masks could be inserted without any problems, manual ventilation of the patient was performed immediately, and ventilating pressures never exceeded 15 cm H2O. We observed neither complications related to airway control nor technical problems. Cardiovascular parameters and arterial oxygen saturations were always in the normal range (Fig. 2). In 3 patients quick movements of the head were carried out during repositioning of a fractured zygomatic arch, but no complications due to a possible changed position of the laryngeal mask occurred. Postoperatively two patients reported airway complaints such as sore throat. Our investigation confirmed the previously described advantages of the laryngeal mask. We consider its use to be especially indicated in general anesthesia for short surgical or diagnostic procedures or if specific complications of endotracheal intubation should be avoided. A critical aspect in the use of the laryngeal mask is the fact that there is no complete isolation of the trachea and, therefore, an insufflation of the stomach or aspiration could occur, especially during critical situations (e.g. bronchospasms).(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesiology↗