Biomedical subjects

J Mayer

Publications and source records attributed to J Mayer.

At least 127 records · Page 7Linked to original sources

PubMed1998

[Must we be really concerned about amphotericin B toxicity in oncology patients?].

BACKGROUND: Amphotericin B treatment in oncological patients is irrepaceable due to the high frequency of mycotic infections. From data in the literature ensues that the most serious undesirable effect of amphotericin B is nephrotoxicity, manifested by a reduced glomerular filtration and impaired tubular function (in particular the development of hypokalemia, and hypomagnesaemia). Prophylaxis of nephrotoxicity is despite major efforts unsatisfactory. In the submitted work the authors tested in a major group of patients their working hypothesis based on previous observations, that prophylactic replacement of the increasing ion losses in urine during amphotericin B treatment without waiting for a decline of serum concentrations of these ions, along with adequate hydration delays or eliminates the decline of glomerular functions. METHODS AND RESULTS: During amphotericin B therapy of 25 oncological patients renal functions, Na, K and Mg urinary excretion and the serum concentrations of these ions were followed up in detail. The urinary losses were replaced. No overall prophylaxis to prevent acute toxic reactions associated with administration of the drug was used. The mean dose of amphotericin B was 0.82 mg/kg, the mean diuresis 3662 ml/24 hours. Acute toxic reactions calling for hydrocortisone administration were observed only in 6% of the patients. During treatment the urinary K and Mg losses increased significantly and had to one replaced. There was also a significant increase of the excretory fractions of K and Na. However there were no significant changes of serum ions nor a rise of creatinine. The creatinine clearance even increased slightly though insignificantly (1.384 ml/s as compared with 1.392 ml/s). CONCLUSIONS: Consequential hydration of patients and prophylactic replacement of urinary ion losses during amphotericin B therapy are effective in preventing ion disbalances and a decline of glomerular functions. Acute toxic reactions associated with administration of amphotericin B are infrequent.

Amphotericin B↗

PubMed1998

[Chemotherapy of resistant and recurrent lymphoma based on a combination of ifosfamide and etoposide. Antitumor effects, toxicity and stimulation of peripheral stem cells].

BACKGROUND: Treatment of Hodgkin's disease (HD) and non-Hodgkin lymphomas (NHL) is still unsatisfactory in patients resistant to primary therapy or those with early relapses. The objective of the trial was to test whether salvage regimens based on a combination of iphosphamide and etopozide have a sufficient anti-lymphoma effect, while the toxicity is still acceptable, and in conjunction with growth factors as satisfactory mobilizing potential for the collection of peripheral stem cells (PBSC). METHODS AND RESULTS: A group of 40 patients with relapsing and/or primary therapy resisting lymphomas (14 NHL, 26 HD) were treated by life saving or stimulating chemotherapy VIM (etopozide, iphosphamide, methotrexate) and MINE (iphosphamide mitoxanthrone, etopozide; mostly NHL). If the response to these regimes was inadequate, to some patients in addition mini (dexa) regimes were administered, BEAM and DHAP resp., with the objective to achieve maximum reduction of the tumourous mass before high-dosage treatment with the support of autologous PBSC. The authors administered 119 cycles of salvage chemotherapy (51 VIM, 46 MINE, 22 mini-dexa-BEAM and DHAP). The toxicity of chemotherapy and the therapeutic response were evaluated according to WHO criteria. The toxicity of VIM and MINE, with the exception for mobilization of desirable transient leukopenia, was not serious. During stimulation of PBSC on average three leukophereses were made and on average 9.9. 10(6) CD34+ cells/kg body weight of the patient were obtained and 53.2. 10(4) CFU-GM/kg (VIM), and 13.5. 10(6) CD34+ cells/kg 53.4. 10(4) CFU-GM/kg (MINE) resp. A total of 64% (MINE) and 61% (VIM) therapeutic responses were obtained, 14% (MINE) and 26% (VIM) complete remissions and 50% (MINE) and 35% (VIM) partial remissions. CONCLUSIONS: Life saving regimes, VIM and MINE, have a good antilymphoma activity, low toxicity and in combination with growth factors (filgrastim) they ensure a good collection of PBSC. As compared with other regimens, in particular for stimulation, VIM and MINE appear to be better.

Adolescent↗

PubMed1998

Molecular toxicology and the medicinal chemist.

Drug metabolism has a number of pharmacodynamic and pharmacokinetic consequences which cannot be ignored even at the early stages of drug research. A number of aspects of drug metabolism are thus of interest to medicinal chemists, e.g. prodrug and soft drug design. This mini-review focuses mainly on toxication resulting from reactions of functionalization and conjugation. In the former case, oxidoreductases can reduce xenobiotics to nucleophilic radicals, or oxidize them to electrophilic and oxidizable metabolites. Conjugation reactions also play a role in toxication by generating lipophilic residues (e.g. hybrid triglycerides) or adduct-forming metabolites (e.g. some acylglucuronides), or by interfering with physiological pathways (e.g. Coenzyme A conjugates). Functional moieties undergoing such reactions are known as toxophoric groups. Because they are the biochemical endpoint of several toxication reactions, macromolecular adducts are now of special significance in molecular toxicology. But, as discussed in the conclusion, the substrate specificity of drug-metabolizing enzymes, the many biological factors that influence metabolism, and various repair and removal mechanisms all contribute to decrease toxicological risks and to protect organisms.

Biotransformation↗

PubMed1998

Cessation of gonadotropin-releasing hormone agonist therapy combined with high-dose gonadotropin stimulation yields favorable pregnancy results in low responders.

OBJECTIVE: To evaluate the pregnancy results of an ovarian hyperstimulation protocol for IVF-ET that combines GnRH agonist down-regulation, cessation of GnRH agonist therapy with the onset of menstruation, and high-dose gonadotropin administration in low responders. DESIGN: Prospective analysis. SETTING: Academic IVF program. PATIENT(S): One hundred eighty-two low responders undergoing 224 IVF-ET cycles. INTERVENTION(S): Down-regulation was obtained with the administration of leuprolide acetate beginning in the midluteal phase and ending with the onset of menses. Daily administration of 6 ampules of FSH alone or in combination with hMG was initiated on cycle day 3. MAIN OUTCOME MEASURE(S): Stimulation characteristics and pregnancy rates (PRs) were compared between fresh cycles in which pure FSH alone was used and 35 cycles in which a combination of FSH and hMG was administered. RESULT(S): The clinical PR per transfer, the ongoing PR per transfer, and the implantation rate were 32%, 24%, and 9%, respectively. No differences were noted between cycles in which pure FSH alone was used in comparison with cycles in which a combination of FSH and hMG was administered. CONCLUSION(S): Short-term ovarian suppression begun in the luteal phase and discontinued with the onset of menses followed by high-dose stimulation with gonadotropins yields favorable pregnancy results in low responders.

Adult↗

PubMed1998

Impact of fertilization history and semen parameters on ICSI outcome.

PURPOSE: The objectives of this study were (1) to investigate intracytoplasmic sperm injection (ICSI) outcome according to its indications, i.e., a history of failed or poor fertilization and unsuitable sperm parameters for conventional IVF, and (2) to examine the impact of a female's age, sperm concentration, motility, morphology, presence of antisperm antibodies, and hemizona assay (HZA) results on overall outcome. METHODS: Two hundred seventy-nine ICSI cycles performed in 207 couples were retrospectively evaluated. RESULTS: Clinical pregnancy and delivery rates were 36.8 and 29.8% for patients with prior failed fertilization, 23.2 and 17.8% for patients who had prior poor fertilization, and 28.6 and 21.3% for patients with unsuitable sperm parameters. The differences among all groups were found to be insignificant. There was a significant, negative correlation between a female's age and pregnancy results. No difference was found in the three basic sperm parameters between those patients who produced and those who did not produce a pregnancy, but the fertilization rate was significantly higher in patients with more adequate sperm parameters. Although there was a trend toward a better fertilization rate in patients with a hemizona index (HZI) greater than 30 (indicative of a superior sperm-zona pellucida binding capacity) than in those with a HZI less than 30, the difference was not significant. There were no differences in fertilization rate according to the presence or absence of antisperm antibodies. CONCLUSIONS: Fertilization history in a conventional IVF cycle has no effect on success rates following ICSI, and there is no correlation among the basic sperm parameters, the presence of antisperm antibodies, and pregnancy rates.

Age Factors↗

PubMed1998

Semen quality: is there a paternal effect on pregnancy outcome in in-vitro fertilization/intracytoplasmic sperm injection?

The objective of this study was to investigate the role of the spermatozoon (paternal effects) on implantation and pregnancy outcome in in-vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI). Male individuals of three types were analysed: infertile men with oligoasthenoteratozoospermia (OAT), infertile men with normozoospermia and fertile men (donors). Female counterparts were judged to have comparable egg quality within two groups studied, i.e. infertile women with pure mechanical (tubal) infertility and recipients of donor eggs. There were significantly higher differences in implantation and pregnancy rates in groups using donor spermatozoa and donor egg recipients. Analyses of key set groups revealed a trend toward a poorer implantation and pregnancy outcome when comparing OAT versus normozoospermic patients within IVF, but not within ICSI treatments, in couples with tubal infertility. In couples who were recipients of donor eggs, no differences were observed between OAT patients treated by ICSI and normozoospermic patients treated with IVF. No significant differences were observed in miscarriage rates within any groups studied. In conclusion, the poorer results observed in OAT patients undergoing IVF may be secondary to spermatozoal effects due to a high insemination concentration. Overall, there does not seem to be a significant effect of severe male infertility (OAT) on implantation and pregnancy outcome. However, this does not preclude that specific sperm aberrations may exert a negative effect on embryogenesis and therefore on implantation potential following assisted or in-vivo reproduction.

Adult↗

PubMed1998

Secretory phospholipase A2 in patients with infected pancreatic necroses in acute pancreatitis.

Secretory synovial-type PLA2 (sPLA2-II) in peripheral blood is known to be associated with systemic complications in patients with severe diseases. Being the pacemaking enzyme in eicosanoid synthesis, sPLA2-II is a mediator of the inflammatory response and plays a role in host defense against bacterial infection. We evaluated the clinical role of systemic sPLA2-II in bacterial infection of pancreatic necroses in severe acute pancreatitis. In 58 patients with acute pancreatitis, pancreatic and sPLA2-I and sPLA2-II were measured daily for the first 14 days of hospital treatment by a time-resolved fluoroimmunoassay. All 36 patients with necrotizing pancreatitis underwent regular fine needle aspiration (FNA) to monitor bacterial infection. In 10 patients, infected necroses were found on FNA and postoperative examination. On admission and at most days throughout the observation period, systemic sPLA2-II was significantly higher in patients with infected necroses than in patients with sterile necroses or interstitial pancreatitis. This difference was not found for sPLA2-I, but values were higher in necrotizing pancreatitis than in interstitial pancreatitis at the first 2 days of hospital treatment. If sPLA2-II was >300 ng/ml on 2 successive days within the first 4 days, infected necroses could be predicted with a sensitivity of 89%, a specificity of 88%, and a negative predictive value of 95%. Systemic sPLA2-II has the potential to identify patients at risk of bacterial infection of pancreatic necroses and its routine measurement may therefore, in combination with FNA, offer a valuable tool in monitoring patients with acute necrotizing pancreatitis.

Acute Disease↗

PubMed1998

Efficacy of polymerase chain reaction for detection of deep mycotic infections: confirmation by autopsy.

A method based on polymerase chain reaction (PCR) amplification of fungal 18S rDNA sequences was tested for the detection of fungi in blood samples. In order to increase sensitivity and specificity, PCR products were hybridized to the radioactively labelled fragment of 18S rDNA gene. Blood from 28 patients with haematological malignancies was taken immediately after death and the results of PCR analysis were compared with results of autopsy examination. To the best of our knowledge, no study of such a design has been published previously. PCR analysis turned out to be very sensitive (92%) and specific (92%) as well as capable of detecting various kinds of fungal infections (localized as well as generalized).

Adult↗

PubMed1998

Human endogenous retrovirus K homologous sequences and their coding capacity in Old World primates.

The coding capacity for retroviral Gag and Env proteins has been maintained in human endogenous retroviruses of the HERV-K family. HERV-K homologous sequences have been found in all Old World primates. Here, we examined Old World primate species for the presence of full-length HERV-K gag and env genes and the presence of gag and env open reading frames as determined by the protein truncation test. Full-length HERV-K env genes were found in DNAs of all Old World primate species, whereas open reading frames for Env protein were found solely in human, chimpanzee, and gorilla DNAs. The mutational event leading to two HERV-K types was found to have occurred after the separation of hominids from lower Old World primates and before the expansion of hominids. Full-length HERV-K gag genes in hominids displayed a 96-bp deletion compared to those in lower Old World primates. The ancient gag variant has not been maintained during hominid evolution. Open reading frames for HERV-K Gag have been found in all Old World primates except chimpanzees. Our study of the HERV-K family during Old World primate evolution contributes to the understanding of their possible biological functions in the host genomes.

Animals↗

PubMed1998

[Autologous transplantation of peripheral stem cells in treatment of recurrent multiple myeloma].

Treatment of relapses of multiple myeloma is a problem which was not resolved quite satisfactorily so far. One of the possible therapeutic approaches is administration of major doses of chemotherapeutic agents with the support of autologous transplantation. As compared with standard treatment, according to some authors thus more remissions are achieved and a longer overall survival. The submitted paper provides information on the therapeutic results in relapses of multiple myeloma by administration of large doses of melfalan (200 mg/m2) with support of autologous transplantation in seven patients in the authors department. In these patients for stimulation smaller doses of cyclophosphamide were used (2-3 g/m2) and in half of them also larger doses of leucocytic growth factor (16 micrograms/kg) than usually in newly treated patients with multiple myeloma who receive as part of the stimulating regime 5 g/m2 cyclophosphamide and 10 micrograms/kg leucocytic growth factor. The yield of peripheral stem cells was good in all these patients. Of five patients with a chemosensitive relapse of the disease the authors achieved after transplantation three remissions and two partial remissions. So far all patients survive, one in relapse, two in remission, two in partial remission. Of the two patients with a chemoresistant relapse one died on the 17th day after transplantation, the other one achieved temporary 6-month remission and then died during the second fulminant relapse of the disease. Autologous transplantation seems to be an asset in particular in patients with a chemosensitive relapse of the disease. The authors summarize hitherto known facts concerning this problem published in the literature abroad.

Adult↗

PubMed1998

[Failure conditions of glass filament yarns: a contribution to the valuation of carcinogenic potentials of fiber fragments].

Failure of glass filament yarns results in the formation of many fragments. Through inhalation, these particles can intrude into the human body. If the fragments are sufficiently bioresistant and have a fiber dust geometry, according to the MAK-values (6), i.e. if they are longer than 5 microns and thinner than 3 microns and show an aspect ratio greater than 3, they have a carcinogenic potential. Since the glass filaments show a diameter greater than 3 microns, no fiber dust particles will be formed if transversal fiber failure occurs without crack-branching. In the present study the geometric distribution of fragments after failure of glass filament yarns under combined stress was investigated in order to estimate the carcinogenic potential of the fragments. The knot tension test was shown to be a suitable method for this investigation. A defined fraction of the total amount of fragments were analysed with scanning electron microscopy (SEM) by measuring their length and diameter. To investigate whether the analysed particles are fragments of the glass filament yarns, chemical analysis was performed with energy dispersive X-ray analysis (EDX). Morphologically, two different fragment types were observed: a) Fragments with their entire filament cross-section which were formed by transversal fiber fraction. b) Smaller fragments which were formed through crack-branching. These smaller fragments were observed to adhere on the bigger fragments due to high surface forces. During each knot tension test, 5-60 fragments per filament were formed. However, the fraction of fiber dust particles was very low and showed a maximum of 1.5%. Only in one of the four tested yarn types (high temperature yarn HT 75) the formation of fiber dust particles was observed. The other yarns showed fragments with dimensions close to fiber dust geometry. Therefore, it cannot be excluded that some fragments with fiber dust geometry may have been formed during mechanical testing. Fragment distribution of the studied E-glass yarns was shown to be dependent on the modification method. To date, it cannot be excluded that there are types of glass filament yarns forming a major quantity of fiber dust particles during failure. The fragments of type b such as fiber dust particles were observed to adhere on bigger fragments which are themselves too big to reach the alveoli. In the present study the stability of these agglomerates under various environmental conditions was not investigated. Moreover, fragment agglomerates should not be considered on their own but in connection with the application. The presented tests were carried out with simple yarns and, therefore, represent isolated observations.

Air Pollutants↗

PubMed1998

Surgical treatment of acute pancreatitis.

The most important diagnostic step in the management of patients with severe acute pancreatitis is discrimination between interstitial-oedematous and necrotizing pancreatitis. Surgical decision-making is based on clinical, bacteriological and contrast-enhanced CT-data. Persisting or progressive systemic or local organ complications occurring despite ICU-treatment are indicators for surgical management. Patients suffering from sepsis syndrome, cardiovascular shock, multisystemic organ failure syndrome, surgical acute abdomen and persisting or progressing ileus should be treated surgically. The surgical technique is based on careful necrosectomy or debridement in combination with continuous or repeated surgical evacuation of necrotic tissue, bacteria and biologically active compounds. Necrosectomy and postoperative continuous local lavage resulted in a hospital mortality of 17% in necrotizing pancreatitis, conservative management of necrotizing pancreatitis in a hospital mortality of 6.3%. In 1442 patients treated in a 14-year period the overall hospital mortality was 4.4%.

Acute Disease↗

PubMed1997

Systematic review of the diagnostic accuracy of dermatoscopy in detecting malignant melanoma.

OBJECTIVE: To assess the evidence that dermatoscopy improves the accuracy of diagnosis of melanomas in clinical practice. DATA SOURCES: MEDLINE 1983-January 1997, EMBASE 1980-1996, and bibliographies of retrieved articles. STUDY SELECTION AND DATA EXTRACTION: Studies selected were original studies with formal methods and results sections comparing diagnostic accuracy of dermatoscopy for malignant melanoma with another clinical method; the criterion standard was excision biopsy with histopathological examination; and accuracy of dermatoscopic diagnosis was determined over a spectrum of stages of melanoma and skin lesions commonly confused with melanoma. Data were extracted by a single observer. DATA SYNTHESIS: 579 articles were identified; six studies met the inclusion criteria. Positive likelihood ratios for dermatoscopy for diagnosis of melanoma ranged from 2.9 to 10.3. Dermatoscopy had 10%-27% higher sensitivity than clinical diagnosis in the two studies with the most clinically equivocal lesions. However, when sensitivity of clinical diagnosis was more than 84%, sensitivity of dermatoscopy was only slightly higher. One study of dermatologists with no training in dermatoscopy showed a significant decrease in sensitivity. CONCLUSIONS: Variability between studies in methods, observers and types of pigmented skin lesions and lack of studies in primary care make generalisation of results difficult. Dermatoscopy appeared not to improve the accuracy of diagnosis enough to alter the clinical management of most pigmented skin lesions. Further research with more explicit methods is needed.

Humans↗

PubMed1997

Natural course of acute pancreatitis.

Acute pancreatitis comprises, in terms of clinical, pathologic, biochemical, and bacteriologic data, four entities. Interstitial edematous pancreatitis and necrotizing pancreatitis are the most frequent clinical manifestations; pancreatic pseudocyst and pancreatic abscess are late complications after necrotizing pancreatitis, developing after 3 to 5 weeks. Determinants of the natural course of acute pancreatitis are pancreatic parenchymal necrosis, extrapancreatic retroperitoneal fatty tissue necrosis, biologically active compounds in pancreatic ascites, and infection of necrosis. Early in the course of acute pancreatitis multiple organ failure is the consequence of various inflammatory mediators that are released from the inflammatory process and from activated leukocytes attracted by pancreatic injury. During the late course, starting the second week, local and systemic septic complications are dominant. Around 80% of deaths in acute pancreatitis are caused by septic complications. The infection of pancreatic necrosis occurs in 8% to 12% of acute pancreatitis and in 30% to 40% of patients with necrotizing pancreatitis. Bacteriologic analysis of intraoperative smears and aspirates reveals predominantly gram-negative germs deriving from the intestine, most frequently Escherichia coli. It has been confirmed that after necrotizing pancreatitis a considerable large group of patients suffer long-lasting exocrine and endocrine insufficiency.

Abscess↗

PubMed1997

Surface activation of polyetheretherketone (PEEK) and formation of calcium phosphate coatings by precipitation.

Plasma activation of polyetheretherketone (PEEK) surfaces and the influence on coating formation in a supersaturated calcium phosphate solution was investigated in this study. It was observed that plasma treatment in a N2/O2 plasma had a significant effect on the wettability of the PEEK surface. The contact angle decreased from 85 degrees to 25 degrees after plasma treatment. Cell culture testing with osteoblastic cell lines showed plasma activation not to be disadvantageous to cell viability. X-ray photoelectron spectroscopy (XPS) analysis was performed to characterize the chemical composition of the PEEK surfaces. It was observed that the O1s intensity increased with plasma activation time. At the C1s peak the appearance of a shoulder at higher binding energies was observed. Coating of PEEK was performed in a supersaturated calcium phosphate solution. Coating thicknesses of up to 50 microm were achieved after 24 days of immersion. Plasma activation followed by nucleation in a highly saturated hydroxyapatite solution had a positive effect on the growth rate of the layer on PEEK. Chemical analysis revealed that the coating consists of a carbonate-containing calcium phosphate.

Journal Article↗

PubMed1997

Topographical characterization and microstructural interface analysis of vacuum-plasma-sprayed titanium and hydroxyapatite coatings on carbon fibre-reinforced poly(etheretherketone).

In the present study, topographical characterization and microstructural interface analysis of vacuum-plasma-sprayed titanium and hydroxyapatite (HA) coatings on carbon fibre-reinforced polyetheretherketone (CF/PEEK) was performed. VPS-Ti coatings with high roughness values (Ra=28.29+/-3.07 microm, Rz=145.35+/-9.88 microm) were obtained. On this titanium, intermediate layer HA coatings of various thicknesses were produced. With increasing coating thickness, roughness values of the HA coatings decreased. A high increase of profile length ratio, Lr, of the VPS-Ti coatings (Lr=1.45) compared to the grit-blasted CF/PEEK substrate (Lr=1.08) was observed. Increasing the HA coating thickness resulted in a reduction of the Lr values similar to the roughness values. Fractal analysis of the obtained roughness profiles revealed that the VPS-Ti coatings showed the highest fractal dimension of D=1.34+/-0.02. Fractal dimension dropped to a value of 1.23-1.25 for all HA coatings. No physical deterioration of the CF/PEEK substrate was observed, indicating that substrate drying and the used VPS process parameter led to the desired coatings on the composite material. Cross-section analysis revealed a good interlocking between the titanium intermediate layer and the PEEK substrate. It is therefore assumed that this interlocking results in suitable mechanical adhesive strength. From the results obtained in this study it is concluded that VPS is a suitable method for manufacturing HA coatings on carbon fibre-reinforced PEEK implant materials.

Journal Article↗

PubMed1997

Colonoscopic allergen provocation (COLAP): a new diagnostic approach for gastrointestinal food allergy.

BACKGROUND: The clinical relevance of gastrointestinal food allergy in adults is largely unknown because the mechanisms are poorly understood and the diagnosis is difficult to confirm. AIMS: To improve the diagnostic means for confirming intestinal food allergy on an objective basis, a new colonoscopic allergen provocation (COLAP) test was developed. PATIENTS: The COLAP test was performed in 70 adult patients with abdominal symptoms suspected to be related to food allergy, and in five healthy volunteers. METHODS: During the COLAP test, the caecal mucosa was challenged endoscopically with three food antigen extracts, a buffer control, and a positive control (histamine). The mucosal weal and flare reaction was registered semiquantitatively 20 minutes after challenge, and tissue biopsy specimens were examined for mast cell and eosinophil activation. RESULTS: No severe systemic anaphylactic reactions were found in response to intestinal challenge. The COLAP test was positive to at least one food antigen in 54 of 70 patients (77%), whereas no reaction in response to antigen was found in healthy volunteers. Antigen induced weal and flare reactions were correlated with intestinal mast cell and eosinophil activation, as well as with patients' history of adverse reactions to food, but not with serum concentrations of total or specific IgE or skin test results. CONCLUSION: The COLAP test may be a useful diagnostic measure in patients with suspected intestinal food allergy and may provide a new tool for the study of underlying mechanisms.

Adolescent↗

PubMed1997

Multiple human endogenous retrovirus (HERV-K) loci with gag open reading frames in the human genome.

Human endogenous retrovirus HERV-K is present in 25-30 copies per haploid human genome. At least one of these loci is capable of producing full-length Gag protein, high amounts of which have been detected in germ cell tumors and derived cell lines. The latter display HERV-K Gag-encoded retroviral particles. Here, we employed the protein truncation test (PTT) in combination with a monochromosomal hybrid mapping panel to identify the human chromosomes harboring HERV-K gag genes with an open reading frame for Gag protein. Eight human chromosomes were found to contain intact HERV-K gag genes. PTT results were corroborated by partial sequencing of subregions from different HERV-K gag genes. The high number of HERV-K Gag open reading frames supports the idea of retroviral sequences retaining a biological benefit in the human genome.

Animals↗