Analgesia with femoral nerve block for anterior cruciate ligament reconstruction.

Anterior cruciate ligament reconstruction is performed routinely as an outpatient surgical procedure despite few studies of patient acceptance or postoperative patient analgesia. This study reports the first series of postoperative femoral nerve blocks as analgesia for outpatient anterior cruciate ligament reconstruction. The authors retrospectively reviewed 161 patients undergoing two incision arthroscopically assisted autograft middle 1/3 patellar tendon anterior cruciate ligament reconstruction on an out-patient basis at the authors' institution during a period of 30 months. Hospital and anesthesia records were reviewed, and 83% of patients were contacted retrospectively to survey their perceptions of the procedure and its outcome. Ninety-eight percent of the patients were discharged from the ambulatory surgery center, with 51% discharged the same day as the surgery and 47% discharged by 7:00 AM the next day. As the study progressed, the number of patients staying overnight was reduced by 50%. Ninety-eight percent of patients surveyed found femoral nerve block to be beneficial, and the same percentage thought the discharge time was appropriate. However, 69% of patients staying overnight cited reasons other than pain as factors in their stay. No significant complications were reported. Based on these results, the administration of a femoral nerve block is recommended for patients undergoing outpatient anterior cruciate ligament reconstruction because it is a highly effective form of analgesia with an excellent degree of patient satisfaction.

A role for the yeast SWI/SNF complex in DNA replication.

The yeast SWI/SNF complex is required for expression of many genes and for the full functioning of several transcriptional activators. Genetic and biochemical studies indicate that SWI/SNF uses the energy of ATP hydrolysis to antagonize chromatin-mediated transcriptional repression. We have tested the possibility that SWI/SNF might also play a role in DNA replication. A mitotic minichromosome stability assay was used to investigate the replication efficiency of a variety of autonomous replication sequences (ARSs) in the presence and absence of SWI/SNF. The stability of minichromosomes that contain ARS1, ARS309 or ARS307 is not altered by lack of SWI/SNF, whereas the functioning of ARS121 is crippled when SWI/SNF is inactivated. The SWI/SNF dependence of ARS121 does not require the replication enhancer factor, ABF1, and thus, it appears to be a property of a minimal ARS121 origin. Likewise, a minimal derivative of ARS1 that lacks the ABF1 replication enhancer acquires SWI/SNF dependence. Replacing the ABF1 binding site at ARS1 with a binding site for the LexA-GAL4 chimeric activator also creates a SWI/SNF-dependent ARS. Our studies suggest that the SWI/SNF chromatin remodeling complex can play a role in both replication and transcription and, furthermore, that SWI/SNF dependence of ARS elements is a property of both an ARS-specific replication enhancer and the overall organization of ARS sequence elements.

Femoral nerve block as an alternative to parenteral narcotics for pain control after anterior cruciate ligament reconstruction.

Anterior cruciate ligament (ACL) reconstruction is associated with significant postoperative pain, usually requiring parenteral narcotics. A prospective study of arthroscopically assisted autograft patellar tendon ACLR was initiated using Winnie's "three-in-one" femoral nerve block (FNB) as the primary means of postoperative pain control. Patient satisfaction and absence of parenteral narcotic use indicated clinical success. Of 24 patients studied, 92% had no parenteral narcotics administered following FNB. Ninety-five percent of patients believed FNB was beneficial and would request another. The average duration of pain control was 29 hours and the majority of patients (79%) believed discharge was possible within 23 hours. There were two patients who failed to respond to FNBs (8%) and no major complications. FNB is a safe, reliable, and effective form of analgesia following ACLR, eliminating the need for parenteral narcotics.

Noninvasive monitoring of end-tidal carbon dioxide tension via nasal cannulas in spontaneously breathing children with profound hypocarbia.

OBJECTIVE: To determine the correlation between end-tidal CO2 and PaCO2 measured via nasal cannulas in spontaneously breathing children with profound hypocarbia (PaCO2 < 30 torr [< 4.0 kPa]). DESIGN: Prospective evaluation. SETTING: Pediatric intensive care unit (ICU) in a tertiary care referral center. INTERVENTIONS: None. PATIENTS: Patients admitted to the ICU with a diagnosis of diabetic ketoacidosis in whom invasive arterial access was deemed necessary for clinical care. The patients were spontaneously breathing, without intubation. The study included nine patients, with an average age of 9.9 yrs (range 4 to 17) and weight of 38.7 kg (range 17 to 68). MEASUREMENTS AND MAIN RESULTS: End-tidal CO2 was sampled from nasal cannulas by a sidestream aspirator and estimated by infrared spectroscopy. The correlation between arterial and end-tidal CO2 was compared using linear regression analysis. A total of 65 arterial blood gases were obtained from the nine patients. The PaCO2 was < or = 30 torr (< or = 4.0 kPa) in 38 of the samples. The PaCO2 to end-tidal CO2 gradient was < or = 4 torr (< or = 0.5 kPa) in 64 of 65 samples and 4.8 torr (0.6 kPa) in one sample. Linear regression analysis of arterial vs. end-tidal CO2 yielded a slope of 0.99, an r2 value of .97, and a p value of .0001. CONCLUSIONS: End-tidal CO2 measurement by infrared spectroscopy provides an accurate estimation of PaCO2, even during episodes of severe hypocarbia. Its use may limit the need for invasive monitoring and/or repeated arterial blood gas analyses.

General anesthesia by mask with spontaneous ventilation during brief laparoscopic inspection of the peritoneum in children.

We prospectively examined the cardiorespiratory changes seen with general anesthesia by mask with spontaneous ventilation during brief laparoscopic inspection of the peritoneum in children. Anesthesia consisted of isoflurane in 50% oxygen/air and a caudal epidural block. The patient was allowed to ventilate spontaneously without assistance. Baseline measurements of heart rate, systolic/diastolic blood pressure (BP), end-tidal CO2 (PETCO2), tidal volume, respiratory rate, and oxygen saturation were recorded every 1 min for 5 min before the start of laparoscopy and every minute during the laparoscopic procedure. A total of 20 patients were enrolled in the study, ranging in age from 15 to 80 months (mean 40.8 months) and in weight from 10.5 to 27 kg (mean 15.9 kg). The length of the laparoscopy varied from 3 to 18 min (mean 6.9 min). No significant changes (increase or decrease of 20% from baseline) of heart rate or BP occurred. Oxygen saturation remained at 98%-100% throughout the procedure in all patients. The baseline tidal volume before the start of laparoscopy was 6.27 +/- 1.9 mL/kg and increased to 7.3 +/- 2.2 mL/kg during laparoscopy (p = 0.01). The baseline respiratory rate was 27.7 +/- 7.0 breaths/min and increased to 33.5 +/- 7.2 breaths/min during laparoscopy (p = 0.0001). PETCO2 increased from a baseline value of 37.5 +/- 6.5 to 44.6 +/- 6.8 mm Hg (p = 0.0001). The increase in PETCO2 was 10 or greater in 3 patients and exceeded 50 mm Hg in 3 patients, with a maximum value of 66 torr.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive monitoring of end-tidal CO2 via nasal cannulas in spontaneously breathing children during the perioperative period.

OBJECTIVE: To determine the correlation between end-tidal CO2 and PaCO2 values measured via nasal cannulas in spontaneously breathing children during the perioperative period. DESIGN: Prospective evaluation. SETTING: Pediatric intensive/intermediate care unit in a tertiary care referral center. PATIENTS: Thirty postoperative surgical and trauma patients aged < or = 18 yrs (average age 7.8 yrs [range 6 months to 16 yrs] and average weight 28.3 kg (range 8.5 to 69). MEASUREMENTS AND MAIN RESULTS: Spontaneously breathing, nonintubated patients with an arterial cannula in place were selected for study. End-tidal CO2 was sampled from nasal cannulas by a sidestream aspirator and was estimated by infrared spectroscopy. The difference between PaCO2 and end-tidal CO2 was compared using linear regression analysis. A total of 55 blood gas measurements were obtained on the 30 patients. The PaCO2 to end-tidal CO2 gradient was < or = 4 torr in 54 of the 55 samples. The mean PaCO2 was 39.5 +/- 3.3 torr (5.27 +/- 0.44 kPa) with a mean end-tidal CO2 value of 39.7 +/- 3.8 torr (5.29 +/- 0.51 kPa). Linear regression analysis of arterial vs. end-tidal CO2 yielded a slope of 0.992 and p = .0001. CONCLUSIONS: End-tidal CO2 measurement by infrared spectroscopy provided an accurate estimation of PaCO2 in this patient population. Its use may limit the need for invasive monitoring and/or repeated arterial blood gas analysis.

Effect of Storage of Raw and Pasteurized Goats' Milk on Flavor Acceptability, Psychrotrophic Bacterial Count, and Content of Organic Acids.

Pasteurization of raw goats' milk either at 63°C for 30 min or 72°C for 15 s within 1 d of milking ensures a better tasting product both initially and during storage at 4.5°C for 6 weeks than if the raw milk is aged for several days at 4.5°C before being pasteurized. Pasteurized milks processed from high-count raw milks aged 1 to 2 weeks had lower acceptability ratings (on a 9-point hedonic scale), which decreased further in cold storage and were independent of bacterial increases in the log phase of growth. Pasteurized milks processed from raw milk 7 or more days old were subject to rapid increases in bacterial numbers in storage if they were trace-contaminated during pasteurization even though initial counts were <100 psychrotrophs/ml. For all raw and pasteurized milks, three peaks were consistently observed from an HPLC analysis designed to monitor some organic acids. Two of the components decreased and the third appeared and increased during storage. Disappearance of one component coincided with appearance of another. These compounds may be associated with loss of flavor quality of the milk since in some instances these changes significantly correlated with the decrease in hedonic ratings of the stored milks.

Virus-specific ribonucleic acid synthesis in KB cells infected with herpes simplex virus.

The production of virus-specific ribonucleic acid (RNA) was investigated in KB cells infected with herpes simplex virus. A fraction of RNA annealable to virus deoxyribonucleic acid (DNA) was found in these cells as early as 3 hr after virus inoculation. Production of this species of RNA increased up to 6 or 7 hr after infection, at which time elaboration of virus messenger RNA (mRNA) declined. At 24 hr after infection, the rate of incorporation of uridine into this RNA was approximately one-half of the rate present at 6 hr after inoculation. Nucleotide analysis of the RNA annealable to virus DNA was compatible with that expected for virus mRNA. Centrifugation showed considerable spread in the size of the virus-induced nucleic acid, the bulk of this RNA sedimenting between 12 and 32S. Incorporation of uridine into cell mRNA, ribosomal precursor RNA, and soluble RNA was suppressed rapidly after infection. As is the case with most other cytocidal viruses investigated to date, virus-induced suppression of cell RNA synthesis appears to be a primary mechanism of cell injury.

Hydrolytic enzymes in KB cells infected with poliovirus and herpes simplex virus.

Flanagan, John F. (Duke University School of Medicine, Durham. N.C.). Hydrolytic enzymes in KB cells infected with poliovirus and herpes simplex virus. J. Bacteriol. 91:789-797. 1966.-The effect of poliovirus and herpes simplex virus infection on the activity of five hydrolytic enzymes was studied in tissue culture cells of KB type. During the course of poliovirus infection, the activity of beta-glucuronidase, acid protease, acid ribonuclease, acid deoxyribonuclease, and acid phosphatase in the cytoplasm rose to levels two- to fourfold greater than the activity present in the cytoplasm of uninfected cells. The rise in cytoplasmic activity was accompanied by a concomitant decrease in enzymatic activity bound to cell particles. Shift of enzymatic activity from the particulate to soluble state was first detected at 6 hr after poliovirus infection, coinciding with the appearance of new infectious particles and virus cytopathic effect. No net synthesis of these enzymes after poliovirus infection was found. Hydrocortisone added to the culture medium failed to affect either the titer of virus produced in the cells or the release of hydrolytic enzymes from the particulate state. Herpes simplex infection produced minimal alterations in the state of these enzymes in KB cells. It is hypothesized that the breakdown of lysosomes and release of hydrolytic enzymes accompanying poliovirus infection is produced by alterations in cell membrane permeability during the course of virus replication and by the consequent change in the ionic content of the cell sap.