Ciliary neurotrophic factor-immunoreactivity in olfactory sensory neurons

Ciliary neurotrophic factor (CNTF) has been implicated in processes of neuroprotection, axonal regeneration and synaptogenesis in the lesioned CNS. In the olfactory system, which is characterized by particularly robust neuroplasticity throughout life, the concentration of CNTF is high even under physiological conditions. In the present study, the cellular localization of CNTF-immunoreactivity was studied in the rat and mouse olfactory epithelium. In both species, individual olfactory sensory neurons (ONs) displayed intense CNTF-immunoreactivity. The number of CNTF-ir ONs varied interindividually in rats and was lower in mice than in rats. In olfactory epithelia of mice expressing beta-galactosidase under control of the CNTF promoter, cells of the ON layer were immunoreactive for the reporter protein. CNTF-ir ONs were olfactory marker protein-positive and growth associated protein 43-negative. CNTF-ir ONs lacked apoptotic markers, and the number of specifically labeled ONs was apparently unchanged after light chemical lesioning of the epithelium, indicating that CNTF-immunoreactivity was not associated with ON death. Electron microscopy of CNTF-ir ON axons in innervated olfactory bulb glomeruli documented that they formed typical ON axonal synapses with target neurons. Three dimensional reconstructions of bulb pairs showed a striking similarity of the positions of glomeruli innervated by CNTF-ir ON axons in left and right bulbs of individual animals and interindividually. The number of innervated glomeruli differed interindividually in rats and was lower in mice than in rats. The results show that in rodents CNTF-immunoreactivity occurs in a subset of mature, functionally competent ONs. The localization of target glomeruli suggests that CNTF-immunoreactivity may be associated with the expression and/or activation of specific olfactory receptor proteins.

Ciliary neurotrophic factor in the olfactory bulb of rats and mice

Ciliary neurotrophic factor (CNTF) is primarily regarded as an astrocytic lesion factor, promoting neuronal survival and influencing plasticity processes in deafferented areas of the CNS. Postnatal loss of neurons in CNTF-deficient mice indicates a function of the factor also under physiological conditions. In the olfactory bulb, where neurogenesis, axo- and synaptogenesis continue throughout life, CNTF content is constitutively high. The cellular localization of CNTF in the rat olfactory bulb is not fully resolved, and species differences between mouse and rat are not yet characterized. In the present study, four different CNTF antibodies and double immunolabeling with specific markers for glial and neuronal cells were used to study the cellular localization of CNTF in rat and mouse olfactory bulb. Specificity of the detection was checked with tissue from CNTF-deficient mice, and investigations were complemented by immunolocalization of reporter protein in mice synthesizing beta-galactosidase under control of the CNTF promoter (CNTF lacZ-knock-in mice). In both species, CNTF localized to ensheathing cell nuclei, cell bodies and axon-enveloping processes. Additionally, individual axons of olfactory neurons were CNTF immunoreactive. Both CNTF protein content and immunoreaction intensity were lower in mice than in rats. Scattered lightly CNTF-reactive cells were found in the granular and external plexiform layers in rats. Some CNTF-positive cells were associated with immunoreactivity for the polysialylated form of the neural cell adhesion molecule, which is expressed by maturing interneurons derived from the rostral migratory stream. In CNTF lacZ-knock-in mice, beta-galactosidase reactivity was found in ensheathing cells of the olfactory nerve layer, and in cells of the glomerular, external plexiform and granular layers. The study proves that CNTF is localized in glial and neuronal structures in the rodent olfactory bulb. Results in mice provide a basis for investigations concerning the effects of a lack of the factor in CNTF-deficient mice.

Effect of supplemental pre-operative fluid on postoperative nausea and vomiting

In a prospective, double-blind, randomised controlled trial, we studied the effects of pre-operative fluid load on post-operative nausea and vomiting. Eighty patients attending for laparoscopic cholecystectomy or gynaecological surgery were randomly allocated to receive 2 ml.kg-1 (conservative) or 15 ml.kg-1 (supplemental) Hartmann's solution intravenously, shortly before induction of anaesthesia. During the operation, fluid management was identical in both groups. During the first post-operative 24 h, post-operative nausea and vomiting occurred in 29 patients (73%) in the conservative fluid group and nine patients (23%) in the supplemental fluid group (p = 0.01). Supplemental pre-operative fluid is an inexpensive and safe therapy for reducing post-operative nausea and vomiting.

Cardiotrophin-1, a muscle-derived cytokine, is required for the survival of subpopulations of developing motoneurons

Developing motoneurons require trophic support from their target, the skeletal muscle. Despite a large number of neurotrophic molecules with survival-promoting activity for isolated embryonic motoneurons, those factors that are required for motoneuron survival during development are still not known. Cytokines of the ciliary neurotrophic factor (CNTF)-leukemia inhibitory factor (LIF) family have been shown to play a role in motoneuron (MN) survival. Importantly, in mice lacking the LIFRbeta or the CNTFRalpha there is a significant loss of MNs during embryonic development. Because genetic deletion of either (or both) CNTF or LIF fails, by contrast, to perturb MN survival before birth, it was concluded that another ligand exists that is functionally inactivated in the receptor deleted mice, resulting in MN loss during development. One possible candidate for this ligand is the CNTF-LIF family member cardiotrophin-1 (CT-1). CT-1 is highly expressed in embryonic skeletal muscle, secreted by myotubes, and promotes the survival of cultured embryonic mouse and rat MNs. Here we show that ct-1 deficiency causes increased motoneuron cell death in spinal cord and brainstem nuclei of mice during a period between embryonic day 14 and the first postnatal week. Interestingly, no further loss was detectable during the subsequent postnatal period, and nerve lesion in young adult ct-1-deficient mice did not result in significant additional loss of motoneurons, as had been previously observed in mice lacking both CNTF and LIF. CT-1 is the first bona fide muscle-derived neurotrophic factor to be identified that is required for the survival of subgroups of developing motoneurons.

Specific function of B-Raf in mediating survival of embryonic motoneurons and sensory neurons

Embryonic sensory and motoneurons depend on neurotrophic factors for survival. Here we show that their survival requires B-Raf, which, in this function, cannot be substituted by C-Raf. Sensory and motoneurons from b-raf-deficient mice do not respond to neurotrophic factors for their survival. However, these primary neurons can be rescued by transfection of a b-raf expression plasmid. In contrast, c-raf-deficient neurons survive in response to neurotrophic factors, similarly to neurons from wild-type mice. This points to an essential and specific function of B-Raf in mediating survival of sensory and motoneurons during development.

Reg-2 is a motoneuron neurotrophic factor and a signalling intermediate in the CNTF survival pathway

Cytokines that are related to ciliary neurotrophic factor (CNTF) are physiologically important survival factors for motoneurons, but the mechanisms by which they prevent neuronal cell death remain unknown. Reg-2/PAP I (pancreatitis-associated protein I), referred to here as Reg-2, is a secreted protein whose expression in motoneurons during development is dependent on cytokines. Here we show that CNTF-related cytokines induce Reg-2 expression in cultured motoneurons. Purified Reg-2 can itself act as an autocrine/paracrine neurotrophic factor for a subpopulation of motoneurons, by stimulating a survival pathway involving phosphatidylinositol-3-kinase, Akt kinase and NF-kappaB. Blocking Reg-2 expression in motoneurons using Reg-2 antisense adenovirus specifically abrogates the survival effect of CNTF on cultured motoneurons, indicating that Reg-2 expression is a necessary step in the CNTF survival pathway. Reg-2 shows a unique pattern of expression in late embryonic spinal cord: it is progressively upregulated in individual motoneurons on a cell-by-cell basis, indicating that only a fraction of motoneurons in a given motor pool may be exposed to cytokines. Thus, Reg-2 is a neurotrophic factor for motoneurons, and is itself an obligatory intermediate in the survival signalling pathway of CNTF-related cytokines.

Differential regulation of adenosine A(1) and A(2A) receptors in serotonin transporter and monoamine oxidase A-deficient mice

The serotonin (5HT) transporter (5HTT) removes 5HT from the synaptic cleft and is thus critical to the control of serotonergic neurotransmission. Mice with a targeted inactivation of the 5HTT represent a novel and unique tool to study serotonergic system functioning. Because the release of 5HT is regulated by adenosine, we investigated 5HTT-deficient mice for possible adaptive changes of adenosine A(1) and A(2A) receptors. A(1) and A(2A) receptors were studied by means of quantitative autoradiography using the radioligands [3H]8-cyclopentyl-1,3-dipropylxanthine and [3H]CGS 21680, respectively. A comparison of 5HTT knockout versus control mice revealed upregulation of A(1) receptors in the dorsal raphe nucleus (DRN, +21%), but not in any of the serotonergic projection areas, and downregulation of A(2A) receptors in basal ganglia. The adaptive changes of A(1) and A(2A) receptors in 5HTT-deficient mice are likely to represent a compensatory neuroprotective effect mediated by the adenosinergic modulatory system. For comparison, these receptors were also studied in monoamine oxidase A (MAOA) knockout mice and in 5HTT/MAOA double knockout mice. 5HTT/MAOA double knockout mice showed adaptive changes of adenosine A(1) and A(2A) receptors similar to 5HTT knockout mice, while investigation of MAOA-deficient mice revealed an upregulation of A(2A) receptors, which may relate to a role of both MAOA and adenosine A(2A) receptors in anxiety.

The anti-apoptotic protein ITA is essential for NGF-mediated survival of embryonic chick neurons

The avian ITA is homologous to the baculoviral and mammalian inhibitor of apoptosis (IAP) proteins, which can prevent apoptosis by inhibition of specific caspases. We investigated the role of ITA in embryonic chick sympathetic and dorsal root ganglionic neurons, which depend on nerve growth factor (NGF) for their survival. Within 6 hours, NGF upregulated ITA protein production more than 25-fold in sensory and sympathetic neurons. Overexpression of ITA in primary neurons supported survival of these cells in the absence of NGF, and ita antisense constructs inhibited NGF-mediated survival. Thus the induction of ITA expression seems to be an essential signaling event for survival of sympathetic and dorsal root ganglionic sensory neurons in response to NGF.

Comparative analysis of motoneuron loss and functional deficits in PMN mice: implications for human motoneuron disease

We have investigated the correlation between functional and morphological deficits in PMN mice, an animal model of human motoneuron disease. Electrophysiologic investigations showed first abnormalities, i.e. reduction of M-response amplitudes, already at postnatal d 13 when the disease was not yet phenotypically apparent, and when motoneuron and motor axon numbers were still normal. After d 27, a loss of more than 30% of motoneuron axons and cell bodies was detectable in the phrenic nerve and facial nucleus, respectively. At that stage, PMN mice showed severe functional and electrophysiological deficits. At later stages of the disease when still more than 50% of motor axons and at least 60% of motoneuron cell bodies were present, the distal compound muscle action potential amplitude decreased by more than 95% in small foot muscles after sciatic nerve stimulation. We conclude that functional deficits precede structural deficits in this animal model of human motoneuron disease. Our findings are in agreement with the concept of the 'sick motoneuron' in this animal model of motoneuron disease rather than the idea of progressive loss of motoneurons resulting in disease only after a significant number of motoneurons has degenerated.

Mechanical and excitotoxic lesion of motoneurons: effects of neurotrophins and ciliary neurotrophic factor on survival and regeneration

Mechanical lesion of peripheral nerves leads to extensive death of corresponding motoneurons in newborn rodents. The extent of cell death can be significantly reduced by neurotrophic factors. These molecules are produced by glial and neuronal cells and play an important role in supporting survival and regeneration of various neuronal populations in the central nervous system, in particular after mechanical, excitotoxic and ischemic insults. In addition, factors such as ciliary neurotrophic factor and neurotrophin-3 influence glial cell proliferation and survival. We have investigated the role of neurotrophic factors on motoneurons, both in cell culture and after axotomy in vivo. Moreover, the role of excitatory neurotransmission in modulating dendritic architecture of these cells was analyzed. Our data suggest that motoneurons are a suitable model for investigating the complex functional and morphological changes after brain lesion and for the identification of new therapeutic strategies to influence survival and functional recovery under such circumstances.

The role of p75NTR in modulating neurotrophin survival effects in developing motoneurons

Neurotrophins exert their biological functions on neuronal cells through two types of receptors, the trk tyrosine kinases and the low-affinity neurotrophin receptor (p75NTR), which can bind all neurotrophins with similar affinity. The p75NTR is highly expressed in developing motoneurons and in adult motoneurons after axotomy, suggestive of a physiological role in mediating neurotrophin responses under such conditions. In order to characterize this specific function of p75NTR, we have tested the effects of nerve growth factor (NGF) on embryonic motoneurons from control and p75NTR-deficient mice. NGF antagonizes brain-derived neurotrophic factor (BDNF)- and neurotrophin-3 (NT-3)-mediated survival in control but not p75NTR-deficient motoneurons. Survival of cultured motoneurons in the presence of 0.5 ng/mL of either ciliary neurotrophic factor (CNTF) or glial-derived neurotrophic factor (GDNF) was not reduced by 20 ng/mL NGF. Dose-response investigations revealed that five times higher concentrations of BDNF are required for half-maximal survival of p75NTR-deficient motoneurons in comparison to motoneurons from wild-type controls. After facial nerve lesion in newborn wild-type mice, local administration of NGF reduced survival of corresponding motoneurons to less than 2% compared to the unlesioned control side. In p75NTR-deficient mice, the same treatment did not enhance facial motoneuron death on the lesioned side. In the facial nucleus of 1-week-old p75NTR -/- mice, a significant reduction of motoneurons was observed at the unlesioned side in comparison to p75NTR +/+ mice. The observation that motoneuron cell numbers are reduced in the facial nucleus of newborn p75NTR-deficient mice suggests that p75NTR might not function as a physiological cell death receptor in developing motoneurons.

Intrathecal sufentanil (5 vs. 10 microg) for labor analgesia: efficacy and side effects

BACKGROUND AND OBJECTIVES

Despite growing popularity, there are few studies examining the relative efficacy of different doses of intrathecal sufentanil for labor analgesia. This prospective, randomized, double-blind study compared the efficacy and side effects of 5 and 10 microg intrathecal sufentanil.

METHODS

Sixty-three healthy, laboring, term parturients < or =5 cm cervical dilation participated in this study. In a randomized, double-blind fashion, patients received 5 or 10 microg intrathecal sufentanil as part of a combined spinal epidural technique. Patients rated pain, itching, nausea, and sedation on verbal analog scales before and every 10 minutes after drug injection. We also recorded maternal blood pressure and peripheral oxygen saturation before and every 10 minutes after drug injection. Before and 30 and 60 minutes after drug injection, we measured maternal end-tidal CO2.

RESULTS

Both doses of sufentanil provided adequate analgesia. Although 10 microg sufentanil produced slightly more profound analgesia, the duration of pain relief did not differ between the two groups. Both drug doses were associated with significant increases in itching and end-tidal CO2. The 10-microg dose was associated with more sedation and a greater decrease in SaO2.

CONCLUSIONS

Both 5 and 10 microg intrathecal sufentanil provided adequate labor analgesia. Both doses were associated with measurable spinal (itching) and supraspinal (sedation, respiratory depression) side effects.

Endogenous ciliary neurotrophic factor is a lesion factor for axotomized motoneurons in adult mice

Ciliary neurotrophic factor (CNTF) is an abundant cytosolic molecule in myelinating Schwann cells of adult rodents. In newborn animals in which CNTF is not yet expressed, exogenous CNTF that is locally administered very effectively protects motoneurons from degeneration by axotomy. To evaluate whether endogenous CNTF, released after nerve injury from the cytosol of Schwann cells, supports motoneuron survival, we transected the facial nerve in 4-week-old pmn mice. In this mouse mutant a rapidly progressing degenerative disease of motoneurons starts by the third postnatal week at the hindlimbs and progresses to the anterior parts of the body, leading to death by the seventh to eighth week. Apoptotic death of motoneurons can be observed during this period, as revealed by TUNEL staining. In 6-week-old unlesioned pmn mice approximately 40% of facial motoneurons have degenerated. Facial nerve lesion dramatically increased the number of surviving motoneurons in pmn mice. This protective effect was absent in pmn mice lacking endogenous CNTF. Quantitative analysis of leukemia inhibitory factor (LIF) mRNA expression revealed that the dramatic upregulation seen in wild-type mice after peripheral nerve lesion did not occur in pmn mice. Therefore, endogenous LIF cannot compensate for the lack of CNTF in pmn crossbred with CNTF knock-out mice. Thus, endogenous CNTF released from lesioned Schwann cells supports the survival of axotomized motoneurons under conditions in which motoneurons are in the process of rapid degeneration.

Patient-controlled epidural analgesia: interactions between nalbuphine and hydromorphone

Epidural opioid analgesia can offer advantages over intravenous administration, however, opioid-related side effects are common after epidural administration. We studied the effect of adding nalbuphine (NB), an opioid agonist-antagonist, to hydromorphone (HM) for patient-controlled epidural analgesia (PCEA) in 78 healthy women after elective cesarean delivery. Patients were randomly assigned to one of four treatment groups. The control group received preservative-free HM (Dilaudid) alone, 0.075 mg/mL, while the three study groups received HM, 0.075 mg/mL, containing preservative-free NB (Nubain) 0.02, 0.04, or 0.08 mg/mL. Intraoperatively, all patients received epidural bupivacaine 0.5%. Postoperatively, a patient-controlled anesthesia (PCA) device was connected to the epidural catheter and programmed to deliver a 3-mL loading dose of the analgesic solution. Subsequently, patients could self-administer 2 mL bolus doses on demand with a 30-min lockout interval. Patients were encouraged to ambulate approximately 8 h after surgery, and PCEA therapy was discontinued when a clear liquid diet was tolerated. Visual analog scale scores were used to assess pain at 8-h intervals while using PCEA therapy. Although the overall incidences of nausea (19%-35%) and pruritus (32%-62%) were similar in all four groups, the addition of NB decreased the need for bladder catheterization. The highest NB concentration resulted in increased PCA demands during the 32-h study period. In conclusion, the combination of HM 0.075 mg/mL and NB 0.04 mg/mL resulted in lower nausea scores and a decreased incidence of urinary retention compared with HM alone, without increasing the opioid analgesic requirement.

Ciliary Neurotrophic Factor Enhances the Rate of Oligodendrocyte Generation

Although ciliary neurotrophic factor (CNTF) is a potent survival factor for many types of neurons and glial cells in vitro, there is currently no evidence that it participates in normal development. Here we show that CNTF greatly enhances the rate of oligodendrocyte generation. Proliferation of oligodendrocyte precursor cells purified from rodent optic nerves and cultured in platelet-derived growth factor-containing medium is significantly increased by CNTF. Similarly, the number of proliferating oligodendrocyte precursor cells in developing optic nerves of transgenic mice lacking CNTF is decreased by up to threefold and the number of oligodendrocytes is transiently decreased; proliferation is restored to normal by the delivery of exogenous CNTF into the developing optic nerve. Both oligodendrocyte number and myelination ultimately attain wild-type values in CNTF-deficient adult mice, indicating that CNTF is not necessary for either oligodendrocyte differentiation or myelination, although it normally accelerates oligodendrocyte development by enhancing the proliferation of oligodendrocyte precursor cells.

Inactivation of bcl-2 results in progressive degeneration of motoneurons, sympathetic and sensory neurons during early postnatal development

Bcl-2 is a major regulator of programmed cell death, a critical process in shaping the developing nervous system. To assess whether Bcl-2 is involved in regulating neuronal survival and in mediating the neuroprotective action of neurotrophic factors, we generated Bcl-2-deficient mice. At birth, the number of facial motoneurons, sensory, and sympathetic neurons was not significantly changed, and axotomy-induced degeneration of facial motoneurons could still be prevented by brain-derived neurotrophic factor (BDNF) or ciliary neurotrophic factor (CNTF). Interestingly, substantial degeneration of motoneurons, sensory, and sympathetic neurons occurred after the physiological cell death period. Accordingly, Bcl-2 is not a permissive factor for the action of neurotrophic factors, and although it does not influence prenatal neuronal survival, it is crucial for the maintenance of specific populations of neurons during the early postnatal period.

The response of motoneurons to neurotrophins

The ongoing search for neurotrophic factors for motoneurons has led to the identification of a number of molecules which regulate motoneuron survival and function. Among these factors, the neurotrophins brain derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3) and NT-4/5 but not nerve growth factor (NGF), can prevent embryonic and postnatal motoneuron cell death in a variety of experimental paradigms. Analysis of expression of p75, trkB and trkC-components of the neurotrophin receptors-supports a potential physiological role for these factors as muscle- and glial-derived trophic factors for motoneurons. However, the survival of motoneurons during embryonic development is not reduced in the absence of BDNF, NT-3 or NT-4, as revealed by gene knockout experiments. This points to the involvement of additional trophic factors in the regulation of embryonic and postnatal motoneuron survival. The purpose of this review is to bring together the often prophetic observations from earlier studies-prior to the identification and characterization of these neurotrophins-with more recent results.

Cryptic physiological trophic support of motoneurons by LIF revealed by double gene targeting of CNTF and LIF

BACKGROUND

The survival and differentiation of motoneurons during embryonic development, and the maintenance of their function in the postnatal phase, are regulated by a great variety of neurotrophic molecules which mediate their effects through different receptor systems. The multifactorial support of motoneurons represents a system of high security, because the inactivation of individual ligands has either no detectable, or relatively small, atrophic or degenerative effect on motoneurons.

RESULTS

Leukaemia inhibitory factor (LIF) has been demonstrated to support motoneuron survival in vitro and in vivo under different experimental conditions. However, when LIF was inactivated by gene targeting, there were no apparent changes in the number and structure of motoneurons and no impairment of their function. The slowly appearing, relatively mild degenerating effects in motoneurons that resulted from ciliary neurotrophic factor (CNTF) gene targeting were substantially potentiated by simultaneous inactivation of the LIF gene, however. Thus, in mice deficient in LIF and CNTF, the degenerative changes in motoneurons were more extensive and appeared earlier. These changes were also functionally reflected by a marked reduction in grip strength.

CONCLUSIONS

Degenerative disorders of the nervous system, in particular those of motoneurons, may be based on multifactorial inherited and/or acquired defects which individually do not result in degenerative disorders, but which become apparent when additional (cryptic) inherited disturbances or sub-threshold concentrations of noxious factors come into play. Accordingly, the inherited inactivation of the CNTF gene in a high proportion of the Japanese population may represent a predisposing factor for degenerative disorders of motoneurons.

Ciliary neurotrophic factor

Ciliary neurotrophic factor (CNTF) was first identified and partially purified from embryonic chick eye tissues. Subsequently, it was shown that CNTF is also present in large amounts in sciatic nerves of adult rats and rabbits, which led to its final purification and cloning. CNTF is not secreted by the classical secretory pathway involving the endoplasmatic reticulum and Golgi complex, but can be detected in high quantities within the cytoplasm of myelinating Schwann cells and astrocytes using immunohistochemistry. CNTF supports survival and/or differentiation of a variety of neuronal cell types including sensory, sympathetic, and motoneurons. Also, nonneuronal cells, such as oligodendrocytes, microglial cells, liver cells, and skeletal muscle cells, respond to exogenously administered CNTF, both in vitro and in vivo. During development, expression of CNTF is very low, if indeed it is expressed at all, and the phenotype of mice lacking endogenous CNTF after inactivation of the CNTF gene by homologous recombination suggests that CNTF does not play a crucial role for responsive cells during embryonic development. However, motoneurons are lost postnatally in mice lacking endogenous CNTF, suggesting that CNTF acts physiologically on the maintenance of these cells. The ability of exogenous CNTF to protect against motoneuron loss following lesion or in other animal models indicates that CNTF might be useful in the treatment of human motoneuron disorders, provided appropriate means of administration can be found.

Use of ketorolac after lower abdominal surgery. Effect on analgesic requirement and surgical outcome

BACKGROUND

Ketorolac is a nonsteroidal antiinflammatory agent with opioid-sparing properties. The effect of ketorolac on postoperative opioid analgesic requirement and surgical outcome was evaluated in 198 women after abdominal hysterectomy procedures using a double-blind protocol design.

METHODS

Patients were randomly assigned to receive either 60 mg intravenous (2 ml) ketorolac, followed by 30 mg intravenously (in saline 20 ml) over 30 min every 6 h, or 2 ml intravenous saline, followed by saline 20 ml intravenously over 30 min every 6 h, for up to 72 h. The postoperative opioid analgesic requirement was assessed using a patient-controlled analgesia (PCA) device to self administer either morphine or meperidine. The authors also evaluated pain, sedation (or drowsiness), fatigue, quality of sleep, and postoperative side effects at 2-8-h intervals for up to 72 h after surgery.

RESULTS

Ketorolac decreased the PCA opioid usage on the night of operation and during the first postoperative day. Ketorolac also improved the quality of sleep during the first night after surgery. Although ketorolac- (vs. saline-) treated patients had a significantly shorter time to passage of bowel gas (50 +/- 24 h vs. 61 +/- 25 h), there were no clinically significant differences in the times to oral intake, unassisted ambulation, or hospital discharge. There were also no differences in the overall incidence of side effects in the ketorolac- (vs. saline-) treated patients. However, the use of ketorolac with opioid PCA was associated with a reduced need for antiemetic therapy on the postsurgical ward.

CONCLUSIONS

The authors conclude that the opioid-sparing effects of ketorolac contributed few clinically significant advantages after abdominal hysterectomy procedures.

Disruption of the CNTF gene results in motor neuron degeneration

CNTF is a cytosolic molecule expressed postnatally in myelinating Schwann cells and in a subpopulation of astrocytes. Although CNTF administration prevents lesion-mediated and genetically determined motor neuron degeneration, its physiological function remained elusive. Here it is reported that abolition of CNTF gene expression by homologous recombination results in a progressive atrophy and loss of motor neurons in adult mice, which is functionally reflected by a small but significant reduction in muscle strength.

Brain-derived neurotrophic factor prevents the death of motoneurons in newborn rats after nerve section

Motoneurons innervating the skeletal musculature were among the first neurons shown to require the presence of their target cells to develop appropriately. But the characterization of molecules allowing motoneuron survival has been difficult. Ciliary neurotrophic factor prevents the death of motoneurons, but its gene is not expressed during development. Although the presence of a neurotrophin receptor on developing motoneurons has suggested a role for neurotrophins, none could be shown to promote motoneuron survival in vitro. We report here that brain-derived neurotrophic factor can prevent the death of axotomized motoneurons in newborn rats, suggesting a role for this neurotrophin for motoneuron survival in vivo.

Effects of a nighttime opioid infusion with PCA therapy on patient comfort and analgesic requirements after abdominal hysterectomy

Since pain during the early postoperative period can disrupt a patient's normal sleep pattern, we investigated the influence of a nighttime "basal" infusion of morphine on patient comfort, ability to sleep at night, restfulness, and analgesic requirements following elective abdominal hysterectomy. One hundred fifty-six adult women were randomly assigned to receive either patient-controlled analgesia (PCA) alone or PCA supplemented with a nighttime infusion of morphine 1.0 mg.h-1. The infusion was started in the postanesthesia care unit and continued until the morning after surgery. Subsequently, the infusion was used only during the nighttime hours (10 PM-8 AM). Patients in both treatment groups were able to self-administer supplemental bolus doses of morphine, 2 mg intravenously, as needed during the 72-h study period. The use of a nighttime morphine infusion did not significantly improve the patient's ability to sleep or to rest comfortably at night. Only 8% and 7% of patients in the control and infusion groups, respectively, found it inconvenient to self-administer bolus doses at night. In addition, the number of patient demands and supplemental bolus doses, opioid usage, and recovery parameters were similar in the two treatment groups. The use of a basal infusion resulted in six programming errors, and three patients required discontinuation of the infusion because of hemoglobin oxygen desaturation (i.e., SpO2 less than 85% for greater than 5 min). We concluded that the routine use of a continuous nighttime opioid infusion in combination with a standard PCA regimen failed to improve the management of postoperative pain, sleep patterns, or recovery profiles compared to PCA alone after abdominal hysterectomy.

Patient-controlled analgesia. Does a concurrent opioid infusion improve pain management after surgery?

OBJECTIVE

--To assess the influence of a continuous (basal) morphine infusion as part of a patient-controlled analgesia (PCA) system on the postoperative analgesic requirement and on recovery parameters following abdominal hysterectomy.

DESIGN

--Single-center, randomized, controlled protocol.

SETTING

--University medical center.

PARTICIPANTS

--A total of 230 adult women were randomly assigned to receive no morphine infusion (control group) or a continuous 0.5-, 1.0-, or 2.0-mg/h morphine infusion. Each patient was able to self-administer supplemental intravenous bolus doses of morphine (1 to 2 mg) using a PCA infuser.

MAIN OUTCOME MEASURES

--Use of the PCA device, opioid-related side effects, recovery times, and the patients' assessment of pain and sedation on linear visual analog scales were recorded during the 72-hour study period. Follow-up questionnaires were completed by the patients and their health care professionals to assess the overall adequacy of PCA therapy.

RESULTS

--Patients who received the 2-mg/h morphine infusions received significantly more opioid medication 9 to 72 hours after their operation than those who received no infusion (control group). The presence of a continuous morphine infusion of 0.5 to 2 mg/h did not significantly decrease the number of patient demands or supplemental bolus doses administered compared with the control group. Overall, 168 (84%) of the 199 patients who completed the 72-hour study were able to achieve adequate analgesia without requiring changes in the PCA regimen or experiencing major side effects. Recovery times and outcome variables were similar in all four groups.

CONCLUSION

--The routine use of a continuous opioid infusion in combination with a standard PCA regimen does not improve pain management compared with PCA alone after abdominal hysterectomy.

Fulminant hepatic failure after repeated exposure to isoflurane anesthesia: a case report

A previously healthy but obese 26-yr-old woman was diagnosed as having hepatic dysfunction 17 days after the third of three consecutive exposures to isoflurane anesthesia for paranasal sinus surgery. Serum laboratory findings included elevated aminotransferases and bilirubin. Radiographical evaluations showed no evidence of extrahepatic disease. Serological studies were negative for acute viral infections, and serum copper was normal. The patient's condition deteriorated over the ensuing 17 days, with hyperreflexia, hypoglycemia and a rapid fall in serum aminotransferases with a concomitant rise in bilirubin level and prothrombin time despite maximal medical support. The liver volume as shown by computed tomography fell from 1,290 cm3 to 680 cm3 over 6 days. The patient underwent successful orthotopic liver transplantation 25 days after onset of symptoms. Histopathological examination of the resected liver showed submassive and massive necrosis, with a few foci of microvesicular steatosis and ultrastructural evidence of mitochondrial abnormalities. Although we found insufficient evidence to prove that this case was caused by isoflurane anesthesia, the clinical course and histopathological findings are similar to those in hepatic injury caused by halothane anesthesia. Therefore we report this as a possible case of fulminant hepatic failure resulting from isoflurane anesthesia.

Selective shunting during carotid endarterectomy based on two-channel computerized electroencephalographic/compressed spectral array analysis

The reliability of selective shunting based on computerized electroencephalographic (EEG) monitoring has not been addressed. In this study, 103 carotid endarterectomies were performed with selective shunting based on a two-channel computerized EEG monitor that processed the on-line, raw electroencephalogram (EEG) to produce a compressed spectral array (CSA). Ischemic EEG events were identified by amplitude attenuation of the raw EEG and/or loss of high-frequency activity on the CSA. Fourteen patients (13.6%) received a bypass shunt, and postoperative neurological examinations showed 97 patients (94.2%) to be intact. A correlation between total (cumulative) ischemic EEG time and the postoperative neurological exam was demonstrated (P less than 0.0001). Six postoperative deficits (5.8%) occurred, five in patients whose computerized EEGs demonstrated an ischemic EEG event late during carotid clamping, when it was no longer possible to place a shunt. The sixth deficit was found in a patient whose EEG did not demonstrate any patient whose EEG did not demonstrate any signs of cerebral ischemia. Five of these six new deficits resolved within 12 hours, and only one persisted for 72 hours, when the patient died of a pulmonary embolism (cerebral infarction and mortality rate of 1%). These results appear to demonstrate that two-channel monitoring of both the CSA and the unprocessed (raw) EEG simultaneously can be used as a reliable indicator of whether a bypass shunt is required during carotid cross-clamping in all patients, regardless of their preoperative neurological history or angiographic findings.

A comparison of three techniques of palatorrhaphy: early speech results

Sixty-two patients with cleft lip and palate or cleft palate were randomly assigned an operative technique for primary palatorrhaphy: V-Y pushback, Langenbeck, or Langenbeck with pharyngeal flap. Early speech results were evaluated in 52 patients. There were no differences among the treatment groups in late complications, hearing, middle ear disease, velopharyngeal competence, or need for speech therapy, speech bulbs, or secondary pharyngeal flaps. As previously reported, the in-hospital morbidity in these patients was greater with V-Y pushback (more blood transfusions) and Langenbeck plus pharyngeal flap (more upper airway obstruction) palatorrhaphies than with the Langenbeck procedure. The addition of a pharyngeal flap to primary palatorrhaphy seems unnecessary in at least 75% of patients. Therefore, we currently recommend the Langenbeck palatorrhaphy for primary cleft palate repair, although further longitudinal studies of these patients are needed to assess later speech results and maxillary growth.

Severe epistaxis in facial fractures

The incidence of epistaxis in 312 patients with facial fractures over a 5-year period is reviewed, finding the incidence of epistaxis to be 4 percent in all facial fractures and 11 percent (12 of 108) in midface fractures. Six of these required treatment with packing or transfusion, and two required surgery to control the epistaxis. The only other series reviewing epistaxis in facial fractures reported a similar incidence.

A randomized comparison of triangular and rotation-advancement unilateral cleft lip repairs

We prospectively and randomly compared triangular and rotation-advancement unilateral cleft lip repairs in 35 patients. The most significant difference between the two repairs noted in this series was a greater frequency of hypertrophic scars following rotation-advancement repairs. The overall appearance of the lip and nose postoperatively was the same in both groups.

Decreased collagenase production by regional fibroblasts cultured from skin of a patient with connective tissue nevi of the collagen type

A 10-yr-old female presented with cerebriform tumors covering the plantar surfaces of both feet. Histologically, the lesions consisted of thick collagen fibers and the content of collagen per surface area of skin was increased about 8-fold. Examination of the collagen by SDS-polyacrylamide gel electrophoresis, after limited pepsin proteolysis, showed that the lesions consisted almost exclusively of type I collagen, the predominant collagen type in human skin. Thus, a diagnosis of connective tissue nevi of the collagen type was made. Fibroblast cultures were established from the affected and normal-appearing areas of the skin, and examined for the rate of collagen synthesis, production of collagenase and growth kinetics of the cells. Cell cultures derived from the lesion and from control skin synthesized procollagen at the same rate and in a normal type I/type III procollagen ratio. However, the production of enzymatically active and immunologically detectable collagenase was reduced by 70-82% in the cultures derived from the lesion as compared to controls (p less than 0.005). Fibroblasts derived from the lesions also displayed a mean population doubling time of 1.17 +/- 0.08 days compared to 1.83 +/- 0.24 and 1.92 +/- 0.09 days for control cell strains and cells derived from normal skin of the patient, respectively (p less than 0.025). These results suggest that the excessive deposition of collagen in this case may have resulted from decreased local degradation of collagen. Enhanced proliferative capacity of the regional fibroblasts may have contributed to the accumulation of collagen in these lesions.

Peripheral nerve entrapment syndromes in chronic hemodialysis patients

15 of 271 patients (6%) treated with chronic hemodialysis developed peripheral nerve entrapment syndrome of the median or the ulnar nerve. The majority of these patients were female (p less than 0.03). Fistulas located in arms with nerve entrapment tended to have higher flow rates than fistulas located in arms without nerve entrapment (57%) vs. 4.4%, p less than 0.001). There was no correlation with the renal diagnosis, previous access surgery in the involved arm, the type of vascular access used, the duration of hemodialysis, the adequacy of dialysis, calcium or phosphate homeostasis, plasma parathyroid levels, or thyroid function. Surgical intervention successfully relieved all symptoms. Return of normal renal function dose not reverse this disorder. Peripheral nerve entrapment is a common surgically correctable cause of neuropathy of the upper extremities in hemodialysis patients.

The association of submucous cleft palate and clefting of the primary palate

478 records of patients with cleft palate were reviewed to determine the prevalence and significance of submucous cleft palate associated with clefting of the primary palate. The prevalence of submucous cleft palate in the 71 patients with clefts of the primary palate (SMCP-CL) was 13 per cent. This is two to three times greater than the prevalence of isolated submucous cleft palate found in cleft palate clinic patients. Patients with SMCP-CL often had the symptoms of velopharyngeal incompetence (VPI) and middle ear disease. The increased prevalence of SMCP and frequent symptomatology of patients with clefting of the primary palate make it essential that patients with cleft lip have early, thorough evaluation for SMCP. Early detection of SMCP associated with cleft lip and close follow-up permits the prevention of ear problems and the proper management of VPI should it develop.

A randomized comparison of four incisions for orbital fractures

We previously compared conjunctival and subciliary incisions for exposure of orbital floor and infraorbital rim fractures. A prospective randomized comparison of lower eyelid and orbital rim incisions was then undertaken and results compared with our previous study. Lower eyelid and orbital rim incisions provided more rapid access to fracture sites. Fracture exposure was adequate with all but conjunctival incisions; lateral canthotomy was added in 56 percent of cases to improve exposure. There were minimal or no intraoperative and postoperative complications except for a 42 percent incidence of ectropion following subciliary incisions. Scar appearance was similar in the four groups, except when an isolated conjunctival incision was used, which produced an invisible scar.

Trigger finger and thumb, secondary to amyloidosis

We present a case in which infiltration of the flexor tendons and the fibrous sheaths of the digital flexors with amyloid caused triggering at both the entrance to the fibrous sheaths and at the decussation of the sublimis tendons.

Congenital lip pits and Hirschsprung's disease

A newborn infant with aganglionosis of the entire colon and terminal ileum also had congenital lip pits and a submucous cleft palate. These anomalies may be added to the growing list of conditions associated with Hirschsprung's disease.

A comparison of three technics of palatorrhaphy: in-hospital morbidity

We report the first randomized prospective comparison of different techniques of palatorrhaphy. The in-hospital morbidity of the Wardill-Kilner repair (Group I), von Langenbeck repair (Group II), and von Langenbeck repair with superiorly based pharyngeal flap (Group III) was evaluated in 47 patients. There were no deaths. Transfusion was needed only in Group I patients (p less than 0.01). Postoperative airway obstruction was significantly more common in Group III patients than in Group I (0 per cent or II (6 per cent) (p less than 0.05). Thus the in-hospital morbidity was least following the von Langenbeck repair.

Carpal tunnel syndrome following vascular shunts for hemodialysis

Carpal tunnel syndrome developed in the hands of two patients five to six months after Quinton-Scribner vascular shunts for hemodialysis were removed from the forearm of the symptomatic upper extremity. Thickened flexor tendon synovium within the carpal tunnel in al three cases suggests that the cause is an increase in the volume of the contents within the rigid confines of the carpal canal. Division of the transverse carpal ligament and synovectomy resulted in complete relief of symptoms 4, 14, and 23 months after operation. Carpal tunnel syndrome should be considered an additional new complication of vascular shunt procedures in patients treated by hemodialysis for renal failure.