An improved cathepsin-D substrate and assay procedure

Ten analogs of the peptide A-Phe(NO2)-Phe-Val-Leu-B were synthesized and tested as substrates for cathepsin D and pepsin. The best substrate found for cathepsin D, Phe-Ala-Ala-Phe(NO2)-Phe-Val-Leu-OM4P (kcat = 2.9 s-1; Km = 7.1 microM), has the largest kcat/Km value (408 mM-1 s-1) reported to date for this enzyme. The effect of peptide structure on solubility and kinetic parameters is discussed. The peptide provides a useful new substrate for continuous assay of cathepsin D.

Interaction of lanthanide cations and uranyl ion with the calcium/proton antiport system in Mycobacterium phlei

Uranyl ions (UO2+(2)) and lanthanide cations (La3+, Nd3+, Sm3+, Eu3+, Tb3+ and Dy3+) at 100-200 microM concentration inhibited active transport of Ca2+, mediated by respiratory linked substrates as well as by ATP hydrolysis, without affecting respiration and membrane-bound ATPase activity, in inside-out membrane vesicles of Mycobacterium phlei. The extent of inhibition in the uptake of Ca2+, mediated by ATP hydrolysis, increased with increase in ionic radii of these cations. Lanthanide cations did not dissipate the formation of a proton gradient, as measured by determining the effect either on the uptake of [14C]methylamine or energy-linked quenching of the fluorescence of 9-aminoacridine. However, uranyl ion (UO2+(2+)) caused reversal of the energy-linked quenching of 9-aminoacridine. UO2+(2)) concentration yielding 50% of Vmax (S0.5) was approx. 15 microM. Kinetic studies revealed that inhibition in the uptake of Ca2+ was competitive with UO2+(2) while non-competitive with rare-earth metals. It is proposed that inhibition in the uptake of Ca2+ by uranyl ion occurs as a result of UO2+(2) transport into the interior of vesicles in exchange for protons, while lanthanide cations are not being transported but affect the binding of Ca2+ to the membrane, presumably to the Ca2+/H+ antiporter.

Norethindrone in serum after use of an oral contraceptive containing norethindrone acetate

The availability of norethindrone (NET) in serum was studied in 8 women after daily administration of a combination oral contraceptive pill (MinovlarR) containing 1 mg norethindrone acetate (NETA) and 50 micrograms ethinyl estradiol (EE2) from day 5 to day 25 of the menstrual cycle. The pill was taken daily at 9:30 a.m. after a light breakfast and blood samples were collected at 3 hr on alternate days and at 24 hr on other days after ingestion of the pill. On day 12 or day 15 of the first treatment cycle, serial blood samples were also collected at 1/2, 1, 2, 4, 6, 8 and 24 hr after taking the pill. Serum NET levels were estimated by the radioimmunoassay (RIA) technique. The plot of serum NET concentration versus time (0-24 hr) profile showed a rapid absorption of steroid and a peak NET concentration (18.3 +/- 4.8 ng/ml) reached at 2 hr after ingestion of the pill. By linear regression analysis of data (y = 0.27 + 0.12x; r = 0.95), it was observed that the serum NET level was initially about 1 ng/ml. Thereafter, it increased by 0.12 ng/ml per day up to 3.5 ng/ml by the end of 21 days' treatment with oral pills. The serum NET concentration decay slope fitted a two-compartment open model with an initial rapid decay (half-life of 1.2 +/- 0.1 hr) followed by a slower beta-phase with a half-life of 8.5 +/- 1.5 hr. The study revealed that there was an accumulation of norethindrone in plasma during the treatment period and this suggests the possibility of exploring a reduction in the dose of this preparation so as to achieve the optimum NET concentration for contraception, and thereby avoiding unwanted steroid accumulation in the plasma of women.

Penetrating injuries of the neck: criteria for exploration

One hundred thirty-six patients with penetrating injuries of the neck over a 4-year period were studied prospectively. Seventy-two patients (52.9%) had no major physical signs on admission, 56 were observed without complications, and 16 had a negative exploration. Injuries below the level of the cricoid cartilage were associated with a very high mortality (12.12%). We recommend a policy of selective conservatism in the management of penetrating neck injuries.

Experience with 115 civilian venous injuries

Retrospective analysis of 115 patients with venous injuries managed at Lincoln Hospital in a 7-year period disclosed a total mortality of 15%. Retrohepatic caval injury was uniformly fatal; infrarenal caval injury was not. Fifty-six per cent of victims of truncal venoarterial injuries died. Isolated venous injury of the extremity was never lethal. Ligation of injured veins of the neck and upper extremities was well tolerated. Ligation of external iliac, or common femoral, or superficial femoral veins resulted in edema in 50% of the patients compared to 7% after repair (p less than 0.05). Venoarterial injuries of iliac or femoral-level veins resulted in 37% incidence of compartment syndrome against 5% in isolated arterial injuries (p less than 0.01). Therapeutic fasciotomy after the onset of clinically evident compartment syndrome did not prevent foot drop in any patient. We advocate that all major veins of the lower extremities be repaired with the same care as arterial injuries. Prophylactic fasciotomy for all patients with iliac or femoral venoarterial injuries should be considered as strongly as with popliteal venoarterial injuries. The caliber and patency of repaired veins must be assessed by venography at operation, and again before discharge from the hospital.

Hemodynamic and respiratory changes in surgery of the morbidly obese

The risk of surgery for the morbidly obese is well known. Suprisingly little information is available regarding the hemodynamic changes during surgery. This study provides data on this important subject and compares them with those of normal nonobese patients. Obese patients demonstrated signifying elevated preoperative, intraoperative, and postoperative right atrial, mean pulmonary artery, and pulmonary artery wedge pressures. Preoperatively, hemodynamic variables were in the high range of normal in obese patients. Significantly greater decreases in cardiac index, right ventricular stroke work (RVSW), and left ventricular stroke work (LVSW) were noticed intraoperatively. Although the RVSW returned to baseline values in the postoperative period, the cardiac index and LVSW remained depressed. Left ventricular function as assessed by Sarnoff curves demonstrated persistent shifts to the right during and after operation. No such shifts were noticed in nonobese patients. Although they were hemodynamically stable and without any other clinical evidence of cardiac abnormality, asymptomatic obese patients had reduced left ventricular contractility (LVSW/pulmonary artery wedge [PAW] pressure ratio) even in the resting state. Obese patients reacted to the stress of surgery and anesthesia by a more specific left ventricular dysfunction that was greater after intubation and in the immediate postoperative period.

Microfilariae in association with neoplasms. Report of six cases

Microfilariae were observed during routine cytopathologic or histopathologic examination of tumor tissue from six neoplasms. Subsequent to the detection of the parasite in smears or sections, repeated examination of night blood smears from these patients demonstrated microfilariae in only one case of squamous-cell carcinoma of the cervix. Histopathologic examination of the serial sections revealed different types of unrelated tumors, but no microfilariae could be demonstrated except in one case of hemangioblastoma of the cerebellum.

Evaluation of sulprostone for second trimester abortions and its effects on liver and kidney function

Sulprostone was given intramuscularly in two dose schedules of 0.5 mg at 4 hourly intervals for 8 doses and 1.0 mg at 8-hour intervals for 4 doses to 56 women in the 12th-20th week of gestation coming for termination of pregnancy. Forty-nine of them aborted within the 30-hour observation period, giving a success rate of 87.5%. Within the observation period, the induction-abortion interval with the 0.5-mg schedule was 16.6 hours while the interval with the 1.0-mg schedule was 15.4 hours. Side effects caused by the drug were minimal and it was observed that patients receiving 1.0 mg Sulprostone had slightly more side effects per person than in those cases receiving 0.5 mg Sulprostone. Serum parameters assessing liver and kidney functions were carried out in 48 patients prior to, 24 hours later and two weeks after the abortion. There were significant changes in the levels of uric acid, potassium, serum proteins and SGOT, though these changes were within the normal range.

Acute dieldrin toxicity: effect on the uptake of glucose and leucine and on brush border enzymes in monkey intestine

Administration of a single oral dose of dieldrin (20 mg/kg body wt.) to rhesus monkeys considerably elevated the uptake of glucose and the activities of brush border sucrase, lactase, maltase and alkaline phosphatase in intestine compared to control animals. Leucine uptake and leucine amino peptidase activity was significantly depressed in pesticide-treated animals. Kinetic studies with brush border sucrase revealed that augmentation of enzyme activity in pesticide-fed animals was due to an increase in the disaccharidase content.

Myocardial function in acute pancreatitis

Fifteen patients with acute pancreatitis had 68 physiologic cardiopulmonary assessments performed, and they were compared with 61 performed on normal postoperative patients, and 113 on 41 cirrhotics. It was found that the patients with pancreatitis have an elevated cardiac index (CI), which is not due to the hyperdynamic hemodynamic state found in cirrhotics. In spite of this, the Sarnoff curves demonstrated that pancreatitis was accompanied by a myocardial depression p less than 0.03, not found in hyperdynamic cirrhotics. Cirrhotics are unable to increase their oxygen consumption in response to an increase in CI, as do normal patients or those with acute pancreatitis. In cirrhotics the hemodynamic lesion occurs at the capillary level with the opening of arteriovenous shunts which rob the tissues of their nutritive blood supply, while the patient with acute pancreatitis has a primary myocardial depression and his peripheral vasculature reacts like that of a normal person.

Effect of a single oral dose of DDT on lipid metabolism in rat

A single oral dose of 1,1,1-trichloro-2-2-bis (p-chlorophenyl)ethane (DDT) (600 mg/kg body weight) was given to rats and the levels of various lipids in adipose tissue, liver and plasma were studied. No alteration was observed in the levels of various lipid classes in these tissues except for a decrease in the phospholipid and triglyceride fractions in liver. Lipoprotein lipase activity of post-heparin plasma (protamine-sensitive and -resistant) was significantly decreased, whereas in liver and adipose tissue, the activity of this enzyme remained unchanged.

Acute exposure of rhesus monkeys to DDT: effect on carbohydrate metabolism

The administration of a single oral dose of DDT (150 mg/kg body wt.) to rhesus monkey elevated the hepatic glycogen and glycogen synthase activity but depressed the glycogen phosphorylase activity. A decrease in adenylate cyclase, both basal as well as fluoride and norepinephrine stimulated activity, was observed in liver of DDT-treated animals as compared to controls. Gluconeogenic enzymes did not record any significant change in the liver.

The sterols of the khapra beetle, Trogoderma granarium Everts

The khapra beetle, Trogoderma granarium Everts, does not dealkylate and convert dietary C28- or C29-Phytosterols to C27-sterols such as cholesterol. There is, however, an increase in the concentration of cholesterol and campesterol in its tissues relative to the dietary concentrations of these sterols, presumably as a result of selective uptake.

Radioimmunoassay of norethindrone : serum levels of norethindrone in lactating women after insertion of a single Silastic implant releasing norethindrone acetate

A specific radioimmunoassay was developed for the estimation of norethindrone levels in the serum of lactating women. A conjugate of norethindrone-3-BSA was synthesized and antiserum raised against it in rabbits. The antiserum showed high affinity (1.5 x 10(9)M/L) and titer and was specific. The sensitivity of the assay was 125 pg/ml serum. Serum levels of norethindrone were estimated in 25 lactating women, inserted with subdermal implant releasing about 150 ug of norethindrone acetate daily. The norethindrone levels were initially high in the first two months. From there onwards the levels of norethindrone remained constant with an average value of 1.0 ng/ml up to six months. These values were comparable to those obtained in non-lactating women. Thus, lactation does not seem to alter or affect the release of norethindrone acetate from the subdermal implant or its metabolism.

Effects of DDT (chlorophenotane) administration on glucose uptake and brush border enzymes in monkey intestine

A considerable increase occurs in D-glucose uptake and brush border sucrase and lactase activities in the intestine of monkeys treated with a single oral dose of DDT. Brush border alkaline phosphatase activity remains unaffected in the pesticide treated animals. In vitro addiction of DDT has no effect on the sugar absorption and disaccharidase activities.

Effect of chronic alloxan diabetes and insulin administration on intestinal brush border enzymes

Brush border sucrase and lactase activities are significantly elevated in alloxan-induced chronic diabetes and are restored to control levels after insulin treatment. Alkaline phosphatase and Mg-ATPase levels remain unchanged in diabetes, compared to a control group. Insulin treatment alone to control animals also led to enhanced activities of these enzymes.