Cytomegalovirus transmission to extremely low-birthweight infants through breast milk.

AIM: To determine the incidence, timing and clinical significance of acquired postnatal cytomegalovirus (CMV) in extremely low-birthweight (ELBW) infants. METHODS: Prospective, longitudinal surveillance study. ELBW infants were recruited in the first week of life. Maternal blood was tested for CMV-specific IgG antibodies. Weekly urine samples were obtained from infants for CMV culture and rapid antigen testing. Data were collected regarding clinical course and breast milk intake. RESULTS: Of 181 eligible infants, 119 infants, born to 101 mothers, were enrolled. Eighty of the 101 mothers had their serum checked for CMV status. Seventy percent of those tested were seropositive for CMV. Of the 65 infants born to seropositive mothers, 94% received breast milk during their hospital stay. Complete urine collection was obtained in 92 infants. CMV was cultured from the urine of only four infants, all of whom were born to seropositive mothers. Only one of these four infants was symptomatic. The range at which CMV was first detected was between 48 and 72 postnatal days of age. CONCLUSIONS: Despite a very high CMV seropositivity rate in mothers of ELBW infants, and the previously reported high rate of CMV excretion into breast milk, the incidence of postnatal CMV transmission was extremely low in our study.

Coexpression of Bcl-2, c-Myc, and p53 oncoproteins as prognostic discriminants in patients with colorectal carcinoma.

PURPOSE: This study was undertaken to evaluate the clinical use of Bcl-2, c-Myc, and p53 oncoproteins, either singly or in combination, as prognostic discriminants relative to recurrence and overall survival in patients with Dukes B or C colorectal carcinoma. METHODS: Analyses were made on archival pathology tissues of 48 patients with colorectal cancer. The oncoproteins were localized using commercially available monoclonal antibodies: clone 124 for Bcl-2, 9E11 for c-Myc, and DO-7 for p53. The avidin-biotin peroxidase complex method was used. Patients were followed up for a period of 2 to 36 months. RESULTS: Expression of Bcl-2 and c-Myc was cytoplasmic, whereas nuclear p53 immunoreactivity was localized in the tumor cells. Sixty percent (29/48), 65 percent (31/48), and 37 percent (18/48) of the tumors showed overexpression of Bcl-2, c-Myc, and p53 oncoproteins, respectively. Fifty-four percent (18/33) and 100 percent (9/9) of moderately and poorly differentiated tumors, respectively, were positive for Bcl-2 (P < 0.01). No such correlation was noted for c-Myc and p53 oncoproteins. Univariate analysis showed that patients with Bcl-2 and c-Myc overexpression were associated with poorer overall survival than patients with Bcl-2-negative (P < 0.0124) and c-Myc-negative (P < 0.036) tumors. In addition, when patients were subgrouped according to Dukes stage, a statistically significant poorer overall survival was observed in Dukes C patients with Bcl-2-positive tumors (P < 0.017). Furthermore, multivariate analysis revealed that coexpression of three oncoproteins was predictive of a worse prognosis than for those individuals expressing none of the oncoproteins (P < 0.031) and only one positive oncoprotein (P < 0.014). CONCLUSION: These findings suggest that oncoprotein coexpression possesses significant prognostic and potential therapeutic value; incorporation of molecular markers into future prospective randomized trials is advisable.

Can plasma prolactin predict tamoxifen resistance in patients with advanced breast cancer?

The antiestrogen tamoxifen (TAM) is an effective therapy for advanced breast cancer. However, its use is limited by the eventual development of acquired TAM resistance in many patients. There is now strong evidence to suggest that prolactin plays an important role in advanced breast cancer. We have measured plasma prolactin (PRL) and estrogen-receptor (ER) and progesterone-receptor (PR) in post-menopausal patients with breast cancer (Stage III, n = 44). The blood samples were collected pre-operatively and sequentially thereafter for a minimum period of 3 years or until the death of the patients. The ER and PR were estimated in breast tumor samples by dextran-coated charcoal (DCC) method. The patients were treated with surgery and radiotherapy followed by TAM (10 mg, 1 BD). Based on the response to treatments, the patients were divided into two groups: (1) TAM sensitive (n = 19) and (2) TAM resistant (n = 25). In the TAM sensitive group, patients responded to the treatment and did not develop progressive disease within a period of 3 years. On the contrary, in the group of TAM resistant, patients developed progressive disease within a period of 3 years. The development of progressive disease clearly indicated TAM resistance. Plasma PRL correlated well with the disease progression. This study clearly demonstrated that plasma prolactin accurately indicated the response and development of resistance to TAM in patients with advanced breast cancer.

Circulating epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) in patients with epithelial ovarian carcinoma.

Circulating epidermal growth factor (EGF) and insulin-like growth factor-I (IGF-I) were estimated in 58 patients with epithelial ovarian cancer and were correlated with clinically and biochemically important prognosticators. IGF-I levels were significantly low in patients as compared to controls. The relation of growth factors with clinically important prognosticators was non-significant. Moreover, the levels of EGF and IGF-I in the ER+/PR+ and ER-/PR- groups and in the low and high EGFR+ tumors did not differ significantly. Patients with EGF < 1.0 ng/ml had significantly better survival than those with EGF > 1.0 ng/ml.

Hormones in male-patients with advanced esophageal-carcinoma.

Hormones are believed to play a dominant role as promoters in the growth and development of hormone-dependent cancers. Much less is known about the circulating hormones in male patients with oesophageal cancer. This lack of attention led us to evaluate the role of peptide and steroid hormones (by RIA) in male patients with oesophageal cancer (n=49). Blood samples of patients were collected pretherapeutically and data was compared with age matched controls (n=25). In this retrospective study, significantly high levels of FSH (P<0.02), LH (P<0.001) and prolactin (P<0.001) were observed with concomitant low levels of estradiol (P<0.001), DHEA-S (P<0.02) and testosterone (P<0.001) in patients when compared with respective controls. The patients when grouped according to anatomical site and histological type of the tumor, intergroup variation was not observed in these hormones. From our, study, it seems that hormonal imbalance or altered ratio of peptide and steroid hormones might be playing a significant role in the development and/or progression of oesophageal carcinoma in men.

Effect of trimethyltin on hepatic and extra-hepatic non-protein sulfhydryl levels in the mouse.

Administration of trimethyltin (TMT) ip to mice lowered non-protein sulfhydryl (NPSH) levels in a tissue-specific and dose-dependent manner. Incubation of TMT with GSH and mouse hepatic cytosol did not result in conjugation of TMT, as evidenced by the lack of reduction of GSH levels. Additionally, TMT in vivo did not increase oxidized glutathione (GSSG) levels, nor did it alter hepatic ATP content. These results suggest that TMT decreased NPSH levels in vivo by either directly inhibiting GSH synthesis or by inhibiting uptake of precursor amino acids.

Distribution of trimethyltin in various tissues of the male mouse.

Trimethyltin (TMT) levels were determined in various tissues of male mice at 1, 2, 4, 6, 10 and 16 h after administration (4.26 mg/kg; i.p.). Peak TMT levels in kidneys, liver, blood, lungs and testes were observed at 1 h following administration. Penetration into the brain, skeletal muscle and adipose tissue was also observed where maximum TMT levels were achieved 6-16 h following administration. 16 h post-treatment, the order of mean tissue concentrations, of the compound was: liver greater than testes greater than kidneys greater than lungs greater than brain greater than skeletal muscle greater than adipose tissue greater than blood. TMT was retained at peak levels in most tissues until, by 16 h, the animals exhibited tremors and convulsions followed by death. The mean concentration of TMT in the brain associated with delayed (central nervous system) (CNS) excitability at 16 h was 1.53 micrograms/g of wet tissue. These results indicate that TMT rapidly distributes and, although water-soluble, persists in tissues following an i.p. administration.

Triethyltin decreases maximal electroshock seizure severity in adult rats.

Acute and subacute treatment of adult rats with triethyltin bromide (TET) caused dose-dependent and time-dependent decreases in maximal electroshock seizure (MES) severity. This decrease in excitability was characterized by both a decrease in the percentage of animals exhibiting a maximal seizure and a corresponding decrease in the extension durations and an increase in the flexion durations. Acutely treated rats received (ip) 0, 1, or 5 mg/kg TET while subacutely exposed (po) received 0, 1, 5, or 10 ppm TET in the drinking water for 10 days. Experiments were designed so that the total consumed dose of TET, on a milligram per kilogram basis, equaled that in the acute experiment. No alterations in body weight were observed in either experiment. Acutely, the onset of action of TET was detectable within 0.5 hr. For the 1 mg/kg group, the effect peaked between 4 and 24 hr and completely recovered by 72 to 96 hr. For the 5 mg/kg group, the marked effect peaked at 4 hr, however, no recovery was observed. Subacute exposure for 1 to 2 days produced marked decreases in MES severity which were still present in the 5- and 10-ppm groups 14 days after cessation of exposure. Comparison of the onset and recovery data in the acute and subacute experiments revealed a close correspondence in similarly dosed rats. Comparison with other MES data from our laboratory revealed that adult rats were more sensitive to TET than adult mice or developing rats. Additionally, the MES test was able to detect subtle functional alterations in the central nervous system at lower doses of TET than previously reported neurobehavioral evaluation procedures.

Immediate and long-term alterations in maximal electroshock seizure responsiveness in rats neonatally exposed to triethyltin bromide.

Neonatal rats were injected (sc) with 0, 0.25, 0.5, 1.0, 2.5, or 5.0 mg/kg triethyltin bromide (TET) in a 2% ethanol vehicle on Days 0, 5, 10, 15, and 20 postnatally. TET-exposed neonates exhibited a dose-dependent delay in the ontogenetic appearance of both the clonic and tonic maximal electroshock seizure (MES) responses which were apparent up to Day 45, as evaluated by the MES grade distributions and the durations of the individual phases of the MES. In marked contrast, adult rats (exposed to TET only as neonates) exhibited long-term increases in MES severity, as evaluated by the durations of the individual phases of the MES. At 75 days of age, a time when the 1.0 mg/kg developmentally TET-treated group exhibited an increased seizure severity, a single challenge dose of 1.0 mg/kg TET (ip) produced a proportional decrease in MES severity in both developmentally treated and control rats. No changes in preweaning or postweaning body weight were observed in the animals in the 0.25, 0.5, 1.0, or 2.5 mg/kg groups. A 30% decrease in weaning weight and an approximate 15% decrease in postweaning weight were observed in the 5.0 mg/kg group. These seizure results demonstrate that developmental exposure to TET produces immediate and long-term alterations in central nervous system functioning, which are of an opposite character. Interesting, we have previously shown that developmental lead exposure produces a similar developmental/adult dichotomy of effects with regard to the MES severity; however, the two patterns are reversed (D. A. Fox, S. R. Overmann, and D. E. Woolley (1979).

Effect of trimethyltin on chemically-induced seizures.

The effect of trimethyltin (TMT; 4.26 mg/kg i.p.), at 1 and 14 h following administration, on chemically-induced seizures in mice is reported. At 1 h following administration, TMT decreased seizure responsiveness and protected animals from bicuculline, isonicotinic acid hydrazide (INH) and pentylenetetrazol (PTZ) induced seizures. At 14 h following administration, TMT provided little protection against bicuculline, INH or PTZ induced seizures. Only slight decreases in seizure responsiveness were observed with strychnine induced seizures at either 1 or 14 h. By 16 h following administration, animals exhibited spontaneous tremors and convulsions. The results indicate that TMT exerts a biphasic effect on central nervous system excitability.

Antinociceptive and hypothermic effects of trimethyltin.

Trimethyltin (TMT) induced a dose-dependent antinociceptive and hypothermic effect in mice. Antinociception was not attenuated by naloxone but was reversed by atropine. TMT, however, was ineffective in displacing (3H)-QNB binding in vitro and did not affect (3H)-QNB binding or acetylcholinesterase activity after in vivo administration. The ethyl ester of nipecotic acid, a specific inhibitor of synaptosomal GABA uptake, exerted a similar antinociceptive effect that could be blocked by atropine. The GABA receptor antagonist bicuculline attenuated antinociception induced by TMT and nipecotic acid ethyl ester but not by morphine or oxotremorine. Gamma-Vinyl GABA, an irreversible inhibitor of GABA metabolism, prolonged TMT but not morphine-induced antinociception. In contrast, neither the dose-response nor the time course of TMT-induced hypothermia were affected by any of the drugs tested. The findings suggest that the GABAergic system may be involved in TMT induced antinociception; however, the mechanism responsible for the hypothermic effect of TMT is not apparent.

Effects of organotin compounds on maximal electroshock seizure (MES) responsiveness in mice. I. TRI(n-alkyl)tin compounds.

Male mice (25-30 g) were injected (ip) with 0, 3.5 X 10(-6), or 17.5 X 10(-6) mol trimethyltin bromide (TMT), triethyltin bromide (TET), tri-n-propyltin chloride (TPT), or tri-n-butyltin bromide (TBT) per kg. Additional groups of mice were also injected (ip) with either 0 or 17.5 X 10(-6) mol sodium bromide (NaBr) or 17.5 X 10(-6) mol stannic bromide (SnBr4) per kg. The mice were tested with maximal electroshock seizure (MES) at 0.5, 4, 21-24, and 96 h following exposure to the organotin compounds. Mice exposed to TMT, TET, TPT, or TBT exhibited dose-dependent decreases in MES severity as evaluated by seizure-grade distributions and duration of tonic seizure phases. The tri-n-alkyltin compounds exhibited a structure-activity relationship in their ability to decreased maximal responsiveness to the MES test. In order of decreasing ability they were: TMT greater than TET greater than TPT greater than TBT. Administration of NaBr and SnBr4 did not alter MES responsiveness, indicating the essential role of the alkyl moieties of the tri-n-alkyltin compounds in producing alterations in central nervous system function.

Effects of organotin compounds on maximal electroshock seizure (MES) responsiveness in mice. II. Tricyclohexyltin and triphenyltin.

Male mice (25-30 g) were injected (ip) with either 0, 3.5 X 10(-6), 17.5 X 10(-6), or 26.25 X 10(-6) mol/kg of either tricyclohexyltin bromide (TCT) or triphenyltin acetate (TPhT) in a corn-oil vehicle. The mice were tested for maximal electroshock seizure (MES) at 0.5, 4, 24, and 96 h following exposure to the organotin compounds, and the durations of seizure phases were measured and used to assess seizure severity. No significant changes in seizure-grade distribution, as compared to controls, were observed in any of the TCT- or TPhT-treated groups at any of the time points examined. No significant changes in the duration of seizure phases, as compared to controls, were observed in animals dose with 3.5 X 10(-6) mol/kg of TCT or TPhT at any of the time points evaluated. At 0.5 h following exposure, the mice dosed with the two higher levels of TCT or TPhT exhibited increases in MES severity. At 4 and 24 h following exposures, the mice exposed to the two higher dose levels of TPhT exhibited decreases in MES severity, followed by a recovery of normal seizure severity at 96 h. Conversely, the animals dosed with the higher dose levels of TCT exhibited at increased MES severity at 4, 24, and 96 h following exposure. These results, in combination with those in the preceeding paper (Doctor and Fox, 1982), reveal that at equimolar doses TCT And TPhT possess a different spectrum of action than the tri-n-alkyltins.

Trimethyltin inhibits uptake of neurotransmitters into mouse forebrain synaptosomes.

Trimethyltin (TMT), in a concentration dependent manner, inhibits in vitro uptake of gamma-aminobutyric acid (GABA), norepinephrine and serotonin by mouse forebrain synaptosomes with IC50S of 75, 43 and 24 microM, respectively. At 2 h and 14 h following in vivo administration of TMT (4.26 mg/kg; i.p.) to mice, GABA and serotonin uptake by forebrain synaptosomes are decreased, although norepinephrine uptake was not significantly affected. In vitro kinetic analyses of TMT inhibition of forebrain synaptosomal uptake of GABA, norepinephrine and serotonin indicated that the inhibition was not of the competitive type. This inhibition of uptake of neurotransmitters could be responsible, at least in part, for altered neurotransmitter levels in the synaptic cleft and may contribute to altered nervous system function during TMT intoxication.