Assembly of high-areal-density deuterium-tritium fuel from indirectly driven cryogenic implosions

The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement. These conditions were obtained using 192 laser beams with total energy of 1-1.6 MJ and peak power up to 420 TW to create a hohlraum drive with a shaped power profile, peaking at a soft x-ray radiation temperature of 275-300 eV. This pulse delivered a series of shocks that compressed a capsule containing cryogenic deuterium-tritium to a radius of 25-35 μm. Neutron images of the implosion were used to estimate a fuel density of 500-800 g cm(-3).

Demonstration of ignition radiation temperatures in indirect-drive inertial confinement fusion hohlraums

We demonstrate the hohlraum radiation temperature and symmetry required for ignition-scale inertial confinement fusion capsule implosions. Cryogenic gas-filled hohlraums with 2.2 mm-diameter capsules are heated with unprecedented laser energies of 1.2 MJ delivered by 192 ultraviolet laser beams on the National Ignition Facility. Laser backscatter measurements show that these hohlraums absorb 87% to 91% of the incident laser power resulting in peak radiation temperatures of T(RAD)=300 eV and a symmetric implosion to a 100 μm diameter hot core.

Characterization of the spermiation response, luteinizing hormone release and sperm quality in the American toad (Bufo americanus) and the endangered Wyoming toad (Bufo baxteri)

Spermiation and LH release in response to several methods of LHRH administration were assessed in the American toad (Bufo americanus), and the most successful method was tested in the endangered Wyoming toad (Bufo baxteri). Specific objectives were to: (1) compare spermiation responses and plasma LH concentration after invasive and non-invasive LHRH treatments; (2) evaluate sperm production in response to different LHRH dosages; (3) characterize the timing of sperm release post LHRH treatment; and (4) assess sperm quality (motility, viability, morphology and acrosomal status). Male American toads were administered 4 microg LHRH by one of four routes: (1) intraperitoneal injection (i.p.); (2) subcutaneous injection (s.q.); (3) dorsal dermis absorption (d.d.a.); and (4) ventral dermis absorption (v.d.a.). Aspermic urine only was collected from saline-treated controls and d.d.a. animals. Several v.d.a. animals released spermic urine; however, all LHRH-injected toads released spermatozoa. I.p. animals produced higher sperm and LH concentrations than s.q. animals. The spermiation response in animals treated i.p. with 1 microg LHRH was similar to that in animals treated with 4 microg, but lower LHRH dosages tested produced inferior responses. Sperm production in responsive animals increased over time during the 12-h sampling interval. Regardless of treatment, most American toad spermatozoa were motile, viable, and acrosome-intact. Endangered Wyoming toads were treated i.p. with 4 microg LHRH, and spermic urine was collected. Although most spermatozoa were viable and acrosome-intact, a considerable percentage possessed structurally abnormal heads. A single i.p. injection of LHRH appears to be a reliable and safe method for controlling spermiation in toads and may be useful for assisting endangered amphibian propagation.

Shoulder numbness in a patient with suprascapular nerve entrapment syndrome: cutaneous branch of the suprascapular nerve: case report

OBJECTIVE AND IMPORTANCE

The ability to diagnose peripheral nerve disorders is dependent on knowledge of the anatomic course and function of the nerves in question. The classic teaching regarding the suprascapular nerve (SScN) is that it has no cutaneous branches, despite the fact that a cutaneous branch was first reported in the anatomic literature 20 years ago.

CLINICAL PRESENTATION

We describe a case of a 35-year-old male patient who presented with right shoulder pain and atrophy and weakness of the right supra- and infraspinatus muscles. During the examination, he was also noted to have an area of numbness involving the right upper lateral shoulder region. Electrical study results were consistent with SScN entrapment at the suprascapular notch.

INTERVENTION

The patient underwent surgical decompression 7 months after the onset of his symptoms. The patient noted resolution of his shoulder pain immediately after the procedure, and his shoulder sensory disturbance had improved by 2 weeks. At 9 months after surgery, he remained pain-free, his shoulder sensation was normal, and his motor abnormalities had improved significantly.

CONCLUSION

This case provides clinical evidence for the presence of a cutaneous branch of the SScN, as described in cadaveric studies. Although shoulder numbness demands a search for alternative diagnoses, it does not necessarily exclude the diagnosis of SScN entrapment.

Effects of pollen load size and composition on pollen donor performance in wild radish, Raphanus sativus (Brassicaceae)

A critical concern in the debate over the importance of sexual selection in plants is whether the nonrandom mating demonstrable in greenhouse crosses can occur in the field. Field populations likely experience smaller and more variable pollen load sizes than those that have been used in many greenhouse experiments. Therefore, we performed a greenhouse experiment in which we varied both pollen load size and composition in wild radish, Raphanus sativus, and examined the paternity of seeds. We used five maternal plants and four pairs of pollen donors. We were able to produce pollen loads of 40, 118, and 258 grains per stigma. The smallest of the pollen loads was scant enough to result in a slight, but significant reduction in seed number per fruit. While variation in pollen load composition significantly affected the proportions of seeds fathered by different donors, variation in pollen load size did not. The relative performance of different donors was constant across pollen load sizes, suggesting that, for this species, differential performance of pollen donors can occur at pollen load sizes that are likely to occur in field populations.

Four-level cervical corpectomy

STUDY DESIGN

Retrospective analysis of 31 cases of cervical spondylotic myelopathy treated by four-level subaxial cervical corpectomy.

OBJECTIVE

To determine whether extremes of anterior decompression and fusion have inordinate or unique levels of morbidity.

SUMMARY OF BACKGROUND DATA

There is a paucity of data on experience with four-level corpectomy. However, counsel against such surgery can be found.

MATERIALS AND METHODS

The records and studies of 31 consecutive cases of cervical spondylotic myelopathy, treated by four-level corpectomy, were retrospectively analyzed. Patients in 26 cases were observed longer than 2 years. No hardware was used in the procedures. External orthosis, worn for 6 months, was a Philadelphia-type collar in 25 patients and a halo vest in 6.

RESULTS

Three patients died within 3 weeks of surgery (9.7%). Delayed radiculopathy occurred in four patients after surgery, three had acute graft complications, and one had pseudomeningocele, for a morbidity rate of 25.8%. There was no infection or worsened myelopathy.

CONCLUSIONS

No unique morbidity is associated with extremes of subaxial decompression when compared with surgery of lesser extent.

Estimates of weight that subjects can lift frequently in functional capacity evaluations

BACKGROUND AND PURPOSE

This study was designed to determine whether the maximum weight that can be lifted during 33% to 67% of a workday (weight lifted frequently) can be accurately predicted from other data gathered during a functional capacity evaluation (FCE). The best equations for estimating weight lifted frequently were also identified, and the interrater reliability for measurements obtained during a 6-day FCE was calculated.

SUBJECTS

A retrospective chart audit was conducted of clients (36 female, 93 male) who completed 22-hour FCEs during a 6-day period. Ninety subjects had spinal problems, and 39 subjects had injuries not involving the spine. Subjects were randomly assigned to a model estimation group (n = 109) or a cross-validation group (n = 20).

METHOD

A stepwise multiple regression analysis identified the best predictors of weight lifted frequently, with subjects lifting from four different heights. The resulting equations were used to predict the weight for the cross-validation group, and predicted weights were compared with observed weights using t tests and correlation coefficients.

RESULTS

Regression equations explained between 27.3% and 93.0% of the variance in weight, with standard errors of estimation between 1.09 and 5.72. No differences between the mean observed and predicted scores were found when estimates were based on weight only occasionally lifted (maximum weight that could be lifted up to 33% of a workday).

CONCLUSION AND DISCUSSION

Estimates of weight lifted frequently based on weight lifted occasionally can be made, but the usefulness of these estimates is questionable. Clinicians should use caution when using estimations of weight lifted for return-to-work recommendations. [Saunders RL, Beissner KL, McManis BG. Estimates of weight that subjects can lift frequently in functional capacity evaluations.

Absence of tetrodotoxins in a captive-raised riparian frog, Atelopus varius

Bufonid frogs of the genus Atelopus contain two classes of skin toxins, namely the steroidal bufadienolides and the water-soluble tetrodotoxins. Frogs of the Panamanian species Atelopus varius have now been raised in captivity and levels in skin extracts of bufadienolides and of tetrodotoxin-like compounds assessed, using inhibition of [3H]ouabain binding and inhibition of [3H]saxitoxin binding, respectively. Levels of ouabain equivalents, corresponding to bufadienolides, were comparable to those found in wild-caught frogs from the same population in Panama, while tetrodotoxin-like activity was undetectable. The results strongly implicate environmental factors, perhaps symbiotic microorganisms, in the genesis of tetrodotoxins in the skin of frogs of the genus Atelopus, while indicating that the frog itself produces the skin bufadienolides.

Factors related to successful work hardening outcomes

BACKGROUND AND PURPOSE

The purpose of this study was to identify factors that predict successful work hardening outcomes. Two measures of success were used: return to work and case closure (ie, resolution of medical treatment issues).

SUBJECTS

Persons with spine-related injuries who completed a work hardening program were the subjects. One hundred fifteen subjects participated in a 3-month follow-up survey, and 111 subjects participated in a 12-month follow-up survey.

METHODS

Data were collected on subject characteristics, treatment history, job factors, program payer, and program factors. Subjects were contacted by telephone at 3 and 12 months after program completion to determine work status. Logit analysis was used to identify predictors of successful versus unsuccessful outcomes.

RESULTS

Three months after program completion, 68% of the subjects had returned to work and 86% had successful case closure. Twelve months after program completion, 77% of the subjects had returned to work and 90% had successful case closure. The more treatment subjects received prior to entering the program, the less likely they were to be working or achieving case closure following treatment. Subjects' work status and initial time off of work were factors predicting early return to work, but not 12 months after program completion. Subjects who were working with an attorney were less likely to achieve case closure than those who were not working with an attorney. Subjects who were satisfied with the program were more likely to have achieved case closure or return to work than those who were not satisfied with the program.

CONCLUSION AND DISCUSSION

Several factors have been identified that predict successful work hardening outcomes. This information can be used to identify clients who are unlikely to benefit from work hardening.

Serum silicon levels are elevated in women with silicone gel implants

The metabolic fate of silicone gel leaked into the body from an implant is unknown. In this study, serum from 72 women with silicone gel breast implants and 55 control women was blindly assayed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elemental silicon. Samples were processed using materials free of silicon. The mean silicon level in controls was 0.13 +/- 0.07 mg/l (range 0.06-0.35 mg/l), while in implant patients, the mean was significantly higher at 0.28 +/- 0.22 mg/l (range 0.06-0.87 mg/l) (P < 0.01, Student's t-test with correction for unequal variances). Using the mean of the control group + 2 SD as a cutoff for normal range (0.27 mg/l), 25/72 (34.7%) implant patients exceeded this value, compared with 2/55 (3.6%) controls. There was no significant correlation between past rupture of one or both implants, current rupture at the time of the blood draw or the number of years with implants and silicon levels. The results suggest that elevations of serum silicon are seen in many women with silicone gel breast implants. The kinetics of this elevation and the actual chemical species of the measured silicon remain to be determined.

On the pathogenesis of the radiculopathy complicating multilevel corpectomy

Postoperative fifth cervical radiculopathy has been described after cervical corpectomy. One explanation for this complication is thought to be the factor of traction on cervical roots caused by a shifting of the spinal cord consequent to decompression. This theory is supported by our experience with 176 patients undergoing corpectomies for whom a lesser width of decompression all but eliminated the complication.

Elevated serum silicon levels in women with silicone gel breast implants

The metabolic fate of silicone gel leaked from an intact or ruptured prosthesis is unknown. In this study, serum was blindly assayed by inductively coupled plasma atomic emission spectroscopy (ICP-AES) for elemental silicon in 72 women with silicone gel breast implants and 55 control women (mean age 48 yr, both groups). Blood was drawn and processed using silicon-free materials. The mean silicon level in controls was 0.13 +/- 0.07 mg/L (range 0.06-0.35 mg/L), whereas in implant patients, the mean was significantly higher at 0.28 +/- 0.22 mg/L (range 0.06-0.87 mg/L) (P < 0.01, Student's t-test with correction for unequal variances). Using the mean of the control group + 2 SD as a cutoff for normal range (0.27 mg/L), 25/72 (34.7%) implant patients exceeded this value, compared with 2/55 (3.6%) controls. There was no significant correlation between past rupture of one or both implants, current rupture at the time of the blood draw, or the number of years with implants and silicon levels. The results suggest that serum silicon levels are elevated in many women with silicone gel breast implants. The chemical species involved and kinetics of this elevation remain to be determined.

Odor-associated idiopathic anaphylaxis. A case report

A 44 year old woman is described who appears to have idiopathic anaphylaxis triggered by chemical odors. Her case and a general discussion of anaphylaxis are presented. The known causes of anaphylaxis and a discourse on idiopathic anaphylaxis are given. The treatment of idiopathic anaphylaxis is discussed.

Geniculate ganglion: anatomic study with surgical implications

The geniculate ganglion and adjacent segments of the facial nerve were dissected in 11 human temporal bones to study the extent and distribution of ganglion cells. A histologic basis for the use of geniculate ganglionectomy as the treatment for geniculate neuralgia was sought. In 9 of 11 specimens (81.8%), the ganglion cell bodies appeared to be aggregated at the apex of the genu close to the origin of the greater superficial petrosal nerve. The mean ratio of the width of the ganglion cell cluster to the width of the facial nerve trunk at the level of the genu was 0.4. In two specimens, significant anatomic variation was present. One specimen showed extension of cell bodies into the labyrinthine segment of the facial nerve; another specimen showed a single ganglion cell in the region of the genu. These findings lead us to postulate that geniculate ganglionectomy may be ineffective as the sole treatment for certain cases of geniculate neuralgia, and that nervus intermedius section may also be required to achieve a more complete deafferentation.

Continuous infusion of intrathecal morphine to control acquired immunodeficiency syndrome-associated bladder pain

A 36-year-old man with acquired immunodeficiency syndrome had incapacitating dysuria and vesical pain secondary to interstitial cystitis. When medical management and suprapubic urinary diversion failed to control the symptoms the patient was started on subarachnoid morphine sulfate. Bupivacaine was added 1 year later via an implanted Therex M-3000 implantable continuous infusion pump, which has continued successfully for more than 18 months. We believe that subarachnoid narcotics and other analgesic agents, such as clonidine, bupivacaine hydrochloride and baclofen, may prove equally valuable in the treatment of bladder spasm and pain. Furthermore, implanted intrathecal ports and pumps may have less associated risk of infection than the percutaneous vascular access catheters presently used for the continuous delivery of medications in immunosuppressed patients.

Geniculate neuralgia: the surgical management of primary otalgia

Intractable, unexplained deep-ear pain presents a rare, albeit significant problem in otolaryngological and neurosurgical practice. The authors review their experience with 18 cases of primary otalgia during the past 15 years. A total of 31 surgical procedures were performed. Seventeen patients had sequential rhizotomies and one patient had microvascular decompression alone. Based on the clinical diagnosis, the nerves sectioned were singly or in combination: the nervus intermedius (14 patients), geniculate ganglion (10 patients), ninth nerve (14 patients), 10th nerve (11 patients), tympanic nerve (four patients), and chorda tympani nerve (one patient). Microvascular decompression of the involved nerves was undertaken in nine patients, in whom vascular loops were discovered. Adhesions (six patients), thickened arachnoid (three patients), and benign osteoma (one patient) were other intraoperative abnormalities noted. The overall success of these procedures in providing pain relief was 72.2%, and the mean follow-up period was 3.3 years (range 1 month to 14.5 years). There was no surgical mortality. Expected side effects were: decreased lacrimation, salivation, and taste related to nervus intermedius nerve section, and transient hoarseness and diminished gag related to ninth and 10th nerve section. Four patients developed sequelae consisting of sensorineural hearing loss, vertigo, and transient facial nerve paresis. One patient had a cerebrospinal fluid leak and another developed aseptic meningitis as postoperative complications. Except when primary glossopharyngeal neuralgia is the working diagnosis, a combined posterior cranial fossa-middle cranial fossa approach is recommended for adequate exploration and/or section of the fifth, ninth, and 10th cranial nerves as well as the geniculate ganglion and nervus intermedius.

Repair of a cerebrospinal fluid perilymph fistula primarily through the middle ear and secondarily by occluding the cochlear aqueduct

A 35-year-old man had a 5-year history of fluctuating hearing loss in his only hearing ear. History and diagnostic tests indicated a perilymph fistula, a diagnosis subsequently confirmed by exploration. Primary and secondary repairs temporarily ameliorated symptoms. A spinal fluid to middle ear fluid pathway was identified by radioactive tracer. A patent cochlear aqueduct indicated on computed tomography scan was found and repaired through a posterior cranial fossa approach. Hearing was preserved, remaining relatively stable during the 2-year follow-up period.

Neurosurgical complications after intranasal ethmoidectomy

Intranasal ethmoidectomy is a common otolaryngological procedure. Despite the potential for serious intracranial complications, there is a paucity of reports describing the neurosurgical complications of the procedure. Two patients with intracranial complications of intranasal ethmoidectomy, and the relevant medical literature, are reviewed. The anatomy of the ethmoid air cells and their relation to the intracranial cavity are described. The importance of definitive, emergent repair with attention to the potential for vascular injury is discussed.

Central corpectomy for cervical spondylotic myelopathy: a consecutive series with long-term follow-up evaluation

Since 1984, a consecutive series of patients with cervical spondylotic myelopathy has been treated by central corpectomy and strut grafting. This report focuses on 40 cases operated on between 1984 and 1987 and followed from 2 to 5 years. The perioperative complication rate was 47.5%, with a 7.5% incidence of persistent sequelae: severe C-5 radiculopathy in one patient, swallowing dysfunction in one, and hypoglossal nerve palsy in one. No single factor (age, duration of symptoms, or severity of myelopathy) was absolutely predictive of outcome; however, syndromes of short duration had the best likelihood of cure. Similar outcomes were associated, individually, with long duration of symptoms, age over 70 years, and severe myelopathy. After factoring a 5% regression of improvement, the long-term cure rate was 57.5% and the failure rate was 15%. Myelopathy worsening was not documented.

Influence of ration level and salinity on circulating thyroid hormones in juvenile Atlantic salmon (Salmo salar)

Following acute exposure to seawater (30 ppt), plasma thyroxine (T4) of Atlantic salmon (Salmo salar) smolts increased 80% in the first 6 hr, declined to initial levels after 24 hr, and remained stable for 18 days thereafter. In nonsmolts, plasma T4 did not rise immediately after exposure to seawater, fell slightly after 2 days, and remained low for 18 days. Plasma triiodothyronine (T3) of smolts and nonsmolts was not affected by acute exposure to seawater. To examine the effect of long-term adaptation to ration and salinity, Atlantic salmon smolts were acclimated to three salinities (0, 10, and 30 ppt) and four ration levels (0, 0.2, 0.8, and 1.6% wet weight per day) for 6 weeks. Plasma T4 increased with increasing ration level (P less than 0.001) but was not significantly affected by salinity (P = 0.4). Plasma T3 also increased with increasing ration (P less than 0.001) and was more strongly correlated with ration level (r = 0.85) and growth rate (r = 0.88) than was plasma T4 (r = 0.73 and 0.75, respectively). At low ration (0 and 0.2% per day), fish in 10 ppt had slightly but significantly lower plasma T3 than fish in 0 ppt. There was no effect of salinity on plasma T3 at the higher rations, nor did plasma T3 levels differ significantly in fish in 0 and 30 ppt at any ration. The results indicate that ration level is a more important influence on circulating levels of plasma thyroid hormones than is salinity.

Family × photoperiod interaction on growth in juvenile Atlantic salmon, Salmo salar

A factorial experiment was used to study genotype × environment interaction on growth of underyearling Atlantic salmon parr (Salmo salar). Thirty-six families, each represented by 200 randomly sampled hatchery-reared parr, the progeny of single-pair matings, were subjected to two photoperiod treatments. These were 16 h light: 8 h dark (16L: 8D) and a simulated natural photoperiod decreasing from 13L: 11D on September 8 to 9L: 15D on December 15, 1986. Families with small starting mean length or weight showed a greater difference between photoperiod treatments (16 h minus natural) for absolute gain in length and weight, resulting in family × photoperiod interaction without reranking of families between treatments. A family's length or weight distribution was generally bimodal. The expected (based on a general exponential model) and actual November and December upper mode proportions of families in the 16-h photoperiod were larger than those in the natural photoperiod treatment, for length and weight. Family × photoperiod interaction for upper mode size resulted from the reranking of families for the expected but not the actual values. In general, the 16-h photoperiod produced the biggest fish and the largest upper mode proportion. Photoperiods interacted with families. The lack of significant reranking of families in the two environments, when based on absolute gain or actual upper mode proportion, does not indicate an impediment to correlated genetic gains from selection in the alternate environment.Key words: Atlantic salmon, photoperiod, genotype × environment interaction, growth, bimodality.

Mitochondrial enzyme and Na(+), K (+)-ATPase activity, and ion regulation during parr-smolt transformation of Atlantic salmon (Salmon salar)

Atlantic salmon (Salmo salar) exposed to either simulated natural photoperiod (SNP) or continuous light (L24) were used to examine developmental changes in the presence and absence, respectively, of the parrsmolt transformation. Plasma osmolarity and ion concentrations were unaffected by photoperiod treatment. Gill Na(+), K(+)-ATPase specific activity increased 150% between February and June in SNP fish and was low and unchanged in L24 fish. Kidney Na(+), K(+)-ATPase specific activity varied within similar, narrow limits in both groups. Citrate synthase of liver, gill and kidney, expressed as specific activity or activity/g total body weight (relative activity), increased 25-60% between March and June in SNP fish. With the exception of kidney relative activity, citrate synthase activity declined to initial (March) levels by August. Liver, gill and kidney cytochrome c oxidase activity of the SNP group underwent similar though less marked changes. Liver, gill and kidney citrate synthase and cytochrome c oxidase activities of the L24 group remained relatively constant between March and August, and where significant differences occurred, they were lower than those of the SNP group. These results indicate that respiratory capacities of the liver, gill and kidney increase in smolls concurrent with preparatory osmoregulatory changes, and subsequently decline. The findings are consistent with a hypothesized transient increase in catabolic activity during the parr-smolt transformation that may be due to the metabolic demands of differentiation.

Endocrine-mediated photostimulation of growth in Atlantic salmon

The response of the Atlantic salmon (Salmo salar) pituitary to photoperiod manipulation was investigated histologically, and the observations were related to gross morphometric changes. Salmon were placed under either a simulated natural photoperiod (NP), a photoperiod complementary to the natural photoperiod (RP) or constant daylight (CL) in December. The latter two regimens stimulated the pituitary, particularly the somatotrops, and enhanced growth. After 6 weeks, the CL fish were longer than all others (P < 0.01) and their pituitaries showed marked hypertrophy, with many somatotrops and other cell types in mitosis. The RP fish were also longer (P < 0.01) than the NP animals at that time but their pituitaries appeared less stimulated than those of CL fish. However, the stimulation in CL and RP fish was not maintained beyond 3 months. At that time NP pituitaries more closely resembled the stimulated condition shown earlier by the RP glands. Our results confirm that changes in day length elicit corresponding changes in pituitary cytology and growth rates, albeit without eliminating an apparently innate growth cycle. While increased day length in winter may stimulate the pituitary, such regimens appear to render the gland refractory and cause a phase-shift in the rhythm. It is proposed that suitable interruptions in photostimulation may prolong stimulation.

Use of implantable pumps for central nervous system drug infusions to treat neurological disease

Increasing knowledge of the neurochemical aspects of central nervous system function raises the possibility of treating neurological disease by the appropriate manipulation of neurotransmitters, neuromodulators, and neurohormones. Clinical application of this knowledge has been inhibited, however, by long-standing problems with drug delivery to the central nervous system (CNS). The availability of implantable drug infusion pumps and stereotactic catheter placement techniques may overcome many of these problems. The problems of drug delivery to the brain and the present and potential uses of implantable drug pumps for neurological disease are discussed. In addition, the relationship between CNS drug infusion and neural tissue transplantation is briefly reviewed.

Magnetic resonance imaging in the diagnosis and treatment of Lhermitte-Duclos disease (dysplastic gangliocytoma of the cerebellum)

Lhermitte-Duclos disease is a rare disorder characterized by a slowly enlarging mass lesion in the cerebellum. The pathophysiology of the disease is poorly understood, but recent reports have suggested that a clinically significant mass may recur many years after total gross removal of the tumor. Computed tomography and angiography have been relatively insensitive in imaging the tumor either at presentation or during the postoperative period. The authors present three patients with histologically proven Lhermitte-Duclos disease who have undergone magnetic resonance imaging (MRI). In the first case, preoperative T1- and T2-weighted images clearly demonstrated the location and extent of the lesion, which was verified at operation. In the other two cases, only postoperative images were obtained. These demonstrated the extent of residual tumor and indicate a high probability of lesion expansion during periods of 4 and 10 years, respectively. We conclude that MRI is an important tool in both the diagnosis and the treatment of patients with Lhermitte-Duclos disease.

Coronary arteriosclerosis in Atlantic salmon. No regression of lesions after spawning

The incidence and severity of coronary arteriosclerosis were studied in 209 wild and cultured Atlantic salmon (Salmo salar L.) during various stages of recovery of bodily condition after spawning. All recently spawned fish had lesions of moderate to extreme severity. The incidence of lesions for each fish was high (73% to 94% of all arterial cross-sections examined). The incidence and severity of lesions did not decrease during 5 months in a group of wild salmon reconditioned in the laboratory. Wild salmon that were examined in the spring angling fishery in the Miramichi River, New Brunswick, about 5 months after spawning had a high incidence (89%) of severe lesions, not significantly different from recently spawned salmon from the same and another river. A population of cultured salmon sampled at intervals from a sea cage during 9 months after spawning showed no evidence of lesion regression, but rather a continued increase in both incidence and severity during recovery of bodily condition and growth. Thus, in contrast with previous studies with steelhead trout and Atlantic salmon where the possibility of lesion regression has been suggested, our observations on a large number of Atlantic salmon from various sources gave no evidence of lesion regression. Coronary arteriosclerosis in Salmo salar appears to be a progressive condition, which continues during recovery of bodily condition and growth after spawning.

External ventricular drainage for initial treatment of neonatal posthemorrhagic hydrocephalus: surgical and neurodevelopmental outcome

Thirty-seven infants were treated for posthemorrhagic hydrocephalus (PHH) with external ventricular drainage (EVD) in 1977-1985. The mean age at EVD placement was 13 days; the mean duration of drainage was 21 days, and an average of 1.8 drains was used per patient. Complications were apnea (10%), hemorrhage (8%) and ventriculitis (6%). Ten infants died from pulmonary disease unrelated to the surgery. Thirty-two percent of the survivors did not require a permanent shunt. Neurodevelopmental outcome was evaluated at a mean age of 38 months. Eighteen of the twenty-seven survivors (67%) had normal cognitive function, 3 had borderline and 6 (22%) had moderate to profound mental retardation. Nine of the children (33%) had a normal neuromuscular exam. One child had mild, 11 had moderate and 6 had severe cerebral palsy. Four children had serious visual impairment. The worst outcomes were in the children with parenchymal or large intraventricular hemorrhages.

Arteriosclerosis in Atlantic salmon. Effects of dietary cholesterol and maturation

Coronary arteriosclerosis was examined in cultured Atlantic salmon (Salmo salar L.) maintained on normal and cholesterol-enriched diets in both freshwater and saltwater during the period when they normally mature (June to December). The incidence of lesions was high (48% or greater) in all experimental subgroups (assigned according to diet, salinity, sex, and maturation status). The primary factor in the development of arteriosclerotic lesions was not established, but the high frequency of lesions in immature fish suggests that it was not maturation. However, maturation was associated with a significant increase in the incidence of lesions and was, therefore, an important secondary factor in the etiology of the disease. Furthermore, diet had a secondary influence on the development of lesions since the cholesterol supplement was also associated with an increase in the incidence of lesions. The cholesterol supplement significantly increased the total plasma cholesterol level in all subgroups; the low density lipoprotein fraction (total cholesterol minus the high density lipoprotein fraction) was also elevated in seven of eight paired subgroups. Plasma free fatty acids and triglycerides were unaffected by the cholesterol supplement. The elevated total cholesterol and low density lipoprotein levels resulting from the cholesterol-enriched diet and the associated increase in the incidence of lesions was most prominent in mature males and females held in freshwater. Salinity had no demonstrable effect on lesion incidence, but the severity of lesions tended to be greater in freshwater fish.

Continuous intrathecal hydromorphone and clonidine for intractable cancer pain

The use of hydromorphone and clonidine, delivered intrathecally by an implanted infusion pump, is described in a patient with intractable cancer pain. The patient was a 48-year-old woman with uterine cervical cancer-related pain that was poorly responsive to conventional oral narcotics. Hydromorphone was used because of the patient's history of morphine intolerance. When progressive intrathecal hydromorphone dosages were required, intrathecal clonidine (an alpha 2 adrenergic agonist) was infused concomitantly. Intrathecal hydromorphone and clonidine successfully controlled this patient's pain without the necessity to resort to destructive neurosurgery.

Table-fixed retractor system for noncranial surgery. Technical note

A retractor system based on the principle of table fixation of the retraction device has been fabricated and utilized in a broad range of noncranial procedures. Based on the refinement of self-retaining brain retractor methods, this device allows an atraumatic fixed exposure without the danger of "self-retained devices" impaling soft tissue and the compromises of hand-held retractors.

The effect of temperature on the vitellogenic response in Atlantic salmon post-smolts (Salmo salar)

Effects of low (3 degrees) and high (10 degrees) temperatures on the vitellogenic response to estradiol treatment were analyzed in female and male salmon post-smolts. Vitellogenic response as indicated by levels of circulating vitellogenin, hepatic protein, RNA, and nuclear count depends on the ambient temperature during hormone treatment but not on the previous 1 month acclimation temperature. Thus, the level of vitellogenin in the serum or hepatic RNA did not increase above the levels of the untreated controls in previously warm-acclimated smolts if the fish were exposed to low temperature water during treatment with estradiol. Conversely, cold-acclimated smolts showed increased levels of hepatic RNA and circulating vitellogenin only when transferred to 10 degrees water during treatment. No such response could be elicited if salmon were kept at 3 degrees during estradiol treatment. The negative influence of low ambient temperature on the vitellogenic response could not be eliminated by using higher doses of estradiol. Salmon post-smolts, long-term acclimated to 3 degrees revealed a significant vitellogenic response to estradiol only if the temperature during treatment was increased to 10 degrees. Estradiol treatment at 10 degrees stimulated the growth of liver as determined by the increase in liver somatic index and amounts of total hepatic protein, RNA, and nuclear count. On a per unit liver wet weight basis, however, only RNA increased above the level of the untreated control fish. As the nuclear count per gram of liver is similar in estradiol-treated and untreated groups, estradiol-induced liver growth in the salmon post-smolts may be accounted for by an increase in cell number (hyperplasia) rather than an increase in cell size (hypertrophy).

Spontaneous cerebrospinal fluid otorhinorrhea

Spontaneous cerebrospinal fluid (CSF) otorrhea implies the observation of CSF draining from the ear or nose without any previous history of traumatic or infectious etiology. The term does not exclude embryologic or developmental abnormalities. The condition may be life-threatening. Thus far it has been reported about twenty times. Because it is rare, misdiagnosis or failure to make a timely early diagnosis is common and proper therapy may be delayed. The purpose of this article is to review pertinent literature on this subject and to present two additional case reports. Emphasis will be placed on accuracy of diagnosis and on the surgical technique employed in repair of the discovered defect.

Tympanic membrane sensation

Sensation from the tympanic membrane is generally believed to be mediated via at least four cranial nerves, some authors describing discrete territories for each of these nerves. The lack of critical evidence for independent sensory areas prompted a clinical study of tympanic membrane sensation in 32 patients having known cranial nerve deficits. Tympanic membrane sensation was tested in four quadrants using a 300 mg bristle under a Zeiss operating microscope. The findings were highly suggestive of a predominantly nociceptive system. Any change relative to the opposite tympanum was usually anaesthesia. No complete trigeminal deficit retained perception in all tympanic quadrants. Facial, glossopharyngeal and vagal deficits alone never affected tympanic sensation. These findings support the trigeminal nerve as the principal sensory nerve to the tympanic membrane, supplemented only inconstantly and incompletely by the other cranial nerves.

A cranial nail for fetal shunting

A small number of human fetal hydrocephalics have been treated by ventriculoamniotic shunts of silastic tubing. The Colorado device appears to be the one most commonly used. The original experimental device tested on a primate model resembled a hollow shingle nail. This was designed by Michedja and Hodgen, contained a spring valve, measured approximately 32 X 4 mm and was placed by hysterotomy. An attractive feature of this design was its fixation by impaction in the skull, preventing displacement by fetal activity, a reported disadvantage with the silastic devices. To our knowledge, no one has used this nail-like design and tailored it to transuterine percutaneous placement in a human case.

Effects of temperature and season on the position holding performance of juvenile Atlantic salmon (Salmo salar)

The ability of wild and hatchery yearling Atlantic salmon (Salmo salar) to hold a position against water currents was tested in relation to water temperature and season. This species would not swim, but held positions on the bottom of the test apparatus. Their performance was, therefore, rated on the basis of critical holding velocity instead of critical swimming velocity, often used for other species. Qualitatively, the relationships of critical holding velocity with both temperature and season were similar for wild and hatchery fish. However, wild fish were consistently more able to hold positions against water currents so that the mean water velocities at which they were unable to stem water currents were 25–84% greater than those for hatchery fish. In the winter, the mean water velocities against which both wild and hatchery fish could no longer hold a position were 21.9–50.0% lower than in the summer. Seasonal changes in performance generally increased or decreased with water temperature except in winter when performance declined while water temperature was almost constant. Performance was high and almost unchanging for temperatures above 8 °C, but fell sharply below this temperature. We suggest that the sharp decrease in performance at 8 °C explains the previous observation that this species suddenly moves into the stream bed when temperature falls during the autumn.

Outcomes and complications of continuous intraspinal narcotic analgesia for cancer pain control

Preliminary reports of continuous intraspinal morphine analgesia have been enthusiastic regarding the resultant cancer pain control. Reports of continuous intraspinal infusion have not documented the duration of useful analgesia, need for concomitant analgesic therapies, or complication rates. Thus, the overall outcomes and complications of six chronic intrathecal and eight epidural morphine infusions were analyzed in the first 14 cancer pain patients implanted with continuous intraspinal morphine infusion reservoirs at this clinic. A five-point scale was used to assess the analgesic therapy required to maintain pain control during three consecutive intervals of intraspinal morphine infusion (zero to two months, two to six months, after six months). Comparison with pre-implant narcotic requirements revealed equal or reduced narcotic use for up to six months of therapy, with a definite trend toward escalation of intraspinal narcotics, systemic analgesia, and adjunctive procedures after two months. This occurred most likely due to narcotic tolerance and disease progression. Failure of pain control was the rule with continuous intraspinal morphine after six months. Three patients ultimately required neurolytic blocks. No clear difference was found in pain control requirements between epidural and intrathecal morphine infusion. No infection or respiratory depression occurred as a direct result of the intraspinal morphine implanted system.

Preliminary report: intracranial cholinergic drug infusion in patients with Alzheimer's disease

After toxicity studies in dogs, a preliminary feasibility trial of the continuous intracranial infusion of a muscarinic agonist was begun in four patients with biopsy-documented Alzheimer's disease. During the last 8 months, a totally implantable infusion system has been used to deliver bethanechol chloride into the cerebrospinal fluid of these patients at doses of 0.05 to 0.7 mg/day. Complications have been few and resolved spontaneously or were easily reversible. The subjective response to this treatment has been encouraging, with reports of improved cognitive and social function during drug infusion and a return to base line function with single-blind saline placebo infusions. Obviously, further evaluation will be necessary to demonstrate the efficacy of this treatment, and a double-blind placebo-controlled crossover trial is now being done. However, we think the preliminary results are encouraging and warrant the consideration of this approach as a potential treatment in patients with Alzheimer's disease.

The false fontanel

In the neonate, palpation of the anterior fontanel is recognized as a simple and reliable means for estimating intracranial pressure. With closure of the fontanel this aspect of the clinical examination is lost. The authors report a series of 15 shunted infants and children in whom a false fontanel was created by making a 2-cm craniectomy in the right parietal region and excising the underlying internal pericranium. This produces a cranial opening which, like the anterior fontanel, can be used for palpation and real-time ultrasound imaging of the brain. By removing the internal pericranium, reossification of the defect is delayed by more than 12 months. Sparing the dura propria avoids the risks of cerebrospinal fluid leak or brain herniation into the cranial window. This procedure is reported to be simple, reliable, and of value in assessing shunt function in hydrocephalic infants and young children. An illustrative case report is presented.

Use of cryoprecipitate coagulum to control tumor-bed bleeding. Case report

The case is presented of a 44-year-old woman who underwent reoperation under cardiac standstill for a recurrent left sphenoid wing meningeal hemangiopericytoma. Because of persistent accumulations of clot with clinical deterioration and shift on computerized tomography scanning, the patient was returned to the operating suite twice. At the second reoperation, hemostasis was finally achieved through the instillation of admixed cryoprecipitate, calcium, and activated thrombin.

Relief of continuous chronic pain by intraspinal narcotics infusion via an implanted reservoir

Ten patients with intractable pain (five cancer and five nonmalignant) were treated with continuous intraspinal morphine delivered by an implanted continuous infusion system. Both patient groups were evaluated and compared using an identical battery of psychometric examinations administered before and 12 weeks after therapy. The cancer-pain group reported significant reduction in pain on serial visual pain analogue scales at 12 weeks compared with no change in the nonmalignant-pain group reports despite a much lower baseline report in the cancer group. Both groups of patients reduced their oral narcotic requirement significantly during continuous intraspinal morphine infusion. While the cancer patients took more oral narcotic at baseline, at 12 weeks no difference existed in oral intake between the two groups. Both groups required significant serial increases in infused morphine, indicating that spinal opiate receptor tolerance occurs. The results of this study confirm the sustained analgesic efficacy reported earlier in cancer-related pain syndromes, thus supporting further cautious expansion of this therapy within the cancer-related pain population. In contrast, a poor response was seen in the nonmalignant-pain group, consistent with the unsatisfactory responses to many potentially analgetic approaches to chronic nonmalignant pain. We are thus discouraged from further use of this therapy in the patient with chronic nonmalignant pain.

Twist drill craniostomy and closed system drainage of chronic and subacute subdural hematomas

Based on reports in the literature on the success and low morbidity of twist drill craniostomy (TDC) and closed system drainage (CSD) for chronic subdural hematomas, a prospective study was initiated in 1981 and included all symptomatic patients presenting with a history and clinical and computed tomographic (CT) findings consistent with subacute or chronic subdural hematoma. A total of nine patients were treated with TDC and CSD as the initial procedure. An asymptomatic or progressively improving patient with greater than 50% reduction in subdural size by repeat CT scan was set as the end point of therapy. There were no complications, all patients improved with drainage, and seven were cured by this method alone. The results are compared retrospectively to surgically treated patients, and an overall decrease in morbidity and length of hospitalization are noted. The technique and CT scan correlations are described, and the rationale for use of this method is discussed in terms of our current understanding of the pathophysiology and complications of the disease.