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Biomedical subjects

J Herbert

Publications and source records attributed to J Herbert.

At least 217 records · Page 12Linked to original sources

Epidemiology of hepatic angiosarcoma in the United States: 1964-1974.

A nationwide survey of hepatic angiosarcoma (HAS) in the United States during the years 1964 through 1974 identified 168 cases. Of these, 42 cases (25%) were associated with known etiologic factors, such as vinyl chloride monomer exposure during preparation of poly(vinyl chloride), use of Thorotrast in angiography, exposure to inorganic arsenic, and treatment with androgenic-anabolic steroids; 126 cases (75%) are of uncertain etiology. HAS most often affects males (ratio of approximately 3:1), peaks in the sixth and seventh decades of life (somewhat earlier than other sarcomas of the liver) and appears to occur more often in the industrialized Northeast and Midwest (although reporting artifact may be a factor). There is an extraordinary relative risk for poly(vinyl chloride) polymerization workers; there may also be other chemical-industrial associations that require further investigation. Prospective epidemiologic studies of HAS should be considered as a means of identifying other causative factors (e.g., chemicals or drugs) related to HAS.

Adolescent↗

Behavioural and endocrine effects of naltrexone in male talapoin monkeys.

The effect of treating captive male talapoin monkeys with naltrexone hydrochloride (500 micrograms/kg intra-muscular injection twice daily) was studied both in socially living and singly caged animals. The behaviour of the group males and endocrine changes in all treated animals were monitored during the course of treatment and on drug withdrawal. Naltrexone significantly reduced sexual behaviour in previously active males, while increasing grooming interactions. Aggressive behaviour did not change. There was an overall significant elevation in testosterone, LH and cortisol during drug treatment and a significant decrease on withdrawal. Changes in prolactin in response to naltrexone depended upon the pre-treatment level of this hormone: in males in which levels were low, there was a significant elevation in prolactin, while in those with high pre-treatment prolactin, levels were unchanged by the drug. The behavioural changes reported for this primate are in direct contrast to changes reported in rodents, while the hormonal changes, except for prolactin, are comparable to others reported.

Aggression↗

Hepatosplenomegaly as a manifestation of quinidine hypersensitivity.

A 75 year-old man developed fever after one month of quinidine administration 800 mg/day. Significant enlargement of the liver and spleen became evident, associated with marked rise in serum GOT, GPT and alkaline phosphatase. Arthritis also developed, but there was no skin rash nor any changes in the haemoglobin, leucocytes or platelets. The signs and biochemical findings regressed within a few days of stopping quinidine and the temperature became normal. Rechallenge with four doses of the drug produced a rise in the GOT, GPT and alkaline phosphatase. It is thought that this hypersensitivity response is consistent with the description of granulomatous hepatitis, and represents a much less common manifestation of quinidine hypersensitivity than the well known skin, gastro-intestinal and haematological side-effects.

Aged↗

The effects of different photoperiods on circadian 5-HT rhythms in regional brain areas and their modulation by pinealectomy, melatonin and oestradiol.

Differential circadian rhythms in 5-HT levels were found in the hypothalamus and pineal (but not in the cortex, hippocampus or midbrain) in ferrets kept in either long (14 h light/10 h dark) or short (8 h light/16 h dark) photoperiods. 5-HT decreased during the first 6 h of illumination in all areas examined from animals kept in short photoperiods. In long photoperiods, 5-HT in the hypothalamus (particularly the anterior region) increased during the first 6 h after onset of light and levels in the pineal became arrhythmic. There were no differential effects of light on 5-HIAA/5-HT ratios. Removal of the pineal or the superior cervical ganglia abolished these differential rhythms, as did subcutaneous implants of oestradiol (releasing about 5 micrograms/day). Melatonin (1 mg/day) injected 8 h after the onset of light into animals kept in long photoperiods resulted in circadian 5-HT rhythms resembling those from animals exposed to short photoperiods, whereas melatonin given at 14 h after onset of light did not have this effect. It is suggested that 5-HT containing neural systems may play a role in the way the pineal transmits information about the duration of the photoperiod to the neural structures controlling the pituitary.

Animals↗

Detection of protein A-like substances on haemolytic streptococci prior to use in mixed reverse passive antiglobulin haemagglutination (MRPAH).

Before mixed reverse passive antiglobulin haemagglutination tests (MRPAH) can be used to measure the class of bacterial antibodies, the bacteria have to be shown to be free of Protein A or Protein A-like substances on their surfaces. Two basic procedures have been examined: haemagglutination of red cells coated with immunoglobulin by the bacteria, and the MRPAH reaction itself to reveal absorption of purified gamma Fc by the bacterial suspension. The use of a purified gamma Fc component has proved successful in providing a sensitive test for the detection of Protein A-like substances on the surface of bacterial. In addition to both the Cowan and Wood strains of Staph, aureus, strains of haemolytic streptococci of groups A, C and G had Protein A-like substances on their surfaces. In contrast, strains of group B and group D, as well as Strep. milleri, had no detectable Protein A-like activity.

Absorption↗

Recurrent breeding seasons in pinealectomized or optic-nerve-sectioned ferrets.

The breeding seasons of two groups of pinealectomized ferrets and one group of blind ferrets, with appropriate controls, were observed for up to 5 years after the operations. All animals showed recurrent breeding seasons. Both pinealectomized and blind animals became increasingly asynchronous after the first season, but showed no evidence of a free-running, endogenous circannual periodicity nor of synchronization to light or other environmental cues.

Animals↗

Hormonal basis of proceptivity and receptivity in female primates.

The role played by steroid hormones in regulating the sexual behavior of female primates is reviewed, with emphasis placed on experiments using nonhuman species. A distinction is made between the effects of hormones on female proceptivity (i.e., behaviors which incite mounting activity in the male) and receptivity (i.e., willingness to accept male mounting attempts). The rationale for distinguishing between proceptivity and receptivity is discussed, and the methods used for measuring each are described. Evidence shows that estrogen of ovarian origin facilitates sexual interaction primarily by stimulating the emission of non-behavioral cues which increase the female's sexual attractivity (i.e., the value of a female as a sexual stimulant for a male). Evidence is presented suggesting that ostrogen may enhance proceptivity by acting on the female's central nervous system; however, there is no clear demonstration that estrogen affects neural mechanisms controlling receptivity. Experiments show that proceptivity and to a lesser extent receptivity are modulated by adrenal androgens, and the possibility is raised that adrenal androgens may act synergistically with estrogen to facilitate sexual behavior. A disruptive effect of progesterone on sexual interaction is described, and evidence is presented suggesting that this effect of progesterone results primarily from a reduction in sexual attractivity caused by the action of the hormone in the female's vagina. Other literature indicates that proceptivity is often maximal at the periovulatory period of the female primate's menstrual cycle whereas cyclic variations in receptivity occur infrequently. Most hormone-dependent changes in sexual interaction associated with the menstrual cycle seem to result from fluctuations in nonbehavioral attributes of female sexual attractivity. The problem of distinguishing between the effects of steroid hormones on proceptivity and receptivity in human females is discussed.

Androgens↗

Practical bacteriologic monitoring of the burn victim.

A comprehensive picture of the burn wound microflora is now possible as a result of recent technologic advances. The microflora of the burn wound can be characterized with respect to its number, type, location, and antibiotic sensitivity. These parameters can be measured in sufficient time to influence the decision of the burn surgeon. The microflora of the surface of the burn wound and the burn wound itself are examined separately by different sampling techniques. For the surface microflora, the gauze capillary techniques employed, while incisional biopsies are used to monitor the organisms in the burn wound. After sampling, suspensions of the specimens are created which in turn are subjected to direct microscopic measurement, quantitative culture procedures, and immediate antibiotic sensitivity testing. Histologic examination of the burn wound is performed concomitantly with this bacteriologic examination to determine the depth of bacterial invasion as well as to detect the presence of either mycotic or herpetic infections.

Animals↗

The accessory optic system of the ferret.

The accessory optic system of the ferret has been studied both by silver degeneration staining and by autoradiography after intraocular 3H leucine injections. There is no anterior accessory optic tract but a posterior tract containing only crossed fibres leaves the brachium of the superior colliculus and ends in the two nuclei, the medial and lateral terminal nuclei, lying either side of the cerebral peduncle. Both suprachiasmatic nuclei receive retinal fibres visible only on autoradiographs; most fibres end in the contralateral nucleus. No other area in the hypothalamus appears to receive retinal fibres demonstrated by these methods.

Animals↗

The effect of lesions of the accessory optic tract terminal nuclei on the gonadal response to light in ferrets.

Electrolytic lesions were made in the lateral (LTN), medial (MTN) or in both terminal nuclei of the accessory optic tract in female ferrets. Either the ipsilateral or contralateral eye was removed. Complete destruction of both nuclei, as assessed by both histological and autoradiographic criteria, did not prevent the acceleration of estrus by artificial long days (L:D, 14:10) in any animal. Although the ferret has no anterior (inferior) accessory tract, lesions were also made in the medial forebrain bundle (MFB) area in ipsilaterally and contralaterally enucleated animals. Estrus still occurred in response to artificial long days in these animals. The experiments suggest that the accessory optic system in the ferret does not transmit information to the pineal regulating the annual breeding season.

Animals↗