Search PubMed⌕ Search

Biomedical subjects

J Jenkins

Publications and source records attributed to J Jenkins.

At least 127 records · Page 7Linked to original sources
PubMed1991

Evaluation of paediatric intensive care in a regional centre.

All 162 consecutive admissions to a multidisciplinary paediatric intensive care unit in the UK have been prospectively evaluated in terms of therapeutic intention, sickness levels, age, utilisation of resources, and outcome. For 101 (62.3%) of the children admitted the aim of treatment was to cure the condition but for 30 (18.5%) ultimately only a palliative option was available. Five children were admitted to avail of specialised monitoring facilities. One half of the children admitted were physiologically unstable. The majority (102, 62.9%) were age 12 months or less. Resource utilisation, which was not affected by therapeutic intention, was greatest for the sickest patients, those age 1 month or less and non-survivors. Mortality rate overall was 17.9%. Mortality was unaffected by age and therapeutic intention and was inversely related to level of sickness. The information provided by this study forms a basis for medical audit within the unit and is essential for meaningful comparisons of standards of care and outcome with other units.

Adolescent↗
PubMed1991

Ascorbic acid concentration in amniotic fluid in late pregnancy.

Amniotic fluid and venous blood specimens were obtained from 34 pregnant women and analyzed for the ascorbic acid concentration. The mean amniotic ascorbic acid concentration of smoking pregnant women was less than 50% of that of non-smoking women. Pregnant women who smoked had a significantly lower serum and amniotic fluid ascorbic acid concentration than those who did not smoke. No differences were observed between the groups with or without premature rupture of the fetal membrane. The results suggest that ascorbic acid in the amniotic fluid reflects the ascorbic acid status in the blood of pregnant women and smoking had a greater effect in decreasing the ascorbic acid concentration in amniotic fluid than in serum.

Adult↗
PubMed1991

Open laparoscopy for laparoscopic cholecystectomy.

This report deals with the first 350 laparoscopic cholecystectomies performed at Creighton University, beginning in October 1989, by one of the authors (R.J.F., Jr.). An open technique was used for initial access to the abdominal cavity in 343 patients (98%). Patients included 274 females and 76 males, with an average age of 45.5 years. Weight ranged from 72 to 316 pounds (32-142.2 kg). The laparoscopic procedure was successfully completed in 338 (96.6%). Operative cholangiography was performed in 113 (32.3%), and 52 (14.7%) had acute cholecystitis as determined by the final pathological report. Median operating time was 80 min. There was no operative mortality. Bile duct injury was not seen. Postoperative complications occurred in 21 patients (6%), only two of which were directly related to the open technique (cellulitis of the umbilical wound requiring antibiotics). A third patient (0.3% of 343 successful laparoscopies) required reoperation on postoperative day 4 for a small bowel perforation; the exact cause could not be determined, but conceivably it was related to the umbilical minilaparotomy. We conclude that the open technique is safe and effective method for initial peritoneal access prior to laparoscopic cholecystectomy.

Adolescent↗
PubMed1991

A human tumour-derived mutant p53 protein induces a p34cdc2 reversible growth arrest in fission yeast.

We have expressed wild-type and human tumour-derived mutant p53 cDNA genes in the fission yeast Schizosaccharomyces pombe. In the case of one mutant this resulted in a growth arrest of recipient yeast cells. In contrast, wild-type p53 and three other mutant proteins tested did not block outgrowth of colonies. Human and yeast cdc2 acted as functionally equivalent extragenic suppressors of the mutant-induced growth arrest allowing the establishment of viable p53 expressor strains. In cotransformation assays the mutant allele was found to be dominant over wt p53. Our results provide the first evidence of a functional relationship between p53 and p34cdc2 in an in-vivo system and suggest that the wide variety of mutant proteins present in human tumours may fall into functionally distinct subclasses.

Blotting, Northern↗
PubMed1990

A genomic clone encoding a cryptophyte phycoerythrin alpha-subunit. Evidence for three alpha-subunits and an N-terminal membrane transit sequence.

A genomic library of Chroomonas (Cryptophyceae) DNA has been constructed in lambda EMBL4. Using a synthetic oligomer as a hybridization probe, a clone containing a phycoerythrin alpha-subunit has been obtained and sequenced. The principal alpha 1- and alpha 2-subunits of the holoprotein have been partially sequenced by sequential Edman degradation and differ from the DNA derived sequence, providing evidence for at least 3 alpha-subunit genes. The nucleotide sequence of the alpha-subunit gene is GC rich and encodes an N-terminal extension which is putatively thylakoid-lumen directing.

Amino Acid Sequence↗
PubMed1990

A phase I and pharmacokinetic study of trimetrexate using a 24-hour continuous-injection schedule.

Trimetrexate (TMTX) is an analog of methotrexate and a potent inhibitor of the enzyme dihydrofolate reductase. In this phase I study, TMTX was given intravenously to 32 patients as a constant infusion over 24 hours every 28 days. The maximum-tolerated dose of TMTX was 200 mg/m2, with myelosuppression as the dose-limiting toxicity. Other toxicities included nausea and vomiting, stomatitis, erythema and phlebitis at the site of infusion, rash and skin hyperpigmentation, and elevated serum hepatic enzymes. Two drug-related deaths occurred secondary to leukopenia and sepsis. Twenty-six patients were evaluable for antitumor response. Twenty-one patients had progressive disease, while three patients had disease stabilization. There were two partial responses observed--one in a patient with breast cancer and a second in a patient with nasopharyngeal carcinoma. TMTX pharmacokinetics were studied in 15 patients. The drug had a mean terminal half-life of 13 hours. Steady-state was not achieved during the 24-hour infusions. Only 6% of the parent compound was excreted unchanged in the urine, and CSF levels averaged less than 2% of simultaneously measured plasma levels. A dose of 150 mg/m2 is recommended for phase II trials of TMTX using this 24-hour infusion schedule.

Adult↗
PubMed1990

Transactivation of the p53 oncogene by E1a gene products.

Infection of quiescent rat kidney cells with human adenovirus is shown to transcriptionally stimulate (transactivate) the p53 oncogene. The increased transcription results in an accumulation of p53-specific mRNA in parallel with an increase in p53 protein levels, although there is a considerable delay between transcriptional activation and the detection of stable p53 mRNA and protein. The induction of p53 is detectable with two monoclonal antibodies recognizing different epitopes. The induction of p53 by adenovirus is delayed compared to induction by serum, and it occurs after the onset of adenovirus-induced cellular DNA replication. Thus, adenovirus-induced DNA replication bypasses a G0/G1 control point. Experiments with hydroxyurea show that p53 activation does not require continued cell cycling and thus is likely to be a direct consequence of viral gene expression. Finally, the induction of p53 is shown to be dependent on expression of the 289-residue product encoded by the viral E1a gene.

Adenovirus Early Proteins↗
PubMed1990

Certification for oncology nurses: maturing of a discipline.

Certification for oncology nurses shares many similarities with board certification in medicine. Within the specialty of oncology nursing, certification provides one measure of excellence and signals a commitment to oncology nursing practice. Since the beginning of oncology nursing certification in 1986, over 7,200 nurses have become certified. This article describes the certification process for oncology nurses and discusses ways in which physicians can assist in this process.

Certification↗
PubMed1990

An automatic microcomputer system for analysis of monophasic action potentials.

A computer system for rapid measurement and analysis of monophasic action potentials (MAPs) recorded in vivo was developed. MAPs recorded from the epicardium of mongrel dogs using a contact electrode were digitized by analog-to-digital conversion at a sampling rate of 1 kHz per channel for computer data acquisition. Activation time was detected using a sliding 10-point window at the location where the average positive dV/dT exceeds an adjustable threshold value in order to eliminate spurious detection due to baseline variability or motion artifact. Action potential duration (APD) was determined at 50% and 90% (APD50, APD90) repolarization levels at the first sample point below these detection levels. In addition, a tangent algorithm (APDtan) that detects peak negative dV/dT during repolarization was developed. APDtan was determined from the location of onset of activation to the intersection of tangent and baseline. APDtan allowed estimation of APD in the presence of subsequent premature beats when APD90 was not measurable. To validate activation time measurements, 4,600 action potentials were analyzed during fixed rate pacing. Over a range of paced coupling intervals from 200 to 1000 msec, an R2 value of 0.99968 and a slope of 0.9959 were obtained by linear regression between paced and calculated intervals. To validate APD measurements, 5035 action potentials were analyzed in five animals during fixed rate pacing (longer than 3 minutes) when action potential duration should be constant. Average coefficient of variation of 1.25%, 1.65%, and 1.14% were obtained for APD50, APD90, and APDtan, respectively. This algorithm provides a rapid and accurate method to analyze MAP activation and duration for basic physiological studies such as the determination of initiation of arrhythmias.

Action Potentials↗
PubMed1990

Training of village health workers in Tanzania; a comparison of two approaches.

The paper compares the costs of training for two groups of Village Health Workers (VHWs) in Tanzania, where the policy of developing a system based on Primary Health Care principles will require the training of more than 16,000 VHWs during the next decade. In the Kilombero District, one group of VHWs was trained according to the guidelines of the National Programme of the Ministry of Health, and another group followed the training programme of the Kilombero Project, based on the Swiss Tropical Institute Field Laboratory. The training scheme of the Kilombero project cost almost 80% less for one VHW, largely because it depended on on-the-spot training by local staff. The results of a first investigation of the efficacy of the training were encouraging; a long-term evaluation is in progress. The curricula for the two programmes also differed; the Kilombero programme had shorter blocks of theory, interspersed with supervised practical work, and introduced curative medicine earlier in the course. The advantage and disadvantages of the two programmes are discussed, not only in terms of cost but also in terms of their efficacy in training VHWs who will be motivated, efficient and accepted by the community.

Community Health Workers↗
PubMed1989

Development of clinically recognizable genital lesions among women previously identified as having "asymptomatic" herpes simplex virus type 2 infection.

STUDY OBJECTIVE: To determine if patients initially identified by history, clinical examination, and serologic status as having asymptomatic herpes simplex virus type 2 infection report clinically recognizable genital lesions after having a detailed instructional session on the clinical signs and symptoms of genital herpes. DESIGN: Prospective follow-up of two groups of women. SETTING: Outpatient clinic of an urban city-county hospital. PATIENTS: Two populations of women were recruited. One group was referred because they had documented asymptomatic genital herpes or were suspected of asymptomatically transmitting genital herpes to a sex partner. The other group was recruited from the hospital's general gynecologic clinic and consisted of women with herpes simplex virus type 2 antibodies who denied a history of genital herpes. INTERVENTION: Patients had a one-on-one interview describing the clinical symptoms of genital herpes. MEASUREMENTS AND MAIN RESULTS: Twelve of nineteen women with herpes simplex virus type 2 antibodies who had documented asymptomatic genital herpes or were suspected of asymptomatically transmitting infection to a sex partner, and 18 of 43 women with herpes simplex virus type 2 antibodies who were recruited from the gynecologic clinic developed clinically recognizable genital lesions during a 5-month follow-up. Symptomatic genital herpes was the most frequent gynecologic complaint identified during follow-up. CONCLUSIONS: Approximately 50% of women with herpes simplex virus type 2 antibodies who do not initially report a history of genital lesions do indeed have clinically symptomatic genital herpes. These women can be accurately counseled and taught to distinguish genital herpes from other genitourinary infections. Identification of symptomatic recurrences and counseling to avoid sexual activity during these episodes may help reduce transmission of genital herpes.

Adolescent↗
PubMed1989

The effect of UK14,304-18 (an alpha-2 adrenergic agonist) on myocardial blood flow during cardiopulmonary resuscitation.

Several recent studies have suggested that adrenergic drugs with peripheral postsynaptic alpha-2 agonist properties increase aortic diastolic pressure (ADP), and thus in the setting of CPR, may improve myocardial blood flow (MBF). This preliminary study investigated the effect of UK14,304-18, a postsynaptic alpha-2 adrenergic agonist on ADP, MBF, myocardial oxygen delivery/utilization (MDO2/MVO2), endocardial/epicardial blood flow ratio (EN/EP), coronary sinus oxygen content (CcsO2) and extraction ratio (ER) during CPR. Five swine were instrumented for MBF measurements using tracer microspheres. Catheters were also placed to measure arterial oxygen content (CaO2) and CcsO2. ADP, MBF, MDO2/MVO2, EN/EP, ER, CaO2 and CcsO2 were measured during normal sinus rhythm (NSR), and during CPR following a 10-min cardiorespiratory arrest. Following this, each animal received 2.0 mg/kg of UK14,304-18 through a right atrial line. ADP, MBF, MDO2/MVO2, EN/EP, ER, CaO2 and CcsO2 were again determined. Defibrillation was then attempted. To determine whether UK14,304-18 improved ADP, MBF and MDO2 over MVO2, compared to CPR alone, results were compared using a paired Student t-test. Statistical significance was considered at the P less than or equal to 0.05 level. No significant improvement in ADP, MBF, MDO2 or ER was noted following the administration of UK14,304-18. The lack of improvement in ADP and MBF may be secondary to a centrally acting postsynaptic alpha-2 agonist effect because of disruption of the blood brain barrier following a prolonged cardiac arrest or because of pharmacologically or structurally distinct populations of peripheral postsynaptic alpha-2 adrenoreceptors that develop in this setting.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic alpha-Agonists↗
PubMed1989

The effect of norepinephrine versus epinephrine on regional cerebral blood flow during cardiopulmonary resuscitation.

alpha-Adrenergic drugs improve cerebral blood flow (CBF) during cardiopulmonary resuscitation (CPR), in part, by reversing carotid artery collapse and by shunting blood from extracerebral to intracerebral vascular structures. Adrenergic drugs with beta 2-agonist properties may cause peripheral vasodilation, and thus may be less beneficial in this setting. The purpose of this study was to compare epinephrine (E), an alpha 1,2, beta 1,2-agonist, with norepinephrine (NE), an alpha 1,2, beta 1-agonist, on CBF during CPR. Twenty swine each weighing greater than 15 kg were instrumented for regional CBF measurements using tracer microspheres. Regional CBF was measured during normal sinus rhythm (NSR). Animals were then placed into ventricular fibrillation (VF). After ten minutes of VF, the animals received closed-chest CPR using a mechanical thumper. Regional CBF was measured during CPR. After three minutes of CPR, the animals were allocated to receive either E, 0.20 mg/kg (N = 5); NE, 0.08 mg/kg (N = 5); NE, 0.12 mg/kg (N = 5); or NE, 0.16 mg/kg (N = 5). Regional blood flows were again measured following drug administration. CBFs following drug administration were compared using an analysis of covariance adjusting for baseline differences during CPR. A Newman-Keuls multiple comparison was used to follow-up significant (P less than or equal to .05) differences. Statistical significance was considered at P less than or equal to .05. There was a clinically significant improvement in cerebral cortical flow with NE, 0.12 mg/kg, and NE, 0.16 mg/kg, compared with NE, 0.08 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

The effect of norepinephrine versus epinephrine on myocardial hemodynamics during CPR.

Alpha-adrenergic agonists improve myocardial blood flow during CPR by increasing aortic diastolic pressure. Adrenergic agonists with beta-2 properties may enhance peripheral vasodilation and may prove less beneficial during CPR. The purpose of this study was to compare epinephrine (E), an alpha-1,2; beta-1,2 agonist, versus norepinephrine, an alpha-1,2; beta-1 agonist, on myocardial hemodynamics during CPR. Twenty swine were instrumented for pressure, arterial and coronary sinus oxygen content (CAO2 and CCSO2, respectively), and myocardial blood flow measurements using tracer microspheres. CAO2, CCSO2, myocardial blood flow, myocardial oxygen delivery (MDO2) and myocardial oxygen consumption (MVO2), extraction ratio, and aortic diastolic pressure were determined during normal sinus rhythm and during CPR following a ten-minute arrest. After three minutes of CPR, the animals were allocated to receive either norepinephrine 0.08 mg/kg (n = 5), norepinephrine 0.12 mg/kg (n = 5), norepinephrine 0.16 mg/kg (n = 5), or epinephrine 0.20 mg/kg (n = 5). One minute after drug administration, all hemodynamic parameters were again determined. Three and one half minutes after drug administration defibrillation was attempted. A Newman-Keuls multiple comparison procedure was used to compare differences following drug administration. During CPR, aortic diastolic pressure averaged less than 13 mm Hg, and myocardial blood flow averaged less than 6 mL/min/100 g. All doses of norepinephrine and epinephrine improved all hemodynamic parameters over those seen during CPR. The two highest doses of norepinephrine significantly improved extraction ratio compared with norepinephrine 0.08 mg/kg (P = .04).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Drug acetylation in breast cancer.

The acetylator phenotype was determined in 100 patients with breast cancer and 100 control female subjects using isoniazid. The proportion of fast acetylators in the breast cancer patients (43%) was not significantly different from the control group (43%). We conclude that acetylator phenotype is unlikely to be an important determinant of the risk of developing breast cancer.

Acetylation↗
PubMed1989

Effect of direct mechanical ventricular assistance on myocardial hemodynamics during ventricular fibrillation.

Direct mechanical ventricular assistance (DMVA) is a method of biventricular circulatory support that employs a pneumatic device to apply both systolic and diastolic forces directly to the ventricular myocardium. This study investigated the effects of DMVA on myocardial hemodynamics when applied after a prolonged cardiopulmonary arrest. Seven swine weighting 28.3 +/- 2.5 kg were instrumented for regional myocardial blood flow (MBF) measurements using tracer microspheres. Ventricular fibrillation was then induced. After 10 min of ventricular fibrillation, CPR was initiated for 3 min. DMVA was then applied through median sternotomy. Defibrillation was attempted after 3.5 min of DMVA. If unsuccessful, DMVA was instituted for another 17.5 min and a subsequent defibrillation attempt was made. Arterial oxygen content (CaO2), coronary sinus oxygen content (CcSO2), myocardial oxygen delivery/consumption (mDO2/mVO2), extraction ratio (ER), and endocardial/epicardial blood flow ratio (EN/EP) were determined during CPR, during the initial application of DMVA (DMVA1), and after the subsequent 17.5 min of DMVA in those animals not initially defibrillated (DMVA2). Three of the seven animals were successfully defibrillated during DMVA1. After the additional 17.5 min of DMVA, only one other animal was defibrillated. There was a significant improvement in CaO2, CcSO2, MBF, mDO2, mVO2, ER, and EN/EP after DMVA1 compared to CPR. Only mVO2 and ER improved significantly after DMVA2. These findings support the concept that physical diastolic augmentation may improve myocardial hemodynamics when DMVA is applied during cardiac arrest.

Animals↗