Swimming mechanics and behavior of the shallow-water brief squidLolliguncula brevis

Although squid are among the most versatile swimmers and rely on a unique locomotor system, little is known about the swimming mechanics and behavior of most squid, especially those that swim at low speeds in inshore waters. Shallow-water brief squid Lolliguncula brevis, ranging in size from 1.8 to 8.9 cm in dorsal mantle length (DML), were placed in flumes and videotaped, and the data were analyzed using motion-analysis equipment. Flow visualization and force measurement experiments were also performed in water tunnels. Mean critical swimming speeds (Ucrit) ranged from 15.3 to 22.8 cm s–1, and mean transition speeds (Ut; the speed above which squid swim exclusively in a tail-first orientation) varied from 9.0 to 15.3 cm s–1. At low speeds, negatively buoyant brief squid generated lift and/or improved stability by positioning the mantle and arms at high angles of attack, directing high-speed jets downwards (angles >50°) and using fin activity. To reduce drag at high speeds, the squid decreased angles of attack and swam tail-first. Fin motion, which could not be characterized exclusively as drag- or lift-based propulsion, was used over 50–95 % of the sustained speed range and provided as much as 83.8 % of the vertical and 55.1 % of the horizontal thrust. Small squid (<3.0 cm DML) used different swimming strategies from those of larger squid, possibly to maximize thrust benefits from vortex ring formation. Furthermore, brief squid employed various unsteady behaviors, such as manipulating funnel diameter during jetting, altering arm position and swimming in different orientations, to boost swimming performance. These results demonstrate that locomotion in slow-swimming squid is complex, involving intricate spatial and temporal interactions between the mantle, fins, arms and funnel.

Prospective trial of thick vs standard split-thickness skin grafts in burns of the hand

For best function and appearance, thick skin grafts for hands are generally preferred to thinner grafts. But how thick is thick enough? This prospective randomized trial was designed to compare 0.015-inch skin grafts for burned hands to hand grafts that are 0.025 inches thick. Consecutive patients receiving skin grafts to hands were randomized to have sheet grafts using donor sites of 0.015-inch or 0.025-inch thickness. To prevent delayed healing and potential hypertrophic scarring, the thick graft donor sites were grafted with 0.008-inch grafts. There were no significant differences in range of motion, final appearance, or patient satisfaction between the two groups at 1 year. There were problems with donor site healing in both groups. We recommend that hand grafts for adults be at least 0.015 inches thick but do not see an advantage to the use of very thick (0.025-inch) grafts, even with thin split-thickness skin grafts to the donor site.

Treatment of sexual offenders who are in categorical denial: a pilot project

This paper describes an approach to treatment for sexual offenders who are in categorical denial. Other efforts to have them, at least partially, admit responsibility had failed and they were to be released from prison without any treatment. Evidence that suggests denial is not predictive of risk and that treatment may reduce the risk of these offenders is reviewed. Essentially, this paper offers a possible approach to dealing with these intractable deniers which, it is suggested, is better than not trying to modify their risk, and that may prove to be effective.

[Anesthesia in patients with myasthenia gravis]

Myasthenia gravis is a chronic autoimmune disease characterised by progressive weakness and easy fatigability of voluntary skeletal muscles. These symptoms are related to a decrease in the number of functional acetylcholine receptors, impaired neuromuscular transmission, and a broadened neuromuscular cleft. Symptomatic treatment is based on anticholinesterases in order to increase the synaptic dwell of acetylcholine. Immune therapy includes immune suppressive drugs, plasma exchange, immunoglobulins, and thymectomy. Anticholinesterase therapy should be continued in the current mode until anaesthesia. Regional anaesthesia should be preferred. Although sensitivity to non-depolarising neuromuscular blocking agents is increased, muscle relaxants can be administered during general anaesthesia as long as neuromuscular monitoring assesses their individual effect. Due to the individual variability in the response to muscle relaxants, accurate titration in combination with pre- and intraoperative neuromuscular monitoring is essential for myasthenic patients. Postoperatively, intensive care observation is mandatory including neuromuscular monitoring.

Tumorigenic potential of extracellular matrix metalloproteinase inducer

Extracellular matrix metalloproteinase inducer (EMMPRIN), a glycoprotein present on the cancer cell plasma membrane, enhances fibroblast synthesis of matrix metalloproteinases (MMPs). The demonstration that peritumoral fibroblasts synthesize most of the MMPs in human tumors rather than the cancer cells themselves has ignited interest in the role of EMMPRIN in tumor dissemination. In this report we have demonstrated a role for EMMPRIN in cancer progression. Human MDA-MB-436 breast cancer cells, which are tumorigenic but slow growing in vivo, were transfected with EMMPRIN cDNA and injected orthotopically into mammary tissue of female NCr nu/nu mice. Green fluorescent protein was used to visualize metastases. In three experiments, breast cancer cell clones transfected with EMMPRIN cDNA were considerably more tumorigenic and invasive than plasmid-transfected cancer cells. Increased gelatinase A and gelatinase B expression (demonstrated by in situ hybridization and gelatin substrate zymography) was demonstrated in EMMPRIN-enhanced tumors. In contrast to de novo breast cancers in humans, human tumors transplanted into mice elicited minimal stromal or inflammatory cell reactions. Based on these experimental studies and our previous demonstration that EMMPRIN is prominently displayed in human cancer tissue, we propose that EMMPRIN plays an important role in cancer progression by increasing synthesis of MMPs.

Epstein-Barr virus and survival after Hodgkin disease in a population-based series of women

BACKGROUND

Epstein-Barr virus (EBV) positive Hodgkin disease (HD), as defined by the presence of EBV genes or gene products in the malignant cells, differs epidemiologically from EBV negative HD. However, survival patterns for EBV-defined HD have not been well studied. To determine if EBV status influenced survival time after HD, the authors investigated a large, population-based series of female patients.

METHODS

For 311 female patients living in the Greater San Francisco Bay Area who were aged 19-79 years with HD diagnosed between mid-1988 and 1994, histopathologically rereviewed archived biopsy specimens were assayed for EBV with immunohistochemistry and in situ hybridization. The 53 subjects with EBV positive and the 258 with EBV negative HD were observed for vital status through 1998; overall survival was analyzed with Kaplan-Meier and Cox proportional hazards regression methods.

RESULTS

Epstein-Barr virus positive HD patients were older, received diagnosis at a later stage, and were less likely to have nodular sclerosis histology than EBV negative patients. Deaths were reported for 21 (40%) EBV positive and 37 (14%) EBV negative patients. No survival differences were observed between EBV positive and negative women aged 19-44 years, but survival was significantly poorer in women aged 45-79 years with EBV positive HD. Regression analysis confirmed this strong negative effect of EBV positive status on survival (hazard ratio for death, 3.0; 95% confidence interval, 1.5-6.2) as unrelated to age, stage at diagnosis, or tumor histology.

CONCLUSIONS

This study found a marked survival disadvantage for EBV positive HD in older but not young adult women. These findings suggest influences of both EBV status and age on HD survival, as well as pathogenesis.

Preanesthetic train-of-four fade predicts the atracurium requirement of myasthenia gravis patients

BACKGROUND

The most sensitive diagnostic criterion of myasthenia gravis is a decrement in the muscular response to repetitive stimulation. The authors hypothesized that myasthenia gravis patients who show a train-of-four ratio (T4/T1) < 0.9 in the preanesthetic period will have increased sensitivity to nondepolarizing neuromuscular blocking agents compared with myasthenia gravis patients with preanesthetic T4/T1 > or = 0.9.

METHODS

After institutional review board approval was obtained, 20 electrophysiologically documented myasthenia gravis patients were studied. Current pyridostigmine therapy was continued until the morning of surgery. Before induction of anesthesia, neuromuscular transmission was recorded from the hypothenar muscles using electromyography with train-of-four stimulation of the ulnar nerve. According to the T4/T1 ratio, patients were assigned to the "normal" group (T4/T1 > or = 0.9) or the "decrement" group (T4/T1 < 0.9). After induction of intravenous anesthesia, the effective dose to achieve a 95% neuromuscular blockade (ED95) for atracurium was assessed with a cumulative bolus technique. Postoperatively, pyridostigmine was titrated to obtain a T4/T1 > 0.75 and to treat residual myasthenic symptoms.

RESULTS

In 14 patients, preanesthetic T4/T1 was > or = 0.9 (normal), whereas 6 patients presented with T4/T1 < 0.9 (decrement). Decrement patients had a lower ED95 of 0.07 +/- 0.03 mg/kg atracurium (mean +/- SD) compared with normal patients with an ED95 of 0.24 +/- 0.11 mg/kg atracurium (P = 0.002). All patients were extubated within 30 min after surgery. Postoperative pyridostigmine infusion did not differ significantly between groups.

CONCLUSIONS

The requirement for atracurium is significantly reduced in myasthenia gravis patients with a T4/T1 ratio < 0.9 before anesthesia. This study indicates that routine neuromuscular monitoring in myasthenia gravis patients should be extended into the preinduction period to identify patients who require less atracurium.

Electron correlations observed through intensity interferometry

Intensity interferometry was applied to study electron correlations in doubly ionizing ion-atom collisions. In this method, the probability to find two electrons emitted in the same double ionization event with a certain momentum difference is compared to the corresponding probability for two uncorrelated electrons from two independent events. The ratio of both probabilities, the so-called correlation function, is found to sensitively reveal electron correlation effects, but it is rather insensitive to the collision dynamics.

Effect of carbohydrate ingestion on glycogen resynthesis in human liver and skeletal muscle, measured by (13)C MRS

This study investigated the effect of carbohydrate (CHO) ingestion on postexercise glycogen resynthesis, measured simultaneously in liver and muscle (n = 6) by (13)C magnetic resonance spectroscopy, and subsequent exercise capacity (n = 10). Subjects cycled at 70% maximal oxygen uptake for 83 +/- 8 min on six separate occasions. At the end of exercise, subjects ingested 1 g/kg body mass (BM) glucose, sucrose, or placebo (control). Resynthesis of glycogen over a 4-h period after treatment ingestion was measured on the first three occasions, and subsequent exercise capacity was measured on occasions four through six. No glycogen was resynthesized during the control trial. Liver glycogen resynthesis was evident after glucose (13 +/- 8 g) and sucrose (25 +/- 5 g) ingestion, both of which were different from control (P < 0.01). No significant differences in muscle glycogen resynthesis were found among trials. A relationship between the CHO load (g) and change in liver glycogen content (g) was evident after 30, 90, 150, and 210 min of recovery (r = 0.59-0. 79, P < 0.05). Furthermore, a modest relationship existed between change in liver glycogen content (g) and subsequent exercise capacity (r = 0.53, P < 0.05). However, no significant difference in mean exercise time was found (control: 35 +/- 5, glucose: 40 +/- 5, and sucrose: 46 +/- 6 min). Therefore, 1 g/kg BM glucose or sucrose is sufficient to initiate postexercise liver glycogen resynthesis, which contributes to subsequent exercise capacity, but not muscle glycogen resynthesis.

Risk of myocardial infarction in young female smokers

OBJECTIVES

To determine the extent of risk of myocardial infarction from cigarette smoking in young women, and to examine the relation of smoking with other putative risk factors.

DESIGN

Community based case control study.

SETTING

England, Scotland, and Wales.

PATIENTS

Women (n = 448) between 16 and 44 years old with a diagnosis of incident myocardial infarction between 1 October 1993 and 16 October 1995. Controls (n = 1728) were age and general practice matched women without a diagnosis of myocardial infarction.

OUTCOMES MEASURES

Odds ratios for risk of myocardial infarction associated with smoking and other risk factors.

RESULTS

Odds ratios for myocardial infarction in smokers versus non-smokers showed a strong dose response, from 2.47 (95% confidence interval (CI) 1.12 to 5.45) in smokers of 1-5 cigarettes per day to 74.6 (95% CI 33.0 to 169) in smokers of >/= 40 cigarettes per day. There was no interaction of smoking with use of oral contraceptives, but there were additive risks with other clinical risk factors such as hypertension and diabetes. It is estimated that if all women aged 16-44 years were able to stop smoking, 400 cases of myocardial infarction per annum (of whom 112 would die) would be prevented.

CONCLUSIONS

In young women the risk of myocardial infarction from smoking was considerable, and heavy smokers with other risk factors were especially at risk.

[Neuromuscular recovery following mivacurium is predictable in patients with severe systemic disease prognoses]

OBJECTIVES

Fast recovery from mivacurium-induced neuromuscular blockade is impaired in patients with decreased plasma cholinesterase activity which is often associated with dysfunction of different organs. Nevertheless, predictability of neuromuscular recovery may be given. Thus, this study evaluates parameters to predict individual neuromuscular recovery in patients with uncommon diseases.

METHODS

84 male or female patients (18-70 years of age) were allocated to one of two groups according to their ASA risk profile (without severe systemic diseases: ASA 1 and 2; with severe systemic diseases: ASA 3 and 4). Plasma cholinesterase activity (PChE) had been determined preoperatively. Anaesthesia was performed with propofol and fentanyl. Neuromuscular transmission was monitored by electromyography. The ulnar nerve was stimulated by train-of four stimuli and neuromuscular transmission was measured at the hypothenar. After mivacurium 0.1 mu mg/kg, an infusion of mivacurium was adjusted to maintain T1/T0 at approximately 5% for at least 60 min. Duration from application of the initial bolus until recovery to T1/T0 = 5% (dur 5), the mean mivacurium infusion rate (IR), infusion time, the early recovery time from cessation of infusion to T1/T0 = 25% (rec 25) and the final recovery time from T1/T0 = 25% to T4/T1 = 75% (final rec) was measured. Statistical analysis of data was performed using t-tests. (alpha = 0.05). Predictability of the recovery times (rec 25 and final rec) was tested by multiple linear least-squares regressions. Dependent variables were PChE, dur 5, IR, infusion time, and rec 25, respectively. To test for predictability of neuromuscular blockade by mivacurium with respect to severe systemic diseases, the ASA risk score was defined to be the second independent variable at each regression, the respective interaction was defined to be the third independent variable (variable 1 x group). Variables entered multiple regression analysis in a forward stepwise manner (F > 4.0).

RESULTS

PChE was significantly lower in patients with severe systemic diseases (3.7 +/- 1.2 kU/l vs. 4.5 +/- 0.9 kU/l), dur 5 significantly prolonged (17.3 +/- 7.3 min vs. 11.0 +/- 3.0 min), IR significantly lower (4.6 +/- 2.6 micrograms/kg/min vs. 6.5 +/- 2.8 micrograms/kg/min), and rec 25 (8.7 +/- 4.0 min vs. 6.0 +/- 1.7 min) as well as final rec (23.0 +/- 16.3 min vs. 13.0 +/- 3.7 min) significantly prolonged compared to patients without severe systemic diseases. Both recovery intervals correlated significantly with PChE, dur 5, or IR, but not with the ASA risk score. Multiple regression analysis revealed a close correlation between rec 25 and final rec very closely (R2 = 0.875). Prolonged mivacurium infusion time and additionally high ASA risk score were correlated with a prolonged neuromuscular recovery (R2 = 0.130).

DISCUSSION

Prolonged neuromuscular recovery could be predicted from a reduced PChE, a prolonged duration of action of the initial mivacurium bolus and a decreased mivacurium-infusion rate required to maintain a 95% neuromuscular blockade. Measurement of plasma cholinesterase and monitoring of mivacurium induced neuromuscular blockade can avoid resting neuromuscular blockade postoperatively despite of prolonged neuromuscular recovery.

Full-thickness grafting of acute eyelid burns should not be considered taboo

Split-thickness skin grafts are commonly used for the treatment of acute eyelid burns; in fact, this is dogma for the upper lid. Ectropion, corneal exposure, and repeated grafting are common sequelae, almost the rule. It was hypothesized that for acute eyelid burns, the use of full-thickness skin grafts, which contract less than split-thickness skin grafts, would result in a lower incidence of ectropion with less corneal exposure and fewer recurrences. The records of all patients (n = 18) who underwent primary skin grafting of acutely burned eyelids (n = 50) between 1985 and 1995 were analyzed retrospectively. There were 10 patients who received full-thickness skin grafts (12 upper lids, 8 lower lids) and 8 patients who received split-thickness skin grafts (15 upper lids, 15 lower lids). Three of 10 patients (30 percent) who received full-thickness skin grafts and 7 of 8 patients (88 percent) who received split-thickness skin grafts developed ectropion and required reconstruction of the lids (p = 0.02). No articles were found substantiating the concept that only split-thickness grafts be used for acute eyelid burns. The treatment of acute eyelid burns with full-thickness rather than split-thickness skin grafts results in less ectropion and fewer reconstructive procedures. It should no longer be considered taboo and should be carried out whenever possible and appropriate.

Remission of psoriasis after treatment with interferon-alfa and 2-chlordeoxyadenosine for hairy cell leukemia

2-Chlordeoxyadenosine (2-CdA) is an antineoplastic/immunosuppressive agent used to treat hairy cell leukemia (HCL), chronic lymphocytic leukemia, and low-grade lymphomas. Its immunomodulatory properties, however, may allow its future use in the treatment of psoriasis. We report a patient with psoriasis and HCL who was treated for 1 week with continuous intravenous infusion of 2-CdA for recurring HCL. Both the psoriasis and the HCL cleared. Four years after 2-CdA treatment, the patient has psoriasis on only 1% of his body surface area. 2-CdA induces lymphocytopenia, which may explain the improvement in this patient's psoriasis.