Central venous cannulation: how to do it

Central venous cannulation is an important clinical tool for the hospital doctor. A sound knowledge of applied anatomy, relative contraindications and possible complications is required to decrease morbidity and mortality. This article seeks to provide the working knowledge required to perform and use central venous cannulation safely.     

Lung cancer practice guidelines: lessons learned and issues addressed by the Ontario Lung Cancer Disease Site Group

PURPOSE: The primary objective was to identify the lessons learned and issues addressed by the Disease Site Group (DSG) developing guidelines on lung cancer for practitioners in the province of Ontario. METHODS: The minutes of the Ontario Lung Cancer Disease Site Group (LCDSG) and the meeting notes of a medical sociologist who attended all LCDSG meetings were reviewed to identify the disease-specific and generic issues addressed by the LCDSG during guideline development. RESULTS AND CONCLUSION: The Ontario LCDSG has completed three practice guidelines and has five evidence-based recommendations (EBRs) in production. Topics for guideline development were selected on the basis of known practice variability (eg, advanced-stage non-small-cell lung cancer [NSCLC]); the size of the patient population that could potentially be affected by the guideline; results of phase II trials of new and potentially expensive agents (vinorelbine, paclitaxel, and docetaxel); and randomized controlled clinical trials that support new practice standards (combined modality therapy for unresectable stage III NSCLC). The wording of each EBR reflects the strength and quality of the evidence in support of the treatment option, the primary outcome(s), and the individual physician and discipline values concerning treatment outcomes in the absence of known patient values.     

Reference values of common blood chemistry analytes in healthy population of Rawalpindi-Islamabad area

The reference values of common blood chemistry analytes in healthy population, aged newborn to 80 years, of Rawalpindi Islamabad area were determined at AFIP, Rawalpindi. A total of 2115 healthy subjects, 1206 males and 909 females, were included in the study. Plasma glucose was analysed by GOD/POD, serum cholesterol by CHOD/PAP, triglycerides by GPO/PAP, urea by urease/GLDH, creatinine by Jaffe' rate reaction, uric acid by uricase, total bilirubin by Jendrassik and Grof, total protein by biuret, alanine transaminase (ALT) by optimized IFCC and alkaline phosphatase (AP) by optimized DGKC method. The between batch CVs of all the parameters were within acceptable quality goals. The reference values were calculated using 2.5 and 97.5 percentiles as lower and upper limits (95% CI). In healthy adult males the reference values were: fasting plasma glucose, 3.6-6.0 mmol/l; serum cholesterol; 3.2-6.6 mmol/l; triglycerides, 0.6-2.3 mmol/l; urea, 2.8-6.4 mmol/l; creatinine, 65-132 umol/l; uric acid, 164-430 umol/l; total bilirubin, 5-18 umol/l; total protein, 57-83 g/l; ALT, 15-45 U/l and AP, 185-620 U/l. The values in adult females, children and elderly subjects were slightly different than adult males. The reference values of our population show mild to moderate differences from the other Asian, European and American populations. It is recommended that reference values of different biochemical investigations should be established in various areas of Pakistan to make appropriate use of such investigations.     

Oestrus, ovulation and peri-ovulatory hormone profiles in tethered and loose-housed sows

Multiparous sows that had been tethered during lactation were put in two different housing conditions after weaning (Day 0); the sows were either tethered by neck chain, or individually housed in a pen of approximately 6 m2. After two months, ten tethered and eleven loose housed sows were used to assess stress and reproductive parameters. Stereotypic behaviour after the afternoon feeding was assessed from Day 18 onwards; at Day 53 stereotypic behaviour tended to occur during a higher percentage of time in the tethered sows (P = 0.11) and at Day 66, the differences were significant (tethered, 78 +/- 5 vs. loose-housed, 40 +/- 10% of time (mean +/- sem); P = 0.03). At Day 35 and 55, cortisol profiles after afternoon feeding were similar for the two groups of sows (P > 0.10). Around oestrus (approximately Day 64), the profiles of oestradiol-17 beta, luteinizing hormone and progesterone were measured and proved to be similar for both treatment groups (P > 0.10). The duration of oestrus was shorter in the tethered sows (42 +/- 4 vs. 63 +/- 2 h; P < 0.001) and, consequently, the timing of ovulation during oestrus (h after onset of oestrus) was advanced in the tethered sows (28 +/- 2 vs. 41 +/- 2; P < 0.001). The duration of ovulation did not differ (tethered, 2.9 +/- 0.5 vs. loose-housed, 2.1 +/- 0.2 h; P = 0.16). The sows were sacrificed at Day 5 after ovulation; ovulation rate, fertilization rate, embryo development and embryo diversity were similar for the two groups, as were adrenal weight and size of adrenal cortex. Duration of oestrus and the levels of stereotypies at Day 60 tended to be negatively related in the tethered sows (P = 0.07), but not in the loose-housed sows (P = 0.65). In conclusion, sows that had been tethered during pregnancy and lactation, and were housed loose or were tethered again at weaning within two months differed both in stereotypic behaviour and in duration of oestrus, without apparent effects on reproductive hormones.     

In vitro bonding of adhesive resin to dental alloys and dentine

The purpose of this in vitro investigation was to compare the shear bond strength of sandblasted, tin-plated and metal primed Type II gold alloy bonded to Ni-Cr alloy, as well as sandblasted Type II gold bonded to dentine, using two different adhesive resin cements. All bonding surfaces were treated with C&B-Metabond (Parkell, CB) or Imperva Dual (Shofu, ID), according to the manufacturers' instructions. In all, 20 sandblasted, 20 tin-plated and 20 metal-primed gold cylinders were bonded to Ni-Cr, and 20 sandblasted gold cylinders bonded to dentine. Bonds were stressed to failure using a shear load in an Instron testing machine. Data were calculated, statistically analysed (ANOVA and Student-t-test), and the fracture sites examined in a SEM. The CB and ID systems demonstrated significantly higher bond strengths (p < 0.01) when the gold was tin-plated, but CB demonstrated significantly lower bond strengths (p < 0.01) when the gold was pre-treated with metal primer. CB always demonstrated significantly higher metal (p < 0.01) and dentine (p < 0.05) bond strengths than ID.     

Anticoagulation in children with mechanical valve prostheses

BACKGROUND: Clotting complications in patients with mechanical valve prostheses can be prevented with either warfarin sodium (Coumadin; DuPont, Wilmington, DE) or antiplatelet agents. In children, it is not known whether one treatment regimen is more effective or safe than the other. METHODS: We prospectively followed up 64 children and young adults (aged 18 years or younger at implantation) with a mechanical valve on the left side of the heart, from October 1986 through October 1996. Forty-eight patients were treated with Coumadin and 16 with aspirin and dipyridamole. The two groups were similar in age, sex, valve location and size, mean length of follow-up, and operative indication. There has been a total follow-up of 272 patient-years on Coumadin and 116 patient-years on aspirin and dipyridamole. RESULTS: There was no difference between the two groups in survival or freedom from thromboembolism. Bleeding occurred more often in the patients taking Coumadin, but this difference was not statistically significant. Analysis of the literature showed thromboembolism and bleeding rates to be similar in the patients receiving Coumadin and those receiving antiplatelet agents. CONCLUSIONS: Coumadin and the combination of aspirin plus dipyridamole provided similar protection against complications in this group of children and young adults with left-sided St. Jude (St. Paul, MN) mechanical valves. The choice between the two regimens may depend on other factors, such as patient preference and convenience.     

Contrast hysterosonography: an efficient means of investigation in gynecology. Review of the literature

The structure of WA8242B, a potent novel inhibitor against phospholipase A2, was fully characterized by spectroscopic methods and chemical degradation. The success of total synthesis of WA8242B confirmed the structure and allowed the pharmacological study of WA8242B. The structures of WA8242A1 and A2 were also described.     

Gestational diabetes is a herald of NIDDM in Navajo women. High rate of abnormal glucose tolerance after GDM

OBJECTIVE: To estimate the rate of deterioration of glucose tolerance and evaluate risk factors for development of NIDDM in Navajo women with a history of gestational diabetes mellitus (GDM). RESEARCH DESIGN AND METHODS: A retrospective analysis of 111 GDM deliveries over a 4-year period, 1983-1987, was conducted in 1994 to determine glucose tolerance status. Patients who had not developed NIDDM were recalled for a 2-h glucose tolerance test (GTT). Tested and non-tested patients were compared, as estimate of conversion to NIDDM was calculated, and risk factors for NIDDM were evaluated. A life-table analysis was developed to estimate the probability of NIDDM after GDM. RESULTS: At the time of chart review, 32 patients (29%) had already been diagnosed with NIDDM. Of the patients, 79 were offered GTT testing, and 56 (71%) returned for follow-up; 15 were diagnosed with NIDDM and 17 with impaired glucose tolerance (IGT); 47 (42%) and 64 (58%) patients in the cohort had developed NIDDM or NIDDM/IGT at the conclusion of the study period. Patients who developed NIDDM had greater BMIs, parity, and infant weights. Fasting blood glucose > 5.83 mmol/l, GTT > 41.63 mmol/l, and recurrence of GDM were associated with later NIDDM. A life-table analysis estimated a 53% likelihood of having NIDDM at an 11-year follow-up; a second model, based only on patients with known NIDDM status, predicted a 70% rate of NIDDM at an 11-year follow-up. CONCLUSIONS: A high proportion of Navajo women with GDM progressed to NIDDM. Postpartum counseling and periodic GTTs are recommended.     

Characterization of soluble gp130 released by melanoma cell lines: A polyvalent antagonist of cytokines from the interleukin 6 family

gp130 acts as a common transducing signal chain for all receptors belonging to the interleukin (IL)-6 receptor family. The IL-6-related cytokines [IL-6, IL-11, oncostatin M (OSM), leukemia inhibitory factor, ciliary neurotrophic factor, and cardiotrophin] often modulate tumor phenotype and control the proliferation of many tumor cell lines. We demonstrate that melanoma cell lines release, in vitro and in vivo (when transplanted in nude mice), soluble gp130 (sgp130), a potential antagonist of cytokines from the IL-6 family. Biochemical analysis revealed that sgp130 derived from melanoma patients' sera or from culture supernatants of melanoma cell lines is a Mr 104,000 protein that resolved after deglycosylation as a Mr 58,000 protein. PCR and Northern blot analysis only identified one gp130 membrane mRNA, suggesting that the soluble form of gp130 is generated by proteolytic cleavage. OSM reproducibly increases sgp130 released by melanoma cell lines, whereas leukemia inhibitory factor stimulates the production of sgp130 in only one of three cell lines tested. This tumor-derived sgp130 is functional because it binds in solution to the IL-6-soluble IL-6 receptor (gp80) complex. Recombinant sgp130 inhibits the growth inhibitory activity of the IL-6-soluble IL-6 receptor complex and OSM on some melanoma cell lines. Therefore, this soluble gp130 represents a natural antagonist of cytokines from the IL-6 family.