Establishing a PNP faculty practice clinic for Medicaid EPSDT screening

Faculty practice added a new dimension to teaching clinical skills in a Pediatric Advanced Practice Nursing program. It offered the student immediate feedback concerning didactic knowledge and clinical skills and added consistency to learning obtained in the classroom setting. Inclusion of the Medicaid EPSDT program further enhanced student learning by offering a framework of comprehensive services that the student could offer to the patient in providing holistic well-child care. Research opportunities for faculty and students are also prevalent with the large quantity of data available from administration of the EPSDT program. In addition, many children from indigent settings who would not otherwise receive routine well-child care have been given the opportunity because of this program. The use of a faculty practice model that provides the Medicaid EPSDT screening seems to meet the well-child needs of faculty, students, and patients alike and provides an education/service model congruent with the preventative goals of health care reform today.

Anti-emetic profile of a non-peptide neurokinin NK1 receptor antagonist, CP-99,994, in ferrets

In the ferret, 5-HT3 receptor antagonists are effective in controlling emesis produced by cytotoxic agents or radiation. To investigate the possibility that substance P has a role, as well as 5-HT, in the emetic reflex pathway, we have examined the anti-emetic effects of a NK1 receptor antagonist (racemic CP-99,994) in the ferret. Racemic CP-99,994 was effective against a range of emetogens, comprising cytotoxic drugs, radiation, morphine, ipecacuanha and copper sulphate.

The pediatric nurse practitioner and the physician assistant: how are we different?

Changing health care needs over the past 30 years have created new roles for professionals in advanced health care practice settings. As new roles continue to evolve, educational preparation and clinical experiences must be considered when determining the most appropriate health care provider for a particular specialization. Although similarities exist between the PA and PNP, the extent of pediatric didactic and clinical experiences is limited in most PA programs. Only one program is identified by the American Academy of PAs as a child health PA program. PNP education provides the nurse in an advanced practice role with an extensive background in normal growth and development, family counseling, health promotion, and management of common pediatric problems and chronic illnesses. The PNP is a registered nurse who is experienced in the care of children before pursuing an advanced degree as a PNP. In comparison, many PAs are not required to hold a professional degree before enrollment in a PA program. Although students entering PA programs may have experience in health-related fields before enrollment, few are specialized in the care of children. The PA program is designed to prepare the student to assist the physician with diagnosis and treatment in primary care with limited exposure to pediatrics. In comparison, the PNP spends the entire educational program of study gaining expertise in the care of children from infancy to adolescence. Because of advanced educational preparation, the PNP is in a unique position to contribute substantially to the total care of the child and family.

Auditory evoked response and awareness: a study in volunteers at sub-MAC concentrations of isoflurane

We have investigated the relationship between the auditory evoked response (AER) and simple tests of conscious awareness at four end-expiratory concentrations (0.0, 0.1, 0.2 and 0.4 MAC) of isoflurane in oxygen in each of eight anaesthetist volunteers, in random order, at least 1 week apart. The early cortical AER was recorded from electrodes at the vertex and inion. Amplitudes of the waves Pa, Nb and Pc and latencies of the waves Na, Pa, Nb, Pb and Nc were measured. All the AER variables were highly significantly related to end-expiratory anaesthetic concentration. Amplitudes decreased and latencies increased progressively with increasing anaesthetic concentration. The AER variables were also highly significantly related to the level of response. Amplitudes were greatest and the latencies shortest when there was full response to command. (Nb latency increased from 47.5 to 54.5 ms between partial and no response.) The close correlation between the effects of concentration and level of response, and between concentration and the AER implied that it was difficult to demonstrate those changes in the AER which specifically relate to changes in response. At 0.2 MAC, however, which was the concentration at which all subjects showed some deficit, the response to a shock word was distinguished clearly by Nb latency. In eight of 24 possible comparisons (eight AER variables and three types of psychological test) the AER fitted the response more closely than concentration.

Age-related asymmetry on a cued-listening task

We report results on a cued-listening task designed to simulate the listening problems commonly described by individuals with sensorineural hearing loss, especially those experienced by elderly persons. Against a background of multitalker babble, the subject detected targets embedded in continuous discourse. Noncoherent segments of this discourse were presented simultaneously from loudspeakers on the right and left sides. A signal light cued the side to be monitored during a listening trial. The overall difficulty of the task was manipulated by variation of the message to competition intensity ratio. A sequence of listening trials, half-cued to the right side, half cued to the left side, was executed at each of four message to competition intensity ratios. Nineteen young adults with normal hearing and 28 elderly persons with presbyacusic hearing loss were evaluated. All subjects, young and elderly, were able to complete the cued-listening task successfully. Results showed a small but significant right-side advantage in the young group and a substantial right-side advantage in the elderly group. The application of the testing technique to the evaluation of hearing aid performance is illustrated in two elderly persons.

Prophylactic intravenous immunoglobulin in HIV-infected children with CD4+ counts of 0.20 x 10(9)/L or more. Effect on viral, opportunistic, and bacterial infections. The National Institute of Child Health and Human Development Intravenous Immunoglobulin Clinical Trial Study Group

OBJECTIVE

To evaluate the efficacy of intravenous immunoglobulin (IVIG) for prevention of viral, opportunistic, and minor bacterial infections in children infected with human immunodeficiency virus (HIV).

DESIGN

Randomized, double-blind, placebo-controlled, outpatient clinical trial comparing subjects treated with 400 mg of IVIG per kilogram of body weight every 28 days with those given albumin placebo.

SETTING

Twenty-eight clinical centers in mainland United States and Puerto Rico.

PATIENTS

Three hundred seventy-six children infected with human immunodeficiency virus with clinical or immunologic evidence of HIV disease, 313 of whom had entry CD4+ counts of at least 0.20 x 10(9)/L (greater than or equal to 200/mm3).

MAIN OUTCOME MEASURES

The incidence of laboratory-proven and clinically diagnosed viral, opportunistic, and bacterial infections.

MAIN RESULTS

Viral infections and minor bacterial infections contributed more frequently to morbidity in children with entry CD4+ counts of at least 0.20 x 10(9)/L (together over five times as frequent) than did serious bacterial infection, the primary outcome measure of the trial. Opportunistic infections occurred at a similar rate as laboratory-proven serious bacterial infections. In this group of children, IVIG was significantly associated with a decrease in the rate of viral infections and minor bacterial infections per 100 patient-years (36.0 vs 54.0 episodes of viral infection per 100 patient-years, IVIG vs placebo, P = .01; and 115.1 vs 159.7 episodes of minor bacterial infection per 100 patient-years, IVIG vs placebo, P = .02), as well as a decrease in the rate of serious bacterial infections per 100 patient-years (26.4 vs 48.2 episodes per 100 patient-years; P = .002). There was no apparent difference in the rate of opportunistic infections between treatment arms.

CONCLUSIONS

Beneficial effect of IVIG was seen across multiple infectious outcome measures, with reductions in serious and minor viral and bacterial infections observed in children with entry CD4+ counts of at least 0.20 x 10(9)/L.

Hairy cell leukemia and autoimmune hemolytic anemia

A case of hairy cell leukemia (HCL) presenting as autoimmune hemolytic anemia (AHA) is described. A 40-year-old woman presented with severe hemolytic anemia. The morphological and immunological studies of bone marrow and spleen revealed a hairy cell leukemia. Although autoimmune diseases are a well known complication of HCL this is the first description of AHA as a complication of HCL.

Somatosensory and auditory evoked responses recorded simultaneously: differential effects of nitrous oxide and isoflurane

Auditory (AER) and somatosensory evoked responses (SSER) were recorded simultaneously in eight patients under anaesthesia before surgery. We studied the effects of equi-MAC end-expiratory concentrations of isoflurane (0.65-0.75%) and nitrous oxide (60-65%). The anaesthetics were changed at random in three consecutive 10-min periods so that each patient received both drugs. From the AER recorded from the vertex and inion, Pa and Nb latency and amplitude were measured. N13, P20 latency and N13 amplitude were measured from SSER recordings from the neck and P15, N20, P25, N35, P45 latency and P15-N20, N20-P25, P25-N35 and N35-P45 amplitude from the scalp over the hand area of the sensory cortex. Compared with nitrous oxide, isoflurane significantly increased the latencies of the AER waves Pa (P = 0.02) and Nb (P = 0.02), and the SSER waves N20 (P = 0.001) and P25 (P = 0.04). We were unable to demonstrate significant differences in Pa and Nb amplitude between isoflurane and nitrous oxide that we had seen previously. However, the amplitude of the SSER wave N20 was reduced significantly by nitrous oxide compared with isoflurane (P = 0.0004). This wave (N20) is thought to emanate from the thalamo-cortical radiations, and our findings may be explained by an analgesic effect of nitrous oxide mediated by endogenous opioids.

Acoustic reflex abnormalities in cranial-cervical dystonia

Previous anatomic and physiologic studies suggest brainstem dysfunction in cranial-cervical dystonia. To further explore this, we studied suprathreshold acoustic reflex waveforms in 15 such patients. A unique feature of this technique is its ability to reject movement artifacts before averaging the acoustic reflex waveforms. Thirteen patients (87%) showed some abnormality in reflex waveform morphology. There were both amplitude and latency abnormalities. These findings support the hypothesis that cranial-cervical dystonia reflects dysfunction of the brainstem.

Memory deficits in workers suffering from hard metal disease

This study examined memory functioning on the Wechsler Memory Scale-Revised in a group of adult tungsten carbide workers with hard metal disease and a group of matched controls. The hard-metal-exposed group of workers showed memory deficits related to difficulties in attention and verbal memory, with an apparent sparing of visual-spatial memory. Implications of this finding for future research are discussed.

Anti-mouse IgM immunoglobulin protects weanling mice from Coxsackievirus infection

Mice treated from birth with rabbit anti-mouse IgM antiserum (anti-mu), although immunosuppressed in regard to B cell function, may paradoxically be protected when challenged with certain viruses. Our early studies indicated that short term treatment of weanling mice protected against Semliki forest virus, herpes simplex virus, and Coxsackievirus B1. For this study, the murine model of Coxsackievirus B1 infection was chosen to determine if specific anti-mu immunoglobulin (anti-mu Ig) would protect and whether protection could be correlated with antiviral activity in certain organs. Weanling Balb/c mice were treated intraperitoneally (i.p.) with either affinity purified anti-mu Ig or purified normal rabbit (NR) Ig two consecutive days prior to i.p. challenge with Coxsackievirus B1. Mortality of anti-mu Ig treated mice was significantly lower than controls (3.4% vs 89%, P less than 0.001). Importantly, this purified anti-mu-induced protection correlated well with reduced levels of virus in blood and certain organs, especially brain. This decrease was not attributed to interferon (IFN) or virus-specific neutralizing (NT) antibody or enhanced cellular cytotoxicity. Anti-mu treatment appears to inhibit virus replication and/or enhance clearance of virus from target organs. The data indicate that a unique antiviral activity is activated by anti-mu treatment, and can be passively transferred to and protect recipient mice. The murine model of Coxsackievirus disease appears to be well suited for use in the elucidation of the mechanism of this protection.

In vitro galactosylation of a 110-kDa glycoprotein by an endogenous cell surface galactosyltransferase correlates with the invasiveness of adrenal carcinoma cells

We have examined the role of a cell surface galactosyltransferase, laminin, and laminin-binding protein (receptor) in the invasion of clonal derivatives of a murine adrenal carcinoma cell line. Although a 10-fold variation was found in the ability to invade a reconstituted basement membrane matrix, levels of intracellular laminin and the laminin-binding protein were shown to be present and secreted equally in all lines. Of the eight lines tested, seven showed a correlation between invasion and the incorporation of [3H]galactose from UDP-[3H]galactose into a 90- to 110-kDa protein. One noninvasive line (clone HSR), however, retained high galactosyltransferase activity yet could not galactosylate the endogenous 90- to 110-kDa substrate. Interestingly, this clone was unable to attach to laminin. Although high galactosyltransferase activity can be consistent with cells of high invasiveness, our results suggest that the galactosylation status of a 90- to 110-kDa Y1 cell surface glycoprotein is most indicative of invasion potential.

Rehabilitation of the mastectomy patient: a randomized, blind, prospective study

After biopsy confirmation of breast carcinoma, women who were scheduled to undergo a modified radical mastectomy had demographic data collected, goniometric measurements of shoulder flexion and abduction, and functional evaluation of the ipsilateral shoulder performed, and upper extremity circumferential measurements at five levels determined. Patients were then randomly assigned either to a group that received immediate postoperative physical therapy or to one that did not. Results represent the combination of data from a pilot study and this subsequent study following appropriate statistical analysis. Sixty-four women in the treatment group showed a statistically significant increase in shoulder range of motion in both abduction and flexion as compared to 51 women who received no physical therapy. The treated group also had fewer problems with five of the six upper extremity functional tasks that were assessed. There were no significant differences between the groups for length of hospital stay, postoperative complications, or upper extremity edema. The authors conclude that early physical therapy intervention makes a significant contribution to return to normal function without increasing the incidence of postoperative complications or prolonging hospital stay.

In situ hybridization analysis of myelin gene transcripts in developing mouse spinal cord

We analyzed the location and abundance of transcripts for the 4 CNS myelin protein genes, myelin basic protein (MBP), proteolipid protein (PLP), myelin-associated glycoprotein (MAG), and 2',3'-cyclic nucleotide phosphohydrolase (CNP), in the mouse cervical spinal cord from the time of rapid myelination until adulthood (8-45 d). In the white matter, maximal levels of transcripts were found for each of the myelin genes at the peak of myelination (8 d). Total MBP and PLP mRNAs stayed high until 20 d and showed a minor decrease thereafter. In contrast, MAG and the MBP exon 2 containing transcripts (coding for the 21.5 and 17 kDa MBP isoforms) decreased sharply between 8 and 20 d, suggesting that high levels of these transcripts are needed primarily during the initiation of myelination. CNP transcripts were less abundant, maintained high expression until 20 d, and then decreased sharply. PLP, MAG, and CNP transcripts were clustered in the oligodendrocyte cell body, while MBP mRNAs were scattered throughout the cell body and processes. In contrast to the white matter, all these myelin specific transcripts in the gray matter showed a marked increase from 8 to 20 d, as did the number of oligodendrocytes identified by CNP immunostaining. MAG transcripts were found in white matter and in satellite and other oligodendrocytes of the gray matter but not in neurons identified by their expression of neurofilament transcripts. The results of our quantitative in situ hybridization study are in good agreement with those of previous molecular studies and provide new information on the cellular and topographic distribution of myelin-specific mRNAs during myelination.

Hamstring release for knee flexion contracture in spastic adults

Thirty adults (17 male and 13 female patients) with spastic disorders were treated by hamstring releases of 46 extremities. The diagnoses were stroke, traumatic brain injury, spinal cord injury, multiple sclerosis, and anoxia. The mean age at surgery was 38.6 years. Three extremities had partial release of the hamstring tendons behind the knee; the remaining 43 extremities had a complete release. The average position of the knee was 61.4 degrees of flexion preoperatively and 6 degrees postoperatively. The follow-up period averaged 21.3 months. Preoperatively, 87% of patients were nonambulatory. Following hamstring release 43% became ambulatory and 17% had gained the ability to transfer. Complications included two stroke patients with severe peripheral vascular disease; one developed a large nonhealing sore of the ankle and the other developed gangrene of the foot. Both patients required amputation. Three other patients developed recurrent flexion contractures that have since been rereleased with good results.

Influence of acute isocapnic hypoxia on bronchial calibre and "expiratory reserve" volume in dogs

The effects of hypoxia on bronchial calibre were investigated in anaesthetized dogs using a computer-aided forced airflow oscillation technique which derived specific lower airways conductance (sGlaw) and "expiratory reserve volume" (ERV). Measurements were made with inspired oxygen concentrations varying from 40% to 10%. sGlaw tended to be slightly reduced (indicating bronchoconstriction) by decreasing the oxygen concentration from 40% to 15%, these changes being statistically significant after the administration of atropine. ERV was unaffected by changes in oxygen concentration from 40% to 15%, but was significantly reduced during ventilation with 10% oxygen. This effect was reversed by re-oxygenation and was not abolished by prior administration of atropine. It was concluded that both bronchoconstriction and changes in lung volume may be responsible for changes in airway resistance during hypoxia.

Approaches to senior care #3. Orthopaedic management of the stroke patient. Part II: Treating deformities of the upper and lower extremities

Cerebrovascular accidents are among the most serious medical problems in the United States. In Part I of this report, the pathophysiology, types of impairment, and evaluation of the stroke patient were discussed. In this report, Part II, the management of extremity deformities will be reviewed.

Antagonism of morphine-induced respiratory depression with nalmefene

The duration of respiratory depression induced by morphine 10 mg/70 kg was studied following the administration of one of two opioid antagonists. Respiratory measurements included: (i) the ventilatory response to carbon dioxide, described in two ways--the minute ventilation at an end-tidal carbon dioxide partial pressure of 8 kPa (VE8) and the log slope of the ventilatory response to carbon dioxide; (ii) resting end-tidal carbon dioxide partial pressure; (iii) rate of ventilation. One hour after administration of morphine, one of the following was given i.v.: nalmefene 0.4 mg/70 kg; naloxone 0.4 mg/70 kg (low dose); naloxone 1.6 mg/70 kg (high dose); or saline placebo. The depression of VE8 by morphine was antagonized by all three treatments for the 1.5 h after the injection. However, for the 1.5-6 h after antagonist, VE8 following naloxone became depressed, whereas VE8 after nalmefene remained significantly increased compared with other treatments. Nalmefene restored the slope of the ventilatory response to baseline for 6 h and differed significantly from low but not high dose naloxone. Resting end-tidal carbon dioxide measurements demonstrated that nalmefene activity exceeded that of low but not high dose naloxone over the 1.5-4.5 h period. Rate of ventilation was not different between treatments.

Current status of functional lower extremity surgery in adult spastic patients

Ten percent of upper motor neuron spastic patients are candidates for functional surgery. If the main cause of the disability is abnormal muscle tone and not sensation, balance, cognition, or perceptual problems, good results from tendon lengthening or transfers are to be expected. The preoperative work-up should consist of examination, trial orthoses, nerve blocks, and most importantly dynamic electromyography. Releases or neurectomies are generally done in nonfunctional patients. Phenol blocks are a temporizing procedure during the phase of neurologic recovery. The patients all tolerated the anesthesia well, and the surgical risks are the same as in other lower extremity procedures.

Group A streptococcal infection in children younger than three years of age

We evaluated 758 sick children younger than 3 years of age for Group A beta-hemolytic streptococcal (GABHS) upper respiratory infection (URI) to determine the usual clinical presentation of the disease in this age group, indications for culture and the optimal site(s) from which to isolate the organism. GABHS infection was documented in 35 subjects (4.6%). The classic presentation (as proposed in the 1940s) of GABHS URI in children younger than 3 years of age was not confirmed by this study. In 32 of the GABHS cases there were pharyngitis, common cold symptoms or both, and these were associated with acute otitis media 10 times and with otitis media with effusion 3 times. Clinical impetigo was associated with GABHS URI (4 of 32 cases). GABHS URI would not have been documented in 6 of 32 cases if cultures of the anterior nares had not been performed. Children between 18 and 36 months of age were more likely to have GABHS disease than were younger children. Hoarseness and vomiting occurred less frequently in children younger than 36 months with GABHS infection than in those of that age who had non-beta-hemolytic streptococcal illnesses. A history of two or more siblings at home or a family member with a recent streptococcal infection and the presence of irritability, a reddened throat or palate or uvular edema were each associated with GABHS URI. We concluded that sick children between 18 and 36 months of age with a reddened throat should have cultures taken of the throat and anterior nares for GABHS.(ABSTRACT TRUNCATED AT 250 WORDS)

Approaches to senior care #2. Orthopaedic management of the stroke patient. Part I. Pathophysiology, limb deformity, and patient evaluation

Cerebrovascular accidents remain one of the most serious medical problems in the United States. They are responsible for 200,000 deaths per year and are the leading cause of hemiplegia in the adult. The purpose of these reports is to review the orthopaedic aspects of stroke rehabilitation, with emphasis on functional defects, evaluation of the patient, and methods of treatment. Part I will discuss the pathophysiologic changes and patient evaluation. Part II will discuss the surgical and nonsurgical management of extremity deformities.

Effects of xylazine and acepromazine on bronchomotor tone of anaesthetised ponies

The effects of xylazine (an alpha 2-adrenoceptor agonist) and acepromazine (an alpha-adrenoceptor antagonist) on bronchomotor tone were investigated in seven anaesthetised, apnoeic ponies using a computer aided forced oscillation technique, which separates changes in bronchial calibre from changes in lung volume. Both agents produced bronchodilatation and a decrease in lung volume.

Effect of surgical stimulation on the auditory evoked response

Previous studies have shown a dose-related effect of a number of general anaesthetic agents on the early cortical waves in the auditory evoked response (AER). In this study the effect of surgical stimulation on these waves was examined in 11 patients anaesthetized with thiopentone, nitrous oxide and halothane and paralysed with pancuronium. The inspired nitrous oxide concentration and end-tidal halothane concentration were held constant at 70% and 0.3%, respectively, and baseline AER recordings were made. Following surgical stimulation there was a progressive and significant increase in the amplitude of waves Nb and Pb/Pc. Unambiguous autonomic responses were seen in three patients, but these were not significantly correlated with changes in the AER. We conclude from this, and previous studies, that the amplitude of cortical waves in the AER are sensitive not only to anaesthetic concentration but also to surgical stimulation. The AER may, therefore, provide a useful index of depth of anaesthesia, that is the balance between the effects of surgical stimulation and anaesthetic depression on central nervous system activity.

Nondetectable levels of interferon gamma is a critical host defense during the first day of herpes simplex virus infection

Previous studies have demonstrated the importance of IFN alpha/beta in resistance to primary viral infections. However, the role of IFN gamma in primary infections is unclear. The present studies were undertaken to determine whether IFN gamma induction was an important early host defense against primary HSV infection. The approach was to block the IFN gamma response with antibodies to IFN gamma prior to infection and at various times post-infection (p.i.). The data indicates that treatment of mice with anti-IFN gamma prior to infection enhanced mortality (89% vs 37%). Anti-IFNs given at various times post HSV challenge proved most effective within the first 24 h of infection. The above results suggest for the first time that IFN gamma mediates important host defense(s) early during primary HSV infection. Similar results were obtained using antibody to IFN alpha/beta.

Effect of halothane, enflurane and isoflurane on bronchomotor tone in anaesthetized ponies

The effects of halothane, enflurane and isoflurane on bronchial calibre were investigated in five anaesthetized ponies using a computer-aided forced airflow oscillation technique to derive specific lower airways conductance (s.Glaw) and expiratory reserve volume (ERV). All the agents tended to increase s.Glaw (indicating bronchodilatation), but ERV was reduced by halothane and enflurane, and increased by isoflurane. It was concluded that the effects of these agents on bronchomotor tone were similar to those which occur in man. However, the reasons for the differences in their effects on ERV compared with those found in man remain to be determined.

Prophylactic effect of aminophylline and salbutamol on histamine-induced bronchoconstriction

The effect of salbutamol 200 micrograms aerosol, i.v. high-dose aminophylline 670 mg or placebo (aerosol and infusion) on bronchomotor tone were compared in normal volunteers before and after bronchial provocation with histamine aerosol 500 micrograms. The study was a double-blind cross-over design. Specific airways conductance of the lower airway (s. Glaw) was measured using a forced airflow oscillation technique. All subjects receiving aminophylline had tremor and irritability, whereas after salbutamol there were no noticeable systemic or psychological effects. Before the administration of histamine, salbutamol caused significant bronchodilatation compared with control: aminophylline did not induce a significant change in airway conductance. The effect of histamine administration on s. Glaw was only partially blocked by the high dose of aminophylline, but was completely blocked by salbutamol.

Prospective study of perinatal transmission of Chlamydia trachomatis

During a five-year period, 262 (4.7%) of 5,531 pregnant women had positive cervical cultures for Chlamydia trachomatis, and 131 of their infants were followed up prospectively to ascertain the outcome of chlamydial exposure during the birth process. Culture-confirmed inclusion conjunctivitis of the newborn was seen in 23 (18%) of the infants. Chlamydial pneumonia was diagnosed in 21 (16%) of the infants at risk. Chlamydia trachomatis was recovered from 47 of the infants (36%), while 79 (60%) showed serologic evidence of infection. Subclinical rectal and vaginal infections were detected in 14% of infants at risk. In our population, 2.8% of newborn infants show serologic evidence of perinatal chlamydial infection and 1.4% develop either chlamydial pneumonia or conjunctivitis. Incidence rates of this magnitude indicate the need for programs aimed at preventing perinatal transmission of C trachomatis.

Effect of isoflurane on bronchomotor tone in man

Twenty patients were anaesthetized with thiopentone, the trachea intubated and the lungs ventilated with 70% nitrous oxide and oxygen. Normocapnia was maintained and, following control measurements of the specific conductance of the lower airways (s.Glaw), either 1.7% isoflurane or 1.3% halothane was added to the inspired gas mixture, 10 patients receiving each drug. s.Glaw was measured repeatedly during the next 30 min. There was a tendency for s.Glaw to increase--indicating a reduction in bronchomotor tone--during the administration of isoflurane, the effect approaching statistical significance. The administration of halothane was associated with a significant increase in s.Glaw. There was a statistically significant increase in the expiratory reserve volume, and a decrease in mean respiratory resistance over the tidal range in both groups. These results indicate that isoflurane does not cause an increase in bronchomotor tone, and may have a tendency to decrease it. This suggests that the previously reported increase of respiratory resistance during isoflurane anaesthesia resulted from a reduction in lung volume, rather than a change in bronchomotor tone.

Episodic postoperative oxygen desaturation: the value of added oxygen

Six patients were studied following general anaesthesia for cholecystectomy or hip replacement. Intravenous morphine was given for postoperative pain relief. Continuous measurements were made of breathing pattern and arterial oxygen saturation for a 12-hour period postoperatively. The effect of breathing either air or 28% oxygen for alternate 2-hour periods was examined. There was no significant effect of oxygen on the number of periods of central apnoea, obstructive apnoea or partial upper airways obstruction. The number of episodes of decreases in oxygen saturation to below 80%, associated with these breathing disturbances, was reduced from 59 to zero by the administration of oxygen. There was a gradual improvement in oxygenation whilst breathing air during the 12-hour postoperative period. The administration of oxygen had a beneficial effect on average arterial oxygen saturation.

Histochemical and morphometric changes in muscles of stroke patients

There is little information on the muscle fiber changes or the fiber type affected in supraspinal hemiplegia. Muscle biopsy specimens from 20 patients with stroke, obtained during orthopedic reconstruction, were examined by modern histochemistry. Atrophy was present in all of the muscles, affecting Type 1 fibers in 100% and Type 2 fibers in 95% of the patients. Type 2 atrophy was more severe than Type 1 atrophy. Group atrophy and fiber type grouping, present in 40%, seemed related to peripheral nerve or root damage. Hypertrophy of Type 1 fibers was present in 45%, associated with Type 2 hypertrophy in 15%. Although diffuse morphometric atrophic seemed not to correlate with the level of motor activity in this group of 20 patients, hypertrophy appeared related to activity. Hence, efforts to mobilize and rehabilitate stroke patients cannot prevent atrophy of some fibers, they seem to stimulate a hypertrophy not seen in inactive patients.

Pronounced, episodic oxygen desaturation in the postoperative period: its association with ventilatory pattern and analgesic regimen

The respiratory effects of two postoperative analgesic regimens were compared in two groups of 16 patients each, recovering from general anesthesia and major surgery. One group received a pain-relieving dose of iv morphine (mean, 18.1 mg), with the same dose repeated as a continuous intravenous infusion over the subsequent 24 h. The other group received regional anesthesia using bupivacaine. The patients were monitored for 16 h after surgery. The two analgesic regimens provided patients with comparable analgesia throughout the study period, but there were quite different respiratory effects in the two groups. Ten patients receiving morphine infusions had a total of 456 episodes of pronounced oxygen desaturation (SaO2 less than 80%). These occurred only while the patients were asleep, and all were associated with disturbances in ventilatory pattern, namely, obstructive apnea (144 episodes in eight patients), paradoxic breathing (275 episodes in six patients), and period of slow ventilatory rate (37 episodes in one patient). In contrast, in patients receiving regional anesthesia, oxygen saturation never decreased below 87%. Central apnea, obstructive apnea, and paradoxic breathing occurred more frequently in patients in the morphine group (12, 10, and 10 patients, respectively) than patients in the regional anesthesia group (4, 3, and 5 patients, respectively). The interaction of sleep and morphine analgesia produced disturbances in ventilatory pattern, causing profound oxygen destruction. These results suggest that postoperative pain relief using regional anaesthesia has a greater margin of safety in terms of respiratory side effects than does the continuous administration of opiates.

Evidence for altered vascular reactivity in sodium-sensitive young subjects with borderline hypertension

To assess mechanisms associated with the pressor effects of a high sodium diet in susceptible individuals, the hemodynamic and hormonal effects of sodium depletion and repletion were studied in 33 normal subjects and 30 subjects with borderline hypertension. The hypertensive group had significantly higher mean arterial pressure, weight, hematocrit, and upright plasma renin activity. Forearm hemodynamics were measured during periods of ad lib diet, 10 mEq, and 200 mEq sodium diet. The fall in forearm resistance during reactive hyperemia was inversely related to mean arterial pressure at rest (R = .400, p less than .005) and rose significantly in hypertensive subjects during salt depletion, 39 +/- 3.6 to 61 +/- 6.1 mmHg/ml/min/100 g (p less than .05). Sodium sensitivity in either normotensive or borderline hypertensive subjects was defined as an increase in mean blood pressure of more than 5% when sodium repleted. The individuals who were sodium sensitive had a higher forearm vascular resistance during sodium depletion than those who were sodium resistant, 67 +/- 10.5 versus 45 +/- 4.1 mm/ml/min/100 g (p less than .03). We conclude that young individuals with borderline hypertension already have alterations in vascular reactivity. This trait is shared by normotensive individuals whose blood pressure rises in response to sodium.

Measurement of systolic time intervals during exercise using inductive plethysmography

Measurement of systolic time intervals (STI) provides a noninvasive assessment of cardiac function in resting subjects. However, large motion artifacts often limit their application during exercise. To improve such measurements, we employed a new lightweight carotid arterial pulse transducer and minimized the artifacts by computerized signal averaging. The carotid pulse was recorded with an inductive plethysmographic transducer band (CIP) wrapped around the neck. STI derived from these measurements were compared to standard measurements from a funnel-shaped cup attached to the neck and connected to a pressure transducer (CUP) in 12 normal subjects at rest and with graded bicycle ergometry. To compare the techniques, CIP and CUP signals, together with the EKG and phonocardiogram, were connected separately to two microcomputer systems. The systems were triggered from the EKG and averaged the signals over 16 or 32 heart beats. Semi-automatic analysis of the averaged signals provided estimates of left ventricular ejection time (LVET), pre-ejection period (PEP) and electromechanical systole (QS2). Motion artifact levels of the unprocessed signals were similar with both CIP and CUP methods but were greatly reduced by signal averaging. All LVET values using CIP fell within 10% of CUP values. 85% of PEP values using CIP were within 20% of CUP values. Increasing exercise loads produced appropriate decreases in QS2, LVET, PEP and PEP/LVET consistent with increased myocardial contractility. The CIP proved comfortable to wear and did not require critical positioning as did the CUP. Measurement of STI complements exercise pulmonary testing with useful information of cardiac function.

Factors affecting balance and ambulation following stroke

Ninety consecutive patients with hemiplegic involvement following a single cerebrovascular accident were studied to assess the relative importance of factors affecting balance and ambulation. Only 50% of the patients achieved a community level of ambulation. Intact balance reactions correlated strongly with the ability to walk (r = 0.79). Balance was found to be dependent on limb control and proprioception. Age, sex, hemiplegic side, and structural factors did not correlate with function or recovery. The total score in each category of function was more highly correlated with balance and ambulation than were the individual scores.

Infections in the alcoholic

Serious infections appear to occur more frequently in alcoholic patients. However, whether this is due to the effects of alcohol per se or to the other frequent complications of alcoholism--nutritional deficiencies, cirrhosis, and poor hygiene--has not been determined. The host factors that may underlie an increased frequency of infection in alcoholics and the clinical infectious syndromes associated with alcoholism are described.

Ocular herpes simplex virus infection is diminished by depletion of B lymphocytes

Rabbit anti-mouse mu-chain serum was used to deplete specifically IgM-bearing B cells and B cell function in BALB/c mice. B cell-depleted and normal littermates were infected via the cornea with herpes simplex virus type 1 (HSV-1) at 4 to 5 wk of age. B cell-depleted mice had a reduced number of lymphocytes bearing surface immunoglobulin and a greatly reduced ability to produce antibody. Mortality was reduced from 89% in normal controls to 42% in B cell-depleted mice (p less than 0.001) and peak virus shedding from eyes was also reduced as much as 90% in the B cell-depleted mice (p less than or equal to 0.0005). These results support the hypothesis that a B cell function of normal mice somehow contributes directly or indirectly to the enhanced mortality of mice infected with HSV.

Ocular herpes simplex virus infection is diminished by depletion of B lymphocytes

Rabbit anti-mouse mu-chain serum was used to deplete specifically IgM-bearing B cells and B cell function in BALB/c mice. B cell-depleted and normal littermates were infected via the cornea with herpes simplex virus type 1 (HSV-1) at 4 to 5 wk of age. B cell-depleted mice had a reduced number of lymphocytes bearing surface immunoglobulin and a greatly reduced ability to produce antibody. Mortality was reduced from 89% in normal controls to 42% in B cell-depleted mice (p less than 0.001) and peak virus shedding from eyes was also reduced as much as 90% in the B cell-depleted mice (p less than or equal to 0.0005). These results support the hypothesis that a B cell function of normal mice somehow contributes directly or indirectly to the enhanced mortality of mice infected with HSV.

Effect of the antitussive glaucine on bronchomotor tone in man

In view of the observation that the antitussive agent glaucine prevents histamine-induced bronchoconstriction in guinea pigs we investigated this agent for a possible peripheral action in man, using a new method for measuring changes in bronchomotor tone. The forced airflow oscillation method was used to determine respiratory resistance (Rrs) over a range of lung volumes (VL) in seven healthy supine subjects. Computer analysis of the hyperbolic relationship between Rrs and VL was used to determine the asymptotic resistance and yield estimates of lower airways conductance (Glaw). Specific lower airways conductance (sGlaw) was expressed as the slope of the linear plot of Glaw against VL and is a sensitive index of bronchomotor tone. After baseline measurements of sGlaw subjects received placebo or 60 mg glaucine orally according to a double-blind crossover protocol. Histamine, 500 micrograms, was inhaled 45 minutes later. Measurements of sGlaw were repeated every 10 minutes for two hours. Although there was a trend towards bronchodilatation after glaucine administration (sGlaw = 130% of baseline) there was no significant difference from the effect of placebo (sGlaw = 89% of baseline). After inhalation of histamine sGlaw fell to 26% of baseline after both glaucine and placebo (p less than 0.01). In a further study three subjects received glaucine and placebo according to an identical protocol except that the histamine was omitted. Again the increase in sGlaw failed to achieve significance. Glaucine does not affect the bronchoconstrictor response to histamine in man and there is no convincing evidence of an effect on resting bronchomotor tone.

Enflurane anaesthesia causes graded changes in the brainstem and early cortical auditory evoked response in man

The effect of increasing end-tidal enflurane concentration on the auditory evoked response was studied in six patients. After a standard induction, anesthesia was maintained with 70% nitrous oxide in oxygen and the end-tidal enflurane concentration was increased gradually from 0 to 1% over a period of 30 min. The averaged auditory evoked response was derived from the electroencephalogram and measurements were made of the latencies and amplitudes of waves I, III, V, Pa and Nb within the auditory evoked response. The latencies of all waves and the interpeak latencies I to V and III to V showed significant linear increases and the amplitudes of Pa and Nb showed significant linear decreases with increasing end-tidal enflurane concentration. These results could not be explained by changes in deep body temperature or end-tidal carbon dioxide concentration. The study demonstrated a dose-related direct effect of enflurane on the brainstem and early cortical components of the auditory evoked response.

Effect of subanaesthetic concentrations of nitrous oxide on the regulation of ventilation in man

The pattern of ventilation was studied in eight healthy male volunteers breathing, in sequence, air and then two subanaesthetic concentrations of nitrous oxide (20% and 40%). The effect of these gas mixtures on the response to an added inspiratory resistance (3.88 kPa litre-1s-1) was examined. During unrestricted breathing of 40% nitrous oxide, there was a significant decrease (P less than 0.05) in inspiratory time (TI), a concomitant increase in the rate of ventilation and a significant decrease (P less than 0.05) in the end-tidal carbon dioxide tension (PE'CO2) compared with air breathing. For the first breath on load while breathing 40% nitrous oxide, there were significant decreases (P less than 0.05) in the responses for TI and tidal volume (VT) compared with the responses when breathing air. TI, VT, minute volume and PE'CO2 were similar for each gas mixture during steady state breathing against resistance. The increase in PE'CO2 when breathing 40% nitrous oxide against the resistance represented a significant (P less than 0.01) difference in response to the load compared with that breathing air. There was no significant change in these variables when breathing 20% nitrous oxide.