Lipophilic 5'-(alkyl phosphate) esters of 1-beta-D-arabinofuranosylcytosine and its N4-acyl and 2,2'-anhydro-3'-O-acyl derivatives as potential prodrugs

Lipophilic 5'-(alkyl phosphate) esters of 1-beta-D-arabinofuranosylcytosine (ara-C) and several N4-acyl and 3'-O-acyl-2,2'-anhydro derivatives of ara-C were synthesized as potential prodrugs of ara-C 5'-monophosphate (ara-CMP). Alkylphosphorylation of ara-C, N4-palmitoyl-ara-C, and N4-stearoyl-ara-C was achieved in a single continuous operation by allowing the nucleoside to react with POCl3 in trimethyl or triethyl phosphate and adding the appropriate anhydrous alcohol directly to the intermediate phosphorodichloridate without isolation. Similar reaction of cytidine yielded cytidine 5'-(alkyl phosphate) esters, which on treatment with myristoyl or palmitoyl chloride in the presence of boron trifluoride gave 3'-O-acyl-2,2'-anhydro-ara-C 5'-(alkyl phosphate) esters. Ara-C 5'-(n-butyl phosphate) (1b), N4-palmitoyl-ara-C 5'-(n-butyl phosphate) (1h), and 2,2'-anhydro-3'-O-palmitoyl-ara-C 5'-(n-butyl phosphate) (2h) were tested against L1210/ara-C leukemia in mice in the hope that this kinase-deficient tumor would respond to treatment with these "prephosphorylated" derivatives, but no activity was observed. Of the simple 5'-(alkyl phosphate) esters tested in culture against l1210 leukemic cells, only ara-C 5'-(glyceryl phosphate) (1g) showed toxicity comparable to ara-CMP (ID50 = 0.35 and 0.65 microM, respectively), suggesting that beta-hydroxyalkyl phosphate esters may be worthwhile to examine further as prodrugs of ara-CMP.

Preliminary crystallographic studies of a sweet protein, monellin

Monellin belongs to a new class of proteins that have intensely sweet taste. We report here the results of crystallization of this protein and crystallographic parameters of the monellin crystals; space group is P21; the cell parameters are 39.1 X 71.5 X 86.9 A with beta = 107.6 degrees; and there are 4 monellin molecules/asymmetric unit.

Repair of mild hypospadias

A one stage repair is presented for mild hypospadias with or without chordee, entailing a local flap of shaft skin rotated forward to the tip of the glans and tubularized. The two halves of the glans penis are brought together to enclose the neourethra. This procedure results in a normal appearing penis. In 50 cases complications were limited to two meatal stenoses. There were no fistulas. This procedure is not used in cases with greater than minimal deformity.

Sensory conduction study of distal radial nerve

The technique of recording superficial radial sensory nerve action potential (SNAP) from the thumb was compared with that of recording from the 1st web space. The spread of stimulus to the median nerve in the forearm when stimulating the radial sensory nerve with relatively high intensity was also investigated. Recording the radial SNAP from the 1st web space produces a larger amplitude response with a sharper takeoff point compared with that of recording from the thumb. Furthermore, with the former technique, the radial SNAP is uncontaminated by a component arising in the median distribution which makes interpretation of its configuration more reliable.

Synthesis and antitumor activity of an acyclonucleoside derivative of 5-fluorouracil

The pyrimidine acyclonucleoside 5-fluoro-1-[(2-hydroxyethoxy)methyl]uracil (3) was synthesized as part of a program aimed at the development of new 5-fluorouracil derivatives with fewer side effects and a broader margin of safety. Condensation of 5-fluoro-2,4-bis[(trimethylsilyl)oxy]pyrimidine with 2-acetoxyethyl acetoxymethyl ether (6) in the presence of SnCl4 afforded the acetate ester 7, which on deprotection with NaOMe gave 3 in 50-60% overall yield. The 5-bromo and 5-iodo analogues 10 and 11, respectively, were obtained similarly. Reaction of 5-fluoro-4-(methylthio)-2-[(trimethylsilyl)oxy]pyrimidine with 2-acetoxyethyl acetoxymethyl ether and SnCl4, followed by ammonolysis, yielded 5-fluoro-1-[(2-hydroxyethoxy)methyl]cytosine (12). Deamination of 12 with nitrous acid produced 3, thereby confirming that alkylation of 5-fluoro-2,4-bis[(trimethylsilyl)oxy]pyrimidine had occurred at N1. The ID50 of 3 against L1210 mouse leukemia cells in culture was 1.7 x 10(-5) M, as compared with 1 x 10(-6) M for FU. The 5-fluorocytosine analogue 12 was inactive at up to 1 x 10(-4) M, and the other halogenated derivatives 10 and 11 had no effect even at 1 x 10(-3) M. When 3 was given ip in water to P388 leukemic mice at 400 mg/kg (b.i.d. x 4) or 240 mg/kg (q.d. 1-9), a 75% increase in survival was observed relative to untreated controls, and there was no evidence of any host toxicity.

Methotrexate serum and saliva concentrations in patients

Serum and mixed saliva concentrations were determined in two patients upon i.v. injection of methotrexate. The concentration-time profiles were followed up for 100 h after dosing. Whereas no correlation was found between serum and saliva concentrations for the first 15 h, which corresponds with the distribution phase of methotrexate, a correlation was found for the terminal phase with a serum-saliva ratio of 3.8. The volume of distribution for the central compartment was approximately equal to the serum volume. The apparent volume of distribution was close to the total body fluid volume.

Absence of correlation between base-pair sequence and RNA conformation

A survey of all available double-stranded RNA crystal structures shows that there is a considerable range of variation in local conformation of a given base-pair doublet, but that there is no significant correlation between base-pair sequence and RNA local conformation.

Choledochal cyst: survey by the surgical section of the American Academy of Pediatrics

Choledochal cyst is a rare surgical condition that requires prompt surgical treatment to prevent biliary cirrhosis and portal hypertension. The results in this series indicate that the preferred surgical management is: (A) cyst excision and anastomosis of the common bile duct to a Roux-en-Y jejunal loop or (B) direct anastomosis of the "cyst" to a Roux-en-Y jejunal loop. A higher long-term complication rate was seen in patients after direct anastomosis of the duodenum to the adjacent "cyst." Choledochal cyst with biliary atresia probably represents an operable form of extrahepatic bile duct atresia. Of 22 patients with biliary atresia, 11 are living and well without liver disease. The importance of early surgical attention cannot be over emphasized.

Crystallization and preliminary X-ray diffraction studies of an inactive mutant aspartate transcarbamoylase from Escherichia coli

A mutant aspartate transcarbamoylase, ATCase231, has been crystallized at neutral pH. The mutant enzyme has a single substitution of aspartic acid in place of glycine within the catalytic chain and shows not only the loss of enzyme activity but also marked changes in the chemical reactivity of several amino acid residues and weakening of interaction between regulatory and catalytic subunits. Despite these differences, the mutant enzyme crystals have the same space group and cell parameters as the wild type crystals grown at pH 5.9.

Effect of warfarin on survival in small cell carcinoma of the lung. Veterans Administration Study No. 75

In a controlled, randomized study, survival of patients with small cell carcinoma of the lung (SCCL) was prolonged on addition of warfarin sodium to combination chemotherapy plus radiation therapy. Median survival for 25 control patients was 24 weeks and for 25 warfarin-treated patients was 50 weeks. This difference could not be accounted for by differences between groups in performance status, extent of disease, age, or sex. The survival advantage associated with warfarin administration was observed both for patients with extensive disease and for those who failed to achieve complete or partial remission. The warfarin-treated group also demonstrated a significantly increased time to first evidence of disease progression. These results suggest that warfarin may be useful in the treatment of SCCL and also support the hypothesis that the blood coagulation mechanism may be involved in the growth and spread of cancer in man.

Progestin permeation through polymer membrane V: Progesterone release from monolithic hydrogel devices

Progesterone release from monolithic devices prepared from various copolymers of poly(hydroxyethyl methacrylate) and poly(methoxyethoxyethyl methacrylate) or poly(methoxyethyl methacrylate) was examined. In general, plots of the fraction of drug released versus (time)1/2 were linear during the early stages of drug release. This behavior is similar to that found for drugs released from hydrophobic polymers such as polydimethyl siloxane. However, for some release curves using the hydrogels, a breakpoint appeared during the early stages of drug release. These breakpoints were due to the effects of water absorption by these polymers. From analyses of permeability coefficients, it was demonstrated that release rates also were dependent on the initial drug load and the equilibrium water content of the polymer. These conclusions were verified from cross-membrane diffusion studies on films depleted of their initial drug load. In conjunction with this work, the aqueous solubility of progesterone was determined by several methods; an average value of 38 micrograms/ml at 23 degrees was obtained.

A protein fraction (NHG) from serum of normal humans which is cytotoxic for HeLa cells in culture

A fraction of the alpha-globulins (NHG) from normal human serum was cytotoxic for mouse L-cells in culture and Meth A tumors in mice. NHG inhibited the growth in vitro of human colon cancer (HT-29), melanoma (RPMI 7931) and a neuroblastoma cell line. Survival of HeLa S-3 cell colonies after 24 h exposure to 25, 50, 75 or 100 micrograms NHG/ml medium was 86%, 77%, 40% and 10%, respectively. Whole human serum or purified serum albumin had no anti-HeLa cell activity. These results confirm the presence of a protein in human serum with antitumor activity. An assay for NHG using HeLa S-3 tumor cells is described.

The inferior epigastric vein as an alternate site for central venous hyperalimentation

The inferior epigastric vein is a good access site when central venous nutrition cannot be delivered through the usual routes. The babies can remain mobile without angulating the catheter and, by tunneling above the diaper line, contamination can be avoided.

Selective killing of glucose and oxygen-deprived HeLa cells by hyperthermia

We previously have reported that glucose deprivation specifically enhance cell killing by hyperthermia in the absence of oxygen. The present studies were carried out to evaluate the interplay of glucose and oxygen on cell killing by hyperthermia (37 to 42 degrees) for up to 4 hr under varying concentrations of glucose (0 to 1 mg/ml) and oxygen (0 to 21%). pH 7.4 was maintained in all trials. In the absence of oxygen, enhanced cell killing at 40 and 42 degrees was seen with glucose concentrations below 0.1 and 0.25 mg/ml of media, respectively. In the absence of glucose, enhanced killing was seen when oxygen concentrations were below 1 and 2% at 40 and 42 degrees, respectively. The radiosensitivity of the cells was influenced only by the oxygen concentration during irradiation and not by glucose. These results indicate that oxygen and glucose are important modifying factors of cell lethality by hyperthermia.

Conformationally restricted phenothiazine neuroleptics. 1. 3-(Dimethylamino)-1,2,3,4-tetrahydroazepino[3,2,1-kl]phenothiazine

A rigid analogue of promazine, 3-(dimethylamino)-1,2,3,4-tetrahydroazepino[3,2,1-kl]phenothiazine (1), was prepared by reductive amination of the corresponding ketone 4. An X-ray crystallographic study revealed that the seven-membered ring of the hydrochloride salt of 1 exists as a half-chair-like form with the dimethylammonium group in an equatorial-like conformation. Compound 1 was approximately one-half as active as promazine as an inhibitor of [3H]spiperone binding in rat corpus striatal homogenates. In homogenates obtained from calf caudate tissue, however, 1 was only about one-twentieth as active as promazine as an inhibitor of [3H] spiperone binding. As a stimulator of homovanilic acid (HVA) synthesis in rat corpus striatum in vivo, it was about one-tenth as active as promazine.

Gastroesophageal reflux and hiatus hernia in children: experience with 70 cases

Seventy cases of gastroesophageal reflux with or without hiatus hernia were operated upon since 1959. The technique described herein was used in the majority of cases with satisfactory results.

Diagnosis and treatment of cannula-related intravenous sepsis in burn patients

Suppurative thrombophlebitis was identified in 193 (4.2%) of 4,636 burn patients treated during the years 1960-1978. A single vein was involved in 162 patients, while 31 had multiple vein involvement. The distribution and incidence of suppuration in individual veins reflected the frequency of cannulation, with an increase in the use of central vein cannulae, during the last 10 years, paralleled by a rise in central vein suppuration. The infecting organisms reflected the patients' surface flora. Local signs of infection were present in less than half (35%) of the patients and recovery of a positive blood culture in a clinically septic patient was the most frequent clinical presentation prompting exploration of previously cannulated veins. Pathogenetic mechanisms are identified and criteria defined for determining the extent of excision necessary. Ninety veins were excised from 75 patients during the 1969-1978 period, of whom 30 (40%) survived (three other patients with antibiotic treated central vein disease also survived). Treatment failure was attributable to inadequate excision in 12 patients, suppuration within another unexcised vein in eight patients, hematogenous dissemination of infection in five patients in whom the local disease had been eradicated, and other disease in 20 patients. Prophylaxis must emphasize limited duration of cannulation. Timely diagnosis and treatment can effect maximum salvage and reduce the likelihood of systemic dissemination.

Structural analogues of L-glutamic Acid gamma-(4-hydroxyanilide) and gamma-(3,4-dihydroxyanilde) as potential agents against melanoma

Nine heretofore unknown mono- and dihydroxyanilide analogues of the cytotoxic mushroom metabolites L-glutamic acid gamma-(4-hydroxyanilide) (1) and L-glutamic acid gamma-(3,4-dihydroxyanilide) (3, agaridoxin) were synthesized and tested as inhibitors of the growth of B16 mouse melanoma cells in culture. The naturally occurring anilides 1 and 3 had ID50 values of 0.10 and 0.27 mM, respectively. The analogue of 1 in which the gamma-L-glutamyl moiety was replaced by beta-L-aspartyl showed only a threefold decrease in activity, whereas attachment of the phenolic OH group to the meta instead of the para position resulted in a tenfold decrease. Other structural modifications, such as O-methylation or deletion of the carboxyl or amino group in the side chain, led to compounds of still lower activity (ID50 greater than 1.0 mM). The only analogue in the series with more activity than either 1 or 3 against B16 cells was L-glutamic acid gamma-(2,5-dihydroxyanilide) (14), which had an ID50 value of 0.051 mM. These data suggest that the gamma-L-glutamyl side chain in 1 or 3 plays a significant role in the biological action of these compounds, though some flexibility appears to exist insofar as the positioning of OH groups on the aromatic ring is concerned.

Imidazo[1,2-a]-s-triazine nucleosides. Synthesis and antiviral activity of the N-bridgehead guanine, guanosine, and guanosine monophosphate analogues of imidazo[1,2-a]-s-triazine

The first chemical synthesis of 2-aminoimidazo[1,2-a]-s-triazin-4-one (8), the corresponding nucleoside and nucleotide, and certain related derivatives of a new class of purine analogues containing a bridgehead nitrogen atom is described. Condensation of 2-amino-4-chloro-6-hydroxy-s-triazine (2) with aminoacetaldehyde dimethyl acetal followed by the ring annulation gave the guanine analogue 8. A similar ring annulation of 4-(2,2-dimethoxyethylamino)-s-triazine-2,6-dione (5) gave imidazo[1,2-a]-s-triazine-4,6-dione (9). Direct glycosylation of the trimethylsilyl derivative of 8 with 1-O-acetyl-2,3,5-tri-O-benzoyl-beta-D-ribofuranose in the presence of stannic chloride, followed by debenzoylation, gave the guanosine analogue 2-amino-8-(beta-D-ribofuranosyl)imidazo[1,2-a]-s-triazin-4-one (12b), which on deamination gave the xanthosine analogue 13. Phosphorylation of 12b gave 2-amino-8-(beta-D-ribofuranosyl)imidazo[1,2-a]-s-triazin-4-one 5'-monophosphate (II). The anomeric configuration has been determined unequivocally by using NMR of the 2',3'-O-isopropylidene derivate 10 and the site of ribosylation has been established by using 13C NMR spectroscopy. These compounds were tested against type 1 herpes, type 13 rhino, and type 3 parainfluenza viruses in tissue culture. Moderate rhinovirus activity was observed for several compounds at nontoxic dosage levels.

Selective potentiation of hyperthermic killing of hypoxic cells by 5-thio-D-glucose

The modification of cell lethality at elevated temperatures by 5-thio-D-glucose, the nearest analog of D-glucose was studied with the use of HeLa cells in the presence or absence of oxygen. When the cells were exposed to temperatures ranging from 40.5-42 degrees for 0.5 to 4 hr in the presence of 5-thio-D-glucose (5 mM), there was a selective potentiation of hyperthermic killing of hypoxic cells. No enhanced killing of oxic cells by 5-thio-D-glucose was seen at these temperatures. These results indicate that glucose metabolism may be involved in influencing the heat sensitivity of hypoxic cells. The low toxicity of 5-thio-D-glucose and its specificity to hypoxic cells suggest that it may be a useful adjuvant to hyperthermic therapy.

5-Thio-D-glucose selectively potentiates hyperthermic killing of hypoxic tumor cells

To investigate the mechanisms by which heat affects cancer cells, we used 5-thio-D-glucose, an inhibitor of glycolysis in HeLa S-3 cells, under aerobic and hypoxic conditions at temperatures ranging from 37 degrees to 43 degrees C. Drug alone or heat alone killed a minimum number of cells under aerobic or hypoxic conditions. Exposure to drug and hyperthermia selectively increased the number of cells killed under hypoxic conditions at temperatures as low as 40.5 degrees C but had little effect on cells incubated under aerobic conditions. These results suggest that the glycolytic pathways is a primary site of hyperthermic damage leading to cell death.

alpha-Helix-double helix interaction shown in the structure of a protamine-transfer RNA complex and a nucleoprotamine model

Single crystal X-ray diffraction and circular dichroism studies of protamine binding to a tRNA suggest that the protamine molecule changes its conformation from a random coil to a structure containing a helices on binding to tRNA, and that alpha-helical segment(s) of protamine bind approximately along a shallow groove of a double-helical portion of ttrna. based on these observations, a structural model for nucleoprotamine is proposed.

Sexual precocity in a male due to thoracic polyembryoma

A 7-year-old boy with sexual precocity of recent onset was found to have elevated levels of chorionic gonadotropin, alpha fetoprotein, and testosterone. Removal of a retropleural, posterior mediastinal mass with an intraspinous epidural extension was followed by prompt declines in the plasma concentrations of the tumor markers and cessation of adolescent development. The neoplasm proved to be a polyembryoma, unusual in the multiplicity of its embryoid bodies and extra gonadal location. Following local irradiation and two years of systemic chemotherapy, the patient, now 13 years of age, has done well except for evidence of testicular tubular insufficiency.

Effect of dietary restrictions and source of rats on growth rate and efficiency of conversion of food into muscles, bones and organs

Differences in weight of the body, six different skeletal muscles, epididymal fat pads, three different bones, spleen, heart, kidneys, testes and liver were observed in 21-day-old male Sprague-Dawley rats from two different suppliers. All rats were pair-fed a 10% casein diet ad libitum, 10%, 20%, 30% restricted for 4 or 8 weeks. Original body and tissue weight differences between the two strains of rats were maintained in all diets during the 4 and 8 week feeding periods. Trends in body and tissue weight changes due to dietary restriction were similar in both strains of rats. Diet restrictions for 4 or 8 weeks caused similar patterns of weight decrease in most tissues. Feed efficiency ratio (FER) was reduced significantly at the 20% and 30% restriction for 4 weeks only in the lighter strain of rats. FER was higher in the heavier strain than in the lighter strain of rats at all levels of diet restriction. Food conversion efficiency with reduced food intake was constant or decreased depending on the skeletal muscle studied; decreased significantly for epididymal fat pad, bone weight (one strain only), kidneys and liver (one strain only) with the 30% reduced diet for 4 weeks; and increased for bone length and testes weight. Therefore, significant deviations from ad libitum controls were found only at 30% diet restriction, and the wide differences in body and tissue weight of two strains of Sprague-Dawley rats did not affect the interpretation of results when fed the same restricted diets.

RNA-ligant interactions. (I) Magnesium binding sites in yeast tRNAPhe

X-ray crystallagraphic studies studies indicate that there are at least four site-specifically bound hydrated Mg2+ ions, [Mg(H2O)n]2+, in yeast tRNAPhe. The size and the octahedral coordination geometry, rather than the charge, of [Mg(H2O)N]2+ appear to be the primary reasons for the specificity of magnesium ions in site-binding and in the stabilization of the tertiary structure of tRNA.

Secondary structural complementarity between DNA and proteins

A model for the complex between double-stranded DNA and a beta-ribbon (a two-stranded antiparallel beta-sheet) of proteins is proposed as one of the possible modes of structural recognition between DNA and proteins. In this model, the contact occurs on the narrow groove of DNA, and the symmetry elements as well as the repeat distances of DNA and the beta-ribbon coincide, thus providing favorable complementary contacts.

Endoscopic resection of obstructing airway lesions in children

In the past 8 yrs, 14 children were treated with obstructing lesions of the larynx, some of then acquired from prolonged intubation. Endoscopic resection of the obstructions proved feasible in selected cases. The use of a wire stylette of fine needle within a small ureteral catheter sheath provides a readily available and accurate means for dealing with some of these lesions.

Omphalocele

From a historical curiosity at the turn of the century, today omphalocele and gastroschisis can be corrected with good results, thanks to innovative techniques and better understanding of the newborn. Associated anomalies consist mainly of malrotation, Meckel's diverticulum, intestinal atresia, congenital heart defects, and genitourinary abnormalities. Nonoperative management in certain centers has been sucessful for the very large omphaloceles with an intact sac; however, a secondary procedure is necessary. In the past 10 years, the use of Silastic sheeting and total parenteral nutrition has allowed early repair of even the most severe cases, with excellent end results and low mortality.

Plasma chromatography of heroin and cocaine with mass-identified mobility spectra

Plasma chromatography detects and identifies compounds in trace quantities at atmospheric pressure through characteristic positive and negative mobility spectra. To facilitate use of the technique to detect gas chromatographic effluents, a number of reference mobility spectra for different classes of compounds have been reported. Reference spectra for two more compounds, heroin and cocaine, are presented in this study. The primary ions found in these mobility spectra were determined to be M+, (M - H2)+, and (M - CH3CO2)+ for heroin and M+, (M - C6H5CO2)+ and (M - C6H5CO2 - CO2CH3)+ for cocaine using a directly interfaced plasma chromatograph-mass spectrometer. The identified ions agree closely with those predicted in the ion mobility spectra using mass-mobility correlation data coupled with chemical ionization mass spectrometry data. Also, an independent check demonstrating the reliability of reduced mobility values reported in earlier reference spectra was made.