Malyngamide H, an ichthyotoxic amide possessing a new carbon skeleton from the Caribbean cyanobacterium Lyngbya majuscula

Guided by ichthyotoxic activity against goldfish, a new lipopeptide, malyngamide H [1], and its corresponding free acid, 7-methoxytetradec-4(E)-enoic acid [2], have been isolated from the tropical marine cyanobacterium Lyngbya majuscula. The structure of the new carbon skeleton borne by malyngamide H was elucidated on the basis of spectroscopic analysis, mainly 2D nmr. The absolute stereochemistry of the cyclohexenone moiety of malyngamide H [1] was deduced by a combination of 2D NOESY and exciton chirality circular dichroism spectroscopy.

Radical and local excisional methods of sphincter-sparing surgery after high-dose radiation for cancer of the distal 3 cm of the rectum

BACKGROUND

Despite conventional attitudes that interdict sphincter-preservation surgery (SPS) for cancers arising in the terminal 3 cm of rectum, we have selectively employed high-dose preoperative external radiation (HDPER) and either radical or local excisional SPS techniques for rectal cancer arising between the 0.5 and 3 cm levels above the anorectal ring. We have reported a preliminary experience with HDPER and full-thickness local excision (FTLE) and three different methods of radical SPS. We now describe our experience with a single method of radical excision, transanal abdominal transanal proctosigmoidectomy with coloanal anastomosis (TATA) and FTLE in conjunction with HDPER for cancers of the distal 3 cm of rectum based on specific guidelines.

METHODS

Since 1984, 109 patients with cancers at or below the 3 cm level have been treated with HDPER in doses of 4,500-7,000 cGy and a sphincter-preserving radical or local excision method in a prospective rectal cancer management program. Sixty-five patients (group A) underwent transanal abdominal transanal radical proctosigmoidectomy with colonal anastomosis (TATA) and 44 patients (group B) underwent FTLE.

RESULTS

There was one death (1%). Mean follow-up was 40 months. Local recurrence rates for groups A and B were 9 and 14%, respectively. Kaplan-Meier 5-year actuarial survival was 85 and 90% for groups A and B, respectively, and 87% collectively.

CONCLUSION

Experience with 109 patients with cancers of the distal 3 cm of rectum indicates that SPS can be accomplished by either radical or local excisional methods with acceptable local control and survival if HDPER and strict selection guidelines are employed.

Prospective review of 278 endoscopic carpal tunnel releases using the modified chow technique

The results of 278 endoscopic carpal tunnel releases using the extrabursal dual portal Chow technique were analyzed prospectively. The majority of patients were pain free by the 57th postoperative day. The perioperative complication rate was 1.7%. The late complication rate was 2.8%. Two cases were converted to open carpal tunnel release. The average time to return to full-duty work was 65 days in those patients covered by worker's compensation, whereas it was 21 days in the privately insured (non-worker's compensation) patients. The endoscopic release of the transverse carpal ligament is an effective technique for the treatment of carpal tunnel syndrome with a low complications rate. Return to full employment requires more time in those patients covered by worker's compensation.

Structure and localization of the IGFBP-1 gene and its expression during liver regeneration

Insulin-like growth factor-binding protein-1s are important modulators of the insulin-like growth factors that may have both positive and negative effects on the ability of insulin-like growth factors to stimulate cell growth. The IGFBP-1 gene is one of the most highly induced immediate-early genes after partial hepatectomy. The IGFBP-1 gene is also expressed at a high level during fetal liver development and in response to nutritional changes and diabetes. Therefore it may have important roles in liver growth and metabolism. To begin to examine the regulation of this gene, we cloned and sequenced the entire mouse IGFBP-1 gene. Its structure is highly similar to that of the human gene, and, in addition to the exonic regions, the two genes are highly conserved in specific regions in the promoter and first intron. Analysis of this conservation allows us to predict important regulatory sites that define the tissue specific and insulin-mediated regulation of the gene and identify potential sites that might be important for the transcriptional induction during liver regeneration. The mouse gene is located on mouse chromosome 11; it is found at the boundary between regions in the mouse genome homologous to human chromosomes 22 and 7. We found IGFBP-1 mRNA in both parenchymal and nonparenchymal RNA after partial hepatectomy. Using in situ hybridization of IGFBP-1 mRNA in regenerating rat liver tissue, we demonstrated IGFBP-1 transcripts in several cell types. We found that IGFBP-1 gene induction after partial hepatectomy is paralleled by protein expression.(ABSTRACT TRUNCATED AT 250 WORDS)

Muscle bio-energetics in acute glycolytic block: in vivo phosphorus-nuclear magnetic resonance study of iodo-acetate injected rats

In vivo phosphorus nuclear magnetic resonance spectroscopy of muscle was performed at rest, during work and during postexercise recovery in rats injected with iodo-acetate (IA) (35-40 mg.kg-1, intra-arterially), in order to follow bio-energetic changes in muscle with acute glycolytic block. Three animals with contracture had very low ratios of phosphocreatine:inorganic phosphate (PCr:Pi) at rest (0.5-0.9). The PCr:Pi were normal at rest (6.9 +/- 2.0, +/- 2 SD) in all other rats. Exercise-induced continuous accumulation of phosphomonoesters (PME), the characteristic finding of glycolytic block, was observed. The end-exercise levels of PME correlated with the degree of block measured in vitro. During steady-state work, induced by nerve stimulation at four frequencies, PCr:Pi values were significantly lower (p less than 0.02) than the control values at 0.25, 1.0 and 2.0 Hz. The ATP levels fell during exercise to reach 75% +/- 7% of initial values. The recovery of PCr:Pi from exercise and the disappearance of PME were slow. Two animals which survived the IA injection demonstrated much lower PME accumulation 18 h later. It is concluded that in acute muscle glycolytic block: (1) energy metabolism is impaired during exercise and also at rest, (2) accumulating PME can serve as an indicator of the degree of glycolytic block, (3) ATP levels fall during work, and (4) postexercise recovery is slow. The findings are compared with 31P-NMR observations in chronic muscle glycolytic disorders.

Esmolol attenuates hemodynamic responses during fentanyl-pancuronium anesthesia for aortocoronary bypass surgery

We evaluated the effects of esmolol, a short acting (t1/2 beta = 9 min) beta-blocker on hemodynamics during noxious stimulation associated with aortocoronary bypass surgery. Group E (n = 10) and P (n = 10) patients had their morning dose of beta- or calcium blockers withheld except for nifedipine, and were given infusions of esmolol (E) or placebo (P) beginning prior to anesthetic induction and continuing until mediastinal dissection. Group S (n = 10) patients received their usual medication the morning of surgery and received neither esmolol nor placebo. All patients received fentanyl infusions for anesthesia and pancuronium for relaxation. Esmolol patients had no changes in heart rate throughout the study. In contrast, significant increases in heart rate occurred during induction, intubation, and surgical stimulation in Groups P and S. Esmolol patients had a statistically significant but transient increase in pulmonary capillary wedge pressure (PCWP) after intubation, which did not require treatment. There were no significant changes in PCWP in Group S and a decrease in PCWP in Group P patients. We conclude that esmolol was effective in attenuating potentially deleterious responses to noxious stimulation during fentanyl-pancuronium anesthesia.

Myocardial surgical revascularization after streptokinase treatment for acute myocardial infarction

Eighty-six patients admitted with evolving myocardial infarction within 6 hours of symptom onset were treated with streptokinase. Thirty-nine received intracoronary streptokinase, and 47 received intravenous streptokinase. There were no streptokinase-related complications. Twenty-three patients treated with intracoronary streptokinase and 28 patients receiving intravenous streptokinase underwent coronary artery bypass grafting. On admission, 16 patients receiving intracoronary streptokinase had electrocardiographic evidence of anterolateral evolving myocardial infarction and seven had evidence of inferior evolving myocardial infarction. Time from first symptom to intracoronary streptokinase was 4.4 +/- 1.6 hours. In seven patients, intracoronary streptokinase failed to open the obstructed coronary. All developed severe left ventricular hypokinesia in the area supplied by that coronary artery. In spite of recanalization, nine of 14 patients developed severe hypokinesia in the supplied area, and one an apical aneurysm. Four patients developed mild to moderate hypokinesia, and one had no left ventricular damage. On admission, 14 patients receiving intravenous streptokinase had electrocardiographic evidence of anterolateral evolving myocardial infarction and four had evidence of inferior evolving myocardial infarction. Time from first symptom to intravenous streptokinase was 3.2 +/- 1.5 hours. In seven patients, intravenous streptokinase failed to open the coronary, and all developed severe hypokinesia of the supplied area, with formation of apical left ventricular aneurysm in three. In 21 patients, intravenous streptokinase opened the artery. Eighteen angiographies performed 9.6 +/- 7.9 days after therapy showed a normal left ventricle in eight patients, moderate hypokinesia in seven, and severe hypokinesia in three. Time from first symptom to therapy was shorter in the patients receiving intravenous therapy (p less than 0.01). Coronary artery bypass grafting and four resections after left ventricular aneurysm were performed without operative death. Two patients receiving intracoronary therapy died in the hospital, and one died 2 months later from arrhythmias. Freedom from angina and rehabilitation (New York Heart Association Class I) were achieved in 69.5% of patients receiving intracoronary streptokinase and in 75% of patients receiving intravenous streptokinase. Thus streptokinase-induced thrombolysis salvages myocardium, and the intravenous route seems as effective as the intracoronary. Advantages of the former are earlier administration that might increase myocardial salvage, no invasive procedure, and lesser cost.

Non-cardiac surgery in patients with prior myocardial revascularization

Patients who had undergone aorto-coronary bypass grafts (ACBG) were assessed for the incidence of cardiac complications in the postoperative period following subsequent non-cardiac surgery. One hundred and twenty-one patients had 13 complications (11 per cent). A significantly higher risk of cardiac complications (27 per cent) was found in patients undergoing non-cardiac procedures in the first month after ACBG. This remained higher (17 per cent) until the sixth month following ACBG. Significant factors which increased the risk of cardiac complications in the postoperative period included preoperative congestive heart failure (33 per cent), cardiac risk index score classification of III or IV (37 per cent), surgery on major vessels, and surgery necessitated because of a complication of the ACBG itself (17 per cent). No correlation was found between cardiac complication rates and recurrent angina, hypertension, the use of beta-blockers or digoxin, or anaesthetic technique. It is suggested that all but emergency surgery should be postponed in the first month following ACBG, and elective surgery be delayed for up to six months.

Piriform syndrome

Among a variety of deep muscle trigger points, the piriform muscle trigger point is selected for individual scrutiny. This seems fully justified by the great potential for confusing this entity with discogenic disease and consequently having unnecessary surgical procedures carried out.The diagnosis can be made from findings on simple physical diagnostic tests and an appropriate history. Low back and hip pain with pain radiating down the back of the leg should suggest piriform syndrome as part of the differential diagnosis. This is especially true if a female patient has complaint of dyspareunia. Pain and weakness on resisted abduction-external rotation of the thigh is a sign of piriform syndrome. This is confirmed by tenderness and reproduction of the patient's complaints by digital pressure over the belly of the piriform muscle, completing the diagnostic criteria. Local injection of the muscle belly is curative. There are no laboratory or x-ray findings leading to a diagnosis.

A general method for the introduction of enzymes, by means of immunoglobulin-coated liposomes, into lysosomes of deficient cells

Phagocytes of the smooth dogfish (Mustelus canis) contain no endogenous peroxidase within their lysosomes and constitute models for cells genetically deficient in lysosomal enzymes such as myeloperoxidase. We have obtained uptake of over 50% of exogenous horseradish peroxidase, provided the enzyme is exhibited to cells after incorporation into liposomes coated with heat-aggregated (62 degrees, 10 min), isologous IgM. Trapping of horseradish peroxidase (EC 1.11.1.7) by liposomes was established by chromatographic resolution (Sephadex G-200; Sepharose 2B and 4B) of free enzyme from that associated with liposomes; liposome-associated horseradish peroxidase, together with trapped markers of the aqueous compartment (glucose, CrO4 equals), were excluded, and free enzyme and markers were retained. Enzyme and marker trapping was not electrostatic, varied with the molar ratio of charged membrane components, and was reversed by detergent lysis (Triton X-100) of liposomes. Uptake at 30 degrees of aggregated IgM-coated liposomes containing trapped horseradish peroxidase exceeded that of free enzyme of 100-fold, and was more efficient than uptake of horseradish peroxidase presented in uncoated liposomes or in liposomes coated with native IgM. After phagocytosis, peroxidase-rich liposomes were localized exclusively in lysosomes of the phagocytes by ultrastructural histochemistry; the enzyme displayed over 50% latency to osmotic lysis. This method may prove to be of general use in the provision of exogenous enzymes to phagocytic cells genetically deficient in lysosomal hydrolases.