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Biomedical subjects

J G Boyle

Publications and source records attributed to J G Boyle.

5 recordsLinked to original sources

T and J vertical extensions in low transverse cesarean births.

OBJECTIVE: To determine the frequency of T and J extensions in low transverse cesarean births at a regional perinatal center, identify the indications for these incisions, and evaluate the associated complications. METHODS: We reviewed the medical records of 56 patients delivered between January 1988 and November 1994 by low transverse cesarean birth requiring vertical extension of the incision into-the upper uterine segment. Cases of extension were compared with controls matched for gestational age, presentation, and indication for cesarean delivery. Data collected included demographic information, indications for extension, extension type, estimated blood loss, intraoperative complications, and length of hospital stay. Paired Student t test and McNemar test were used for statistical analysis. RESULTS: Vertical extensions were performed in 1.3% (95% confidence interval 0.42-2.26%) of low transverse incisions over a 7-year period. The most common indications were malpresentation (n = 31), poorly developed lower uterine segment (n = 12), and fetal head deeply arrested in the midpelvis (n = 6). Estimated blood loss was greater for patients requiring an extension (990 +/- 310 mL) compared with controls (790 +/- 150 mL), as were differences in preoperative versus postoperative hemoglobin and hematocrit (P < .05). Surgical complications were observed in 28 of 56 (50%) subjects with a uterine extension, including excessive blood loss (n = 20), broad ligament hematomas or extensions (n = 4), cervical lacerations (n = 4), and uterine artery lacerations (n = 4). Patients with vertical extensions also had longer hospital stays (4.6 +/- 1.6 versus 3.8 +/- 1.1 days) (P < .05). CONCLUSIONS: Low transverse uterine incisions may be inadequate for the safe delivery of a fetus in cases of malpresentation, preterm birth, and poor development of the lower uterine segment. Used to complete these difficult deliveries, T and J extensions are often associated with intraoperative complications and prolonged hospital stays compared with controls.

Adult↗

Time-of-flight mass spectrometry with an electrospray ion beam.

An electrospray ionization source has been coupled to a reflection time-of-flight mass spectrometer. By orienting the ion source perpendicular to the field-free drift region, the longitudinal energy spread of the ion packet has been substantially reduced, allowing a mass resolving power of over 1000 to be achieved for both low-mass and high-mass ions of biological interest. In addition, instrument sensitivity allows the routine detection of low-picomole and subpicomole quantities of large multiply charged species such as cytochrome c (MW = 12,360.9). The potential utility of this instrument for conducting rapid screening of chromatographic effluents is discussed in light of its simplicity, rapid scanning speed, and high sensitivity.

Mass Spectrometry↗

An ion-storage time-of-flight mass spectrometer for analysis of electrospray ions.

A preliminary design and implementation of a novel approach to electrospray-mass spectrometry are described. Based on a time-of-flight mass analysis, the instrument provides several important advantages for on-line mass analysis: 1, simplicity, ease of use and low manufacturing cost; 2, rapid scan speed, yielding quasi-instantaneous full mass scans at repetition rates up to several kHz; 3, soft ionization and accurate mass determination of extremely large analyte molecules; 4, high sensitivity.

Arginine↗