Direct and indirect causes of sex differences in mercury concentrations and parasitic infections in a marine bird

In many animal species, males and females differ in their levels of contaminants and/or parasitic infections. Most contaminants and gastro-intestinal parasites are obtained through prey ingestion, and thus the causes of sex differences in the distribution of these factors might follow similar pathways. We studied the northern common eider duck (Somateria molissima borealis) as an avian model, and used directed separation path analysis to explore the causes of sex differences in mercury (Hg) and gastro-intestinal helminths. Two trophically transmitted helminths were examined: a cestode (Lateriporus sp.) and an acanthocephalan (Polymorphus sp). We found that the number of Lateriporus sp. varied positively with stable isotope signature (as indicated by δ(15)N in eider breast muscle tissue), and negatively with crustaceans being present in the short term diet. We also found that Polymorphus sp. varied positively with eider tissue stable isotope signature. However, Polymorphus sp. varied negatively with sex indirectly through condition and liver mass. Similarly, Hg concentrations also varied negatively with sex indirectly through condition and liver mass, with both Polymorphus sp. intensity and Hg concentrations significantly higher in males. We found that model fit increased when a negative relationship between the two helminth species was included, suggesting a yet unknown causal mechanism linking these parasites. Our findings suggest that although Hg and gastro-intestinal parasites are both trophically transmitted through the eider's prey items, the factors that contribute towards bioaccumulation of these two burdens differ in source, likely caused by several different factors and may potentially influence each other.

Measurement of Whole-Body CO2 Production in Birds Using Real-Time Laser-Derived Measurements of Hydrogen (δ(2)H) and Oxygen (δ(18)O) Isotope Concentrations in Water Vapor from Breath

The doubly labeled water (DLW) method is commonly used to measure energy expenditure in free-living wildlife and humans. However, DLW studies involving animals typically require three blood samples, which can affect behavior and well-being. Moreover, measurement of H (δ(2)H) and O (δ(18)O) isotope concentrations in H2O derived from blood using conventional isotope ratio mass spectrometry is technically demanding, time-consuming, and often expensive. A novel technique that would avoid these constraints is the real-time measurement of δ(2)H and δ(18)O in the H2O vapor of exhaled breath using cavity ring-down (CRD) spectrometry, provided that δ(2)H and δ(18)O from body H2O and breath were well correlated. Here, we conducted a validation study with CRD spectrometry involving five zebra finches (Taeniopygia guttata), five brown-headed cowbirds (Molothrus ater), and five European starlings (Sturnus vulgaris), where we compared δ(2)H, δ(18)O, and rCO2 (rate of CO2 production) estimates from breath with those from blood. Isotope concentrations from blood were validated by comparing dilution-space estimates with measurements of total body water (TBW) obtained from quantitative magnetic resonance. Isotope dilution-space estimates from δ(2)H and δ(18)O values in the blood were similar to and strongly correlated with TBW measurements (R(2) = 0.99). The (2)H and (18)O (ppm) in breath and blood were also highly correlated (R(2) = 0.99 and 0.98, respectively); however, isotope concentrations in breath were always less enriched than those in blood and slightly higher than expected, given assumed fractionation values between blood and breath. Overall, rCO2 measurements from breath were strongly correlated with those from the blood (R(2) = 0.90). We suggest that this technique will find wide application in studies of animal and human energetics in the field and laboratory. We also provide suggestions for ways this technique could be further improved.

Small-dose selective spinal anaesthesia for short-duration outpatient gynaecological laparoscopy: recovery characteristics compared with propofol anaesthesia

A randomized controlled trial compared recovery characteristics after selective spinal anaesthesia (SSA) or propofol general anaesthesia (GA) for short-duration outpatient laparoscopic surgery. Forty women were randomized to receive either SSA (1% lidocaine 10 mg, sufentanil 10 microg and sterile water 1.8 ml) or GA (propofol and nitrous oxide 50% in oxygen). Compared with the GA group, times to leaving the operating room, performing a straight leg raise, performing deep knee-bends and achieving an Aldrete score >9 and the time in Phase II recovery were significantly shorter (P < 0.05) in the SSA group.

Selective spinal anesthesia for outpatient laparoscopy. I: characteristics of three hypobaric solutions

PURPOSE

To determine the characteristics and recovery profiles of three hypobaric spinal anesthetic solutions.

METHODS

Thirty outpatients undergoing outpatient laparoscopy were randomly assigned to receive spinal anesthesia with one of three small-dose solutions. Group I--20 mg lidocaine plus 25 microg fentanyl; Group II--20 mg lidocaine plus 10 microg sufentanil; Group III--10 mg lidocaine plus 10 microg sufentanil. Solutions were diluted to three ml with sterile water for injection. A 27-gauge Whitacre needle was inserted at L2-3 or L3-4 in the sitting position. Sensory and motor recovery were assessed with pinprick, proprioception, light touch and a modified Bromage scale.

RESULTS

Operating conditions were good to excellent in all three groups. The incidence of shoulder tip discomfort, pruritus and nausea was not significantly different between groups. Light touch was present in all three groups and proprioception was present in most patients during and after surgery. Group III patients had a more rapid recovery of pinprick analgesia and Group II patients had the slowest recovery of pinprick analgesia. Motor block recovery was comparable in the three groups. Eighty percent of patients in Groups III and I were able to perform 'deep knee bends' and 'straight leg raises' at the end of surgery.

CONCLUSION

For short duration laparoscopy, spinal 10 mg lidocaine with 1O microg sufentanil provided selective pin prick analgesia, with preserved touch, proprioception and limited motor block. Operating conditions were satisfactory and most patients were able to fulfill 'walk out' criteria at the end of surgery.

Selective spinal anesthesia for outpatient laparoscopy. IV: population pharmacodynamic modelling

PURPOSE

To apply a population pharmacodynamic model to small-dose hypobaric spinal anesthesia for outpatient laparoscopy.

METHODS

The level of spinal analgesia after spinal blockade with small-dose (20-25 mg) hypobaric lidocaine was assessed by means of pinprick in patients undergoing outpatient laparoscopy. In 57 patients, 385 measurements were available for analysis. We first modelled the data for each patient with a mixed-effects model described by Schnider (Model 1). The population mean parameters, inter-individual variance, and residual variance were estimated. Clinically important endpoints (time to reach T10 (onset), time to maximal level, duration and maximally attained level) of each patient were calculated based on the estimated time course of analgesia level for each patient. The model was used to predict the later data with respect to level of spinal analgesia of each patient from fits based on the observed data in the first 75 min.

RESULTS

The mean +/- SD onset time was 8.3 +/- 1.9 min, time to maximal level was 20.8 +/- 5.3 min, duration of effect was 37.9 +/- 13.1 min, and mean maximal level was T5. There was a good correlation (R2 = 0.90) between the observed levels of analgesia and those predicted from the model. Data from the first 75 min predicted the later observed data for each patient moderately well (R2 = 0.38).

CONCLUSION

A population pharmacodynamic model was applied to low-dose hypobaric lidocaine spinal anesthesia. Clinically important endpoints were determined and forecasting of later data with respect to level of spinal analgesia was attempted. Such an approach may be useful in the management of low-dose spinal anesthetic techniques in outpatients.

Selective spinal anesthesia for outpatient laparoscopy. II: epinephrine and spinal cord function

PURPOSE

To compare two small-dose solutions (with and without epinephrine) for spinal anesthesia during outpatient laparoscopy and to determine spinal cord function with these low-dose solutions.

METHOD

Twenty outpatients undergoing gynecological laparoscopy were randomly assigned to receive spinal anesthesia with one of two low dose solutions. Group LS-10 mg lidocaine plus 10 microg sufentanil; Group LSE-10 mg lidocaine plus 10 microg sufentanil plus epinephrine 50 microg. Solutions were diluted to three millilitres with sterile water for injection. A 27-gauge Whitacre needle was inserted at L2-3 or L3-4 in the sitting position. Operating conditions and spinal cord function (spinothalamic, dorsal column and motor) were assessed.

RESULTS

Operating conditions were good-excellent in both groups. The incidence of shoulder tip discomfort, pruritus and nausea, and the amount of supplementation with alfentanil and midazolam was not different between groups. Most patients in both groups had preserved dorsal column function and normal motor power on arrival in PACU and were able to satisfy 'walk out' criteria. Recovery of pinprick sensation and discharge times were not different. Mild pruritus (VAS score < or = 5) was present in both groups.

CONCLUSION

For short duration laparoscopy, addition of 50 microg epinephrine to a small dose of spinal 10 mg lidocaine with 10 microg sufentanil did not provide additional benefit in terms of intraoperative analgesia or operating conditions. Spinal cord function was preserved with small-dose techniques.

Selective spinal anesthesia for outpatient laparoscopy. V: pharmacoeconomic comparison vs general anesthesia

PURPOSE

To compare the cost and effectiveness of small-dose spinal anesthesia (SP) with general anesthesia (GA) for outpatient laparoscopy.

METHODS

A retrospective record analysis of 24 patients who received SP were compared with 28 patients who received GA in our Daycare centre. The costs of anesthesia and recovery were calculated, from an institutional perspective, using 1997 Canadian Dollar values. Effectiveness was measured in terms of time for anesthesia and recovery, and postoperative antiemetic and analgesic requirements.

RESULTS

Both groups were well matched for age, weight, duration and type of surgery. The mean total cost for the SP group of $53.45 +/- 10.40 was no different from that for the GA group of $48.92 +/- 10.25 (95% CI -10.3, 1.2). Time to administer anesthesia was longer in the SP group with a mean time of 18 +/- 8 min compared with 10 +/- 3 min in the GA group (CI -11.3, -4.7). Recovery time in the PACU was longer in the SP group 123 +/- 51 min compared with 94 +/- 48 min (CI -56.6,-1.4). Postoperative antiemetic requirements were similar: 8% in SP group vs 14% in GA group, whereas analgesic requirements were less in the SP group with 25% receiving analgesia compared with 75% in the GA group (P < 0.05).

CONCLUSION

The total cost of anesthesia and recovery using SP is similar to that for GA when used for outpatient laparoscopy. Spinal anesthesia was less effective than GA in time to administer anesthesia and in duration of recovery. Postoperative analgesic requirements were reduced using SP.

Selective spinal anesthesia for outpatient laparoscopy. III: sufentanil vs lidocaine-sufentanil

PURPOSE

The efficacy of low dose intrathecal lidocaine-sufentanil was compared with intrathecal sufentanil for short duration outpatient gynecological laparoscopy.

METHODS

Thirteen ASA I and II patients undergoing gynecological laparoscopy were studied in a randomized double-blind trial. Patients received either intrathecal 10 mg lidocaine plus 10 microg sufentanil (Group LS) or intrathecal 20 microg sufentanil (Group S), each diluted to 3 mL with sterile water through a 27g Whitacre needle in the sitting position. Sensory and motor recovery were assessed with pinprick and a modified Bromage scale.

RESULTS

One of seven Group LS patients and two of five Group S patients required conversion to general anesthesia for failed skin test with forceps. Two of the remaining three Group S patients felt sharpness with skin incision. The study was terminated early because of inadequate anesthesia in Group S. The small sample size (n = 9) made statistical analysis uninformative.

CONCLUSION

Intrathecal 20 microg sufentanil is unsuitable as a sole agent for gynecological laparoscopy.

Induction of labour: a continuous quality improvement and peer review program to improve the quality of care

This article describes a program developed to improve the process of planned induction of labour and to reduce the rates of inappropriate induction. The setting is a tertiary-care maternity hospital in urban Vancouver, BC, in which 7000 deliveries take place annually. Approximately 65% of these can be considered primary care; the remainder are secondary- or tertiary-level cases. Continuous quality improvement (CQI) methods were used by a multidisciplinary team, which included nursing staff, physicians, health records personnel and a CQI facilitator. Interventions included the development of a new induction-booking process, clear criteria for induction, feedback to caregivers about changes and a peer review system to oversee and maintain improvement. The overall induction rate for the institution decreased, and this change has been maintained.

alphavbeta3 and vitronectin expression by normal ovarian surface epithelial cells: role in cell adhesion and cell proliferation

The alphavbeta3 integrin and its ligand vitronectin are expressed by differentiated epithelial ovarian carcinomas and carcinoma cell lines in culture. Moreover, alphavbeta3/vitronectin interaction influences adhesion and migration of ovarian carcinoma cells in culture. For a better understanding of the behavior of these carcinomas, it appeared necessary to study the characteristics of their normal counterpart, the ovarian surface epithelium (OSE). The present study showed that normal cultured human OSE cells, like the carcinoma cells, have the ability to synthesize vitronectin. The vitronectin receptor, alphavbeta3 integrin, is also expressed by OSE cells and is localized in focal contacts close to paxillin, a focal contact-specific protein, and p125(FAK), a cytoskeletal and signaling molecule. This localization suggested an active participation of the integrin in the adhesion and/or proliferation of OSE cells. Indeed, the use of a blocking antibody demonstrated that alphav integrins promote OSE cell adhesion on vitronectin but not on fibronectin and that these integrins are required for maximal proliferative activity. The results suggest a role of the alphavbeta3/vitronectin system in normal OSE physiology and demonstrate that the expression of this system by well-differentiated ovarian carcinomas reflects the retention of normal cell properties.

Urinary myelin basic protein-like material in patients with multiple sclerosis during interferon beta-1b treatment

OBJECTIVES

To determine levels of urinary myelin basic protein-like material (MBPLM) in patients with multiple sclerosis (MS) openly treated with interferon beta-1b and to correlate these with clinical changes.

BACKGROUND

Levels of urinary MBPLM correlate with the presence of the progressive phase of MS and with the disease burden detected on T2-weighted, cranial magnetic resonance imaging. Measurement of urinary MBPLM level may be a feasible test for monitoring or predicting response to therapeutic measures.

DESIGN AND METHODS

In a prospective study at one site, 166 patients with MS (131 with relapsing-remitting [RR] and 35 with secondary progressive [SP] disease) were treated for a minimum of 1 year and up to 3 years with interferon beta-1b and underwent assessment for neurologic disability (Expanded Disability Status Scale and Scripps Neurological Rating Scale) and change in disease subtype. Urine samples were obtained at 1219 of 1378 clinic visits, and urinary MBPLM level was determined and related to creatinine level to adjust for renal function.

RESULTS

Statistical analysis using the general linear models procedure confirmed previous findings that the level of urinary MBPLM related to urinary creatinine level (MBPLM/creatinine) was higher (P<.001) in patients with SP than RR MS. Of the 131 patients with RR MS, SP disease developed in 13 during the observation period. Compared with those in the RR group, the RR to SP group had a higher level (P<.001) of urinary MBPLM and did not differ from the SP group.

CONCLUSIONS

The level of urinary MBPLM is higher in SP MS than RR MS but not in RR MS that converts to SP MS. Level of urinary MBPLM may permit the examination of treatment tested to prevent RR disease from becoming progressive.

A cross-reactive anti-myelin basic protein idiotope in cerebrospinal fluid cells in multiple sclerosis

We wanted to find evidence of antibody to myelin basic protein (MBP) in patients with MS by detecting their shared usage of immunoglobulin genes. As demonstrated by the idiotopes (i.d.) of murine monoclonal antibody to peptides of MBP, there is limited use of the variable (V) region immunoglobulin genes for the immune response in mice to this encephalitogenic protein. Cross-reactive Ids have been detected across different murine strains and shared by T and B cells. One cross-reactive Id, designated as 845D3 Id, is located on the V region of kappa light chains of two murine monoclonal antibodies, one to MBP peptide 80-89 and the other to MBP peptide acetyl 1-9. To examine the occurrence of 845D3 Id in MS, we used the V region of a light chain (VL) of one of the monoclonal antibodies to probe the VL genes expressed in B cells in CSF of 50 patients (31 MS and 19 non-MS). The VL genes expressed in B cells found in CSF were amplified by polymerase chain reaction using universal human V-region primers. The 845D3 Id probe detected the Id+ V region in the CSF of 14 of 31 MS patients, 1 of 9 patients with other neurologic diseases, and 1 of 10 non-neurologic patients. The gene product was more common in but not restricted to CSF with oligoclonal bands. The presence in CSF of MS patients of a cross-reactive Id to different MBP peptides is indicative of an immune response to this encephalitogenic myelin protein in a segment of MS patients. These findings are also evidence for limited usage of V-region Ig genes in the immune response of humans to MBP and the possible importance of an Id network for MBP in demyelinating disease.

Thalamic thought disorder: on being "a bit addled"

Humans can generate and maintain relatively coherent trains of thought in natural discourse. The neural mediation of this ability and the phenomenology of its breakdown are not well understood. We report a case of a woman with paramedian thalamic strokes involving the mammillothalamic tract, intralaminar nuclei, parts of the dorsomedial and ventral lateral nuclei bilaterally. She presented with a dense amnesia and confusion typical of the syndrome of bilateral paramedian thalamic infarcts. Her Tc-99m HMPAO brain SPECT scan showed decreased thalamic and basal ganglia blood flow. General diminution of cerebral blood flow and areas of further diminution in the right frontal, left temporal and left temporoparietal regions were also observed. Although her amnesia was characteristic of diencephalic amnesia, her most striking clinical feature was a bizarre, disconnected and at times incoherent speech output. Analysis of her speech revealed relatively preserved lexical and morpho-syntactic linguistic production. By contrast, analysis of the macrostructure of her discourse revealed frequent unpredictable topic shifts that were completely unconstrained by contextual factors. Many of her shifts were intrusions from previous topics. We interpret her severely disordered speech output as representing the surface manifestations of a thought disorder (rather than as a language disorder per se) characterized by an inability to maintain and appropriately shift themes that normally guide discourse. Median and intralaminar thalamic nuclei appear to be critical for the neurophysiologic regulation of thalamocortical and striatocortical circuits, which in turn may be critical for the functional regulation of contextually appropriate transitions of thought.

Immunological effects of an arginine side chain contaminating synthetically prepared peptides

The side chain, 4-methoxy-2,3,6-trimethylbenzenesulphonyl (Mtr), is a protective group coupled to arginine to mask the omega-nitrogen, in order to protect the guanidino function during peptide synthesis by the 9-fluorenylmethoxycarbonyl (Fmoc) procedure (Walker, 1994). This group is removed at the completion of peptide synthesis; however, the cleavage process can be incomplete. We have found that animals injected with a mixed population of pure, i.e. unmodified, and Mtr-containing MBP peptides have an immunodominant humoral response to the Mtr-bearing peptide. This response is dependent on the characteristics of the MBP peptide involved. For two MBP peptides, the Mtr-containing peptide had increased binding to antibody over pure peptide. For two other peptides, only the Mtr-containing peptide bound antibody while the unmodified peptide did not. In a separate system involving a polyclonal response to an unrelated peptide from beta2-microglobulin (beta2 m), the dominance of the Mtr group was also evident. These results provide further evidence that a small side chain on a single amino acid in a peptide can markedly alter the immunogenicity and antigenicity of that peptide for antibody reactivity. This evidence emphasizes the need for a critical awareness of each component of peptide synthesis and its potential to alter the immunoreactivity of the final product.

Small-dose hypobaric lidocaine-fentanyl spinal anesthesia for short duration outpatient laparoscopy. I. A randomized comparison with conventional dose hyperbaric lidocaine

A randomized, single-blind trial of two spinal anesthetic solutions for outpatient laparoscopy was conducted to compare intraoperative conditions and postoperative recovery. Thirty women (ASA physical status I and II) were assigned to one of two groups. Group I patients received a small-dose hypobaric solution of 1% lidocaine 25 mg made up to 3 mL by the addition of fentanyl 25 micrograms. Group II patients received a conventional-dose hyperbaric solution of 5% lidocaine 75 mg (in 7.5% dextrose) made up to 3 mL by the addition of 1.5 mL 10% dextrose. All patients received 500 mL of crystalloid preloading. Spinal anesthesia was performed at L2-3 or L3-4 with a 27-gauge Quincke point needle. Surgery commenced when the level of sensory anesthesia reached T-6. Intraoperative hypotension requiring treatment with ephedrine occurred in 54% of Group II patients but not in any Group I patients. Median (range) time for full motor recovery was 50 (0-95) min in Group I patients compared to 90 (50-120) min in Group II patients (P = 0.0005). Sensory recovery also occurred faster in Group I patients (100 +/- 22 min) compared with Group II patients (140 +/- 27 min, P = 0.0001). Postoperative headache occurred in 38% of all patients and 70% of these were postural in nature. Oral analgesia was the only treatment required. Spinal anesthesia did not result in a significant incidence of postoperative backache. On follow-up, 96% said they found spinal needle insertion acceptable, 93% found surgery comfortable, and 90% said they would request spinal anesthesia for laparoscopy in future. Overall, this study found spinal anesthesia for outpatient laparoscopy to have high patient acceptance and a comparable complication rate to other studies. The small-dose hypobaric lidocaine-fentanyl technique has advantages over conventional-dose hyperbaric lidocaine of no hypotension and faster recovery.

Small-dose hypobaric lidocaine-fentanyl spinal anesthesia for short duration outpatient laparoscopy. II. Optimal fentanyl dose

We performed a double-blind, controlled trial to determine the optimal dose of intrathecal fentanyl in small-dose hypobaric lidocaine spinal anesthesia for outpatient laparoscopy. Sixty-four gynecological patients were randomized into three groups, receiving 0, 10, or 25 micrograms fentanyl added to 20 mg lidocaine and sterile water (total 3 mL). Administration was with 27-gauge Whitacre needles and patients sat upright until the block was > T-8. One patient in the 0-microgram fentanyl group required general anesthesia 40 min after the start of surgery, leaving 21 patients per group. Three patients in each of the 0-microgram and 10-microgram fentanyl groups had mild discomfort with trocar insertion, or return of some sensation and felt discomfort or sutures toward the end of surgery. Shoulder-tip pain was less frequent in the 25-microgram than 0-microgram fentanyl group, 28% vs 67% (P < 0.0166). Intraoperative supplementation with alfentanil (+/- propofol) was needed less often in the 25-microgram than 0-microgram fentanyl group, 43% vs 76% (P = 0.028). Recovery of sensation took longer in the 25-microgram than in the 0-microgram and 10-microgram fentanyl groups, 101 +/- 21 vs 84 +/- 20 and 87 +/- 18 min (P < 0.05), although motor recovery and discharge times were the same. Postoperative analgesia was needed earlier in the 0-microgram than in the 25-microgram fentanyl group, median 54 (13-120) vs 87 (65-132) min (P < 0.05). Pruritus was the only side effect that occurred more often in the 10-microgram and 25-microgram groups than in the 0-microgram fentanyl group, 62% and 67% vs 14% (P < 0.0166). One patient required an epidural blood patch for postdural puncture headache. Based on these results, we concluded that 25 micrograms intrathecal fentanyl is required when 20 mg lidocaine is used for hypobaric spinal anesthesia (SA) to ensure reliable, durable anesthesia, reduce shoulder-tip pain, and minimize the need for intraoperative supplementation. This dose provides longer postoperative analgesia and does not increase side effects apart from pruritus. SA with small-dose hypobaric lidocaine-fentanyl was found to be a satisfactory technique for outpatient laparoscopy, although postdural puncture headache can occur in some patients.

Leukoencephalopathy associated with cobalamin deficiency

Patients with cobalamin deficiency may experience cognitive impairment or neuropsychiatric symptoms. Although abnormalities of central myelin are the presumed cause of these manifestations, there is a paucity of reports of white matter lesions as shown on neuroimaging studies, and the effects of cobalamin replacement on these lesions are not known. We report a man with subacute cognitive impairment associated with cobalamin deficiency and remarkable confluent white matter abnormalities on MRI, confirmed by biopsy. With cobalamin replacement, both his cognitive deficits and imaging abnormalities partially resolved. This case indicates that leukoencephalopathy, in the absence of anemia or myelopathy, should be added to the spectrum of disorders associated with cobalamin deficiency. Early detection and treatment may be associated with a greater potential for recovery.

The effect of test chart design and human factors on visual performance with night vision goggles

In an effort to increase flight safety, it is imperative to learn as much as possible about the man-goggle interrelationship. This study was undertaken to see if type of goggle or other covariates might affect visual acuity (VA). We tested the VA of 103 aircrew with both the AN/PVS-5 and Aviator's Night Vision Imaging System (ANVIS) goggles using a Snellen vision testing chart and the new Night Vision Goggle (NVG) Resolution (Grid Type) Chart. Average VA's using ANVIS (Snellen = 20/38, Grid = 20/45) were significantly better (p < 0.01) than VA's using AN/PVS-5 (Snellen = 20/54, Grid = 20/58). Snellen VA's were better on average than Grid VA's (p < 0.001). Neither age, gender, nor NVG experience affected average VA at the 0.05 level. Average VA was significantly better (p < 0.05) for non-spectacle wearers using ANVIS goggles and for non-smokers using AN/PVS-5 goggles. Visual acuity is better with ANVIS than with AN/PVS-5 goggles, and may be affected somewhat by wearing spectacles, and by smoking.

Otologic devices

The use of artificial devices to enhance audition is increasingly common. Although most complications of implanted devices, such as cochlear stimulators, occur in the immediate postoperative period, many later difficulties may come to the attention of the emergency medicine practitioner. This article reviews the common and uncommon complications of hearing aids, ossicular replacements, and implants. Advancements in this area will make such problems even more common in the future.

Rapid onset of severe heat illness: a case report

Aviators flying extended periods in hot environments are known to be at risk for heat-related illness. The risk when wearing chemical individual protective equipment (IPE) is increased even at relatively warm temperatures and light workloads. In this paper, we report the physiological responses of an aviator who had been flying a UH-1H helicopter up to 6 h/d clothed in full IPE on 6 consecutive days prior to the sudden onset of heat illness. His performance during the study was normal, and no clear physiological derangements were noted prior to his symptoms. The rapid evolution of his symptoms after voicing no complaints provides a graphic illustration of the difficult predictability and initial central nervous system effects of this condition.

Class II antigen expression in peripheral neuropathies

The expression of class II antigen was studied in sural nerve biopsies from patients with peripheral neuropathies. These included patients with chronic demyelinating polyradiculoneuropathy (CIDP), non-immune mediated neuropathies of diverse etiologies and controls without evidence of neuropathy. The major finding in CIDP was a marked increase in class II expression on Schwann cells. Endoneurial Schwann cell staining to the same degree as in CIDP was seen in diabetic symmetric proximal motor neuropathy, neuropathies associated with monoclonal gammopathies and hereditary sensory and autonomic neuropathy type 1. In the control nerves and the other non-immune mediated neuropathies class II expression was mainly restricted to endothelial and perineurial cells. Increased endoneurial expression of class II antigen was found to correlate with elevated cerebrospinal fluid (CSF) protein levels but not with other clinical variables or demyelination as defined by electrophysiologic criteria or teased fiber analysis. The increased expression of class II antigen on Schwann cells may be indicative of a breakdown in immunological tolerance but should not be used as a diagnostic marker for dysimmune neuropathies due to overlap with non-immune mediated neuropathies.

Viral hepatitis

Viral hepatitis is the most common serious contagious disease caused by viruses that attack the liver. Approximately 70,000 cases are reported to the Centers for Disease Control each year, representing only a fraction of U.S. cases. There are five types of viral hepatitis currently known: Hepatitis A--formerly called infectious hepatitis; Hepatitis B--formerly called serum hepatitis, and the most serious form; Hepatitis C--formerly called non-A, non-B hepatitis; Hepatitis D--formerly called delta hepatitis; Hepatitis E--formerly called enteric or epidemic non-A, non-B hepatitis. The following Open Forum, prepared by leading EMS experts, explores the differences among the types of hepatitis, signs and symptoms, and EMS implications.

A survey of U.S. Army aeromedical equipment

Medical equipment is necessary to support patients requiring air transportation, but it may not be compatible with the aviation environment. Aircraft systems may cause errors in the functioning of medical equipment, or that equipment may interfere with the aircraft. Medical equipment has been tested, primarily for fixed wing aircraft, to military standards by the U.S. Air Force. This study reports 1986 and 1987 surveys which document the use of such equipment on U.S. Army medical evacuation aircraft and compares items in current use to the U.S. Air Force's test results. Of the 115 different nonissue items reported in use, 32 have been formally evaluated, and 9 of those were judged unacceptable for use on aircraft. Only two items reported in the survey were tested inflight in helicopters. The remaining 83 items have not been tested. Helicopters have unique requirements, and the U.S. Army has begun a program to evaluate medical equipment for helicopter use.

Menstrual pattern change 1 year after sterilization: results of a controlled, prospective study

To determine if female sterilization is associated with adverse menstrual change, we compared prospectively collected menstrual data from women who underwent sterilization via bipolar cauterization, banding, and Pomeroy ligation with data from women whose husbands obtained a vasectomy and from women who were not planning sterilization. At first-year follow-up, sterilization via banding with Falope rings was not associated with adverse change. After excluding initially abnormal cases: (1) cauterization women were bleeding more heavily than all other groups excepting Pomeroy; (2) cauterization and Pomeroy women experienced more dysmenorrhea than women not planning sterilization; and (3) more cauterization and Pomeroy women (collapsed samples) developed abnormal length cycles than did the two control groups. There were no group differences regarding development of beneficial/neutral change (e.g., decreased dysmenorrhea). However, cauterization and Pomeroy groups experienced a significantly higher average number of adverse changes than did the other groups and were at significantly greater risk of developing one or more adverse changes than were women not planning sterilization. The only pattern of association among adverse menstrual changes occurred significantly more often in the cauterization and next in the Pomeroy groups.

Early diagnosis of basilar artery occlusion using magnetic resonance imaging

Three patients with a clinical diagnosis of pontine infarction probably due to basilar artery occlusion were studied with magnetic resonance imaging within 24 hours after onset or latest progression of symptoms. The earliest changes on magnetic resonance images were an absence of signal void in the basilar artery suggestive of severe reduction of blood flow or occlusion (flow-void phenomena). The presumed basilar artery thrombosis was best demonstrated as a linear structure isointense or hyperintense with the brainstem in the pontine cistern on T1-weighted parasagittal images and as either absence of flow-void phenomena or higher signal intensity at various levels corresponding to the course of the basilar artery on the axial T2-weighted images. Brainstem parenchymal changes characteristic of infarction were not obvious for at least 12 hours after onset or 90 minutes after latest progression of symptoms and were best shown by both axial and coronal T2-weighted images. Recognition of these magnetic resonance imaging findings may allow earlier diagnosis and treatment of acute ischemia in the vertebrobasilar system.

Response to immunosuppressive therapy in patients with hereditary motor and sensory neuropathy and associated dysimmune neuromuscular disorders

We encountered 2 patients with hereditary motor and sensory neuropathy (HMSN) type I who had marked weakness developing during several months superimposed on chronic peroneal muscular atrophy. Further studies disclosed a chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) in one patient and CIDP associated with polymyositis in the other. Both patients responded to prednisone and azathioprine with substantial improvement. Patients with HMSN who develop rapid progression of weakness should be evaluated for superimposed, potentially treatable dysimmune neuromuscular disorders.

Perforation of the ileum as a complication of suprapubic catheterization

Although suprapubic catheterization is a useful technique in managing the postoperative patient who requires prolonged urinary drainage, the potential exists for iatrogenic damage to the abdominal contents. Two cases of perforation of the distal ileum occurring during catheter placement after vaginal procedures are presented. Such complications may be kept at a minimum by adequate bladder distention, careful bladder palpation, placement of the patient in the Trendelenburg position before filling the bladder, and catheter insertion before closure of the surgical incision.

Ovarian carcinoma: management of stress in patients and physicians

A discussion of the management of ovarian cancer invariably involves the problems of death and dying faced by the patient, her family, and her physician. This paper attempts to deal with the general fears, anxieties, and problems of terminality, and also places attention on specific issues involved in living with the ongoing disease and its treatments. Focus is on the effects of the disease on the woman's self-image, on her family and relationships, on life outside the hospital, and on her relationship with her attending physician. Specific problems relating to the periods of (1) diagnosis, (2) operative management and treatment, and (3) terminality are discussed. Understanding the psychosocial realities of the patient provides the physician with added insights into methods to assist the patient in adaptation and coping with this ultimately fatal disease.

Outpatient breast biopsies on a gynecologic service

One hundred forty-six breast biopsies in 143 patients were done on outpatient basis, without general anesthesia, on a gynecologic service between 1975 and 1980. This procedure has advantages over in-hospital biopsy in terms of cost, time, reduced immediate risk, and patient acceptance. Greater long-term risk, if carcinoma is found, has not been substantiated. Gynecologists need this procedure as an adjunct to the management of benign breast conditions and should be trained to do it.

Complete duplication of the uterus and cervix with a unilaterally imperforate vagina

Complete duplication of the uterus and cervix with a unilaterally imperforate vagina must be suspected when a unilateral pelvic mass terminates in a purpuric bulge of the lateral vaginal wall in a young woman with severely progressive dysmenorrhea. Intravenous pyelography will reveal renal agenesis ipsilateral to the imperforate vagina. The prompt and accurate diagnosis of this unusual anomaly should lead to transvaginal drainage of the retained menstrual fluids prior to irreversible damage of the pelvic viscera from chronic cryptomenorrhea.

Surfactants, L/S ratio, amniotic fluid optical density and fetal pulmonary maturity

Optical density readings of amniotic fluids of 0.15 or greater at 650 nm have been noted to correlate with fetal pulmonary maturity. The amniotic fluid absorbance has been shown to be due not only to lecithin and sphingomyelin but also to other surfactants, including phosphatidyl glycerol and inositol. The addition of lecithin and sphingomyelin to previously centrifuged amniotic fluid (i.e., optical) density less than 0.001: L/S ratio, nondetectable) results in an increase in absorbance. At any simulated L/S ratio, the addition of phosphatidyl glycerol and/or phosphatidyl inositol results in a further increase in optical density. It is suggested that optical density readings represent more closely the surfactant composition of amniotic fluid than L/S ratios; therefore, it appears that optical density measurements are a better predictor of fetal pulmonary development than are L/S ratios.

Premature rupture of the membranes at term. A comparison of induced and spontaneous labors

Analysis of 150 patients at term (greater than 36 weeks) with premature rupture of the membranes (PROM) was made. In the group followed conservatively, 87.5% (98 of 112) began labor within 48 hours, and only 3.6% (4 of 112) had a latent period of greater than seven days. The incidence of cesarean section in patients with induced and spontaneous labors was compared in corrected groups. The induced group had a 39% (15 of 38) cesarean section rate as compared to 12% (11 of 91) in the spontaneous labor group (p = less than 0.01). None of the patients in the study showed signs of sepsis by central cultures, and only 12.7% (19 of 150) showed febrile morbidity. A conservative approach to term patients with PROM and an unfavorable cervix for induction seems to decrease the incidence of cesarean section.

A microtechnique for studying chemiluminescence response of phagocytes using whole blood and its application to the evaluation of phagocytes in pregnancy

Previous investigators have demonstrated that polymorphonuclear neutrophils exhibit intense chemiluminescence (CL) during phagocytosis and the CL response can be used to study the cellular and humoral aspects of the phagocytic process. A microtechnique that used 10 microliters of whole blood as a source of phagocytes was developed and used to measure the phagocytic CL response during pregnancy. Increased sensitivity was achieved by the use of a high concentration of luminol (0.5 mM), prepared by sonication, as a CL amplifier. The high intensity of CL produced with luminol permitted the use of a scintillation counter in the IN coincidence mode, avoiding the necessity of dark-adapting the counting vials and reagents and working under subdued red light. The CL response was dose dependent on the number of phagocytes and/or particles (polystyrene spherules, opsonized zymosan, and E coli). The CL response was decreased by inhibitors that prevent particle uptake (iodoacetate and fluoride), inhibitors that prevent free-radical production (sodium benzoate and superoxide dismutase), and by inhibitors that inactivate myeloperoxidase (cyanide and azide). Results suggested that the phagocytic CL response in our assay system was dependent on O2 activation followed by the activated O2 species reacting with myeloperoxidase and chloride. The new technique was used to demonstrate a progressive increase with gestation in the phagocytic CL response in pregnancy and a rapid decrease to normal values at 1 week postpartum.

Partial vaginal agenesis with a urinary-vaginal fistula

A patient with partial vaginal agenesis and a urinary-vaginal fistula is presented together with a review of the 12 cases reported previously. This unusual anomaly presents with cyclically recurrent hematuria; hypothetically, it results from failure of formation or canalization of the primitive vaginal plate together with partial persistence of the urogenital sinus. Surgical correction, ideally performed after puberty, requires resection of the fistula and mobilization of the apical vaginal segment for its anastomosis to the inferior vaginal pouch.

Removal of a presacral tumor via a Schuchardt incision

Presacral tumors have been traditionally approached either abdominally or via a transsacral incision. We describe a perineal approach to these tumors. A patient with a presacral benign cystic teratoma is described. The tumor was removed through a Schuchardt incision with no difficulties or complications. The vaginal approach should be considered for the removal of selected presacral tumors.