Biomedical subjects

C Y Liu

Publications and source records attributed to C Y Liu.

At least 73 records · Page 4Linked to original sources

PubMed2000

Analysis of sharp-edged medical-object injuries at a medical center in Taiwan.

A total of 733 incidents by sharp-edged objects occurred among healthcare workers between 1995 and 1998. Injuries occurred most frequently among interns. The workplace location with the highest incidence of injury was the patient ward, and the object that most frequently inflicted injury was a needle. The most frequent work practice was recapping of syringes. One healthcare worker demonstrated seroconversion for hepatitis C.

Hepatitis C↗

PubMed2000

Antimicrobial resistance of Streptococcus pneumoniae isolated in Taiwan: an island-wide surveillance study between 1996 and 1997.

Between August 1996 and July 1997, 550 clinically significant Streptococcus pneumoniae isolates were collected from 14 geographically separate laboratories in Taiwan. These isolates were serotyped and MICs were determined by agar dilution. Among serotypes covered by the 23-valent vaccine, types 19F, 19A, 23F, 23A and 6B dominated, comprising 255 isolates; among non-vaccine serotypes, types 35, 39, 34, 13 and 31 dominated, comprising 118 isolates. Of the 550 isolates, 310 (56.4%) were resistant to penicillin G (MIC 0. 12 mg/L), 238 (43.3%) with intermediate resistance (MIC 0.12-1 mg/L) and 72 (13.1%) with high-level resistance (MIC 2 mg/L). Most non-susceptible pneumococci were of serotypes 19F and 23F; non-susceptible isolates of these serotypes were distributed across all of Taiwan. Fourteen other antibiotics were tested; 83% of the isolates were resistant to tetracycline, 78% to azithromycin, 74% to erythromycin, 54% to clindamycin and 23% to chloramphenicol. Thus, macrolides can no longer be used as first line agents to treat pneumococcal infections in Taiwan. Multi-resistance (isolates resistant to three or more chemically unrelated antibiotics) was found in each serotype or group, but mostly in types 19F and 23F. The emergence of such strains complicates antibiotic selection, but both types are covered by the 23-valent vaccine, as were 82% of the isolates from blood and eight of the nine from cerebrospinal fluid. Good antibiotic control and appropriate use of this vaccine may improve the current problem in Taiwan, especially for the elderly.

Adolescent↗

PubMed2000

Subjective memory complaint in relation to cognitive performance and depression: a longitudinal study of a rural Chinese population.

OBJECTIVES: To examine the associations of subjective memory complaint (SMC) in old age with (a) objective test performance, (b) past and subsequent cognitive decline, and (c) depression. DESIGN: A group of community residents were examined twice during a 3-year period. SETTING: Two townships on a rural Chinese islet. PARTICIPANTS: A total of 543 men and women aged 65 years and older. MEASUREMENTS: During each examination, neurologists interviewed and examined all participants for dementia and asked the question, "Do you have trouble with your memory?" In addition, research assistants administered (a) the Cognitive Abilities Screening Instrument (CASI) to assess cognitive abilities, including long-term memory (LTM) and short-term memory (STM), and (b) the Geriatric Depression Scale-Short Version (GDS-S) to assess symptoms of depression. RESULTS: At each examination, almost half of the subjects acknowledged having trouble with their memory (the SMC+ group). At both examinations, the SMC+ group scored significantly lower on the CASI and significantly higher on the GDS-S than the SMC- group. However, the presence of SMC was not associated with faster cognitive decline over the past or subsequent 3 years. There were no consistent associations between SMC and the demographic variables of age, gender, and education at the two examinations. Logistic regression analysis showed that SMC was associated with poorer memory test scores after controlling for gender, age, education, and depression. CONCLUSIONS: SMC was associated with poorer objective memory performance even after controlling the effect of depression and demographic data, but SMC did not predict faster cognitive decline or dementia over 3 years.

Aged↗

PubMed2000

Intra- and extracellular measurement of reactive oxygen species produced during heat stress in diaphragm muscle.

Skeletal muscles are exposed to increased temperatures during intense exercise, particularly in high environmental temperatures. We hypothesized that heat may directly stimulate the reactive oxygen species (ROS) formation in diaphragm (one kind of skeletal muscle) and thus potentially play a role in contractile and metabolic activity. Laser scan confocal microscopy was used to study the conversion of hydroethidine (a probe for intracellular ROS) to ethidium (ET) in mouse diaphragm. During a 30-min period, heat (42 degrees C) increased ET fluorescence by 24 +/- 4%, whereas in control (37 degrees C), fluorescence decreased by 8 +/- 1% compared with baseline (P < 0.001). The superoxide scavenger Tiron (10 mM) abolished the rise in intracellular fluorescence, whereas extracellular superoxide dismutase (SOD; 5,000 U/ml) had no significant effect. Reduction of oxidized cytochrome c was used to detect extracellular ROS in rat diaphragm. After 45 min, 53 +/- 7 nmol cytochrome c. g dry wt(-1). ml(-1) were reduced in heat compared with 22 +/- 13 nmol. g(-1). ml(-1) in controls (P < 0.001). SOD decreased cytochrome c reduction in heat to control levels. The results suggest that heat stress stimulates intracellular and extracellular superoxide production, which may contribute to the physiological responses to severe exercise or the pathology of heat shock.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗

PubMed2000

Using conjunctival swab with polymerase chain reaction to aid diagnosis of cytomegalovirus retinitis in AIDS patients.

Conjunctival swabs were used in combination with polymerase chain reactions (PCR) or virus culture to aid to confirm the diagnosis of cytomegalovirus (CMV) retinitis in AIDS patients. Based on ophthalmoscopic findings, 13 AIDS patients were diagnosed as having CMV retinitis and treated with systemic ganciclovir from January 1997 to December 1998. Nine of 13 AIDS patients with CMV retinitis were found to be positive for CMV DNA by using a conjunctival swab with PCR (CS-PCR). CMV was also isolated from the conjunctival swab culture in 2 AIDS patients with CMV retinitis. Following 1 month of systemic ganciclovir treatment, except for 1 patient who had disease progression and remained positive for CMV DNA by using CS-PCR, 12 patients were negative for CMV with a concordant lesion regression. Results of this study also indicate that this CS-PCR method is valuable for confirming the diagnosis of CMV retinitis and monitoring the ganciclovir effect on the treatment of CMV retinitis in AIDS patients.

AIDS-Related Opportunistic Infections↗

PubMed2000

Nitric oxide modulates interleukin-1beta and tumor necrosis factor-alpha synthesis by alveolar macrophages in pulmonary tuberculosis.

Interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha released from alveolar macrophages (AM) in pulmonary tuberculosis (TB) are important in host defense against mycobacterial infection. Nitric oxide (NO) production is enhanced in AM of TB patients. We examined whether NO was implicated in (IL)-1beta and TNF-alpha synthesis by AM of TB patients. Purified AM were retrieved by bronchoalveolar lavage from 11 TB patients and 10 normal subjects, and were cultured with or without the NO inhibitor N(G)-monomethyl-L-arginine (L-NMMA). The release of IL-1beta and TNF-alpha, and expression of their messenger RNAs (mRNAs), were determined by enzyme-linked immunosorbent assay and Northern blot analysis. The release of IL-1beta and TNF-alpha was greater from AM of TB patients than from AM of normal subjects. L-NMMA inhibited nitrite, IL-1beta, and TNF-alpha production in TB patients. The mRNA expression for IL-1beta and TNF-alpha was upregulated in TB patients and was depressed by L-NMMA. Immunocytochemistry done with a monoclonal antibody against the p65 subunit of nuclear factor (NF)-kappaB showed that NF-kappaB was highly expressed and translocated to the nuclei of AM from TB patients, and was inhibited by L-NMMA. Inhibition of NF-kappaB by pyrrolidine dithiocarbamate attenuated IL-1beta and TNF-alpha synthesis. In conclusion, enhanced NO generation by AM of TB patients plays an autoregulatory role in amplifying the synthesis of proinflammatory cytokines, probably through NF-kappaB activation.

Adult↗

PubMed2000

Detection of human cytomegalovirus retinitis and monitoring of ganciclovir treatment using conjunctival swab with polymerase chain reaction in AIDS patients.

This report studies the accuracy of conjunctival swab polymerase chain reaction (CS-PCR) for the diagnosis of human cytomegalovirus retinitis (HCMV) in AIDS patients. PCR and virus culture were used for the detection of HCMV in conjunctival swab, serum, and urine specimens from 38 AIDS patients between April 1996 and April 1998. The clinical utility of the identification of HCMV retinitis by these 6 different methods was demonstrated by their prediction power to estimate AIDS patients at risk of contracting HCMV retinitis. The sensitivity, specificity, positive predictive value, and negative predictive value of CS-PCR for the detection of HCMV retinitis were 91.5%, 80.9%, 60.8%, and 92.7%, respectively; for serum PCR were 74.3%, 81.7%, 57.2%, and 90.3%; for urine PCR were 100%, 17.3%, 20.4%, and 100%; for conjunctival swab culture were 22.7%, 100%, 100%, and 86%; for serum culture were 27.3%, 98.1%, 75%, and 86.4%; and for urine culture were 90.9%, 44.2%, 25.6%, and 95.8%.

AIDS-Related Opportunistic Infections↗

PubMed2000

In vitro activity of quinupristin/dalfopristin and other antibiotics against ampicillin-resistant enterococcus faecium.

BACKGROUND: Enterococcus faecium constitutes approximately 10% of clinical isolates of enterococci and is noted for its antimicrobial resistance. In particular, E faecium is commonly resistant to ampicillin. The optimal treatment for severe infections caused by these multi-resistant organisms has yet to be determined. METHODS: Enterococci tested were isolated from blood, pleural fluid and cerebrospinal fluid. Ampicillin-resistant Enterococcus faecium (AREF) was identified using the API Rapid Strep Kit system. A total of 58 isolates of AREF were enrolled in this study. Ten different antibiotics were tested, including Synercid (quinupristin/dalfopristin), teicoplanin, vancomycin, ampicillin, trimethoprim/sulfamethoxazole (TMP/SMX), ciprofloxacin, gentamicin, chloramphenicol, rifampicin and tetracycline. The agar dilution method described by the National Committee for Clinical Laboratory Standards was used to determine the minimum inhibitory concentrations (MICs) of the antibiotics tested. RESULTS: Teicoplanin showed the best in vitro activity. Its MIC ranged from 0.25 to 2 micrograms/ml with an MIC90 of 1 microgram/ml. The MIC of vancomycin was 0.5-128 micrograms/ml with an MIC90 of 2 micrograms/ml. Three strains were vancomycin resistant, and they were the VanB phenotype. The MIC of quinupristin/dalfopristin was 0.5 to 8 micrograms/ml with an MIC90 of 2 micrograms/ml. Chloramphenicol and tetracycline showed moderate susceptibility. AREF showed high resistance to other antibiotics tested, including ciprofloxacin, gentamicin, TMP/SMX and rifampicin. High-level gentamicin resistance (MIC > 1,000 micrograms/ml) was found in 78% of AREF tested. CONCLUSIONS: Teicoplanin showed the best in vitro activity against AREF. Clinical studies are necessary to confirm the efficacy of quinupristin/dalfopristin in vivo.

Ampicillin Resistance↗

PubMed2000

TT virus infection among hemodialysis patients at a medical center in Taiwan.

Although the association between TT virus (TTV) infection and hepatitis is controversial, the high prevalence of TTV infection in healthy blood donors and even higher rate among frequently transfused patients poses a potential threat to public health and clinical care. In addition, there is a lack of data concerning the prevalence and mode of transmission of TTV infection in different subpopulations in Taiwan. In the present study, we investigated the prevalence of TTV infection in 111 uremic patients receiving regular hemodialysis in a single hospital in Taiwan. Blood samples were collected and analyzed using a seminested polymerase chain reaction (PCR) designed to amplify a 271 base-pair DNA fragment. The results show that the overall TTV positive rate in uremic patients in our hospital was 61% (68/111), which was much higher than the reported TTV prevalence rate among the normal population (ranging from 1%-12%). The results of analysis of the demographic and clinical characteristics of the patients indicate that blood transfusion may play an important role in TTV transmission (p < 0.05). In addition, the hepatitis B positive rate was significantly lower in TTV positive patients. However, liver function tests were not significantly different between TTV positive and TTV negative patients. The results of the present study suggest that blood transfusion plays an important role in TTV transmission in uremic patients.

Adult↗

PubMed2000

Ophthalmic findings in patients with acquired immunodeficiency syndrome.

Ocular manifestations have been reported in up to 60% of individuals infected with human immunodeficiency virus (HIV) in the United States, and it is becoming increasing apparent that these ocular manifestations almost invariably reflect extent of progression of the disease. The prevalence of ocular abnormalities among acquired immunodeficiency syndrome (AIDS) patients in Taiwan has not been reported. In the present study, we examined and followed up the ophthalmic conditions of a total of 274 HIV-infected patients during the period from March 1993 to May 1999. The results show that cotton-wool spots was the most common ocular finding in this series of patients with AIDS, occurring in 22 (32.8%) of 67 AIDS patients. Cytomegalovirus (CMV) retinitis was the most commonly seen opportunistic ocular infection, occurring in 14 (20.8%) of 67 AIDS patients. These findings suggest that AIDS patients should be closely followed for signs of opportunistic ocular disease which may initially be asymptomatic. Close co-operation between the ophthalmologist and the internist is essential to ensure timely therapeutic intervention, which can decrease the risk of further complications including visual impairment and blindness.

Acquired Immunodeficiency Syndrome↗

PubMed2000

Meropenem versus imipenem/cilastatin in the treatment of sepsis in Chinese patients.

BACKGROUND: Meropenem and imipenem are beta-lactam antibiotics of the carbapenem group. Carbapenems have bactericidal activity against a broad spectrum of bacteria, including most gram-positive cocci, gram-negative bacilli and anaerobes. Experience in using meropenem in Chinese patients has not been previously reported. METHODS: Meropenem (2 g daily) and imipenem/cilastatin (2 g daily) were compared in an open, randomized, prospective study on the treatment of hospitalized Chinese septic patients. All participants (male or female) were hospitalized with a diagnosis of sepsis. All patients were randomly allocated to one of the two treatment groups: the meropenem group or the imipenem/cilastatin group. Clinical status was evaluated daily during treatment and at the end of therapy or when treatment was withdrawn. Patients were checked every day for potential side-effects, according to subjective and objective symptoms. RESULTS: Fifty-three patients were enrolled in the study; 50 were evaluated for clinical efficacy and 27 patients were evaluated for bacteriologic efficacy. The most frequent clinical diagnoses were pneumonia and urinary tract infection. The predominant pathogens were Pseudomonas aeruginosa, Escherichia coli and Enterobacter cloacae. There were 31 pathogens isolated from 27 patients. A single pathogen was identified in 23 patients, and two pathogens were isolated from four patients. Satisfactory clinical outcome (excellent and good) was 84% in the meropenem group and 76% in the imipenem/cilastatin group. Satisfactory bacteriologic response was 80% in the meropenem group and 75% in the imipenem/cilastatin group. Transiently elevated liver enzymes were the most common side-effect. One patient treated with imipenem/cilastatin experienced a seizure during the study, while another patient treated with meropenem withdrew due to urticaria. CONCLUSIONS: The efficacy and safety data presented in this report indicate that meropenem was well tolerated and appeared to be as effective as standard monotherapy with imipenem in bacteremic patients. Meropenem and imipenem/cilastatin were highly effective for the treatment of bacteremia in Chinese patients and only mild or negligible side-effects were noted.

Adult↗

PubMed2000

In vitro activity of quinupristin/dalfopristin against gram-positive bacteria Haemophilus influenzae and Branhamella catarrhalis in Taiwan.

BACKGROUND: Over the past decade, resistance of Gram-positive cocci to common antibiotics has steadily increased. New antibacterial agents that are active against multidrug-resistant pathogens are urgently needed for the treatment of these pathogens. We conducted an in vitro study on the activity of quinupristin/dalfopristin and other antibiotics against common clinical isolates of the gram-positive cocci, Haemophilus influenzae and Branhamella catarrhalis. METHODS: The agar dilution method described by the National Committee for Clinical Laboratory Standards was used to determine the minimum inhibitory concentrations (MICs) of bacterial isolates from clinical specimens obtained from patients in a medical center. RESULTS: All Staphylococcus aureus isolates were inhibited by quinupristin/dalfopristin (< or = 2 micrograms/ml). The MIC90s were 1 mg/ml for both methicillin-sensitive and -resistant S aureus. Quinupristin/dalfopristin inhibited streptococci at a concentration of 1 microgram/ml or less. The MIC90s were 1 microgram/ml for Streptococcus pneumoniae, S pyogenes and viridans streptococci. Ampicillin-resistant Enterococcus faecium was inhibited by quinupristin/dalfopristin at 0.5 to 4 micrograms/ml, with an MIC90 of 1 microgram/ml. H influenzae was inhibited by quinupristin/dalfopristin at 0.25 to 8 micrograms/ml, with an MIC90 of 4 micrograms/ml. B catarrhalis was inhibited by quinupristin/dalfopristin at 0.25 to 1 microgram/ml, with an MIC90 of 1 microgram/ml. CONCLUSIONS: We found that quinupristin/dalfopristin showed good in vitro activity against staphylococci, streptococci and B catarrhalis but less in vitro activity against H influenzae.

Anti-Bacterial Agents↗

PubMed2000

Klebsiella pneumoniae renal abscess.

BACKGROUND: The clinical characteristics of renal abscess caused by Klebsiella pneumoniae have not been previously reported in case-series studies. The purpose of this study is to demonstrate the clinical characteristics of K pneumoniae renal abscess for early diagnosis and to identify the clinical risk factors associating with poor prognosis. METHODS: We retrospectively reviewed the medical records of 24 patients with K pneumoniae renal abscess, from April, 1982 through February, 1998. The clinical presentations, including the demographic characteristics, predisposing disorders, initial signs and symptoms, laboratory test results, diagnostic radiology studies, therapeutic modalities and risk factors associated with mortality were studied. RESULTS: The mean age was 58.7 years and the male to female ratio was 10:14. The most common predisposing factors were diabetes mellitus (58%), urolithiasis (25%) and immunosuppression (17%). Fever, chills and flank pain were the most common symptoms and signs, whereas pyuria, elevation of leukocyte count, glucose, blood urea nitrogen and creatinine were the common laboratory features. The distinct complications of K pneumoniae renal abscess were bacteremia in 13 (54%), emphysematous pyelonephritis in five (21%), and metastatic septic infection in three (12.5%). The cure rate was 52% (11/21) in patients treated with a combination of antibiotics and percutaneous drainage; however, six (35%) patients who survived required another surgical procedure for complete recovery. The overall mortality rate was 25%. The clinical factors of elderly age (>65 years) at presentation, lethargy, elevation of serum blood urea nitrogen and pulmonary complications were associated with poor prognoses. CONCLUSIONS: Focusing on the early diagnosis of K pneumoniae renal abscess and recognition of the prognostic factors for a poor prognosis, we highlight the specific clinical characteristics that include elderly age, lethargy, impairment of renal function, metastatic septic lesions and pulmonary complications. All patients with K pneumoniae renal abscesses should receive empiric antibiotics and percutaneous drainage or aspiration, and surgical intervention as necessary for patients with intractable disease.

Abscess↗

PubMed2000

[The vagus nerve coordinates the motion of gallbladder and sphincter of Oddi in the interdigestive period in rabbits].

AIM: To investigate the effect of vagus nerve on coordinating the motion of gallbladder (GB) and sphincter of Oddi (SO) in the interdigestive period in rabbits. METHODS: Fasted for 15 h-18 h, but allowed to drink water, the rabbib were anesthetized with urethane (1.0 mg/kg, i.v.). In order to measure GB pressure, a frog bladder filled with normal saline was put into GB and connected to a transducer (TP-200T). Myoelectric signals of SO was recorded by a pair of copper electrodes. RESULTS: In the interdigestive period, phasic contractions of GB (PCGB) and clusters of spike potentials of SO (CSPSO) was 1:1 correlated (Y = 0.962X + 0.587, r = 0.982, P < 0.01). That is, every PCGB was accompanied by one CSPSO. Microinjection of thyrotropin-releasing hormone (TRH, 0.8 nmol, 1 microliter) or monosodium glutamate (MSG, 2 mumol, 1 microliter) into dorsal vagal complex (DVC) enhanced the motility of GB and SO, and the 1:1 temporal relation between PCGB and CSPSO still existed. Vagotomy or intravenous injection of atropine inhibited the PCGB and the spike potentials of SO, and the 1:1 correlation between PCGB and CSPSO disappeared. The spike bursts of SO did not respond to the artificial rise of gallbladder pressure. CONCLUSION: In the interdigestive period in rabbits, gallbladder and SO contract and relax rhythmically and simultaneously. This eoordinated motion between GB and SO is controlled by DVC via vagus nerve and peripheral M receptors.

Animals↗

PubMed2000

Using buffy coat for reverse transcriptase-polymerase chain reaction in the diagnosis of dengue virus infection: preliminary study.

Using reverse transcriptase-polymerase chain reaction (RT-PCR) to detect and type from viremic human serum samples for dengue virus infection is widely used today. However, a few false-negative results were reported due to very low titers of the virus particle in serum samples. As mononuclear cells, macrophages or monocytes are target cells for dengue virus infection, and the replication of virions can be observed in peripheral leukocytes frequently, the amount of virus particle in buffy coat should be higher than those in serum samples. Here, we describe a procedure in which RNA extraction from the buffy coat of a patient with a false-negative serum sample yielded specific viral RNA amplifiable by RT-PCR, thereby providing an alternative choice for the accurate diagnosis of dengue infection.

Dengue↗

PubMed2000

An Update on Laparoscopic Hysterectomy and Pelvic Floor Reconstruction.

Laparoscopic hysterectomy and pelvic floor reconstruction have recently undergone some degree of evolution. New instrumentation has appeared, such as the vaginal delineator, but overall most of the instruments used have remained basically unchanged. This is related mostly to the need of keeping costs down by limiting the use of disposable instrumentation. For pelvic reconstruction, the laparoscopic approach is now usually considered the optimal approach, as it allows the surgeon to visualize structures that the vaginal surgeon could in the past only palpate.

Journal Article↗

PubMed1999

Synthesis and analytical properties of a novel columnar metallomesogenic polymer.

A metallomesogenic side-chain polymer with copper carboxylato discotic units in stacks prepared by covalent bonding of 14-pentadecenoic acid, stearic acid and poly(methylhydrosiloxane) is described. The physico-chemical and thermal properties of both monomeric and polymeric metallomesogens were determined by elemental analysis, IR, polarizing optical microscopy, thermal gravimetric analysis and differential scanning calorimetry. The polymeric states showed a discotic lamellar phase at 50-95 degrees C and an ordered discotic hexagonal phase at 95-200 degrees C. By dynamic coating, the metallomesogenic polymer was crosslinked to the capillary wall via benzoyl peroxide. The wall-coated capillary columns (15 m x 0.25 mm I.D.) were used for the separation of phenols. Factors affecting the retention and the sample selectivity were examined. Van 't Hoff plots as a function of temperature indicated that phase transitions were occurring. Thermodynamic properties of the analytes in this system were also studied. For the determination of a mixture of 3-aminophenol, 2-chlorophenol, 2-nitrophenol, 4-nitrophenol, o-methylphenol, m-methylphenol, p-methylphenol, 2,4-dichlorophenol, 2,4-dimethylphenol, 2,4-dinitrophenol, 2,4,6-trichlorophenol, 2,4,6-trimethylphenol, 4-bromophenol, 3-methyl-4-chlorophenol, pentachlorophenol, and unsubstituted phenol, the calibration graphs for most phenols were linear over the range of 10-1000 microg ml(-1) and the mass detection limits were in the ng range based on three times standard deviation of seven measurements of the lowest peak that could be detected.

Calorimetry, Differential Scanning↗

PubMed1999

Complete nucleotide sequence of pig (Sus scrofa) mitochondrial genome and dating evolutionary divergence within Artiodactyla.

The complete nucleotide sequence of the pig (Sus scrofa) mitochondrial genome, containing 16613bp, is presented in this report. The genome is not a specific length because of the presence of the variable numbers of tandem repeats, 5'-CGTGCGTACA in the displacement loop (D-loop). Genes responsible for 12S and 16S rRNAs, 22 tRNAs, and 13 protein-coding regions are found. The genome carries very few intergenic nucleotides with several instances of overlap between protein-coding or tRNA genes, except in the D-loop region. For evaluating the possible evolutionary relationships between Artiodactyla and Cetacea, the nucleotide substitutions and amino acid sequences of 13 protein-coding genes were aligned by pairwise comparisons of the pig, cow, and fin whale. By comparing these sequences, we suggest that there is a closer relationship between the pig and cow than that between either of these species and fin whale. In addition, the accumulation of transversions and gaps in pig 12S and 16S rRNA genes was compared with that in other eutherian species, including cow, fin whale, human, horse, and harbor seal. The results also reveal a close phylogenetic relationship between pig and cow, as compared to fin whale and others. Thus, according to the sequence differences of mitochondrial rRNA genes in eutherian species, the evolutionary separation of pig and cow occurred about 53-60 million years ago.

Amino Acids↗