Time course of the effect of amphetamine on eating is biphasic

The time course of the effect of 1, 2, and 5 mg/kg d-amphetamine sulfate on eating was recorded in independent groups of rats for 12 days with a measure that was sensitive to both increases and decreases in food consumption. The data from the initial drug treatment day suggest that the time course of the drug's effect was biphasic. Furthermore, during the test period, a clear biphasic temporal response developed to the 2- and 5-mg/kg doses. In both cases, on the last drug treatment day, the drug initially suppressed eating but later produced hyperphagia. The hyperphagic response that developed probably resulted from Pavlovian conditioning of compensatory adaptive responses.

Acute traumatic haemarthrosis of the knee: expectant treatment or arthroscopy?

We have prospectively studied 50 patients with an acute traumatic haemarthrosis of the knee to investigate the place of examination under anaesthesia and arthroscopy in a district general hospital. There was a wide spectrum of injury to the knee, and 30% of patients required operative procedures. These important injuries could not be diagnosed reliably on initial clinical examination. We conclude that in the active patient under 35 years of age this policy allows prompt and appropriate treatment.

Primary total hip replacement for displaced subcapital fracture of the femur

The results of primary total hip arthroplasty for sub-capital femoral neck fracture in previously normal hips are reported. Thirty-seven patients aged 70 or less at the time of surgery were reviewed at an average follow-up of 56 months. Eighteen (49%) had undergone or were awaiting revision surgery. A further four (11%) had definite radiological signs of loosening. Harris hip scores were calculated and correlated well with the results of gait analysis; these suggested that it was the more vigorous patients that were more liable to early failure. Consequently, primary total hip replacement is not recommended for subcapital fractures in the younger patient without pre-existing hip pathology.

Amphetamine's effects on food consumption and body weight: the role of adaptive processes

Three experiments were conducted to characterize the time course of amphetamine's effects on food consumption using procedures that would allow both decreases and increases in eating to be evident relative to control levels. In Experiment 1 we measured eating over 12 postinjection hr in rats. Orderly changes in within-day temporal patterns of eating over the 12 days of amphetamine administration suggest the role of conditioned adaptive processes. In Experiment 2, animals were not presented food until 2 hr after drug administration. Initial anorexia and subsequent hyperphagia were produced by repeated administration of amphetamine. Experiment 3 assessed both within-day and over-day changes in body weight and food consumption and showed that in addition to the drug's anorectic effect, amphetamine also reduces body weight via other mechanisms. In interpreting tolerance to anorectic drugs, it is necessary to evaluate such changes in body weight that indicate shifts in hunger that occur over days as well as shifts in within-day temporal patterns of eating that indicate the presence of conditioned adaptive changes. It is proposed that these two adaptive mechanisms account for pharmacodynamic tolerance.

Amphetamine's effects on food consumption and body weight: The role of adaptive processes

Three experiments were conducted to characterize the time course of amphetamine's effects on food consumption using procedures that would allow both decreases and increases in eating to be evident relative to control levels. In Experiment 1 we measured eating over 12 postinjection hr in rats. Orderly changes in within-day temporal patterns of eating over the 12 days of amphetamine administration suggest the role of conditioned adaptive processes. In Experiment 2, animals were not presented food until 2 hr after drug administration. Initial anorexia and subsequent hyperphagia were produced by repeated administration of amphetamine. Experiment 3 assessed both within-day and over-day changes in body weight and food consumption and showed that in addition to the drug's anorectic effect, amphetamine also reduces body weight via other mechanisms. In interpreting tolerance to anorectic drugs, it is necessary to evaluate such changes in body weight that indicate shifts in hunger that occur over days as well as shifts in within-day temporal patterns of eating that indicate the presence of conditioned adaptive changes. It is proposed that these two adaptive mechanisms account for pharmacodynamic tolerance.

Evidence of neurologic dysfunction related to long-term ethylene oxide exposure

Eight hospital workers with chronic ethylene oxide exposure were age-sex matched with eight nonexposed controls with no significant differences in educational backgrounds and vocabulary scores. The exposed group performed more poorly on all eight measures of cognition, memory, attention, and coordination, with 71.3% less accuracy on the Hand-Eye Coordination Test. There was a dose-response relationship between exposure and the following: Continuous Performance Test and sural velocity. These findings suggest that neurologic dysfunction may result from long-term low-dose exposure to ethylene oxide, and that these effects may occur at exposure levels common in hospital sterilizer operations.

Tendon implantation into bone: an experimental study

We report the results of an experimental study to investigate the mechanical properties and histological structure of the tendon-bone junction following surgical implantation of tendon into bone in the rabbit. The results following tendon transfer and tendon grafting were compared. The normal four-zone tendon junction was not reproduced histologically, in either group. After 20 weeks, the mechanical strength of the tendon transfers had reached 60% of the controls and that of the tendon grafts 20% of the controls. Microangiography demonstrated that these differences were not related to the vascularisation of the tendon bone junction. The mechanical properties of the tendon-bone junction may be dependent more on the functional state of the implanted tendon than on its structure.

Tendon Implantation into Bone: An Experimental Study

We report the results of an experimental study to investigate the mechanical properties and histological structure of the tendon-bone junction following surgical implantation of tendon into bone in the rabbit.

The results following tendon transfer and tendon grafting were compared.

The normal four-zone tendon junction was not reproduced histologically, in either group, After 20 weeks, the mechanical strength of the tendon transfers had reached 60% of the controls and that of the tendon grafts 20% of the controls.

Microangiography demonstrated that these differences were not related to the vascularisation of the tendon bone juction. The mechanical properties of the tendon-bone junction may be dependent more on the functional state of the implanted tendon than on its structure.

Fictitious epilepsy associated with amnesia

Epilepsy can occur in patients without any changes apparent in the electroencephalogram. Thus the diagnosis of epilepsy is essentially made on clinical grounds. The clinical features of epilepsy are rela tively easy to learn to mimic. Feigned epilepsy can occur in adulthood or it may occur in childhood, as part of a Munchausen syndrome by proxy as described by Meadows (1984). We would like to describe a case of feigned epilepsy with global amnesia, and several other symptoms of aberrant illness behaviour.

Synovial Chondromatosis Presenting with Peripheral Nerve Compression — A Report of Two Cases

We report two cases of synovial chondromatosis presenting with peripheral nerve compression syndromes involving respectively the median nerve at the wrist and the posterior interosseous nerve at the elbow. Only one previous instance of nerve compression due to this condition has been described, involving the ulnar nerve at the elbow.

In one of our cases the disease process was at an early stage in its natural history and in the other at an advanced stage. The occurrence of nerve compression was related to the site rather than the stage of the disease.

Full recovery followed local excision with decompression of the peripheral nerve involved.

Semiconductor manufacturing: an introduction to processes and hazards

Recent studies suggest that semiconductor workers have an increased incidence of work-related illness. Semiconductor manufacturing is a chemically intensive industry involving many potentially hazardous operations. As this industry moves into new geographic areas, health care professionals will be asked to evaluate medical or workplace conditions associated with unfamiliar and complex production processes. This paper provides an overview of semiconductor manufacturing processes for these health practitioners. Each step of device fabrication is detailed with its attendant chemical and physical hazards. Broader concepts of industrial control technology, clean room ventilation, and ergonomics are explained. The hazards are tabulated to allow rapid assessment of the risks inherent to each processing step. References have been chosen to guide the reader to more indepth information.

The locked knee

Fifty patients presenting themselves with a locked knee were investigated prospectively by examination under anaesthesia and arthroscopy. Definite abnormality was found in 92 per cent. Torn menisci were present in 68 per cent and isolated ruptures of the cruciate ligament in 10 per cent. Loose bodies were found in 3 patients, degenerative changes alone in 2 patients and a pathological medial synovial shelf in 1 patient. No abnormality was demonstrated in 8 per cent. Sixteen per cent of the knees remained locked following the induction of anaesthesia. This study demonstrates that a true mechanical block is not necessarily present and that the position of an unstable meniscal fragment is not consistently related to the fixed position of the knee under anaesthetic. There were no clinical features that allowed the normal knees to be distinguished preoperatively from those with internal derangement. It is proposed that these patients should be managed by prompt examination under anaesthesia, arthroscopy and definitive surgery.

Comparison of the binding of some carcinogenic and non-carcinogenic cyclopenta[a]phenanthrenes to DNA in vitro and in vivo

After microsomal activation in vitro, both the strong carcinogen 15,16-dihydro-11-methylcyclopenta[a]phenanthren-17-one and its inactive 12-methyl isomer bind covalently to added DNA, in the ratio approximately 6:1 (1595 and 254 mu mol/mol of DNA phosphorus, respectively). Over a thousand times less binding was observed when DNA was isolated from the skin of groups of mice that had received a topical dose of 1000 nmol of these two compounds, and of the unsubstituted ketone (non-carcinogen) and its 11,12-dimethyl derivative (carcinogen), 48 h previously; the binding ratios were 458, 155, 19 and 974 nmol/mol DNA phosphorus, respectively. Covalent binding of the 11-methyl compound to mouse skin DNA, measured 48 h after topical application, was linear with dose over the range 50 - 1000 nmol. It has previously been demonstrated for groups of mice initiated with 200 or 400 nmol of this carcinogen and promoted by repeated application of croton oil that skin tumour incidences were 50 and 70%, respectively. For a topical dose of 1000 nmol of the inactive 12-methyl isomer DNA binding in skin falls in this range, equivalent to DNA binding given by approximately 340 nmol of the carcinogen. Thus although the inactive unsubstituted parent compound essentially fails to bind to skin DNA after topical application, there does not seem to be a consistent relationship between extent of DNA binding in vivo and carcinogenicity among these cyclopenta[a]phenanthrenes. However, loss of the 12-methyl adducts from skin followed a logarithmic course over the first 10 days following application, with a half life of 3.5 days. In contrast, it was previously shown that removal of the 11-methyl adducts could not be measured above the normal rate of DNA turnover for this mouse tissue (half life, 6-7 days). It is suggested that active DNA repair of the 12-methyl lesions may contribute to the lack of activity of this isomer.

A comparative examination of the in vitro metabolism of five cyclopenta[a]phenanthrenes of varying carcinogenic potential

Metabolites of 15,16-dihydrocyclopenta[a]phenanthren-17-one and its 1- and 12-methyl homologues (all non-carcinogens) along with those from the 11-methyl and 11,12-dimethyl-17-ketones (carcinogens), produced in vitro by hepatic microsomes from methylcholanthrene induced rats, were separated by reverse phase h.p.l.c. Identifications of individual metabolites were based upon elution times, u.v. spectra, and in some cases by mass spectrometry, circular dichroism, and identity with synthetic derivatives. All five compounds were biologically oxidised at their terminal A and D rings to yield 1,2-dihydrodiols and 15- and 16- ols; with the exception of the 1-methyl compound, all also gave similar amounts of 3,4-dihydrodiols. The 1-methyl compound by contrast failed to produce this metabolite, furnishing instead the 4-phenol and five other, probably related phenolic derivatives. Previous work has established that for the 11-methyl-17-ketone, the 3,4-dihydrodiol is the proximate carcinogen. Thus, whereas lack of biological activity with the 1-methyl compound can be ascribed to its failure to produce a 3,4-dihydrodiol, in the case of the unsubstituted parent ketone and its 12-methyl derivative other determining factors must come into play.

Development and learning in the offspring of rats fed an alcohol diet on a short- or long-term basis

The offspring of rats fed a diet containing 12.5% (v/v) ethanol prior to, and during, gestation (LTE) were compared to the offspring of rats fed the same diet during gestation only (STE) in three studies. In Study I the neonates were tested on a variety of neuroreflex tasks, in Study II the offspring were tested in an activity wheel and open field, and in Study III the offspring were trained in a runway under partial or consistent reward conditions. Results indicated that STE offspring were delayed in developing fur and in opening their eyes, they righted more rapidly, and were slower in developing a reaction to and habituating to an auditory stimulus than their controls (STC) and the LTE offspring. Generally, movement was greater for ethanol exposed offspring and the LTE offspring showed more persistent fear-related responses than the STE offspring. No statistically reliable differences in learning or extinction were found among the groups, although a trend towards better learning and less resistance to extinction was noted in the LTE animals. Long-term alcohol use seems to attenuate the effects of gestational alcohol in rats.

The physical digestion of perennial ryegrass (Lolium perenne) and white clover (Trifolium repens) in the foregut of sheep

Sheep were fed once daily with 300 or 600 g dried perennial ryegrass (Lolium perenne) or white clover (Trifolium repens). Total rumen contents were sampled once daily at various intervals up to 24 h after feeding for 6 d. Total weight of fresh rumen contents and dry matter (DM), organic matter and particulate matter concentrations were measured and the particle size distribution of rumen contents was analysed using a wet sieving technique. There was a similar exponential loss of DM from the rumen with time after feeding for both perennial ryegrass and white clover. The rate of DM disappearance during the first 3 h after feeding was ten times greater for the higher intake and seven times greater for the lower intake than during the subsequent 21 h. The percentage of particulate material disappearing during the first 3 h was greater for white clover (57%) than for perennial ryegrass (49%). Particle size distribution analysis of rumen contents showed that the most rapid rate of particle size reduction occurred during the first 3 h after feeding. Despite a rapid rate of breakdown there was no increase in the total weight of small particles in the rumen. The rate of reduction in particle size during this period was greater for white clover than perennial ryegrass. Microscopic examination of rumen particles showed a difference in particle geometry between white clover and perennial ryegrass which appeared to be related to anatomical features of the plant.

A study of the communicating branch between the medial and lateral plantar nerves

A study of the communicating branch between the medial and lateral plantar nerves was carried out on the feet of 20 cadavers. The nerve was found to be present in all the feet examined, but in two women it was considerably enlarged bilaterally. It is suggested that this enlarged communicating branch may be a factor responsible for the frequent involvement of the nerve to the third interspace by Morton's neuroma.

Effects of cooking fuels on lung function in nonsmoking women

A case-control study of 20- to 39-yr-old female participants in the Tecumseh Community Health Study compared use of cooking fuels and other factors in women from the highest and lowest quartiles of the lung function distribution. The forced expiratory volume in 1 second (FEV1.0) was used as the index of ventilatory lung function. The use of a kitchen exhaust fan was significantly associated with low lung function. A larger proportion of women with low FEV1.0 used gas for cooking, but this difference was not statistically significant.

Sequential clomiphene citrate-menotropin therapy for induction or enhancement of ovulation

Either to induce ovulation in anovulatory infertility patients or to enhance ovulation in patients with mild endometriosis or luteal phase inadequacy, we utilized a sequential regimen of low-dose clomiphene citrate (CC) followed by human menopausal gonadotropin (hMG) injections on alternate days; duration and dosage of menotropin therapy was individualized by using serum estradiol levels for monitoring until the time of administration of human chorionic gonadotropins. Previous therapeutic efforts without menotropins had been unsuccessful in all patients. One third of 70 treated patients conceived during 156 treatment cycles. The pregnancy rate was 44% in anovulatory patients (n = 34), and 26% in patients with ovulation dysfunction (n = 23). Pregnancy rates declined with patient's age. Four of the 23 patients that conceived had a spontaneous abortion (17%). The multiple gestation rate was 10.5%. A relative inhibition of cervical mucus development was noted and shown to be caused by CC. Hyperstimulation occurred in three patients. The discussed CC-hMG regimen approaches the effectiveness of standard hMG therapy; but compared with standard hMG therapy, it has significant economic advantages and seems to have a markedly lower rate of multiple gestation. However, like standard hMG therapy, CC-hMG therapy requires careful monitoring specifically, because hyperstimulation may occur.

Hyperprolactinemia and headaches

We investigated the frequency of headaches in women with menstrual abnormalities and hyperprolactinemia. Twenty-seven of 46 (58%) women with hyperprolactinemia indicated that headache episodes occur once or more per week; patients with sellar abnormalities (macroadenoma) or previous cranial or pituitary operation were excluded from this group of hyperprolactinemic patients. The headache episodes occurred significantly more frequently than in the control group (N = 56), where 27% indicated one or more headaches per week (p less than 0.01). In the vast majority of the women with hyperprolactinemia, headaches had preceded the finding of elevated prolactin levels for years and had not developed after the patients had become concerned about the pituitary gland. The clinical impression was that the headaches of these patients typically lack features of prodromal signs and unilaterality and resemble, in general, tension headaches; they may last for hours and often require medication. We could not demonstrate a relationship between prolactin levels and frequency or severity of these headache episodes. The etiology of these headaches is unclear. The therapeutic effect of bromocriptine deserves further investigation. In conclusion, we present data to suggest that headaches are commonly an associated finding in hyperprolactinemic women who have no evidence of significant pituitary enlargement.

Antenatal diagnosis of sickle cell disease: amniotic fluid cell DNA analysis

Using recombinant DNA methods and amniocentesis, the antenatal diagnosis of sickle cell disorders can be accomplished. This article presents the authors' experiences with 21 pregnancies at risk using HpaI and Hind III restriction enzyme digestions of adult leukocytic and fetal amniotic fluid cell DNA. The authors were able to establish direct beta A- and beta S-globin gene linkages to the restricted fragments in 9 families. In 8 families no direct linkages could be determined and estimates of exclusion of fetal beta S homozygosity were used. These estimates were made on the basis of the frequencies of association of the HpaI fragments with the beta S and beta A genes in the Afro-American population. In 4 families, no estimates or linkages could be established, and the patients were counseled in reference to fetoscopy. The data also indicated the frequencies of association of the HpaI fragments with the beta A and beta S gene in the New Jersey-New York population. These studies did not seem to indicate any exclusive preferential segregation of the HpaI and Hind III polymorphisms.

Oral contraceptive exposure of amenorrheic women with and without prolactinomas

The purpose of this study was to determine the extent of oral contraceptive (OC) exposure of women with secondary amenorrhea of hypothalamic-pituitary etiology. In 93 of 126 women with secondary amenorrhea sufficient data were obtained regarding menstrual history and OC exposure: 26 patients had evidence of a prolactinoma, an additional 26 patients had idiopathic hyperprolactinemia without evidence of a pituitary tumor, and 41 had "pure" dysfunction hypothalamic-pituitary amenorrhea. After stratification by age at diagnosis and parity the estimated odds ratio for past oral contraceptive usage showed no differences among the three groups (odds ratios between 0.74 and 1.48). Using the chi-square test the proportion of subjects who had regular menses before oral contraceptive intake and developed anovulation immediately after discontinuance ("post pill amenorrhea") in the three groups also showed no difference (x2 = 0.60, P = 0.74). These data indicate that non-ovulatory patients are likely to have been exposed to OC, and do not indicate that patients with prolactinomas differ in the extent of their OC exposure from other specified groups of patients with secondary.

Induction of ovulation with menotropins in women with polycystic ovary syndrome

Twenty-four women with ovulatory infertility as a result of surgically or biochemically documented polycystic ovary syndrome (PCO) who had failed to conceive during clomiphene citrate therapy underwent a closely supervised menotropin treatment to induce ovulation. Evidence of ovulation was obtained in all patients treated, and major side effects were limited. Fourteen women conceived after an average of 2.4 treatment cycles; twin pregnancies occurred in 36% and spontaneous abortions occurred in 21%. Initial treatment cycles tended to be less successful than the subsequent treatment cycles. Serum 17 beta-estradiol (E2) levels were significantly augmented in the last 3 days before administration of chorionic gonadotropins (hCG) in treatment cycles resulting in conception compared to E2 levels in those cycles which resulted in ovulation only. A second hCG administration to trigger ovulation had to be given in 27% of the treatment cycles and seemed to be an indication of a less promising treatment cycle. Treatment cycles resulting in twin gestations did not differ from those resulting in singleton gestations; specifically, the E2 response was not increased. In summary, under a closely monitored regimen, menotropin therapy can be used in women with nonovulatory infertility as a result of PCO with considerable effectiveness and relative safety once clomiphene citrate treatment has failed.

Hyperprolactinemia

The ability to measure serum prolactin levels has led to the characterization of hyperprolactinemia as a clinical entity. In women galactorrhea and amenorrhea are symptoms of elevated prolactin levels; in men, impotence seems to be a clinical correlate. In the differential diagnosis, concern about the presence of a pituitary adenoma is preeminent. Management of microadenomas is controversial; both active therapy and conservative follow-up have been advocated. For larger lesions, neurosurgery or radiation becomes necessary. Drug therapy to reduce prolactin levels is now available.

Estrogenization in women with postmenopausal ovarian hyperthecosis

The cases of two women who show postmenopausal bleeding and signs of endogenous estrogen production are presented. At laparotomy, ovarian hyperthecosis was found and confirmed histologically. Determination of 17 beta-estradiol concentrations in ovarian and peripheral veins suggested that these ovaries actively secreted excessive estrogens. Ovarian hyperthecosis is discussed as a cause of renewed endogenous estrogen activity in the postmenopausal women.

Hyperprolactinemia and primary amenorrhea

Four women with primary amenorrhea and hyperprolactinemia are presented. These patients started thelarchal and pubarchal development but never had a spontaneous menses. Hypothyroidism was not demonstrable in these patients. The causes for hyperprolactinemia in these patients and the clinical follow-up are discussed. In the authors' experience, hyperprolactinemia is seen in about one third of women with normogonadotropic primary amenorrhea, and primary amenorrhea is seen in about 3% of women with hyperprolactinemia.